4,538 research outputs found
Forecasting COVID-19 daily cases using phone call data
The need to forecast COVID-19 related variables continues to be pressing as
the epidemic unfolds. Different efforts have been made, with compartmental
models in epidemiology and statistical models such as AutoRegressive Integrated
Moving Average (ARIMA), Exponential Smoothing (ETS) or computing intelligence
models. These efforts have proved useful in some instances by allowing decision
makers to distinguish different scenarios during the emergency, but their
accuracy has been disappointing, forecasts ignore uncertainties and less
attention is given to local areas. In this study, we propose a simple Multiple
Linear Regression model, optimised to use call data to forecast the number of
daily confirmed cases. Moreover, we produce a probabilistic forecast that
allows decision makers to better deal with risk. Our proposed approach
outperforms ARIMA, ETS and a regression model without call data, evaluated by
three point forecast error metrics, one prediction interval and two
probabilistic forecast accuracy measures. The simplicity, interpretability and
reliability of the model, obtained in a careful forecasting exercise, is a
meaningful contribution to decision makers at local level who acutely need to
organise resources in already strained health services. We hope that this model
would serve as a building block of other forecasting efforts that on the one
hand would help front-line personal and decision makers at local level, and on
the other would facilitate the communication with other modelling efforts being
made at the national level to improve the way we tackle this pandemic and other
similar future challenges.Comment: 13 pages, 7 figure
Linear and nonlinear optical responses in the chiral multifold semimetal RhSi
Chiral topological semimetals are materials that break both inversion and
mirror symmetries. They host interesting phenomena such as the quantized
circular photogalvanic effect (CPGE) and the chiral magnetic effect. In this
work, we report a comprehensive theoretical and experimental analysis of the
linear and non-linear optical responses of the chiral topological semimetal
RhSi, which is known to host multifold fermions. We show that the
characteristic features of the optical conductivity, which display two distinct
quasi-linear regimes above and below 0.4 eV, can be linked to excitations of
different kinds of multifold fermions. The characteristic features of the CPGE,
which displays a sign change at 0.4 eV and a large non-quantized response peak
of around 160 at 0.7 eV, are explained by assuming that
the chemical potential crosses a flat hole band at the Brillouin zone center.
Our theory predicts that, in order to observe a quantized CPGE in RhSi, it is
necessary to increase the chemical potential as well as the quasiparticle
lifetime. More broadly our methodology, especially the development of the
broadband terahertz emission spectroscopy, could be widely applied to study
photo-galvanic effects in noncentrosymmetric materials and in topological
insulators in a contact-less way and accelerate the technological development
of efficient infrared detectors based on topological semimetals.Comment: Accepted in npj Quantum Materials; Abstract update
Digital Disconnection as an Opportunity for the Tourism Business: A Bibliometric Analysis
The aim of this study is to carry out a bibliometric review of the existing research on digital disconnection and Digital Free Tourism (DFT) to discover the extent to which this new trend affects technology users and the tourism market. To do this, a systematic literature review and a bibliometric analysis of the research on digital disconnection contained in the Scopus and Web of Science databases were used. This research includes publications from 2012 to December 2021, which included a total of 37 publications about digital disconnection and digital free tourism in scientific journals indexed in the main scientific databases. The analysis concludes that DFT is a growing economic trend in research and that the phenomenon of digital disconnection is beginning to be a peremptory need for more and more users. This work is original and interesting for researchers specialising in technology addictions, as well as academics and professionals in the tourism sector, because the extensive use of smart devices is becoming a type of addiction in many areas and can be a new opportunity for the tourism market. The DFT phenomenon can improve the response to these types of addictions and be a temporary escape and alternative to technological devices. Doi: 10.28991/ESJ-2022-06-05-013 Full Text: PD
