2,041 research outputs found

    Visual awareness negativity and P3: ERP study of the distinctive neural correlates of conscious vision

    Get PDF
    This research aimed to replicate the previous findings of Koivisto & Grassini (2016). Using event-related potentials (ERPs), we studied the neural correlates of visual consciousness. Specifically, we wanted to study visual awareness negativity, that has been reported as the first ERP correlate of consciousness as its latency seems to be fast enough to be the neural correlate of the phenomenal consciousness, which could be the earliest manifestation of consciousness. We also studied the late positivity, that seems to reflect the cognitive components of the reflective consciousness, as it involves the voluntary operations performed with the object like identify it or recognize it. Surprisingly, and despite the previously reported in literature, in this study we did not observe visual awareness negativity, but found that only late positivity correlated with conscious perception. We conclude that our results do not support the hypothesis about VAN as the correlate of phenomenal consciousness, whilst our observations regarding P3 appear to support the hypothesis about reflective consciousness occurring in this period. We interpret these findings as possibly affected by a different statistical analysis. Also, the fact that phenomenal consciousness can be understood in various ways may lead to contradictory findings. However, more research is necessary to find alternative explanations to our findings as well as other experimental approaches to the study of neural correlates of consciousness

    Breaking the spell of nestedness: The entropic origin of nestedness in mutualistic systems

    Get PDF
    Mutualistic interactions, those that are naturally beneficial for both interacting species, are recurrently found in ecosystems. Observations of natural systems show that if we draw mutualistic relationships as links between species, the resulting mutualistic network of interactions displays a widespread particular ordering called nestedness. In such an ordering, the mutualistic partners of a given species conform a subset of the partners of all species with larger degree, that is, of those species having more interactions. On the other hand, theoretical works show that a nested structure has a positive impact on a number of relevant features of mutualistic communities ranging from species coexistence to structural stability and biodiversity. However, how nestedness emerges and what are its determinants, are still open challenges that have led to multiple debates to date. Here we show, by applying a theoretical approach to the analysis of 167 real mutualistic networks, that nestedness is not an irreducibly macroscopic feature but an entropic consequence of the degree sequences (number of mutualistic interactions of each species). Remarkably, we find that an outstanding majority of the analyzed networks does not show statistically significant nestedness. These findings point to the need of revising previous claims about the role of nestedness and might contribute to expand our understanding of how evolution shapes mutualistic interactions and communities by placing the focus on the node-dependent properties rather than on global quantities

    Regulation of MT1-MMP Activity through Its Association with ERMs

    Get PDF
    Membrane-bound proteases play a key role in biology by degrading matrix proteins or shedding adhesion receptors. MT1-MMP metalloproteinase is critical during cancer invasion, angiogenesis, and development. MT1-MMP activity is strictly regulated by internalization, recycling, autoprocessing but also through its incorporation into tetraspanin-enriched microdomains (TEMs), into invadopodia, or by its secretion on extracellular vesicles (EVs). We identified a juxtamembrane positively charged cluster responsible for the interaction of MT1-MMP with ERM (ezrin/radixin/moesin) cytoskeletal connectors in breast carcinoma cells. Linkage to ERMs regulates MT1-MMP subcellular distribution and internalization, but not its incorporation into extracellular vesicles. MT1-MMP association to ERMs and insertion into TEMs are independent phenomena, so that mutation of the ERM-binding motif in the cytoplasmic region of MT1-MMP does not preclude its association with the tetraspanin CD151, but impairs the accumulation and coalescence of CD151/MT1-MMP complexes at actin-rich structures. Conversely, gene deletion of CD151 does not impact on MT1-MMP colocalization with ERM molecules. At the plasma membrane MT1-MMP autoprocessing is severely dependent on ERM association and seems to be the dominant regulator of the enzyme collagenolytic activity. This newly characterized MT1-MMP/ERM association can thus be of relevance for tumor cell invasion.This work has been supported by grants BFU2014-55478-R, REDIEX. SAF2015-71231-REDT and BIO2017-86500-R from Ministerio Español de Economía y Competitividad (MINECO) and by a grant from Fundación Ramón Areces “Ayudas a la Investigación en Ciencias de la Vida y de la Materia, 2014” to M.Y.-M. H.S. was supported by a FPI-UAM fellowship. The CNIC is supported by the Ministry of Ciencia, Innovacion y Universidades and the Pro CNIC Foundation, is a Severo Ochoa Center of Excellence (SEV-2015-0505), also supported by European Regional Development Fund (FEDER) “Una manera de hacer Europa”.S

    Huellas de la presencia pasada de pinares montanos en la submeseta norte de la Península Ibérica: Tubilla del Lago y Tubilla del Agua

