1,312 research outputs found
Towards improved measurement of financial protection in health
Christopher Millett and colleagues argue that new metrics are needed to better inform policy development on financial protection in health
Stability of Boolean Multilevel Networks
The study of the interplay between the structure and dynamics of complex
multilevel systems is a pressing challenge nowadays. In this paper, we use a
semi-annealed approximation to study the stability properties of Random Boolean
Networks in multiplex (multi-layered) graphs. Our main finding is that the
multilevel structure provides a mechanism for the stabilization of the dynamics
of the whole system even when individual layers work on the chaotic regime,
therefore identifying new ways of feedback between the structure and the
dynamics of these systems. Our results point out the need for a conceptual
transition from the physics of single layered networks to the physics of
multiplex networks. Finally, the fact that the coupling modifies the phase
diagram and the critical conditions of the isolated layers suggests that
interdependency can be used as a control mechanism.Comment: Final version. It includes the generalization to the case of having
an arbitrary number of layer
Molecular heterogeneity of large-conductance calcium-activated potassium channels in canine intracardiac ganglia
Large conductance calcium-activated potassium (BK) channels are widely expressed in the nervous system. We have recently shown that principal neurons from canine intracardiac ganglia (ICG) express a paxilline- and TEA-sensitive BK current, which increases neuronal excitability. In the present work, we further explore the molecular constituents of the BK current in canine ICG. We found that the β1 and β4 regulatory subunits are expressed in ICG. Single channel voltage-dependence at different calcium concentrations suggested that association of the BKα with a particular β subunit was not enough to explain the channel activity in this tissue. Indeed, we detected the presence of several splice variants of the BKα subunit. In conclusion, BK channels in canine ICG may result from the arrangement of different BKα splice variants, plus accessory β subunits. The particular combinations expressed in canine IC neurons likely rule the excitatory role of BK current in this tissue
Refuerzo de conocimientos de BioquÃmica aplicando juegos de letras o de palabras sencillos
Introducció i problema: Els jocs són molt apreciats per la població en general, i per això vam fer una cerca de diversos jocs amb la finalitat d’utilitzar-los per a reforçar els coneixements en bioquÃmica dels alumnes del grau de QuÃmica de la Universitat de Barcelona. Els jocs dels llibres de passatemps es basen en dues possibilitats: números i lletres. Entre els jocs de lletres, destaquen els mots encreuats, auto definits, paraules creuades i sopes de lletres. Metodologia: Per reforçar els coneixements dels estudiants de BioquÃmica, vam realitzar una recerca de jocs de paraules usats en l’aprenentatge de la gramà tica als idiomes, per adaptar-los després a la nomenclatura i estructura de les biomolècules. Seguint una aproximació conductista, vam fer servir el model de Dick i Carey. Resultats i discussió: Els jocs més senzills sobre paraules es basen en cercar dins d’un conjunt de paraules, aquelles que tinguin alguna part en comú. En aquest sentit, vam implementar jocs de rimes, en el què les paraules acaben en –ina (terminació freqüent dels aminoà cids, bases nitrogenades, nucleòsids i algunes proteïnes), en –osa (terminació freqüent dels hidrats de carboni), o en – ic / –at (terminació freqüent dels à cids grassos i altres à cids intermediaris del metabolisme, o de les seves sals corresponents). Aixà doncs, els alumnes poden observar aquestes caracterÃstiques a la nomenclatura. D'altra banda, també vam implementar jocs de paraules incompletes que es basen en completar els noms dels metabòlits tot utilitzant grups de lletres a escollir. Els jocs es van classificar en 4 grups i aquà se’n presenten alguns exemples. Pel que fa a la dificultat, els jocs tipus dòmino són els més difÃcils de resoldre, ja que cal conèixer tant la nomenclatura com l’estructura de les biomolècules. Conclusions: La nostra proposta inclou diversos jocs de paraules que permeten reforçar els coneixements de BioquÃmica.Introduction and problem: Games are highly appreciated by general population, so we decided to search several games in order to use them to reinforce the knowledge in biochemistry of students from the Chemistry Degree of the University of Barcelona. The puzzle book games are based on two possibilities: numbers and letters. Among the letters’ games the most frequent are crossword, self-defined crosswords, crossword puzzles and word search puzzles. Methodology: To reinforce students’ knowledge in Biochemistry, we performed a search for