Plazos de pago y cobro dinámicos aplicados a una relación comercial entre empresas

El presente trabajo de Tesis tiene como objetivo principal el de demostrar que la implementación de una metodología de Plazos de Pago Dinámicos resulta beneficiosa para un sistema compuesto por un conjunto formado por una empresa proveedora y una empresa cliente sin importar el tipo de insumo o servicio que se comercie dentro del mismo

Genome-wide analysis of codon usage bias in Bovine Coronavirus

Background Bovine coronavirus (BCoV) belong to the genus Betacoronavirus of the family Coronaviridae. BCoV are widespread around the world and cause enteric or respiratory infections among cattle, leading to important economic losses to the beef and dairy industry worldwide. To study the relation of codon usage among viruses and their hosts is essential to understand host-pathogen interaction, evasion from host's immune system and evolution. Methods We performed a comprehensive analysis of codon usage and composition of BCoV. Results The global codon usage among BCoV strains is similar. Significant differences of codon preferences in BCoV genes in relation to codon usage of Bos taurus host genes were found. Most of the highly frequent codons are U-ending. G + C compositional constraint and dinucleotide composition also plays a role in the overall pattern of BCoV codon usage. Conclusions The results of these studies revealed that mutational bias is a leading force shaping codon usage in this virus. Additionally, relative dinucleotide frequencies, geographical distribution, and evolutionary processes also influenced the codon usage pattern

A comprehensive analysis of genome composition and codon usage patterns of emerging coronaviruses

An outbreak of atypical pneumonia caused by a novel Betacoronavirus (βCoV), named SARS-CoV-2 has been declared a public health emergency of international concern by the World Health Organization. In order to gain insight into the emergence, evolution and adaptation of SARS-CoV-2 viruses, a comprehensive analysis of genome composition and codon usage of βCoV circulating in China was performed. A biased nucleotide composition was found for SARS-CoV-2 genome. This bias in genomic composition is reflected in its codon and amino acid usage patterns. The overall codon usage in SARS-CoV-2 is similar among themselves and slightly biased. Most of the highly frequent codons are A- and U-ending, which strongly suggests that mutational bias is the main force shaping codon usage in this virus. Significant differences in relative synonymous codon usage frequencies among SARS-CoV-2 and human cells were found. These differences are due to codon usage preferences.ANII; CSI

Phylogenetic analyses of rotavirus a from cattle in uruguay reveal the circulation of common and uncommon genotypes and suggest interspecies transmission

Uruguay is one of the main exporters of beef and dairy products, and cattle production is one of the main economic sectors in this country. Rotavirus A (RVA) is the main pathogen associated with neonatal calf diarrhea (NCD), a syndrome that leads to significant economic losses to the livestock industry. The aims of this study are to determine the frequency of RVA infections, and to analyze the genetic diversity of RVA strains in calves in Uruguay. A total of 833 samples from dairy and beef calves were analyzed through RT-qPCR and sequencing. RVA was detected in 57.0% of the samples. The frequency of detection was significantly higher in dairy (59.5%) than beef (28.4%) calves (p < 0.001), while it did not differ significantly among calves born in herds that were vaccinated (64.0%) or not vaccinated (66.7%) against NCD. The frequency of RVA detection and the viral load were significantly higher in samples from diarrheic (72.1%, 7.99 log10 genome copies/mL of feces) than non-diarrheic (59.9%, 7.35 log10 genome copies/mL of feces) calves (p < 0.005 and p = 0.007, respectively). The observed G-types (VP7) were G6 (77.6%), G10 (20.7%), and G24 (1.7%), while the P-types were P[5] (28.4%), P[11] (70.7%), and P[33] (0.9%). The G-type and P-type combinations were G6P[11] (40.4%), G6P[5] (38.6%), G10P[11] (19.3%), and the uncommon genotype G24P[33] (1.8%). VP6 and NSP1-5 genotyping were performed to better characterize some strains. The phylogenetic analyses suggested interspecies transmission, including transmission between animals and humans.Fil: Castells, Matías. Universidad de la República; UruguayFil: Caffarena, Rubén Darío. Universidad de la República; UruguayFil: Casaux, María Laura. Universidad de la República; UruguayFil: Schild, Carlos. Universidad de la República; UruguayFil: Miño, Samue. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Castells, Felipe. Universidad de la República; UruguayFil: Castells, Daniel. Universidad de la República; UruguayFil: Victoria, Matías. Universidad de la República; UruguayFil: Riet Correa, Franklin. Universidad de la República; UruguayFil: Giannitti, Federico. Universidad de la República; UruguayFil: Parreño, Gladys Viviana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; ArgentinaFil: Colina, Rodney. Universidad de la República; Urugua

The First Case of Bovine Astrovirus-Associated Encephalitis in the Southern Hemisphere (Uruguay), Uncovers Evidence of Viral Introduction to the Americas From Europe.

