312 research outputs found
Design Product-Service Systems by Using a Hybrid Approach: The Fashion Renting Business Model
As is known, sustainability issues represent one of the main challenges companies have to face. Among all, the fashion industry is considered one of the most impactful, both in terms of resource utilization and pollution. Fashion renting is a recent business model for companies to reduce their environmental footprint, following a circular economy approach. The study aims to develop and discuss the proposed hybrid approach to effectively support fashion companies in designing new business models, taking into account both the customer and the company perspective. On the one hand, agent-based modeling (ABM) allow us to represent customers’ behaviour and interaction. On the other hand, discrete event simulation (DES) paradigm is used to model fashion renting processes. Because customers’ attitude to that service reflects its successful implementation, motivators and barriers have been investigated to be included in the model. The practical implication is defining a model to support fashion companies in designing rental business models before implementing them. From a theoretical point of view, it overcomes the literature gap about the definition of a unique model for fashion renting, including processes, customers and interactions between agents. Follow-up research will include the presentation of simulation results
Testing one-loop galaxy bias: Cosmological constraints from the power spectrum
We investigate the impact of different assumptions in the modeling of one-loop galaxy bias on the recovery of cosmological parameters, as a follow-up of the analysis done in the first paper of the series at fixed cosmology. To carry out these tests we focus on the real-space galaxy-power spectrum from a set of three different synthetic galaxy samples whose clustering properties are meant to match the ones of the CMASS and LOWZ catalogs of BOSS and the SDSS Main Galaxy Sample. We investigate the relevance of allowing for either short range nonlocality or scale-dependent stochasticity by fitting the real-space galaxy autopower spectrum or the combination of galaxy-galaxy and galaxy-matter power spectrum. From a comparison among the goodness of fit (χ2), unbiasedness of cosmological parameters (FoB), and figure of merit (FoM) of the model, we find that a simple four-parameter model (linear, quadratic, cubic nonlocal bias, and constant shot noise) with fixed quadratic tidal bias provides a robust modeling choice for the autopower spectrum of the three galaxy samples, up to kmax ¼ 0.3h Mpc−1 and for an effective volume of 6h−3 Gpc3. Instead, a joint analysis of the two observables fails at larger scales, and a model extension with either higher derivatives or scale-dependent shot noise is necessary to reach a similar kmax, with the latter providing the most accurate and stable results. Throughout the majority of the paper, we fix the description of the nonlinear matter evolution using a hybrid perturbative-N-body approach, RESPRESSO, that was found in the first paper to be the closest performing to the measured matter spectrum. We also test the impact of different modeling assumptions based on perturbative approaches, such as galilean-invariant Renormalised Perturbation Theory (gRPT) and effective field theory (EFT). In all cases, we find the inclusion of scale-dependent shot noise to increase the range of validity of the model in terms of FoB and χ2. Interestingly, these model extensions with additional free parameters do not necessarily lead to an increase in the maximally achievable FoM for the cosmological parameters ðh; Ωch2; AsÞ, which are generally consistent with those of the simpler model at smaller kmax
Momentum dependence of orbital excitations in Mott-insulating titanates
High-resolution resonant inelastic x-ray scattering has been used to
determine the momentum dependence of orbital excitations in Mott-insulating
LaTiO and YTiO over a wide range of the Brillouin zone. The data are
compared to calculations in the framework of lattice-driven and
superexchange-driven orbital ordering models. A superexchange model in which
the experimentally observed modes are attributed to two-orbiton excitations
yields the best description of the data.Comment: to appear in PR
Endoscopic Resection of Esophageal Lymphangioma Incidentally Discovered
A pedunculated lymphangioma of the esophagus was unexpectedly discovered during an
endoscopic investigation performed for epigastric pain in a patient affected by diabetic
arteriopathy treated with antiplatelet drugs. The patient neither complained of dysphagia
nor other symptoms related to the presence of the lymphangioma which therefore can be
considered as an endoscopic “incidentaloma”
COMET: Clustering Observables Modelled by Emulated perturbation Theory
In this paper we present COMET, a Gaussian process emulator of the galaxy
power spectrum multipoles in redshift-space. The model predictions are based on
one-loop perturbation theory and we consider two alternative descriptions of
redshift-space distortions: one that performs a full expansion of the real- to
redshift-space mapping, as in recent effective field theory models, and another
that preserves the non-perturbative impact of small-scale velocities by means
of an effective damping function. The outputs of COMET can be obtained at
arbitrary redshifts (up to ), for arbitrary fiducial background
cosmologies, and for a large parameter space that covers the shape parameters
, , and , as well as the evolution parameters ,
, , , and . This flexibility does not impair COMET's
accuracy, since we exploit an exact degeneracy between the evolution parameters
that allows us to train the emulator on a significantly reduced parameter
space. While the predictions are sped up by at least two orders of magnitude,
validation tests reveal an accuracy of for the monopole and
quadrupole ( for the hexadecapole), or alternatively, better than
for all three multipoles in comparison to statistical
uncertainties expected for the Euclid survey with a tenfold increase in volume.
