2,799 research outputs found

    Video pulse rate variability analysis in stationary and motion conditions

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    Background: In the last few years, some studies have measured heart rate (HR) or heart rate variability (HRV) parameters using a video camera. This technique focuses on the measurement of the small changes in skin colour caused by blood perfusion. To date, most of these works have obtained HRV parameters in stationary conditions, and there are practically no studies that obtain these parameters in motion scenarios and by conducting an in-depth statistical analysis. Methods: In this study, a video pulse rate variability (PRV) analysis is conducted by measuring the pulse-to-pulse (PP) intervals in stationary and motion conditions. Firstly, given the importance of the sampling rate in a PRV analysis and the low frame rate of commercial cameras, we carried out an analysis of two models to evaluate their performance in the measurements. We propose a selective tracking method using the Viola–Jones and KLT algorithms, with the aim of carrying out a robust video PRV analysis in stationary and motion conditions. Data and results of the proposed method are contrasted with those reported in the state of the art. Results: The webcam achieved better results in the performance analysis of video cameras. In stationary conditions, high correlation values were obtained in PRV parameters with results above 0.9. The PP time series achieved an RMSE (mean ± standard deviation) of 19.45 ± 5.52 ms (1.70 ± 0.75 bpm). In the motion analysis, most of the PRV parameters also achieved good correlation results, but with lower values as regards stationary conditions. The PP time series presented an RMSE of 21.56 ± 6.41 ms (1.79 ± 0.63 bpm). Conclusions: The statistical analysis showed good agreement between the reference system and the proposed method. In stationary conditions, the results of PRV parameters were improved by our method in comparison with data reported in related works. An overall comparative analysis of PRV parameters in motion conditions was more limited due to the lack of studies or studies containing insufficient data analysis. Based on the results, the proposed method could provide a low-cost, contactless and reliable alternative for measuring HR or PRV parameters in non-clinical environments.Peer ReviewedPostprint (published version

    Accelerated amyloid angiopathy and related vascular alterations in a mixed murine model of Alzheimer´s disease and type two diabetes

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    Background: While aging is the main risk factor for Alzheimer´s disease (AD), emerging evidence suggests that metabolic alterations such as type 2 diabetes (T2D) are also major contributors. Indeed, several studies have described a close relationship between AD and T2D with clinical evidence showing that both diseases coexist. A hallmark pathological event in AD is amyloid-β (Aβ) deposition in the brain as either amyloid plaques or around leptomeningeal and cortical arterioles, thus constituting cerebral amyloid angiopathy (CAA). CAA is observed in 85–95% of autopsy cases with AD and it contributes to AD pathology by limiting perivascular drainage of Aβ. Methods: To further explore these alterations when AD and T2D coexist, we have used in vivo multiphoton microscopy to analyze over time the Aβ deposition in the form of plaques and CAA in a relevant model of AD (APPswe/ PS1dE9) combined with T2D (db/db). We have simultaneously assessed the effects of high-fat diet-induced prediabetes in AD mice. Since both plaques and CAA are implicated in oxidative-stress mediated vascular damage in the brain, as well as in the activation of matrix metalloproteinases (MMP), we have also analyzed oxidative stress by Amplex Red oxidation, MMP activity by DQ ™ Gelatin, and vascular functionality. Results: We found that prediabetes accelerates amyloid plaque and CAA deposition, suggesting that initial metabolic alterations may directly affect AD pathology. T2D significantly affects vascular pathology and CAA deposition, which is increased in AD-T2D mice, suggesting that T2D favors vascular accumulation of Aβ. Moreover, T2D synergistically contributes to increase CAA mediated oxidative stress and MMP activation, affecting red blood cell velocity. Conclusions: Our data support the cross-talk between metabolic disease and Aβ deposition that affects vascular integrity, ultimately contributing to AD pathology and related functional changes in the brain microvasculature.University of Cadiz Predoctoral FellowshipEuropean CommissionEuropean Commission Joint Research Centre GA 847749Programa Estatal de Generacion de Conocimiento y Fortalecimiento Cientifico y Tecnologico del Sistema de I + D + i y del Programa Estatal de I + D +i Orientada a los Retos de la Sociedad, del Plan Estatal de Investigacion Cientifica y Tecnica y de Innovaci PID2020-115499RB-I00/AEIAgencia Estatal de Investigacion (AEI) BFU 2016-75038-REuropean CommissionSpanish Government Spanish GovernmentAndalucia se mueve con Europa P20-0092

