Papers by Alcides Pérez Bello
Proceedings of MOL2NET, International Conference on Multidisciplinary Sciences, 2015
This communication shows a classification model for prediction of mycobacterial promoter sequence... more This communication shows a classification model for prediction of mycobacterial promoter sequences (mps), which constitute a very low sequence homology problem. The model developed (mps =-4.664• 0 ξM + 0.991• 1 ξM-2.432) was intended to predict whether a naturally occurring sequence is an mps or not on the basis of the calculated k ξM value for the corresponding RNA secondary structure. The model predicted 115/135 mps (85.2%) and 100% of control sequences (cs). The detailed results have been published in detail in: Bioorg Med Chem Lett. 2006 Feb;16(3):547-53, the present is a short communications.
Proceedings of The 9th International Electronic Conference on Synthetic Organic Chemistry, 2005
The general belief is that quantitative structure-activity relationships (QSAR) techniques work o... more The general belief is that quantitative structure-activity relationships (QSAR) techniques work only for small molecules and, proteins sequences or, more recently, DNA sequences. However, with non-branched graph for proteins and DNA sequences the QSAR often have to be based on powerful non-linear techniques such as support vector machines. In our opinion linear QSAR models based in RNA could be useful to assign biological activity when alignment techniques fail due to low sequence homology. The idea bases in the high level of branching for the RNA graph. This work introduces the so called Markov electrostatic potentials k ξ M as a new class of RNA 2D-structure descriptors. Subsequently, we validate these molecular descriptors solving a QSAR classification problem for mycobacterial promoter sequences (mps), which constitute a very low sequence homology problem. The model developed (mps =-4.664• 0 ξ M + 0.991• 1 ξ M-2.432) was intended to predict whether a naturally occurring sequence is an mps or not on the basis of the calculated k ξ M value for the corresponding RNA secondary structure. The RNA-QSAR approach recognises 115/135 mps (85.2%) and 100% of control sequences. Average predictability and robustness were greater than 95%. A previous non-linear model predicts mps with slightly higher accuracy (97%) but uses a very large parameter space for DNA sequences. Conversely, the k ξ M-based RNA-QSAR encodes more structural information and needs only two variables.
Revista Cientifica, Facultad de Ciencias Veterinarias, Universidad del Zulia, 2018
Revista de Producción Animal, 2020
Antecedentes: El uso de aceite esencial de orégano es una alternativa viable en las dietas de ave... more Antecedentes: El uso de aceite esencial de orégano es una alternativa viable en las dietas de aves, como promotor de crecimiento. El objetivo de este estudio fue evaluar el efecto de la adición de aceites esenciales de orégano (AEO) en la dieta alimenticia y el sexo sobre el comportamiento productivo del pollo de engorde. Métodos: Se utilizaron 400 pollos de un día de edad de la línea genética Cobb 500®, distribuidos en cinco tratamientos (T1- Control sin aditivo; T2- 300 mg/kg de Zinc Bacitracina; T3- 100 mg/kg de AOE; T4- 200 mg/kg de AEO y T5- 300 mg/kg de AEO) con cuatro repeticiones, sobre el peso vivo, ganancia de peso acumulada, consumo de alimento, conversión alimenticia y rendimiento de la canal, en ambos sexos. Resultados: El peso vivo, la ganancia de peso y la conversión alimenticia fueron influenciados (P < 0,05) por los tratamientos, en el T5 se obtuvieron los mejores promedios. Se observó interacción (P < 0,05) entre los tratamientos y el sexo, para el peso vivo,...
Background: The association of trait heritability with milk production, breeding, and longevity, ... more Background: The association of trait heritability with milk production, breeding, and longevity, was thoroughly studied in the past decade. However, the efficiency of productive and reproductive performance is determined by the action of environmental factors and inappropriate husbandry. Therefore, the main reproductive indicators and environmental factors affecting cow genotypes Cuban Siboney and Cuban Mambi were evaluated at a genetic breeding company in central Cuba. Methods: The individual records of 618 females were processed between 2007 and 2010 (358 Cuban Mambi from six different herds, and 260 Cuban Siboney from four farms). The calving-first insemination service (CFIS) intervals, the calving-gestation (CG) interval, and the calving interval (CI) were determined. The effects of various factors on the reproductive indicators were estimated using a general linear model. Results: The farm factor had a significant influence (P < 0.05) on CFIS, CG, and CI in both genotypes. C...
