789 research outputs found
Development of an interactive virtual teaching system for the recognition of common minerals
El estudio de los minerales ocupa una parte importante del módulo básico materia Geología, prestándose dichos contenidos muy bien a un estudio descriptivo. Como actividad individual no presencial del alumno se propone en este trabajo la utilización de una aplicación informática que debe contribuir a la adquisición de destrezas y habilidades sobre el material geológico que nos rodea. Para programar la aplicación informática se construyó, en primer lugar, una base de datos y el material audiovisual necesario. Una vez realizado el programa informático, se sometió éste a un grupo crítico de usuarios y, finalmente, se realizó un periodo de pruebas para un grupo de alumnos de cursos superiores, a fin de afinar, fundamentalmente, sobre la facilidad de uso del programaThe study of minerals occupies an important part of the basic module of the subject of Geology, the said content lending itself very well to a descriptive study. As an individual, off-campus study activity, this project proposes the use of a computer application that contributes to the acquisition of skills concerning the geological material that surrounds us. To programme the computer application, firstly, a database and the necessary audiovisual material were compiled. Once the software was completed it was submitted to a user critique group and, finally, was put through a test period by a group of students in higher level courses, with the main aim of fine tuning the user-friendliness of the softwar
Sweet Wines Produced by an Innovative Winemaking Procedure: Colour, Active Odorants and Sensory Profile
The colour, aroma-active compounds and sensory properties of sweet wines from Pedro Ximenez grapes produced by means of an innovative winemaking procedure, based on controlled chamber-drying of grapes, partial fermentation of the must (to 4% or 8% vol ethanol) and subsequent accelerated ageing by contact with oak chips, were studied. Fermentation made the musts less brown and more yellow, whereas ageing made them darker and increased their brown, reddish and yellowish hues. Overall, the musts fermented to 8% vol ethanol exhibited higher odour activity values (OAVs). In addition, the musts aged with oak chips were slightly different from those without chips. Expert tasters gave the highest scores to the musts fermented to 8% (v/v) ethanol with 2 g/L of oak chips added. The winemaking process studied would allow the existing range of sweet wines from dried grapes to be expanded by using a fast, flexible, hygienic procedure
Chromatography-Olfactometry Study of the Aroma of Fino Sherry Wines
The aroma of Fino sherry wines produced by industrial biological aging for 0, 1.5, 2.5, 4.5, and 6 years in the Montilla-Moriles region (southern Spain) was studied by gas chromatography-olfactometry. The aroma sensations detected by 3 trained sniffers were classified according to their odor descriptors into 8 odorant series (fruity, empyreumatic, chemical, fatty, balsamic, vegetable, floral, and spicy), describing the aroma profile of the studied wines. The results showed 47 detected odors in the unaged wines, 50 in the 1.5-years-old wines and 59, 61 and 69 in the wines aged 2.5, 4.5, and 6 years, respectively. According to the frequency of the perceived aromas, the fruity and empyreumatic series were the most characteristic odorant series. By exception of chemical, floral and balsamic series without changes during aging of the wines, the remainder series increased their participation during the aging, mainly the fruity, empyreumatic, and fatty series
Thermodynamics of binding of divalent magnesium and manganese to uridine phosphates: implications for diabetes-related hypomagnesaemia and carbohydrate biocatalysis
<p>Abstract</p> <p>Background</p> <p>Although the necessity of divalent magnesium and manganese for full activity of sugar nucleotidyltransferases and glycosyltransferases is well known, the role of these metal cations in binding the substrates (uridine 5'-triphosphate, glucose-1-phosphate, <it>N</it>-acetylglucosamine-1-phosphate, and uridine 5'-diphosphate glucose), products (uridine 5'-diphosphate glucose, uridine 5'-diphosphate <it>N</it>-acetylglucosamine, pyrophosphate, and uridine 5'-diphosphate), and/or enzyme is not clearly understood.</p> <p>Results</p> <p>Using isothermal titration calorimetry we have studied the binding relationship between the divalent metals, magnesium and manganese, and uridine 5'-phosphates to determine the role these metals play in carbohydrate biosynthesis. It was determined from the isothermal titration calorimetry (ITC) data that Mg<sup>+2 </sup>and Mn<sup>+2 </sup>are most tightly bound to PP<sub><it>i</it></sub>, K<sub>b </sub>= 41,000 ± 2000 M<sup>-1 </sup>and 28,000 ± 50,000 M<sup>-1 </sup>respectively, and UTP, K<sub>b </sub>= 14,300 ± 700 M<sup>-1 </sup>and 13,000 ± 2,000 M<sup>-1 </sup>respectively.</p> <p>Conclusion</p> <p>Our results indicate that the formal charge state of the phosphate containing substrates determine the binding strength. Divalent metal cations magnesium and manganese showed similar trends in binding to the sugar substrates. Enthalpy of binding values were all determined to be endothermic except for the PP<sub><it>i </it></sub>case. In addition, entropy of binding values were all found to be positive. From this data, we discuss the role of magnesium and manganese in both sugar nucleotidyltransferase and glycosyltransferase reactions, the differences in metal-bound substrates expected under normal physiological metal concentrations and those of hypomagnesaemia, and the implications for drug design.</p
Surgical treatment of movement disorders in neurometabolic conditions
Refractory movement disorders are a common feature of inborn errors of metabolism (IEMs), significantly impacting quality of life and potentially leading to life-threatening complications such as status dystonicus. Surgical techniques, including deep brain stimulation (DBS) and lesioning techniques, represent an additional treatment option. However, the application and benefits of these procedures in neurometabolic conditions is not well understood. This results in challenges selecting surgical candidates and counseling patients preoperatively. In this review, we explore the literature of surgical techniques for the treatment of movement disorders in IEMs. Globus pallidus internus DBS has emerged as a beneficial treatment option for dystonia in Panthotate-Kinase-associated Neurodegeneration. Additionally, several patients with Lesch–Nyhan Disease have shown improvement following pallidal stimulation, with more robust effects on self-injurious behavior than dystonia. Although there are numerous reports describing benefits of DBS for movement disorders in other IEMs, the sample sizes have generally been small, limiting meaningful conclusions. Currently, DBS is preferred to lesioning techniques. However, successful use of pallidotomy and thalamotomy in neurometabolic conditions has been reported and may have a role in selected patients. Surgical techniques have also been used successfully in patients with IEMs to treat status dystonicus. Advancing our knowledge of these treatment options could significantly improve the care for patients with neurometabolic conditions
What determines adult cognitive skills?: Impacts of preschooling, schooling, and post-schooling experiences in Guatemala
"Most investigations into the importance and determinants of adult cognitive skills assume that (1) they are produced primarily by schooling, and (2) schooling is statistically predetermined or exogenous. This study uses longitudinal data collected in Guatemala over 35 years to investigate production functions for adult cognitive skills—that is, reading-comprehension skills and nonverbal cognitive skills—as being dependent on behaviorally determined preschooling, schooling, and post-schooling experiences. We use an indicator of whether the child was stunted (child height-for-age Z-scoreHuman capital, cognitive skills, Stunting, work experience, Development, Education, Gender, Health and nutrition,
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