Search

Microsatellites were used to evaluate and compare the lineage relationships and genetic diversity of two improved cultivars of corn (Zea mays L.), seven modern native races, and eight archaeological Chimú samples (1.100-1.500 AD) of the North Peruvian coast. Electrophoresis was required to remove the PCR inhibitors from ancient DNA. Eight STR primer pairs generated amplicons from the genome of modern corn, but only five amplified ancient corn DNA. To establish the lineage relationships among samples, the coefficient of similarity of Jaccard and the technique of analysis of conglomerate with binding average were used. Thus, the pattern of genealogical and genetic relationships of the genotypes were determined. Seven out of the eight pairs of SSR primers revealed polymorphism, being 2.47 (range 2-6) the average of polymorphic alleles. The total alleles tested were 23, with 97 polymorphic bands for the modern corn, yet being monomorphic for the Chimú corn, generating an average of genetic similarity of 0.44 and 1, respectively. These results suggest the existence of inbreeding in some populations of Chimú corn of the north coast of Peru 500 to 900 years ago. Modern races exhibited higher polymorphism, due to hybridization and better assisted selection, in agreement with cytogenetic data. [ABSTRACT FROM AUTHOR]

Copyright of Médicas UIS is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de Investigación en Salud VIVE is the property of Revista de Investigacion en Salud VIVE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective. To determine the presence of Mycobacterium avium subsp. paratuberculosis (MAP) using serological, microbiological, and molecular methods, to genotype MAP isolates, and to explore factors associated to MAP-seropositive status in a buffalo herd of the province of Antioquia (Colombia). Materials and methods. The study was carried out to test fecal and serum samples from 21 asymptomatic adult buffaloes using culture and ELISA tests. Suspicious culture isolates were confirmed by MAP-IS900-PCR (IS900-PCR). The positive DNA was retested using MAP-IS900-quantative PCR (IS900-qPCR), and then, sub-typed using techniques based on the detection of mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) and multilocus short sequence repeat (MLSSR). Results. At sampling, the average age of animals was 4.7 years, 90.5% (19/21) were females and 84.2% (16/19) were pregnant. The average body condition score was 4.2 (in a 1-to-5 scale). The average milk yield was 3.5 L/day/animal. No MAP-seropositive animals were detected. One dairy buffalo cow out of the 21 buffaloes was positive by fecal culture at week 6 of incubation and then confirmed by IS900-PCR. Sub-typing analysis revealed that the MAP isolate corresponded to the INMV 3 genotype by MIRU-VNTR. Conclusions. To the best of the author's knowledge, this is the first report of MAP diagnosis and isolation in Colombian buffaloes and the first time an INMV 3 MAP-profile is found in this species the country. [ABSTRACT FROM AUTHOR]

Objectives. To analyze the cysteine-protease (CP) gene sequences of Tritrichomonas spp. reported in GenBank, and develop a phylogenetic analysis to help clarify the possibility of transmission between species. Materials and Methods. The CP sequences of Tritrichomonas spp. available in GenBank were analyzed and aligned to identify polymorphic sites. The best nucleotide substitution model was determined, and phylogenetic trees were constructed for each gene, using Trichomonas vaginalis as an outgroup. Besides, tandem sequences of each reported pathogen were constructed to build phylogenetic trees with higher branch strength. Finally, the evolutionary divergence of the tandem repeat sequences was estimated to obtain more conclusive results. Results. The phylogenetic analysis showed the relationship that may exist between porcine T. suis and bovine T. foetus. The feline and bovine T. foetus sequences were found in separate groups; however, feline T. foetus was similar to that of bovines from Namibia. The proximity of human T. foetus to bovine and porcine T. foetus was verified. Conclusions. Phylogenetic analysis of CP sequences in different species of Tritrichomonas spp., identified relationships between bovine, porcine and human Tritrichomonas, but also between some isolated feline sequences with those of bovines, suggesting a possibility of barrier crossing between species. [ABSTRACT FROM AUTHOR]

Objective. To determine Mycobacterium avium subsp. paratuberculosis (MAP) molecular diversity in environmental samples from Colombian dairy herds. Materials and methods. Environmental samples from 25 IS900-qPCR MAP-positive dairy herds were cultured by duplicate in Herrold's egg yolk medium with mycobactin J to obtain isolates. Suspicious colonies were confirmed by MAPIS900- qPCR. Positive DNA was sub-typed using mycobacterial interspersed repetitive units-variable number of tandem repeat (MIRU-VNTR) and multilocus short sequence repeats (MLSSR) techniques to analyze the genetic differences between the isolates. Results. Sub-typing revealed two different genotypes by MIRU-VNTR (INMV 2 and INMV 36). MLSSR technique was carried out to increase the discriminatory power from what was obtained by MIRU-VNTR, but no differences were observed among the recovered isolates. Conclusions. The present study represents an important approach to the knowledge on MAP epidemiological status in the study population. [ABSTRACT FROM AUTHOR]

Introduction: Hydrodynamic lubrication occurs when a sufficiently thick lubricant film is formed that prevents contact between the sliding surfaces. This physical phenomenon is characterized by a low friction coefficient that improves machine efficiency and reduces the wear of its elements. Objective: A theoretical study is carried out to determine the possibility of achieving this lubrication regime in cane mills supports. Materials and Methods: To achieve this objective, a spreadsheet is developed that provides the dependence of the minimum lubricating film thickness on the diametric clearance between the shaft and the bushing. When comparing the obtained function with the minimum permissible thickness recommended in literature, the diametric clearance interval in which hydrodynamic lubrication is achieved is obtained. It is also verified that this interval is sufficient to contain shaft and bush manufacturing tolerances. Results and Discussion: The result of carried out calculation shows that hydrodynamic lubrication can be achieved in all the tandem rolls, except for the upper one of fourth and fifth mills. Conclusions: In this way, it is concluded that it is possible to significantly improve the efficiency of the tandem of the sugar mills by making the necessary modifications to its design in such a way that a constant supply of lubricant to the contact area of the sliding surfaces is guaranteed. [ABSTRACT FROM AUTHOR]

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)