2,938 research outputs found

    Effects of highly active antiretroviral therapy with nelfinavir in vertically HIV-1 infected children: 3 years of follow-up. Long-term response to nelfinavir in children

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    BACKGROUND: Antiretroviral treatment (ART) in children has special features and consequently, results obtained from clinical trials with antiretroviral drugs in adults may not be representative of children. Nelfinavir (NFV) is an HIV-1 Protease Inhibitor (PI) which has become as one of the first choices of PI for ART in children. We studied during a 3-year follow-up period the effects of highly active antiretroviral therapy with nelfinavir in vertically HIV-1 infected children. METHODS: Forty-two vertically HIV-infected children on HAART with NFV were involved in a multicentre prospective study. The children were monitored at least every 3 months with physical examinations, and blood sample collection to measure viral load (VL) and CD4+ cell count. We performed a logistic regression analysis to determinate the odds ratio of baseline characteristics on therapeutic failure. RESULTS: Very important increase in CD4+ was observed and VL decreased quickly and it remained low during the follow-up study. Children with CD4+ <25% at baseline achieved CD4+ >25% at 9 months of follow-up. HIV-infected children who achieved undetectable viral load (uVL) were less than 40% in each visit during follow-up. Nevertheless, HIV-infected children with VL >5000 copies/ml were less than 50% during the follow-up study. Only baseline VL was an important factor to predict VL control during follow-up. Virological failure at defined end-point was confirmed in 30/42 patients. Along the whole of follow-up, 16/42 children stopped HAART with NFV. Baseline characteristics were not associated with therapeutic change. CONCLUSION: NFV is a safe drug with a good profile and able to achieve an adequate response in children

    The Hubble Constant

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    I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H0H_0 values of around 72-74km/s/Mpc , with typical errors of 2-3km/s/Mpc. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68km/s/Mpc and typical errors of 1-2km/s/Mpc. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.Comment: Extensively revised and updated since the 2007 version: accepted by Living Reviews in Relativity as a major (2014) update of LRR 10, 4, 200

    Comparative LCA of concrete with recycled aggregates: a circular economy mindset in Europe