word games based in those used in language grammar learning, to then adapt them to the nomenclature and structure of biomolecules in Biochemistry. Following a behaviorist approach, we applied the model of Dick and Carey. Results and discussion: The simplest word games are based on searching in a set of words, those that have some common part. In this sense, we implemented rhyming games, in which the words ended in –ine (a frequent ending of amino acids, nitrogenous bases, nucleosides and some proteins), in –ose (a frequent ending of carbohydrates), or ended in –ic / –ate (frequent ending of fatty acids and other acids intermediate of the metabolism, or their corresponding salts). Thus, students were able to observe these characteristics in the nomenclature. On the other hand, we also implemented incomplete words’ games that are based on completing the names of the metabolites using groups of letters. Games were classified into 4 groups and some examples of them are presented. Regarding difficulty, domino games are the most difficult to solve since they require knowing both the nomenclature and structure of biomolecules. Conclusions: Our proposal includes several word games that allow the reinforcement of the knowledge in the subject of Biochemistry.Introducción y problema: Los juegos son muy apreciados por la población en general, asà que realizamos una búsqueda de diversos juegos con la finalidad de utilizarlos para reforzar los conocimientos en bioquÃmica de los alumnos del grado de QuÃmica de la Universidad de Barcelona. Los juegos de los libros de pasatiempos están basados en dos posibilidades: números y letras. Entre los juegos de letras los más frecuentes son los crucigramas, autodefinidos, palabras cruzadas y sopas de letras. MetodologÃa: Para reforzar los conocimientos de los estudiantes en BioquÃmica, realizamos una búsqueda de juegos de palabras usados en el aprendizaje de gramática de idiomas, para luego adaptarlos a la nomenclatura y estructura de biomoléculas en BioquÃmica. Siguiendo una aproximación conductista, utilizamos el modelo de Dick y Carey. Resultados y discusión: Los juegos más sencillos sobre palabras se basan en buscar dentro de un conjunto de palabras, aquellas que tengan alguna parte en común. En este sentido, implementamos juegos de rimas, en los que las palabras terminan en –ina (terminación frecuente de los aminoácidos, bases nitrogenadas, nucleósidos y algunas proteÃnas), en –osa (terminación frecuente de los hidratos de carbono), o en –ico / –ato (terminación frecuente de los ácidos grasos y otros ácidos intermediarios del metabolismo, o de sus sales correspondientes). Asà pues, los alumnos pueden observar estas caracterÃsticas en la nomenclatura. Por otro lado, también implementamos juegos de palabras incompletas que se basan en completar los nombres de los metabolitos utilizando grupos de letras a escoger. Los juegos se clasificaron en 4 grupos y se presentan algunos ejemplos de estos. Respecto a la dificultad, los juegos tipo dominó son los más difÃciles de resolver, pues requieren conocer tanto la nomenclatura como la estructura de las biomoléculas. Conclusiones: Nuestra propuesta incluye diversos juegos de palabras que permiten reforzar conocimientos de BioquÃmica
First evidence of paleoearthquakes along the Carboneras Fault Zone (SE Iberian Peninsula): Los Trances site
Seismogenic faults that have not produced historical large earthquakes remain unnoticed and, thus, are dangerously left out from seismic hazard analyses. The seismogenic nature of the Carboneras Fault Zone, a left-lateral strikeslip fault in the Eastern Betic Shear Zone (southeastern Spain), has not been fully explored to date in spite of having a morphological expression equivalent to the Alhama de Murcia Fault, a seismogenic fault in the same tectonic system. This study provides the first paleoseismic evidence of the seismogenic nature of the Carboneras Fault Zone, based on the analysis of 3 trenches at Los Trances site, on the northwestern edge of the La Serrata Range. Cross cutting relationships and numerical dating, based on radiocarbon, thermoluminescence and U-series, reveal a minimum of 4 paleoearthquakes: Paleoearthquake1 (the oldest) and Paleoearthquake2 took place after 133ka, Paleoearthquake3 occurred between 83-73ka and Paleoearthquake4 happened after 42.5ka (probably after 30.8ka), resulting in a maximum possible average recurrence of 33ka. This value, based on a minimum amount of paleoearthquakes, is probably overestimated, as it does not scale well with published slip-rates derived from offset channels or GPS geodetical data. The characterization of this fault as seismogenic, implies that it should be considered in the seismic hazard analyses of the SE Iberian Peninsula
Does the use of nest materials in a ground-nesting bird result from a compromise between the risk of egg overheating and camouflage?
