Deep learning regression for inverse quantum scattering

In this work we study the inverse quantum scattering via deep learning regression, which is implemented via a Multilayer Perceptron. A step-by-step method is provided in order to obtain the potential parameters. A circular boundary-wall potential was chosen to exemplify the method. Detailed discussion about the training is provided. A investigation with noisy data is presented and it is observed that the neural network is useful to predict the potential parameters

High speed sCMOS-based oblique plane microscopy applied to the study of calcium dynamics in cardiac myocytes

blique plane microscopy (OPM) is a form of light sheet microscopy that uses a single high numerical aperture microscope objective for both fluorescence excitation and collection. In this paper, measurements of the relative collection efficiency of OPM are presented. An OPM system incorporating two sCMOS cameras is then introduced that enables single isolated cardiac myocytes to be studied continuously for 22 seconds in two dimensions at 667 frames per second with 960 × 200 pixels and for 30 seconds with 960 × 200 × 20 voxels at 25 volumes per second. In both cases OPM is able to record in two spectral channels, enabling intracellular calcium to be studied via the probe Fluo-4 AM simultaneously with the sarcolemma and transverse tubule network via the membrane dye Cellmask Orange. The OPM system was then applied to determine the spatial origin of spontaneous calcium waves for the first time and to measure the cell transverse tubule structure at their point of origin. Further results are presented to demonstrate that the OPM system can also be used to study calcium spark parameters depending on their relationship to the transverse tubule structure

Stem cells and physical energies: can we really drive stem cell fate?

Adult stem cells are undifferentiated elements able to self-renew or differentiate to maintain tissue integrity. Within this context, stem cells are able to divide in a symmetric fashion, feature characterising all the somatic cells, or in an asymmetric way, which leads daughter cells to different fates. It is worth highlighting that cell polarity have a critical role in regulating stem cell asymmetric division and the proper control of cell division depends on different proteins involved in cell development, differentiation and maintenance of tissue homeostasis. Moreover, the interaction between cells and the extracellular matrix are crucial in influencing cell behavior, included in terms of mechanical properties as cytoskeleton plasticity and remodelling, and membrane tension. Finally, the activation of specific transcriptional program and epigenetic modifications contributes to cell fate determination, through modulation of cellular signalling cascades. It is well known that physical and mechanical stimuli are able to influence biological systems, and in this context, the effects of electromagnetic fields (EMFs) have already shown a considerable role, even though there is a lack of knowledge and much remains to be done around this topic. In this review, we summarize the historical background of EMFs applications and the main molecular mechanism involved in cellular remodelling, with particular attention to cytoskeleton elasticity and cell polarity, required for driving stem cell behavior

Unravelling cellular mechanisms of stem cell senescence: An aid from natural bioactive molecules

Cellular senescence plays a role in the onset of age-related pathologies and in the loss of tissue homeostasis. Natural compounds of food or plants exert an important antioxidant activity, counteracting the formation of harmful free radicals. In the presence of an intense stressing event, cells activate specific responses to counteract senescence or cell death. In the present paper, we aimed at evaluating the levels of expression of specific markers of senescence, in order to demonstrate that extracts from Myrtus Communis L. can prevent premature senescence in ADSCs exposed to oxidative stress. Cells were cultured in the presence of Myrtus extracts for 12–24 and 48 h and then incubated with H2O2 to induce senescence. We then evaluated the expression of senescence-related markers p16, p19, p21, p53, TERT, c-Myc, and the senescence-associated β-Galactoidase activity. Our results showed that pre-treatment with Myrtus extracts protects cells from premature senescence, by regulating the cell cycle, and inducing the expression of TERT and c-Myc. These findings suggest a potential application of these natural compounds in the prevention and treatment of various diseases, counteracting premature senescence and preserving tissue functions

Risk-Informed design process of the IRIS reactor

Westinghouse is currently conducting the pre-application licensing of the International Reactor Innovative and Secure (IRIS). The design philosophy of the IRIS has been based on the concept of Safety-by-DesignTM and within this framework the PSA is being used as an integral part of the design process. The basis for the PSA contribution to the design phase of the reactor is the close iteration between the PSA team and the design and safety analysis team. In this process the design team is not only involved in the initial phase of providing system information to the PSA team, allowing in this way the identification of the high risk scenarios, but it is also receiving feedback from the PSA team that suggests design modification aimed at reaching risk-related goals. During the first iteration of this process, the design modifications proposed by the PSA team allowed reducing the initial estimate of Core Damage Frequency (CDF) due to internal events from 2E-6/ry to 2E-8/ry. Since the IRIS design is still in a development phase, a number of assumptions have to be confirmed when the design is finalized. Among key assumptions are the success criteria for both the accident sequences analyzed and the systems involved in the mitigation strategies. The PSA team developed the initial accident sequence event trees according to the information from the preliminary analysis and feasibility studies. A recent coupling between the RELAP and GOTHIC codes made possible the actual simulation of all LOCA sequences identified in the first draft of the Event Trees. Working in close coordination, the PSA and the safety analysis teams developed a matrix case of sequences not only with the purpose of testing the assumed success criteria, but also with the perspective of identifying alternative sequences developed mainly by relaxing the extremely conservative assumptions previously made. The results of these simulations, bounded themselves with conservative assumptions on the Core Damage definition, suggested two new versions of the LOCA Event Tree with two possible configurations of the Automatic Depressurization System. The new CDF has been evaluated for both configurations and the design team has been provided with an additional and risk-related perspective that will help choosing the design alternative to be implemented

