821 research outputs found
Atmospheric fluctuations below 0.1 Hz during drift-scan solar diameter measurements
Measurements of the power spectrum of the seeing in the range 0.001-1 Hz have
been performed in order to understand the criticity of the transits' method for
solar diameter monitoring.Comment: 3 pages, 3 figures, proc. of the Fourth French-Chinese meeting on
Solar Physics Understanding Solar Activity: Advances and Challenges, 15 - 18
November, 2011 Nice, Franc
Child healthcare services offered by the Vatican City State in its national territory and in extra-territorial neighboring Italian areas
Pediatric healthcare activity related to the Vatican City State is carried out at secondary and tertiary levels in the two main pediatric territorial and extra-territorial medical centers, which are administered by the Vatican: the Bambino Gesu Pediatric Hospital and the Mother and Child pediatric Department of the Casa Sollievo della Sofferenza Medical Center. Both centers are recognized by the Italian State and internationally with the formal legal status of Scientific Institutes for Clinical Research. The relations established between the Holy See, in the person of the Secretary of State, the Board of Directors, the President of the Board, and the Board of Auditors regulate the management of the two medical centers. The child healthcare and research activity of the two Vatican State administered medical centers is described in this article
Risk factors for recurrence in patients with Clostridium difficile infection due to 027 and non-027 ribotypes
Objectives: Our objective was to evaluate factors associated with recurrence in patients with 027+ and 027– Clostridium difficile infection (CDI). Methods: Patients with CDI observed between January and December 2014 in six hospitals were consecutively included in the study. The 027 ribotype was deduced by the presence of tcdB, tcdB, cdt genes and the deletion Δ117 in tcdC (Xpert® C. difficile/Epi). Recurrence was defined as a positive laboratory test result for C. difficile more than 14 days but within 8 weeks after the initial diagnosis date with reappearance of symptoms. To identify factors associated with recurrence in 027+ and 027– CDI, a multivariate analysis was performed in each patient group. Subdistributional hazard ratios (sHRs) and 95% confidence intervals (95%CIs) were calculated. Results: Overall, 238 patients with 027+ CDI and 267 with 027– CDI were analysed. On multivariate analysis metronidazole monotherapy (sHR 2.380, 95%CI 1.549–3.60, p <0.001) and immunosuppressive treatment (sHR 3.116, 95%CI 1.906–5.090, p <0.001) were factors associated with recurrence in patients with 027+ CDI. In this patient group, metronidazole monotherapy was independently associated with recurrence in both mild/moderate (sHR 1.894, 95%CI 1.051–3.410, p 0.033) and severe CDI (sHR 2.476, 95%CI 1.281–4.790, p 0.007). Conversely, non-severe disease (sHR 3.704, 95%CI 1.437–9.524, p 0.007) and absence of chronic renal failure (sHR 16.129, 95%CI 2.155–125.000, p 0.007) were associated with recurrence in 027– CDI. Conclusions: Compared to vancomycin, metronidazole monotherapy appears less effective in curing CDI without relapse in the 027+ patient group, independently of disease severity
Human NDE1 splicing and mammalian brain development.
Exploring genetic and molecular differences between humans and other close species may be the key to explain the uniqueness of our brain and the selective pressures under which it evolves. Recent discoveries unveiled the involvement of Nuclear distribution factor E-homolog 1 (NDE1) in human cerebral cortical neurogenesis and suggested a role in brain evolution; however the evolutionary changes involved have not been investigated. NDE1 has a different gene structure in human and mouse resulting in the production of diverse splicing isoforms. In particular, mouse uses the terminal exon 8 T, while Human uses terminal exon 9, which is absent in rodents. Through chimeric minigenes splicing assay we investigated the unique elements regulating NDE1 terminal exon choice. We found that selection of the terminal exon is regulated in a cell dependent manner and relies on gain/loss of splicing regulatory sequences across the exons. Our results show how evolutionary changes in cis as well as trans acting signals have played a fundamental role in determining NDE1 species specific splicing isoforms supporting the notion that alternative splicing plays a central role in human genome evolution, and possibly human cognitive predominance
Spectrophotometric properties of dwarf planet Ceres from the VIR spectrometer on board the Dawn mission
We study the spectrophotometric properties of dwarf planet Ceres in the
VIS-IR spectral range by means of hyper-spectral images acquired by the VIR
imaging spectrometer on board the NASA Dawn mission. Disk-resolved observations
with a phase angle within the interval were used
to characterize Ceres' phase curve in the 0.465-4.05 m spectral range.
