53 research outputs found

    Wireless Power Transfer in Distributed Antenna Systems

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    This paper studies the performance of wireless power transfer in distributed antenna systems (DAS). In particular, the distributed remote radio heads (RRHs), which are conventionally distributed in the network to enhance the performance, are also used to increase the energy harvesting (EH) at the energy-constrained users. Based on this idea, the network area is divided into two zones, namely, A) EH zone and B) Interference zone. The users in the EH zones are guaranteed to harvest sufficient energy from the closed RRH, while the users in the interference zones harvest energy from the surrounding RRHs. A harvest-then-transmit protocol is adopted, where in the power transfer phase the multiple antennas RRHs broadcast energy signals to the users. In the information transmission phase, the users utilize the harvested energy to transmit their signals to the RRHs. In addition, zero-forcing is applied at the RRHs receivers, to mitigate the interference. The system spectral efficiency is evaluated in two different scenarios based on the channel state information (CSI), namely: 1) CSI is unknown at the RRHs; 2) CSI is perfectly known at the RRHs. In contrast to conventional EH-muliple input multiple output (MIMO) systems, performance analysis of EH DAS-MIMO is a challenging problem, because the channels are characterized by non-identical path-loss and EH effects which make the classical analytical methods nontractable. In light of this, new analytical expressions of the ergodic spectral efficiency are derived, and then Monte-Carlo simulations are provided to verify the accuracy of our analysis. The effects of main system parameters on the EH-DAS performance are investigated. The results show that there is an optimal value of the EH time for each users locations that maximizes the system performance. In addition, size of the EH-zone area depends on the required harvested power at the users which is dependent essentially on the target spectral efficiency

    How to Increase Energy Efficiency in Cognitive Radio Networks

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    In this paper, we investigate the achievable energy efficiency of cognitive radio networks where two main modes are of interest, namely, spectrum sharing (known as underlay paradigm) and spectrum sensing (or interweave paradigm). In order to improve the energy efficiency, we formulate a new multiobjective optimization problem that jointly maximizes the ergodic capacity and minimizes the average transmission power of the secondary user network while limiting the average interference power imposed on the primary user receiver. The multiobjective optimization will be solved by first transferring it into a single objective problem (SOP), namely, a power minimization problem, by using the ε-constraint method. The formulated SOP will be solved using two different methods. Specifically, the minimum power allocation at the secondary transmitter in a spectrum sharing fading environment are obtained using the iterative search-based solution and augmented Lagrangian approach for single and multiple secondary links, respectively. The significance of having extra side information and also imperfect side information of cross channels at the secondary transmitter are investigated. The minimum power allocations under perfect and imperfect sensing schemes in interweave cognitive radio networks are also found. Our numerical results provide guidelines for the design of future cognitive radio networks

    Recherche de facteurs de risque immunologiques associés au Lymphome Hodgkinien de l'enfant

