MicroRNAs (miRNAs) are recognized as being central players in many biological processes and cellular pathways. Their roles in disease have been highlighted first by observation of their aberrant ...expression profiles in human tumors, and then by in vitro and in vivo functional studies in transformed cells and model organisms. One of the most commonly observed features of miRNAs in malignancies is a defect in their production. Although several causes may be associated with this phenomenon, such as upstream oncogenic/tumor-suppressor defects and alterations in the miRNA-processing machinery, epigenetic inactivation is the prime suspect. The number of miRNAs with putative growth-inhibitory functions undergoing promoter CpG island hypermethylation in human cancer is growing fast and more detailed biological studies are necessary. The recognition of miR-124a and miR-34b/c as bona fide tumor-suppressor miRNAs undergoing DNA methylation-associated silencing in a wide spectrum of human neoplasms is a good starting point to be followed by other candidate miRNAs. Most importantly, even at this early stage, the transcriptional repression of miRNAs by hypermethylation of their corresponding promoter loci seems to be a common feature of all human tumors. This will have translational consequences for the management of the disease.
We study the star formation quenching mechanism in cluster galaxies by fitting the spectral energy distribution (SED) of the Herschel Reference Survey, a complete volume-limited K-band-selected ...sample of nearby galaxies including objects in different density regions, from the core of the Virgo cluster to the general field. The SEDs of the target galaxies were fitted using the CIGALE SED modelling code. The truncated activity of cluster galaxies was parametrised using a specific star formation history with two free parameters, the quenching age QA and the quenching factor QF. These two parameters are crucial for the identification of the quenching mechanism, which acts on long timescales when starvation processes are at work, but is rapid and efficient when ram pressure occurs. To be sensitive to an abrupt and recent variation of the star formation activity, we combined twenty photometric bands in the UV to far-infrared in a new way with three age-sensitive Balmer line absorption indices extracted from available medium-resolution (R ~ 1000) integrated spectroscopy and with Hα narrow-band imaging data. The use of a truncated star formation history significantly increases the quality of the fit in HI-deficient galaxies of the sample, that is to say, in those objects whose atomic gas content has been removed during the interaction with the hostile cluster environment. The typical quenching age of the perturbed late-type galaxies is QA ≲ 300 Myr whenever the activity of star formation is reduced by 50% < QF ≤ 80% and QA ≲ 500 Myr for QF > 80%, while that of the quiescent early-type objects is QA ≃ 1−3 Gyr. The fraction of late-type galaxies with a star formation activity reduced by QF > 80% and with an HI-deficiency parameter HI−def > 0.4 drops by a factor of ~5 from the inner half virial radius of the Virgo cluster (R/Rvir < 0.5), where the hot diffuse X-ray emitting gas of the cluster is located, to the outer regions (R/Rvir > 4). The efficient quenching of the star formation activity observed in Virgo suggests that the dominant stripping process is ram pressure. We discuss the implication of this result in the cosmological context of galaxy evolution.
ABSTRACT
We present sofia 2, the fully automated 3D source finding pipeline for the WALLABY extragalactic H i survey with the Australian SKA Pathfinder (ASKAP). sofia 2 is a reimplementation of parts ...of the original sofia pipeline in the c programming language and makes use of OpenMP for multithreading of the most time-critical algorithms. In addition, we have developed a parallel framework called sofia-X that allows the processing of large data cubes to be split across multiple computing nodes. As a result of these efforts, sofia 2 is substantially faster and comes with a much reduced memory footprint compared to its predecessor, thus allowing the large WALLABY data volumes of hundreds of gigabytes of imaging data per epoch to be processed in real time. The source code has been made publicly available to the entire community under an open-source licence. Performance tests using mock galaxies injected into genuine ASKAP data suggest that in the absence of significant imaging artefacts sofia 2 is capable of achieving near-100 per cent completeness and reliability above an integrated signal-to-noise ratio (SNR) of about 5–6. We also demonstrate that sofia 2 generally recovers the location, integrated flux, and w20 line width of galaxies with high accuracy. Other parameters, including the peak flux density and w50 line width, are more strongly biased due to the influence of the noise on the measurement. In addition, very faint galaxies below an integrated SNR of about 10 may get broken up into multiple components, thus requiring a strategy to identify fragmented sources and ensure that they do not affect the integrity of any scientific analysis based on the sofia 2 output.
Environmental concerns gather considerable academic research and private investment, namely when addressing water and energy. Wastewater treatment and reuse have become a standard practice across the ...globe. In Europe, this topic has been addressed through the European Commission policy for the environment. Microbial Fuel Cells are a useful technology for wastewater treatment. They can be used for resource scavenging and energy production. Their power output still can't counterbalance, per se, the energy expenditure on wastewater treatment stations, but it can help provide autonomy for physical, chemical, and biochemical measurements in wastewater. The true energetic potential, however, has not been fully exploited, since significant energy losses are still associated with these systems, decreasing the efficiency of this technology. As works with microbial fuel cells grow in number and diversity, an adequate review of the strategies used to apply these devices as power sources is needed.
This work explores the most relevant research, to date, about maximum power extraction from Microbial Fuel Cells, addressing, in detail, the power conditioning devices and strategies for power improvement: from single cells with passive components to cell groups and active strategies, using maximum power point tracking techniques and power converters in different operating modes.