Removal of radioisotopes in solution and bactericidal/bacteriostatic sterilising power in activated carbon and metal silver filters

Activated carbon filters play an important role in water filtration and purification from contaminants of different origin. Their limit consists in bacterial proliferation, which may occur only during prolonged periods of non-use and in their ability to remove radioactive contaminants present in waste water from Industry or Nuclear Medicine departments. In this work we tested a commercially available activated carbon filter for water purification enriched with silver plated parts incubating in static condition at room temperature different micro organisms (Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus, Aspergillum niger), up to 78 days. The microbial growth was in general more inhibited in the presence of metal silver into the activated carbon in respect to filters with the activated carbon alone: >4 log inhibition of bacterial proliferation after 78 days of incubation the presence of silver vs. 2 log without silver. When the filters were incubated empty of carbon, the sterilizing power of silver was confirmed further. The activated carbon filters proved also their ability in removing fromwater the principal radioisotopes used for residues liquid medical and research purposes (131I, 99mTc, 201Tl, 67Ga). These results contribute useful data for the use of the silver-enriched carbon filters in water filtration both for daily use at home, and professional use in a Nuclear Medicine laboratory

Antisenescence Effect of REAC Biomodulation to Counteract the Evolution of Myelodysplastic Syndrome

About 30 percent of patients diagnosed with myelodysplastic syndromes (MDS) progress to acute myeloid leukemia (AML). The senescence of bone marrow‐derived mesenchymal stem cells (BMSCs) seems to be one of the determining factors in inducing this drift. Research is continuously looking for new methodologies and technologies that can use bioelectric signals to act on senescence and cell differentiation towards the phenotype of interest. The Radio Electric Asymmetric Conveyer (REAC) technology, aimed at reorganizing the endogenous bioelectric activity, has already shown to be able to determine direct cell reprogramming effects and counteract the senescence mechanisms in stem cells. Aim of the present study was to prove if the anti-senescence results previously obtained in different kind of stem cells with the REAC Tissue optimization – regenerative (TO-RGN) treatment, could also be observed in BMSCs, evaluating cell viability, telomerase activity, p19ARF, P21, P53, and hTERT gene expression. The results show that the REAC TORGN treatment may be a useful tool to counteract the BMSCs senescence which can be the basis of AML drift. Nevertheless, further clinical studies on humans are needed to confirm this hypothesis

World Press Photo 2012: the discursive construction of the Arab Spring

O presente artigo pretende analisar a forma como o fenómeno da Primavera Árabe foi retratado nas fotografias vencedoras do concurso World Press Photo em 2012. As fotografias jornalísticas, embora se apresentem como índices do real, condicionam frequentemente a percepção dos indivíduos e influenciam as suas práticas sociais. Também as fotografias vencedoras do World Press Photo, um dos concursos mais prestigiados de fotojornalismo, em 2012 não fogem ao construtivismo discursivo que molda a representação e a percepção dos acontecimentos. A partir da análise crítica do discurso, nomeadamente dos instrumentos teóricos da semiótica barthesiana e da semiótica social de Gunther Kress e Theo van Leeuwen, procurámos interpretar as 38 fotografias vencedoras do World Press Photo 2012, a fim de reflectirmos sobre o modo como contribuíram para a compreensão da Revolta Árabe e como despertaram o nosso interesse e a nossa imaginação para o desenrolar do conflito.ABSTRACT:This article aims to analyze how the Arab Spring phenomenon was represented in the award-winning photographs of the World Press Photo contest in 2012. Although news photographs are usually seen as indexes of the real, they often limit the perception of individuals and influence their social practices. Also the winning photographs in 2012 of the World Press Photo, one of the most prestigious photojournalism contests, do not escape the discursive constructivism that shapes the representation and perception of events. Drawing from critical discourse analysis, namely from the theoretical tools of barthesian semiotics and Gunther Kress’s and Theo van Leeuwen’s social semiotics, we sought to interpret the 38 award-winning photographs of the World Press Photo contest in 2012, in order to reflect on the way they have contributed to our understanding of the Arab Revolt and aroused our interest and imagination to the unfolding of the conflict.info:eu-repo/semantics/publishedVersio