304 research outputs found
I segmenti storico-militari nel«Devisement dou monde» di Marco Polo: analisi morfologica
The paper aims to: 1) define a poetics of narration and representation in Polo’s Devisement dou monde by means of a morphological and stylistic analysis of the battle scenes included in the book; 2) make a comparison with the meslee scenes in Rustichello’s Compilation arthurienne (around 1270-1274), in order to show how the Pisan romance writer, who co-authored the Milione with the Venetian traveller (Genoa, 1298), crafted the partes historiales of their livre, blending chivalric fiction and historical fragments. The study is enriched with one or two references to the Mongolian Secret History of the Mongols (probably 1228)
Predicción del Net Promoter Score ante la falta de encuestas
Para poder retener a los clientes de la compañía es clave que las interacciones con la misma generen buenas experiencias. Una de las principales métricas utilizadas para medir la experiencia de los clientes es el Net Promoter Score (NPS). Este indicador se construye a partir de las encuestas que contestan los clientes. En una plataforma de comercio electrónico, el NPS de los compradores nos permite conocer la experiencia de compra en la plataforma y la performance de los vendedores a la hora de transaccionar. Se puede saber si un vendedor está ofreciendo una experiencia satisfactoria a sus clientes y cumpliendo con los estándares pretendidos por la plataforma mirando el NPS que surge de las encuestas que contestan sus compradores. Sin embargo, para garantizar la representatividad y robustez del indicador, es necesario contar con una base mínima de respuestas que no siempre puede obtenerse. En la presente tesis se propone una alternativa de solución ante la falta de encuestas: un algoritmo de Ridge que utiliza diferentes variables transaccionales y asociadas a los usuarios para poder predecir el NPS. El algoritmo propuesto demostró tener mejor performance que la solución vigente en la empresa. Adicionalmente, permite contar diariamente con un valor de NPS para que los empleados de la empresa encargados de asesorar a los vendedores de la plataforma puedan contar con un KPI que les permita detectar desviaciones en la experiencia ofrecida
Binary black hole spins: model selection with GWTC-3
The origin of the spins of stellar-mass black holes is still controversial,
and angular momentum transport inside massive stars is one of the main sources
of uncertainty. Here, we apply hierarchical Bayesian inference to derive
constraints on spin models from the 59 most confident binary black hole merger
events in the third gravitational-wave transient catalogue (GWTC-3). We
consider up to five parameters: chirp mass, mass ratio, redshift, effective
spin, and precessing spin. For model selection, we use a set of binary
population synthesis simulations spanning drastically different assumptions for
black hole spins and natal kicks. In particular, our spin models range from
maximal to minimal efficiency of angular momentum transport in stars. We find
that, if we include the precessing spin parameter into our analysis, models
predicting only vanishingly small spins are in tension with GWTC-3 data. On the
other hand, models in which most spins are vanishingly small, but that also
include a sub-population of tidally spun-up black holes are a good match to the
data. Our results show that the precessing spin parameter has a crucial impact
on model selection.Comment: 11 pages, submitted to mnras. arXiv admin note: text overlap with
arXiv:2102.12495 by same author
The cosmic merger rate density of compact objects: impact of star formation, metallicity, initial mass function and binary evolution
We evaluate the redshift distribution of binary black hole (BBH), black hole
- neutron star binary (BHNS) and binary neutron star (BNS) mergers, exploring
the main sources of uncertainty: star formation rate (SFR) density, metallicity
evolution, common envelope, mass transfer via Roche lobe overflow, natal kicks,
core-collapse supernova model and initial mass function. Among binary evolution
processes, uncertainties on common envelope ejection have a major impact: the
local merger rate density of BNSs varies from to
Gpc yr if we change the common envelope efficiency parameter from
to 0.5, while the local merger rates of BBHs and BHNSs vary
by a factor of . The BBH merger rate changes by one order of
magnitude, when uncertainties on metallicity evolution are taken
into account. In contrast, the BNS merger rate is almost insensitive to
metallicity. Hence, BNSs are the ideal test bed to put constraints on uncertain
binary evolution processes, such as common envelope and natal kicks. Only
models assuming values of and moderately low natal
kicks (depending on the ejected mass and the SN mechanism), result in a local
BNS merger rate density within the 90% credible interval inferred from the
