Organic Aerosol source apportionment in London 2013 with ME-2:Exploring the solution space with annual and seasonal analysis

The multilinear engine (ME-2) factorization tool is being widely used following the recent development of the Source Finder (SoFi) interface at the Paul Scherrer Institute. However, the success of this tool, when using the <i>a</i> value approach, largely depends on the inputs (i.e. target profiles) applied as well as the experience of the user. A strategy to explore the solution space is proposed, in which the solution that best describes the organic aerosol (OA) sources is determined according to the systematic application of predefined statistical tests. This includes trilinear regression, which proves to be a useful tool for comparing different ME-2 solutions. Aerosol Chemical Speciation Monitor (ACSM) measurements were carried out at the urban background site of North Kensington, London from March to December 2013, where for the first time the behaviour of OA sources and their possible environmental implications were studied using an ACSM. Five OA sources were identified: biomass burning OA (BBOA), hydrocarbon-like OA (HOA), cooking OA (COA), semivolatile oxygenated OA (SVOOA) and low-volatility oxygenated OA (LVOOA). ME-2 analysis of the seasonal data sets (spring, summer and autumn) showed a higher variability in the OA sources that was not detected in the combined March–December data set; this variability was explored with the triangle plots <i>f</i>44 : <i>f</i>43 <i>f</i>44 : <i>f</i>60, in which a high variation of SVOOA relative to LVOOA was observed in the <i>f</i>44 : <i>f</i>43 analysis. Hence, it was possible to conclude that, when performing source apportionment to long-term measurements, important information may be lost and this analysis should be done to short periods of time, such as seasonally. Further analysis on the atmospheric implications of these OA sources was carried out, identifying evidence of the possible contribution of heavy-duty diesel vehicles to air pollution during weekdays compared to those fuelled by petrol

Seasonal abundance of Diaphorina citri (Hemiptera: Liviidae) in citrus groves in Cazones, Veracruz, México

Se evaluó la abundancia estacional del Psílido Asiático de los Cítricos Diaphorina citri Kuwayama, en plantaciones de cítricos en la región de Cazones, Veracruz, México. Durante el período de Febrero de 2010 a Febrero de 2012 se realizaron registros quincenales de adultos de D. citri en trampas amarillas, así como la presencia de huevos, ninfas, adultos y enemigos  naturales en los brotes. Las poblaciones del psílido se presentaron durante todo el periodo de estudio, detectando picos poblacionales en Febrero, Marzo, Abril y Julio en las plantaciones. Los incrementos en las infestaciones del psílido mostraron una relación positiva con respecto a la abundancia de brotes, y éstos a su vez, con latemperatura y precipitación. Durante el periodo de estudio, los enemigos naturales no fueron un factor determinante en la regulación de las poblaciones del psílido, mientras que la abundancia de brotes en los árboles de cítricos, representa un factor clave en el manejo integrado de esta plaga.Seasonal abundance of the Asian Citrus Psyllid, Diaphorina citri Kuwayama, wasevaluated on citrus groves in the region of Cazones, Veracruz, Mexico. For the period from February 2010 to February 2012, biweekly records for adult specimens were made using yellow sticky cardboard traps, as well as the presence of eggs, nymphs, adults, and natural enemies on the flush shoots were also registered. Psyllid populations occurred throughout the period of study, detecting population peaks on February, March, April and July in the citrus plantations. Increases of psyllid infestations were positively related to the abundance of new shoot flushes, and these in turn, were related to the temperature and rainfall. Natural enemies were not a decisive factor in regulating liviid populations, while the abundance of shoot flushes produced by citrus treescould play an important role in integrated psyllid management

Structure of the Collision Zone Between the Nazca Ridge and the Peruvian Convergent Margin: Geodynamic and Seismotectonic Implications

