692 research outputs found

    Polycomb proteins in mammalian cell differentiation and plasticity

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    During development cell differentiation is accompanied by progressive restriction of the developmental potential and increased structural and functional specialization of cells. In this context, mechanisms of cell memory guarantee that cells maintain different identities previously determined by the integrated action of signalling and specific sets of transcription factors. Unraveling the molecular basis by which cells build and maintain their memory represents one of the most fascinating problems in biology. PcG proteins were originally identified as part of an epigenetic cellular memory system that controls gene silencing via chromatin structure. However, recent reports suggest that they are also involved in controlling dynamics and plasticity of gene regulation, particularly during differentiation, by interacting with other components of the transcriptional apparatus. In this review, we discuss the role of PcG proteins in pluripotent ES cells and in well known mammalian cell differentiation systems including skeletal muscle, epidermal, neuronal differentiation. The emerging picture suggests that indeed, plasticity and not rigidity is a fundamental aspect of PcG physiology and cell memory function

    Evaluation of the use and managing of the ICT in the teachers in higher education. A Mexican case.

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    Con el propósito de poner en marcha una innovación sobre tecnologías de la información y la comunicación (TIC) en la docencia de una universidad mexicana, se emprendió una investigación de corte cualitativo (fundamentación pedagógica del trabajo de la Universidad, cuestionario de opinión, observación participante en los procesos de formación en equipo emprendidos) para identificar usos de las TIC (nivel de formación del profesorado, ámbitos de uso, opinión sobre su repercusión en su actividad docente, metodología en que se aplica, apoyo institucional con que se cuenta y temáticas de formación en TIC ), y resultados tras un proceso de formación en el centro, comparados con los obtenidos en otros centros universitarios mexicanos. Entre los resultados del estudio, aún en su fase exploratoria, cabe destacar que el nivel de formación de los docentes universitarios en TIC es bajo, los ámbitos de su uso son la preparación de clases y el correo electrónico, que los docentes creen que las TIC modificarán considerablemente su actividad docente, pero no tienen claro en qué sentido; que desconocen metodologías que incorporan TIC; que conocen en general los apoyos institucionales con que se cuenta en su Universidad para hacer uso de las TIC; que la formación que ofrece la Universidad sobre TIC es genérica, de manejo de herramientas, y no hay consideraciones de su uso pedagógico, y que se hace en procesos que no toman en cuenta el trabajo colegiado en la docencia. Sobre el proceso de formación en equipo para el desarrollo discutido y acordado por los docentes de una metodología propia que integra las TIC se puede avanzar que se ha puesto en marcha con enormes dificultades, aunque tiene buena acogida entre los docentes de esta Universidad mexicana.With the aim of innovate with ICT the courses that offer an Mexican university,a qualitative research was undertaken (pedagogical foundation of its work, a survey questionnaire, participant observation of teacher team work in México) to identify uses of the ICT (staff training, computer uses, opinion on its repercussion in its educational activity, methodology in which is applied, institutional support and ICT subject), and results after a training process. It offers as results that students use of ICT is low, teacher uses are class planning and electronic mail, every people think that the ICT will modify considerably their educational activity, but do not know clearly in what sense; that they do not know methodologies that incorporate ICT; that the institutional supports are well known; that the training on ICT is not specific. On the process of training throughout teamwork, it has started up with enormous difficulties

    Generalized Inpainting Method for Hyperspectral Image Acquisition

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    A recently designed hyperspectral imaging device enables multiplexed acquisition of an entire data volume in a single snapshot thanks to monolithically-integrated spectral filters. Such an agile imaging technique comes at the cost of a reduced spatial resolution and the need for a demosaicing procedure on its interleaved data. In this work, we address both issues and propose an approach inspired by recent developments in compressed sensing and analysis sparse models. We formulate our superresolution and demosaicing task as a 3-D generalized inpainting problem. Interestingly, the target spatial resolution can be adjusted for mitigating the compression level of our sensing. The reconstruction procedure uses a fast greedy method called Pseudo-inverse IHT. We also show on simulations that a random arrangement of the spectral filters on the sensor is preferable to regular mosaic layout as it improves the quality of the reconstruction. The efficiency of our technique is demonstrated through numerical experiments on both synthetic and real data as acquired by the snapshot imager.Comment: Keywords: Hyperspectral, inpainting, iterative hard thresholding, sparse models, CMOS, Fabry-P\'ero

    Optimal Setting of Earthquake-Related Ionospheric TEC (Total Electron Content) Anomalies Detection Methods: Long-Term Validation over the Italian Region