In order to determine the reference parameters for the main biochemical indicators of the white-t... more In order to determine the reference parameters for the main biochemical indicators of the white-tailed deer, ( Odocoileus virginianus ustus...
Background: The association of trait heritability with milk production, breeding, and longevity, ... more Background: The association of trait heritability with milk production, breeding, and longevity, was thoroughly studied in the past decade. However, the efficiency of productive and reproductive performance is determined by the action of environmental factors and inappropriate husbandry. Therefore, the main reproductive indicators and environmental factors affecting cow genotypes Cuban Siboney and Cuban Mambí were evaluated at a genetic breeding company in central Cuba. Methods: The individual records of 618 females were processed between 2007 and 2010 (358 Mambí de Cuba from six different herds, and 260 Siboney de Cuba from four farms). The calving-first insemination service (CFIS) intervals, the calving-gestation (CG) interval, and the calving interval (CI) were determined. The effects of various factors on the reproductive indicators were estimated using a general linear model. Results: The farm factor had a significant influence (P < 0.05) on CFIS, CG, and CI in both genotypes. Calving years had a significant effect (P < 0.05) on CFIS, CG, and CI, with the best results in 2009 and 2010. The best calving quarter for reproductive indicators was the July-August-September period, with a significant influence (P < 0.05) on CFIS, CG, and CI, in Mambi de Cuba, whereas Siboney de Cuba influenced the CFIS. Conclusions: The two genotypes showed a remarkable deterioration of the reproductive indicators evaluated, particularly influenced by farm, calving year, and calving quarter.
The aim of this paper was to evaluate the reproductive behavior of female Zebu and 5/8 Zebu x 3/8... more The aim of this paper was to evaluate the reproductive behavior of female Zebu and 5/8 Zebu x 3/8 Simmental on a genetic farm in the central region of Cuba. The research was made between 2010 and 2014. The individual records of 255 cows; 200 Zebus (106 white and 94 bermeja) and 55 crossbreds (5/8 Zebu x 3/8 Simmental) were included. The calving-first insemination interval (CFII), calving-gestation interval (SP), inter-calving period (CCI), and service per gestation (S/G) were calculated. Besides, the effects of genotype, parity, quarter and calving year were evaluated using the above indicators. The descriptive statistics were estimated, and a general linear model was used to determine the effects of each variation source. The three genotypes showed low reproductive efficiency, though slightly more favorable for 5/8 Zebu x 3/8 Simmental. The CFII, SP, and CCI were influenced (P <0.05) by the calving year, genotype, and parity, whereas SP was influenced by the calving quarter only (P <0.05). The gestation service was not affected by any factor. It was concluded that the three genotypes studied underwent severe deterioration of reproductive indicators, influenced by the genotype, quarter, calving year, and parity.
In order to determine the reference values for the hematological parameters of the white-tailed d... more In order to determine the reference values for the hematological parameters of the white-tailed deer (Odocoileus virginianus ustus) at the Cotopaxi National Park, Ecuador, 36 animals, 17 males and 19 females, between 3 and 5 years of age, were used. The hematological parameters, their reference values and the effect of the sex and the district on them were determined. The descriptive statistic of the parameters was determined. The Shapiro-Wilk test of normality and the the chi-square (c²) goodness-of-fit test were used to determine the type of distribution of the data. In variables with normal distribution, the reference values for ± 1.65 standard deviations were calculated, and when the adjustment to normal distribution was not satisfactory, the limits of tolerance for 90% of the population were calculated. The effect of sex and the district on the hematological parameters were evaluated by means of a multifactorial analysis of variance. The erythrocytic series showed higher values...
[email protected] RESUMEN El objetivo fue evaluar el comportamiento reproductivo de hembras d... more [email protected] RESUMEN El objetivo fue evaluar el comportamiento reproductivo de hembras de los genotipos Cebú y 5/8 Cebú x 3/8 Simmental en una granja genética de la región central de Cuba. La investigación se desarrolló entre los años 2010 y 2014. Se consideraron 255 registros individuales de vacas; 200 y 55 hembras de los genotipos Cebú (106 de la variedad blanca y 94 bermeja) y 55 del 5/8 Cebú x 3/8 Simmental, respectivamente. Se calcularon los intervalos partoprimera inseminación (IPPS), parto-gestación (IPG) y periodo interpartal (IPP) y servicios por gestación (S/G). Además, se evaluaron los efectos del genotipo, la paridad, el trimestre y año del parto sobre los indicadores antes mencionados. Se calcularon los estadígrafos descriptivos de los indicadores y para determinar el efecto de cada fuente de variación sobre ellos se empleó un modelo lineal general. Existió baja eficiencia reproductiva en los tres genotipos, con una situación más favorable en el 5/8 Cebú x 3/8 ...