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    [EN] Purpose Construction and demolition waste (C&DW) is the largest waste stream in the European Union (EU) and all over the world. Proper management of C&DW and recycled materialsÂżincluding the correct handling of hazardous wasteÂżcan have major benefits in terms of sustainability and the quality of life. The Waste Framework Directive 2008/98/EC aims to have 70% of C&DW recycled by 2020. However, except for a few EU countries, only about 50% of C&DW is currently being recycled. In the present research, the environmental impact of concrete with recycled aggregates and with geopolymer mixtures is analysed. The aim of the present research is to propose a comparative LCA of concrete with recycled aggregates in the context of European politics. Methods Life cycle assessment (LCA) methodology is applied using Simapro© software. A cradle to grave analysis is carried out. The results are analysed based on the database Ecoinvent 3.3 and Impact 2002+. Results Results show that the concrete with 25% recycled aggregates is the best solution from an environmental point of view. Furthermore, geopolymer mixtures could be a valid alternative to reduce the phenomenon of Âżglobal warmingÂż; however, the production of sodium silicate and sodium hydroxide has a great environmental impact. Conclusions A possible future implementation of the present study is certainly to carry out an overall assessment and to determine the most cost-effective option among the different competing alternatives through the life cycle cost analysis.Colangelo, F.; GĂłmez-Navarro, T.; Farina, I.; Petrillo, A. (2020). Comparative LCA of concrete with recycled aggregates: a circular economy mindset in Europe. International Journal of Life Cycle Assessment. 25(9):1790-1804. https://doi.org/10.1007/s11367-020-01798-6S17901804259Akhtar A, Sarmah (2018) Construction and demolition waste generation and properties of recycled aggregate concrete: a global perspective. J Cleaner Prod 186:262–281Bare JC, Hofstetter P, Penningtonne DW, Helias A, de Haes U (2000) Midpoints versus endpoints: the sacrifices and benefits. Int J Life Cycle Assess 5(6):319–326Blengini GA, Garbarino E (2010) Resources and waste management in Turin (Italy): the role of recycled aggregates in the sustainable supply mix. J Clean Prod 18(10–11):1021–1030Blengini GA, Garbarino E, Ć olar S, Shields DJ, HĂĄmor T, Vinai R, Agioutantis Z (2012) Life cycle assessment guidelines for the sustainable production and recycling of aggregates: the sustainable aggregates resource management project (SARMa). J Clean Prod 27:177–181Blengini GA, Garbarino E, Bevilacqua P (2017) Sustainability and integration between mineral resources and C&DW management: overview of key issues towards a resource-efficient Europe. Env Eng Man J 16(2):493–502Borghi G, Pantini S, Rigamonti L (2018) Life cycle assessment of non-hazardous construction and demolition waste (CDW) management in Lombardy region (Italy). J Clean Prod 184:815–825Braga AM, Silvestre JD, de Brito J (2017) Compared environmental and economic impact from cradle to gate of concrete with natural and recycled coarse aggregates. J Clean Prod 162:529–543Chen C, Habert G, Bouzidi Y, Jullien A, Ventura A (2010) LCA allocation procedure used as an incitative method for waste recycling: an application to mineral additions in concrete. Res Con Rec 54(12):1231–1240Chen Z, Gu H, Bergman RD, Liang S (2020) Comparative life-cycle assessment of a high-rise mass timber building with an equivalent reinforced concrete alternative using the Athena impact estimator for buildings. Sustainability (Switzerland) 12(11):4708Colangelo F, Cioffi R (2017) Mechanical properties and durability of mortar containing fine fraction of demolition wastes produced by selective demolition in South Italy. Comp Part B: Eng 115:43–50Colangelo F, Petrillo A, Cioffi R, Borrelli C, Forcina A (2018a) Life cycle assessment of recycled concretes: a case study in southern Italy. Sci Total Env 615:1506–1517Colangelo F, Forcina A, Farina I, Petrillo A (2018b) Life cycle assessment (LCA) of different kinds of concrete containing waste for sustainable construction. Buildings 8(5):70Colangelo F, Navarro TG, Petrillo A, Farina I, Cioffi R (2020) Life-cycle impact of concrete with recycled materials. Encyclopedia of Renewable and Sustainable Materials, Volume 5(2020):414–421COM (2012) 433, COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT AND THE COUNCIL Strategy for the sustainable competitiveness of the construction sector and its enterprises, http://eur-lex.europa.eu/procedure/EN/201859, Brussels, 31.7.2012, COM(2012) 433 finalCOM (2014) 445, COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT AND THE COUNCIL, http://ec.europa.eu/environment/eussd/pdf/SustainableBuildingsCommunication.pdf, Brussels, 1.7.2014 COM(2014) 445 finalDavidovits J (2018) Geopolymers based on natural and synthetic metakaolin a critical review. Ceramic Eng Science