Astrovirus species members of the Mamastrovirus genus (family Astroviridae) have been increasingly recognized as neuroinvasive pathogens in various mammals, including humans, mink, cattle, sheep, and pigs. While cases of astrovirus-associated encephalitis have been reported in North America, Europe, and Asia, their presence has never been documented in the Southern hemisphere. This paper describes a case of astrovirus-associated encephalitis in cattle in Uruguay that broadens the geographic distribution and genetic diversity of neuroinvasive astroviruses and provides phylogeographic evidence of viral introduction to the Americas from Europe. A 22-month-old Holstein steer from a farm in Colonia Department, Uruguay developed progressive neurological signs over a 3-days period before dying. Histopathological examination of the brain and proximal cervical spinal cord revealed disseminated, moderate to severe lymphocytic, histiocytic, and plasmacytic poliomeningoencephalomyelitis with neuronal necrosis. A Mamastrovirus strain in the CH13/NeuroS1 clade, that we called bovine astrovirus (BoAstV)-Neuro-Uy, was identified by reverse transcriptase PCR followed by nearly complete genome sequencing. Additionally, BoAstV was detected intralesionally in the brain by chromogenic RNA in situ hybridization within neuronal perikarya, axons and dendrites. Phylogenetic analysis of BoAstV-Neuro-Uy revealed a close relationship to neurotropic BoAstVs within the Virginia/Human-Mink-Ovine clade, which contains a growing cadre of neuroinvasive astroviruses. Analyzing the complete coding region of neuroinvasive BoAstVs sequences available in GenBank, we estimated an evolutionary rate of 4.27 × 10-4 (95% HPD 2.19-6.46 × 10-4) nucleotide substitutions/site/year. Phylogeographic analysis suggests that the common viral ancestor circulated in Europe between 1794-1940, and was introduced in Uruguay between 1849-1967, to later spread to North America and Japan

Evidence of increasing diversification of emerging Severe Acute Respiratory Syndrome Coronavirus 2 strains

On 30th January 2020, an outbreak of atypical pneumonia caused by a novelbetacoronavirus, named severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2), was declared a public health emergency of international concern bythe World Health Organization. For this reason, a detailed evolutionary analysis ofSARS‐CoV‐2 strains currently circulating in different geographic regions of theworld was performed. A compositional analysis as well as a Bayesian coalescentanalysis of complete genome sequences of SARS‐CoV‐2 strains recently isolated inEurope, North America, South America, and Asia was performed. The results ofthese studies revealed a diversification of SARS‐CoV‐2 strains in three differentgenetic clades. Co‐circulation of different clades in different countries, as well asdifferent genetic lineages within different clades were observed. The time of themost recent common ancestor was established to be around 1st November 2019.A mean rate of evolution of 6.57 × 10−4substitutions per site per year was found.A significant migration rate per genetic lineage per year from Europe to SouthAmerica was also observed. The results of these studies revealed an increasingdiversification of SARS‐CoV‐2 strains. High evolutionary rates and fast populationgrowth characterizes the population dynamics of SARS‐CoV‐2 strains

DESARROLLO DE MÉTODOS CROMATOGRÁFICOS QUIRALES PARA EL ESTUDIO Y CUANTIFICACIÓN DE PLAGUICIDAS EN MATRICES AMBIENTALES

Aproximadamente un 30% de los plaguicidas son moléculas quirales de 2^n enantiómeros (n = número de carbonos asimétricos). Algunos de estos se comercializan enantoméricamente puros o como formulaciones enantioméricamente enriquecidas en el enantiómero con mayor actividad plaguicida con el fin de emplear productos con actividades específicas mayores, lo que conduce a minimizar la cantidad de productos químicos liberados al ambiente. Los métodos cromatográficos y, en menor medida, los electroforéticos son las técnicas mas utilizadas para la separación y análisis de enantiómeros. Las columnas cromatográficas constituidas por fases estacionarias quirales (FEQs) basadas en polisacáridos han sido las más extensamente empleadas para la enantioresolución de plaguicidas quirales por cromatografía de líquidos (HPLC) y cromatografía de fluidos supercríticos (SFC). En la actualidad, el fenil-carbamato o sus ésteres de polisacárido, ya sea adsorbido o inmovilizado sobre la sílice, puede utilizarse para la separación de enantiómeros en fase normal (NP), fase inversa (RP), polar-orgánico (PO) y más recientemente con cromatografía líquida de interacción hidrofílica (HILIC). El empleo de estas columnas en los modos PO y RP significa no solo mayor compatibilidad analito/solvente, sino que permite extender la aplicabilidad de algunas columnas, la posibilidad de reducir los tiempos de análisis y, por ende, aumentar la productividad, emplear solventes ambientalmente más amigables, y el potencial incremento en la especificidad del análisis determinativo. El objetivo general de este estudio persigue desarrollar métodos de separación y análisis enantiomérico de compuestos quirales por HPLC utilizando columnas de derivados de polisacáridos y aplicar estos métodos a la determinación de plaguicidas en matrices ambientales. Más específicamente, el trabajo experimental consistirá en los siguientes puntos: - Determinar enantioselectividad y enantioresolución de plaguicidas por HPLC empleando columnas quirales de derivados de polímeros naturales, operadas preferentemente en modo RP y PO. - Estudiar la influencia de las distintas variables experimentales (solventes, pH, fuerza iónica, tipo y cantidad de aditivos y temperatura) sobre la retención y la enantioseparación. Optimizar la enantioresolución de los plaguicidas. - Estudiar el(los) mecanismo(s) involucrado(s) en el reconocimiento quiral de estos plaguicidas. - Analizar la composición enatiomérica de plaguicidas quirales en muestras reales. En el caso de requerirse, emplear herramientas quimiométricas para aquellos perfiles cromatográficos parcialmente resueltos. - Evaluar cinéticamente la degradación y/o interconversión de los enantiómeros y posibles metabolitos principales en suelo y aguas naturales bajo condiciones de laboratorio