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    Le risque de LH est augmenté en cas de déficit immunitaire acquis ou inné. Les déficits immunitaires innés associés à un risque accru de LH, sont les DICV (Déficit Immunitaire Commun Variable), XLP (Syndrome lymphoprolifératif lié au chromosome X) et ALPS (Syndrome lymphoprolifératif Autoimmun). L objectif de notre travail était d évaluer la prévalence de ces déficits immunitaires chez des enfants atteints de LH. Nous avons reçu, 395 prélèvements de patients atteints de LH au diagnostic. L âge médian de la population étudiée est de 13 ans, allant de 3 à 18 ans. Le sex-ratio M/F est de 1.1. Il augmente à 3 au dessous de l âge de 10 ans. Parmi les biopsies (n=84) qui ont été relues, 87% sont de type scléro-nodulaires (SN), 7% à cellularité mixte (CM) et 6% non spécifié. L EBV est détecté in situ dans 23% des cas de LH. Les patients atteints de LH-EBV+ sont significativement plus jeunes que ceux atteints de LH-EBV- (p=3.10-4). Ce sont plus fréquemment des garçons que des filles (63% ; M/F : 1,7) et fréquemment de sous-type CM (40%). Enfin, ils ont une charge virale EBV significativement plus élevée (p=3.10-3) que les enfants qui ont un LH-EBV-.Parmi les 83 premiers enfants analysés, un immunophénotypage approfondi a montré une diminution de la population lymphocytaire par rapport aux témoins et une lymphopénie B fréquente (31 patients sur 83 soit 37% des patients). La lymphopénie B était corrélée aux facteurs pronostiques connus du LH. Dans un cas parmi les 31, une baisse des immunoglobulines a été mise en évidence ce qui est évocateur de DICV. Nous avons montré que dans les autres cas, les lymphopénies se corrigeaient à distance de la maladie. La recherche de profil cytokinique associé à ces lymphopénies (TGF, BAFF, IL-7) n a pas permis de mettre en évidence de mécanisme physiopathologique simple pour expliquer ces lymphopénies. Nous émettons l hypothèse qu elles sont liées à l exposition au contact des cellules tumorales à des signaux favorisant l apopotose.En ce qui concerne la recherche d autres déficits immunitaires innés, aucun cas évocateur de XLP n a été mis en évidence sur la base de la quantification des lymphocytes NKT. Cinq cas parmi les 83 (6%) avaient une expansion de lymphocytes T DN (Lymphocytes TCRab CD4-CD8-) dans le sang périphérique. Des dosages de Fas ligand et d IL-10 plasmatiques ont permis d exclure un ALPS. Au total, nous n avons pas pu affirmer de défaut qualitatif des sous-populations lymphocytaires évoquant les déficits immunitaires de type XLP et ALPS. Seule une lymphopénie B avec baisse des IgG est évocatrice de DICV. Nous avons étendu l analyse à l ensemble des patients (395patients) avec un contrôle à distance du diagnostic pour ceux qui étaient anormaux. Nous avons identifié 4 patients potentiellement atteints de DICV, 1,5%. Parallèlement, nous avons recherché un déficit de la réponse T anti-EBV par cytomètrie de flux et l Elispot. L étude de la réponse T anti-EBV par la cytométrie de flux, a montré une tendance vers une baisse de la production d IL-2 par les CD4 et les CD8 de patients avec une charge virale EBV élevée en réponse à une stimulation par des peptides EBV en présence de lignées autologues. L étude de la réponse T anti EBV par la technique d ELISPOT sur 9 patients n a pas montré globalement de déficit du contrôle de l EBV sauf pour une jeune patiente de 10 ans ayant une charge virale EBV très élevée sans réponse T anti-EBV efficace. Les résultats que nous avons obtenus restent à approfondir, ce qui permettra d enrichir les connaissances actuelles sur cette pathologie.Hodgkin s Lymphoma (HL) is one of the most frequent lymphomas occurring in childhood. In young children, there is a high predominance in boys and frequent association with Epstein-Barr Virus (EBV). Cohort studies have shown that patients affected by several immune deficiency syndromes - e.g. X-linked lymphoproliferative syndrome (XLP), functional deficit of Fas/FasL pathway and common variable immunodeficiency (CVID) - are risk factors of HL. We intend to search for qualitative and quantitative immune deficiencies as susceptibility factors to child's HL in a prospective study related to Euronet PHL C1 protocol. Eighty-three patients at diagnosis of HL have been analysed. Median age of the study population is 13 years, (5-18 years). Gender-ratio M/F is 1.1 with a larger male predominance before the age of 10 (gender-ratio of 3). The search for a defect of NKT population that would be suggesting of XLP was negative in all patients. A moderate expansion of circulating TCRab+ double negative cells (DNT) has been detected in 5 patients. This expansion has been further explored in the hypothesis of a defect of Fas/FasL pathway by plasmatic quantification of Fas ligand and Il-10. This led to the exclusionof the diagnosis of ALPS. An unexpected high frequency of B-cell lymphopenia has been detected in 31 out of 83 patients (37%). Peripheral B cell lymphopenia was associated with the following poor prognostic factors: advanced stages (p1,000 EBV copies per 250000 PBMCs). These cases will be further explored by molecular analyses.Our findings confirm the known epidemiological data of HL now mainly associated to NS subtype in children and adolescents and EBV status in HL at this age. We show that peripheral B cell lymphopenia in paediatric and adolescent HL patients is frequent and associated with poor prognosis factors. We confirm the association between CVID and HL.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

    Physicochemical and bioactive properties of six honey samples from various floral origins from Tunisia

