297 research outputs found

    Unconventional Oil and Gas Development: Evaluation of selected hydrocarbons in the ambient air of three basins in the United States by means of diffusive sampling measurements

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    The impact of emissions associated with the extraction of crude oil and natural gas upon air quality in the United States (US) is widely recognised to have an impact on climate change, human health and ground-level ozone formation. A number of measurement approaches are being applied to evaluate the environmental impact of the oil and gas (O&G) sector, including satellite, airborne and ground-based platforms. Measurement based studies, in particular those that estimate flux rates, are critical for the validation of emission inventories that often under-report actual emissions of methane and volatile organic compounds (VOC) from the O&G sector. On-going research projects in the US are investigating the consistency of emission rates from O&G emission sources associated with extraction, transmission and distribution activities. The leakage rates of methane, as related to production levels, in the US for O&G developments varies from less than 1% (e.g. Upper Green River Basin, Wyoming) to over 6% (Uintah Basin, Utah). European research and policy approaches can learn from efforts in the US that are improving the accuracy of reporting emissions from O&G sources, enhancing our understanding of air quality impacts, and reducing emissions through regulatory controls. The Joint Research Centre (JRC) of the European Commission performed a diffusive sampling project, with the collaboration of the University of Wyoming, in conjunction with the SONGNEX (Studying the Atmospheric Effects of Changing Energy Use in the US at the Nexus of Air Quality and Climate Change) project led by the US National Oceanic and Atmospheric Administration. The SONGNEX project is an airborne measurement campaign supported by a number of associated ground based studies. The applicability of the Pocket Diffusive (PoD) sampler, for measurement of VOC (C4-C10), heavy hydrocarbons and volatile polycyclic aromatic hydrocarbons (PAHs) in areas heavily influenced by O&G development, is evaluated. Three sampling surveys were performed to assess three basins (Upper Green River, Uintah and North Platte) characterised by different management regimes, meteorology and hydrocarbon products. This first extensive field deployment of the PoD sampler demonstrates the effectiveness of the sampler for time-integrated measurements of targeted pollutants over wide spatial areas. The ambient air at these basins reveal different compositional profiles of hydrocarbons (C4-C10). Analysis of aromatics supports a finding of relatively elevated levels in the Pinedale Anticline (Upper Green River). From an evaluation of the behaviour of alkanes, it is evident that there is a relatively high leakage rate in the Uintah Basin. Heavy hydrocarbons (C11-C22) and PAHs are measured at relatively low levels. Despite low concentrations, analysis of these compounds improves the accuracy of source identification. A comparison of ground based PoD data and airborne SONGNEX data showed good agreement for commonly reported VOCs. The utility of the PoD sampler for analysis of emission sources was enhanced with reporting of a wide range of compounds. Spatial Positive Matrix Factorization analysis showed the possibility of using PoD samplers for differentiating emission sources, characterizing different areas and estimating the relative contribution of different emission sources.JRC.C.5-Air and Climat

    Determining efficacy of monitoring devices on ceramic bond to resin composite

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    Objectives: This paper aims to assess the effectiveness of 3D nanoroughness and 2D microroughness evaluations, by their correlation with contact angle measurements and shear bond strength test, in order to evaluate the effect of two different acids conditioning on the bonding efficacy of a leucite-based glass-ceramic to a composite resin. Study Design: Ceramic (IPS Empress) blocks were treated as follows: 1) no treatment, 2) 37% phosphoric acid (H 3 PO 4 ), 15 s, 3) 9% hydrofluoric acid (HF), 5 min. Micro- and nano-roughness were assessed with a profilometer and by means of an atomic force microscopy (AFM). Water contact angle (CA) measurements were determined to assess wettability of the ceramic surfaces with the asixymetric drop shape analysis contact diameter technique. Shear bond strength (SBS) was tested to a resin composite (Z100) with three different adhesive systems (Scotch bond Multipurpose Plus, Clearfil New Bond, ProBOND). Scanning electron microscopy (SEM) images were performed. Results: Nanoroughness values assessed in 50x50 ?m areas were higher for the HF group, these differences were not detected by profilometric analysis. HF treatment created the nano- roughest surfaces and the smallest CA (p<0.05), producing the highest SBS to the composite resin with all tested adhesive systems (p<0.05). No diffe- rences existed between the SBS produced by the adhesive systems evaluated with any of the surface treatments tested. Conclusions: Nano-roughness obtained in a 50x50 ?m scan size areas was the most reliable data to evaluate the topographical changes produced by the different acid treatments on ceramic surfaces

    Riemannian submersions from almost contact metric manifolds

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    In this paper we obtain the structure equation of a contact-complex Riemannian submersion and give some applications of this equation in the study of almost cosymplectic manifolds with Kaehler fibres.Comment: Abh. Math. Semin. Univ. Hamb., to appea