Este estudio se realizo para investigar el efecto de las vitaminas C y E en algunos electrolitos ... more Este estudio se realizo para investigar el efecto de las vitaminas C y E en algunos electrolitos de plasma de gallinas ponedoras durante el verano en clima caliente-humedo. Setecientas veinte aves White Leghorn (L33) de 39 semanas de edad se dividieron en cuatro grupos de 180. Un grupo se alimento con dieta basal (control) y los grupos de tratamiento se alimentaron con dieta basal suplementada con 150 mg de acido l-ascorbico/kg de dieta (grupo de la vitamina C), 150 mg de α-dl-tocoferol acetato/kg de dieta (grupo de la vitamina E), mientras que el ultimo grupo recibio 150 mg de l-acido ascorbico/kg de dieta mas 150 mg de α-dl-tocoferol acetato/kg de dieta (grupo de las vitaminas C + E). Las concentraciones de calcio y fosforo fueron menor (P < 0.05) en el grupo control comparado con los grupos suplementados. Contrariamente, la concentracion de magnesio fue significativamente mayor (P < 0.05) en todos los grupos experimentales comparados con el grupo tratado con vitamina C. Ade...
Probiotic microorganisms represent a positive effect for porcine production; the inclusion of the... more Probiotic microorganisms represent a positive effect for porcine production; the inclusion of these bioproducts in adequate amounts acts positively on animal health. The effect of biopreparations on the bioproductive behavior of breeding sows and their offspring. Twelve breeding sows (Landrace / Yorkshire) distributed in three groups of four animals each were used: Control, Bioprepared (T1) and Bioprepared (T2). T1 contained Lactobacillus acidophilus and Streptoccus thermophilus and T2, Saccharomyces cerevisiae and Kluyveromyces fragilis (L-4 UCLV). A completely randomized design was used. It was evaluated: weight gain (WG), birth weight of piglets, average daily gain (ADG), weight loss in lactation (WLL), occurrence of diarrhea in piglets, hemochemistry changes in the last third of gestation and lactation. Birth weight, WG and ADG was higher (P<0.05) in T1 and T2, without variation between them. The WLL was higher in control. The occurrence of diarrhea and deaths was lower (P<...
Archives Animal Breeding, 2010
This study was carried out to investigate the effects of vitamins C and E on some plasma metaboli... more This study was carried out to investigate the effects of vitamins C and E on some plasma metabolites and production performance of layer chickens reared under hot tropical climate. 720 White Leghorn (L 33) layer chickens and 39 weeks old were divided into four groups of 180 birds. One group was fed with basal diet (control) and treatment groups were fed with basal diet supplemented with 150 mg of vitamin C/kg of diet, 150 mg of vitamin E/kg of diet, while the last group was supplemented with 150 mg of vitamin C/kg of diet plus 150 mg of vitamin E/kg of diet. Separately or as a combination, supplemental vitamin C and E decreased plasma concentrations of cholesterol, glucose and creatine phosphokinase (P<0.001) compared to control. There were no significant (P>0.05) effects of supplemental vitamin C and E on plasma metabolites of alanine phosphatase and aspartate transaminase. The single supplementation of vitamin E and its combination with vitamin C considerably increased the plasma metabolite of protein (P<0.01). Egg/bird were significantly (P<0.05) higher in all treatment groups compared to control, but P value was highest in vitamin E treated group. The laying index showed a significant (P<0.05) increase in all treatment groups compared to control. Similarly, feed consumption and conversion were significantly (P<0.05) different in treatment groups compared to control. It is concluded that supplementation of vitamins C and E maintained the stability of some plasma metabolites concentration, thereby, sustained production performance and facilitated adaptation of chicken to stressful hot-humid condition.
