435 research outputs found
Fluctuating ecological networks: A synthesis of maximum‐entropy approaches for pattern detection and process inference
Linking Through Time: Memory-Enhanced Community Discovery in Temporal Networks
Temporal Networks, and more specifically, Markovian Temporal Networks,
present a unique challenge regarding the community discovery task. The inherent
dynamism of these systems requires an intricate understanding of memory effects
and structural heterogeneity, which are often key drivers of network evolution.
In this study, we address these aspects by introducing an innovative approach
to community detection, centered around a novel modularity function. We focus
on demonstrating the improvements our new approach brings to a fundamental
aspect of community detection: the detectability threshold problem. We show
that by associating memory directly with nodes' memberships and considering it
in the expression of the modularity, the detectability threshold can be lowered
with respect to cases where memory is not considered, thereby enhancing the
quality of the communities discovered. To validate our approach, we carry out
extensive numerical simulations, assessing the effectiveness of our method in a
controlled setting. Furthermore, we apply our method to real-world data to
underscore its practicality and robustness. This application not only
demonstrates the method's effectiveness but also reveals its capacity to
indirectly tackle additional challenges, such as determining the optimal time
window for aggregating data in dynamic graphs. This illustrates the method's
versatility in addressing complex aspects of temporal network analysis
DC Charging Station for Electric and Plug-in Vehicles
AbstractThis paper is focused on the evaluation of theoretical and experimental aspects related to the different operation modes of a laboratory power architecture, which realizes a micro grid for the charging of road electric and plug-in hybrid vehicles. The analyzed power configuration is based on a DC bus architecture, which presents the main advantage of an easy integration of renewable energy sources and buffered storage systems. A first phase of simulations is aimed to evaluate the main energy fluxes within the studied architecture and to identify the energy management strategies, which optimize simultaneously the power requirements from the main grid and charging times of different electric vehicles. A second phase is based on the experimental characterization of the analyzed power architecture, implementing the control strategies evaluated in the simulation environment, through a laboratory acquisition and control system. Then the experimental results coming from the laboratory prototype are compared with the simulation results, in order to achieve a better parameter setting of the simulation model for the analyzed structure. This preliminary analysis makes possible other simulations to be carried out on more complex architecture of micro-grids, taking into account the integration of renewable energy sources and high power buffer storage systems. Particular attention is also given to the analysis of ultra-fast charging operations and the related performance in terms of total efficiency, charging times, total power factor and power requirements from the main grid. This study represents a further step toward the new concept of smart grid scenario for electric vehicles
The Elasticity of Substitution in Demand for Non-Tradable Goods in Latin America: The Case of Argentina
The objective of this paper is to estimate the elasticity of substitution in the demand for non-tradable goods relative to tradable goods in Argentina. This parameter plays a crucial role in the analysis of the macroeconomic equilibrium of a small open economy (Mendoza, Galindo and Izquierdo, 2003). Using two data sets, estimates of approximately 0. 40 and 0. 48, respectively, are found for this elasticity.
Temporal networks with node-specific memory: unbiased inference of transition probabilities, relaxation times and structural breaks
One of the main challenges in the study of time-varying networks is the
interplay of memory effects with structural heterogeneity. In particular,
different nodes and dyads can have very different statistical properties in
terms of both link formation and link persistence, leading to a superposition
of typical timescales, sub-optimal parametrizations and substantial estimation
biases. Here we develop an unbiased maximum-entropy framework to study
empirical network trajectories by controlling for the observed structural
heterogeneity and local link persistence simultaneously. An exact mapping to a
heterogeneous version of the one-dimensional Ising model leads to an analytic
solution that rigorously disentangles the hidden variables that jointly
determine both static and temporal properties. Additionally, model selection
via likelihood maximization identifies the most parsimonious structural level
(either global, node-specific or dyadic) accounting for memory effects. As we
illustrate on a real-world social network, this method enables an improved
estimation of dyadic transition probabilities, relaxation times and structural
breaks between dynamical regimes. In the resulting picture, the graph follows a
generalized configuration model with given degrees and given time-persisting
degrees, undergoing transitions between empirically identifiable stationary
regimes
Impacto de la intervención enfermera en la calidad de vida del cuidador del paciente con enfermedad de Alzheimer Revisión integradora
Treball Final de Grau en Infermeria. Codi: IN1138. Curs: 2021/2022Introducción: La enfermedad de Alzheimer (EA) es un trastorno caracterizado por un
deterioro cognitivo que afecta a la memoria, el pensamiento y el comportamiento,
causando una dependencia y unas necesidades elevadas en las actividades básicas de la
vida diaria. Los cuidadores de estos pacientes sufren sobrecarga y su calidad de vida se
ve afectada a causa de la atención que requieren.
