An exact goodness-of-fit test based on the occupancy problems to study zero-inflation and zero-deflation in biological dosimetry data

The goal in biological dosimetry is to estimate the dose of radiation that a suspected irradiated individual has received. For that, the analysis of aberrations (most commonly dicentric chromosome aberrations) in scored cells is performed and dose response calibration curves are built. In whole body irradiation (WBI) with X- and gamma-rays, the number of aberrations in samples is properly described by the Poisson distribution, although in partial body irradiation (PBI) the excess of zeros provided by the non-irradiated cells leads, for instance, to the Zero-Inflated Poisson distribution. Different methods are used to analyse the dosimetry data taking into account the distribution of the sample. In order to test the Poisson distribution against the Zero-Inflated Poisson distribution, several asymptotic and exact methods have been proposed which are focused on the dispersion of the data. In this work, we suggest an exact test for the Poisson distribution focused on the zero-inflation of the data developed by Rao and Chakravarti (Some small sample tests of significance for a Poisson distribution. Biometrics 1956;12 : 264–82.), derived from the problems of occupancy. An approximation based on the standard Normal distribution is proposed in those cases where the computation of the exact test can be tedious. A Monte Carlo Simulation study was performed in order to estimate empirical confidence levels and powers of the exact test and other tests proposed in the literature. Different examples of applications based on in vitro data and also data recorded in several radiation accidents are presented and discussed. A Shiny application which computes the exact test and other interesting goodness-of-fit tests for the Poisson distribution is presented in order to provide them to all interested researchers

Analytical modelling of high concentrator photovoltaic modules based on atmospheric parameters

PublishedJournal Article© 2015 Eduardo F. Fernández et al. The goal of this paper is to introduce a model to predict the maximum power of a high concentrator photovoltaic module. The model is based on simple mathematical expressions and atmospheric parameters. The maximum power of a HCPV module is estimated as a function of direct normal irradiance, cell temperature, and two spectral corrections based on air mass and aerosol optical depth. In order to check the quality of the model, a HCPV module was measured during one year at a wide range of operating conditions. The new proposed model shows an adequate match between actual and estimated data with a root mean square error (RMSE) of 2.67%, a mean absolute error (MAE) of 4.23 W, a mean bias error (MBE) of around 0%, and a determination coefficient (R 2) of 0.99.Partial funding for this study was provided through EPSRC funded BioCPV (EP/J000345/1) project. Also, this work is part of the project “Desenvolvemento de novos conceptos baseados en tecnoloxía de concentración fotovoltaica para a produción de enerxía eléctrica adaptados a distintas zonas climáticas,” through the program “Formación Posdoutoral do Plan Galego de Investigación, Innovación e Crecemento 2011–2015 (Plan I2C)” funded by the Xunta de Galicia and by the European Social Fund

Optical modeling of four Fresnel-based high-CPV units

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordHigh Concentrator Photovoltaic (HCPV) units are typically based on the use of Fresnel lenses, refractive secondary optical elements (SOE), and triple-junction (TJ) solar cells. In this work, a detailed optical modeling is applied to analyze the performance of four Fresnel-based HCPV units equipped with different refractive SOEs while considering the subcells current density generation. Wavelength-dependent material properties are utilized while simulating the optical performance. The spectral response of a typical TJ solar cell is also included. This modeling allows to establish the subcell current limitation and the spectral matching ratio, SMR, values in each case. The following SOEs have been used for simulating the HCPV units: (i) Dielectric-cross compound-parabolic-concentrator (DCCPC), (ii) (SIngle-Lens-Optical element) SILO-Pyramid, (iii) Refractive truncated pyramid (RTP) and, (iv) Trumpet. Results show that the HCPV units with SOEs RTP and Trumpet, exhibit bottom subcell current limitation and lowest optical polychromatic efficiency, this is partly due to the irradiance absorption in the bottom cell spectral region and longer optical path length of the concentrated rays within the SOE material. In the case of the HCPV unit with the DCCPC SOE, top and bottom subcells limit the current generation alternatively depending on the misalignment angle of the HCPV unit respect to the simulated sunrays. None of the SMR parameters are equal to 1 under normal alignment of the HCPV units. The short-circuit current density distributions for each subcell in each case are studied under normal alignment and under 1° of misalignment angle.European Regional Development Fund (ERDF) and Spanish Economy Ministry (ENE2013-45242-R and ENE2016-78251-R); Universidad de Jaén (UJA) and Caja Rural de Jaén (UJA2015/07/01). Financial support provided by the Universidad de Jaén Doctoral School

