293 research outputs found

    Biomoléculas em cogumelos silvestres do Nordeste de Portugal: função nutricional e medicinal

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    A procura de alimentos que tenham a capacidade de melhorar a nossa saúde e reduzir o risco de doenças tem vindo, progressivamente, a ganhar interesse. Os cogumelos podem ser um exemplo desses alimentos, apresentando ainda a vantagem de serem reconhecidos como uma iguaria. Esta característica pode colocar os cogumelos na interface farmacologia- nutrição. Neste estudo, foram caracterizadas oito espécies de cogumelos em termos nutricionais (proteínas, glúcidos, lípidos, açúcares individuais e ácidos gordos) e de compostos bioativos (tocoferóis, carotenoides, ácidos orgânicos e compostos fenólicos) com propriedades antioxidantes. As propriedades medicinais são frequentemente relacionadas com o potencial antioxidante apresentado pelos extratos de cogumelos. Boletus regius foi a espécie com maior teor de glúcidos (88,79 g/ 100g dw) e PUFA (56,55 %), compostos bioativos como tocoferóis (736,80 μg/ 100g dw), ácido cítrico (3,32 g/ 100 g dw) e compostos fenólicos (23,49 mg/ 100 g dw), incluindo 2 derivados da crisina, apresentando também elevada atividade antioxidante. Os compostos bioativos identificados poderão ser usados como nutracêuticos para prevenir doenças crónicas relacionadas com o stresse oxidativo. Além disso, todas as espécies testadas são comestíveis e poderão ser incorporadas diretamente na dieta como alimentos funcionais.The search for foods that might improve health or reduce disease risk, has been progressively gaining interest. Mushroom could be examples of these foods, presenting the additional advantage of being recognized as a delicacy. This feature might place mushrooms in the pharma-nutrition interface. Herein, eight different mushroom species were characterized in terms of nutrients (proteins, carbohydrates, fat, individual sugars, fatty acids) and bioactive compounds (tocopherols, carotenoids, organic acids and phenolic compounds) with recognized antioxidant properties. The medicinal properties are often related with the antioxidant potential presented by mushroom extracts. Boletus regius was the species with the highest levels of carbohydrates (88.79 g/ 100 g dw) and PUFA (56.55%), bioactive compounds such as tocopherols (763.80 μg/100 g dw), citric acid (3.32 g/ 100 g dw) and phenolic compounds (23.49 mg/ 100 g dw), including two chrysin derivatives, presenting also the highest antioxidant activity. The identified bioactive compounds might be used as nutraceuticals to prevent chronic diseases related with oxidative stress. Furthermore, all tested species are edible, and could be incorporated directly in diet acting as functional foods.Este trabalho insere-se no projeto de investigação PTDC/AGR-ALI/110062/2009, financiado pela Fundação para a Ciência e Tecnologia (FCT, Portugal) e pelo Programa COMPETE/QREN/EU

    De pequenino se torce o pepino : processos de mediação entre as experiências de infância e as relações de casal

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    Tese de mestrado, Psicologia (Psicologia Clínica e da Saúde - Núcleo de Psicologia Clínica Dinâmica), Universidade de Lisboa, Faculdade de Psicologia e de Ciências da Educação, 200

    Design of DMRS schemes for 5G vehicular communications

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    Proceeding of: 2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), 25-28 April 2021, Helsinki, Finland (Virtual edition)The arrival of the fifth generation (5G) of mobile communications is boosting vehicular communications, an important use case addressed in the recent years. LTE introduced a sidelink radio interface through which user equipment would communicate directly with no necessary dependence on the network, named PC5. 5G has defined its own sidelink interface, NR-Sidelink, envisaged to improve PC5. This paper analyses the use of Demodulation Reference Signals (DMRS) to estimate the channel in sidelink communications. Improving several mappings proposed by the standards, the main contribution proposed in this paper is a new DMRS mapping with a better performance. The proposed Unequal Pilot Spacing (UPS) mapping can enhance the standard with a satisfactory trade-off between performance and overhead.This work has been supported by the Spanish National Project TERESA-ADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE)

    Reducing the interference by adapting the power of OFDM for mMTC

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    Proceedings of: 2018 IEEE 87th Vehicular Technology Conference (VTC Spring)The Fifth Generation of mobile communications (5G) is being standardized based on Orthogonal Frequency Division Multiplexing (OFDM) waveforms. The high out-of-band emissions (OBE) are one of the main drawbacks of OFDM, which reduce the spectral efficiency and force us to leave wide guard bands. A strong candidate to replace OFDM is filtered-OFDM (f-OFDM) which solves the mentioned issue and keeps the backward compatibility. However, it increments the inter-symbol interference (ISI) due to the use of digital filters. We propose a new technique to overcome this problem. It is based on shaping the power of OFDM by the scheduler according to the demanded rates and channel quality of the users, while decreasing the OBE and avoiding the ISI increase. The interference generated by our proposed technique on a narrow-band signal based on legacy OFDM is analyzed. Moreover, simulations are performed to validate the theoretical analysis and some examples of implementation are also provided in the context of 5G evolution.This work has been partly funded by projects MACHINE (TSI-100102-2015-17), TERESA-ADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE) and ELISA (TEC2014-59255-C3-3-R)

