Astaxanthin is a natural C40 carotenoid with numerous reported biological functions, most of them associated with its antioxidant and anti-inflammatory activity, standing out from other antioxidants ...as it has shown the highest oxygen radical absorbance capacity (ORAC), 100–500 times higher than ⍺-tocopherol and a 10 times higher free radical inhibitory activity than related antioxidants (α-tocopherol, α-carotene, β -carotene, lutein and lycopene). In vitro and in vivo studies have associated astaxanthin's unique molecular features with several health benefits, including neuroprotective, cardioprotective and antitumoral properties, suggesting its therapeutic potential for the prevention or co-treatment of dementia, Alzheimer, Parkinson, cardiovascular diseases and cancer. Benefits on skin and eye health promotion have also been reported, highlighting its potential for the prevention of skin photo-aging and the treatment of eye diseases like glaucoma, cataracts and uveitis. In this review, we summarize and discuss the currently available evidence on astaxanthin benefits, with a particular focus on human clinical trials, including a brief description of the potential mechanisms of action responsible for its biological activities.
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Volcano-tectonic control of Cumbre Vieja González, Pablo J
Science (American Association for the Advancement of Science),
03/2022, Letnik:
375, Številka:
6587
Journal Article
Recenzirano
Odprti dostop
Unexpected features from the 2021 eruption might help forecast giant flank collapses.
Observations that unequivocally link seismicity and wastewater injection are scarce. Here we show that wastewater injection in eastern Texas causes uplift, detectable in radar interferometric data up ...to >8 kilometers from the wells. Using measurements of uplift, reported injection data, and a poroelastic model, we computed the crustal strain and pore pressure. We infer that an increase of >1 megapascal in pore pressure in rocks with low compressibility triggers earthquakes, including the 4.8-moment magnitude event that occurred on 17 May 2012, the largest earthquake recorded in eastern Texas. Seismic activity increased even while injection rates declined, owing to diffusion of pore pressure from earlier periods with higher injection rates. Induced seismicity potential is suppressed where tight confining formations prevent pore pressure from propagating into crystalline basement rocks.
•This study identifies the social value of heritage in relation to sustainable tourism.•It showcases the social dimension of the World Heritage Site of Altamira, Spain.•Findings show the multiple ...factors determining the social value of heritage.•The research paves the way for improving normative approaches toward sustainable tourism.•It offers practical solutions to the challenges faced by the Altamira WHS.
This study aims to identify the factors that constitute the social value of heritage in relation to sustainable tourism. To do so, this paper provides a theoretical contribution by unifying the fields of heritage management and sustainable tourism through a mixed-method approach. It showcases the social dimension of the World Heritage Site of Altamira, Spain, combining qualitative and quantitative techniques. Research findings provide information about the multiple factors determining the social value of heritage, namely: existential, aesthetic, economic, and legacy values and the risks associated with underestimating the contemporary social value. Ultimately, this research paves the way for improving normative approaches toward sustainable tourism and, offers practical solutions to the challenges faced by the Altamira and other World Heritage Sites.
Resolving changes in topography through time using accurate high‐resolution digital elevation models (DEMs) is key to understanding active volcanic processes. For the first time in a volcanic ...environment, we utilize very high‐resolution tri‐stereo optical imagery acquired by the Pleiades‐1 satellite constellation and generate a 1 m resolution DEM of Fogo Volcano, Cape Verde—the most active volcano in the Eastern Atlantic region. Point cloud density is increased by a factor of 6.5 compared to conventional stereo imagery, and the number of 1 m2 pixels with no height measurements is reduced by 43%. We use the DEM to quantify topographic changes associated with the 2014–2015 eruption at Fogo. Height differences between the posteruptive Pleiades‐1 DEM and the preeruptive topography from TanDEM‐X give a lava flow volume of 45.83 ± 0.02 × 106 m3, emplaced over an area of 4.8 km2 at a mean rate of 6.8 m3 s−1.
Key Points
Tri‐stereo photogrammetry at Fogo increases point cloud density by a factor of 6.5 and reduces area with no height measurements by 43%
Estimated accuracy of heights in generated tri‐stereo Pleiades‐1 DEM is <0.51 m
Lava flow volume and mean output rate of 2014–2015 Fogo eruption are 45.83 ± 0.02 × 106 m3 and 6.8 m3 s−1
ABSTRACT
The diffuse extragalactic background light (EBL) is formed by ultraviolet (UV), optical, and infrared (IR) photons mainly produced by star formation processes over the history of the ...Universe and contains essential information about galaxy evolution and cosmology. Here, we present a new determination of the evolving EBL spectral energy distribution using a novel approach purely based on galaxy data aiming to reduce current uncertainties on the higher redshifts and IR intensities. Our calculations use multiwavelength observations from the UV to the far-IR of a sample of approximately 150 000 galaxies detected up to z ∼ 6 in the five fields of the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey from the Hubble Space Telescope. This is one of the most comprehensive and deepest multiwavelength galaxy data sets ever obtained. These unprecedented resources allow us to derive the overall EBL evolution up to z ∼ 6 and its uncertainties. Our results agree with cosmic observables estimated from galaxy surveys and γ-ray attenuation such as monochromatic luminosity densities, including those in the far-IR, and star formation rate densities, also at the highest redshifts. Optical depths from our EBL approximation, which will be robust at high redshifts and for γ-rays up to tens of TeV, will be reported in a companion paper.