Analysis of high concentrator photovoltaic modules in outdoor conditions: Influence of direct normal irradiance, air temperature, and air mass

The study of high concentrator photovoltaic (HCPV) technology under real conditions is essential to understand its real behavior. The influence of direct normal irradiance (DNI), air temperature (Tair), and air mass (AM) on the maximum power of two HCPV modules was studied for more than three years. Results found are presented in this paper. As expected, the main influence on the maximum power is DNI. Also, Tair has been found to have small influence on the maximum power. Regarding AM, two different behaviors have been found. The maximum power could be considered independent of AM for AM 2, while it decreases with an approximate linear behavior for AM > 2. Also, the maximum power of a HCPV module could be estimated with a linear mathematical fitting based on DNI, Tair, and AMThis work is a part of the project “SIGMPLANTAS: La innovacion en las plantas y modelos de sistemas de Concentracion Fotovoltaica en España,” IPT-2011-1468-920000 supported by the Spanish Science and Innovation Ministry and by the European Regional Development Fund/Fondo Europeo de Desarrollo Regional (ERDF/FEDER)S

A healthy lifestyle attenuates the effect of polypharmacy on total and cardiovascular mortality: a national prospective cohort study

This work examines whether the increased all-cause and cardiovascular disease (CVD) mortality associated with polypharmacy could be offset by a healthy lifestyle. We included a prospective cohort of 3,925 individuals representative of the Spanish population aged ≥60 years, who were recruited in 2000–2001 and followed up through 2014. Polypharmacy was defined as treatment with ≥5 medications. The following lifestyle behaviors were considered healthy: not smoking, eating a healthy diet, being physically active, moderate alcohol consumption, low sitting time, and adequate sleep duration. Individuals were classified into three lifestyle categories s: unfavorable (0–2), intermediate (3–4) favorable (5–6). Over a median 13.8-y follow-up, 1,822 all-cause and 675 CVD deaths occurred. Among individuals with polypharmacy, intermediate and favorable lifestyles were associated with an all-cause mortality reduction (95% confidence interval [CI]) of 47% (34–58%) and 54% (37–66%), respectively; 37% (9–56%) and 60% (33–76%) for CVD death, respectively. The theoretical adjusted hazard ratio (95%CI) associated with replacing 1 medication with 1 healthy lifestyle behavior was 0.73 (0.66–0.81) for all-cause death and 0.69 (0.59–0.82) for CVD death. The theoretical adjusted hazard ratio (95%CI) for all-cause and CVD mortality associated with simply reducing 1 medication was 0.88 (0.83–0.94) and 0.83 (0.76–0.91), respectively. Hence, adherence to a healthy lifestyle behavior can reduce mortality risk associated with polypharmacy in older adults.This work was supported by FIS grants 16/609 and 13/0288 (Instituto de Salud Carlos III, State Secretary of R + D + I and FEDER/FSE), MINECO R + D + I grant (DEP2013-47786-R), the FRAILOMIC Initiative (European Union FP7-HEALTH-2012-Proposal No. 305483-2), and the ATHLOS project (European project H2020- Project ID:635316

Design and characterization of refractive secondary optical elements for a point-focus Fresnel lens-based high CPV system