Proc 38(3):201–214Di Maria A, Eyckmans J, Van Acker K (2018) Downcycling versus recycling of construction and demolition waste: combining LCA and LCC to support sustainable policy making. Waste Man 75:3–21Directive 2008/98/EC on waste (Waste Framework Directive), http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008L0098EN 1992-1-1:(2004) Eurocode 2: Design of concrete structures - Part 1–1: General rules and rules for buildingsEstanqueiro B, Dinis Silvestre J, de Brito J, Duarte Pinheiro M (2018) Environmental life cycle assessment of coarse natural and recycled aggregates for concrete. Eur J Env Civ Eng 22(4):429–449Etxeberria M, VĂĄzquez E, MarĂ­ A, Barra M (2007) Influence of amount of recycled coarse aggregates and production process on properties of recycled aggregate concrete. Cem Conc Res 37(5):735–742EU construction & demolition waste management protocol (2016) BrusselsGĂĄlvez-Martos J-L, Styles D, Schoenberger H, Zeschmar-Lahl B (2018) Construction and demolition waste best management practice in Europe. Res Con Rec 136:166–178Gluth, G.J.G., Arbi, K., Bernal, S.A., Bondar, D., Castel, A., Chithiraputhiran, S., Dehghan, A., Dombrowski-Daube, K., Dubey, A., Ducman, V., Peterson, K., Pipilikaki, P., Valcke, S.L.A., Ye, G., Hajimohammadi, A., van Deventer, J.S.J., 2017. Characterisation of one-part geopolymer binders made from fly ash. Waste Biom Val, 8(1), pp. 225–233Gomes R, Silvestre JD, de Brito J (2020) Environmental, economic and energy life cycle assessment “from cradle to cradle” (3E-C2C) of flat roofs. Journal of Building Engineering 32:101436ISO 14040 (2006) Environmental management life cycle assessment. Principles and Framework. ISO, GenevaISO 14044 (2006) Environmental management. Life cycle assessment. Requirements and Guidelines. ISO, GenevaJafary Nasab T, Monavari SM, Jozi SA, Majedi H (2020) Assessment of carbon footprint in the construction phase of high-rise constructions in Tehran. Int J Environ Sci Technol 17(6):3153–3164Jolliet O, Margni M, Charles R, Humbert S, Payet J, Rebitzer G, Rosenbaum R (2003) Impact 2002+: a new life cycle impact assessment methodology. Int J Life Cycle Assess 8(6):324–333Khan MW, Ali Y, De Felice F, Salman A, Petrillo A (2019) Impact of brick kilns industry on environment and human health in Pakistan. Sci Total Environ 678:383–389Knoeri C, SanyĂ©-Mengual E, Althaus H-J (2013) Comparative LCA of recycled and conventional concrete for structural applications. Int J Life Cycle Assess 18(5):909–918Lu W, Yan H (2011) A framework for understanding waste management studies in construction. Waste Man 31:1252–1260Marinković S, Radonjanin V, MaleĆĄev M, Ignjatović I (2010) Comparative environmental assessment of natural and recycled aggregate concrete. Waste Man 30(11):2255–2264Mercante IT, Bovea MD, Ibåñez-ForĂ©s V, Arena AP (2012) Life cycle assessment of construction and demolition waste management systems: a Spanish case study. Int J Life Cycle Assess 17(2):232–241Pantini S, Giurato M, Rigamonti L (2019) A LCA study to investigate resource-efficient strategies for managing post-consumer gypsum waste in Lombardy region (Italy). Res Con Rec 147:157–168Petrillo A, Cioffi R, De Felice F, Colangelo F, Borrelli C (2016) An environmental evaluation: a comparison between geopolymer and OPC concrete paving blocks manufacturing process in Italy. Env Prog Sus Energy 35(6):1699–1708Provis JL (2017) Alkali-activated cementitious materials and concretes - steps towards standardization, American Concrete Inst, ACI Special Publication 2017-January (SP 320), pp. 444-448Sayagh S, Ventura A, Hoang T, François D (2010) Sensitivity of the LCA allocation procedure for BFS recycled into pavement structures. Res cons rec 54(6):348–358Tangtinthai N, Heidrich O, Manning DAC (2019) Role of policy in managing mined resources for construction in Europe and emerging economies. J Env Man 236:613–621ToĆĄić N, Marinković S, DaĆĄić T, Stanić M (2015) Multicriteria optimization of natural and recycled aggregate concrete for structural use. J Clean Prod 87(1):766–776Van den Heede P, De Belie N (2012) Environmental impact and life cycle assessment (LCA) of traditional and ‘green’ concretes: literature review and theoretical calculations. Cem Conc Comp 34(4):431–442Vossberg C, Mason-Jones K, Cohen B (2014) An energetic life cycle assessment of C&D waste and container glass recycling in Cape Town, South Africa. Res Con Rec 88:39–49Walling SA, Notman S, Watts P, Govan N, Provis JL (2019) Portland cement based immobilization/destruction of chemical weapon agent degradation products. Industrial Eng Chemistry Res 58(24):10383–10393Wu H, Zuo J, Yuan H, Zillante G, Wang J (2019) A review of performance assessment methods for construction and demolition waste management. Res Cons Recycling 150:104407Zhang C, Hu M, Dong L, Gebremariam A, Mirand-Xicotencatl B, Di Maio F, Tukker A (2019) Eco-efficiency assessment of technological innovations in high-grade concrete recycling. Res Cons Recycling 149:649–66

