Ellagic Acid as Green Corrosion Inhibitor: a Necessary Validation

Corrosion of metals is an unavoidable but controllable process. Among techniques developed to slow down or prevent metal deterioration the addition of small amount of inhibitors directly in the corrosive environment is a quite common strategy. In particular, among organic compounds effectively used as adsorption inhibitors (thanks to N, O and/or S atoms that act as anchoring groups for metal surface) only a few percentage belongs to the so called \u201cgreen inhibitor\u201d class. In this field most of the studies employ plant extracts being rich in phytochemical constituents considered to be potential eco-friendly corrosion inhibitors. However, the often extraordinary complexity of crude extracts makes difficult the rationalization of the inhibition mechanism. So, from a purely academic point of view, the study of pure compounds is often encouraged. Among potential green inhibitors our attention has been focused on ellagic acid (EA) that can be obtained by hydrolysis of ellagitannin contained in peels of pomegranate. Ellagic acid is a polyphenol having four phenolic and two lactone groups that should act like two and one couples of equivalent sites, respectively, due to the C2h molecular symmetry. Up to know the corrosion inhibition properties of EA was only marginally studied in literature, both theoretically and experimentally. However some reported results need to be validated because of discrepancies concerning some fundamental chemical physical features of the target acid, like i) solubility in pure water (9 mg/dm3 versus 1.2 g/dm3) and ii) pKa values for the two acid dissociation processes. For this purposes, using UV-Vis absorption spectroscopy, a mainly-aqueous medium was selected to assure homogeneity of the EA-based solution; after that the corrosion inhibition properties of ellagic acid toward mild steel was studied by weight loss measurements (according to ASTM G1 standard practice) and by electrochemical tests. Preliminary results performed in 1% v/v MeOH/H2O mixture with HCl 0.05 M point to potentially interesting inhibition effect even working with 1.0 1910\u20135 M EA (i.e., 3 mg/dm3)

Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes

Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA3 ) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO 3 staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent

Genetic footprints of iberian cattle in America 500 years after the arrival of Columbus.

American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, andmay have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. Methodology/Principal Findings: We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. Conclusions/Significance: Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus

Background: American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, andmay have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. Methodology/Principal Findings: We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. Conclusions/Significance: Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental condition

Marcadores moleculares asociados al veteado de la carne en bovinos criollos uruguayos