    Get PDF
    Se presentan los resultados de los estudios de macrorrestos e impresiones vegetales hallados en dos localidades de la submeseta norte de la Península Ibérica. Los troncos y piñas subfósiles extraídos en las obras de la turbera de Tubilla del Lago (Burgos), así como el molde de piña encontrado en los travertinos de Tubilla del Agua (Burgos), han sido identificados mediante morfología comparada con apoyo de la microtomía en el caso de las maderas. Los restos subfósiles han sido datados mediante 14 C mientras que la antigüedad del molde ha sido deducida por su posición en el edificio travertínico y la edad del mismo, en base al conocimiento de la cronología de la génesis de este tipo de estructuras. Los resultados indican la presencia holocena de Pinus nigra Arnold en ambas localidades. Estas evidencias se suman a otras paleobotánicas, históricas y toponímicas ya existentes, que reflejan una mayor extensión de esta especie en la submeseta norte anterior a la generalización de la alteración antrópica del paisaj

    Generalidades de la farmacovigilancia

    Get PDF
    La farmacovigilancia es un área de vital importancia en la salud de la comunidad, la cual tiene como objetivo principal vigilar la seguridad y eficacia de los medicamentos. Para lograr estos estudios se debe contar con la participación de pacientes, médicos, farmacéuticos secretarias de salud y hospitales quienes se encargan de reportar las reacciones adversas el uso inapropiado y las posibles complicaciones que se generaron al usar un medicamento en específico. Los eventos o reacciones adversas son definidas como cualquier suceso medico desafortunado que se puede presentar durante un tratamiento con un medicamento, pero no siempre se relaciona con el mismo, por esta misma razón la farmacovigilancia tiene como objetivo principal realizar la vigilancia después de que estos son comercializados y dados al público para su uso y administración, y así poder determinar la seguridad, efectividad y errores de medicación asociados con el mismo, Por lo consiguiente a continuación veremos esto más al detalle.Pharmacovigilance is an area of vital importance in the health of the community, whose main objective is to monitor the safety and efficacy of medicines. To achieve these studies, it is necessary to have the participation of patients, doctors, pharmacists, health secretaries and hospitals who are responsible for reporting adverse reactions, inappropriate use and possible complications that are generated when using a specific medication. Adverse events or reactions are defined as any unfortunate medical event that can occur during treatment with a medication, but is not always related to it, for this same reason pharmacovigilance has as its main objective to monitor after these are marketed and given to the public for its use and administration, and thus be able to determine the safety, effectiveness and medication errors associated with it, therefore, we will see this in more detail below

    Dimensioning Optimization of the Permanent Magnet Synchronous Generator for Direct Drive Wind Turbines

    Get PDF
    In the present work, a methodology that allows optimizing the permanent magnet synchronous generator (PMSG) design by establishing limit values of magnet radius and length that maximize efficiency for the nominal parameters of the wind turbine is developed. The methodology consists of two fundamental models. One model calculates the generator parameters from the radius of the magnet base, and the other optimization model determines two optimum generators according to the optimization criteria of maximum efficiency and maximum efficiency with minimum weight starting from the axial length and the radius of the magnet base. For the optimization, the numerical method of the golden section was used. The model was validated from a 10 kW PMSG and the results of two optimum generators are presented according to the optimization criteria. In addition, when the obtained results are compared with the reference electric generator, an increase in efficiency of 1.15% and 0.81% and a reduction in weight of 30.79% and 39.15% of the optimized generators are obtained for maximum efficiency and minimum weight, respectively. Intermediate options between the maximum efficiency generator and the minimum weight generator allows for the selection of the optimum dimensioning for the electric generator as a function of the parameters from the wind turbine design

    Investigaciones paleobotánicas en la cuenca central del Duero

    Full text link
    El objetivo del trabajo es dar a conocer el estado actual de conocimientos científicos sobre el pasado del paisaje vegetal (Cuaternario final) en los territorios interiores no montanos de la depresión del Duero. Se recogen todos los yacimientos cuyo estudio ya ha concluido así como los que se encuentran en fase de investigación o prospección. Se precisa el tipo de informador en cada caso (polen, carbones, maderas, otros macrorrestos), el rango cronológico conocido hasta el momento así como el grado o proporción de trabajo realizado en cada yacimiento en relación con las previsiones efectuadas. Se aporta una síntesis-resumen de los principales resultados obtenidos hasta el momento y de los aspectos más concluyentes de los mismos en relación con la elaboración de modelos de evolución del paisaje vegetal posteriores al último máximo glacial en la Meseta norte. A nuestro juicio debe destacarse, como uno de los resultados más relevantes, el conocimiento ya afianzado de que los pinares de meseta han sido el elemento más significativo en amplios sectores del sur y este de la cuenca a lo largo de todo o gran parte del Holoceno, circunstancia que contrasta con todas las propuestas de paisaje pretérito (preantrópico) existentes antes de la realización de las prospecciones paleobotánicas

    Barefoot vs common footwear:A systematic review of the kinematic, kinetic and muscle activity differences during walking