Spectroscopic Links Among Giant Planet Irregular Satellites and Trojans
We collect near-infrared spectra () of four Jovian
irregular satellites and visible spectra () of two Jovian
irregular satellites, two Uranian irregular satellites, and four Neptune
Trojans. We find close similarities between observed Jovian irregular
satellites and previously characterized Jovian Trojans. However, irregular
satellites' unique collisional histories complicate comparisons to other
groups. Laboratory study of CM and CI chondrites show that grain size and
regolith packing conditions strongly affect spectra of dark, carbonaceous
materials. We hypothesize that different activity histories of these objects,
which may have originally contained volatile ices that subsequently sublimated,
could cause differences in regolith grain-size or packing properties and
therefore drive spectral variation. The Uranian satellites Sycorax and Caliban
appear similar to TNOs. However, we detect a feature near 0.7 on
Sycorax, suggesting the presence of hydrated materials. While the sample of
Neptune Trojans have more neutral spectra than the Uranian satellites we
observe, they remain consistent with the broad color distribution of the Kuiper
belt. We detect a possible feature near 0.65-0.70 on Neptune Trojan
2006 RJ103, suggesting that hydrated material may also be present in this
population. Characterizing hydrated materials in the outer solar system may
provide critical context regarding the origins of hydrated CI and CM chondrite
meteorites. We discuss how the hydration state(s) of the irregular satellites
constrains the thermal histories of the interiors of their parent bodies, which
may have formed among the primordial Kuiper belt.Comment: 4 Tables, 8 Figures. Accepted to PS
Sistema de Gestión Integral de Residuos en una Empresa Automotriz
A medida que el mundo ha ido evolucionando, la sociedad ha ido cambiando sus esquemas de
consumo y producción, el mundo se ha tornado más productivo para sostener la demanda de la
sociedad actual y a su vez, los productos y residuos han aumentado su ciclo de vida, se han
tornado cada vez más complejos por su composición, antes los residuos era más de composición
orgánica, hoy es más compleja lo que trae como consecuencia un aumento en los volúmenes
siendo una preocupación la gestión de residuos a nivel mundial, haciéndose un tema de gran
preocupación no sólo para el gobierno, sino también para las organizaciones no gubernamentales.
La industria automotriz a nivel nacional, es el sector productivo que ocupa el tercer lugar en
generación de residuos peligrosos por ello, se implementa un Sistema de Gestión Integral de
Residuos, realizando un diagrama de proceso desde el inicio del proceso, analizando entradas y
salidas a las entradas de la materia prima haciendo compras razonables con el enfoque de evitar que
los residuos sean generados, hacer comprar más amigables al ambiente con el menor impacto
ambiental, con menos empaque, con el menor riesgo posible al ambiente y al personal involucrado,
por ello, como parte de la mejora continua, explícito en la norma ISO 14001:2004 en su elemento
4.1, se hace un análisis de entradas y salidas en una empresa automotriz, desde que inicia el
proceso hasta que termina para determinar, categorizar y cuantificar los residuos peligrosos y de
manejo especial realizando un sistema de gestión integral con un enfoque de prevención,
minimización, reúso, reciclo, tratamiento, coprocesamiento o conexión a otro proceso, dejando al
último el confinamiento que vaya más allá de un simple cumplimiento legal donde no solo lo
ambiental se vea favorecido si no también lo económico y lo social
Prevalence of and Factors Associated with Negative Microscopic Diagnosis of Cutaneous Leishmaniasis in Rural Peru.