Using a sample of image28,000 sources selected at 3.6-4.5 mum with Spitzer observations of the Hubble Deep Field North, the Chandra Deep Field South, and the Lockman Hole (surveyed area image664 ...arcmin super(2)), we study the evolution of the stellar mass content of the universe at image. We calculate stellar masses and photometric redshifts, based on image2000 templates built with stellar population and dust emission models fitting the ultraviolet to mid-infrared spectral energy distributions of galaxies with spectroscopic redshifts. We estimate stellar mass functions for different redshift intervals. We find that 50% of the local stellar mass density was assembled at image (average star formation rate SFR 0.048 image yr super(- 1) Mpc super(-3)), and at least another 40% at image (average SFR 0.074 image yr super(-1) Mpc super(-3)). Our results confirm and quantify the 'downsizing' scenario of galaxy formation. The most massive galaxies assembled the bulk of their stellar content rapidly (in 1-2 Gyr) beyond image in very intense star formation events (producing high specific SFRs). Galaxies with image assembled half of their stellar mass before image, and more than 90% of their mass was already in place at image. Galaxies with image evolved more slowly (presenting smaller specific SFRs), assembling half of their stellar mass below image. About 40% of the local stellar mass density of image galaxies was assembled below image, most probably through accretion of small satellites producing little star formation. The cosmic stellar mass density at image is dominated by optically faint red galaxies (distant red galaxies or BzK sources), which account for image30% of the global population of galaxies, but contribute at least 60% of the cosmic stellar mass density. Bluer galaxies (e.g., Lyman break galaxies) are more numerous but less massive, contributing less than 50% of the global stellar mass density at high redshift.
The biaxial van der Waals semiconductor α‐phase molybdenum trioxide (α‐MoO3) has recently received significant attention due to its ability to support highly anisotropic phonon polaritons ...(PhPs)—infrared (IR) light coupled to lattice vibrations—offering an unprecedented platform for controlling the flow of energy at the nanoscale. However, to fully exploit the extraordinary IR response of this material, an accurate dielectric function is required. Here, the accurate IR dielectric function of α‐MoO3 is reported by modeling far‐field polarized IR reflectance spectra acquired on a single thick flake of this material. Unique to this work, the far‐field model is refined by contrasting the experimental dispersion and damping of PhPs, revealed by polariton interferometry using scattering‐type scanning near‐field optical microscopy (s‐SNOM) on thin flakes of α‐MoO3, with analytical and transfer‐matrix calculations, as well as full‐wave simulations. Through these correlative efforts, exceptional quantitative agreement is attained to both far‐ and near‐field properties for multiple flakes, thus providing strong verification of the accuracy of this model, while offering a novel approach to extracting dielectric functions of nanomaterials. In addition, by employing density functional theory (DFT), insights into the various vibrational states dictating the dielectric function model and the intriguing optical properties of α‐MoO3 are provided.
The IR permittivity of α‐MoO3 is extracted by correlative far‐ and near‐field measurements using FTIR reflectance spectroscopy and s‐SNOM polariton interferometry, thus providing a novel approach to extracting dielectric functions of nanomaterials. Moreover, through density functional theory, insights into the vibrational states dictating such permittivity are revealed.
The human respiratory syncytial virus (hRSV) is one of the most important causes of upper and lower respiratory tract infections in children and the main cause of bronchiolitis worldwide. Disease ...manifestations caused by hRSV may vary from mild to severe, occasionally requiring admission and hospitalization in intensive care units. Despite the high morbidity rates associated to bronchiolitis, treatment options against hRSV are limited and there are no current vaccination strategies to prevent infection. Importantly, the early identification of high-risk patients can help improve disease management and prevent complications associated with hRSV infection. Recently, the characterization of pro- and anti-inflammatory cytokine patterns produced during hRSV-related inflammatory processes has allowed the identification of potential prognosis biomarkers. A suitable biomarker should allow predicting the severity of the infection in a simple and opportune manner and should ideally be obtained from non-invasive samples. Among the cytokines associated with hRSV disease severity, IL-8, interferon-alpha (IFN-alpha), and IL-6, as well as the Th2-type cytokines thymic stromal lymphopoietin (TSLP), IL-3, and IL-33 have been highlighted as molecules with prognostic value in hRSV infections. In this review, we discuss current studies that describe molecules produced by patients during hRSV infection and their potential as biomarkers to anticipate the severity of the disease caused by this virus.
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