133 research outputs found

    Diferenciación de clases de ocupación del suelo según su multiangularidad

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    Desde los años 70 se conoce que la reflectancia de las distintas ocupaciones del suelo varía según los ángulos de observación e iluminación, es decir, las cubiertas son anisotrópicas. Por tanto, la geometría de captación es un condicionante importante a tener en cuenta a la hora de analizar las imágenes captadas, pero al mismo tiempo se podría aprovechar lo que tal anisotropía nos infiere. A este respecto, existen varios trabajos que hablan de la capacidad de estimar características estructurales de la vegetación y caracterizar distintas ocupaciones del suelo, utilizando variables multiangulares. El objetivo del presente trabajo es evaluar la posibilidad en primera instancia, de poder diferenciar distintas ocupaciones del suelo a partir de la información multiangular que nos proporciona el sensor Multi Angle Spectro Radiometer (MISR) a bordo del satélite TERRA.Para ello se ha trabajado con el producto elaborado MISR L2 Land Surface de 1.1 km de pixel, que proporciona los parámetros ρ, Θ y k para cuatro bandas, azul, verde, rojo e infrarrojo cercano, del modelo RPV, un modelo semiempírico de factor de reflectancia bidireccional (BRF). Los datos utilizados son de fecha 21/7/2005, para píxeles puros de CORINE Land Cover 2006 de la España peninsular. Los resultados muestran que las clases agrícolas tienen medias significativamente más bajas para el parámetro ρ y más altas para los parámetros Θ y k que las clases forestales para todas las bandas. Tales resultados invitan a pensar que la multiangularidad puede ayudar a la hora de mejorar las clasificaciones de imágenes y determinar estructuras en las ocupaciones del suelo

    Digital Data Sources and Their Impact on People's Health: A Systematic Review of Systematic Reviews

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    Background: Digital data sources have become ubiquitous in modern culture in the era of digital technology but often tend to be under-researched because of restricted access to data sources due to fragmentation, privacy issues, or industry ownership, and the methodological complexity of demonstrating their measurable impact on human health. Even though new big data sources have shown unprecedented potential for disease diagnosis and outbreak detection, we need to investigate results in the existing literature to gain a comprehensive understanding of their impact on and benefits to human health. / Objective: A systematic review of systematic reviews on identifying digital data sources and their impact area on people's health, including challenges, opportunities, and good practices. Methods: A multidatabase search was performed. Peer-reviewed papers published between January 2010 and November 2020 relevant to digital data sources on health were extracted, assessed, and reviewed. / Results: The 64 reviews are covered by three domains, that is, universal health coverage (UHC), public health emergencies, and healthier populations, defined in WHO's General Programme of Work, 2019-2023, and the European Programme of Work, 2020-2025. In all three categories, social media platforms are the most popular digital data source, accounting for 47% (N = 8), 84% (N = 11), and 76% (N = 26) of studies, respectively. The second most utilized data source are electronic health records (EHRs) (N = 13), followed by websites (N = 7) and mass media (N = 5). In all three categories, the most studied impact of digital data sources is on prevention, management, and intervention of diseases (N = 40), and as a tool, there are also many studies (N = 10) on early warning systems for infectious diseases. However, they could also pose health hazards (N = 13), for instance, by exacerbating mental health issues and promoting smoking and drinking behavior among young people. / Conclusions: The digital data sources presented are essential for collecting and mining information about human health. The key impact of social media, electronic health records, and websites is in the area of infectious diseases and early warning systems, and in the area of personal health, that is, on mental health and smoking and drinking prevention. However, further research is required to address privacy, trust, transparency, and interoperability to leverage the potential of data held in multiple datastores and systems. This study also identified the apparent gap in systematic reviews investigating the novel big data streams, Internet of Things (IoT) data streams, and sensor, mobile, and GPS data researched using artificial intelligence, complex network, and other computer science methods, as in this domain systematic reviews are not common

    The Response of Governments and Public Health Agencies to COVID-19 Pandemics on Social Media: A Multi-Country Analysis of Twitter Discourse

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    During the COVID-19 pandemic, information is being rapidly shared by public health experts and researchers through social media platforms. Whilst government policies were disseminated and discussed, fake news and misinformation simultaneously created a corresponding wave of "infodemics." This study analyzed the discourse on Twitter in several languages, investigating the reactions to government and public health agency social media accounts that share policy decisions and official messages. The study collected messages from 21 official Twitter accounts of governments and public health authorities in the UK, US, Mexico, Canada, Brazil, Spain, and Nigeria, from 15 March to 29 May 2020. Over 2 million tweets in various languages were analyzed using a mixed-methods approach to understand the messages both quantitatively and qualitatively. Using automatic, text-based clustering, five topics were identified for each account and then categorized into 10 emerging themes. Identified themes include political, socio-economic, and population-protection issues, encompassing global, national, and individual levels. A comparison was performed amongst the seven countries analyzed and the United Kingdom (Scotland, Northern Ireland, and England) to find similarities and differences between countries and government agencies. Despite the difference in language, country of origin, epidemiological contexts within the countries, significant similarities emerged. Our results suggest that other than general announcement and reportage messages, the most-discussed topic is evidence-based leadership and policymaking, followed by how to manage socio-economic consequences

    Los sistemas de pago por servicios ambientales entre la adicionalidad y la subsidiariedad: aplicación a la belleza escénica en el pantano de San Juan, Madrid, España