    Análisis de prestaciones de eMBMS en LTE: redes de frecuencia única

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    La ponencia presentada en: XXVIII Simposium Nacional de la Unión Científica Internacional de Radio. URSI 2013. Santiago de Compostela, 11-13 Sept. 2013.Mobile video is one of the most popular uses for mobile broadband networks. Based upon evolved Multimedia Broadcast Multicast Service (eMBMS) available with 3GPP release 9, LTE can provide broadcast/multicast content delivery with a single-frequency network mode that send the same multimedia content to mass audience within a specific area. In this paper, we carry out a Signal to Interference plus Noise Ratio (SINR) performance analysis for this type of networks, using OPNET Modeler tool. Several scenarios have been considered, with different number of users receiving multicast video data from the same source and different number of eNodeBs. This study includes the comparison of SINR in scenarios with 1, 3 and 7 different frequencies using multicast without MBMS or with MBMS SFN. The results show a comparison in the cell throughput between the different scenarios, as well as the performance obtained using different sizes of MBMS SFN areas.Este trabajo ha sido en parte financiado por el Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, proyecto LTExtreme (IPT-2012- 0525-430000).Publicad

    Joint multicast/unicast scheduling with dynamic optimization for LTE multicast service

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    This proceeding at: European Wireless 2014, took place 2014 Mai, 14-16, in Barcelona (España). The event web site of http://www.ew2014.org/Mobile video service is one of the most increasing uses expected in future generation cellular networks, including multicast video services. Based upon Evolved Multimedia Broadcast and Multicast Service (eMBMS) available with 3rd Generation Partnership Project (3GPP) release 9, Long Term Evolution (LTE) can provide broadcast/multicast content delivery with a single-frequency network mode. This means sending the same multimedia content to a mass audience within a specific area. However, it is not always possible to use multicast transmission to every user because of their different channel conditions, so unicast transmission should also be used to fulfill Quality of Service (QoS) requirements for multicast services. This paper proposes a Joint Multicast/Unicast Scheduling (JMUS) strategy for multicast service delivery. This method is based on dynamic optimization at each LTE frame, obtaining the optimal Modulation and Coding Scheme (MCS) for multicast transmission, the optimal number of subframes reserved for multicast transmission and allocating the remaining resources using a unicast scheduling metric for guaranteed data-rate. The goal of the scheduling technique proposed is to maximize the overall throughput, guaranteeing a target bit rate for all the users in the area. A new JMUS with dynamic optimization is presented to improve QoS performance. Finally, a fast search algorithm is evaluated to approach the optimal values for dynamic optimization with an order of magnitude fewer iterations than using exhaustive search.This work was supported in part by the Spanish Min-istry of Economy and Competitiveness, National Plan for Scienti?c Research, Development and Technological Inno-vation (INNPACTO subprogram), LTExtreme project (IPT- 2012-0525-430000) and the subproject TEC2011-29006-C03-03 (GRE3N-SYST).Publicad

    Resource Allocation Management for Broadcast/Multicast Services

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    Ponencia presentada en: XXX Simposium Nacional de la Unión Científica Internacional de Radio, los dias 2 y 4 septiembre 2015, en Pamplona (españa).Video services are expected to become more than 70% of the mobile traffic in 2020. Broadcast and multicast service is the most efficient mechanism to deliver the same content to many users. Not only focusing on venue casting, but also distributing many other media such as software updates and breaking news, 5G broadcasting is a key driver to achieve the spectral efficiency needed for the 1,000 times traffic growth that is expected for the upcoming years. Improvements in some areas, such as resource allocation techniques for broadcast/multicast services, are needed. The utilization of the Conventional Multicast Scheme (CMS) approach for multicast resource allocation presents intrinsic inefficiencies, because of the different channel conditions of the users which demand the service. This paper presents some resource allocation strategies based on the use of multicast subgroups. We propose a multicast resource allocation algorithm including memory, which results in improvements of the service throughput at the time a high fairness among the users is guaranteed. In addition, an algorithm of joint resource allocation among multicast and unicast transmissions is developed. This strategy allows the system to take advantage of the subframes reserved for each purpose by the Long Term Evolution (LTE) standard, looking for the best joint allocation of the available resources, and results in important improvements in the service throughputThis work was supported in part by the Spanish Ministry of Economy and Competitiveness, National Plan for Scientific Research, Development and Technological Innovation (IN-NPACTO subprogram), LTExtreme project (IPT-2012-0525-430000), and the projects TEC2011-29006-C03-03 (GRE3NSYST) and TEC2014-59255-C3-3-R (ELISA).Publicad

