709 research outputs found

    Sources of uncertainty in annual global horizontal irradiance data

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    The major sources of uncertainty in short-term assessment of global horizontal radiation (G) are the pyranometer type and their operation conditions for measurements, whereas the modeling approach and the geographic location are critical for estimations. The influence of all these factors in the uncertainty of the data has rarely been compared. Conversely, solar radiation data users are increasingly demanding more accurate uncertainty estimations. Here we compare the annual bias and uncertainty of all the mentioned factors using 732 weather stations located in Spain, two satellite-based products and three reanalyses. The largest uncertainties were associated to operational errors such as shading (bias = - 8.0%) or soiling (bias = - 9.4%), which occurred frequently in low-quality monitoring networks but are rarely detected because they pass conventional QC tests. Uncertainty in estimations greatly changed from reanalysis to satellite-based products, ranging from the gross accuracy of ERA-Interim (+ 6.1(-6.7)(+)(1)(8.)(8)%) to the high quality and spatial homogeneity of SARAH-1 (+ 1.4(-5.3)(+)(5.6)%). Finally, photodiodes from the Spanish agricultural network SIAR showed an uncertainty of (+6.)(9)(-5.4)%, which is far greater than that of secondary standards (+/- 1.5%) and similar to SARAH-1. This is probably caused by the presence of undetectable operational errors and the use of uncorrected photodiodes. Photodiode measurements from low-quality monitoring networks such as SIAR should be used with caution, because the chances of adding extra uncertainties due to poor maintenance or inadequate calibration considerably increase.Peer reviewe

    Omic Technologies in HIV: Searching Transcriptional Signatures Involved in Long-Term Non-Progressor and HIV Controller Phenotypes

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    RevisiónThis article reviews the main discoveries achieved by transcriptomic approaches on HIV controller (HIC) and long-term non-progressor (LTNP) individuals, who are able to suppress HIV replication and maintain high CD4+ T cell levels, respectively, in the absence of antiretroviral therapy. Different studies using high throughput techniques have elucidated multifactorial causes implied in natural control of HIV infection. Genes related to IFN response, calcium metabolism, ribosome biogenesis, among others, are commonly differentially expressed in LTNP/HIC individuals. Additionally, pathways related with activation, survival, proliferation, apoptosis and inflammation, can be deregulated in these individuals. Likewise, recent transcriptomic studies include high-throughput sequencing in specific immune cell subpopulations, finding additional gene expression patterns associated to viral control and/or non-progression in immune cell subsets. Herein, we provide an overview of the main differentially expressed genes and biological routes commonly observed on immune cells involved in HIV infection from HIC and LTNP individuals, analyzing also different technical aspects that could affect the data analysis and the future perspectives and gaps to be addressed in this field.This study was funded by a fellowship from GILEAD Sciences (GLD18/00090), Instituto de Salud Carlos III (PI19CIII/00004), and has been conducted within the Spanish AIDS Research Network (RIS), funded by Instituto de Salud Carlos III (Plan Estatal de I+D+I 2013-2016) and co-funded by European Regional Development Fund (ERDF) "A way to build Europe" (RD16CIII/0002/0001). RA-S was supported by the Ministry of Innovation, Science and Universities predoctoral funding (FPU18/05527)S

    Analysis of Spanish Radiometric Networks with the Novel Bias-Based Quality Control (BQC) Method

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    Different types of measuring errors can increase the uncertainty of solar radiation measurements, but most common quality control (QC) methods do not detect frequent defects such as shading or calibration errors due to their low magnitude. We recently presented a new procedure, the Bias-based Quality Control (BQC), that detects low-magnitude defects by analyzing the stability of the deviations between several independent radiation databases and measurements. In this study, we extend the validation of the BQC by analyzing the quality of all publicly available Spanish radiometric networks measuring global horizontal irradiance (9 networks, 732 stations). Similarly to our previous validation, the BQC found many defects such as shading, soiling, or calibration issues not detected by classical QC methods. The results questioned the quality of SIAR, Euskalmet, MeteoGalica, and SOS Rioja, as all of them presented defects in more than 40% of their stations. Those studies based on these networks should be interpreted cautiously. In contrast, the number of defects was below a 5% in BSRN, AEMET, MeteoNavarra, Meteocat, and SIAR Rioja, though the presence of defects in networks such as AEMET highlights the importance of QC even when using a priori reliable stations.Peer reviewe