Hapke's model was applied to perform the photometric correction of the dataset,
allowing us to produce albedo and color maps of the surface. The -band
magnitude phase function of Ceres was fitted with both the classical linear
model and H-G formalism. The single-scattering albedo and the asymmetry
parameter at 0.55m are and ,
respectively (two-lobe Henyey-Greenstein phase function); the modeled geometric
albedo is ; the roughness parameter is
. Albedo maps indicate small variability
on a global scale with an average reflectance of . Isolated
areas such as the Occator bright spots, Haulani, and Oxo show an albedo much
higher than average. We measure a significant spectral phase reddening, and the
average spectral slope of Ceres' surface after photometric correction is
and at VIS and IR wavelengths, respectively.
Broadband color indices are and . H-G
modeling of the -band magnitude phase curve for gives
and , while the classical linear model provides
and . The comparison with
spectrophotometric properties of other minor bodies indicates that Ceres has a
less back-scattering phase function and a slightly higher albedo than comets
and C-type objects. However, the latter represents the closest match in the
usual asteroid taxonomy.Comment: 14 pages, 20 figures, published online on Astronomy and Astrophysics
on 13 February 2017. Revised to reflect minor changes in text and figures
made in proofs, updated value of V-R and R-
Computational Modeling of Magnesium Hydroxide Precipitation and Kinetics Parameters Identification
Magnesium is a critical raw material and its recovery as Mg(OH)2 from saltwork brines can be realized via precipitation. The effective design, optimization, and scale-up of such a process require the development of a computational model accounting for the effect of fluid dynamics, homogeneous and heterogeneous nucleation, molecular growth, and aggregation. The unknown kinetics parameters are inferred and validated in this work by using experimental data produced with a T2mm-mixer and a T3mm-mixer, guaranteeing fast and efficient mixing. The flow field in the T-mixers is fully characterized by using the k-ϵ turbulence model implemented in the computational fluid dynamics (CFD) code OpenFOAM. The model is based on a simplified plug flow reactor model, instructed by detailed CFD simulations. It incorporates Bromley’s activity coefficient correction and a micro-mixing model for the calculation of the supersaturation ratio. The population balance equation is solved by exploiting the quadrature method of moments, and mass balances are used for updating the reactive ions concentrations, accounting for the precipitated solid. To avoid unphysical results, global constrained optimization is used for kinetics parameters identification, exploiting experimentally measured particle size distribution (PSD). The inferred kinetics set is validated by comparing PSDs at different operative conditions both in the T2mm-mixer and the T3mm-mixer. The developed computational model, including the kinetics parameters estimated for the first time in this work, will be used for the design of a prototype for the industrial precipitation of Mg(OH)2 from saltwork brines in an industrial environment
Analysis of particles size distributions in Mg(OH)2 precipitation from highly concentrated MgCl2 solutions
Magnesium is a raw material of great importance, which attracted increasing interest in the last years. A promising route is to recover magnesium in the form of Magnesium Hydroxide via precipitation from highly concentrated Mg2+ resources, e.g. industrial or natural brines and bitterns. Several production methods and characterization procedures have been presented in the literature reporting a broad variety of Mg(OH)2 particle sizes. In the present work, a detailed experimental investigation is aiming to shed light on the characteristics of produced Mg(OH)2 particles and their dependence upon the reacting conditions. To this purpose, two T-shaped mixers were employed to tune and control the degree of homogenization of reactants. Particles were analysed by laser static light scattering with and without an anti-agglomerant treatment based on ultrasounds and addition of a dispersant. Zeta potential measurements were also carried out to further assess Mg(OH)2 suspension stability
A case of persistent bacteraemia by Ralstonia mannitolilytica and Ralstonia pickettii in an intensive care unit
The Ralstonia spp. genus is a group of non-fermentative, Gram-negative bacteria often resistant to many antibiotics, which are emerging as opportunistic pathogens frequently associated with infections in hospital settings. We present herein a case of combined R. pickettii and R. mannitolilytica persisting and relapsing bacteraemia, possibly caused by a septic arterial thrombosis secondary to the rupture of an internal carotid artery aneurysm. Microbiology studies showed that both Ralstonia isolates produced biofilm and carried class D oxacillinase genes. When confronted with infections caused by members of the Ralstonia genus, identification to the species level is crucial for correct clinical management, as the two species show different antibiotic susceptibility patterns
Early recognition of child abuse through screening indicators at the emergency department: experience of a tertiary urban pediatric hospital
- …