Mineralogical characterization of the granite of Golpejas (Salamanca)

En el presente trabajo se propone una sistemática de caracterización mineralógica a través de la aplicación de la espectrorradiometría de campo VNIR-SWIR (visible e infrarrojo cercano y de onda corta) para el estudio de caolines. La caracterización mineralógica de base ha sido la Difracción de Rayos X, de acuerdo con la rutina clásica de los estudios de minerales arcillosos. Como caso de estudio, se ha seleccionado el yacimiento de estaño de Golpejas (Salamanca). El yacimiento estannífero de Golpejas está constituido por varias láminas de un microgranito albítico que da lugar a estructuras más o menos circulares, cortando a los metasedimentos del Complejo Esquisto-Grauváquico en la Zona Centro-Ibérica. El emplazamiento tuvo lugar durante la fase extensional de la Orogenia Varisca y los procesos de greisenización y caolinitización hidrotermal aumentaron la concentración de Sn,Ta,Nb, y dieron lugar a la formación de la caolininita por alteración de los feldespatos primarios. Puesto que los minerales del grupo de la caolinita (caolinita,dickita y nacrita) presentan rasgos característicos y diferenciadores en el intervalo de longitudes de onda con la técnica propuesta (VNIR-SWIR), los espectros obtenidos junto con las técnicas clásicas de estudio de minerales arcillosos permiten la caracterización mineralógica del caolín de Golpejas (Salamanca).In the present work, we propose a systematics of mineralogical characterization through field spectrometry VNIR-SWIR (visible, near-infrared and short-wave infrared) as well as the techniques most used for the identification and semiquantification of special clays. The basis of the mineralogical study has been X-ray diffraction, according to the classical routine of studies on clay minerals. As a case of study, the tin deposit of Golpejas (Salamanca) has been selected. The Golpejas tin deposit consists of several sheets of albite microgranite, more or less circular in shape, that intersect the metasediments of the schist-graywacke complex in the Iberian Zone. The emplazament took place during the extensional phase of Variscan Orogeny and the processes of greaseization and hydrothermal kaolinitization increased the concentration of Sn, Nb, Ta as well as kaolin. The albite leucogranite carrying the mineralization show a strong kaolinitization that occurred during the final phase of the mineralizing stage. As kaolinite group minerals (kaolinite, dickite and nacrite) have characteristic and differentiating features in the range of wavelenght studied with the proposed technique (VNIR-SWIR), the spectra obtained together with the classic clay mineral study techniques, allow us the mineralogical characterization of the Golpejas kaolin.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Disruption of both chloroplastic and cytosolic FBPase genes results in a dwarf phenotype and important starch and metabolite changes in Arabidopsis thaliana

In this study, evidence is provided for the role of fructose-1,6-bisphosphatases (FBPases) in plant development and carbohydrate synthesis and distribution by analysing two Arabidopsis thaliana T-DNA knockout mutant lines, cyfbp and cfbp1, and one double mutant cyfbp cfbp1 which affect each FBPase isoform, cytosolic and chloroplastic, respectively. cyFBP is involved in sucrose synthesis, whilst cFBP1 is a key enzyme in the Calvin–Benson cycle. In addition to the smaller rosette size and lower rate of photosynthesis, the lack of cFBP1 in the mutants cfbp1 and cyfbp cfbp1 leads to a lower content of soluble sugars, less starch accumulation, and a greater superoxide dismutase (SOD) activity. The mutants also had some developmental alterations, including stomatal opening defects and increased numbers of root vascular layers. Complementation also confirmed that the mutant phenotypes were caused by disruption of the cFBP1 gene. cyfbp mutant plants without cyFBP showed a higher starch content in the chloroplasts, but this did not greatly affect the phenotype. Notably, the sucrose content in cyfbp was close to that found in the wild type. The cyfbp cfbp1 double mutant displayed features of both parental lines but had the cfbp1 phenotype. All the mutants accumulated fructose-1,6-bisphosphate and triose-phosphate during the light period. These results prove that while the lack of cFBP1 induces important changes in a wide range of metabolites such as amino acids, sugars, and organic acids, the lack of cyFBP activity in Arabidopsis essentially provokes a carbon metabolism imbalance which does not compromise the viability of the double mutant cyfbp cfbp1.España, Ministerio de Economía y Competitividad BIO2009-07297España, Ministerio de Economía y Competitividad BIO2012-33292Junta de Andalucía P07-CVI-279

Disruption of both chloroplastic and cytosolic FBPase genes results in a dwarf phenotype and important starch and metabolite changes in Arabidopsis thaliana

In this study, evidence is provided for the role of fructose-1,6-bisphosphatases (FBPases) in plant development and carbohydrate synthesis and distribution by analysing two Arabidopsis thaliana T-DNA knockout mutant lines, cyfbp and cfbp1, and one double mutant cyfbp cfbp1 which affect each FBPase isoform, cytosolic and chloroplastic, respectively. cyFBP is involved in sucrose synthesis, whilst cFBP1 is a key enzyme in the Calvin–Benson cycle. In addition to the smaller rosette size and lower rate of photosynthesis, the lack of cFBP1 in the mutants cfbp1 and cyfbp cfbp1 leads to a lower content of soluble sugars, less starch accumulation, and a greater superoxide dismutase (SOD) activity. The mutants also had some developmental alterations, including stomatal opening defects and increased numbers of root vascular layers. Complementation also confirmed that the mutant phenotypes were caused by disruption of the cFBP1 gene. cyfbp mutant plants without cyFBP showed a higher starch content in the chloroplasts, but this did not greatly affect the phenotype. Notably, the sucrose content in cyfbp was close to that found in the wild type. The cyfbp cfbp1 double mutant displayed features of both parental lines but had the cfbp1 phenotype. All the mutants accumulated fructose-1,6-bisphosphate and triose-phosphate during the light period. These results prove that while the lack of cFBP1 induces important changes in a wide range of metabolites such as amino acids, sugars, and organic acids, the lack of cyFBP activity in Arabidopsis essentially provokes a carbon metabolism imbalance which does not compromise the viability of the double mutant cyfbp cfbp1.España, Ministerio de Economía y Competitividad BIO2009-07297España, Ministerio de Economía y Competitividad BIO2012-33292Junta de Andalucía P07-CVI-279

La tecnología de impresión 3D utilizada en odontología

El desarrollo de la tecnología digital abre una puerta de oportunidad en el avance de técnicas y procedimientos que mejoran la eficiencia de las Ciencias de la Salud, entre ellas la Odontología; esta revisión desarrolla algunos avances en diferentes procedimientos clínicos, auxiliados por la impresión 3D, considerando los conceptos básicos y su aplicación clínica en las diferentes ramas de la clínica buco-dental

From Nuevo León to the USA and Back Again: Transnational Students in Mexico

The movement of Mexicans to the United States is both longstanding and long studied and from that study we know that for many newcomers the attachment to the receiving community is fraught and tentative. The experience of immigrant children in U.S. schools is also relatively well studied and reveals challenges of intercultural communication as well as concurrent and contradictory features of welcome and unwelcome. What is less well known, in the study of migration generally and of transnational students in particular, is how students moving in a less common direction — from the U.S. to Mexico — experience that movement. Based on visits to 173 randomly selected classrooms in the state of Nuevo León Mexico, this study shares survey and interview data from 208 of the 242 students encountered who had previous experience attending school in the United States