6 research outputs found
APOBEC3G Variants and Protection against HIV-1 Infection in Burkina Faso.
No full textStudies on host factors, particularly the APOBEC3G gene, have previously found an association with AIDS progression in some populations and against some HIV-1 strains but not others. Our study had two main objectives: firstly, to screen a population from Burkina Faso for three variants of APOBEC3G previously described, and secondly to analyze the effect of these three variants and their haplotypes on HIV-1 infection with Circulating Recombinant Forms (CRFs) present in Burkina Faso. This case control study involved 708 seropositive and seronegative individuals. Genotyping was done by the TaqMan allelic discrimination method. Minor allele frequencies of rs6001417 (p<0.05), rs8177832 (P<0.05), and rs35228531 (P<0.001) were higher in seronegative subjects. The rs6001417 and rs8177832 SNPs were associated with HIV-1 infection in an additive model (P<0.01). Furthermore the SNP rs35228531 was also associated with HIV-1 infection in a dominant model (P<0.001). Odds ratio analysis of genotypes and alleles of the different APOBEC3G variants showed that there is a strong association between the minor genetic variants, genotype of the three SNPs, and HIV-1 status. Haplotype analysis demonstrated that rs6001417, rs8177832, and rs35228531 are in linkage disequilibrium. The haplotype GGT from the rs6001417, rs8177832 and rs35228531 respectively has a protective effect OR = 0.54 [0.43-0.68] with P<0.001. There was also associations between the haplotypes GGC OR = 1.6 [1.1;-2.3] P<0.05, and CGC OR = 5.21 [2.4-11.3] P<0.001, which increase the risk of infection by HIV-1 from almost two (2) to five (5) fold. This study demonstrates an association of rs6001417, rs8177832, and rs35228531 of APOBEC3G with HIV-1 infection in a population from Burkina Faso
Distribution of the cases and controls haplotypes.
No full text<p>Distribution of the cases and controls haplotypes.</p
Haploview APOBEC3G linkage disequilibrium plots for case and controls.
No full text<p>The figures are oriented 5’ to 3’, right to left, relative to the gene orientation on the minus strand. Fig 1a represents the LD plot of the case pairwise D’ between markers, and Fig 1b shows the LD plot of the control pairwise D’ between markers. Strong LD is indicated by red, while pink indicate uninformative values. LD blocks were created with the default algorithm in the Haploview software (version 4.1) that creates 95% confidence bounds. D’ was considered strong where 95% of the comparisons made are informative.</p
Modelado y simulación de sistemas fotovoltaicos bajo condiciones de sombreado parcial
No full textgraficas, tablasThis thesis introduces a methodology for modeling commercial photovoltaic panels at the cell
level operating under partial shading conditions. In the first part, a review of the literature
is presented, focusing on the proper representation of the current-voltage characteristics in
both forward and reverse bias, the mathematical formulation, the circuit model, and the
estimation of parameters for photovoltaic cells.
In the second part, the single diode model (SDM), the direct-reverse model (DRM), and
Bishop’s model are introduced, emphasizing their current-voltage relationship, mathematical
formulation, circuit model, and parameter requirements.
In the third part of the thesis, a procedure to obtain I-V curves in panel terminals without
the need for any physical intervention is detailed. This procedure is necessary to compare
the behavior of the three models analyzed in both quadrants. The procedure requires a panel
without a bypass diode and measurement equipment capable of acquiring current, voltage,
temperature, and irradiation.
After considering the evaluation of some metrics such as root mean square error (RMSE)
and mean absolute percentage error (MAPE), Bishop’s model is selected for use in the
methodology.
In the fourth part, a methodology to estimate the parameters of Bishop’s model is proposed, which formulates the estimation of the parameters as an optimization problem. The metho-
dology uses a genetic algorithm, and it is validated using information from two commercial
panels. The curve reconstructions for each technology are evaluated using metrics such as
RMSE and MAPE to assess the accuracy of the models (Texto tomado de la fuente)Esta tesis presenta una metodología de modelado de paneles fotovoltaicos comerciales a nivel
de celda operando bajo condiciones de sombreado parcial. En la primera parte se realiza
una revisión de la literatura sobre la representación de celdas fotovoltaicas, en la que se
consideran características importantes como la formulación matemática, el modelo circuital,
la representación apropiada del comportamiento en modo directo e inverso y la estimación
de parámetros.
En la segunda parte, se exponen algunos de los modelos m ́as utilizados en la literatura para
el modelado de celdas fotovoltaicas, Modelo de un solo diodo (SDM), Modelo DRM y el
modelo de Bishop, prestando especial atención a la relación corriente-voltaje, la formulación
matemática, el modelo circuital y los parámetros necesarios para su evaluación. Para modelar
los paneles a nivel de celda, la tercera parte se enfoca en detallar un procedimiento para
obtener las curvas I-V en terminales de un panel, sin necesidad de ninguna intervención
física. Para lo se requiere un panel sin diodo de bypass, información del panel obtenida al
sombrear el panel y algunos equipos de medida que permitan adquirir corriente, voltaje,
temperatura e irradiación.
En la tercera parte de la tesis se detalla un procedimiento para obtener curvas I-V en terminales del panel sin necesidad de intervención física alguna. Este procedimiento es necesario
para comparar el comportamiento de los tres modelos analizados en ambos cuadrantes. El
procedimiento requiere un panel sin diodo de derivación y un equipo de medición capaz de
adquirir corriente, voltaje, temperatura e irradiación.
Después de considerar la evaluación de algunas métricas como el error cuadrático medio
(RMSE) y el error porcentual absoluto medio (MAPE), se selecciona el modelo de Bishop
para su uso en la metodología.
En la cuarta parte, se propone una metodología para estimar los parámetros del modelo de
Bishop, formulando el problema de estimación de parámetros como un problema de optimización. La metodología utiliza un algoritmo genético y se valida con información de dos
paneles comerciales. Las reconstrucciones de curvas para cada tecnología se evalúan utilizando métricas como RMSE y MAPE para evaluar la precisión de los modelos.DoctoradoDoctor en IngenieríaEléctrica, Electrónica, Automatización Y Telecomunicaciones.Sede Manizale
