Experiencias caseras que muestran aspectos del funcionamiento de la vista, el gusto y el tacto

En el laboratorio de Biología explicamos el funcionamiento de algunos de nuestros órganos de los sentidos (vista, olfato, gusto y tacto) a través de una serie de experiencias que a lo largo de los años han evidenciado ser muy didácticas. Muestran parte del proceso físico en sí y, al exigir la participación activa del alumnado, permiten que éste aprenda divirtiéndose. Lo fácil y barato que resulta realizar estas experiencias, junto a su gran capacidad degenerar asombro, invitan a su difusión y ejecución a todos los niveles

Easy-to-implement experiences that show some aspects of how the senses of sight, taste and touch work

En el laboratorio de Biología explicamos el funcionamiento de algunos de nuestros órganos de los sentidos (vista, olfato, gusto y tacto) a través de una serie de experiencias que a lo largo de los años han evidenciado ser muy didácticas. Muestran parte del proceso físico en sí y, al exigir la participación activa del alumnado, permiten que éste aprenda divirtiéndose. Lo fácil y barato que resulta realizar estas experiencias, junto a su gran capacidad de generar asombro, invitan a su difusión y ejecución a todos los niveles

Learning Chemistry with candies

Las golosinas (caramelos, chicles, nubes, palotes, papas fritas, etc.) nos gustan a casi todos y gozan de una imagen positiva, a pesar de sus efectos secundarios si no se consumen con moderación. Aprovechándonos de esa buena imagen y de la gran variedad de golosinas que existen en el mercado, hemos diseñado una serie de experimentos con los que podemos explicar distintos tipos de reacciones químicas (acido-base, oxidación-reducción, endotérmicas…), la actuación de un indicador e, incluso, podemos comparar cantidades de vitamina C. En todas las actividades se persigue explicar algún aspecto de la Química que, en general, el público desconoce, captando su atención, por ejemplo, mediante cambios de color espectaculares y con las golosinas como protagonistas. Así mismo, estas experiencias pueden emplearse como recursos didácticos para alumnos de 4o E.S.O. y Bachillerato, apoyando los contenidos teóricos del currículum

El efecto socializador del medio televisivo en jóvenes. Influencia de las conductas de gestión del conflicto mostradas por personajes de series de ficción

Clearly the influence of television in society, being the study of violence and its impact on children and young people the subject of most investigations. How to manage conflict becomes a variable indicative of violent behavior, therefore, this work has been an analysis of the styles of managing conflicts of characters in the television series most viewed by young people, being results based on the sex of the characters analyzed, and associating these different styles of behaviors and attitudes that young men and women assigned to.Resulta evidente la influencia del medio televisivo en la sociedad, siendo el estudio de la violencia y sus consecuencias en niños y jóvenes el objeto de la mayoría de las investigaciones al respecto. El modo de gestionar los conflictos se convierte en una variable indicativa de conductas violentas, por ello, este trabajo ha realizado un análisis de los estilos de gestionar conflictos de personajes de las series televisivas más vistas por jóvenes, hallándose resultados en función del sexo de los personajes analizados, y asociándose estas diferencias de estilos a conductas y actitudes que los jóvenes asignan a hombres o mujeres

Effect of Heating on Avian (Cortical and Medullary) Bone Chemistry, Mineralogy and Structural Organization

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.cgd.3c00648.The study of bone changes induced by heating is highly relevant for forensic and archeological analyses as well as for the production of bone-derived materials with novel properties and applications. In the present study, we study in detail how different types of avian bone (cortical, medullary) transform during thermal treatments (up to 800 °C) using different analytical techniques such as thermogravimetry (TGA-DSC), electron microscopy, X-ray diffraction and infrared spectroscopy. We show that bone transformation following thermal treatments is strongly influenced by bone architecture, the composition of the organic matrix, and the integration of the mineral with the organic fractions. For instance, in avian cortical bone, the apatite nanocrystals are integrated within collagen fibrils and coated with phosphorylated proteins. During heating, the collagen losses structural order and denatures (at around 200 °C), losing all structural integrity at 300 °C. In the bone mineral fraction, there is a gradual conversion of phosphate, in poorly crystalline/amorphous environments, into apatite (up to 400 °C). However, it is not until all organics are completely lost at around 600 °C that recrystallization sets in with a rapid increase in the size of apatite crystals. Also, during recrystallization, foreign ions (Mg2+, Na+) are expelled from the apatite lattice to the crystal surface, and the degree of preferential orientation of the apatite crystals increases as larger, well-oriented apatite crystals grow epitaxially at the expense of smaller, randomly oriented crystals. However, the scenario is different for the medullary bone. In this case, with an organic matrix rich in noncollagen proteins and proteoglycans, the recrystallization sets in at much lower temperatures (around 400 °C compared to 600 °C in cortical bone). Thus, the association of mineral and organic components controls recrystallization, particularly in the case of apatite nanocrystals within collagen fibrils in cortical bone. Also, the calcination process creates additional microporosity in both types of bone, increasing the bone mineral surface area and reactivity. The information obtained in this study provides a better understanding of the dynamics of bone transformation during alteration in natural processes (e.g., diagenesis, burning) and how bone mineral characteristics can be modified for specific applications (e.g., bone grafts, waste removal, or chromatography).Junta de Andalucía (P20_00208 and P20_00207)Spanish government (PID2020-116660GB-I00), UCE-PP2016-05Biotechnology Institute (University of Granada

Plasticity in organic composition maintains biomechanical performance in shells of juvenile scallops exposed to altered temperature and pH conditions