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    The present study was undertaken to determine the physicochemical, biochemical, and antioxidant activities of Tunisian honey samples. All the extracted honey samples appeared to con- form to the European Legislation (EC Directive 2001/110) for all parameters. Mint honey, for instance, possesses significant pH value (p < 0.05), invertase activity, water, and protein contents. In addition, this study demonstrates that the color of the Tunisian honeys is highly variable and ranges from pale yellow to dark brown. The total phenolic, flavonoid and carotenoid contents sig- nificantly vary (p < 0.05). The highest values were found in mint honey, which has a very dark color. Correlations between the analyzed parameters are statistically significant (p < 0.05). The DPPH radical scavenging activity of rosemary honey was determined as lower (p < 0.05) than the other analyzed honey samples. Yet, the highest activity was detected in mint honey. The results suggest that Tunisian honeys could be beneficially used as a functional or nutraceutical substance as they prevent or moderate oxidative stress-related diseases

    Cucurbita maxima Pumpkin Seed Oil: from the Chemical Properties to the Different Extracting Techniques

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    Pumpkin seed oils are rich in bioactive compounds such as tocopherols, sterols, β-carotene, and lutein that have, along with some fatty acids, high nutritional value factors. In addition, it has so far been proven that these compounds have a positive effect on human health. The present study mainly aimed at evaluating the chemical composition and the bioactive compounds of pumpkin (Cucurbita maxima) seed oil of the ‘Béjaoui’ Tunisian cultivar using both cold pressing and solvent extraction methods. The seed oils contained substantial amounts of unsaturated fatty acids, particularly oleic and linoleic acids, with values ranging respectively from 28.19% for cold pressed pumpkin seed oil to 30.56% for pumpkin seed oil extracted by pentane and from 43.86% for pumpkin seed oil extracted by pentane to 46.67% for cold pressed pumpkin seed oil of the total amount of fatty acids. Investigations of different seed oils revealed that extraction techniques had significant effects on the antioxidant activity and the γ-tocopherol. Cold pressed pumpkin seed oil revealed the highest γ-tocopherol content (599.33 mg kg-1) and the highest oxidative stability (3.84 h). However, the chloroform/methanol extracted pumpkin seed oil, which is rich in total phenolics (54.41 mg Gallic Acid Equivalent kg-1), was a more effective scavenger of DPPH radicals (250 µmoles Trolox kg-1) than the poor phenolic pumpkin seed oils extracted by hexane and pentane (110 µmoles Trolox kg-1 vs 100 µmoles Trolox kg-1). Based on its unique seed oil features, cold press extracted pumpkin seed may add great value to product innovation in the industrial, nutritional, cosmetic, and pharmaceutical fields

    Hemi-synthesis of novel (S)-carvone hydrazone from Carum carvi L. essential oils: structural and crystal characterization, targeted bioassays and molecular docking on human protein kinase (CK2) and Epidermal Growth factor Kinase (EGFK)

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    Polyfunctional N,O,O,N-type ligands such as the oxalyl dihydrazide (ODH) may induce formation of mono- , di-, and polynuclear complexes with natural monoterpene ketones, involving ligand bridging and Oxo- bridging. In this context, a novel chiral dihydrazone is designed through hemi-synthesis process by re- acting oxalyldihydrazide (ODH) with ( s )-carvone, the major compound of caraway’s seeds essential oil. The C = N imine bi-condensation is performed without prior isolation of the natural ( s )-carvone and the resulting ( s )-carvone dihydrazone (s-CHD) is structurally characterized by Single-crystal X-ray diffrac- tion, 2D-NMR spectroscopy and chiral LCMS analysis to confirm the formation of a single pure enan- tiomer. In -vitro cell-based assays were conducted on normal fibroblast (L929) using a presBlue (PB) flu- orescence quantification method of cell-viability and by sulforhodamine B calorimetric cytotoxicity as- says to determine the anti-proliferative effect on four human tumoral lines (NCI-H460, Hela, HepG2 and MCF-7) and normal PLP2. Anti-inflammatory assays were determined through NO production by Maurine LPS-stimulated macrophages (RAW 264.7). The ( s )-CHD has no effect on normal cells viability ( > 88%) and PLP2 (GI50 = 326 ug/mL), while a moderate ( ∼55%) to significant ( ∼63%) antigrowth potential was recorded against HepG2, Hela and MCF-7 tumor cell lines, where RAW 264.7 was feebly sensitive. A molecular docking was performed using Autodock vina software on the protein kinase CK2 and Epi- dermal Growth factor Kinase proteins EGFK and the dock scores allowed to identify significant bind- ing affinities (lower G and Ki values) and potential hydrophilic/hydrophobic interactions with ( s )-CHD comparing to the clinical ellipticine as potential ligands. Molecular docking suggests that ( s )-CHD pos- sesses high affinity towards the kinase domain receptors CK2 and EGFR, being able to bind to the ATP region.Thanks are due to the Research Center Scientific and Technical in Analyzes Physico-Chimiques CRAPC Algerian Directorate for research DGRSDT for the financial support. The authors thanks Fundação para a Ciência e a Tecnologia (FC&T, Lisbon) for financial support through projects PTDC/MEC–ONC/29327/2017 and PTDC/EQU-EQU/32473/2017. We are thankful to NOVA University of Lisbon (FCT/UNL) for the financial support from Erasmus + EU international credit mobility 2017–2019. the laboratory for Green Chemistry LAQV-REQUIMTE FCT/MCTES (UID/QUI/50006/2019) is co-financed by the ERDF and the chemistry department for providing the instruments support.info:eu-repo/semantics/publishedVersio

