University of Córdoba (Spain)

About: University of Córdoba (Spain) is a education organization based out in Cordova, Spain. It is known for research contribution in the topics: Population & Catalysis. The organization has 12006 authors who have published 22998 publications receiving 537842 citations. The organization is also known as: University of Córdoba (Spain) & Universidad de Córdoba.

Novel expression of resistin in rat testis: functional role and regulation by nutritional status and hormonal factors.

Abstract: Resistin, a recently cloned adipose-secreted factor, is primarily involved in the modulation of insulin sensitivity and adipocyte differentiation. However, additional metabolic or endocrine functions of this molecule remain largely unexplored. In this study, a series of experiments were undertaken to explore the potential expression, regulation and functional role of this novel adipocytokine in rat testis. Resistin gene expression was demonstrated in rat testis throughout postnatal development, with maximum mRNA levels in adult specimens. At this age, resistin peptide was immunodetected in interstitial Leydig cells and Sertoli cells within seminiferous tubules. Testicular expression of resistin was under hormonal regulation of pituitary gonadotropins and showed stage-specificity, with peak expression values at stages II-VI of the seminiferous epithelial cycle. In addition, testicular resistin mRNA was down-regulated by the selective agonist of PPARγ, rosiglitazone, in vivo and in vitro. Similarly, fasting and central administration of the adipocyte-derived factor, leptin, evoked a significant reduction in testicular resistin mRNA levels, whereas they remained unaltered in a model of diet-induced obesity. From a functional standpoint, resistin, in a dose-dependent manner, significantly increased both basal and choriogonadotropin-stimulated testosterone secretion in vitro. Overall, our present results provide the first evidence for the expression, regulation and functional role of resistin in rat testis. These data underscore a reproductive facet of this recently cloned molecule, which may operate as a novel endocrine integrator linking energy homeostasis and reproduction.

Promoter DNA hypermethylation and gene repression in undifferentiated Arabidopsis cells.

Abstract: Maintaining and acquiring the pluripotent cell state in plants is critical to tissue regeneration and vegetative multiplication. Histone-based epigenetic mechanisms are important for regulating this undifferentiated state. Here we report the use of genetic and pharmacological experimental approaches to show that Arabidopsis cell suspensions and calluses specifically repress some genes as a result of promoter DNA hypermethylation. We found that promoters of the MAPK12, GSTU10 and BXL1 genes become hypermethylated in callus cells and that hypermethylation also affects the TTG1, GSTF5, SUVH8, fimbrin and CCD7 genes in cell suspensions. Promoter hypermethylation in undifferentiated cells was associated with histone hypoacetylation and primarily occurred at CpG sites. Accordingly, we found that the process specifically depends on MET1 and DRM2 methyltransferases, as demonstrated with DNA methyltransferase mutants. Our results suggest that promoter DNA methylation may be another important epigenetic mechanism for the establishment and/or maintenance of the undifferentiated state in plant cells.

Olive Oil Quality Decreases with Nitrogen Over-fertilization

Abstract: Mature 'Picual' olive (Olea europaea L.) trees growing in two different localities of Cordoba and Jaen provinces, southern Spain, were subjected to annual applications of 0, 0.12, 0.25, 0.50, or 1.0 kg N/tree in the Cordoba's experiment, and to 0 or 1.5 kg N/tree in the Jaen's experiment. Nitrogen was applied 50% to the soil and 50% through foliar application in Cordoba, and 100% to the soil in Jaen. Three years after the initiation of treatments, when the trees showed differences among them in nitrogen content, fruit were sampled at maturity from each experimental tree during six consecutive seasons to determine the effect of nitrogen fertilization on olive oil quality. Tree nitrogen status was always above the threshold limit for defi ciency even in control trees, indicating that most treatments caused nitrogen over fertilization. Nitrogen in excess was accumulated in fruit and, consequently, polyphenol content, the main natural antioxidants, signifi cantly decreased in olive oil as nitrogen increased in fruit. The decrease in polyphenols induced a signifi cant decrease in the oxidative stability of the oil and its bitterness. Tocopherol content, on the contrary, increased with nitrogen application, mainly by an increase in α-tocopherol, the main component in the olive oil. No effect was found on pigment content, particularly carotenoid and chlorophyllic pigments, neither on fatty acid composition. Olives (Olea europaea) are produced for extraction of olive oil for human consump- tion and for processing as table olives. Many factors may affect olive quality, including cultural practices such as fertilization. How- ever, no research has been published on the effect of mineral fertilizers on olive fruit or oil quality. Among the different essential elements, nitrogen is the most commonly applied in olive orchards, as occurs in other fruit tree species, because olives usually need N in greater amounts than other mineral nutrients (Fernandez-Escobar, 2004). With the increased value of the olive crop and the relatively low cost of N fertilization, olive growers have in- creased their application of N fertilizers based on the perception that an increase in N fertil- ization may insure high yields. This practice,

Histogenesis of sarcomatoid urothelial carcinoma of the urinary bladder: Evidence for a common clonal origin with divergent differentiation

Abstract: The histogenesis of sarcomatoid urothelial carcinoma, a rare neoplasm with bidirectional epithelial and mesenchymal differentiation, has been a matter of controversy. To clarify its origin, we analysed the status of X-chromosome inactivation in sarcomatoid urothelial carcinomas from 10 female patients and examined losses of heterozygosity (LOH) in these specimens and in additional 20 tumours from male patients. Six polymorphic microsatellite markers where genetic alterations occur frequently in early or advanced stages of urothelial carcinomas, including D3S3050, D8S261, IFNA, D9S177, D11S569 and TP53, were investigated in the current study. The identical pattern of non-random X-chromosome inactivation in both carcinomatous and sarcomatous components was identified in five of eight informative female patients, and the remaining three informative cases showed a random, but concordant, pattern of X-chromosome inactivation. The concordant X-chromosome inactivation results in all eight informative cases support the concept of a monoclonal origin of both components of this biphasic neoplasm. Among the tumours demonstrating loss of heterozygosity, high incidences of an identical pattern of allelic loss between carcinomatous and sarcomatous components were identified in genetic alterations associated with early carcinogenesis: 86% at D8S261, 78% at D11S569, 75% at D9S177 and 57% at IFNA. In contrast, concordant LOH patterns were less frequently observed for microsatellites related to advanced carcinogenesis: only 40% at D3S3050 and 40% at TP53. The significant overlap of loss of heterozygosity supports a monoclonal cell origin and suggests that clonal divergence may occur during tumour progression and differentiation. Divergent patterns of discordant allelic loss of microsatellite markers imply that heterogeneous pathogenetic pathways may exist in the evolution of this enigmatic neoplasm.

Educational data science in massive open online courses

Abstract: The current massive open online course (MOOC) euphoria is revolutionizing online education. Despite its expediency, there is considerable skepticism over various concerns. In order to resolve some of these problems, educational data science (EDS) has been used with success. MOOCs provide a wealth of information about the way in which a large number of learners interact with educational platforms and engage with the courses offered. This extensive amount of data provided by MOOCs concerning students' usage information is a gold mine for EDS. This paper aims to provide the reader with a complete and comprehensive review of the existing literature that helps us understand the application of EDS in MOOCs. The main works in this area are described and grouped by task or issue to be solved, along with the techniques used. WIREs Data Mining Knowl Discov 2017, 7:e1187. doi: 10.1002/widm.1187 This article is categorized under: Application Areas > Education and Learning