Objetivo: Conocer y exponer las estrategias e intervenciones que mejoran la calidad de
vida de los cuidadores de los pacientes con EA.
Métodos: Se realizó una revisión integradora de la literatura acerca de las intervenciones
enfermeras sobre la calidad de vida de los cuidadores de pacientes con EA. Esta se realizó
en bases de datos mediante los descriptores de ciencias de la salud y los medical subject
headings. Se tuvieron en cuenta unos criterios de inclusión y exclusión y se realizó una
evaluación de la calidad metodológica de los estudios seleccionados.
Resultados: Se escogieron para la revisión 9 estudios científicos. En estos, se observaron
la cantidad de intervenciones que enfermería podía aportar a la mejora de la calidad de
vida de los cuidadores. Entre estas intervenciones se encuentran: educación para la salud,
apoyo físico y psicológico, disponibilidad de recursos sociosanitarios o intervenciones
como las multicomponentes o psicoterapéuticas.
Conclusión: Enfermería tiene un importante papel en el cuidado de este tipo de personas.
A pesar de la falta de investigación, muchas intervenciones dan resultados beneficiosos y
que aumentan la calidad de vida de los cuidadores.Introduction: Alzheimer's disease (AD) is a disorder characterised by cognitive
impairment affecting memory, thinking and behaviour, causing dependency and high
needs in basic activities of daily living. Carers of these patients are overburdened and
their quality of life is affected by the care they require.
Objective: To know and present the strategies and interventions that improve the quality
of life of caregivers of AD patients.
Methods: An integrative review of the literature on nursing interventions on the quality
of life of caregivers of patients with AD was carried out. This was carried out in databases
using health science descriptors and medical subject headings. Inclusion and exclusion
criteria were taken into account and the methodological quality of the selected studies
was assessed.
Results: Nine scientific studies were chosen for the review. In these, we observed the
number of interventions that nursing could contribute to improving the quality of life of
caregivers. These interventions included health education, physical and psychological
support, availability of socio-health resources or interventions such as multicomponent
or psychotherapeutic interventions.
Conclusions: Nursing has an important role in the care of such people. Despite the lack
of research, many interventions have beneficial and life-enhancing outcomes for carers
Noticias preliminares sobre los materiales del yacimiento de Papauvas (Aljaraque, Huelva)
The SSSA-MyHand: a dexterous lightweight myoelectric hand prosthesis
The replacement of a missing hand by a prosthesis is one of the most fascinating challenges in rehabilitation engineering. State of art prostheses are curtailed by the physical features of the hand, like poor functionality and excessive weight. Here we present a new multi-grasp hand aimed at overcoming such limitations. The SSSA-MyHand builds around a novel transmission mechanism that implements a semi-independent actuation of the abduction/adduction of the thumb and of the flexion/extension of the index, by means of a single actuator. Thus, with only three electric motors the hand is capable to perform most of the grasps and gestures useful in activities of daily living, akin commercial prostheses with up to six actuators, albeit it is as lightweight as conventional 1-Degrees of Freedom prostheses. The hand integrates position and force sensors and an embedded controller that implements automatic grasps and allows inter-operability with different human-machine interfaces. We present the requirements, the design rationale of the first prototype and the evaluation of its performance. The weight (478 g), force (31 N maximum force at the thumb fingertip) and speed of the hand (closing time: <370 ms), make this new design an interesting alternative to clinically available multi-grasp prostheses
FGF-2 and anosmin-1 are selectively expressed in different types of multiple sclerosis lesions