Cutaneous leishmaniasis is endemic to South America where diagnosis is most commonly conducted via microscopy. Patients with suspected leishmaniasis were referred for enrollment by the Ministry of Health (MoH) in Lima, Iquitos, Puerto Maldonado, and several rural areas of Peru. A 43-question survey requesting age, gender, occupation, characterization of the lesion(s), history of leishmaniasis, and insect-deterrent behaviors was administered. Polymerase chain reaction (PCR) was conducted on lesion materials at the Naval Medical Research Unit No. 6 in Lima, and the results were compared with those obtained by the MoH using microscopy. Factors associated with negative microscopy and positive PCR results were identified using
Continuous multi-criteria methods for crop and soil conservation planning on La Colacha (Río Cuarto, Province of Cordoba, Argentina)
Agro-areas of Arroyos Menores (La Colacha) west and south of Rand south of R?o Cuarto (Prov. of Cordoba, Argentina) basins are very fertile but have high soil loses. Extreme rain events, inundations and other severe erosions forming gullies demand urgently actions in this area to avoid soil degradation and erosion supporting good levels of agro production. The authors first improved hydrologic data on La Colacha, evaluated the systems of soil uses and actions that could be recommended considering the relevant aspects of the study area and applied decision support systems (DSS) with mathematic tools for planning of defences and uses of soils in these areas. These were conducted here using multi-criteria models, in multi-criteria decision making (MCDM); first of discrete MCDM to chose among global types of use of soils, and then of continuous MCDM to evaluate and optimize combined actions, including repartition of soil use and the necessary levels of works for soil conservation and for hydraulic management to conserve against erosion these basins. Relatively global solutions for La Colacha area have been defined and were optimised by Linear Programming in Goal Programming forms that are presented as Weighted or Lexicographic Goal Programming and as Compromise Programming. The decision methods used are described, indicating algorithms used, and examples for some representative scenarios on La Colacha area are given
Non-Invasive Assessment of Pulmonary Vasculopathy
Right heart catheterization remains necessary for the diagnosis of pulmonary hypertension and, therefore, for the prognostic evaluation of patients with chronic heart failure. The non-invaSive Assessment of Pulmonary vasculoPathy in Heart failure (SAPPHIRE) study was designed to assess the feasibility and prognostic relevance of a non-invasive evaluation of the pulmonary artery vasculature in patients with heart failure and pulmonary hypertension. Patients will undergo a right heart catheterization, cardiac resonance imaging, and a pulmonary function test in order to identify structural and functional parameters allowing the identification of combined pre- and postcapillary pulmonary hypertension, and correlate these findings with the hemodynamic dataThis research was funded by European Regional Development Fund and the Carlos III Research Institute through a grant of the Health Strategy Action (PI17/01569).S
Biomarker and Histopathology Evaluation of Patients with Recurrent Glioblastoma Treated with Galunisertib, Lomustine, or the Combination of Galunisertib and Lomustine
Galunisertib, a Transforming growth factor-βRI (TGF-βRI) kinase inhibitor,
blocks TGF-β-mediated tumor growth in glioblastoma. In a three-arm study of
galunisertib (300 mg/day) monotherapy (intermittent dosing; each cycle =14
days on/14 days off), lomustine monotherapy, and galunisertib plus lomustine
therapy, baseline tumor tissue was evaluated to identify markers associated
with tumor stage (e.g., histopathology, Ki67, glial fibrillary acidic protein)
and TGF-β-related signaling (e.g., pSMAD2). Other pharmacodynamic assessments
included chemokine, cytokine, and T cell subsets alterations. 158 patients
were randomized to galunisertib plus lomustine (n = 79), galunisertib (n = 39)
and placebo+lomustine (n = 40). In 127 of these patients, tissue was adequate
for central pathology review and biomarker work. Isocitrate dehydrogenase
(IDH1) negative glioblastoma patients with baseline pSMAD2+ in cytoplasm had
median overall survival (OS) 9.5 months vs. 6.9 months for patients with no
tumor pSMAD2 expression (p = 0.4574). Eight patients were IDH1 R132H+ and had
a median OS of 10.4 months compared to 6.9 months for patients with negative
IDH1 R132H (p = 0.5452). IDH1 status was associated with numerically higher
plasma macrophage-derived chemokine (MDC/CCL22), higher whole blood FOXP3, and
reduced tumor CD3+ T cell counts. Compared to the baseline, treatment with
galunisertib monotherapy preserved CD4+ T cell counts, eosinophils,
lymphocytes, and the CD4/CD8 ratio. The T-regulatory cell compartment was
associated with better OS with MDC/CCL22 as a prominent prognostic marker.
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