Revista MVZ Córdoba, 2017
Objetivo. Evaluar el efecto de la suplementación del cobre por vía parenteral sobre la cupremia y... more Objetivo. Evaluar el efecto de la suplementación del cobre por vía parenteral sobre la cupremia y ganancia de peso en toros en ceba. Materiales y métodos. Se seleccionaron 50 animales mestizos Holstein x Cebú con 18 a 20 meses de edad, 210-220 kg de peso vivo, clínicamente sanos y en un sistema de ceba intensiva. Se dividieron 2 grupos de 25 animales, uno control y otro suplementado con 50 mg de Cu por vía parenteral cada 2 meses hasta completar 3 aplicaciones; se evaluaron los indicadores hematoquímicos y la ganancia de peso. Las variables se compararon mediante la prueba de t-Student para muestras independientes y se determinaron las curvas de crecimiento y sus parámetos. Resultados. La suplementación con Cu incrementó (p<0.001) la cupremia, la hemoglobina y el hematocrito y (p<0.01) la ganancia media diaria y el peso vivo de los toros, con incrementos del mismo entre el 4.86 y 9.54 %,a favor del grupo tratado. El peso vivo final (446 y 586 kg) y la ganancia media diaria de ...
Revista Brasileira de Ciência Avícola, 2010
A 30-day experiment involving 720 White Leghorn (L33) layer chickens of 39 weeks of age and avera... more A 30-day experiment involving 720 White Leghorn (L33) layer chickens of 39 weeks of age and average live weight of 1.8 ± 0.04 kg was carried out in a completely randomized design to evaluate the effects of vitamins C and E on erythrocyte parameters of layers during natural summer conditions. Birds were allotted to 4 treatments containing 0, 150 mg vitamin C, 150 mg vitamin E, and 150 mg vitamin C plus 150 mg vitamin E/kg feed. Each treatment was replicated four times. The exposure of layers to 31±3 °C and 33±0 °C ambient temperature and 84.6% and 81.5% relative humidity, inside and outside the experimental pen, during the study period caused an increase in temperature humidity index 15.5 above the threshold value of 70 established for this species. Total erythrocytes counts were not affected by treatment. However, hematocrit and hemoglobin were significantly (p<0.001) different in vitamin-C and E treated groups, individually or in combination, as compared to the control birds. Also, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration of the birds fed vitamins C or E, or vitamins C+E were significantly (p<0.001) higher than those in control group. The results of the present study showed that the dietary supplementation of vitamin C and E, particularly as a combination, alleviated the counterproductive effects of high ambient temperature and humidity on the birds.
Polymer, 2005
ABSTRACT The spherical truncation of electrostatic field with different functions break down long... more ABSTRACT The spherical truncation of electrostatic field with different functions break down long-range interactions at a given cutoff distance (roff) resulting in short-range ones. Consequently, a Markov Chain model may approach to the entropies of spatial distribution of charges within the polymer backbone. These entropies can be used to predict polymers properties [González-Díaz H, Molina RR, Uriarte E. Polymer 2004; 45: 3845 [53]]. Herein, we explore the effect of abrupt, shifting, force shifting, and switching truncation functions on QSAR models classifying 26 proteins with different function: lysozymes, dihydrofolate reductases, and alcohol dehydrogenases. Almost all methods have shown overall accuracies higher than 85% instead of 80.8% for models based on physicochemical parameters. The present result points to a acceptable robustness of the Markov model for different truncation schemes and roff values. The results of best accuracy 92.3% with abrupt truncation coincides with our recent communication [Bioorg Med Chem Lett 2004; 14: 4691–4695]. Nonetheless, the simpler model with three variables and high accuracy (88%) was derived with a shifting function and roff=10 Å.
Journal of theoretical biology, Jan 7, 2009
The importance of the promoter sequences in the function regulation of several important mycobact... more The importance of the promoter sequences in the function regulation of several important mycobacterial pathogens creates the necessity to design simple and fast theoretical models that can predict them. This work proposes two DNA promoter QSAR models based on pseudo-folding lattice network (LN) and star-graphs (SG) topological indices. In addition, a comparative study with the previous RNA electrostatic parameters of thermodynamically-driven secondary structure folding representations has been carried out. The best model of this work was obtained with only two LN stochastic electrostatic potentials and it is characterized by accuracy, selectivity and specificity of 90.87%, 82.96% and 92.95%, respectively. In addition, we pointed out the SG result dependence on the DNA sequence codification and we proposed a QSAR model based on codons and only three SG spectral moments.
Chemometrics and Intelligent Laboratory Systems, 2007
Predicting mycobacterial sequences promoter of protein synthesis is important in the study of pro... more Predicting mycobacterial sequences promoter of protein synthesis is important in the study of protein metabolism regulation. This goal is however considered a challenging computational biology task due to low inter-sequences homology. Consequently, a previous work based only on DNA sequence had to use a large input parameter set and multilayered feed-forward ANN architecture trained using the error-back-propagation algorithm to raise
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Papers by Alcides Pérez Bello