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    Over the last decade, thanks to the availability of historical satellite observations that have begun to be significantly large and thanks to the exponential growth of artificial intelligence techniques, many advances have been made in the detection of geophysical parameters such as seismic-related anomalies. In this study, the variations of the ionospheric Total Electron Content (TEC), one of the main parameters historically proposed as a seismic-connected indicator, are analyzed. To make a statistically robust analysis of the complex phenomena involved, we propose a completely innovative machine-learning approach developed in the R programming language. Through this approach, an optimal setting of the multitude of methodological inputs currently proposed for the detection of ionospheric anomalies is performed. The setting is optimized by analyzing, for the first time, multi-year—mostly twenty-year—time series of TEC satellite data measured by global navigation satellite systems (GNSS) over the Italian region, matched with the corresponding multi-year time series of seismic events. Seismic events including all the countries of the Mediterranean area, up to Turkey, are involved in the analysis. Tens of thousands of possible combinations of input methodological parameters are simulated and classified according to pre-established criteria. Several inputs examined return clear results. These results combined with each other highlight the presence of anomalous seismic-related sequences that have an extremely low probability of having been detected randomly (up to 2 out of 1 million). The anomalies identified represent the most anomalous behaviors of the TEC recorded during the entire period under investigation (e.g., 20 years). Some of the main conclusions are that, at mid-latitudes, ① the detection of seismic-TEC anomalies can be more efficient looking for punctual rather than persistent phenomena; ② the optimal thresholds for the identification of co-seismic anomalies can assume different values depending on type of anomaly (positive or negative) and type of observation; ③ single GNSS receiver data can be useful for capturing local earthquake-ionospheric effects and Global Ionospheric Maps (GIM) data can be functional in detecting large-scale earthquake-ionospheric effects; ④ earthquakes deeper than 50 km are less likely to affect the ionosphere

    Investigational drugs for the treatment of endometriosis, an update on recent developments

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    Introduction: Endometriosis is a hormone-dependent benign chronic disease that requires a chronic medical therapy. Although currently available drugs are efficacious in treating endometriosis-related pain, some women experience partial or no improvement. Moreover, the recurrence of symptoms is expected after discontinuation of the therapies. Currently, new drugs are under intense clinical investigation for the treatment of endometriosis. Areas covered: This review aims to offer the reader a complete and updated overview on new investigational drugs and early molecular targets for the treatment of endometriosis. The authors describe the pre-clinical and clinical development of these agents. Expert opinion: Among the drugs under investigation, late clinical trials on gonadotropin-releasing hormone antagonists (GnRH-ant) showed the most promising results for the treatment of endometriosis. Aromatase inhibitors (AIs) are efficacious in treating endometriosis related pain symptoms but they cause significant adverse effects that limit their long-term use. New targets have been identified to produce drugs for the treatment of endometriosis, but the majority of these new compounds have only been investigated in laboratory studies or early clinical trials. Thus, further clinical research is required in order to elucidate their efficacy and safety in human

    From visual comparison to robust satellite techniques: 30 years of thermal infrared satellite data analyses for the study of earthquake preparation phases

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    This review paper reports the main contributions and results achieved after more than 30 years of studies on the possible relationships among space-time variation of Earth’s thermally emitted radiation, measured by satellite sensors operating in the Thermal InfraRed (TIR) spectral range (8-14 m), and earthquake occurrence. Focus will be given on the different existing methods/models to: 1) discriminate a possible pre-seismic TIR anomaly from all the other TIR signal fluctuations; 2) correlate such anomalies with space, time and magnitude of earthquakes; 3) physically justify such a correlation

    Landslides Detection and Mapping with an Advanced Multi-Temporal Satellite Optical Technique

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    Landslides are catastrophic natural phenomena occurring as a consequence of climatic, tectonic, and human activities, sometimes combined among them. Mostly due to climate change effects, the frequency of occurrence of these events has quickly grown in recent years, with a consequent increase in related damage, both in terms of loss of human life and effects on the involved infrastructures. Therefore, implementing properly actions to mitigate consequences from slope instability is fundamental to reduce their impact on society. Satellite systems, thanks to the advantages offered by their global view and sampling repetition capability, have proven to be valid tools to be used for these activities in addition to traditional techniques based on in situ measurements. In this work, we propose an advanced multitemporal technique aimed at identifying and mapping landslides using satellite-derived land cover information. Data acquired by the Multispectral Instrument (MSI) sensor aboard the Copernicus Sentinel-2 platforms were used to investigate a landslide affecting Pomarico city (southern Italy) in January 2019. Results achieved indicate the capability of the proposed methodology in identifying, with a good trade-off between reliability and sensitivity, the area affected by the landslide not just immediately after the event, but also a few months later. The technique was implemented within the Google Earth Engine Platform, so that it is completely automatic and could be applied everywhere. Therefore, its potential for supporting mitigation activities of landslide risks is evident

