67 research outputs found

    La naturaleza, ¿Viva o muerta?: Un debate secular

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    Pensadores como Hans Jonas y Collingwood han destacado la apuesta de la ciencia moderna por la no-vida, con su reducción teórica delo viviente a composición mecánica. Sin embargo, la tradición mecanicista, anti vitalista, se halla enfrentada históricamente a otra, vitalista, que hunde sus raíces en Grecia y que tiene como hitos importantes el «primer Renacimiento» y la Naturphilosop-hie. Las dificultades con que tropiezan los biólogos a la hora de intentar definir la vida muestran que el problema planteado conserva plena vigencia. Habría, tal vez, que apostar por una definición más abierta y más inclusiva

    Base de datos de abejas ibéricas

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    Resumen: Las abejas son un grupo extremadamente diverso con más de 1000 especies descritas en la península ibérica. Además, son excelentes polinizadores y aportan numerosos servicios ecosistémicos fundamentales para la mayoría de ecosistemas terrestres. Debido a los diversos cambios ambientales inducidos por el ser humano, existen evidencias del declive de algunas de sus poblaciones para ciertas especies. Sin embargo, conocemos muy poco del estado de conservación de la mayoría de especies y de muchas de ellas ignoramos cuál es su distribución en la península ibérica. En este trabajo presentamos un esfuerzo colaborativo para crear una base de datos de ocurrencias de abejas que abarca la península ibérica e islas Baleares que permitirá resolver cuestiones como la distribución de las diferentes especies, preferencia de hábitat, fenología o tendencias históricas. En su versión actual, esta base de datos contiene un total de 87 684 registros de 923 especies recolectados entre 1830 y 2022, de los cuales un 87% presentan información georreferenciada. Para cada registro se incluye información relativa a la localidad de muestreo (89%), identificador y colector de la especie (64%), fecha de captura (54%) y planta donde se recolectó (20%). Creemos que esta base de datos es el punto de partida para conocer y conservar mejor la biodiversidad de abejas en la península ibérica e Islas Baleares. Se puede acceder a estos datos a través del siguiente enlace permanente: https://doi.org/10.5281/zenodo.6354502 Palabras clave: Anthophila; Apoidea; base de datos; biodiversidad; fenología; península ibérica; polinizadores Iberian bees database Abstract: Bees are a diverse group with more than 1000 species known from the Iberian Peninsula. They have increasingly received special attention due to their important role as pollinators and providers of ecosystem services. In addition, various rapid human-induced environmental changes are leading to the decline of some of its populations. However, we know very little about the conservation status of most species and for many species, we hardly know their true distributions across the Iberian Peninsula. Here, we present a collaborative effort to collate and curate a database of Iberian bee occurrences to answer questions about their distribution, habitat preference, phenology, or historical trends. In total we have gathered 87 684 records from the Iberian Peninsula and the Balearic Islands of 923 different species with 87% of georeferenced records collected between 1830 and 2022. In addition, each record has associated information such as the sampling location (89%), collector and person who identified the species (64%), date of the capture (54%) and plant species where the bees were captured (20%). We believe that this database is the starting point to better understand and conserve bee biodiversity in the Iberian Peninsula

    Immune complexes in chronic Chagas disease patients are formed by exovesicles from Trypanosoma cruzi carrying the conserved MASP N-terminal region

