3,938 research outputs found

    Association between Dietary Intake and Faecal Microbiota in Children with Cystic Fibrosis

    Get PDF
    [EN] A "high-fat, high-energy diet" is commonly recommended for children with cystic fibrosis (CF), leading to negative consequences on dietary patterns that could contribute to altered colonic microbiota. The aim of this study was to assess dietary intake and to identify possible associations with the composition of faecal microbiota in a cohort of children with CF. A cross-sectional observational study was conducted, including a 3-day food record simultaneously with the collection of faecal samples. The results showed a high fat intake (43.9% of total energy intake) and a mean dietary fibre intake of 10.6 g/day. The faecal microbiota was characterised at the phylum level as 54.5% Firmicutes and revealed an altered proportion between Proteobacteria (32%) and Bacteroidota (2.2%). Significant associations were found, including a negative association between protein, meat, and fish intake and Bifidobacterium, a positive association between lipids and Escherichia/Shigella and Streptococcus, a negative association between carbohydrates and Veillonella and Klebsiella, and a positive association between total dietary fibre and Bacteroides and Roseburia. The results reveal that a "high-fat, high-energy" diet does not satisfy dietary fibre intake from healthy food sources in children with CF. Further interventional studies are encouraged to explore the potential of shifting to a high-fibre or standard healthy diet to improve colonic microbiota.The authors would like to thank the Universitat Politècnica de València for the pre-doctoral contract from Vicerrectorado de Investigación given to Jazmín Viteri Echeverría (PAID-01-22). This project was funded with the First Project Grant (PAID-06-22) and Postdoctoral Research Fostering Grant (PAIDPD-22) from Vicerrectorado de Investigación (Universitat Politècnica de València) awarded to Andrea Asensio-Grau.Viteri-Echeverría, JD.; Calvo-Lerma, J.; Ferriz-Jordán, M.; Garriga, M.; García Hernández, J.; Heredia Gutiérrez, AB.; Ribes-Koninckx, C.... (2023). Association between Dietary Intake and Faecal Microbiota in Children with Cystic Fibrosis. Nutrients. 15(24). https://doi.org/10.3390/nu15245013152

    The origin of RXJ1856.5-3754 and RXJ0720.4-3125 -- updated using new parallax measurements

    Full text link
    RXJ1856 and RXJ0720 are the only young isolated radio-quiet neutron stars (NSs) for which trigonometric parallaxes were measured. Due to detection of their thermal emission in X-rays they are important to study NS cooling and to probe theoretical cooling models. Hence, a precise determination of their age is essential. Recently, new parallax measurements of RXJ1856 and RXJ0720 were obtained. Considering that NSs may originate from binary systems that got disrupted due to an asymmetric supernova, we attempt to identify runaway stars which may have been former companions to the NS progenitors. Such an identification would strongly support a particular birth scenario with time and place. We trace back each NS, runaway star and the centres of possible birth associations to find close encounters. The kinematic age is then given by the time since the encounter. We use Monte Carlo simulations to account for observational uncertainties. Using the most recent parallax measurement of 8.16+/-0.80 mas for RXJ1856, we find that it originated in the U Sco association 0.46+/-0.05 Myr ago. This is slightly larger than the value we reported earlier (0.3 Myr). Our result is strongly supported by its current radial velocity that we predict to be 6+19-20 km/s. This implies an inclination angle of 88+/-6 deg consistent with the bow shock. No suitable runaway star was found to be a potential former companion of RXJ1856. Making use of a recent parallax measurement for RXJ0720 of 3.6+/-1.6 mas, we find that this NS was possibly born in Tr 10 0.85+/-0.15 Myr ago. This is somewhat larger than the one obtained using the old parallax value (0.5 Myr). We suggest the B0 runaway supergiant HIP 43158 as a candidate for a former companion. Then, the current distance of RXJ0720 to the Sun should be 286+27-23 pc, in agreement with recent measurements. We then expect the radial velocity of RXJ0720 to be -76+34-17 km/s.Comment: accepted for publication in MNRAS additional supporting material can be found at http://www.astro.uni-jena.de/~nina/supporting_info.pdf the abstract has been adjusted to fit the length requirement (RXJ1856 = RXJ1856.5-3754, RXJ0720 = RXJ0720.4-3125, U Sco = Upper Scorpius, Tr 10 = Trumpler 10

    Electronic structure theory of the hidden order material URu2_2Si2_2

    Get PDF
    We report a comprehensive electronic structure investigation of the paramagnetic (PM), the large moment antiferromagnetic (LMAF), and the hidden order (HO) phases of URu2_2Si2_2. We have performed relativistic full-potential calculations on the basis of the density functional theory (DFT), employing different exchange-correlation functionals to treat electron correlations within the open 5f5f-shell of uranium. Specifically, we investigate---through a comparison between calculated and low-temperature experimental properties---whether the 5f5f electrons are localized or delocalized in URu2_2Si2_2. We also performed dynamical mean field theory calculations (LDA+DMFT) to investigate the temperature evolution of the quasi-particle states at 100~K and above, unveiling a progressive opening of a quasi-particle gap at the chemical potential when temperature is reduced. A detailed comparison of calculated properties with known experimental data demonstrates that the LSDA and GGA approaches, in which the uranium 5f5f electrons are treated as itinerant, provide an excellent explanation of the available low-temperature experimental data of the PM and LMAF phases. We show furthermore that due to a materials-specific Fermi surface instability a large, but partial, Fermi surface gapping of up to 750 K occurs upon antiferromagnetic symmetry breaking. The occurrence of the HO phase is explained through dynamical symmetry breaking induced by a mode of long-lived antiferromagnetic spin-fluctuations. This dynamical symmetry breaking model explains why the Fermi surface gapping in the HO phase is similar but smaller than that in the LMAF phase and it also explains why the HO and LMAF phases have the same Fermi surfaces yet different order parameters. Suitable derived order parameters for the HO are proposed to be the Fermi surface gap or the dynamic spin-spin correlation function.Comment: 23 pages, 20 figure