    LEMUR: Large European Module for solar Ultraviolet Research. European contribution to JAXA's Solar-C mission

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    Understanding the solar outer atmosphere requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1" and 0.3"), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 17 and 127 nm. The LEMUR slit covers 280" on the Sun with 0.14" per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km/s or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission.Comment: 35 pages, 14 figures. To appear on Experimental Astronom

    Nutritional profile and obesity: results from a random‑sample population‑based study in Córdoba, Argentina

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    Introduction Obesity is a chronic, heterogeneous, multifactorial disease, which has sharply increased in prevalence in both developed and developing countries. This study aimed to estimate the prevalence of obesity and to identify socio-demographic risk factors associated with it, with special emphasis on diet. Methods Nutritional status, demographic characteristics, lifestyle habits, and food consumption patterns derived from a Food Frequency Questionnaire were investigated. Exhaustive exploratory analyses were performed in order to describe dietary patterns, and logistic regression models were used for odds ratio estimation. Results The study included 4328 subjects, over 18 years old and resident in Cordoba city. The prevalence of overweight and obesity was 34 and 17 %, respectively, with 60 % in men and 45 % in women of BMI ≄ 25. Obesity risk factors were high intake of sodium, refined grains, starchy vegetables, and snacks. A lower risk of overweight and obesity was associated with an adequate, moderate intake of meats, eggs, alcoholic beverages, sugar and sweets, milk, yogurt, and pulses. Conclusions A high intake of snacks, refined grains, starchy vegetables and sodium and low intake of yogurt, milk, pulses, and whole grains seem to be associated with the emergence and high prevalence of obesity in Cordoba, Argentina.publishedVersionFil: Aballay, Laura Rosana. Universidad Nacional de CĂłrdoba. Facultad de Ciencias MĂ©dicas. Escuela de NutriciĂłn. EstadĂ­stica y BioestadĂ­stica; ArgentinaFil: Aballay, Laura Rosana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: De la Quintana, Ana Gabriela. Universidad Nacional de CĂłrdoba. Facultad de Ciencias MĂ©dicas. Escuela de NutriciĂłn; Argentina.Fil: DĂ­az, MarĂ­a del Pilar. Universidad Nacional de CĂłrdoba. Facultad de Ciencias MĂ©dicas. Escuela de NutriciĂłn. EstadĂ­stica y BioestadĂ­stica; Argentina.Fil: DĂ­az, MarĂ­a del Pilar. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: Osella, Alberto R. Hospital Saverio de Bellis. Laboratorio de Epidemiologia y BioestadĂ­stica; Italia

    Cluster Lenses

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    Clusters of galaxies are the most recently assembled, massive, bound structures in the Universe. As predicted by General Relativity, given their masses, clusters strongly deform space-time in their vicinity. Clusters act as some of the most powerful gravitational lenses in the Universe. Light rays traversing through clusters from distant sources are hence deflected, and the resulting images of these distant objects therefore appear distorted and magnified. Lensing by clusters occurs in two regimes, each with unique observational signatures. The strong lensing regime is characterized by effects readily seen by eye, namely, the production of giant arcs, multiple-images, and arclets. The weak lensing regime is characterized by small deformations in the shapes of background galaxies only detectable statistically. Cluster lenses have been exploited successfully to address several important current questions in cosmology: (i) the study of the lens(es) - understanding cluster mass distributions and issues pertaining to cluster formation and evolution, as well as constraining the nature of dark matter; (ii) the study of the lensed objects - probing the properties of the background lensed galaxy population - which is statistically at higher redshifts and of lower intrinsic luminosity thus enabling the probing of galaxy formation at the earliest times right up to the Dark Ages; and (iii) the study of the geometry of the Universe - as the strength of lensing depends on the ratios of angular diameter distances between the lens, source and observer, lens deflections are sensitive to the value of cosmological parameters and offer a powerful geometric tool to probe Dark Energy. In this review, we present the basics of cluster lensing and provide a current status report of the field.Comment: About 120 pages - Published in Open Access at: http://www.springerlink.com/content/j183018170485723/ . arXiv admin note: text overlap with arXiv:astro-ph/0504478 and arXiv:1003.3674 by other author

