253 research outputs found
La intervención socioeducativa en residencias de gente mayor. Protagonistas de su propia vida
Treballs Finals de Grau d'Educació Social, Facultat d'Educació, Universitat de Barcelona, Curs: 2015-2016, Tutor: Antonio Ruíz BuenoEl concepto “Gente Mayor”, engloba a todas aquellas personas que se encuentran en esa etapa de la vida una vez cumplidos los 65 años en adelante. La temática de esta investigación, por tanto se centra en las intervenciones socioeducativas que se llevan a cabo en residencias de Gente Mayor. Por lo que a lo largo de este estudio ha sido necesario hacer una pequeña búsqueda sobre conceptos como envejecimiento, vejez y gente mayor, para conocer las percepciones que se tenían sobre esta etapa de la vida. Además, utilizar la metodología de tipo mixto, nos ha permitido visualizar de manera más amplia el objeto de estudio y además nos ha posibilitado la visión desde diferentes ópticas. Para ello, hemos necesitado una muestra muy variada, estudiantes de educación social y testimonios de tres residencias de gente mayor, a las cuales teníamos fácil accesibilidad. Al ser una metodología mixta hemos utilizado dos tipos de instrumentos, de la metodología cualitativa, la entrevista (destinada a profesionales encargados de la dirección y la animación sociocultural) y de la cuantitativa, los cuestionarios (dirigidos a los estudiantes de educación social y los diferentes agentes que intervienen en las tres residencias escogidas).
Con esta investigación hemos podido ver, a grandes rasgos, que la visión que uno tiene sobre la vejez afecta en la manera de trabajar con ellos. Y teniendo en cuenta los tres escenarios con los que contaba esta investigación (tres residencias de gente mayor), al menos dos de ellos concluían con el concepto de Atención Centrada en la Persona como filosofía de centro
Xanthophyll cycles in the juniper haircap moss (Polytrichum juniperinum) and Antarctic hair grass (Deschampsia antarctica) on Livingston Island (South Shetland Islands, Maritime Antarctica)
The summer climate in Maritime Antarctica is characterised by high humidity and cloudiness with slightly above zero temperatures. Under such conditions, photosynthetic activity is temperature-limited and plant communities are formed by a few species. These conditions could prevent the operation of the photoprotective xanthophyll (VAZ) cycle as low irradiance reduces the excess of energy and low temperatures limit enzyme activity. The VAZ cycle regulates the dissipation of the excess of absorbed light as heat, which is the main mechanism of photoprotection in plants. To test whether this mechanism operates dynamically in Antarctic plant communities, we characterised pigment dynamics under natural field conditions in two representative species: the moss Polytrichum juniperinum and the grass Deschampsia antarctica. Pigment analyses revealed that the total VAZ pool was in the upper range of the values reported for most plant species, suggesting that they are exposed to a high degree of environmental stress. Despite cloudiness, there was a strong conversion of violaxanthin (V) to zeaxanthin (Z) during daytime. Conversely, the dark-induced enzymatic epoxidation back to V was not limited by nocturnal temperatures. In contrast with plants from other cold ecosystems, we did not find any evidence of overnight retention of Z or sustained reductions in photochemical efficiency. These results are of interest for modelling, remote sensing and upscaling of the responses of Antarctic vegetation to environmental challenges.The Spanish Ministry of Science, Innovation and Universities (MICIU/FEDER, EU) and the Basque Government funded this research through the projects CTM2014-53902-C2-2-P, PGC2018-093824-B-C44 and UPV/EHU IT-1018-16.
Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature
La Mujer Gitana: Del Mundo Privado al Público
La investigación presenta un estudio del sentido identitario genérico-étnico en mujeres gitanas de nuestro país. Se enmarca en la intersección de dos campos de estudio: el de mujer y el de mujer gitana. El abordaje del objeto de investigación se realizó desde tres dimensiones de análisis: El ¿Cómo soy?, vivencias y experiencias de vida e inequidades de género. Para ello he realizado una serie de entrevistas, utilizando un enfoque metodológico cualitativo que permitiera la exploración profunda y explicativa del objeto de investigación, siendo el análisis de contenido el instrumento metodológico empleado para el análisis de los resultados e interpretación de la informació
More than just lipid balls: quantitative analysis of plastoglobule attributes and their stress‑related responses
[EN] Main conclusion Plastoglobules are ubiquitous under non-stress conditions and their morphology, closely related to their composition, changes differently depending on the specific stress that the plant undergoes. Plastoglobules are lipoprotein structures attached to thylakoid membranes, which participate in chloroplast metabolism and stress responses. Their structure contains a coating lipid monolayer and a hydrophobic core that differ in composition. Their function in chloroplasts has been studied focussing on their composition. However, we currently lack a comprehensive study that quantitatively evaluates the occurrence and morphology of plastoglobules. Following a literature search strategy, we quantified the main morphological attributes of plastoglobules from photosynthetic chloroplasts of more than 1000 TEM images published over the last 53 years, covering more than 100 taxa and 15 stress types. The analysis shows that plastoglobules under non-stress conditions are spherical, with an average diameter of 100-200 nm and cover less than 3% of the chloroplast cross-section area. This percentage rises under almost every type of stress, particularly in senescence. Interestingly, an apparent trade-off between increasing either the number or the diameter of plastoglobules governs this response. Our results show that plastoglobules are ubiquitous in chloroplasts of higher plants under non-stress conditions. Besides, provided the specific molecular composition of the core and coat of plastoglobules, we conclude that specific stress-related variation in plastoglobules attributes may allow inferring precise responses of the chloroplast metabolism.This work was supported by the project PGC2018-093824-B-C44 from the Ministerio de Ciencia, Innovación y Universidades (MCIU, Spain) and the European Regional Development Fund (ERDF) and grant UPV/EHU IT-1018-16 from the Basque Government (Spain). MIA received a pre-doctoral grant from the Basque Government. We thank J. Miranda-Apodaca for helpful assistance with PCA analysis.
Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature
Unravelling metabolic mechanisms behind chloroplast desiccation tolerance: chlorophyllous fern spore as a new promising unicellular model
Se sustituye el preprint por el postprint el 23-11-2020Fern spores are unicellular structures produced by the sporophyte generation that give rise to the haploid gametophyte. When released from the sporangium, spores are desiccation tolerant (DT) in the royal fern (Osmunda regalis) and contain fully developed chloroplasts. As a consequence this type of spores are called chlorophyllous spores (CS). Upon transfer to germination conditions, CS initiate a process of imbibition that suppress DT in 72h, before the germination starts. In parallel to such change in DT, thylakoids undergo a profound remodelling in composition and function. Firstly, sustained quenching of chlorophyll fluorescence is relaxed, giving rise to photochemically active CS, while lipid composition shifts from that of a resting structure to a metabolically active cell. Basically trigalactolipids decreased in favour of monogalactolipids, with a parallel desaturation of fatty acids. Storage lipids such as triacylglycerol were quickly depleted. These results highlight the importance of the structure of thylakoids lipid as a key to protect membrane integrity during desiccation, together with the saturation of fatty acids and the constitutive chlorophyll quenching to prevent oxidative damage. The CS used here, in which the same cell shifts from DT to sensitive strategy in 72h, reveal its their potential as unicellular models for future studies on DT.This work was funded by (i) the Basque Government (research project UPV/EHU IT-1018-16; and Predoctoral Fellowship to MLP); (ii) the Spanish Ministry of Economy and Competitiveness (MINECO) and the ERDF (FEDER) (research project CTM2014-53902-C2-2-P, and Juan de la Cierva-Incorporation fellowship IJCI-2014-22489 to BFM)
Activation of violaxanthin cycle in darkness is a common response to different abiotic stresses: a case study in Pelvetia canaliculata
<p>Abstract</p> <p>Background</p> <p>In the violaxanthin (V) cycle, V is de-epoxidized to zeaxanthin (Z) when strong light or light combined with other stressors lead to an overexcitation of photosystems. However, plants can also suffer stress in darkness and recent reports have shown that dehydration triggers V-de-epoxidation in the absence of light. In this study, we used the highly stress-tolerant brown alga <it>Pelvetia canaliculata </it>as a model organism, due to its lack of lutein and its non-photochemical quenching independent of the transthylakoidal-ΔpH, to study the triggering of the V-cycle in darkness induced by abiotic stressors.</p> <p>Results</p> <p>We have shown that besides desiccation, other factors such as immersion, anoxia and high temperature also induced V-de-epoxidation in darkness. This process was reversible once the treatments had ceased (with the exception of heat, which caused lethal damage). Irrespective of the stressor applied, the resulting de-epoxidised xanthophylls correlated with a decrease in Fv/Fm, suggesting a common function in the down-regulation of photosynthetical efficiency. The implication of the redox-state of the plastoquinone-pool and of the differential activity of V-cycle enzymes on V-de-epoxidation in darkness was also examined. Current results suggest that both violaxanthin de-epoxidase (VDE) and zeaxanthin-epoxidase (ZE) have a basal constitutive activity even in darkness, being ZE inhibited under stress. This inhibition leads to Z accumulation.</p> <p>Conclusion</p> <p>This study demonstrates that V-cycle activity is triggered by several abiotic stressors even when they occur in an absolute absence of light, leading to a decrease in Fv/Fm. This finding provides new insights into an understanding of the regulation mechanism of the V-cycle and of its ecophysiological roles.</p
On the recalcitrant use of Arnon’s method for chlorophyll determination
Letters - New Phytol.This work was supported by the Basque Government (UPV/EHU-GV IT-1018-16), and by the Spanish Ministry of Economy and Competitiveness (MINECO) and the ERDF (FEDER) (CTM2014-53902-
C2-2-P). R.E. and B.F-M. received a ‘Juan de la Cierva-Incorporación" grant (IJCI-2014-21452 and IJCI-2014-22489, respectively)
Efectos de la ceguera sobre la actividad oxidativa de estructuras del sistema nervioso central y glandulares en ratas machos y hembras
Estudio de la influencia de la ceguera en la rata sobre la actividad oxidativa de partes de sistema nervioso y ovarios y testículos
Diversity of winter photoinhibitory responses: a case study in co-occurring lichens, mosses, herbs and woody plants from subalpine environments