    RST Analysis of Anomalous TIR Sequences in Relation with Earthquakes Occurred in Turkey in the Period 2004–2015

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    first_pagesettings Open AccessArticle RST Analysis of Anomalous TIR Sequences in Relation with Earthquakes Occurred in Turkey in the Period 2004–2015 by Carolina Filizzola 1ORCID,Angelo Corrado 2,Nicola Genzano 2ORCID,Mariano Lisi 1ORCID,Nicola Pergola 1ORCID,Roberto Colonna 2 andValerio Tramutoli 2,*ORCID 1 Institute of Methodologies for Environmental Analysis, National Research Council, 85050 Potenza, Italy 2 School of Engineering, University of Basilicata, 85100 Potenza, Italy * Author to whom correspondence should be addressed. Academic Editor: Stephan Havemann Remote Sens. 2022, 14(2), 381; https://doi.org/10.3390/rs14020381 Received: 12 November 2021 / Revised: 8 January 2022 / Accepted: 11 January 2022 / Published: 14 January 2022 (This article belongs to the Special Issue Advances in Remote Sensing Systems for Disaster Management and Risk Mitigation) Download PDF Browse Figures Citation Export Abstract The paper provides, for the first time, a long-term (>10 years) analysis of anomalous transients in Earth’s emitted radiation over Turkey and neighbouring regions. The RST (Robust Satellite Techniques) approach is used to identify Significant Sequences of Thermal Anomalies (SSTAs) over about 12 years (May 2004 to October 2015) of night-time MSG-SEVIRI satellite images. The correlation analysis is performed with earthquakes with M ≥ 4, which occurred in the investigated period/region within a pre-defined space-time volume around SSTA occurrences. It confirms, also for Turkey, the possibility to qualify SSTAs among the candidate parameters of a multi-parametric system for time-Dependent Assessment of Seismic Hazard (t-DASH). After analysing about 4000 images (about 400 million of single satellite records), just 155 SSTAs (about 4 every 100 images) were isolated; 115 (74% out of the total) resulted in earthquake-related (false-positive rate 26%). Results of the error diagram confirms a non-casual correlation between RST-based SSTAs and earthquake occurrences, with probability gain values up to 2.2 in comparison with the random guess. The analysis, separately performed on Turkish areas characterized by different faults and earthquakes densities, demonstrates the SSTA correlation with a dynamic seismicity more than with static tectonic settings

    Transvaginal ultrasonography with vs without bowel preparation in the diagnosis of rectosigmoid endometriosis: prospective study

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    Objectives: The primary aim of this study was to compare the diagnostic accuracy of transvaginal sonography (TVS) with vs without bowel preparation (BP) in detecting the presence of rectosigmoid endometriosis. Secondary objectives were to compare the diagnostic accuracy of the two techniques in estimating infiltration of the submucosa, length of the largest rectosigmoid nodules, distance of the nodules from the anal verge and presence of multifocal disease. Methods: This was a prospective study of patients with symptoms of pelvic pain for more than 6 months and/or suspicion of endometriosis referred to our institution between October 2016 and April 2018. Participants underwent a first TVS without BP followed by TVS with BP within a time interval of 1 week to 3 months. The examinations were performed independently and blindly by two sonographers. Only patients who underwent laparoscopy within the 6 months following the second ultrasound examination were included. Ultrasound results using the two techniques were compared with surgical and histological findings. Results: Of the 262 patients included in the study, 118 had rectosigmoid endometriosis confirmed at surgery. There was no significant difference in accuracy between TVS with and that without BP in diagnosing the presence of rectosigmoid endometriosis (93.5% vs 92.3%; P = 0.453). No significant difference was observed in accuracy between TVS with and that without BP in diagnosing submucosal infiltration (88.8% vs 84.6%; P = 0.238) and multifocal disease (97.2% vs 95.2%; P = 0.727) in patients diagnosed sonographically with rectosigmoid endometriosis. The accuracy of TVS with BP was similar to that of TVS without BP in estimating the maximum diameter of the largest nodule (P = 0.644) and the distance between the more caudal rectosigmoid nodule and the anal verge (P = 0.162). Conclusion: BP does not improve the diagnostic performance of TVS in detecting rectosigmoid endometriosis and in assessing characteristics of endometriotic nodules
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