Seudoartrosis después de una osteotomía en chevron: incidencia, tratamiento, seguimiento y evolución

Introducción: El hallux valgus es el trastorno más común del primer dedo del pie. Provoca dolor, discapacidad funcional y altera los patrones de la marcha. Las deformidades leves o moderadas se han corregido con osteotomías distales del primer metatarsiano, como la osteotomía en chevron, un procedimiento seguro, pero no exento de complicaciones. Los objetivos de este estudio fueron determinar la incidencia de seudoartrosis por dicha osteotomía y comunicar nuestro método terapéutico, el seguimiento y la evolución. Materiales y Métodos: Se realizó un estudio multicéntrico, retrospectivo que incluyó a pacientes operados entre 2009 y 2018. Se evaluaron 1156 osteotomías en chevron como tratamiento del hallux valgus leve o moderado en 1017 pacientes (rango etario 16-83 años; promedio 57.5) realizadas por 4 cirujanos experimentados. El criterio de inclusión fue que el paciente contara con estudios por imágenes compatibles con seudoartrosis a los 6 meses de la cirugía. Resultados: Se evaluó a 5 pacientes con diagnóstico de seudoartrosis después de una osteotomía en chevron para tratar el hallux valgus. Los puntajes promedio de la AOFAS fueron 51 antes del tratamiento del hallux valgus y 87,8 después del tratamiento de la seudoartrosis. Conclusiones: La incidencia de seudoartrosis fue del 0,4% en el posoperatorio alejado. Nuestro abordaje y el tratamiento de la seudoartrosis lograron una excelente mejoría clínica y funcional en todos los pacientes operados

Recurrent dissemination of SARS-CoV-2 through the Uruguayan–Brazilian border

Uruguay is one of the few countries in the Americas that successfully contained the coronavirus disease 19 (COVID-19) epidemic during the first half of 2020. Nevertheless, the intensive human mobility across the dry border with Brazil is a major challenge for public health authorities. We aimed to investigate the origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains detected in Uruguayan localities bordering Brazil as well as to measure the viral flux across this ∼1,100 km uninterrupted dry frontier. Using complete SARS-CoV-2 genomes from the Uruguayan–Brazilian bordering region and phylogeographic analyses, we inferred the virus dissemination frequency between Brazil and Uruguay and characterized local outbreak dynamics during the first months (May–July) of the pandemic. Phylogenetic analyses revealed multiple introductions of SARS-CoV-2 Brazilian lineages B.1.1.28 and B.1.1.33 into Uruguayan localities at the bordering region. The most probable sources of viral strains introduced to Uruguay were the Southeast Brazilian region and the state of Rio Grande do Sul. Some of the viral strains introduced in Uruguayan border localities between early May and mid-July were able to locally spread and originated the first outbreaks detected outside the metropolitan region. The viral lineages responsible for Uruguayan urban outbreaks were defined by a set of between four and 11 mutations (synonymous and non-synonymous) with respect to the ancestral B.1.1.28 and B.1.1.33 viruses that arose in Brazil, supporting the notion of a rapid genetic differentiation between SARS-CoV-2 subpopulations spreading in South America. Although Uruguayan borders have remained essentially closed to non-Uruguayan citizens, the inevitable flow of people across the dry border with Brazil allowed the repeated entry of the virus into Uruguay and the subsequent emergence of local outbreaks in Uruguayan border localities. Implementation of coordinated bi-national surveillance systems is crucial to achieve an efficient control of the SARS-CoV-2 spread across this kind of highly permeable borderland regions around the world