This is the final version of the article. Available from AIP Publishing via the DOI in this record.Point-focus Fresnel lens-based High Concentrator Photovoltaic (HCPV) systems are usually equipped with refractive secondary optical elements (SOE) in order to improve their performance. Two basic SOE designs are optically modeled and simulated in this work: Domed-Kaleidoscope (D-K) with breaking-symmetry top and SILO (SIngle-Lens-Optical element). Wavelength-dependent optical material properties like refractive index and absorption coefficient, as well as the spectral response of a typical triple-junction (TJ) solar cell, are included in the ray tracing simulations. Moreover, using a CPV Solar Simulator "Helios 3198", both HCPV units are experimentally characterized. The acceptance angle characteristics of both HCPV units, obtained through optical simulations and through indoor characterization, are compared. The acceptance angle characteristic is better for the HCPV unit with the D-K SOE both in simulations and in experimental measurements, showing concordance between simulation and experiment. However, simulation results underestimate the experimental ones concerning the acceptance angle, which will be investigated in future works.European Regional Development Fund (ERDF) and Spanish Economy Ministry (ENE2013-45242-R and ENE2016-78251-R); Universidad de Jaén (UJA) and Caja Rural de Jaén (UJA2015/07/01). Financial support provided by the Universidad de Jaén Doctoral School. The authors also thank Lambda Research Corporation for its donation of TracePro optical software

Entrenamiento de las señales corticales a través de un sistema BMI-EEG, evolución e intervención. A propósito de un caso = Training cortical signals by means of a BMI-EEG system, its evolution and intervention. A case report

INTRODUCTION: In the last years, new technologies such as the brain-machine interfaces (BMI) have been incorporated in the rehabilitation process of subjects with stroke. These systems are able to detect motion intention, analyzing the cortical signals using different techniques such as the electroencephalography (EEG). This information could guide different interfaces such as robotic devices, electrical stimulation or virtual reality. CASE REPORT: A 40 years-old man with stroke with two months from the injury participated in this study. We used a BMI based on EEG. The subject's motion intention was analyzed calculating the event-related desynchronization. The upper limb motor function was evaluated with the Fugl-Meyer Assessment and the participant's satisfaction was evaluated using the QUEST 2.0. The intervention using a physical therapist as an interface was carried out without difficulty. CONCLUSIONS: The BMI systems detect cortical changes in a subacute stroke subject. These changes are coherent with the evolution observed using the Fugl-Meyer Assessment

Clinical and Ambulatory Gait Speed in Older Adults: Associations With Several Physical, Mental, and Cognitive Health Outcomes

Background: Although clinical gait speed may indicate health and well-being in older adults, there is a lack of studies comparing clinical tests with ambulatory gait speed with regard to several health outcomes. Objective: The objective of this study was to examine the associations of clinical gait speed, measured by the 2.44-m walk test and the ambulatory gait speed with several physical, mental, and cognitive health outcomes in older adults. Design: A cross-sectional design was used. Methods: The study population comprised 432 high-functioning, community-dwelling older adults (287 women) aged between 65 and 92 years. Clinical and ambulatory gait speeds were measured using the 2.44-m walk test and a portable gait analysis device, respectively. Multiple linear regressions were used to examine the association of clinical and ambulatory gait speeds with several health outcomes (body mass index, waist circumference, systolic and diastolic blood pressure, chronic conditions, self-rated health, exhaustion, upper- and lower-body strength, physical and mental health status, cognitive status, and self-rated cognitive status). Results: The results showed that the average gait speed for clinical and ambulatory measures cannot be directly compared. Clinical gait speed was associated with 7 health outcomes, and the ambulatory gait speed was associated with 6 health outcomes. The significant associations between measures of gait speed and the health outcomes converged in 5 of the 13 health outcomes studied; however, the strength of associations was singly different between measures. Limitations: The short monitoring time, the inability to distinguish between the ambulatory gait speed inside the home and outdoor gait speed, and the under-representative sample are limitations of the study. Conclusion: The results indicated differences in the number and strength of associations between clinical and ambulatory gait speed. Both measures have construct validity because they have been associated with physical and health outcomes; however, they may have different predictive validity. Further research should be conducted to compare their predictive validity in longitudinal design