Association of vitamin D receptor gene variants with polycystic ovary syndrome: A case control study

Background: Vitamin D and insulin play an important role in susceptibility to polycystic ovary syndrome (PCOS), and therefore vitamin D receptor (VDR), parathyroid hormone (PTH), and insulin receptor (INSR) gene variants might be involved in the pathogenesis of PCOS. Objective: The present study was designed to investigate the possible associations between polymorphisms in VDR, PTH, and INSR genes and the risk of PCOS. Materials and Methods: VDR, PTH, and INSR gene variants were genotyped in 35 women with PCOS and 35 controls using Polymerase chain reaction – Restriction fragment length polymorphism method. Furthermore, serum levels of glucose and insulin were measured in all participants. Results: No significant differences were observed for the VDR FokI, VDR Tru9I, VDR TaqI,, PTH DraII, INSR NsiI, and INSR PmlI gene polymorphisms between the women with PCOS and controls. However, after adjustment for confounding factors, the VDR BsmI “Bb” genotype and the VDR ApaI "Aa" genotype were significantly under transmitted to the patients (p= 0.016; OR= 0.250; 95% CI= 0.081-0.769, and p= 0.017; OR= 0.260; 95% CI= 0.086-0.788, respectively). Furthermore, in the women with PCOS, insulin levels were lower in the participants with the INSR NsiI "NN" genotype compared with those with the "Nn + nn" genotypes (P= 0.045). Conclusion: The results showed an association between the VDR gene BsmI and ApaI polymorphisms and PCOS risk. These data also indicated that the INSR "NN" genotype was a marker of decreased insulin in women with PCOS. Our findings, however, do not lend support to the hypothesis that PTH gene DraII variant plays a role in susceptibility to PCOS.

Impacto de la biología en los modelos de gestión y control organizacional

Desde el inicio de las organizaciones han existido modelos de control rígidos como los sistemas mecanicistas y formales en donde la perspectiva racional sobresale y no se tienen en cuenta los aspectos humanos en el diseño de los sistemas. Estos modelos de control rígidos, estandarizados y centralizados suponen un problema para el adecuado desarrollo estratégico y operativo de las organizaciones. Sin embargo, desde los sistemas biológicos se pueden observar aportes de autores que destacan la ausencia de control y su consecuente funcionamiento armónico a través de propiedades como la auto-organización y la emergencia. De esta forma, este artículo de revisión tiene como objetivo identificar las aproximaciones teóricas que se han realizado en torno a los principales aportes que los modelos biológicos han hecho a la gestión administrativa y específicamente al control organizacional mediante el análisis de la producción bibliográfica realizada en los últimos 10 años.

A second order control-volume finite-element least-squares strategy for simulating diffusion in strongly anisotropic media

An unstructured mesh �nite volume discretisation method for simulating di�usion in anisotropic media in two-dimensional space is discussed. This technique is considered as an extension of the fully implicit hybrid control-volume �nite-element method and it retains the local continuity of the ux at the control volume faces. A least squares function recon- struction technique together with a new ux decomposition strategy is used to obtain an accurate ux approximation at the control volume face, ensuring that the overall accuracy of the spatial discretisation maintains second order. This paper highlights that the new technique coincides with the traditional shape function technique when the correction term is neglected and that it signi�cantly increases the accuracy of the previous linear scheme on coarse meshes when applied to media that exhibit very strong to extreme anisotropy ratios. It is concluded that the method can be used on both regular and irregular meshes, and appears independent of the mesh quality.