980 research outputs found

    Free monadic Tarski and MMI3-algebras

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    MMI3-algebras are a generalization of the monadic Tarski algebras as defined by A. Monteiro and L. Iturrioz, and a particular case of the MMIn+1-algebras defined by A. Figallo. They can also be seen as monadic three-valued £ukasiewicz algebras without a first element. By using this point of view, and the free monadic extensions, we construct the free MMI3-algebras on a finite number of generators, and indicate the coordinates of the generators. As a byproduct, we also obtain a construction of the free monadic Tarski algebras.Fil: Entizne, Rosana V.. Universidad Nacional del Sur. Departamento de Matemática; ArgentinaFil: Monteiro, Luiz F.. Universidad Nacional del Sur. Departamento de Matemática; ArgentinaFil: Savini, Sonia M.. Universidad Nacional del Sur. Departamento de Matemática; ArgentinaFil: Viglizzo, Ignacio Dario. Universidad Nacional del Sur. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentin

    Comparative Analysis of Phenolic Composition of Six Commercially Available Chamomile (Matricaria chamomilla L.) Extracts: Potential Biological Implications

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    Several phytochemical-containing herbal extracts are increasingly marketed as health-promoting products. In particular, chamomile (Matricaria recutita L.) is well known for its anti-inflammatory, analgesic, and antitumor properties. Here, we evaluated differences in chemical composition among six commercially available products and their potential impact on biological activity in human immortalized colonocytes. Our investigation encompassed: (i) preparation of dry extracts and yield evaluation; (ii) qualitative and quantitative analysis of phenol content; (iii) modulation of redox state; and (iv) bioavailability of main bioactive compounds. We demonstrated that apparently identical products showed huge heterogeneity, in terms of yield extraction, chemical composition, and antioxidant effects. All samples contained high amounts of flavonoids and cinnamic acid derivatives, but differentially concentrated in the six extracts. Depending on polyphenol content, chamomile samples possessed variable antioxidant potential, in terms of decreased radical generation and increased reduced glutathione levels. The observed effects might be ascribed to flavones (apigenin, luteolin, and their glycones) highly represented in the six extracts. Nonetheless, chamomile extracts exerted cytotoxic effects at high concentrations, suggesting that a herbal medicine is not always safe. In conclusion, due to the complexity and variability of plant matrices, studies evaluating effectiveness of chamomile should always be accompanied by preliminary characterization of phytochemical composition

    Dietary Strategies for Management of Metabolic Syndrome: Role of Gut Microbiota Metabolites

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    Metabolic syndrome (MetS) is a complex pathophysiological state with incidence similar to that of a global epidemic and represents a risk factor for the onset of chronic non-communicable degenerative diseases (NCDDs), including cardiovascular disease (CVD), type 2 diabetes mellitus, chronic kidney disease, and some types of cancer. A plethora of literature data suggest the potential role of gut microbiota in interfering with the host metabolism, thus influencing several MetS risk factors. Perturbation of the gut microbiota's composition and activity, a condition known as dysbiosis, is involved in the etiopathogenesis of multiple chronic diseases. Recent studies have shown that some micro-organism-derived metabolites (including trimethylamine N-oxide (TMAO), lipopolysaccharide (LPS) of Gram-negative bacteria, indoxyl sulfate and p-cresol sulfate) induce subclinical inflammatory processes involved in MetS. Gut microbiota's taxonomic species or abundance are modified by many factors, including diet, lifestyle and medications. The main purpose of this review is to highlight the correlation between different dietary strategies and changes in gut microbiota metabolites. We mainly focus on the validity/inadequacy of specific dietary patterns to reduce inflammatory processes, including leaky gut and subsequent endotoxemia. We also describe the chance of probiotic supplementation to interact with the immune system and limit negative consequences associated with MetS

    Macular Microcysts in Mitochondrial Optic Neuropathies: Prevalence and Retinal Layer Thickness Measurements.

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    PurposeTo investigate the thickness of the retinal layers and to assess the prevalence of macular microcysts (MM) in the inner nuclear layer (INL) of patients with mitochondrial optic neuropathies (MON).MethodsAll patients with molecularly confirmed MON, i.e. Leber's Hereditary Optic Neuropathy (LHON) and Dominant Optic Atrophy (DOA), referred between 2010 and 2012 were enrolled. Eight patients with MM were compared with two control groups: MON patients without MM matched by age, peripapillary retinal nerve fiber layer (RNFL) thickness, and visual acuity, as well as age-matched controls. Retinal segmentation was performed using specific Optical coherence tomography (OCT) software (Carl Zeiss Meditec). Macular segmentation thickness values of the three groups were compared by one-way analysis of variance with Bonferroni post hoc corrections.ResultsMM were identified in 5/90 (5.6%) patients with LHON and 3/58 (5.2%) with DOA. The INL was thicker in patients with MON compared to controls regardless of the presence of MM [133.1±7μm vs 122.3±9μm in MM patients (p<0.01) and 128.5±8μm vs. 122.3±9μm in no-MM patients (p<0.05)], however the outer nuclear layer (ONL) was thicker in patients with MM (101.4±1mμ) compared to patients without MM [77.5±8mμ (p<0.001)] and controls [78.4±7mμ (p<0.001)]. ONL thickness did not significantly differ between patients without MM and controls.ConclusionThe prevalence of MM in MON is low (5-6%), but associated with ONL thickening. We speculate that in MON patients with MM, vitreo-retinal traction contributes to the thickening of ONL as well as to the production of cystic spaces