    Get PDF
    Habitual footwear use has been reported to influence foot structure with an acute exposure being shown to alter foot position and mechanics. The foot is highly specialised thus these changes in structure/position could influence functionality. This review aims to investigate the effect of footwear on gait, specifically focussing on studies that have assessed kinematics, kinetics and muscle activity between walking barefoot and in common footwear. In line with PRISMA and published guidelines, a literature search was completed across six databases comprising Medline, EMBASE, Scopus, AMED, Cochrane Library and Web of Science. Fifteen of 466 articles met the predetermined inclusion criteria and were included in the review. All articles were assessed for methodological quality using a modified assessment tool based on the STROBE statement for reporting observational studies and the CASP appraisal tool. Walking barefoot enables increased forefoot spreading under load and habitual barefoot walkers have anatomically wider feet. Spatial-temporal differences including, reduced step/stride length and increased cadence, are observed when barefoot. Flatter foot placement, increased knee flexion and a reduced peak vertical ground reaction force at initial contact are also reported. Habitual barefoot walkers exhibit lower peak plantar pressures and pressure impulses, whereas peak plantar pressures are increased in the habitually shod wearer walking barefoot. Footwear particularly affects the kinematics and kinetics of gait acutely and chronically. Little research has been completed in older age populations (50+ years) and thus further research is required to better understand the effect of footwear on walking across the lifespan

    Grupo español de cirugía torácica asistida por videoimagen: método, auditoría y resultados iniciales de una cohorte nacional prospectiva de pacientes tratados con resecciones anatómicas del pulmón

    Full text link
    Introduction: our study sought to know the current implementation of video-assisted thoracoscopic surgery (VATS) for anatomical lung resections in Spain. We present our initial results and describe the auditing systems developed by the Spanish VATS Group (GEVATS). Methods: we conducted a prospective multicentre cohort study that included patients receiving anatomical lung resections between 12/20/2016 and 03/20/2018. The main quality controls consisted of determining the recruitment rate of each centre and the accuracy of the perioperative data collected based on six key variables. The implications of a low recruitment rate were analysed for '90-day mortality' and 'Grade IIIb-V complications'. Results: the series was composed of 3533 cases (1917 VATS; 54.3%) across 33 departments. The centres' median recruitment rate was 99% (25-75th:76-100%), with an overall recruitment rate of 83% and a data accuracy of 98%. We were unable to demonstrate a significant association between the recruitment rate and the risk of morbidity/mortality, but a trend was found in the unadjusted analysis for those centres with recruitment rates lower than 80% (centres with 95-100% rates as reference): grade IIIb-V OR=0.61 (p=0.081), 90-day mortality OR=0.46 (p=0.051). Conclusions: more than half of the anatomical lung resections in Spain are performed via VATS. According to our results, the centre's recruitment rate and its potential implications due to selection bias, should deserve further attention by the main voluntary multicentre studies of our speciality. The high representativeness as well as the reliability of the GEVATS data constitute a fundamental point of departure for this nationwide cohort

    Gasdermin B over-expression modulates HER2-targeted therapy resistance by inducing protective autophagy through Rab7 activation

    Get PDF
    Gasdermin B (GSDMB) over-expression promotes poor prognosis and aggressive behavior in HER2 breast cancer by increasing resistance to therapy. Decoding the molecular mechanism of GSDMB-mediated drug resistance is crucial to identify novel effective targeted treatments for HER2/GSDMB aggressive tumors. Different in vitro approaches (immunoblot, qRT-PCR, flow cytometry, proteomic analysis, immunoprecipitation, and confocal/electron microscopy) were performed in HER2 breast and gastroesophageal carcinoma cell models. Results were then validated using in vivo preclinical animal models and analyzing human breast and gastric cancer samples. GSDMB up-regulation renders HER2 cancer cells more resistant to anti-HER2 agents by promoting protective autophagy. Accordingly, the combination of lapatinib with the autophagy inhibitor chloroquine increases the therapeutic response of GSDMB-positive cancers in vitro and in zebrafish and mice tumor xenograft in vivo models. Mechanistically, GSDMB N-terminal domain interacts with the key components of the autophagy machinery LC3B and Rab7, facilitating the Rab7 activation during pro-survival autophagy in response to anti-HER2 therapies. Finally, we validated these results in clinical samples where GSDMB/Rab7/LC3B co-expression associates significantly with relapse in HER2 breast and gastric cancers. Our findings uncover for the first time a functional link between GSDMB over-expression and protective autophagy in response to HER2-targeted therapies. GSDMB behaves like an autophagy adaptor and plays a pivotal role in modulating autophagosome maturation through Rab7 activation. Finally, our results provide a new and accessible therapeutic approach for HER2/GSDMB + cancers with adverse clinical outcome. The online version contains supplementary material available at 10.1186/s13046-022-02497-w
    corecore