207 research outputs found

    The cosmic evolution of the spatially-resolved star formation rate and stellar mass of the CALIFA survey

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    We investigate the cosmic evolution of the absolute and specific star formation rate (SFR, sSFR) of galaxies as derived from a spatially-resolved study of the stellar populations in a set of 366 nearby galaxies from the CALIFA survey. The analysis combines GALEX and SDSS images with the 4000 break, H_beta, and [MgFe] indices measured from the datacubes, to constrain parametric models for the SFH, which are then used to study the cosmic evolution of the star formation rate density (SFRD), the sSFR, the main sequence of star formation (MSSF), and the stellar mass density (SMD). A delayed-tau model, provides the best results, in good agreement with those obtained from cosmological surveys. Our main results from this model are: a) The time since the onset of the star formation is larger in the inner regions than in the outer ones, while tau is similar or smaller in the inner than in the outer regions. b) The sSFR declines rapidly as the Universe evolves, and faster for early than for late type galaxies, and for the inner than for the outer regions of galaxies. c) SFRD and SMD agree well with results from cosmological surveys. At z< 0.5, most star formation takes place in the outer regions of late spiral galaxies, while at z>2 the inner regions of the progenitors of the current E and S0 are the major contributors to SFRD. d) The inner regions of galaxies are the major contributor to SMD at z> 0.5, growing their mass faster than the outer regions, with a lookback time at 50% SMD of 9 and 6 Gyr for the inner and outer regions. e) The MSSF follows a power-law at high redshift, with the slope evolving with time, but always being sub-linear. f) In agreement with galaxy surveys at different redshifts, the average SFH of CALIFA galaxies indicates that galaxies grow their mass mainly in a mode that is well represented by a delayed-tau model, with the peak at z~2 and an e-folding time of 3.9 Gyr.Comment: 23 pages, 16 figures, 6 tables, accepted for publication in Astronomy & Astrophysics. *Abridged abstract

    Link layer Connectivity as a Service for Ad-hoc Microservice Platforms

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    Microservice platforms have brought many advantages to support the deployment of light-weight applications at both near the edge and data centers. Still, their suitability to support telecommunication and vertical services beyond the network edge is far from being a reality. On one hand, their flat networking approach does not support the establishment of link-layer connectivity among the different components of telecommunication and vertical services (e.g., access points, routers, specific-purpose servers, etc.) due to their reliance on high-level APIs. On the other hand, their networking approach has not been designed to operate over ad hoc networks built by the resource-constrained devices that may be available beyond the network edge. This can lead to suboptimal behaviors for the delivery of data traffic between microservices. This article presents the results of a research collaboration between Universidad Carlos III of Madrid and TelefĂłnica: L2S-M. Our solution provides a programmable data plane that enables the establishment of on-demand link layer connectivity between microservices on ad hoc networks. This solution has the flexibility to execute different algorithms to build traffic paths between microservices, as well as to react against temporary link breakdowns, which could be present in these types of networks. The article presents a proof of concept for a functional validation of L2S-M, using an aerial ad hoc network deployed at 5TONIC Laboratory in collaboration with Telefonica. The validation results showcase the proper operation of L2S-M as a networking service for microservice platforms in ad hoc networks, including its ability to reconfigure the programmable data plane when link disruptions occur.This article has been supported by the TRUE5G (PID2019-108713RB681) project funded by the Spanish National Research Agency (MCIN/AEI/10.13039/5011000110) and by the H2020 FISHY Project (Grant agreement ID: 952644)

    The emotional well-being of Long COVID patients in relation to their symptoms, social support and stigmatization in social and health services: a qualitative study

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    Background Long COVID patients have experienced a decline in their quality of life due to, in part but not wholly, its negative emotional impact. Some of the most prevalent mental health symptoms presented by long COVID patients are anxiety, depression, and sleep disorders. As such, the need has arisen to analyze the personal experiences of these patients to understand how they are managing their daily lives while dealing with the condition. The objective of this study is to increase understanding about the emotional well-being of people diagnosed with long COVID. Methods A qualitative design was created and carried out using 35 patients, with 17 participants being interviewed individually and 18 of them taking part in two focus groups. The participating patients were recruited in November and December 2021 from Primary Health Care (PHC) centers in the city of Zaragoza (Northern Spain) and from the Association of Long COVID Patients in Aragon. The study topics were emotional well-being, social support networks, and experience of discrimination. All an inductive thematic content analyses were performed iteratively using NVivo software. Results The Long COVID patients identified low levels of self-perceived well-being due to their persistent symptoms, as well as limitations in their daily lives that had been persistent for many months. Suicidal thoughts were also mentioned by several patients. They referred to anguish and anxiety about the future as well as a fear of reinfection or relapse and returning to work. Many of the participants reported that they have sought the help of a mental health professional. Most participants identified discriminatory situations in health care. Conclusions It is necessary to continue researching the impact that Long COVID has had on mental health, as well as to provide Primary Health Care professionals with evidence that can guide the emotional treatment of these patients

    Effectiveness of a telerehabilitation intervention using ReCOVery APP of long COVID patients: a randomized, 3-month follow-up clinical trial