second gravitational-wave transient catalogue.Comment: 14 pages, 12 figures, 2 tables, accepted for publication in MNRA
Refining diagnosis and management of chronic venous disease: Outcomes of a modified Delphi consensus process
Abstract Chronic venous disease (CVD) is a common condition with major health consequences that is associated with poor long-term prognosis, significant socioeconomic impact, disabling symptoms and reduced quality of life. To provide practical guidance for diagnosis and management of CVD, a Delphi panel of 5 experts in steering committee and 28 angiologists/vascular surgeons met with the major aim of providing a supplement for established national and international guidelines. A total of 24 statements were voted upon in two rounds, of which consensus was reached on 22 statements, indicating a high level of overall agreement. Consensus was reached on 7 of 8 statements relative to diagnosis (CEAP classification, diagnostic tools, QoL assessment, diagnostic imaging) and on 15 of 16 statements on management (conservative treatments, compressive therapy, pharmacological therapy, surgical treatment). The results of the consensus reached are discussed herein from which it is clear that diagnostic and management approaches utilising personalised therapies tailored to the individual patient should be favoured. While it is clear that additional studies are needed on many aspects of diagnosis and management of CVD, the present Delphi survey provides some key recommendations for clinicians treating CVD that may be useful in daily practice
La Danzatrice Araba
Title Onlyhttps://scholarsjunction.msstate.edu/cht-sheet-music/8015/thumbnail.jp
Host galaxies of merging compact objects: mass, star formation rate, metallicity, and colours
Characterizing the properties of the host galaxies of merging compact objects provides essential clues to interpret current and future gravitational-wave detections. Here, we investigate the stellar mass, star formation rate (SFR), metallicity, and colours of the host galaxies of merging compact objects in the local Universe by combining the results of MOBSE population-synthesis models together with galaxy catalogues from the EAGLE simulation. We predict that the stellar mass of the host galaxy is an excellent tracer of the merger rate per galaxy n(GW) of double neutron stars (DNSs), double black holes (DBHs), and
black hole-neutron star binaries (BHNSs). We find a significant correlation also between n(GW) and SFR. As a consequence, n(GW) correlates also with the r-band luminosity and with the g-r colour of the host galaxies. Interestingly, greater than or similar to 60 per
cent, greater than or similar to 64 per cent, and greater than or similar to 73 per cent of all the DNSs, BHNSs, and DBHs merging in the local Universe lie in early-type galaxies, such as NGC 4993. We predict a local DNS merger rate density of similar to 238 Gpc(-3) yr(-1) and a
DNS merger rate similar to 16-121 Myr(-1) for Milky Way-like galaxies. Thus, our results are consistent with both the DNS merger rate inferred from GW170817 and the one inferred from Galactic DNSs
Delphi case: Sharing of clinical experiences for improvement in the treatment of chronic venous disease
Chronic venous disease (CVD) is a common condition with major health consequences that is associated with poor long-term prognosis, significant socioeconomic impact, disabling symptoms, and reduced quality of life. To provide a novel evidence-based approach in the management of CVD, a consensus process (“Delphi Case”) following a first Delphi Consensus was conceived. With a real-life fashion analysis, a steering committee formed by 3 expert leaders on chronic venous disease drove a panel of 77 expert Italian angiologists/vascular surgeons along a collegial discussion, integrating data coming from the guidelines recommendations of different Vascular Scientific Societies with the consensus agreement statements gathered from the first Delphi Consensus, and with data coming from the discussion of few statements in which there was disagreement. From July 15 to October 16, 2020, demographic, anamnestic, objective, and therapeutic data coming from a total of 2,275 patients were collected by the experts panel using a predefined case report form. The results of this second consensus provided a real-life picture of CVD management in the Italian population and clearly showed that a tailored therapeutic approach together with an appropriate lifestyle (e.g., diet, physical activity, weight loss) must be considered as the milestones for the CVD-related signs and symptoms clinical improvement in daily clinical practice. An evaluation of the adherence and of the efficacy of the prescribed pharmacological and compressive treatment in a medium-long term follow-up of the study population has been planned as the last step of this course and will be object of a future final publication
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