    Systematic review of a RAMSAR wetland and UNESCO biosphere reserve in a climate change hotspot (Ichkeul Lake, Tunisia)

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    Tunisia\u27s Ichkeul Lake is among the most productive ecosystems in the Mediterranean, with a great regional value thanks to its diversity of habitats. It is an important overwintering area for waterfowl species. It is a RAMSAR wetland, a National Park, a UNESCO World Heritage, and a Biosphere Reserve. This review paper provides a broad overview of the climatic, hydraulic, biogeochemical features, bio-resources, and bio-productivity of the Lake. The interconnectivity between the different environmental components of the lake is presented, highlighting the main characteristics of this vital ecosystem. Its ecosystem consists of a permanent lake bordered by temporary marshes. It is connected to the Mediterranean Sea via Bizerte Lagoon under a typical semi-arid to sub-humid bio-climate with wet and dry seasons. The winter rainfall fills up the rivers and lake with freshwater that overflows into the Tinja River. In summer, high evaporation reduces the water level and allows seawater to enter the wetland from Bizerte Lagoon. The ecosystem is threatened by pollution, the damming of its main rivers, and climate change. The unsustainable water management has resulted in fundamental environmental modifications, as evidenced by the large variation in the salinity, water level, productivity of water plants, and the decline in venue and stop-overs of waterbirds. The current situation is a warning that indicates a general perturbation of the resources of this particular site and of Tunisian wetlands in general, especially that the Mediterranean region has been designated as a climate change hotspot. Accurate hydrological management is needed to boost the physical functioning of the ecosystem, and to gain deeper knowledge of the different phases of the water cycle and its relationship to other long-term environmental cycles for sustainable water management strategies in the most water-scarce region in the world

    Comparative Study of the Long-Term Impact of the COVID-19 Pandemic on Mental Health and Nutritional Practices Among International Elite and Sub-Elite Athletes: A Sample of 1420 Participants from 14 Countries

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    Background Although several studies have shown that the Coronavirus Disease 2019 (COVID-19) lockdown has had negative impacts on mental health and eating behaviors among the general population and athletes, few studies have examined the long-term effects on elite and sub-elite athletes. The present study aimed to investigate the long-term impact of COVID-19 lockdown on mental health and eating behaviors in elite versus sub-elite athletes two years into the pandemic. A cross-sectional comparative study was conducted between March and April 2022, involving athletes from 14 countries, using a convenient non-probabilistic and snowball sampling method. A total of 1420 athletes (24.5 ± 7.9 years old, 569 elites, 35% women, and 851 sub-elites, 45% women) completed an online survey-based questionnaire. The questionnaire included a sociodemographic survey, information about the COVID-19 pandemic, the Depression, Anxiety and Stress Scale—21 Items (DASS-21) for mental health assessment, and the Rapid Eating Assessment for Participants (REAP-S) for assessing eating behavior. Results The results showed that compared to sub-elite athletes, elite athletes had lower scores on the DASS-21 (p = .001) and its subscales of depression (p = .003), anxiety (p = .007), and stress (p < .001), as well as a lower REAP-S score indicating lower diet quality (p = .013). Conclusion In conclusion, two years into the pandemic, elite athletes were likelier to have better mental health profiles than sub-elite athletes but surprisingly had lower diet quality. Key Points Elite athletes had better mental health profiles compared to sub-elite athletes, with lower levels of depression, anxiety, and stress. Elite athletes reported greater psychological support and perceived themselves as more financially secure during the pandemic than sub-elite athletes do. Elite athletes were more likely to have poor eating habits compared to sub-elite athletes

    Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

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    First published: 16 February 202

    Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

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    Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe
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