This study was funded by PIA ANID ACT 172037 for international collaborative research among Chile (NAL, MAL, JV, CG-H, CD) and Spain (ARN, CG). Author also acknowledges support from Fondecyt 1190444 (MAL), Fondecyt 1210171 (CAV) and ANID - Millennium Science Initiative Program - ICN2019_015 (SECOS) (NAL, MAL and CAV). ANID doctoral scholarhip #21210012 to SB. ANID PFCHA / Doctorados Becas Chile Chile/2019-CEL00011051 to AA-O and DICYT from USACH to AA-O and CG-H during the execution of sample processing and analysis. We also acknowledge to Anita Quiroga, Jhonny Rojas for their support in lab procedures, and the staff at BIO-CT Lab (Universidad de Chile). We are grateful to B. Broitman and two anonymous reviewers who provided valuable comments on previous version of the manuscript.The exposure to environmental variations in pH and temperature has proven impacts on benthic ectotherms calcifiers, as evidenced by tradeoffs between physiological processes. However, how these stressors affect structure and functionality of mollusk shells has received less attention. Episodic events of upwelling of deep cold and low pH waters are well documented in eastern boundary systems and may be stressful to mollusks, impairing both physiological and biomechanical performance. These events are projected to become more intense, and extensive in time with ongoing global warming. In this study, we evaluate the independent and interactive effects of temperature and pH on the biomineral and biomechanical properties of Argopecten purpuratus scallop shells. Total organic matter in the shell mineral increased under reduced pH (~ 7.7) and control conditions (pH ~ 8.0). The periostracum layer coating the outer shell surface showed increased protein content under low pH conditions but decreasing sulfate and polysaccharides content. Reduced pH negatively impacts shell density and increases the disorder in the orientation of calcite crystals. At elevated temperatures (18 °C), shell microhardness increased. Other biomechanical properties were not affected by pH/ temperature treatments. Thus, under a reduction of 0.3 pH units and low temperature, the response of A. purpuratus was a tradeoff among organic compounds (biopolymer plasticity), density, and crystal organization (mineral plasticity) to maintain shell biomechanical performance, while increased temperature ameliorated the impacts on shell hardness. Biopolymer plasticity was associated with ecophysiological performance, indicating that, under the influence of natural fluctuations in pH and temperature, energetic constraints might be critical in modulating the long-term sustainability of this compensatory mechanism.PIA ANID ACT 172037Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1190444 1210171ANID - Millennium Science Initiative Program ICN2019_015ANID doctoral scholarhip 21210012ANID PFCHA / Doctorados Becas Chile Chile/2019-CEL0001105

The enterocyte proteome of gilthead seabream (Sparus Aurata) acclimated to two salinited conditions

Comunicaciones a congreso

Molecular characterization of autophagic and apoptotic signaling induced by sorafenib in liver cancer cells

Sorafenib is the unique accepted molecular targeted drug for the treatment of patients in advanced stage of hepatocellular carcinoma. The current study evaluated cell signaling regulation of endoplasmic reticulum (ER) stress, c-Jun-N-terminal kinase (JNK), Akt, and 5′AMP-activated protein kinase (AMPK) leading to autophagy and apoptosis induced by sorafenib. Sorafenib induced early (3–12 hr) ER stress characterized by an increase of Ser51P-eIF2α/eIF2α, C/EBP homologous protein (CHOP), IRE1α, and sXBP1, but a decrease of activating transcription factor 6 expression, overall temporally associated with the increase of Thr183,Tyr185P-JNK1/2/JNK1/2, Thr172P-AMPKα, Ser413P-Foxo3a, Thr308P-AKt/AKt and Thr32P-Foxo3a/Foxo3a ratios, and reduction of Ser2481P-mammalian target of rapamycin (mTOR)/mTOR and protein translation. This pattern was related to a transient increase of tBid, Bim EL, Beclin-1, Bcl-xL, Bcl-2, autophagy markers, and reduction of myeloid cell leukemia-1 (Mcl-1) expression. The progressive increase of CHOP expression, and reduction of Thr308P-AKt/AKt and Ser473P-AKt/AKt ratios were associated with the reduction of autophagic flux and an additional upregulation of Bim EL expression and caspase-3 activity (24 hr). Small interfering-RNA (si-RNA) assays showed that Bim, but not Bak and Bax, was involved in the induction of caspase-3 in sorafenib-treated HepG2 cells. Sorafenib increased autophagic and apoptotic markers in tumor-derived xenograft model. In conclusion, the early sorafenib-induced ER stress and regulation of JNK and AMPK-dependent signaling were related to the induction of survival autophagic process. The sustained drug treatment induced a progressive increase of ER stress and PERK-CHOP-dependent rise of Bim EL, which was associated with the shift from autophagy to apoptosis. The kinetic of Bim EL expression profile might also be related to the tight balance between AKt- and AMPK-related signaling leading to Foxo3a-dependent BIM EL upregulation.Ministerio de Economía y Competitividad BFU2016‐75352‐PInstituto de Salud Carlos III PI15/00034, PI13/ 00021, PI16/00090, PI14/01349Ministerio de Educación FPU16/05127, FPU12/01433, FPU13/01237Junta de Andalucía CTS-6264, PI-00025-2013, PI-0127-2013, PI-0198-201

Potential--density pairs for spherical galaxies and bulges: the influence of scalar fields

A family of potential--density pairs has been found for spherical halos and bulges of galaxies in the Newtonian limit of scalar--tensor theories of gravity. The scalar field is described by a Klein--Gordon equation with a source that is coupled to the standard Poisson equation of Newtonian gravity. The net gravitational force is given by two contributions: the standard Newtonian potential plus a term stemming from massive scalar fields. General solutions have been found for spherical systems. In particular, we compute potential--density pairs of spherical galactic systems, and some other astrophysical quantities that are relevant to generating initial conditions for spherical galaxy simulations.Comment: Paper accepted for publication in MNRAS, with four figure