    Monte Carlo Transmission Line Modeling of Multilayer Optical Coatings for Performance Sensitivity of a Dichroic Filter for the ARIEL Space Telescope

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    Dichroic beamsplitters, or dichroics, are filters that rely on the optical interference that occurs within thin layers to ensure the transmission and reflection of selective wavelengths of an incident beam of light. These optical components consist of a substrate coated on one or both surfaces with multiple layers of thin films, the spectral design and construction of which determine the isolation of particular wavebands. Discrepancies between the measured and expected spectral performance of optical elements with such coatings can largely be attributed to depositions errors and uncertainties in the refractive indices of the materials. Our model uses two-dimensional transmission line modeling to evaluate the transmittance of light through multilayer coatings deposited on a substrate material for given materials, angle of incidence and polarisation. This model allows us to perform Monte Carlo simulations to obtain statistical information about the tolerance of the coating performance to systematic and random uncertainties from the manufacturing process, as well as from environmental changes in space. With the aid of accurate manufacturing recipes and uncertainty amplitudes from commercial manufacturers, this tool can predict variations in the optical performance that result from the propagation of each of these uncertainties for various hypothetical scenarios. One particular application of this study are the dichroics of the ARIEL space telescope. We compare the predicted optical performance with transmission measurements at cryogenic temperatures for one of the ARIEL dichroics, which show the specification compliance of this prototype after many thermal cycles

    Planck pre-launch status: HFI beam expectations from the optical optimisation of the focal plane

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    Planck is a European Space Agency (ESA) satellite, launched in May 2009, which will map the cosmic microwave background anisotropies in intensity and polarisation with unprecedented detail and sensitivity. It will also provide full-sky maps of astrophysical foregrounds. An accurate knowledge of the telescope beam patterns is an essential element for a correct analysis of the acquired astrophysical data. We present a detailed description of the optical design of the High Frequency Instrument (HFI) together with some of the optical performances measured during the calibration campaigns. We report on the evolution of the knowledge of the pre-launch HFI beam patterns when coupled to ideal telescope elements, and on their significance for the HFI data analysis procedure

    Investigation of a Staphylococcus aureus sequence type 72 food poisoning outbreak associated with food-handler contamination in Italy

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    On August 2019 a staphylococcal food poisoning outbreak occurred in an elderly home in Piedmont, Italy. The epidemiological investigation performed among the per- sons that consumed the meal identified chicken salad as the most likely source of the outbreak. Staphylococcus aureus was isolated from a total of seven samples, namely one vomit sample from a guest of the nursing home, two food samples (chicken salad with and without mayonnaise) and nasal swabs collected from a total of four persons working in the kitchen of the nursing home. The maximum likelihood tree obtained using single nucleotide polymorphisms analysis revealed that the isolates from the aforementioned samples clustered together. Multilocus sequence typing revealed that they belonged to Sequence Type 72. Fourier transform infrared spectroscopy (FTIR) was used in parallel to single nucleotide polymorphisms and whole genome sequencing for the determination of the degree of relatedness of the isolates. The results of the FTIR showed the same clustering obtained with single nucleotide poly- morphisms and whole genome sequencing and revealed the source of infection. This study underlines the importance of both laboratory evidence and epidemiological data for outbreak investigation and further confirms that FTIR is a suitable support for the short-term epidemiological investigation on source attribution in case of a S. aureus infection

    The use of a cubesat to validate technological bricks in space

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    In the framework of the FP7 program FISICA (Far Infrared Space Interferometer Critical Assessment), we are developing a cubesat platform which will be used for the validation in space of two technological bricks relevant for FIRI. The first brick is a high-precision accelerometer which could be used in a future space mission as fundamental element for the dynamic control loop of the interferometer. The second brick is a miniaturized version of an imaging multi-aperture telescope. Ultimately, such an instrument could be composed of numerous space-born mirror segments flying in precise formation on baselines of hundreds or thousands of meters, providing high-resolution glimpses of distant worlds. We are proposing to build a very first space-born demonstrator of such an instrument which will fit into the limited resources of one cubesat. In this paper, we will describe the detailed design of the cubesat hosting the two payloads

    First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster

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    Diffuse synchrotron radio emission from cosmic-ray electrons is observed at the center of a number of galaxy clusters. These sources can be classified either as giant radio halos, which occur in merging clusters, or as mini halos, which are found only in cool-core clusters. In this paper, we present the first discovery of a cool-core cluster with an associated mini halo that also shows ultra-steep-spectrum emission extending well beyond the core that resembles radio halo emission. The large-scale component is discovered thanks to LOFAR observations at 144 MHz. We also analyse GMRT observations at 610 MHz to characterise the spectrum of the radio emission. An X-ray analysis reveals that the cluster is slightly disturbed, and we suggest that the steep-spectrum radio emission outside the core could be produced by a minor merger that powers electron re-acceleration without disrupting the cool core. This discovery suggests that, under particular circumstances, both a mini and giant halo could co-exist in a single cluster, opening new perspectives for particle acceleration mechanisms in galaxy clusters
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