We show that these differences translate into shifts in mean posterior values
that are at most of the same size, meaning that COMET can be used with the same
confidence as the exact underlying models. COMET is a publicly available Python
package that also provides the tree-level bispectrum multipoles in
redshift-space and Gaussian covariance matrices.Comment: 18 pages, 10 figures; for the COMET Python package, see
https://gitlab.com/aegge/comet-em
Genetic model for the color anomalies at the termination of pegmatitic gem tourmaline crystals from the island of Elba, Italy
Tourmaline crystals from the island of Elba commonly display a
sharp transition to dark colors at the analogous termination due to the
incorporation of Fe and/or Mn during the latest stages of crystallization
in pegmatites. The formation of such color anomalies is related to a
dramatic physicochemical change in the crystallization environment as a
consequence of an opening of the geochemical system. However, mechanisms
that may lead to the availability of Fe and/or Mn in the residual cavity fluids
have been unclear. On the basis of chemical and spectroscopic
investigations, combined with structural and paragenetic observations of the
cavities, we propose a general genetic model in which, as a consequence of a
pocket rupture event, chemical alteration of Fe- and Mn-rich
minerals that formed early in the pegmatitic rock surrounding the cavities occurred through
leaching processes, produced by the action of the highly reactive late-stage
cavity fluids. Such processes were responsible for the release of Fe and Mn
in the geochemical system, allowing the formation of the late-stage dark-colored terminations in the tourmaline crystals. In some cavities, a high
availability of Mn and/or Fe determined the evolution of the crystals from
an initial elbaite/fluor-elbaite composition to celleriite, foitite or
schorl. This compositional evolution trend can be described by the following general
chemical substitution: XNa+ + Y(Li1.5 + Al0.5)3+ + WF− ↔ X□ + 2Y(Fe,Mn)2+ + WOH−.</p
Beyond CDM constraints from the full shape clustering measurements from BOSS and eBOSS
We analyse the full shape of anisotropic clustering measurements from the
extended Baryon Oscillation Spectroscopic survey (eBOSS) quasar sample together
with the combined galaxy sample from the Baryon Oscillation Spectroscopic
Survey (BOSS). We obtain constraints on the cosmological parameters independent
of the Hubble parameter for the extensions of the CDM models,
focusing on cosmologies with free dark energy equation of state parameter .
We combine the clustering constraints with those from the latest CMB data from
Planck to obtain joint constraints for these cosmologies for and the
additional extension parameters - its time evolution , the physical
curvature density and the neutrino mass sum . Our
joint constraints are consistent with flat CDM cosmological model
within 68\% confidence limits. We demonstrate that the Planck data are able to
place tight constraints on the clustering amplitude today, , in
cosmologies with varying and present the first constraints for the
clustering amplitude for such cosmologies, which is found to be slightly higher
than the CDM value. Additionally, we show that when we vary and
allow for non-flat cosmologies and the physical curvature density is used,
Planck prefers a curved universe at significance, which is
higher than when using the relative curvature density
. Finally, when is varied freely, clustering provides only
a modest improvement (of 0.021 eV) on the upper limit of .Comment: 12 pages, 6 figures, submitted to MNRA
Dysregulation of NIPBL leads to impaired RUNX1 expression and hematopoietic defects
The transcription factor RUNX1, a pivotal regulator of HSCs and haematopoiesis, is a frequent target of chromosomal translocations, point mutations or altered gene/protein dosage. These modifications lead or contribute to the development of myelodysplasia, leukaemia or platelet disorders. A better understanding of how regulatory elements contribute to fine-tune the RUNX1 expression in haematopoietic tissues could improve our knowledge of the mechanisms responsible for normal haematopoiesis and malignancy insurgence. The cohesin RAD21 was reported to be a regulator of RUNX1 expression in the human myeloid HL60 cell line and during primitive haematopoiesis in zebrafish. In our study, we demonstrate that another cohesin, NIPBL, exerts positive regulation of RUNX1 in three different contexts in which RUNX1 displays important functions: in megakaryocytes derived from healthy donors, in bone marrow samples obtained from adult patients with acute myeloid leukaemia and during zebrafish haematopoiesis. In this model, we demonstrate that alterations in the zebrafish orthologue nipblb reduce runx1 expression with consequent defects in its erythroid and myeloid targets such as gata1a and spi1b in an opposite way to rad21. Thus, also in the absence of RUNX1 translocation or mutations, additional factors such as defects in the expression of NIPBL might induce haematological diseases
Gem-Quality Tourmaline from LCT Pegmatite in Adamello Massif, Central Southern Alps, Italy: An Investigation of Its Mineralogy, Crystallography and 3D Inclusions
In the early 2000s, an exceptional discovery of gem-quality multi-coloured tourmalines, hosted in Litium-Cesium-Tantalum (LCT) pegmatites, was made in the Adamello Massif, Italy. Gem-quality tourmalines had never been found before in the Alps, and this new pegmatitic deposit is of particular interest and worthy of a detailed characterization. We studied a suite of faceted samples by classical gemmological methods, and fragments were studied with Synchrotron X-ray computed micro-tomography, which evidenced the occurrence of inclusions, cracks and voids. Electron Microprobe combined with Laser Ablation analyses were performed to determine major, minor and trace element contents. Selected samples were analysed by single crystal X-ray diffraction method. The specimens range in colour from colourless to yellow, pink, orange, light blue, green, amber, brownish-pink, purple and black. Chemically, the tourmalines range from fluor-elbaite to fluor-liddicoatite and rossmanite: these chemical changes occur in the same sample and affect the colour. Rare Earth Elements (REE) vary from 30 to 130 ppm with steep Light Rare Earth Elemts (LREE)-enriched patterns and a negative Eu-anomaly. Structural data confirmed the elbaitic composition and showed that high manganese content may induce the local static disorder at the O(1) anion site, coordinating the Y cation sites occupied, on average, by Li, Al and Mn2+ in equal proportions, confirming previous findings. In addition to the gemmological value, the crystal-chemical studies of tourmalines are unanimously considered to be a sensitive recorder of the geological processes leading to their formation, and therefore, this study may contribute to understanding the evolution of the pegmatites related to the intrusion of the Adamello pluton
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