    Modelos de gestión en nutrición clínica. Puntos débiles y puntos fuertes

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    En el VIº Foro de Debate Abbott-SENPE se establece una discusión multidisciplinar y multiprofesional para buscar el o los modelos de gestión clínica que consideramos más adecuados para la Unidades de Nutrición Clínica y Dietética (UNCyD) en España. Se valoran los puntos débiles y fuertes así como las oportunidades de los actuales sistemas y se concluye en la observación de una cierta disparidad vinculada no solo a las comunidades autónomas sino también a los diferentes tipos de hospital. Se propone, desde SENPE, la creación de un grupo de trabajo que ayude a la normalización de los modelos y a potenciar la cultura del Cuadro de Mandos Integral y de Gestión del Cambio.At the 6th Abbott-SENPE Debate Forum a multidisciplinary and multiprofessional discussion was established in order to seek for the model or the models of clinical management most appropriate for Clinical Nutrition and Dietetics Units (CNAD) in Spain. The weaknesses and strengths as well as opportunities for the current systems were assessed concluding that a certain degree of disparity was observed not only due to regional differences but also to different hospital types. It was proposed, from SENPE, the creation of a working group helping to standardize the models and promote the culture of Integral Control and Change Management

    The photosensitizing activity of lumazine using 2'-deoxyguanosine 5'-monophosphate and HeLa cells as targets

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    Lumazines are an important family of heterocyclic compounds present in biological systems as biosynthetic precursors and/or products of metabolic degradation. Upon UV irradiation, the specific compound called lumazine (pteridine-2,4(1,3H)-dione) is able to generate singlet oxygen (1O2), which is one of the main chemical species responsible for photodynamic effects. To further assess the photosensitizing capability of lumazine (Lum) experiments were performed using the nucleotide 2′-deoxyguanosine 5′-monophosphate (dGMP) and, independently, cervical cancer cells (HeLa cell line) as targets. In the dGMP experiments, the data revealed that dGMP indeed undergoes oxidation/oxygenation photoinduced by Lum. Moreover, dGMP disappearance proceeds through two competing pathways: (1) electron transfer between dGMP and excited-state Lum (Type I process) and (2) reaction of dGMP with 1O2 produced by Lum (Type II process). The multistep processes involved are convoluted and susceptible to changes in experimental conditions. The independent studies with HeLa cells included fluorescence analysis of cell extracts and phototoxicity experiments performed at the single-cell level. Results showed that, upon Lum uptake and irradiation, photodynamic effects occur. In particular, the mitochondria and cell membrane were perturbed, both of which reflect key stages in cell death. The data reported herein illustrate how the irradiation of an endogenous biological compound can have various effects which, depending on the system, can be manifested in different ways.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

    Magnetic vortex filament flows

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    We exhibit a variational approach to study the magnetic flow associated with a Killing magnetic field in dimension 3. In this context, the solutions of the Lorentz force equation are viewed as Kirchhoff elastic rods and conversely. This provides an amazing connection between two apparently unrelated physical models and, in particular, it ties the classical elastic theory with the Hall effect. Then, these magnetic flows can be regarded as vortex filament flows within the localized induction approximation. The Hasimoto transformation can be used to see the magnetic trajectories as solutions of the cubic nonlinear Schrödinger equation showing the solitonic nature of those.Ministerio de Educación y CienciaFondo Europeo de Desarrollo RegionalJunta de Andalucí

    Importancia del agua en la hidratación de la población española: documento FESNAD 2010

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    For any healthy individual, thirst is an appropriate sign to drink water, except for babies, sportsmen, and most of ill and elderly people. In these instances, it is convenient to schedule appropriate times to drink water since great demands and the physiological mechanisms that determine thirst in these situations may condition water unbalances with important consequences for health and the physical and intellectual performance. The human body has a number of mechanisms that allow keeping constant the water content by adjusting intakes and wastes. Water balance is determined by intake (consumed water, beverages, and water contained in foods) and wastes (urine, stools, the skin, and expired air from the lungs). Failure of these mechanisms and subsequent impairments in water balance may produce severe disarrangements that may threaten somebody's life. In the present document, we analyze the evidences regarding the factors conditioning water needs in the different life stages and physiological situations, as well as the consequences of water unbalance under different situations. A proper hydration may be achieved by feeding and the use of water and other liquids. Although water is the beverage by excellence and represents the ideal way of restoring the losses and get hydrated, we should be aware that, from the very beginning, we have sought other liquid sources with hydration properties. In the last decades we have increased the consumption of different beverages, with a proliferation of sugar-containing beverages. Since excessive sugar consumption has been related to obesity and other chronic conditions, it is evident that the use of these caloric beverages should be rationalized, especially in children. In this document all the considerations regarding hydration are presented and different recommendations are expose