Winter evergreens living in mountainous areas have to withstand a harsh combination of high light levels and low temperatures in wintertime. In response, evergreens can activate a photoprotective process that consists of the downregulation of photosynthetic efficiency, referred to as winter photoinhibition (WPI). WPI has been studied mainly in woody evergreens and crops even when, in many instances, other functional groups such as lichens or bryophytes dominate in alpine and boreal habitats. Thus, we aimed to (1) assess the occurrence of WPI within overwintering evergreens comprising woody species, herbs, mosses and lichens, (2) compare the recovery kinetics among those groups and (3) clarify the role of thylakoid proteins and pigments in both processes: WPI and recovery. With this aim, WPI was analyzed in 50 species in the field and recovery kineticcs were studied in one model species from each functional group. Results showed that high levels of WPI are much more frequent among woody plants than in any other group, but are also present in some herbs, lichens and mosses. Winter conditions almost always led to the de‐epoxidation of the xanthophyll cycle. Nevertheless, changes in the de‐epoxidation level were not associated with the activation/deactivation of WPI in the field and did not match changes in photochemical efficiency during recovery treatments. Seasonal changes in thylakoid proteins [mainly D1 (photosystem II core complex protein) and PsbS (essential protein for thermal dissipation)] were dependent on the functional group. The results highlight the diversity of physiological solutions and suggest a physical–mechanical reason for the more conservative strategy of woody species compared with other groups.Marie Curie IEF grant (328370 MELISSA) from the Euro- pean FP7-PEOPLE and a ‘Juan de la Cierva Incorporación’ grant (IJCI-2014-22489) from the Spanish Ministry of Econ- omy and Competitiveness (MINECO) and the European Regional Development Fund ERDF (FEDER). The work was also supported by the project BFU 2010 – 15021 and CTM2014-53902-C2-2-P from the MINECO and the ERDF (FEDER), and by the Basque Government (UPV/EHU-GV IT-624–13 and UPV/EHU-GV IT-1018-16
Rapid colour changes in Euglena sanguinea (Euglenophyceae) caused by internal lipid globule migration
The accumulation of red pigments under chronic stress is a response observed in most
groups of oxygenic photoautotrophs. It is thought that the red pigments in the cell shield
the chlorophyll located underneath from the light. Among these red pigments, the
accumulation of carotenoids is one of the most frequent cases. However, the synthesis
or degradation of carotenoids is a slow process and this response is usually only
observed when the stress is maintained over a period of time. In the Euglenophyte
Euglena sanguinea, this is due to the accumulation of a large amount of free and
esterified astaxanthin (representing 80% of the carotenoid pool). While reddening is a
slow and sometimes irreversible process in other phototrophs, reducing the efficiency of
light harvesting by chlorophyll, in E. sanguinea it is highly dynamic, capable of shifting
from red to green (and vice-versa) in 10-20 min. This change is not due to de novo
carotenogenesis, but to the relocation of cytoplasmic lipid globules where astaxanthin
accumulates. Thus, red globules migrate from the centre of the cell to peripheral
locations when photoprotection is demanded. This protective system seems to be so
efficient that other classical mechanisms are not operative in this species. For example,
despite the presence and operation of the diadino-diatoxanthin cycle, nonphotochemical
quenching (NPQ) is almost undetectable. Since E. sanguinea forms
extensive floating colonies, reddening can be observed at much greater scale than at a
cellular level, the mechanism described here being one of the fastest and most dramatic
colour changes attributable to photosynthetic organisms at cell and landscape level. In
sum, these data indicate an extremely dynamic and efficient photoprotective mechanism
based on organelle migration more than on carotenoid biosynthesis that prevents excess
light absorption by chlorophylls reducing the need for other protective processes related
to energy dissipation.This work was supported by the Basque Government [UPV/EHU-GV IT-1018-16] [UPV/EHU PPG17/67 – GV IT-1040-16], and by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Research and Development Foundation (FEDER) through (i) [CTM2014-53902-C2-2-P] national grant and (ii) a “Juan de la Cierva-Incorporación” postdoctoral grant [IJCI-2014-22489] to BFM
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