•Benthic Microbial Fuel Cells were the first to produce energy from wastewater.•Passive and active solutions can harvest energy from Microbial Fuel Cells.•Maximum power extraction may happen without energy-intensive approaches.•The Cell's biofilm has energy, available by adjusting charging/recovering times.
The use of Microbial Fuel Cells as power sources in rural or remote locations can solve issues related with power availability and wastewater cleaning. Furthermore, the application of such technology ...in wireless smart sensors applied to wastewater treatment plants can also help in water quality monitoring, increasing the process autonomy and reliability. A trustworthy power source needs to have a predictable and repeatable behavior, which cannot be achieved without adequate models and supporting hardware for energy regulation and storage. The work herein described proposes a steady-state model, represented by an electric circuit made of passive components. This model was first applied to a specific 28 mL air-cathode Microbial Fuel Cells working with artificial wastewater and using graphite brush anodes. Afterwards, the model was further validated by applying it to a larger reactor and to other bibliographic records. The goal of the study is to propose a method for finding a Microbial Fuel Cell model to be used with maximum power point tracking research, guaranteeing the best-case scenario for Microbial Fuel Cell operation as a power source. The reactors used in this study were analyzed by relating time and voltage development, both in colonization and in polarization studies. A mathematical relationship model was developed and proposed allowing to separate MFC's behavior, concerning energy production, in to meaningful components. From the experimental data the method was used to obtain a two-component circuit model that describes the power behavior of this specific Microbial Fuel Cell topology. The same method can be used to described other MFC.
•Power development on Microbial Fuel Cells is not linear with time, external load or reactor volume.•The internal resistance of a Microbial Fuel Cell can be approximated without using a potentiostat.•The polarization curve equation can be estimated and further used for power studies.•The proposed method allows quantifying each of the power losses.•The steady-state power development of Microbial Fuel Cells can be modeled by a Voltage Source and a Resistance.
This article develops a spatial analysis applied to examine the main driving forces of land-cover and land-use (LCLU) change in a Mediterranean region. Three different tools have been used in order ...to differentiate LCLU changes, driving forces and landscape dynamics. LCLU changes have been quantified with remote sensing techniques, driving forces have been analysed with multiple logistic regressions combining biophysical and human variables, whereas landscape dynamics have been quantified using different metrics. Results show the intensification of subsidised herbaceous crops on the coastal agricultural plain, the abandonment of olive trees and vineyards in the transitional area and forest restoration in the mountainous subregion.
Fusion oncogenes (FOs) are common in many cancer types and are powerful drivers of tumor development. Because their expression is exclusive to cancer cells and their elimination induces cell ...apoptosis in FO-driven cancers, FOs are attractive therapeutic targets. However, specifically targeting the resulting chimeric products is challenging. Based on CRISPR/Cas9 technology, here we devise a simple, efficient and non-patient-specific gene-editing strategy through targeting of two introns of the genes involved in the rearrangement, allowing for robust disruption of the FO specifically in cancer cells. As a proof-of-concept of its potential, we demonstrate the efficacy of intron-based targeting of transcription factors or tyrosine kinase FOs in reducing tumor burden/mortality in in vivo models. The FO targeting approach presented here might open new horizons for the selective elimination of cancer cells.
We present MeerKAT 1000 MHz and 1400 MHz observations of a bright radio galaxy in the southern hemisphere, ESO 137-006. The galaxy lies at the centre of the massive and merging Norma galaxy cluster. ...The MeerKAT continuum images (rms ∼0.02 mJy beam
−1
at ∼10″ resolution) reveal new features that have never been seen in a radio galaxy before: collimated synchrotron threads of yet unknown origin, which link the extended and bent radio lobes of ESO 137-006. The most prominent of these threads stretches in projection for about 80 kpc and is about 1 kpc in width. The radio spectrum of the threads is steep, with a spectral index of up to
α
≃ 2 between 1000 and 1400 MHz.
We present new observations of Fornax A taken at ∼1 GHz with the MeerKAT telescope and at ∼6 GHz with the Sardinia Radio Telescope (SRT). The sensitive (noise ∼16
μ
Jy beam
−1
), high-resolution ...(≲10″) MeerKAT images show that the lobes of Fornax A have a double-shell morphology, where dense filaments are embedded in a diffuse and extended cocoon. We study the spectral properties of these components by combining the MeerKAT and SRT observations with archival data between 84 MHz and 217 GHz. For the first time, we show that multiple episodes of nuclear activity must have formed the extended radio lobes. The modelling of the radio spectrum suggests that the last episode of injection of relativistic particles into the lobes started ∼24 Myr ago and stopped 12 Myr ago. More recently (∼3 Myr ago), a less powerful and short (≲1 Myr) phase of nuclear activity generated the central jets. Currently, the core may be in a new active phase. It appears that Fornax A is rapidly flickering. The dense environment around Fornax A has lead to a complex recent merger history for this galaxy, including mergers spanning a range of gas contents and mass ratios, as shown by the analysis of the galaxy’s stellar- and cold-gas phases. This complex recent history may be the cause of the rapid, recurrent nuclear activity of Fornax A.
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