    Genomic and serologic characterization of enterovirus A71 brainstem encephalitis

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    OBJECTIVE: In 2016, Catalonia experienced a pediatric brainstem encephalitis outbreak caused by enterovirus A71 (EV-A71). Conventional testing identified EV in the periphery but rarely in CSF. Metagenomic next-generation sequencing (mNGS) and CSF pan-viral serology (VirScan) were deployed to enhance viral detection and characterization. METHODS: RNA was extracted from the CSF (n = 20), plasma (n = 9), stool (n = 15), and nasopharyngeal samples (n = 16) from 10 children with brainstem encephalitis and 10 children with meningitis or encephalitis. Pathogens were identified using mNGS. Available CSF from cases (n = 12) and pediatric other neurologic disease controls (n = 54) were analyzed with VirScan with a subset (n = 9 and n = 50) validated by ELISA. RESULTS: mNGS detected EV in all samples positive by quantitative reverse transcription polymerase chain reaction (qRT-PCR) (n = 25). In qRT-PCR-negative samples (n = 35), mNGS found virus in 23% (n = 8, 3 CSF samples). Overall, mNGS enhanced EV detection from 42% (25/60) to 57% (33/60) (p-value = 0.013). VirScan and ELISA increased detection to 92% (11/12) compared with 46% (4/12) for CSF mNGS and qRT-PCR (p-value = 0.023). Phylogenetic analysis confirmed the EV-A71 strain clustered with a neurovirulent German EV-A71. A single amino acid substitution (S241P) in the EVA71 VP1 protein was exclusive to the CNS in one subject. CONCLUSION: mNGS with VirScan significantly increased the CNS detection of EVs relative to qRT-PCR, and the latter generated an antigenic profile of the acute EV-A71 immune response. Genomic analysis confirmed the close relation of the outbreak EV-A71 and neuroinvasive German EV-A71. A S241P substitution in VP1 was found exclusively in the CSF.Grants supporting this project include the National Multiple Sclerosis Society and the American Academy of Neurology award FAN-1608-25607 (R.D.S.), Clinical Research Training Scholarship P0534134 (P.S.R.), Sandler and William K. Bowes Jr Foundations (M.R.W., J.L.D., L.M.K., H.A.S., K.C.Z.), Rachleff Family Foundation (M.R.W.), and NINDS of the NIH under award K08NS096117 (M.R.W.) and F31NS113432 (K.E.L.). This study was partially supported by a grant from the Spanish National Health Institute [grant number PI15CIII-00020] and the European Regional Development Fund (FEDER funds). UCSF Biomedical Sciences Program (I.A.H., K.E.L.), UCSF Medical Scientist Training Program (K.E.L.), and the Chan Zuckerberg Biohub (J.E.P., W.W., C.K.C., J.L.D., E.D.C.) also supported this project.S

    An outbreak of coxsackievirus A6 hand, foot, and mouth disease associated with onychomadesis in Taiwan, 2010

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    <p>Abstract</p> <p>Background</p> <p>In 2010, an outbreak of coxsackievirus A6 (CA6) hand, foot and mouth disease (HFMD) occurred in Taiwan and some patients presented with onychomadesis and desquamation following HFMD. Therefore, we performed an epidemiological and molecular investigation to elucidate the characteristics of this outbreak.</p> <p>Methods</p> <p>Patients who had HFMD with positive enterovirus isolation results were enrolled. We performed a telephone interview with enrolled patients or their caregivers to collect information concerning symptoms, treatments, the presence of desquamation, and the presence of nail abnormalities. The serotypes of the enterovirus isolates were determined using indirect immunofluorescence assays. The VP1 gene was sequenced and the phylogenetic tree for the current CA6 strains in 2010, 52 previous CA6 strains isolated in Taiwan from 1998 through 2009, along with 8 reference sequences from other countries was constructed using the neighbor-joining command in MEGA software.</p> <p>Results</p> <p>Of the 130 patients with laboratory-confirmed CA6 infection, some patients with CA6 infection also had eruptions around the perioral area (28, 22%), the trunk and/or the neck (39, 30%) and generalized skin eruptions (6, 5%) in addition to the typical presentation of skin eruptions on the hands, feet, and mouths. Sixty-six (51%) CA6 patients experienced desquamation of palms and soles after the infection episode and 48 (37%) CA6 patients developed onychomadesis, which only occurred in 7 (5%) of 145 cases with non-CA6 enterovirus infection (<it>p </it>< 0.001). The sequences of viral protein 1 of CA6 in 2010 differ from those found in Taiwan before 2010, but are similar to those found in patients in Finland in 2008.</p> <p>Conclusions</p> <p>HFMD patients with CA6 infection experienced symptoms targeting a broader spectrum of skin sites and more profound tissue destruction, i.e., desquamation and nail abnormalities.</p
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