Heart Rate Extraction from Novel Neck Photoplethysmography Signals.

This paper demonstrates for the first time how heart rate (HR) can be extracted from novel neck photoplethysmography (PPG). A novel algorithm is presented, which when tested in neck PPG signals recorded from 9 subjects at different respiratory rates, obtained good precision with respect to gold standard ECG signals. Mean absolute error (MAE), standard deviation error (SDAE) and root-mean-square error (RMSE) resulted in 1.22, 1.54 and 1.98 beats per minute (BPM), respectively. HRneck estimation showed strong correlation (R=0.94) with reference HRECG. Good agreement between both techniques was also demonstrated by Bland-Altman analysis. The bias between mean HR paired differences was -0.16 BPM and 95% limits of agreement (LoA) were (-4.7, 4.4). Comparatively, for widely used finger PPG, errors were slightly smaller (MAE=0.38 BPM, SDAE=0.48 BPM, RMSE=0.62BPM) and the correlation with reference ECG was also very close to 1 (R=0.99). Bias of -0.04 BPM and 95% LoA (-1.5, 1.4), also showed high degree of agreement. However, these findings show the potential the neck could have as an alternative body location for wearable monitors, aiming to reduce the number of sensing sites whilst still providing access to a wide variety of physiological parameters

Extracting the jugular venous pulse from anterior neck contact photoplethysmography

The jugular venous pulse (JVP) is the reference physiological signal used to detect right atrial and central venous pressure (CVP) abnormalities in cardio-vascular diseases (CVDs) diagnosis. Invasive central venous line catheterization has always been the gold standard method to extract it reliably. However, due to all the risks it entails, novel non-invasive approaches, exploiting distance cameras and lasers, have recently arisen to measure the JVP at the external and internal jugular veins. These remote options however, constraint patients to very specific body positions in front of the imaging system, making it inadequate for long term monitoring. In this study, we demonstrate, for the first time, that reflectance photoplethysmography (PPG) can be an alternative for extracting the JVP from the anterior jugular veins, in a contact manner. Neck JVP-PPG signals were recorded from 20 healthy participants, together with reference ECG and arterial finger PPG signals for validation. B-mode ultrasound imaging of the internal jugular vein also proved the validity of the proposed method. The results show that is possible to identify the characteristic a, c, v pressure waves in the novel signals, and confirm their cardiac-cycle timings in consistency with established cardiac physiology. Wavelet coherence values (close to 1 and phase shifts of ±180°) corroborated that neck contact JVP-PPG pulses were negatively correlated with arterial finger PPG. Average JVP waveforms for each subject showed typical JVP pulses contours except for the singularity of an unknown "u" wave occurring after the c wave, in half of the cohort. This work is of great significance for the future of CVDs diagnosis, as it has the potential to reduce the risks associated with conventional catheterization and enable continuous non-invasive point-of-care monitoring of CVP, without restricting patients to limited postures

Phenomenology Tools on Cloud Infrastructures using OpenStack

We present a new environment for computations in particle physics phenomenology employing recent developments in cloud computing. On this environment users can create and manage "virtual" machines on which the phenomenology codes/tools can be deployed easily in an automated way. We analyze the performance of this environment based on "virtual" machines versus the utilization of "real" physical hardware. In this way we provide a qualitative result for the influence of the host operating system on the performance of a representative set of applications for phenomenology calculations.Comment: 25 pages, 12 figures; information on memory usage included, as well as minor modifications. Version to appear in EPJ

Essays in the evaluation of human capital investment policies

In this thesis dissertation, I study which factors drive human capital investments at different stages of the life-cycle by using structural dynamic behavioral models, and what we can learn from these models in order to design better labor and education policies in the long-term. Over the three chapters of this work I assess policy relevant questions that are either related to both developing and developed countries, and I show how these methodologies can be used in conjunction with other more traditional approaches to perform two types of policy evaluation: the assessment of existing policies, or ex-post policy evaluation, and the prediction of economic behavior under policies that have not been yet implemented, or ex-ante policy evaluation. My work has two main goals. The first goal is methodological. I show the gains of structural modeling in understanding the mechanisms behind human capital investments, for example the disentanglement of preferences, returns and expectations, and the importance of dynamics. I also show how these models can be complemented and even better identified when they are combined with experimental data. The second goal is to answer some relevant economic questions for which there are still no answers. On one hand, I study the determinants of labor informality and self-employment in developing countries disentangling the role of comparative advantage and labor market segmentation on labor informality. On another hand, I study the determinants of parental investments in children and their effects in child development, first emphasizing the role of parental income and financial constraints, and then focusing on less investigated factors like parental beliefs and attitudes towards child-rearing

