719 research outputs found

    A new algorithm for brown and black carbon identification and organic carbon detection in fine atmospheric aerosols by a multi-wavelength Aethalometer

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    A novel approach for the analysis of aerosol absorption coefficient measurements is presented. A 7-wavelenghts aethalometer has been employed to identify brown carbon (BrC) and black carbon (BC) and to detect organic carbon (OC) in fine atmospheric aerosols (PM2.5). The Magee Aethalometer estimates the BC content in atmospheric particulate by measuring the light attenuation in the aerosols accumulated on a quartz filter, at the standard wavelength λ = 0.88 μm. The known Magee algorithm is based on the hypothesis of a mass absorption coefficient inversely proportional to the wavelength. The new algorithm has been developed and applied to the whole spectral range; it verifies the spectral absorption behavior and, thus, it distinguishes between black and brown carbon. Moreover, it allows also to correct the absorption estimation at the UV wavelength commonly used to qualitatively detect the presence of mixed hydrocarbons. The algorithm has been applied to data collected in Agri Valley, located in Southern Italy, where torched crude oil undergoes a pre-treatment process. The Magee Aethalometer has been set to measure Aerosol absorption coefficients τaer (λ, t) every 5 min. Wavelength dependence of τaer (λ, t) has been analyzed by a best-fit technique and, excluding UV-wavelengths, both the absorption Angstrom coefficient α and the BC (or BrC) concentration have been determined. Finally, daily histograms of α provide information on optical properties of carbonaceous aerosol, while the extrapolation at UV-wavelengths gives information on the presence of semivolatile organic carbon (OC) particles

    Geological and geophysical characterization of the southeastern side of the High Agri Valley (southern Apennines, Italy)

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    Abstract. In the frame of a national project funded by Eni S.p.A. and developed by three institutes of the National Research Council (the Institute of Methodologies for Environmental Analysis, the Institute of Research for Hydrogeological Protection and the Institute for Electromagnetic Sensing of the Environment), a multidisciplinary approach based on the integration of satellite, aero-photogrammetric and in situ geophysical techniques was applied to investigate an area located in the Montemurro territory in the southeastern sector of the High Agri Valley (Basilicata Region, southern Italy). This paper reports the results obtained by the joint analysis of in situ geophysical surveys, aerial photos interpretation, morphotectonic investigation, geological field survey and borehole data. The joint analysis of different data allowed us (1) to show the shallow geological and structural setting, (2) to detect the geometry of the different lithological units and their mechanical and dynamical properties, (3) to image a previously unmapped fault beneath suspected scarps/warps and (4) to characterize the geometry of an active landslide affecting the study area

    Brief Communication: Rapid mapping of landslide events: the 3 December 2013 Montescaglioso landslide, Italy

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    We present an approach to measure 3-D surface deformations caused by large, rapid-moving landslides using the amplitude information of high-resolution, X-band synthetic aperture radar (SAR) images. We exploit SAR data captured by the COSMO-SkyMed satellites to measure the deformation produced by the 3 December 2013 Montescaglioso landslide, southern Italy. The deformation produced by the deep-seated landslide exceeded 10 m and caused the disruption of a main road, a few homes and commercial buildings. The results open up the possibility of obtaining 3-D surface deformation maps shortly after the occurrence of large, rapid-moving landslides using high-resolution SAR data

    Impact of Diabetes on Work Cessation: Data from the GAZEL cohort study

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    International audienceOBJECTIVE: To measure the impact of diabetes on work cessation, i.e., on the risks of work disability, early retirement, and death while in the labor force. RESEARCH DESIGN AND METHODS: We used data from the GAZEL prospective cohort of 20,625 employees of the French national gas and electricity company "EDF-GDF." We identified 506 employees with diabetes and randomly selected 2,530 nondiabetic employed control subjects matched for major sociodemographic and occupational characteristics. Using a multistate Cox model, we estimated hazard ratios (HRs) comparing the risks of transition from employment to disability, retirement, and death over time between participants with versus without diabetes. RESULTS: Employment rate decreased more rapidly in participants with diabetes (51.9 and 10.1% at 55 and 60 years, respectively) compared with nondiabetic participants (66.5 and 13.4%, respectively). Participants with diabetes had significantly increased risks of transition from employment to disability (HR 1.7 [95% CI 1.0-2.9]), retirement (HR 1.6 [1.5-1.8]), and death (HR 7.3 [3.6-14.6]) compared with participants without diabetes. Between 35 and 60 years, each participant with diabetes lost an estimated mean time of 1.1 year in the workforce (95% CI 0.99-1.14) compared with a nondiabetic participant. CONCLUSIONS: Our results provide evidence for a profound negative impact of diabetes on workforce participation in France. Social and economic consequences are major for patients, employers, and society-a burden that is likely to increase as diabetes becomes more and more common in the working-aged population

    Knockout studies reveal an important role of <i>plasmodium</i> lipoic acid protein ligase a1 for asexual blood stage parasite survival

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    Lipoic acid (LA) is a dithiol-containing cofactor that is essential for the function of a-keto acid dehydrogenase complexes. LA acts as a reversible acyl group acceptor and 'swinging arm' during acyl-coenzyme A formation. The cofactor is post-translationally attached to the acyl-transferase subunits of the multienzyme complexes through the action of octanoyl (lipoyl): &lt;i&gt;N&lt;/i&gt;-octanoyl (lipoyl) transferase (LipB) or lipoic acid protein ligases (LplA). Remarkably, apicomplexan parasites possess LA biosynthesis as well as scavenging pathways and the two pathways are distributed between mitochondrion and a vestigial organelle, the apicoplast. The apicoplast-specific LipB is dispensable for parasite growth due to functional redundancy of the parasite's lipoic acid/octanoic acid ligases/transferases. In this study, we show that &lt;i&gt;LplA1&lt;/i&gt; plays a pivotal role during the development of the erythrocytic stages of the malaria parasite. Gene disruptions in the human malaria parasite &lt;i&gt;P.falciparum&lt;/i&gt; consistently were unsuccessful while in the rodent malaria model parasite &lt;i&gt;P. berghei&lt;/i&gt; the &lt;i&gt;LplA1&lt;/i&gt; gene locus was targeted by knock-in and knockout constructs. However, the &lt;i&gt;LplA1&lt;/i&gt; &lt;sup&gt;(-)&lt;/sup&gt; mutant could not be cloned suggesting a critical role of LplA1 for asexual parasite growth &lt;i&gt;in vitro&lt;/i&gt; and &lt;i&gt;in vivo&lt;/i&gt;. These experimental genetics data suggest that lipoylation during expansion in red blood cells largely occurs through salvage from the host erythrocytes and subsequent ligation of LA to the target proteins of the malaria parasite
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