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    The exovesicles (EVs) are involved in pathologic host-parasite immune associations and have been recently used as biomarkers for diagnosis of infectious diseases. The release of EVs by Trypanosoma cruzi, the causative agent of Chagas disease, has recently been described, with different protein cargoes including the MASP multigene family of proteins MASPs are specific to this parasite and characterized by a conserved C-terminal (C-term) region and an N-terminal codifying for a signal peptide (SP). In this investigation, we identified immature MASP proteins containing the MASP SP in EVs secreted by the infective forms of the parasite. Those EVs are responsible for the formation of immune complexes (ICs) containing anti-MASP SP IgGs in patients with different (cardiac, digestive and asymptomatic) chronic Chagas disease manifestations. Moreover, purified EVs as well as the MASP SP inhibit the action of the complement system and also show a significant association with the humoral response in patients with digestive pathologies. These findings reveal a new route for the secretion of MASP proteins in T. cruzi, which uses EVs as vehicles for immature and misfolded proteins, forming circulating immune complexes. Such complexes could be used in the prognosis of digestive pathologies of clinical forms of Chagas disease.Fil: Díaz Lozano, Isabel María. Universidad de Granada; EspañaFil: De Pablos, Luis Miguel. Universidad de Granada; España. University Of York;Fil: Longhi, Silvia Andrea. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Zago, María Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires; ArgentinaFil: Osuna, Antonio. Universidad de Granada; Españ

    Impact of Dynamic Capabilities on Customer Satisfaction through Digital Transformation in the Automotive Sector

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    Technology has impacted businesses in different areas, and, consequently, many companies have found it necessary to make changes in their structures and business models to improve customer satisfaction. The objective was to quantify the effect of dynamic capabilities on customer satisfaction, through digital transformation within the automotive sector. A random sample of 42 questionnaires on 127 surveyed industries was collected during the period 2019–2020 in a pre-COVID-19 context. A structural equation model (SEM) in two stages was applied. In the first stage, two reflective models were built. In a second stage, a structural equation model was evaluated. The results obtained in this study showed that the capabilities of sensing, seizing and innovation were suitably grouped in a construct called “Dynamic Capabilities”. A positive influence of Dynamic Capabilities on customer satisfaction was found. Therefore, the companies in this industry should focus on developing dynamic capabilities to improve customer satisfaction. Once the opportunities have been identified, managers take advantage of their potential (seizing) to transform and exploit knowledge in the creation, innovation, process improvement, and definition of strategies to combine new knowledge with that already existing. The digital transformation has contributed to identify the real needs for customers, to contact them and solve their problems, as well as offering products and services by anticipating their needs

    Peranan Program Remidial dalam Meningkatkan Efektivitas dan Efisiensi Belajar

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    Adalah suatu realita bahwa dalam proses belajar mengajar terdapat perbedaan-perbedaan pada diri siswa, baik yang berasal dari faktor-faktor internal maupun eksternal. Perbedaan perbedaan itu antara lain dalam hal : Waktu dan irama perkembanganMotif, inteligensi dan emosiKecakapan menangkap pelajaranPembawaanLingkungan Dengan perbedaan-perbedaan itu akan dihasilkan tingkat penguasaan belajar yang berbeda-beda pula. Ini berarti bahwa dalam pelaksanaan proses belajar-mengajar itu ada siswa-siswa yang cepat dan berhasil mencapai tujuan instruksional yang hendak dicapai. Namun sebaliknya ada pula siswa-siswa yang lambat dan menemui kesulitan dalam mencapai tujuan instruksional itu. Untuk memberikan pelayanan kepada individu siswa dan tingkat keberhasilannya yang berbeda-beda, maka proses belajar mengajar di sekolah-sekolah kita selain berorientasi kepada tujuan instruksional yang hendak dicapai, juga berorientasi kepada prinsip belajar tuntas. Khusus untuk melayani siswa yang lamban, menemui kesulitan dalam mencapai tujuan isntruksional, maka dilaksanakan program remedial dalam proses belajar-mengajar. Dengan program remedial itu diharapkan semua siswa yang mengalami kesulitan belajar dapat ditolong, sehingga tak ada seorang pun dari seluruh populasi siswa yang tidak berhasil dalam mencapai tujuan instruksional yang di tentukan. Dengan demikian berarti bahwa dilaksanakannya program dalam proses belajar-mengajar akan meningkatkan efektivitas dan efisiensi belajar

