835 research outputs found

    Analysis of Impact in the Wi-Fi QoS of the EDCA Parameters

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    With the continuing development of the wireless technologies (Wi-Fi, 3G, 4G, WiMax and Bluethooth), the study of wireless multimedia transmissions has gained lately more attention. For example, the expectations of the company leaders on the growth of Wi-Fi video traffic has updated the lines of research on the standard IEEE 802.11e introduced to provide QoS (Quality of Service) to WLAN (Wireless LAN ) networks. In this paper we updated with greater accuracy, using other resources and the experience gained since the emergence of the standard, the work carried out previously on the quantitative impact of each EDCA (Enhanced Distributed Channel Access) parameter on the overall performance of the mechanisms MAC. A quantitative analysis of the optimizations that can be achieved has been performed by simulation. We use a node model EDCA 802.11e with the tool Möbius of the University of Illinois, which supports an extension of SPN (Stochastic Petri Networks), known as HSAN (Hierarchical Stochastic Activity Networks), what favors the contrast with other tools or mathematical resources. We use a realistic scenario formed by Wi-Fi stations with the capacity to transmit voice, video and best effort traffic. The results show that the default setting of EDCA parameters is not optimal, and that with an appropriate selection, very significant improvements can be obtained. Keywords: QoS, WLAN, EDCA 802.11e, MAC Parameters, Analysis of traffi

    Moral Hazard Versus Liquidity and the Optimal Timing of Unemployment Benefits

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    We develop a novel way of identifying the liquidity and moral hazard effects of unemployment insurance exclusively from how job-finding rates respond to unemployment benefits that vary over an unemployment spell. We derive a sufficient statistics formula for the dynamically optimal level of unemployment benefits based on these two effects. Using a regression kink design (RKD) that simultaneously exploits two kinks in the schedule of unemployment benefits, we apply our method to Spain for the years 1992-2012 and find that moral hazard effects dominated liquidity effects, suggesting that Spanish unemployment benefits exceeded the optimal level in that periodJ.I. García-Pérez gratefully acknowledges financial support by research projects SEJ-1512/ECON, P18-RT-2135 (Fondo Europeo de Desarrollo Regional, Junta de Andalucía), PID2019-104452RB-I00 and ECO2015-65408-R (MINECO/FEDER), and I. Reggio by the Spanish Ministerio de Ciencia, Innovación y Universidades (Grant PID2019107916GB-I00

    The end of the demographic dividend in Latin America: challenges for economic and social policies

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    Artículo de revistaPopulation ageing is a major global challenge. The Latin American economies have a younger population structure than other emerging and advanced economies, which has allowed them to enjoy the so-called demographic dividend (a favourable working age/non-working age population ratio). However, according to the latest demographic projections of the United Nations (UN), it is estimated that in 2020 the Latin American population pyramid will resemble that of the advanced economies in 1990 and that, by around 2050, both groups will have similar population profiles. This article documents the current demographic trends in Latin America and discusses the main related challenges, in particular, those arising from the adaptation of social welfare systems to population ageing

    Bioactive compounds, antioxidant and antimicrobial activity of propolis extracts during In vitro digestion

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    The objective of this research was to determine the content of total phenols, total flavonoids, and the antioxidant and antimicrobial activity of the ethanolic extracts of propolis obtained by two methodologies during in vitro digestion. Ethanolic extracts of propolis were obtained by ultrasound and maceration and the yield and content of the bioactive compounds, as well as their antimicrobial and antioxidant activity, were evaluated. Yields higher than those reported in other investigations (71.6%) were obtained. The highest content of phenols and flavonoids in the ethanolic extracts was 34,406.6 mg GAE/100 g in propolis from San Pedro, obtained by maceration (SP M), and 19,523.2 mg QE/100 g in propolis from Teotitlán, obtained by ultrasound (TU), respectively, being higher than what is established in Mexican regulations. The antioxidant and antimicrobial activity of the extracts was not affected by the method of obtaining. At the end of the in vitro digestion there was an 80% loss of the phenolic content and a 90% loss of the flavonoid content. Therefore, antioxidant activity was affected. On the other hand, ultrasound improves the obtaining of bioactive compounds. In vitro digestion decreases the content of bioactive compounds; therefore, their functional properties are affected. Thus, it is important to consider technologies that allow extracts to be protected from in vitro digestion conditions.info:eu-repo/semantics/publishedVersio

    Update Review and Clinical Presentation in Congenital Insensitivity to Pain and Anhidrosis

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    Introduction. Congenital insensitivity to pain and anhidrosis (CIPA) or hereditary sensory and autonomic neuropathy type IV is an extremely rare syndrome. Three clinical findings define the syndrome: insensitivity to pain, impossibility to sweat, and mental retardation. This pathology is caused by a genetic mutation in the NTRK1 gene, which encodes a tyrosine receptor (TrkA) for nerve growth factor (NGF). Methods. The consultation of a child female in our center with CIPA and a tibia fracture in pseudoarthrosis encouraged us to carefully review literature and examine the therapeutic possibilities. A thorough review of literature published in Pubmed was done about CIPA and other connected medical issues mentioned in the paper. Conclusions. The therapeutic approach of CIPA remains unclear. The preventive approach remains the only possible treatment of CIPA. We propose two new important concepts in the therapeutic approach for these patients: (1) early surgical treatment for long bone fractures to prevent pseudoarthrosis and to allow early weight bearing, decreasing the risk of further osteopenia, and (2) bisphosphonates to avoid the progression of osteopenia and to reduce the number of consecutive fractures

