882 research outputs found

    The key role of micrornas in self-renewal and differentiation of embryonic stem cells

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    Naïve pluripotent embryonic stem cells (ESCs) and epiblast stem cells (EpiSCs) represent distinctive developmental stages, mimicking the pre-and the post-implantation events during the embryo development, respectively. The complex molecular mechanisms governing the transition from ESCs into EpiSCs are orchestrated by fluctuating levels of pluripotency transcription factors (Nanog, Oct4, etc.) and wide-ranging remodeling of the epigenetic landscape. Recent studies highlighted the pivotal role of microRNAs (miRNAs) in balancing the switch from self-renewal to differentiation of ESCs. Of note, evidence deriving from miRNA-based reprogramming strategies underscores the role of the non-coding RNAs in the induction and maintenance of the stemness properties. In this review, we revised recent studies concerning the functions mediated by miRNAs in ESCs, with the aim of giving a comprehensive view of the highly dynamic miRNA-mediated tuning, essential to guarantee cell cycle progression, pluripotency maintenance and the proper commitment of ESCs

    Potential energy savings from circular economy scenarios based on construction and agri-food waste in Italy

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    In this study, our aim was to explore the potential energy savings obtainable from the recycling of 1 tonne of Construction and Demolition Waste (C&DW) generated in the Metropolitan City of Naples. The main fraction composing the functional unit are mixed C&DW, soil and stones, concrete, iron, steel and aluminium. The results evidence that the recycling option for the C&DW is better than landfilling as well as that the production of recycled aggregates is environmentally sustainable since the induced energy and environmental impacts are lower than the avoided energy and environmental impacts in the life cycle of recycled aggregates. This LCA study shows that the transition to the Circular Economy offers many opportunities for improving the energy and environmental performances of the construction sector in the life cycle of construction materials by means of internal recycling strategies (recycling C&DW into recycled aggregates, recycled steel, iron and aluminum) as well as external recycling by using input of other sectors (agri-food by-products) for the manufacturing of construction materials. In this way, the C&D sector also contributes to realizing the energy and bioeconomy transition by disentangling itself from fossil fuel dependence

    Magneto-seismic interpretation of subsurface volcanism in the Gaeta Gulf (Italy, Tyrrhenian Sea)

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    The occurrence of a former subaerial volcanic edifice off the Volturno River (Tyrrhenian Sea, Gulf of Gaeta) in the 41┬░N parallel is suggested by joint interpretation of multichannel seismic lines and ship-borne magnetic data. In the Campanian region igneous (volcanic) rocks are very close to the carbonate Mesozoic basement and seismics cannot always discriminate between them. A joint seismic-magnetic analysis was very effective in assessing the lithological nature of the bodies evidenced by both geophysical methods. Distortion analysis showed that the main magnetic source in the area is characterised by a not normal-polarity direction of the magnetization, similar to other Pleistocene volcanoes in the Tyrrhenian region. Hence we argued that the overall magmatic emplacement for this source occurred during a reverse-polarity chron, very likely the 0.78-1.78 Ma time span. This magnetically-derived time constraint is in agreement with seismic stratigraphy that shows that the entire volcano is sealed by the Volturno River prograding delta from Middle Pleistocene to Present in age. Our interpreted volcano belongs to a set of inferred onshore and offshore volcanic edifices all lying along the 41┬░N paralle

    Single-mode regime in large-mode-area rare-earth-doped rod-type PCFs

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    In this paper, large-mode-area, double-cladding, rare-earth-doped photonic crystal fibers are investigated in order to understand how the refractive index distribution and the mode competition given by the amplification can assure singlemode propagation. Fibers with different core diameters, i.e., 35,60, and 100 ╬╝m, are considered. The analysis of the mode effective index, overlap, effective area, gain, and power evolution along the doped fiber provides clear guidelines on the fiber physical characteristics to be matched in the fabrication process to obtain a truly or effectively single-mode output beam

    MicroRNA Roles in Cell Reprogramming Mechanisms

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    Cell reprogramming is a groundbreaking technology that, in few decades, generated a new paradigm in biomedical science. To date we can use cell reprogramming to potentially generate every cell type by converting somatic cells and suitably modulating the expression of key transcription factors. This approach can be used to convert skin fibroblasts into pluripotent stem cells as well as into a variety of differentiated and medically relevant cell types, including cardiomyocytes and neural cells. The molecular mechanisms underlying such striking cell phenotypes are still largely unknown, but in the last decade it has been proven that cell reprogramming approaches are significantly influenced by non-coding RNAs. Specifically, this review will focus on the role of microRNAs in the reprogramming processes that lead to the generation of pluripotent stem cells, neurons, and cardiomyocytes. As highlighted here, non-coding RNA-forced expression can be sufficient to support some cell reprogramming processes, and, therefore, we will also discuss how these molecular determinants could be used in the future for biomedical purposes

    Caratteristiche sismostratigrafiche di strutture sedimentarie diagnostiche dicorrenti di fondo nell\u2019off-shore del Golfo di Taranto.

