150 research outputs found

    Genus Paracoccidioides: Species Recognition and Biogeographic Aspects

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    Background: Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis (species S1, PS2, PS3), and Paracoccidioides lutzii. This work aimed to differentiate species within the genus Paracoccidioides, without applying multilocus sequencing, as well as to obtain knowledge of the possible speciation processes. Methodology/Principal Findings: Single nucleotide polymorphism analysis on GP43, ARF and PRP8 intein genes successfully distinguished isolates into four different species. Morphological evaluation indicated that elongated conidia were observed exclusively in P. lutzii isolates, while all other species (S1, PS2 and PS3) were indistinguishable. To evaluate the biogeographic events that led to the current geographic distribution of Paracoccidioides species and their sister species, Nested Clade and Likelihood Analysis of Geographic Range Evolution (LAGRANGE) analyses were applied. The radiation of Paracoccidioides started in northwest South America, around 11–32 million years ago, as calculated on the basis of ARF substitution rate, in the BEAST program. Vicariance was responsible for the divergence among S1, PS2 and P. lutzii and a recent dispersal generated the PS3 species, restricted to Colombia. Taking into account the ancestral areas revealed by the LAGRANGE analysis and the major geographic distribution of L. loboi in the Amazon basin, a region strongly affected by the Andes uplift and marine incursions in the Cenozoic era, we also speculate about the effect of these geological events on the vicariance between Paracoccidioides and L. loboi. Conclusions/Significance: The use of at least 3 SNPs, but not morphological criteria, as markers allows us to distinguish among the four cryptic species of the genus Paracoccidioides. The work also presents a biogeographic study speculating on how these species might have diverged in South America, thus contributing to elucidating evolutionary aspects of the genus Paracoccidioides

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    Observation of B(s)0→J/ψpp¯ decays and precision measurements of the B(s)0 masses

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    The first observation of the decays B 0 ( s ) → J / ψ p ¯ p is reported, using proton-proton collision data corresponding to an integrated luminosity of 5.2     fb − 1 , collected with the LHCb detector. These decays are suppressed due to limited available phase space, as well as due to Okubo-Zweig-Iizuka or Cabibbo suppression. The measured branching fractions are B ( B 0 → J / ψ p ¯ p ) = [ 4.51 ± 0.40 ( stat ) ± 0.44 ( syst ) ] × 10 − 7 , B ( B 0 s → J / ψ p ¯ p ) = [ 3.58 ± 0.19 ( stat ) ± 0.39 ( syst ) ] × 10 − 6 . For the B 0 s meson, the result is much higher than the expected value of O ( 10 − 9 ) . The small available phase space in these decays also allows for the most precise single measurement of both the B 0 mass as 5279.74 ± 0.30 ( stat ) ± 0.10 ( syst )     MeV and the B 0 s mass as 5366.85 ± 0.19 ( stat ) ± 0.13 ( syst )     MeV

    Evidence for an nc(1S)ff- resonance in B0 yc(1S)K+ decays

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    A Dalitz plot analysis of B0→ηc(1S)K+π- decays is performed using data samples of pp collisions collected with the LHCb detector at centre-of-mass energies of s=7,8 and 13TeV , corresponding to a total integrated luminosity of 4.7fb-1 . A satisfactory description of the data is obtained when including a contribution representing an exotic ηc(1S)π- resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 4096±20-22+18MeV and 152±58-35+60MeV , respectively. The spin-parity assignments JP=0+ and JP=1- are both consistent with the data. In addition, the first measurement of the B0→ηc(1S)K+π- branching fraction is performed and gives B(B0→ηc(1S)K+π-)=(5.73±0.24±0.13±0.66)×10-4, where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions

    Observation and branching fraction measurement of the decay Ξb- → Λ0 bπ -

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    Precision measurement of CP\it{CP} violation in the penguin-mediated decay Bs0ϕϕB_s^{0}\rightarrow\phi\phi

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    A flavor-tagged time-dependent angular analysis of the decay Bs0ϕϕB_s^{0}\rightarrow\phi\phi is performed using pppp collision data collected by the LHCb experiment at % at s=13\sqrt{s}=13 TeV, the center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb^{-1}. The CP\it{CP}-violating phase and direct CP\it{CP}-violation parameter are measured to be ϕssˉs=0.042±0.075±0.009\phi_{s\bar{s}s} = -0.042 \pm 0.075 \pm 0.009 rad and λ=1.004±0.030±0.009|\lambda|=1.004\pm 0.030 \pm 0.009 , respectively, assuming the same values for all polarization states of the ϕϕ\phi\phi system. In these results, the first uncertainties are statistical and the second systematic. These parameters are also determined separately for each polarization state, showing no evidence for polarization dependence. The results are combined with previous LHCb measurements using pppp collisions at center-of-mass energies of 7 and 8 TeV, yielding ϕssˉs=0.074±0.069\phi_{s\bar{s}s} = -0.074 \pm 0.069 rad and lambda=1.009±0.030|lambda|=1.009 \pm 0.030. This is the most precise study of time-dependent CP\it{CP} violation in a penguin-dominated BB meson decay. The results are consistent with CP\it{CP} symmetry and with the Standard Model predictions.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-001.html (LHCb public pages

    Measurement of the Λb0Λ(1520)μ+μ\Lambda_{b}^{0}\to \Lambda(1520) \mu^{+}\mu^{-} differential branching fraction

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    The branching fraction of the rare decay Λb0Λ(1520)μ+μ\Lambda_{b}^{0}\to \Lambda(1520) \mu^{+}\mu^{-} is measured for the first time, in the squared dimuon mass intervals, q2q^2, excluding the J/ψJ/\psi and ψ(2S)\psi(2S) regions. The data sample analyzed was collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of $9\ \mathrm{fb}^{-1}.Theresultinthehighest. The result in the highest q^{2}interval, interval, q^{2} >15.0\ \mathrm{GeV}^2/c^4$, where theoretical predictions have the smallest model dependence, agrees with the predictions.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-050.html (LHCb public pages

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
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