Ensenada Center for Scientific Research and Higher Education

About: Ensenada Center for Scientific Research and Higher Education is a facility organization based out in Ensenada, Mexico. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 1934 authors who have published 3733 publications receiving 63115 citations.

The effect of substituting fishmeal with poultry by‐product meal in diets for Totoaba macdonaldi juveniles

Abstract: Four diets were formulated to evaluate the partial to total substitution of fishmeal with poultry by-product meal (PBM) (0, 33, 67 and 100PBM) in diets for totoaba juveniles (Totoaba macdonaldi). Amino acid profiles from diets and fatty acid content in diets and muscle tissue were used to assess the fish performance using PBM as fishmeal replacement. Stable isotopes of nitrogen (δ15N) were measured in muscle and liver tissue to quantify the retention of each protein source. At the end of the experimental period, the fish fed the 67PBM diet had a significantly higher growth gain increase compared to the other treatments (almost 2000% over an 86 days period; TGC of 1.06). The total replacement of fishmeal with PBM led to low growth gain increase (ca. 220% over 72 days; TGC of 0.52) and increased mortality. Both fish performance and tissues' fatty acid composition suggest that the 100PBM diet was deficient in essential fatty acids. An isotope-mixing model applied to isotope ratios of muscle and liver tissues of fish fed the 67PBM tissues indicated that PBM was retained into muscle and liver tissue in a higher proportion than its level of inclusion in the diet. We conclude that PBM is a good source of nutrients for totoaba juveniles when used in up to 67% fishmeal replacement level in diets containing 52% protein leading to adequate growth rate and survival.

Differential evolution algorithm applied to sidelobe level reduction on a planar array

Abstract: In this paper, differential evolution (DE), one of the youngest paradigms in evolutionary computation, is applied to the process of synthesizing a planar array factor focused on sidelobe-level reduction. Sidelobe level is a critical array factor parameter in the task of reducing background noise and interference in the most recent Wireless Communications Systems. Minimization of sidelobe level involves nonlinear and non-convex dependence between array factor and its elements parameters becoming a highly complex problem. However, DE has proven to be a fast and efficient algorithm for complex real-valued problems. Subsequently, a binary-coded genetic algorithm is proposed for the synthesis of planar arrays. Numerical results show a promising performance of DE reducing noticeably the sidelobe level generated by a uniform planar array.

Beneficial effects of dark chocolate on exercise capacity in sedentary subjects: underlying mechanisms. A double blind, randomized, placebo controlled trial.

Abstract: In heart failure patients the consumption of (-)-epicatechin ((-)-Epi)-rich cocoa can restore skeletal muscle (SkM) mitochondrial structure and decrease biomarkers of oxidative stress. However, nothing is known about its effects on exercise capacity and underlying mechanisms in normal, sedentary subjects. Twenty normal, sedentary subjects (∼50 years old) were randomized to placebo or dark chocolate (DC) groups and consumed 20 g of the products for 3 months. Subjects underwent before and after treatment, bicycle ergometry to assess VO2 max and work, SkM biopsy to assess changes in mitochondrial density, function and oxidative stress and blood sampling to assess metabolic endpoints. Seventeen subjects completed the trial. In the DC group (n = 9), VO2 max increased (17% increase, p = 0.056) as well as maximum work (watts) achieved (p = 0.026) with no changes with placebo (n = 8). The DC group evidenced increases in HDL levels (p = 0.005) and decreased triglycerides (p = 0.07). With DC, SkM evidenced significant increases in protein levels for LKB1, AMPK and PGC1α and in their active forms (phosphorylated AMPK and LKB1) as well as in citrate synthase activity while no changes were observed in mitochondrial density. With DC, significant increases in SkM reduced glutathione levels and decreases in protein carbonylation were observed. Improvements in maximum work achieved and VO2 max may be due to DC activation of upstream control systems and enhancement of SkM mitochondria efficiency. Larger clinical studies are warranted to confirm these observations.

Molecular identification of pathogenic and nonpathogenic strains of Vibrio harveyi using PCR and RAPD

Abstract: Fifteen environmental samples of Vibrio spp. isolated from healthy and diseased shrimps were tested for pathogenicity to juvenile shrimps. Two isolates, strains Z2 and Z3, were observed to be pathogenic, causing 100% mortality of the target host compared to the control strain Vibrio harveyi ATCC 14126. Environmental and type strains were subjected to molecular characterization by restriction fragment length polymorphism (RFLP) and PCR using primers targeted to different virulence, transcriptional regulator, or quorum sensing genes from V. harveyi. Primers designed for luxN were specific and identified all the environmental strains as V. harveyi. The random amplified polymorphic DNA (RAPD) method was used to differentiate between pathogenic and nonpathogenic strains of V. harveyi. These methodologies allowed us to detect and distinguish strains virulent and avirulent to juvenile shrimp.