    The Formation of the First Massive Black Holes

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    Supermassive black holes (SMBHs) are common in local galactic nuclei, and SMBHs as massive as several billion solar masses already exist at redshift z=6. These earliest SMBHs may grow by the combination of radiation-pressure-limited accretion and mergers of stellar-mass seed BHs, left behind by the first generation of metal-free stars, or may be formed by more rapid direct collapse of gas in rare special environments where dense gas can accumulate without first fragmenting into stars. This chapter offers a review of these two competing scenarios, as well as some more exotic alternative ideas. It also briefly discusses how the different models may be distinguished in the future by observations with JWST, (e)LISA and other instruments.Comment: 47 pages with 306 references; this review is a chapter in "The First Galaxies - Theoretical Predictions and Observational Clues", Springer Astrophysics and Space Science Library, Eds. T. Wiklind, V. Bromm & B. Mobasher, in pres

    The Formation and Evolution of the First Massive Black Holes

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    The first massive astrophysical black holes likely formed at high redshifts (z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations. These black holes grow by mergers and gas accretion, evolve into the population of bright quasars observed at lower redshifts, and eventually leave the supermassive black hole remnants that are ubiquitous at the centers of galaxies in the nearby universe. The astrophysical processes responsible for the formation of the earliest seed black holes are poorly understood. The purpose of this review is threefold: (1) to describe theoretical expectations for the formation and growth of the earliest black holes within the general paradigm of hierarchical cold dark matter cosmologies, (2) to summarize several relevant recent observations that have implications for the formation of the earliest black holes, and (3) to look into the future and assess the power of forthcoming observations to probe the physics of the first active galactic nuclei.Comment: 39 pages, review for "Supermassive Black Holes in the Distant Universe", Ed. A. J. Barger, Kluwer Academic Publisher

    MRI lesions in the sacroiliac joints of patients with spondyloarthritis: an update of definitions and validation by the ASAS MRI working group

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    OBJECTIVES: The Assessment of SpondyloArthritis international Society (ASAS) MRI working group (WG) was convened to generate a consensus update on standardised definitions for MRI lesions in the sacroiliac joint (SIJ) of patients with spondyloarthritis (SpA), and to conduct preliminary validation. // METHODS: The literature pertaining to these MRI lesion definitions was discussed at three meetings of the group. 25 investigators (20 rheumatologists, 5 radiologists) determined which definitions should be retained or required revision, and which required a new definition. Lesion definitions were assessed in a multi-reader validation exercise using 278 MRI scans from the ASAS classification cohort by global assessment (lesion present/absent) and detailed scoring (inflammation and structural). Reliability of detection of lesions was analysed using kappa statistics and the intraclass correlation coefficient (ICC). // RESULTS: No revisions were made to the current ASAS definition of a positive SIJ MRI or definitions for subchondral inflammation and sclerosis. The following definitions were revised: capsulitis, enthesitis, fat lesion and erosion. New definitions were developed for joint space enhancement, joint space fluid, fat metaplasia in an erosion cavity, ankylosis and bone bud. The most frequently detected structural lesion, erosion, was detected almost as reliably as subchondral inflammation (Îșappa/ICC:0.61/0.54 and 0.60/0.83) . Fat metaplasia in an erosion cavity and ankylosis were also reliably detected despite their low frequency (Îșappa/ICC:0.50/0.37 and 0.58/0.97). // CONCLUSION: The ASAS-MRI WG concluded that several definitions required revision and some new definitions were necessary. Multi-reader validation demonstrated substantial reliability for the most frequently detected lesions and comparable reliability between active and structural lesions
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