177 research outputs found

    Universidad y luchas urbanas en la Castilla bajomedieval

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    Producción CientíficaEn los siglos bajomedievales el interés social por la universidad se deja sentir en el propio transcurrir de la vida universitaria, e incluso, al menos en parte, incide en su progresiva transformación. La universidad, que aparece ya como una corporación urbana, acoge a un número creciente de estudiantes laicos, que, interesados por acceder a ciertos conocimientos útiles para su vida profesional, frecuentan las aulas para seguir cursos de derecho, retórica, aritmética, medicina u otras ciencias; el nuevo interés que estos alumnos manifiestan respecto al mundo del saber influye en la evolución de las escuelas. Paralelamente, conscientes de su integración en el medio urbano, los centros superiores de enseñanza se van haciendo eco de las necesidades e intereses del medio en el que se desarrollan, lo que, unido a su necesidad de protección material, hace que acepten la intervención, la mayor parte de las veces indirecta, de poderes ajenos a ellos mismos

    An open source Python library for environmental isotopic modelling

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    Altres ajuts: from the Balearic Island Government through the Margalida Comas postdoctoral fellowship programme (PD/036/2020).Isotopic composition modelling is a key aspect in many environmental studies. This work presents Isocompy, an open source Python library that estimates isotopic compositions through machine learning algorithms with user-defined variables. Isocompy includes dataset preprocessing, outlier detection, statistical analysis, feature selection, model validation and calibration and postprocessing. This tool has the flexibility to operate with discontinuous inputs in time and space. The automatic decision-making procedures are knitted in different stages of the algorithm, although it is possible to manually complete each step. The extensive output reports, figures and maps generated by Isocompy facilitate the comprehension of stable water isotope studies. The functionality of Isocompy is demonstrated with an application example involving the meteorological features and isotopic composition of precipitation in N Chile, which are compared with the results produced in previous studies. In essence, Isocompy offers an open source foundation for isotopic studies that ensures reproducible research in environmental fields

    Effects of the administration of 25(OH) vitamin D3 in an experimental model of chronic kidney disease in animals null for 1- Alpha-hydroxylase

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    The final step in vitamin D activation is catalyzed by 1-alpha-hydroxylase (CYP27B1). Chronic kidney disease (CKD) is characterized by low levels of both 25(OH)D3 and 1,25 (OH)2D3 provoking secondary hyperparathyroidism (2HPT). Therefore, treatments with active or native vitamin D compounds are common in CKD to restore 25(OH)D3 levels and also to decrease PTH. This study evaluates the dose of 25(OH)D3 that restores parathyroid hormone (PTH) and calcium levels in a model of CKD in CYP27B1-/- mice. Furthermore, we compare the safety and efficacy of the same dose in CYP27B1+/+ animals. The dose needed to decrease PTH levels in CYP27B1-/- mice with CKD was 50 ng/g. That dose restored blood calcium levels without modifying phosphate levels, and increased the expression of genes responsible for calcium absorption (TRPV5 and calbindinD- 28K in the kidney, TRPV6 and calbindinD-9k in the intestine). The same dose of 25(OH)D3 did not modify PTH in CYP27B1+/+ animals with CKD. Blood calcium remained normal, while phosphate increased significantly. Blood levels of 25(OH)D3 in CYP27B1-/- mice were extremely high compared to those in CYP27B1+/+ animals. CYP27B1+/+ animals with CKD showed increases in TRPV5, TRPV6, calbindinD-28K and calbindinD-9K, which were not further elevated with the treatment. Furthermore, CYP27B1+/+ animals displayed an increase in vascular calcification. We conclude that the dose of 25(OH)D3 effective in decreasing PTH levels in CYP27B1-/- mice with CKD, has a potentially toxic effect in CYP27B1+/+ animals with CKD.This work was supported by the Instituto de Salud Carlos III PS12/01770, RD12/0021/0026
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