The Uruguayan Creole cattle genetic reserve, located in the department of Rocha, has a high level of genetic variation, as previous studies using polymorphic markers showed. Cattle from this reserve were taken to commercial farms in the North of Uruguay during the 60'. These animals where used in crosses with commercial breeds (Aberdeen Angus, Hereford, Caracú) and zebu (Bos indicus) cattle for meat production. We analyzed a sample of Creole cattle from Rocha and from two crossbred populations from Northern Uruguay (Rivera and Cerro Largo) using three molecular markers associated with marbling: diacyl-glicerol acyl transferase (DGAT1), thyroglobulin (TG) and leptin (LEP). We describe a novel and cost-effective genotyping method based on TETRA-ARMS PCR for LEP polymorphism. The Creole cattle reserve showed higher frequencies of alleles and genotypes associated with low marbling scores in all markers. Both crossbred populations showed the same trend for DGAT1, but higher frequencies for alleles and genotypes associated with higher marbling in TG and LEP. Genetic diversity indexes were low to moderate (minimum He= 0.000 for DGAT1 in Rivera crossbred population; maximum He= 0.632 for TG in Cerro Largo crossbred population). No significant departures from the expected values were detected according to F IS and Hardy-Weinberg tests, except for one case (TG in Cerro Largo population). F ST values showed the high genetic similarities between both crossbred populations and their differentiation from the purebred Uruguayan Creole reserve. Genetic introgression of commercial breeds, plus selection objectives tending to increase productivity, had affected the frequencies of the markers analyzed in the crossbred populations. On the other hand, reproductive isolation, absence of artificial selection and the incidence of genetic drift and natural selection had modelled the population para- meters of the Uruguayan Creole cattle reserve.En Uruguay existe una reserva genética de bovinos Criollos ubicada en el Departamento de Rocha. Estudios previos basados en marcadores moleculares altamente polimórficos mostraron que dicha población presenta una alta diversidad ge- nética. En la década del 60 se produjo una migra- ción de bovinos Criollos de la reserva a estable- cimientos ganaderos del norte del país. Este gana- do fue utilizado en cruzamientos comerciales con las razas Aberdeen Angus, Hereford, Caracú y cebuinas, estando sus productos introducidos en el mercado cárnico uruguayo. Se presentan datos de la caracterización genética de la reserva y de dos poblaciones cruza (Rivera y Cerro Largo) para tres marcadores moleculares asociados al veteado de la carne: diacilglicerol acetil-transferasa (DGAT1), tiroglobulina (TG) y leptina (LEP), así como una metodología de genotipado novedosa y eficaz para el polimorfismo del gen LEP mediante TETRA-ARMS PCR. La reserva de Criollos mostró una predominancia de los alelos y genotipos aso- ciados a carne de bajo tenor graso en todos los marcadores. Las dos poblaciones cruza de Criollo con razas comerciales mostraron la misma ten- dencia para el gen DGAT1, pero mayores frecuen- cias de los alelos y genotipos que generan un incremento del veteado para TG y LEP. Los índices de diversidad genética resultaron de bajos a moderados (He mínima= 0,000 para DGAT1 en la población cruza de Rivera; He máxima= 0,632 para TG en la población cruza de Cerro Largo). No se observan diferencias significativas de los valores esperados para los parámetros poblacionales, según índices F IS y prueba de equilibrio Hardy- Weinberg, salvo en un caso (TG en el rodeo de Cerro Largo). Los valores de F ST muestran la similitud genética entre las dos poblaciones cruza y su diferenciación con respecto a la reserva de Criollos Uruguayos puros. La introgresión de ra- zas comerciales y los objetivos de selección en pos de una mayor productividad afectaron las frecuencias de los marcadores analizados en los rodeos cruza. Por otro lado, el aislamiento reproductivo, la ausencia de selección artificial y la incidencia de la deriva y la selección natural han moldeado los parámetros genéticos de la reserva de Criollos Uruguayos

Diversidade e relações genéticas em populações bovinas da Ibero-América - resultados preliminares.

A presumível origem Ibérica das raças bovinas Crioulas está presentemente a ser estudada num trabalho que envolve uma amostragem de mais de 3300 animais de 85 raças, utilizando um painel comum de 22 marcadores microssatélites. Adicionalmente, num número de raças mais reduzido, está a ser estudada a variabilidade genética em marcadores do DNA mitocondrial e do cromossoma Y. Os resultados preliminares obtidos até ao momento indicam uma elevada diversidade genética nas raças bovinas Crioulas, e a proximidade de algumas delas com as raças Ibéricas. Contudo, noutras raças Crioulas observa-se alguma influência de raças britânicas e zebuínas. Este trabalho demonstra os benefícios resultantes das sinergias estabelecidas pelos diferentes grupos, sendo de justiça destacar o papel fundamental desempenhado pela rede CYTED (actual Red COMBIAND) na interligação e criação de vínculos de colaboração entre os vários grupos de investigaçã

Genetic characterization of Latin-American Creole cattle using microsatellite markers

Genetic diversity in and relationships among 26 Creole cattle breeds from 10 American countries were assessed using 19 microsatellites. Heterozygosities, F-statistics estimates, genetic distances, multivariate analyses and assignment tests were performed. The levels of within-breed diversity detected in Creole cattle were considerable and higher than those previously reported for European breeds, but similar to those found in other Latin American breeds. Differences among breeds accounted for 8.4% of the total genetic variability. Most breeds clustered separately when the number of pre-defined populations was 21 (the most probable K value), with the exception of some closely related breeds that shared the same cluster and others that were admixed. Despite the high genetic diversity detected, significant inbreeding was also observed within some breeds, and heterozygote excess was detected in others. These results indicate that Creoles represent important reservoirs of cattle genetic diversity and that appropriate conservation measures should be implemented for these native breeds in order to minimize inbreeding and uncontrolled crossbreeding. © 2011 Stichting International Foundation for Animal Genetics