    The effect of bending on laser-cut electro-textile inductors and capacitors attached on denim as wearable structures

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    In this paper we present the design, fabrication and characterization of electro-textile inductor and capacitor patterns on denim fabric as a basis for the development of wearable e-textiles. Planar coil inductors have been harnessed as antenna structures for the development of Near Field Communication (NFC) tags with temperature sensing capability, while interdigitated electrode (IDE) capacitors have been used as humidity sensors for wearable applications. The effect of bending in the electrical performance of such structures was evaluated, showing variations below 5% in both inductance and capacitance values for bending angles in the range of interest, i.e. those fitting to human limbs. In the case of the fabricated NFC tags, a shift in the resonance frequency below 1.7% was found, meaning that the e-textile tag would still be readable by an NFC- enabled smartphone. In respect of the capacitive humidity sensor, we obtained a minimum capacitance variation of 40% for a relative humidity range from 10% to 90%. Measured thermal shift was below 5% in the range from 10 to 40oC. When compared to the 4% variation due to bending, it can be concluded that this capacitive structure can be harnessed as humidity sensor even under bending strain conditions and moderate temperature variations. The development and characterization of such structures on denim fabrics, which is one of the most popular fabrics for everyday clothing, combined with the additional advantage of affordable and easy fabrication methodologies, means a further step towards the next generation of smart e-textile products

    Neuromelanin activates proinflammatory microglia through a caspase-8-dependent mechanism

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    Background We have uncovered a caspase-dependent (caspase-8/caspase-3/7) signaling governing microglia activation and associated neurotoxicity. Importantly, a profuse non-nuclear activation of cleaved caspases 8 and 3 was found in reactive microglia in the ventral mesencephalon from subjects with Parkinson’s disease, thus supporting the existence of endogenous factors activating microglia through a caspase-dependent mechanism. One obvious candidate is neuromelanin, which is an efficient proinflammogen in vivo and in vitro and has been shown to have a role in the pathogenesis of Parkinson’s disease. Consequently, the goal of this study is to test whether synthetic neuromelanin activates microglia in a caspase-dependent manner. Results We found an in-vivo upregulation of CD16/32 (M1 marker) in Iba1-immunolabeled microglia in the ventral mesencephalon after neuromelanin injection. In vitro experiments using BV2 cells, a microglia-derived cell line, demonstrated that synthetic neuromelanin induced a significant chemotactic response to BV2 microglial cells, along with typical morphological features of microglia activation, increased oxidative stress and induction of pattern-recognition receptors including Toll-like receptor 2, NOD2, and CD14. Analysis of IETDase (caspase-8) and DEVDase (caspase-3/7) activities in BV2 cells demonstrated a modest but significant increase of both activities in response to neuromelanin treatment, in the absence of cell death. Conclusions Caspase-8 inhibition prevented typical features of microglia activation, including morphological changes, a high rate of oxidative stress and expression of key proinflammatory cytokines and iNO

    Spatio-temporal activation of caspase-8 in myeloid cells upon ischemic stroke

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    Ischemic stroke (caused by thrombosis, embolism or vasoconstriction) lead to the recruitment and activation of immune cells including resident microglia and infiltrating peripheral macrophages, which contribute to an inflammatory response involved in regulation of the neuronal damage. We showed earlier that upon pro-inflammatory stimuli, the orderly activation of caspase-8 and caspase-3/7 regulates microglia activation through a protein kinase C-δ dependent pathway. Here, we present in vivo evidence for the activation of caspase-8 and caspase-3 in microglia/macrophages in post-mortem tissue from human ischemic stroke subjects. Indeed, CD68-positive microglia/macrophages in the ischemic peri-infarct area exhibited significant expression of the cleaved and active form of caspase-8 and caspase-3. The temporal and spatial activation of caspase-8 was further investigated in a permanent middle cerebral artery occlusion mouse model of ischemic stroke. Increasing levels of active caspase-8 was found in Iba1-positive cells over time in the peri-infarct area, at 6, 24 and 48 h after artery occlusion. Analysis of post-mortem brain tissue from human subject who suffered two stroke events, referred as recent and old stroke, revealed that expression of cleaved caspase-8 and -3 in CD68-positive cells could only be found in the recent stroke area. Analysis of cleaved caspase-8 and -3 expressions in a panel of human stroke cases arranged upon days-after stroke and age-matched controls suggested that the expression of these caspases correlated with the time of onset of stroke. Collectively, these data illustrate the temporal and spatial activation of caspase-8 and -3 in microglia/macrophages occurring upon ischemic stroke and suggest that the expression of these caspases could be used in neuropathological diagnostic wor