Multiple sclerosis is a demyelinating disease that affects ~2,000,000 people worldwide. In the advanced stages of the disease, endogenous oligodendrocyte precursors cannot colonize the lesions or differentiate into myelinating oligodendrocytes. During development, both FGF-2 and Anosmin-1 participate in oligodendrocyte precursor cell migration, acting via the FGF receptor 1 (FGFR1). Hence, we performed a histopathological and molecular analysis of these developmental modulators in postmortem tissue blocks from multiple sclerosis patients. Accordingly, we demonstrate that the distribution of FGF-2 and Anosmin-1 varies between the different types of multiple sclerosis lesions: FGF-2 is expressed only within active lesions and in the periplaque of chronic lesions, whereas Anosmin-1 is upregulated within chronic lesions and is totally absent in active lesions. We show that the endogenous oligodendrocyte precursor cells recruited toward chronic-active lesions express FGFR1, possibly in response to the FGF-2 produced by microglial cells in the periplaque. Also in human tissue, FGF-2 is upregulated in perivascular astrocytes in regions of the normal-appearing gray matter, where the integrity of the blood-brain barrier is compromised. In culture, FGF-2 and Anosmin-1 influence adult mouse oligodendrocyte precursor cell migration in the same manner as at embryonic stages, providing an explanation for the histopathological observations: FGF-2 attracts/ enhances its migration, which is hindered by Anosmin-1. We propose that FGF-2 and Anosmin-1 are markers for the histopathological type and the level of inflammation of multiple sclerosis lesions, and that they may serve as novel pharmacogenetic targets to design future therapies that favor effective remyelination and protect the blood-brain barrier. © 2011 the authors.Peer Reviewe
Propuesta de estrategias mitigación de la huella de carbono de los procesos de la empresa Konecta BTO SL, sucursal en Perú, sede Lima cargo, durante el 2019
El presente trabajo de investigación se realizó en la empresa Konecta BTO SL Sucursal en Perú, dedicada a brindar el servicio outsourcing en la atención al cliente a través de llamadas diversos tipos de empresas en Perú y otros países. El objetivo fue proponer estrategias de mitigación de huella de carbono de los procesos de la organización. Para llevar a cabo el trabajo de investigación se tuvo como referencia las directrices del IPCC para inventarios de gases de efecto invernadero y la norma ISO 14064-1:2006. Se determinó que la sede Lima Cargo durante el 2019 tuvo una cuantificación total de emisiones 828.71 tCO2eq, que está compuesto por el alcance 1 de emisiones directas de GEI que contribuye el 9%, alcance 2 de emisiones indirectas de GEI por energía que aporta el 24%, alcance 3 otras emisiones indirectas de GEI que contribuye el 38% y otros gases que no son GEI (HCFC) que aportan el 28%. Se obtuvo un nivel de incertidumbre bajo para la cuantificación de la mayoría de fuentes de emisión, lo cual detalla que los resultados de la cuantificación son fiables. Finalmente, se propusieron 3 estrategias de mitigación para la huella de carbono: no programar vehículos que consuman gasolina y GLP para el transporte terrestre, cambiar los gases refrigerantes R-22 y R-410 A por el gas refrigerante R-32 en sistema de aire acondicionado, renovar todo el conjunto de CPU por un modelo que cuente alimentación energética de 65 watt cuentan una proyección de reducción de emisiones de 2.31%; 22.80%; 6.76% respectivamente.The present research work was carried out in the company Konecta BTO SL Branch in Peru, dedicated to provide outsourcing services in customer service through calls to various types of companies in Peru and other countries. The objective was to propose carbon footprint mitigation strategies for the organization's processes. The IPCC guidelines for greenhouse gas inventories and the ISO 14064-1:2006 standard were used as a reference for the research work. It was determined that the Lima Cargo headquarters during 2019 had a total quantification of emissions 828.71 tCO2eq, which is composed of scope 1 direct GHG emissions contributing 9%, scope 2 indirect GHG emissions from energy contributing 24%, scope 3 other indirect GHG emissions contributing 38% and other non-GHG gases (HCFC) contributing 28%. A low level of uncertainty was obtained for the quantification of most emission sources, which indicates that the quantification results are reliable. Finally, 3 mitigation strategies for the carbon footprint were proposed: not to program vehicles that consume gasoline and LPG for ground transportation, to change the refrigerant gases R-22 and R-410 A for the refrigerant gas R-32 in the air conditioning system, to renew the whole set of CPUs for a model that has an energy supply of 65 watts with a projected reduction of emissions of 2.31%; 22.80%; 6.76% respectively
- …