    Interatomic potentials for atomistic simulations of the Ti-Al system

    Full text link
    Semi-empirical interatomic potentials have been developed for Al, alpha-Ti, and gamma-TiAl within the embedded atomic method (EAM) by fitting to a large database of experimental as well as ab-initio data. The ab-initio calculations were performed by the linear augmented plane wave (LAPW) method within the density functional theory to obtain the equations of state for a number of crystal structures of the Ti-Al system. Some of the calculated LAPW energies were used for fitting the potentials while others for examining their quality. The potentials correctly predict the equilibrium crystal structures of the phases and accurately reproduce their basic lattice properties. The potentials are applied to calculate the energies of point defects, surfaces, planar faults in the equilibrium structures. Unlike earlier EAM potentials for the Ti-Al system, the proposed potentials provide reasonable description of the lattice thermal expansion, demonstrating their usefulness in the molecular dynamics or Monte Carlo studies at high temperatures. The energy along the tetragonal deformation path (Bain transformation) in gamma-TiAl calculated with the EAM potential is in a fairly good agreement with LAPW calculations. Equilibrium point defect concentrations in gamma-TiAl are studied using the EAM potential. It is found that antisite defects strongly dominate over vacancies at all compositions around stoichiometry, indicating that gamm-TiAl is an antisite disorder compound in agreement with experimental data.Comment: 46 pages, 6 figures (Physical Review B, in press

    A theory of intense-field dynamic alignment and high harmonic generation from coherently rotating molecules and interpretation of intense-field ultrafast pump-probe experiments

    Full text link
    A theory of ultra-fast pump-probe experiments proposed by us earlier [F.H.M. Faisal et al., Phys. Rev. Lett. 98, 143001 (2007) and F.H.M. Faisal and A. Abdurrouf, Phys. Rev. Lett. 100, 123005 (2008)] is developed here fully and applied to investigate the phenomena of dynamic alignment and high harmonic generation (HHG) from coherently rotating linear molecules. The theory provides essentially analytical results for the signals that allow us to investigate the simultaneous dependence of the HHG signals on the two externally available control parameters, namely, the relative angle between the polarizations, and the delay-time between the two pulses. It is applied to investigate the characteristics of high harmonic emission from nitrogen and oxygen molecules that have been observed experimentally in a number of laboratories. The results obtained both in the time-domain and in the frequency-domain are compared with the observed characteristics as well as directly with the data and are found to agree remarkably well. In addition we have predicted the existence of a "magic" polarization angle at which all modulations of the harmonic emission from nitrogen molecule changes to a steady emission at the harmonic frequency. Among other things we have also shown a correlation between the existence of the "magic" or critical polarization angles and the symmetry of the active molecular orbitals, that is deemed to be useful in connection with the "inverse problem" of molecular imaging from the HHG data.Comment: 31 pages, 22 figures, and 140 equation

    Ising superconductivity and magnetism in NbSe2_2

    Full text link
    Recent studies on superconductivity in NbSe2_2 have demonstrated a large anisotropy in the superconducting critical field when the material is reduced to a single monolayer. Motivated by this recent discovery, we use density functional theory (DFT) calculations to quantitatively address the superconducting properties of bulk and monolayer NbSe2_2. We demonstrate that NbSe2_2 is close to a ferromagnetic instability, and analyze our results in the context of experimental measurements of the spin susceptibility in NbSe2_2. We show how this magnetic instability, which is pronounced in a single monolayer, can enable sizeable singlet-triplet mixing of the superconducting order parameter, contrary to contemporary considerations of the pairing symmetry in monolayer NbSe2_2, and discuss approaches as to how this degree of mixing can be addressed quantitatively within our DFT framework. Our calculations also enable a quantitative description of the large anisotropy of the superconducting critical field, using DFT calculations of monolayer NbSe2_2 in the normal stateComment: 13 pages, 6 figure

    Spartan Daily, May 29, 1952

    Get PDF
    Volume 40, Issue 154https://scholarworks.sjsu.edu/spartandaily/11742/thumbnail.jp

    Individuals and Multilevel Management: A Study of the Perceived Adaptive Capacity of the Goose Management System among Farmers in Sweden

    Get PDF
    Agricultural damage by geese is a growing problem in Europe and farmers play a key role in the emerging multilevel adaptive management system. This study explored how characteristics associated with the farmer and the farm, along with experience of damage, cognitive appraisals, emotions, and management beliefs were associated with the perceived adaptive capacity of the goose management system among farmers in the south of Sweden (n = 1,067). Survey results revealed that owning a larger farm, a farm closer to water or formally protected areas, along with cultivating cereal and root crops, were associated with geese evoking stronger negative emotions. Further, more previous experience of damage was related to stronger negative emotions and lower levels of perceived adaptive capacity. However, even more important determinants of perceived adaptive capacity were cognitive appraisals, emotions, and management beliefs. Bridging the ties between individual farmers and the system is important for improved multilevel management
    • …
    corecore