    Putative antimicrobial peptides of the posterior salivary glands from the cephalopod octopus vulgaris revealed by exploring a composite protein database

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    Cephalopods, successful predators, can use a mixture of substances to subdue their prey, becoming interesting sources of bioactive compounds. In addition to neurotoxins and enzymes, the presence of antimicrobial compounds has been reported. Recently, the transcriptome and the whole proteome of the Octopus vulgaris salivary apparatus were released, but the role of some compounds—e.g., histones, antimicrobial peptides (AMPs), and toxins—remains unclear. Herein, we profiled the proteome of the posterior salivary glands (PSGs) of O. vulgaris using two sample preparation protocols combined with a shotgun-proteomics approach. Protein identification was performed against a composite database comprising data from the UniProtKB, all transcriptomes available from the cephalopods’ PSGs, and a comprehensive non-redundant AMPs database. Out of the 10,075 proteins clustered in 1868 protein groups, 90 clusters corresponded to venom protein toxin families. Additionally, we detected putative AMPs clustered with histones previously found as abundant proteins in the saliva of O. vulgaris. Some of these histones, such as H2A and H2B, are involved in systemic inflammatory responses and their antimicrobial effects have been demonstrated. These results not only confirm the production of enzymes and toxins by the O. vulgaris PSGs but also suggest their involvement in the first line of defense against microbes.AA was partially supported by the Strategic Funding UIDB/04423/2020 and UIDP/04423/2020 through national funds provided by FCT and the European Regional Development Fund (ERDF) in the framework of the program PT2020, by the European Structural and Investment Funds (ESIF) through the Competitiveness and Internationalization Operational Progra-COMPETE 2020 and by National Funds through the FCT under the project PTDC/CTA-AMB/31774/2017 (POCI-01-0145-FEDER/031774/2017)

    Incidencia de microorganismos mesófilos en la producción del agua de bebida envasada

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    With the purpose, of determining the likely incidence of mesophilic microorganisms on bottled drinking-water (BDW), the most relevant factors involved in the water production were analyzed. In order to determine the quality, water was stored in several different containers (polycarbonate, glass, high-density polyethylene (HDP), low-density polyethylene (LDP), and polyethylene-coextruded polypropilene (PCP) containers), and subsequently total counts were analysed for mesophilic microorganisms and the most likely number for total coliforms and Pseudomona aeruginosa. The best results were achieved by using glass-containers. Subsequently the treatment of water (chlorination-ozonisation) was compared by using two types of containers (LDP and PCP) so as to determine which material and treatment best kept best the organoleptic and physicochemical features, as well as causing the lowest incidence of mesophilic microorganism during the span of product storage. The most adequate container turned out to be that made from 2.5 gauge PCP with 0.6 ppm chlorine treatment It was also concluded that bacterial growth was more an additional by-product of storage and typeof container since our sampling of the production methods showed that at al1 times the water was drinkable. Lastly, a tasting panel was held where 80% of the tasters selected chose the PCP.Con el fin de determinar una posible incidencia de microorganismos mesófilos en la producción del agua de bebida envasada, se analizaron los factores más importantes implicados en la producción. Para determinar la calidad del agua, se almacenó en diferentes tipos de envases (policarbonato, vidrio, polietileno de alta densidad (PAD), polietileno de baja densidad (PBD) y polipropileno coextruído con polietileno (PCP), y posteriormente se realizaron recuentos totales para microorganismos mesófilos y número más probable paracoliformes totales y Pseudomona aeruginosa obteniéndose menores recuentos en el agua envasada  en vidrio. Posteriormente, se compararon los tratamientos de descontaminación del agua (cloraciónozonización) utilizando dos tipos de envase (PBD y PCP), para determinar el material y tratamiento que conservan mejor las características organolépticas-fisicoquimicas y la menor incidencia de microorganismos mesófilos durante el tiempo de almacenamiento del producto. El envase más adecuado es el de PCP de calibre 2,5 con el tratamiento de cloro 0,6 pm; también se demostró que el crecimiento bacteria no fue un producto más del almacenamiento y el tipo de envase, ya que al realizar el muestre0 de los sistemas de producción, el agua fue siempre potable. Finalmente, se realizó un panel de saboreo, obteniéndose una preferencia del 80% de los encuestados, hacia el envase de PCP con el tratamiento de cloro

    Lepton Number Violation from Colored States at the LHC

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    The possibility to search for lepton number violating signals at the Large Hadron Collider (LHC) in the colored seesaw scenario is investigated. In this context the fields that generate neutrino masses at the one-loop level are scalar and Majorana fermionic color-octets of SU(3). Due to the QCD strong interaction these states may be produced at the LHC with a favorable rate. We study the production mechanisms and decays relevant to search for lepton number violation signals in the channels with same-sign dileptons. In the simplest case when the two fermionic color-octets are degenerate in mass, one could use their decays to distinguish between the neutrino spectra. We find that for fermionic octets with mass up to about 1 TeV the number of same-sign dilepton events is larger than the standard model background indicating a promising signal for new physics.Comment: minor corrections, added reference

    Diagnosis of Transient/Latent HPV Infections - A Point of View!

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    © 2018 IMSS Diagnosis of transient/latent HPV infections requires a rethinking of ideas concerning the host virus relationship. With this in mind, we address several concepts, such as mutualism and commensalism, to understand better the different stages of development, in addition to briefly covering current methods of detection. We suggest analyzing molecules related to the innate immune response for earlier diagnosis
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