60 research outputs found

    High order extensions of Roe schemes for two dimensional nonconservative hyperbolic systems

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    This paper is concerned with the development of well-balanced high order Roe methods for two-dimensional nonconservative hyperbolic systems. In particular, we are interested in extending the methods introduced in [3] to the two-dimensional case. We also investigate the well-balance properties and the consistency of the resulting schemes. We focus in applications to one and two layer shallow water system

    An electronic nose as a non-destructive analytical tool to identify the geographical origin of portuguese olive oils from two adjacent regions

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    The geographical traceability of extra virgin olive oils (EVOO) is of paramount importance for oil chain actors and consumers. Oils produced in two adjacent Portuguese regions, Côa (36 oils) and Douro (31 oils), were evaluated and fulfilled the European legal thresholds for EVOO categorization. Compared to the Douro region, oils from Côa had higher total phenol contents (505 versus 279 mg GAE/kg) and greater oxidative stabilities (17.5 versus 10.6 h). The majority of Côa oils were fruity-green, bitter, and pungent oils. Conversely, Douro oils exhibited a more intense fruity-ripe and sweet sensation. Accordingly, different volatiles were detected, belonging to eight chemical families, from which aldehydes were the most abundant. Additionally, all oils were evaluated using a lab-made electronic nose, with metal oxide semiconductor sensors. The electrical fingerprints, together with principal component analysis, enabled the unsupervised recognition of the oils’ geographical origin, and their successful supervised linear discrimination (sensitivity of 98.5% and specificity of 98.4%; internal validation). The E-nose also quantified the contents of the two main volatile chemical classes (alcohols and aldehydes) and of the total volatiles content, for the studied olive oils split by geographical origin, using multivariate linear regression models (0.981 < R2 < 0.998 and 0.40 < RMSE < 2.79 mg/kg oil; internal validation). The E-nose-MOS was shown to be a fast, green, non-invasive and cost-effective tool for authenticating the geographical origin of the studied olive oils and to estimate the contents of the most abundant chemical classes of volatiles.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020), to CEB (UIDB/04469/2020) and to the Associate Laboratory SusTEC (LA/P/0007/2020). The authors are also grateful to the “Project OLIVECOA—Centenarian olive trees of Côa Valley region: rediscovering the past to valorize the future” (ref. COA/BRB/0035/2019), financed by FCT (Portugal). Nuno Rodrigues thanks the National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

    Electronic nose: a tool to verify the PDO declaration of Portuguese olive oils

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    The volatile and olfactory profiles of three Portuguese olive oils with protected designations of origin (PDO) were studied: "Azeite do Alentejo Interior", "Azeites da Beira Interior", and "Azeite de Tras-os-Montes". Seven classes of volatiles were identified, with aldehydes, followed by hydrocarbons and alcohols, the most prevalent (5.63, 2.92, and 2.79 mg/kg olive oil, respectively). The "Azeites da Beira Interior" oils exhibited the highest amount of volatiles (18.2 +/- 4.6 mg/kg olive oil) compared to the oils from the other two PDOs. Ten positive olfactory sensations were detected, and a significant effect of the PDO on the intensities of fruity, apple, cabbage, tomato, dry and fresh herbs was observed. Specifically, "Azeite do Alentejo Interior" PDO oils were characterized as fruity-ripe, while "Azeite de Tras-os-Montes" PDO oils were labelled as fruity-green. Conversely, "Azeites da Beira Interior" PDO oils encompassed both fruity-ripe and fruity-green oils. Unique volatile and olfactory fingerprints were established for each PDO, allowing the linear discrimination of the oils according to the PDO, with a predictive sensitivity of 98.0 +/- 4.2% (repeated K-fold-CV). Furthermore, a lab-made electronic nose successfully discriminated the studied oils based on the PDO, with a predictive accuracy of 99.7 +/- 2.0% (repeated K-fold-CV). This device also allowed predicting the concentrations of the three main volatile classes found in the oils through multiple linear regression models (R2 >= 0.923 +/- 0.101 and RMSE <= 1.32 +/- 0.72 mg/kg oil; repeated K-fold-CV). These findings underscore the potential of the electronic nose as a reliable traceability tool to authenticate the PDO declaration of Portuguese olive oils, and broaden its use beyond non-PDO oils from a specific geographical area to encompass a national scale.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020, https://doi.org/10.54499/UIDB/00690/2020; and UIDP/00690/2020, https://doi.org/10.54499/UIDP/00690/2020) and CEB (UIDB/04469/2020) units as well as to the Associate Laboratory SusTEC (LA/P/0007/2020, https://doi.org/10.54499/LA/P/0007/2020). The authors are also grateful to the "Project OLIVE4ALL-Olive Heritage for Sustainable Development: Raising Community Awareness of Living Heritage" (ref. JPICH/0001/2020, https://doi.org/10.54499/JPICH/0001/2020), financed by FCT (Portugal). Nuno Rodrigues thanks the FCT- Foundation for Science and Technology, P.I., for the National funding through the institutional program contract for scientific employment. Nuno Ferreiro also acknowledges the Ph.D. research grant (2022.10072.BD) provided by FCT.info:eu-repo/semantics/publishedVersio