    Evaluation of global horizontal irradiance estimates from ERA5 and COSMO-REA6 reanalyses using ground and satellite-based data

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    This study examines the progress made by two new reanalyses in the estimation of surface irradiance: ERAS, the new global reanalysis from the ECMWF, and COSMO-REA6, the regional reanalysis from the DWD for Europe. Daily global horizontal irradiance data were evaluated with 41 BSRN stations worldwide, 294 stations in Europe, and two satellite-derived products (NSRDB and SARAH). ERAS achieves a moderate positive bias worldwide and in Europe of + 4.05 W/m 2 and + 4.54 W/m 2 respectively, which entails a reduction in the average bias ranging from 50% to 75% compared to ERA-Interim and MERRA-2. This makes ERAS comparable with satellite-derived products in terms of the mean bias in most inland stations, but ERAS results degrade in coastal areas and mountains. The bias of ERAS varies with the cloudiness, overestimating under cloudy conditions and slightly underestimating under clear-skies, which suggests a poor prediction of cloud patterns and leads to larger absolute errors than that of satellite-based products. In Europe, the regional COSMO-REA6 underestimates in most stations (MBE = -5.29 W/m(2)) showing the largest deviations under clear-sky conditions, which is most likely caused by the aerosol climatology used. Above 45 degrees N the magnitude of the bias and absolute error of COSMO-REA6 are similar to ERAS while it outperforms ERA5 in the coastal areas due to its high-resolution grid (6.2 km). We conclude that ERAS and COSMO-REA6 have reduced the gap between reanalysis and satellite-based data, but further development is required in the prediction of clouds while the spatial grid of ERAS (31 km) remains inadequate for places with high variability of surface irradiance (coasts and mountains). Satellite-based data should be still used when available, but having in mind their limitations, ERAS is a valid alternative for situations in which satellite-based data are missing (polar regions and gaps in times series) while COSMO-REA6 complements ERA5 in Central and Northern Europe mitigating the limitations of ERA5 in coastal areas.Peer reviewe

    Quantifying the amplified bias of PV system simulations due to uncertainties in solar radiation estimates

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    Solar radiation databases used for simulating PV systems are typically selected according to their annual bias in global horizontal irradiance (G(H)) because this bias propagates proportionally to plane-of-array irradiance (G(POA)) and module power (P-DC). However, the bias may get amplified through the simulations due to the impact of deviations in estimated irradiance on parts of the modeling chain depending on irradiance. This study quantifies these effects at 39 European locations by comparing simulations using satellite-based (SARAH) and reanalysis (COSMO-REA6 and ERAS) databases against simulations using station measurements. SARAH showed a stable bias through the simulations producing the best Pp c predictions in Central and South Europe, whereas the bias of reanalyses got substantially amplified because their deviations vary with atmospheric transmissivity due to an incorrect prediction of clouds. However, SARAH worsened at the northern locations covered by the product (55-65 degrees N) underestimating both G(POA) and P-DC. On the contrary, ERAS not only covers latitudes above 65 degrees but it also obtained the least biased P-DC estimations between 55 and 65 degrees N, which supports its use as a complement of satellite-based databases in high latitudes. The most significant amplifications occurred through the transposition model ranging from +/- 1% up to +/- 6%. Their magnitude increased linearly with the inclination angle, and they are related to the incorrect estimation of beam and diffuse irradiance. The bias increased around + 1% in the PV module model because the PV conversion efficiency depends on irradiance directly, and indirectly via module temperature. The amplification of the bias was similar and occasionally greater than the bias in annual G(H), so databases with the smallest bias in G(H) may not always provide the least biased PV simulations.Peer reviewe

    Relacionamento de preços no mercado nordestino de tomate

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    The objective this paper is to analyze the relationships in the prices on the tomatoes wholesale market prices of Fortaleza (CE), Ibiapaba (CE), Recife (PE) e Salvador (BA). Time series methods were used: unit root test, Johansen co-integration test, VAR models, and variance decomposition of prediction error and impulse response function. The results showed that the prices of Fortaleza influencies the wholesale market of Ibiapaba (CE), Recife (PE) e Salvador (BA).Wholesale market, Price transmission, VAR model, Tomatoes, Demand and Price Analysis,