    Joint Strategy for LTE Resource Allocation: Multicast Subgrouping & Unicast Transmissions

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    La ponencia presentada en: XII Jornadas de Ingeniería Telemática (JITEL 2015), celebrada los días 14 al 16 de octubre de 2015, en Palma de Mallorca.Mobile broadband services are growing rapidly in the last few years due to the deployment of Long Term Evolution (LTE) cellular networks. Among them, multicast services can be provided using Evolved Multimedia Broadcast and Multicast Service (eMBMS), available with 3rd Generation Partnership Project (3GPP) release 9, which can deliver broadcast/multicast content using a single-frequency network mode. This means sending the same multimedia content to a mass audience within a specific area. The utilization of the Conventional Multicast Scheme (CMS) approach for multicast resource allocation presents intrinsic inefficiencies, because of the different channel conditions of the users which demand the service. This paper proposes a Joint Multicast Subgrouping and Unicast Transmissions (JMSUT) strategy for resource allocation, which consists of the use of the multicast and the unicast transmissions, by means of the subframes reserved by the LTE standard for each purpose, to deliver a multicast service. The goal of the JMSUT algorithm is to maximize the service throughput whereas it guarantees the fulfillment of the Quality of Service (QoS) requirements of every user. This paper solves the former maximization problem of the joint resource allocation; on the one hand, splitting the multicast resources into different subgroups that transmit the same content with different Modulation and Coding Scheme (MCS), and on the other hand, the users with worst channel conditions are served by means of the unicast transmissions.This work was supported in part by the Spanish Ministry of Economy and Competitiveness, National Plan for Scientific Research, Development and Technological Innovation (IN-NPACTO subprogram), LTExtreme project (IPT-2012-0525- 430000), and the project TEC2014-59255-C3-3-R (ELISA).Publicad

    Estratégia de desenvolvimento local : GAL Terras de Sicó 2020 : uma parceria, um compromisso

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    O presente documento tem como objetivo a proposta de uma Estratégia de Desenvolvimento Local (EDL) para a região de Sicó para o período 2014-2020, e posterior candidatura à 1ª fase de pré-qualificação do Desenvolvimento Local de Base Comunitária (DLBC), na vertente de DLBC rural, conforme o aviso nº 02/2014 de 16-11-2014 do Portugal 2020, tendo como promotor a Terras de Sicó, Associação de Desenvolvimento, cuja abrangência territorial envolve seis concelhos: Alvaiázere, Ansião, Condeixa-a-Nova, Penela, Pombal e Soure (...

    Antioxidant and bioactive compounds of two wild edible mushrooms from Northeast of Portugal: Boletus poliporus and Boletus regius

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    Free radicals are produced in the normal natural metabolism of aerobic cells, mostly in the form of reactive oxygen species (ROS). Maintenance of equilibrium between free radicals production and antioxidant defenses is an essential condition for normal organism functioning [1 ,2]. Although almost all organisms are equipped with antioxidant defense, the antioxidant supplements, or natural products containing bioactive compounds, may be used to help reduce oxidative damage to the human body (3]. Indeed, natural matrices with antioxidant activity, in particular mushrooms, are used to aid the endogenous protective system, increasing interest in the antioxidative role of functional foods or nutraceutical products (2]. The present study describes the antioxidant properties and bioactive compounds of wild edible mushrooms (Boletus porosporus and Boletus regius) collected in Northeast of Portugal (Bragança). The antioxidant properties were assessed through the evaluation of the reducing power, radical scavenging activity and lipid peroxidation inhibition of the samples. The individual profiles of organic acids and phenolic compounds were obtained by high performance liquid chromatography coupled to photodiode array detector (HPLC-POA) and the tocopherols were characterized by HPLC-fluorescence.The Boletus regius sample revealed the best results in all the antioxidant activity assays, with the highest reducing power, highest scavenging activity and highest lipid peroxidation inhibition. Phenolic acids and a related compound (cinnamic acid) were found in both studied species and B. regius revealed the highest content in total phenolic compounds (23.49 mg/1 00 g dw), mainly due to the presence of two possible flavonoids. The highest levels of total tocophero ls were found in B. regius (763.80 j.Jg/1 00 g dw). The highest content in quinic and oxalic acids were found in B. porosporus(1.93 and 0.34 g/1 00 g dw, respectively), while B. regius revealed the highest level of citric acid (3.32 g/1 00 g dw).The results suggest that species of wild mushrooms from Northeast Portugal are a potential source of antioxidants to be explored.FCT and COMPETE/QREN/EU: project PTOC/AGR-ALI/110062/2009, PEst-PTDC/AGRALI/110062/2009 CIMO strategic project and L B. grant (BPD/4609/2008
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