    Qualidade e atividade antioxidante de azeites extraídos de frutos atacados por gafa e mosca da azeitona

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    A mosca da azeitona e a gafa, são respetivamente a principal praga e doença que atacam as azeitonas nos olivais Portugueses, causando enormes prejuízos, não apenas na quantidade, mas também na qualidade dos produtos obtidosOs autores agradecem à Fundação para a Ciência e Tecnologia (FCT, Portugal) o apoio financeiro dos fundos nacionais FCT / MCTES ao CIMO (UIDB/00690/2020 e UIDP/00690/2020) e ao SusTEC (LA/P/0007/2020). Nuno Rodrigues agradece ao financiamento da FCT- Fundação para a Ciência e Tecnologia, P.I., através do contrato-programa institucional de emprego científico.info:eu-repo/semantics/publishedVersio

    Integrating belowground carbon dynamics into Yield-SAFE, a parameter sparse agroforestry model

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    Agroforestry combines perennial woody elements (e.g. trees) with an agricultural understory (e.g. wheat, pasture) which can also potentially be used by a livestock component. In recent decades, modern agroforestry systems have been proposed at European level as land use alternatives for conventional agricultural systems. The potential range of benefits that modern agroforestry systems can provide includes farm product diversification (food and timber), soil and biodiversity conservation and carbon sequestration, both in woody biomass and the soil. Whilst typically these include benefits such as food and timber provision, potentially, there are benefits in the form of carbon sequestration, both in woody biomass and in the soil. Quantifying the effect of agroforestry systems on soil carbon is important because it is one means by which atmospheric carbon can be sequestered in order to reduce global warming. However, experimental systems that can combine the different alternative features of agroforestry systems are difficult to implement and long-term. For this reason, models are needed to explore these alternatives, in order to determine what benefits different combinations of trees and understory might provide in agroforestry systems. This paper describes the integration of the widely used soil carbon model RothC, a model simulating soil organic carbon turnover, into Yield-SAFE, a parameter sparse model to estimate aboveground biomass in agroforestry systems. The improvement of the Yield-SAFE model focused on the estimation of input plant material into soil (i.e. leaf fall and root mortality) while maintaining the original aspiration for a simple conceptualization of agroforestry modeling, but allowing to feed inputs to a soil carbon module based on RothC. Validation simulations show that the combined model gives predictions consistent with observed data for both SOC dynamics and tree leaf fall. Two case study systems are examined: a cork oak system in South Portugal and a poplar system in the UK, in current and future climate. (c) 2017, Springer Science+Business Media B.V.European Commission through the AGFORWARD FP7 research Project (contract 613520), Forest Research Center strategic Project (PEst OE/AGR/UI0239/2014), the Portuguese Foundation for Science and Technology (FCT) fellowships SFRH/BD/52691/2014 and SFRH/BPD/96475/2013, XUNTA DE GALICIA, Consellería de Cultura, Educación e Ordenación Universitaria (“Programa de axudas á etapa posdoutoral”) (contract ED481B 2016/071-0

    From local monitoring to a broad‐scale viability assessment: a case study for the Bonelli's Eagle in western Europe