    Cáncer de mama y ejercicio físico: Estudio piloto

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    El cáncer de mama (CM) es el más común entre las mujeres occidentales, con un alto porcentaje de supervivencia, la cual no está exenta de numerosos efectos secundarios tanto por los tratamientos como por la enfermedad, afectando a la calidad de vida de estas mujeres. El objetivo de este proyecto es conocer el efecto de un programa de ejercicio físico conducido en la calidad de vida de mujeres afectadas por cáncer de mama. Método. El programa de ejercicio físico consistió en 24 sesiones (doce semanas) y se desarrolló íntegramente en la Facultad de Ciencias de la Actividad Física y del Deporte-INEF (UPM), donde se estudió a 31 mujeres afectadas. Resultados. Se muestra una mejora en la calidad de vida (p= 0,034), así como en diferentes aspectos de autoestima y depresión (p = 0,029 y p = 0,003 para el primero y p = 0,018 y p = 0,015 para el segundo). También se observó una mejora en el índice de fuerza general (p = 0,009) y en la capacidad funcional (p = 0,005). Conclusiones. Estos resultados permiten asociar un programa de ejercicio físico regular con posibles mejoras en la calidad de vida de las mujeres afectadas por cáncer de mama

    Portable detection of apnea and hypopnea events using bio-impedance of the chest and deep learning

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    Sleep apnea is one of the most common sleep-related breathing disorders. It is diagnosed through an overnight sleep study in a specialized sleep clinic. This setup is expensive and the number of beds and staff are limited, leading to a long waiting time. To enable more patients to be tested, and repeated monitoring for diagnosed patients, portable sleep monitoring devices are being developed. These devices automatically detect sleep apnea events in one or more respiration-related signals. There are multiple methods to measure respiration, with varying levels of signal quality and comfort for the patient. In this study, the potential of using the bio-impedance (bioZ) of the chest as a respiratory surrogate is analyzed. A novel portable device is presented, combined with a two-phase Long Short-Term Memory (LSTM) deep learning algorithm for automated event detection. The setup is benchmarked using simultaneous recordings of the device and the traditional polysomnography in 25 patients. The results demonstrate that using only the bioZ, an area under the precision-recall curve of 46.9% can be achieved, which is on par with automatic scoring using a polysomnography respiration channel. The sensitivity, specificity and accuracy are 58.4%, 76.2% and 72.8% respectively. This confirms the potential of using the bioZ device and deep learning algorithm for automatically detecting sleep respiration events during the night, in a portable and comfortable setup

    IMPACTO DO ARTESANATO NA QUALIDADE DE VIDA DA COMUNIDADE DE PORTO DOS BARCOS, MUNICÍPIO DE ITAREMA, ESTADO DO CEARÁ

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    O objetivo deste artigo é analisar o impacto do artesanato na qualidade de vida da comunidade de Porto dos Barcos, do município de Itarema, Estado do Ceará. Para isso, foi construído um Índice de Qualidade de Vida, utilizando uma metodologia sugerida por Khan (2000), com o objetivo de verificar o nível de qualidade de vida nas comunidades estudadas. Os resultados mostraram que, após a implantação de um projeto de artesanato na comunidade de Porto dos Barcos, as famílias desta comunidade, passaram a ter uma melhor qualidade de vida. A comunidade controle (Barra do Farol), ainda possui uma qualidade de vida melhor que a de Porto dos Barcos, mas o crescimento da qualidade de vida de Porto dos Barcos foi consideravelmente melhor.-----------The objective of this paper is to analyze the impact of handicraft in quality of life of Porto dos Barcos community, in Itarema County, Ceará State, Brazil. Therefore, was built an Index of Quality of Live, using a methodology suggested by Khan (2000), with the objective of verifying the level of quality of life on the county studied. The results showed that, after the handicraft implantation of Porto dos Barcos community, the families of this community, started to have a better quality of life. The control community (Barra do Farol), still have a better quality of life than Porto dos Barcos, but the growth of quality of life of Porto dos Barcos was considerably.Artesanato, Qualidade de vida, Município de Itarema, Handicraft, Quality of Life, Itarema County, Community/Rural/Urban Development,

    Comparación de estrategias de laminación en embalses hidroeléctricos

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    En el artículo se presenta un entorno sistemático que facilita la comparación de las estrategias de laminación, evaluando su comportamiento general para un conjunto amplio de solicitaciones hidrológicas
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