46 research outputs found

    Redox modulation by plant polyphenols targeting vitagenes for chemoprevention and therapy: Relevance to novel anti-cancer interventions and mini-brain organoid technology

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    The scientific community, recently, has focused notable attention on the chemopreventive and therapeutic effects of dietary polyphenols for human health. Emerging evidence demonstrates that polyphenols, flavonoids and vitamins counteract and neutralize genetic and environmental stressors, particularly oxidative stress and inflammatory process closely connected to cancer initiation, promotion and progression. Interestingly, polyphenols can exert antioxidant or pro-oxidant cytotoxic effects depending on their endogenous concentration. Notably, polyphenols at high dose act as pro-oxidants in a wide type of cancer cells by inhibiting Nrf2 pathway and the expression of antioxidant vitagenes, such as NAD(P)H-quinone oxidoreductase (NQO1), glutathione transferase (GT), GPx, heme oxygenase-1 (HO-1), sirtuin-1 (Sirt1) and thioredoxin (Trx) system which play an essential role in the metabolism of reactive oxygen species (ROS), detoxification of xenobiotics and inhibition of cancer progression, by inducing apoptosis and cell cycle arrest according to the hormesis approach. Importantly, mutagenesis of Nrf2 pathway can exacerbate its "dark side" role, representing a crucial event in the initiation stage of carcinogenesis. Herein, we review the hormetic effects of polyphenols and nanoincapsulated-polyphenols in chemoprevention and treatment of brain tumors via activation or inhibition of Nrf2/vitagenes to suppress carcinogenesis in the early stages, and thus inhibit its progression. Lastly, we discuss innovative preclinical approaches through mini-brain tumor organoids to study human carcinogenesis, from basic cancer research to clinical practice, as promising tools to recapitulate the arrangement of structural neuronal tissues and biological functions of the human brain, as well as test drug toxicity and drive personalized and precision medicine in brain cancer

    A major change in rate of climate niche envelope evolution during hominid history

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    Homo sapiens is the only species alive able to take advantage of its cognitive abilities to inhabit almost all environments on Earth. Humans are able to culturally construct, rather than biologically inherit, their occupied climatic niche to a degree unparalleled within the animal kingdom. Precisely when hominins acquired such an ability remains unknown, and scholars disagree on the extent to which our ancestors shared this same ability. Here, we settle this issue using fine-grained palaeoclimatic data, extensive archaeological data and phylogenetic comparative methods. Our results indicate that whereas early hominins were forced to live under physiologically suitable climatic conditions, with the emergence of H. heidelbergensis, the Homo climatic niche expanded beyond its natural limits, despite progressive harshening in global climates. This indicates that technological innovations providing effective exploitation of cold and seasonal habitats predated the emergence of Homo sapiens

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≀0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Model-based QoS-enabled self-healing Web Services

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    International audienceFailures during web service execution may depend on a wide variety of causes, such as network faults, server crashes, or application-related errors, such as unavailability of a requested web service, errors in the orchestration of choreography of applications, missing data or parameters in an execution flow, or low Quality of Service (QoS). In this paper, we propose a healing architecture able to handle web service faults in a self- healing way, discussing infrastructural faults and web service and Web application faults. The self-healing architecture manages repair actions, such as substitution of a faulty service or duplication of overloaded services. Implemented prototypes involving QoS in coordinated web services are illustrated and discussed

    Human face‐off: a new method for mapping evolutionary rates on three‐dimensional digital models

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    Modern phylogenetic comparative methods allow us to estimate evolutionary rates of phenotypic change, how these rates differ across clades, and to assess whether the rates remained constant over time. Unfortunately, currently available phylogenetic comparative tools express the rate in terms of a scalar dimension, and do not allow us to determine rate variations among different parts of a single, complex phenotype, or chart realized rate variation directly onto the phenotype. We present a new method which allows the mapping of evolutionary rate variation directly onto three-dimensional phenotypes, informing on the direction and magnitude of trait change automatically. Implemented using the function rate.map embedded in the R package RRphylo, this method is based on phylogenetic ridge regression rate estimates. Since the latter represent ridge regression slopes, they possess sign and magnitude. In RRphylo, different rates are calculated for different districts of the phenotype, which can then be visualized directly onto the phenotype itself. We present the application of rate.map to the evolution of facial skeleton in Hominoidea, the primate clade inclusive of Homo and the greater apes (including living and fossil taxa). We found that the highly derived, unique shape of the face in modern humans evolved through rapid phenotypic changes affecting the nasal bones, the brow ridge and the maxillary region. The canine fossa, a facial feature unique to Homo sapiens, did not belong to a region of rapid phenotypic change, and could be seen as the by-product of midface evolution as suggested by previous studies
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