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    Population viability analysis (PVA) has become a basic tool of current conservation practice. However, if not accounted for properly, the uncertainties inherent to PVA predictions can decrease the reliability of this type of analysis. In the present study, we performed a PVA of the whole western European population (France, Portugal, and Spain) of the endangered Bonelli's Eagle (Aquila fasciata), in which we thoroughly explored the consequences of uncertainty in population processes and parameters on PVA predictions. First, we estimated key vital rates (survival, fertility, recruitment, and dispersal rates) using monitoring, ringing, and bibliographic data from the period 1990-2009 from 12 populations found throughout the studied geographic range. Second, we evaluated the uncertainty about model structure (i.e., the assumed processes that govern individual fates and population dynamics) by comparing the observed growth rates of the studied populations with model predictions for the same period. Third, using the model structures suggested in the previous step, we assessed the viability of both the local populations and the overall population. Finally, we analyzed the effects of model and parameter uncertainty on PVA predictions. Our results strongly support the idea that all local populations in western Europe belong to a single, spatially structured population operating as a source-sink system, whereby the populations in the south of the Iberian Peninsula act as sources and, thanks to dispersal, sustain all other local populations, which would otherwise decline. Predictions regarding population dynamics varied considerably, and models assuming more constrained dispersal predicted more pessimistic population trends than models assuming greater dispersal. Model predictions accounting for parameter uncertainty revealed a marked increase in the risk of population declines over the next 50 years. Sensitivity analyses indicated that adult and pre‐adult survival are the chief vital rates regulating these populations, and thus, the conservation efforts aimed at improving these survival rates should be strengthened in order to guarantee the long‐term viability of the European populations of this endangered species. Overall, the study provides a framework for the implementation of multi‐site PVAs and highlights the importance of dispersal processes in shaping the population dynamics of long‐lived birds distributed across heterogeneous landscapes

    Recommendations for ophthalmologic practice during the easing of COVID-19 control measures

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    In the context of the COVID-19 pandemic, this paper provides recommendations for medical eye care during the easing of control measures after lockdown. The guidelines presented are based on a literature review and consensus among all Spanish Ophthalmology Societies regarding protection measures recommended for the ophthalmologic care of patients with or without confirmed COVID-19 in outpatient, inpatient, emergency and surgery settings. We recommend that all measures be adapted to the circumstances and availability of personal protective equipment at each centre and also highlight the need to periodically update recommendations as we may need to readopt more restrictive measures depending on the local epidemiology of the virus. These guidelines are designed to avoid the transmission of SARS-CoV-2 among both patients and healthcare staff as we gradually return to normal medical practice, to prevent postoperative complications and try to reduce possible deficiencies in the diagnosis, treatment and follow-up of the ophthalmic diseases. With this update (5th) the Spanish Society of Ophthalmology is placed as one of the major ophthalmology societies providing periodic and systematized recommendations for ophthalmic care during the COVID-19 pandemic

    Identificación de los Indicadores de seguimiento de las acciones de conservación. Acción A1 “Diagnosis, Análisis territorial e Identificación de Indicadores"

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    Las acciones de conservación de LIFE FLUVIAL precisan de una evaluación periódica de sus repercusiones sobre el hábitat 91E0* y el hábitat 9230 (los dos hábitats objetivo del proyecto). Cada socio en sus territorios debe llevar a cabo un seguimiento con motivo de la acción D1 que permita evaluar la efectividad de las actuaciones de restauración (acciones C) y realizar una toma de decisiones de acuerdo a los resultados de dicho monitoreo, que pueda incluir cambios en las actuaciones previstas o la ejecución de nuevas medidas. En consecuencia, en el presente documento se establecen los indicadores de seguimiento a emplear en la acción D1 de LIFE FLUVIAL, así como la metodología para su aplicación. Los objetivos del seguimiento son: A. Vigilar la evolución del proceso de restauración B. Controlar los cambios que se produzcan C. Detectar y corregir la aparición de efectos indeseables D. Favorecer los procesos que se entiendan beneficiosos para recuperar la naturalidad y biodiversidad del lugar. En todo caso, hay que tener en cuenta que la duración del proyecto se queda corta para poder abarcar todo el proceso de recuperación de la cubierta vegetal propiciado por las acciones de conservación, de modo que, probablemente, los resultados del seguimiento relativos a algunos parámetros no presentarán valores especialmente significativos, debiendo interpretarse entonces como tendencias de la evolución de los hábitats objetivo en los enclaves de actuación.info:eu-repo/semantics/publishedVersio
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