    Estrategias motivacionales en la enseñanza de geología en 2º de ESPA semipresencial. Las rocas y modelado externo del relieve

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    El presente documento es un trabajo final de master, dentro del master de Profesorado de Secundaria, Bachillerato y ciclo formativo, especialidad Biologia y Geología. Se enmarca dentro de la modalidad de enseñanza secundaria para adultos semipresencial (ESPA). En el se recogen diferentes estrategias enfocadas a la motivación del alumnado en el proceso de aprendizaje del temario correspondiente a la clasificación de rocas y modelado del relieve. Además, este trabajo contiene en los anexos actividades teóricas y prácticas que se pueden desarrollar dentro de esta unidad, enfocadas todas ellas a motivar al alumno durante el proceso de aprendizaje, incluyendo prácticas y excursiones.En los últimos tiempos la motivación se ha mostrado como uno de los grandes problemas educativos al que los docentes deben enfrentarse, siendo la geología una de las materias que menos seduce al alumnado. En este trabajo se pretende aplicar varias estrategias para incrementar la motivación en el estudio de las rocas y del modelado externo del relieve en la Educación Secundaria para adultos en una modalidad semipresencial. Del mismo modo se pretende favorecer e incentivar la comprensión lectora de los alumnos así como la expresión escrita. Las estrategias propuestas para incrementar el interés en el estudio de las ciencias son la disminución de clases magistrales frente al aumento de las sesiones prácticas y actividades participativas. Durante todo el proceso la Moodle será una herramienta fundamental en el desarrollo de actividades y en la interacción alumno-profesor y alumno-alumno.Universidad de CádizEstre trabajo consta de 106 páginas, en las que se desarrolla la unidad didactica relativa al modelado del relieve y tipos de rocas en 2º de ESPA en la que se incluyen todas las actividades a desarrollar

    Performance of likelihood ratios considering bounds on the probability of observing misleading evidence

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    This is a pre-copyedited, author-produced version of an article accepted for publication in Law, Probability & Risk following peer review. The version of record Jose Juan Lucena-Molina, Daniel Ramos-Castro, Joaquin Gonzalez-Rodriguez; Performance of likelihood ratios considering bounds on the probability of observing misleading evidence. Law, Probability and Risk 2015; 14 (3): 175-192 is available online at: http://dx.doi.org/10.1093/lpr/mgu022In this article, we introduce a new tool, namely 'Limit Tippett Plots', to assess the performance of likelihood ratios in evidence evaluation including theoretical bounds on the probability of observing misleading evidence. To do that, we first review previous work about such bounds. Then we derive 'Limit Tippett Plots' that complements Tippett plots with information about the limits on the probability of observing misleading evidence, which are taken as a reference. Thus, a much richer way to measure performance of likelihood ratios is given. Finally, we present an experimental example in forensic automatic speaker recognition following the protocols of the Acoustics Laboratory of Guardia Civil, where it can be seen that 'Limit Tippett Plots' help to detect problems in the calculation of likelihood ratios

    Metabolic Disturbance of High-Saturated Fatty Acid Diet in Cognitive Preservation