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    The main objective of this study is to analyze the clinical efficacy of telerehabilitation in the recovery of Long COVID patients through ReCOVery APP for 3 months, administered in the Primary Health Care context. The second objective is to identify significant models associated with an improvement in the study variables. An open-label randomized clinical trial was conducted using two parallel groups of a total of 100 Long COVID patients. The first group follows the treatment as usual methods established by their general practitioner (control group) and the second follows the same methods and also uses ReCOVery APP (intervention group). After the intervention, no significant differences were found in favour of the group intervention. Regarding adherence, 25% of the participants made significant use of the APP. Linear regression model establishes that the time of use of ReCOVery APP predicts an improvement in physical function (b = 0.001; p = 0.005) and community social support (b = 0.004; p = 0.021). In addition, an increase in self-efficacy and health literacy also contribute to improving cognitive function (b = 0.346; p = 0.001) and reducing the number of symptoms (b = 0.226; p = 0.002), respectively. In conclusion, the significant use of ReCOVery APP can contribute to the recovery of Long COVID patients. Trial Registration No.: ISRCTN91104012

    NFV orchestration on intermittently available SUAV platforms: challenges and hurdles

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    Proceeding of: IEEE INFOCOM 2019 - IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS MiSARN 2019: Mission-Oriented Wireless Sensor, UAV and Robot Networking), 29 April-2 May 2019 Paris, FranceIn this paper, we analyze the main challenges and issues related with the orchestration of Virtualized Network Functions (VNFs) on Small Unmanned Aerial Vehicles (SUAVs). Our analysis considers a reference scenario where a number of SUAVs are deployed over a delimited geographic area and provide a mobile cloud environment that supports the deployment of functionalities using Network Functions Virtualization (NFV) technologies. The orchestration of services in this reference scenario presents different challenges, due to the constrained capacity and limited lifetime of battery-powered SUAVs, the intermittent availability of network communications, and the need to consider enhanced policies for the allocation of virtual functions to SUAVs. Finally, we perform a first exploratory evaluation of the identified challenges and issues, using a well-known and widely adopted virtualized infrastructure manager, i.e., OpenStack.This article has been partially supported by the European H2020 5GRANGE project (grant agreement 777137), and by the 5GCity project (TEC2016-76795- C6-3-R) funded by the Spanish Ministry of Economy and Competitiveness

    Modulation of the electroluminescence emission from ZnO/Si NCs/p-Si light-emitting devices via pulsed excitation

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    In this work, the electroluminescence (EL) emission of zinc oxide (ZnO)/Si nanocrystals (NCs)-based light-emitting devices was studied under pulsed electrical excitation. Both Si NCs and deep-level ZnO defects were found to contribute to the observed EL. Symmetric square voltage pulses (50-ÎĽs period) were found to notably enhance EL emission by about one order of magnitude. In addition, the control of the pulse parameters (accumulation and inversion times) was found to modify the emission lineshape, long inversion times (i.e., short accumulation times) suppressing ZnO defects contribution. The EL results were discussed in terms of the recombination dynamics taking place within the ZnO/Si NCs heterostructure, suggesting the excitation mechanism of the luminescent centers via a combination of electron impact, bipolar injection, and sequential carrier injection within their respective conduction regimes

    The impact of the COVID-19 lockdown on depression sufferers: a qualitative study from the province of Zaragoza, Spain

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    Background and purpose: The impact of COVID-19 and its control measures have exacerbated existing mental health conditions. Although the deleterious effects of mental health problems are well known, fewer studies have examined the links between the Social Determinants of Health (SDHs) and depression. This study provides insights into the relationship between SDHs and depression during the first strict lockdown in Spain, which lasted for a period of 7 weeks. Methods: Fifty-two structured interviews were conducted with people diagnosed with depression during June 2020 in the province of Zaragoza (Spain). Interviews were conducted by telephone due to lockdown constraints. Inductive thematic content analysis was used to explore, develop, and define emergent categories of analysis, which were mapped against the SDH framework. Results: Listening to people’s experiences of living with depression during lockdown provided insights into their concerns and coping strategies, which are greatly influenced by the conditions in which they live, their job and their age. Examples of these factors include access to and quality of physical spaces, including housing conditions and public spaces for socialising, social support, adverse working conditions which include caring responsibilities, and access to digital technologies and healthcare services. Conclusion: SDHs have played a fundamental role in shaping people’s health and well-being during the COVID-19 pandemic, and this study has shown that they have a considerable effect on depression outcomes. Governments should consider implementing social welfare programs to tackle both psychosocial problems and material need during crisis situations

    Insights on the stellar mass-metallicity relation from the CALIFA survey

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    We use spatially and temporally resolved maps of stellar population properties of 300 galaxies from the CALIFA integral field survey to investigate how the stellar metallicity (Z*) relates to the total stellar mass (M*) and the local mass surface density (μ\mu*) in both spheroidal and disk dominated galaxies. The galaxies are shown to follow a clear stellar mass-metallicity relation (MZR) over the whole 109^9 to 1012^{12} M⊙_{\odot} range. This relation is steeper than the one derived from nebular abundances, which is similar to the flatter stellar MZR derived when we consider only young stars. We also find a strong relation between the local values of μ\mu* and Z* (the μ\muZR), betraying the influence of local factors in determining Z*. This shows that both local (μ\mu*-driven) and global (M*-driven) processes are important in determining the metallicity in galaxies. We find that the overall balance between local and global effects varies with the location within a galaxy. In disks, μ\mu* regulates Z*, producing a strong μ\muZR whose amplitude is modulated by M*. In spheroids it is M* who dominates the physics of star formation and chemical enrichment, with μ\mu* playing a minor, secondary role. These findings agree with our previous analysis of the star formation histories of CALIFA galaxies, which showed that mean stellar ages are mainly governed by surface density in galaxy disks and by total mass in spheroids.Comment: 6 pages, 3 figures, accepted for publication in ApJ
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