Catalytic Conversion of Glucose and Chlorella sp. into Furans in the Presence of Niobium Oxide

A series of Nb2O5 solid catalysts have been prepared to be used for the catalytic dehydration of glucose and sugars from algae Chlorella sp. into added value furans. The glucose transformation gave rise to 5-hydroxymethylfurfural (5-HMF). Chlorella sp. was used in the same catalytic conditions to be valorised to furans. By preliminary studies we concluded that the algae aqueous suspension needed a previous treatment in the presence of SiO2 pellets to liberate the carbohydrates that in the catalytic reaction in the presence of Nb2O5 materials gave rise 5-HMF and furfural. The best operative conditions and Nb2O5 catalysts were individuated. The most performant Nb2O5 catalyst also showed an excellent reusability without deactivation. The selectivity to furans was related to the acidity of the solid used as catalyst

Un modelo basado en agentes para el análisis de la segregación étnica espacial urbana

Se pretende analizar la segregación étnica espacial urbana mediante un modelo basado en agentes. Con dicho propósito, se ha estudiado el efecto de variables como la densidad de la población, el nivel de intolerancia hacia grupos étnicos diferentes al propio, el grado de heterogeneidad cultural, el tamaño del vecindario y el tamaño de las minorías en la segregación étnica espacial urbana (medida a través del índice de disimilaridad). En particular, se han realizado una serie de experimentos virtuales con un modelo basado en agentes construido a partir del modelo de Schelling, pero con presupuestos sobre el comportamiento de los individuos más realistas. Los resultados de los experimentos virtuales podrían ayudar a diseñar políticas sociales dirigidas a reducir la segregación étnica espacial urbana en sociedades multiétnicas. This work attempts to analyse the urban spatial ethnic segregation through an agent-based model. For that purpose, it studies the effect of variables as the density of population, the level of intolerance towards different ethnic groups, the level of cultural diversity, the size of neighbourhood and the size of minorities on the urban spatial ethnic segregation (measured by the index of dissimilarity). In particular, it carries out virtual experiments with an agent-based model building from Schelling''s model, but with assumptions about the behaviour of individuals more realistic. The results of virtual experiments could help to design social policies in order to reduce the urban spatial ethnic segregation in multiethnic societies

On the origin of X-ray oxygen emission lines in obscured AGN

We present the Catalogue of High Resolution Spectra of Obscured Sources (CHRESOS) from the XMM-Newton Science Archive. It comprises the emission-line luminosities of H- and He-like transitions from C to Si, and the Fe 3C and Fe 3G L-shell ones. Here, we concentrate on the soft X-ray OVII (f) and OVIII Ly alpha emission lines to shed light on to the physical processes with which their formation can be related to active galactic nucleus (AGN) versus star-forming regions. We compare their luminosity with that of two other important oxygen key lines [O III]lambda 5007 angstrom, in the optical, and [O IV] 25.89 mu m, in the infrared (IR). We also test OVII (f) and OVIII Ly alpha luminosities against that of continuum bands in the IR and hard X-rays, which point to different ionization processes. We probe into those processes by analysing photoionization and collisional ionization model predictions upon our lines. We show that both scenarios can explain the formation and observed intensities of OVII (f) and OVIII Ly alpha. By analysing the relationships between OVII (f) and OVIII Ly alpha, and all other observables: [OIII]lambda 5007 angstrom, [O IV] 25.89 mu m emission lines, and mid-infrared (MIR) 12 mu m, far-infrared (FIR) 60 and 100 mu m, 2-10 and 14-195 keV continuum bands, we conclude that the AGN radiation field is mainly responsible of the soft X-ray oxygen excitation

Photocatalytic CO 2 Valorization by Using Ti O2 , ZrO2 and Graphitic Based Semiconductors

In this century, a broad scientific interest has been devoted to fulfill sustainable industrial processes and climatic change remediation. In this prospective, various green technologies have been studied to valorize CO 2• The aim of this research is the CO 2 reduction in presence of water by using the photocatalytic technology with nanomaterials as the photocatalysts. The present work overviews the main outcomes obtained by using graphitic and oxide based photocatalysts both in gas/solid and liquid/solid batch reactors under simulated solar light. In all gas/solid regime tests the major products detected were methane, carbon monoxide, and acetaldehyde