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    first_pagesettingsOrder Article Reprints Open AccessArticle Metabolic Disturbance of High-Saturated Fatty Acid Diet in Cognitive Preservation by Antonio Rivas-Domínguez 1ORCID,Himan Mohamed-Mohamed 2,Margarita Jimenez-Palomares 3ORCID,Victoria García-Morales 3ORCID,Laura Martinez-Lopez 1,Manuel Luis Orta 1,Juan José Ramos-Rodriguez 2,*,†ORCID andBeatriz Bermudez-Pulgarin 1,† 1 Department of Cellular Biology, University of Seville, 41009 Seville, Spain 2 Department of Physiology, Faculty of Health Sciences (Ceuta), University of Granada, 51001 Ceuta, Spain 3 Department of Biomedicine, Biotechnology and Public Health, University of Cádiz, 11003 Cádiz, Spain * Author to whom correspondence should be addressed. † These authors contributed equally to this work. Int. J. Mol. Sci. 2023, 24(9), 8042; https://doi.org/10.3390/ijms24098042 Received: 31 March 2023 / Revised: 16 April 2023 / Accepted: 26 April 2023 / Published: 28 April 2023 (This article belongs to the Special Issue Research on Neural and Cognitive Molecular Mechanisms of Memory and Executive Control) Download Browse Figures Review Reports Versions Notes Abstract Aging continues to be the main cause of the development of Alzheimer’s, although it has been described that certain chronic inflammatory pathologies can negatively influence the progress of dementia, including obesity and hyperlipidemia. In this sense, previous studies have shown a relationship between low-density lipoprotein receptor (LDLR) and the amyloid-beta (Aβ) binding activity, one of the main neuropathological features of Alzheimer’s disease (AD). LDLR is involved in several processes, including lipid transport, regulation of inflammatory response and lipid metabolism. From this perspective, LDLR−/− mice are a widely accepted animal model for the study of pathologies associated with alterations in lipid metabolism, such as familial hypercholesterolemia, cardiovascular diseases, metabolic syndrome, or early cognitive decline. In this context, we induced hyperlipidemia in LDLR−/− mice after feeding with a high-saturated fatty acid diet (HFD) for 44 weeks. LDLR−/−-HFD mice exhibited obesity, hypertriglyceridemia, higher glucose levels, and early hepatic steatosis. In addition, HFD increased plasmatic APOE and ubiquitin 60S levels. These proteins are related to neuronal integrity and health maintenance. In agreement, we detected mild cognitive dysfunctions in mice fed with HFD, whereas LDLR−/−-HFD mice showed a more severe and evident affectation. Our data suggest central nervous system dysfunction is associated with a well-established metabolic syndrome. As a late consequence, metabolic syndrome boots many behavioral and pathological alterations recognized in dementia, supporting that the control of metabolic parameters could improve cognitive preservation and prognosis.Junta de Andalucía, Spain, grant number P18-RT-3324P20-01061 from Junta de Andalucía, SpainPID2019- 110960GB-I00 from the Ministry of Science and Innovation, Spai

    Current Treatments and New, Tentative Therapies for Parkinson’s Disease

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    Parkinson's disease (PD) is a neurodegenerative pathology, the origin of which is associated with the death of neuronal cells involved in the production of dopamine. The prevalence of PD has increased exponentially. The aim of this review was to describe the novel treatments for PD that are currently under investigation and study and the possible therapeutic targets. The pathophysiology of this disease is based on the formation of alpha-synuclein folds that generate Lewy bodies, which are cytotoxic and reduce dopamine levels. Most pharmacological treatments for PD target alpha-synuclein to reduce the symptoms. These include treatments aimed at reducing the accumulation of alpha-synuclein (epigallocatechin), reducing its clearance via immunotherapy, inhibiting LRRK2, and upregulating cerebrosidase (ambroxol). Parkinson's disease continues to be a pathology of unknown origin that generates a significant social cost for the patients who suffer from it. Although there is still no definitive cure for this disease at present, there are numerous treatments available aimed at reducing the symptomatology of PD in addition to other therapeutic alternatives that are still under investigation. However, the therapeutic approach to this pathology should include a combination of pharmacological and non-pharmacological strategies to maximise outcomes and improve symptomatological control in these patients. It is therefore necessary to delve deeper into the pathophysiology of the disease in order to improve these treatments and therefore the quality of life of the patients.Junta de Andalucia P18-RT-3324 P20-01293 P20-01061Ministry of Science and Innovation, Spain (MICINN) Spanish Government PID2019-110960GB-I0

    Autoignition of sustainable fuels under dual operation with H<sub>2</sub>-carriers in a constant volume combustion chamber