Many studies addressing the use of nest materials by animals have
focused on only one factor to explain its function. However, the
consideration of more than one factor could explain the apparently
maladaptive choice of nest materials that make nests conspicuous to
predators. We experimentally tested whether there is a trade-off in the
use of nest materials between the risks of egg predation versus
protection from overheating. We studied the ground-nesting Kentish
plover, Charadrius alexandrinus, in southern Spain. We added
materials differing in thermal properties and coloration to the nests,
thus affecting rates of egg heating, nest temperature and camouflage.
Before these manipulations, adults selected materials that were lighter
than the microhabitat, probably to buffer the risk of egg overheating.
However, the adults did not keep the lightest experimental materials,
probably because they reduced camouflage, and this could make the
nests even more easily detectable to predators. In all nests, adults
removed most of the experimental materials independently of their
properties, so that egg camouflage returned to the original situation
within a week of the experimental treatments. Although the thermal
environment may affect the choice of nest materials by plovers,
ambient temperatureswere not so high at our study site as to determine
the acceptance of the lightest experimental materials
EXPLORING THE IMPACT OF APOE POLYMORPHISM ON THE MOLECULAR, MORPHOLOGICAL AND FUNCTIONAL PROFILE OF iPSC-DERIVED ASTROCYTES FROM ALZHEIMER'S PATIENTS
Comunicación presentada a FENS Forum 2022Alzheimer¿s disease (AD) is pathologically characterised by the presence of amyloid-beta plaques, neurofibrillary tangles containing hyperphosphorylated Tau protein, neuroinflammation and neuronal death leading to progressive cognitive impairment. The ¿4 allele of the gene encoding apolipoprotein E (APOE), which is mainly expressed in glial cells, is the strongest genetic risk factor for sporadic AD. Increasing evidence has shown that APOE4 may disrupt normal astrocyte activity, potentially contributing to AD pathology, but the impact of different APOE alleles on astrocyte differentiation, maturation and function is not yet fully understood. To go in depth on these questions, we obtained induced pluripotent stem cells (iPSCs) from fibroblasts of AD patients carrying ¿3 and ¿4 alleles (in homozygosis) and from healthy patients. We also used gene-edited iPSC lines homozygous for the main APOE variants and an APOE knock-out line. iPSC-derived human astrocytes were generated by establishing a differentiation protocol through the consecutive addition of small molecules and growth factors, and the expression of typical markers (GFAP, GLT1, AQP4 and S100beta) and APOE was analysed. In addition, astrocytes exhibited functional features like glutamate uptake capacity and calcium waves production. They also responded to an inflammatory stimulus (IL-1beta and TNF-alpha) or to the presence of amyloid-beta 1-42 peptide by changing their morphology and increasing the expression levels of pro-inflammatory factors and cytokines. Our results shed light on the potential dual role of APOE polymorphism and the individual¿s genetic background in favouring or perhaps preventing AD pathology
ANALYSING THE MOLECULAR, MORPHOLOGICAL AND FUNCTIONAL PROFILE OF iPSC-DERIVED ASTROCYTES FROM ALZHEIMER'S DISEASE PATIENTS
Comunicación presentada en Global Summit on Neurodegenerative Diseases NEURO 2020/22The ε4 allele of the gene encoding apolipoprotein E (APOE), which is mainly expressed in glial cells, is the strongest genetic risk factor for sporadic AD. Increasing evidence has shown that APOE4 may disrupt normal astrocyte activity, potentially contributing to AD pathology, but the impact of different APOE alleles on astrocyte maturation and function as well as their inflammatory profile is not yet fully understood. To answer these questions, we obtained induced pluripotent stem cells (iPSCs) from fibroblasts of AD patients carrying ε3 and ε4 alleles (in homozygosis) and from healthy patients. We also used gene-edited iPSC lines homozygous for the main APOE variants and an APOE knock-out line. iPSC-derived human astrocytes were generated through the consecutive addition of small molecules and growth factors to the culture medium, and the expression of typical markers (GFAP, GLT1, AQP4 and S100beta) was analysed. In addition, astrocytes exhibited functional features like glutamate uptake capacity and calcium waves. They also responded to an inflammatory stimulus (IL-1beta and TNF-alpha) or to the presence of amyloid-beta 1-42 peptide by changing their morphology and increasing the expression levels of pro-inflammatory factors and cytokines. Our results shed light on the potential dual role of APOE polymorphism and the individual's genetic background in favouring or perhaps preventing AD pathology
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