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    L\u2019analisi integrata di dati multibeam e sismici ad altissima risoluzione (Chirp Sub-Bottom), acquisiti in un settore del Golfo di Taranto (Mare Ionio), ha permesso di identificare e classificare strutture sedimentarie diagnostiche di correnti di fondo (conturiti), formatesi nel tardo Quaternario. La classificazione proposta \ue8 basata sia su criteri sismo-stratigrafici che sulla comparazione con strutture analoge documentate da precedenti autori nei bacini oceanici [Faugeres et al., 1999 con rif.]. Nell\u2019area in esame sono stati identificati quattro settori (Alto dell\u2019Amendolara, Bacino di Corigliano, Bacino dell\u2019Amendolara ed Alto di Rossano-Cariati) caratterizzati da morfologia, pendenza e profondit\ue0 differente. Le strutture conturitiche sono state riconosciute prevalentemente nei settori NW e SE dell\u2019alto dell\u2019Amendolara, ad una profondit\ue0 compresa tra 130 m e 400 m e le geometrie interne ed esterne mostrano caratteristiche deposizionali ed erosive. Sono state classificate come sheeted drift le strutture sviluppate subparallelamente al profilo batimetrico, infill drift ed elongated drift le strutture caratterizzate da fosse ben sviluppate ed elementi erosivi quali fosse ed abraded surface. Sono stati osservati inoltre osservati sediment waves nel settore SW dell\u2019alto strutturale. Dall\u2019analisi integrata dei nuovi dati con quelli disponibili in letteratura \ue8 possibile ipotizzare che i fattori che hanno maggiormente influenzato tipologia, distribuzione areale e batimetrica dei depositi conturitici e degli elementi erosivi sono: a) morfologia del fondo marino; b) caratteristiche dei sedimenti (es. tessitura); c) variazione della velocit\ue0 della \u201cLevantine Intermediate Water come conseguenza delle d) variazioni eustatiche. Sono stati inoltre applicati in cascata i modelli bidimensionali CMS- Wave [Lin et al, 2006] per la propagazione dello spettro d\u2019onda, e CMS- Flow [Buttolph et al, 2006] per la circolazione interna, prendendo in considerazione i dati meteo marini forniti dall\u2019ECMWF nel punto di coordinate 39,5\ub0N, 17\ub0E, in modo da valutare le condizioni idrodinamiche in prossimit\ue0 del paraggio in esame. L\u2019integrazione dei dati indicati geologici/geofisici e dei risultati del codice di calcolo numerico ha permesso di ipotizzare un modello di circolazione della corrente \u201cLevantine Intermediate Water\u201d e valutare l\u2019influenza delle morfostrutture sulla circolazione delle acque profonde durante l\u2019ultima fase di abbassamento e stazionamento basso del livello del mare. Bibliografia Buttolph, A.,D., Reed, C.W., Kraus N., Wamsley, T.V., Ono, N., Larson, M.,Camenen, B., Hanson, H. Zundel, A.K., (2006). Two-Dimensional Depth-Averaged Circulation Model CMS-M2D: Version 3.0, Report 2, Sediment Transport and Morphology Change. ERDC/CHL TR-06-9 Vicksburg, MS: U.S. Army Engineer Research and Development Center. Lin, L., H. Mase, F. Yamada, and Z. Demirbilek. (2006). Wave-action balance equation diffraction (WABED) model: Tests of wave diffraction and reflection at inlets. Coastal and Hydraulics Engineering Technical Note ERDC/CHL CHETN-III-73. Vicksburg, MS: U.S. Army Engineer Research and Development Center. Faug\ue8res, J.C., Stow, D.A.V., Imbert, P., Viana, A.R. (1999). Seismic feature diagnostic of contourite drifts. Marine Geology 162, pp. 1-38

    In-Line-Test of Variability and Bit-Error-Rate of HfOx-Based Resistive Memory

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    Spatial and temporal variability of HfOx-based resistive random access memory (RRAM) are investigated for manufacturing and product designs. Manufacturing variability is characterized at different levels including lots, wafers, and chips. Bit-error-rate (BER) is proposed as a holistic parameter for the write cycle resistance statistics. Using the electrical in-line-test cycle data, a method is developed to derive BERs as functions of the design margin, to provide guidance for technology evaluation and product design. The proposed BER calculation can also be used in the off-line bench test and build-in-self-test (BIST) for adaptive error correction and for the other types of random access memories.Comment: 4 pages. Memory Workshop (IMW), 2015 IEEE Internationa

    Coastal altimetry products in the strait of Gibraltar

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    This paper analyzes the availability and accuracy of coastal altimetry sea level products in the Strait of Gibraltar. All possible repeats of two sections of the Envisat and AltiKa ground-tracks were used in the eastern and western portions of the strait. For Envisat, along-track sea level anomalies (SLAs) at 18-Hz posting rate were computed using ranges from two sources, namely, the official SGDRs and the outputs of a coastal waveform retracker, the ALES retracker; in addition, SLAs at 1 Hz were obtained from CTOH, France. For AltiKa, along-track SLA at 40 Hz was also computed both from SGDR and ALES ranges. The quality of these altimeter products was validated using two tide gauges located on the southern coast of Spain. We observed an improvement of about 20% in the accuracy of the Envisat SLAs from ALES compared to the standard (SGDR) and the reprocessed CTOH data sets. AltiKa shows higher accuracy, with no significant differences between SGDR and ALES
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