    Promastigote EPS secretion and haptomonad biofilm formation as evolutionary adaptations of trypanosomatid parasites for colonizing honeybee hosts

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    Bees are major pollinators involved in the maintenance of all terrestrial ecosystems. Biotic and abiotic factors placing these insects at risk is a research priority for ecological and agricultural sustainability. Parasites are one of the key players of this global decline and the study of their mechanisms of action is essential to control honeybee colony losses. Trypanosomatid parasites and particularly the Lotmaria passim are widely spread in honeybees, however their lifestyle is poorly understood. In this work, we show how these parasites are able to differentiate into a new parasitic lifestyle: the trypanosomatid biofilms. Using different microscopic techniques, we demonstrated that the secretion of Extracellular Polymeric Substances by free-swimming unicellular promastigote forms is a prerequisite for the generation and adherence of multicellular biofilms to solid surfaces in vitro and in vivo. Moreover, compared to human-infective trypanosomatid parasites our study shows how trypanosomatid parasites of honeybees increases their resistance and thus resilience to drastic changes in environmental conditions such as ultralow temperatures and hypoosmotic shock, which would explain their success thriving within or outside their hosts. These results set up the basis for the understanding of the success of this group of parasites in nature and to unveil the impact of such pathogens in honeybees, a keystones species in most terrestrial ecosystems.Spanish Programme for Knowledge Generation and Scientific and Technological Strengthening of the R+D+I System, grant PID2021-126938OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF/EU"Grant PGC2018-098929-A-I00 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe"Maria Zambrano postdoctoral fellowship program of the Spanish Ministry of Science, Innovation and Universities (RD289/2021)Doctoral Program in Fundamental and Systems Biology (University of Granada, UGR

    Expectativas, necesidades y oportunidades de los maestros en formación ante la enseñanza de las ciencias en la Educación Primaria

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    Este trabajo presenta los resultados del análisis de varias encuestas realizadas en tres momentos clave de la formación de maestros en relación con la didáctica de las ciencias experimentales. Antes de iniciar las asignaturas, las expectativas formativas están fuertemente condicionadas por la visión de la especialidad elegida. Entre las necesidades reales destacan los contenidos teóricos de ciencias, aunque muchos estudiantes señalan también el aprendizaje de estrategias didácticas. Al finalizar las asignaturas, los maestros en formación señalan la importancia de muchos más aspectos de los previstos inicialmente por ellos, dejando al margen los aspectos teóricos de ciencias. Finalmente, tras el prácticum, muchos maestros en formación aseguran que todo lo anterior tiene poca aplicación en el aula y manifiestan las escasas oportunidades que tienen para poner en práctica lo aprendido en la universidad.This paper presents the results of the analysis of several surveys conducted in three key moments in the training of teachers regarding science education. Before starting the courses, training expectations are heavily influenced by the vision of the chosen specialty. Among the real needs they include the theoretical contents of science, although many students reported their preferences for learning about teaching strategies. Upon completion of the courses, training teachers point out the importance of many more aspects than originally planned, leaving aside the theoretical aspects of science. Finally, after the practicum, many pre-service teachers say that all this has little application in the classroom and show the limited opportunities to implement what they learned in university
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