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    A payment for environmental services (PES) based on the beauty of the San Juan dam landscape is proposed containing two innovative aspect in regard to previous PES systems: the elaboration of a diagnosis oriented to obtain a shared vision of the area based in a participative process including all relevant local stakeholders, and the integration of the PES mechanism into the regional public environmental policy. The proposed system also identifies the offer and the demand of the environmental service. It shows the main problems associated to the preservation of the service and proposes management plans oriented to its conservation. Finally, the economic viability of the system is studied comparing three different scenarios according to the grade of integration of the PES model into the regional conservation public policy. This paper shows how a PES system can be used to guarantee public investments in nature conservation through a private management.Se plantea un sistema de pago por servicios ambientales (PSA) basado en la valoración de la belleza escénica en la zona del pantano de San Juan, Madrid, con dos aspectos novedosos respecto a estudios PSA previos: la elaboración de un diagnóstico basado en un proceso participativo que involucra a todos los actores sociales locales y cuyo fin es el de obtener una visión compartida sobre el área, y la integración del mecanismo PSA en la gestión pública regional de la conservación de la naturaleza. El sistema propuesto además identifica los oferentes y demandantes del servicio ambiental, muestra los principales problemas asociados a la conservación del servicio y plantea programas de gestión orientados a contribuir a su conservación. Se estudia, por último, la viabilidad económica del sistema comparando tres escenarios hipotéticos en función del grado de integración del sistema PSA en las políticas públicas de conservación de la naturaleza regionales. El trabajo muestra como un sistema PSA puede servir para garantizar las inversiones públicas en conservación a través de la gestión privada

    Estrogenicity of resin-based composites and sealants used in dentistry.

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    We tested some resin-based composites used in dentistry for their estrogenic activity. A sealant based on bisphenol-A diglycidylether methacrylate (bis-GMA) increased cell yields, progesterone receptor expression, and pS2 secretion in human estrogen-target, serum-sensitive MCF7 breast cancer cells. Estrogenicity was due to bisphenol-A and bisphenol-A dimethacrylate, monomers found in the base paste of the dental sealant and identified by mass spectrometry. Samples of saliva from 18 subjects treated with 50 mg of a bis-GMA-based sealant applied on their molars were collected 1 hr before and after treatment. Bisphenol-A (range 90-931 micrograms) was identified only in saliva collected during a 1-hr period after treatment. The use of bis-GMA-based resins in dentistry, and particularly the use of sealants in children, appears to contribute to human exposure to xenoestrogens

    Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases

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    Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests

    Global potential energy surface for the O2 + N2 interaction. Applications to the collisional, spectroscopic, and thermodynamic properties of the complex

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    A detailed characterization of the interaction between the most abundant molecules in air is important for the understanding of a variety of phenomena in atmospherical science. A completely {\em ab initio} global potential energy surface (PES) for the O2(3Σg)_2(^3\Sigma^-_g) + N2(1Σg+)_2(^1\Sigma^+_g) interaction is reported for the first time. It has been obtained with the symmetry-adapted perturbation theory utilizing a density functional description of monomers [SAPT(DFT)] extended to treat the interaction involving high-spin open-shell complexes. The computed interaction energies of the complex are in a good agreement with those obtained by using the spin-restricted coupled cluster methodology with singles, doubles and noniterative triple excitations [RCCSD(T)]. A spherical harmonics expansion containing a large number of terms due to the anisotropy of the interaction has been built from the {\em ab initio} data. The radial coefficients of the expansion are matched in the long range with the analytical functions based on the recent {\em ab initio} calculations of the electric properties of the monomers [M. Bartolomei et al., J. Comp. Chem., {\bf 32}, 279 (2011)]. The PES is tested against the second virial coefficient B(T)B(T) data and the integral cross sections measured with rotationally hot effusive beams, leading in both cases to a very good agreement. The first bound states of the complex have been computed and relevant spectroscopic features of the interacting complex are reported. A comparison with a previous experimentally derived PES is also provided

    Complementary regulation of four Eucalyptus CBF genes under various cold conditions

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    CBF transcription factors play central roles in the control of freezing tolerance in plants. The isolation of two additional CBF genes, EguCBF1c and EguCBF1d, from E. gunnii, one of the cold-hardiest Eucalyptus species, is described. While the EguCBF1D protein sequence is very similar to the previously characterized EguCBF1A and EguCBF1B sequences, EguCBF1C is more distinctive, in particular in the AP2-DBD (AP2-DNA binding domain). The expression analysis of the four genes by RT-qPCR reveals that none of them is specific to one stress but they are all preferentially induced by cold, except for the EguCBF1c gene which is more responsive to salt. The calculation of the transcript copy number enables the quantification of constitutive CBF gene expression. This basal level, significant for the four genes, greatly influences the final EguCBF1 transcript level in the cold. A cold shock at 4 °C, as well as a progressive freezing which mimics a natural frost episode, trigger a fast and strong response of the EguCBF1 genes, while growth at acclimating temperatures results in a lower but more durable induction. The differential expression of the four EguCBF1 genes under these cold regimes suggests that there is a complementary regulation. The high accumulation of the CBF transcript, observed in response to the different types of cold conditions, might be a key for the winter survival of this evergreen broad-leaved tree
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