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    The expected increase in the use of environmentally friendly liquid fuels in medium and heavy-duty compression ignition engines (for both off-road and transport applications), together with the well-documented benefits of hydrogen-carriers to decrease energy dependence and to achieve a neutral-carbon economy (internal combustion engines highly contributing to the global CO2 emissions), have motivated this work. The autoignition characteristics of different alternative diesel-type fuels (hydrotreated vegetable oil, advanced biodiesel and blends of conventional diesel fuel with polyoxymethylene dimethyl ether and 1-butanol) under dual-fuel operation with H2, NH3, and CH4 were studied in a constant volume combustion chamber at 535 and 600 °C. The high reactivity fuel was replaced by the gaseous fuel up to 40 % by energy. The main ignition delay time was significantly affected not only by the type of low reactivity fuel, with ammonia considerably retarding autoignition, but also by the nature of the liquid fuel, biodiesel being the less sensitive to the presence of the H2-carrier fuel. Results also proved that the higher the reactivity of the diesel-type fuel (quantified through the cetane number), the lower the influence of the gaseous fuel on the autoignition time.El aumento previsto en el uso de combustibles líquidos inocuos para el medio ambiente en motores de encendido por compresión de servicio mediano y pesado (tanto para aplicaciones todoterreno como de transporte), junto con los beneficios bien documentados de los vehículos de hidrógeno para disminuir la dependencia energética y lograr un economía neutral en carbono (motores de combustión interna que contribuyen en gran medida a las emisiones globales de CO 2 ), han motivado este trabajo. Las características de autoignición de diferentes combustibles alternativos de tipo diesel (aceite vegetal hidrotratado, biodiesel avanzado y mezclas de combustible diesel convencional con polioximetilen dimetil éter y 1-butanol) en operación de combustible dual con H 2 , NH 3 y CH 4fueron estudiados en una cámara de combustión de volumen constante a 535 y 600 °C. El combustible de alta reactividad fue reemplazado por el combustible gaseoso hasta en un 40 % por energía. El tiempo de retardo del encendido principal se vio significativamente afectado no solo por el tipo de combustible de baja reactividad, con el amoníaco retardando considerablemente el autoencendido, sino también por la naturaleza del combustible líquido, siendo el biodiesel el menos sensible a la presencia del combustible portador de H 2 . Los resultados también demostraron que cuanto mayor es la reactividad del combustible tipo diésel (cuantificada a través del número de cetano), menor es la influencia del combustible gaseoso en el tiempo de autoignición

    A functional renormalization group application to the scanning tunneling microscopy experiment

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    Abstract: We present a study of a system composed of a scanning tunneling microscope (STM) tip coupled to an absorbed impurity on a host surface using the functional renormalization group (FRG). We include the effect of the STM tip as a correction to the self-energy in addition to the usual contribution of the host surface in the wide band limit. We calculate the differential conductance curves at two different lateral distances from the quantum impurity and find good qualitative agreement with STM experiments where the differential conductance curves evolve from an antiresonance to a Lorentzian shape

    A data mining framework based on boundary-points for gene selection from DNA-microarrays: Pancreatic Ductal Adenocarcinoma as a case study

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    [EN] Gene selection (or feature selection) from DNA-microarray data can be focused on different techniques, which generally involve statistical tests, data mining and machine learning. In recent years there has been an increasing interest in using hybrid-technique sets to face the problem of meaningful gene selection; nevertheless, this issue remains a challenge. In an effort to address the situation, this paper proposes a novel hybrid framework based on data mining techniques and tuned to select gene subsets, which are meaningfully related to the target disease conducted in DNA-microarray experiments. For this purpose, the framework above deals with approaches such as statistical significance tests, cluster analysis, evolutionary computation, visual analytics and boundary points. The latter is the core technique of our proposal, allowing the framework to define two methods of gene selection. Another novelty of this work is the inclusion of the age of patients as an additional factor in our analysis, which can leading to gaining more insight into the disease. In fact, the results reached in this research have been very promising and have shown their biological validity. Hence, our proposal has resulted in a methodology that can be followed in the gene selection process from DNA-microarray data

    Architecture, design and source code comparison of ns-2 and ns-3 network simulators

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    Ns-2 and its successor ns-3 are discrete-event simulators. Ns- 3 is still under development, but offers some interesting characteristics for developers while ns-2 still has a big user base. This paper remarks current differences between both tools from developers point of view. Leaving performance and resources consumption aside, technical issues described in the present paper might help to choose one or another alternative depending of simulation and project management requirements.Ministerio de Educación y Ciencia TIN2006-15617-C03-03Junta de Andalucía P06-TIC-229
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