We study the structure and tectonics of the collision zone between the Nazca Ridge (NR) and the Peruvian margin constrained by seismic, gravimetric, bathymetric, and natural seismological data. The NR was formed in an on-ridge setting, and it is characterized by a smooth and broad shallow seafloor (swell) with an estimated buoyancy flux of ~7 Mg/s. The seismic results show that the NR hosts an oceanic lower crust 10–14 km thick with velocities of 7.2–7.5 km/s suggesting intrusion of magmatic material from the hot spot plume to the oceanic plate. Our results show evidence for subduction erosion in the frontal part of the margin likely enhanced by the collision of the NR. The ridge-trench collision zone correlates with the presence of a prominent normal scarp, a narrow continental slope, and (uplifted) shelf. In contrast, adjacent of the collision zone, the slope does not present a topographic scarp and the continental slope and shelf become wider and deeper. Geophysical and geodetic evidence indicate that the collision zone is characterized by low seismic coupling at the plate interface. This is consistent with vigorous subduction erosion enhanced by the subducting NR causing abrasion and increase of fluid pore pressure at the interplate contact. Furthermore, the NR has behaved as a barrier for rupture propagation of megathrust earthquakes (e.g., 1746 Mw 8.6 and 1942 Mw 8.1 events). In contrast, for moderate earthquakes (e.g., 1996 Mw 7.7 and 2011 Mw 6.9 events), the NR has behaved as a seismic asperity nucleating at depths >20 km

Sources of non-methane hydrocarbons in surface air in Delhi, India

Rapid economic growth and development have exacerbated air quality problems across India, driven by many poorly understood pollution sources and understanding their relative importance remains critical to characterising the key drivers of air pollution. A comprehensive suite of measurements of 90 non-methane hydrocarbons (NMHCs) (C2–C14), including 12 speciated monoterpenes and higher molecular weight monoaromatics, were made at an urban site in Old Delhi during the pre-monsoon (28-May to 05-Jun 2018) and post-monsoon (11 to 27-Oct 2018) seasons using dual-channel gas chromatography (DC-GC-FID) and two-dimensional gas chromatography (GC×GC-FID). Significantly higher mixing ratios of NMHCs were measured during the post-monsoon campaign, with a mean night-time enhancement of around 6. Like with NOx and CO, strong diurnal profiles were observed for all NMHCs, except isoprene, with very high NMHC mixing ratios between 35–1485 ppbv. The sum of mixing ratios of benzene, toluene, ethylbenzene and xylenes (BTEX) routinely exceeded 100 ppbv at night during the post-monsoon period, with a maximum measured mixing ratio of monoaromatic species of 370 ppbv. The mixing ratio of highly reactive monoterpenes peaked at around 6 ppbv in the post-monsoon campaign and correlated strongly with anthropogenic NMHCs, suggesting a strong non-biogenic source in Delhi. A detailed source apportionment study was conducted which included regression analysis to CO, acetylene and other NMHCs, hierarchical cluster analysis, EPA UNMIX 6.0, principal component analysis/absolute principal component scores (PCA/APCS) and comparison with NMHC ratios (benzene/toluene and i-/n-pentane) in ambient samples to liquid and solid fuels. These analyses suggested the primary source of anthropogenic NMHCs in Delhi was from traffic emissions (petrol and diesel), with average mixing ratio contributions from Unmix and PCA/APCS models of 38% from petrol, 14% from diesel and 32% from liquified petroleum gas (LPG) with a smaller contribution (16%) from solid fuel combustion. Detailed consideration of the underlying meteorology during the campaigns showed that the extreme night-time mixing ratios of NMHCs during the post-monsoon campaign were the result of emissions into a very shallow and stagnant boundary layer. The results of this study suggest that despite widespread open burning in India, traffic-related petrol and diesel emissions remain the key drivers of gas-phase urban air pollution in Delhi

Seasonal analysis of submicron aerosol in Old Delhi using high-resolution aerosol mass spectrometry: chemical characterisation, source apportionment and new marker identification

We present the first real-time composition of submicron particulate matter (PM1) in Old Delhi using high-resolution aerosol mass spectrometry (HR-AMS). Old Delhi is one of the most polluted locations in the world, and PM1 concentrations reached ∼ 750 µg m−3 during the most polluted period, the post-monsoon period, where PM1 increased by 188 % over the pre-monsoon period. Sulfate contributes the largest inorganic PM1 mass fraction during the pre-monsoon (24 %) and monsoon (24 %) periods, with nitrate contributing most during the post-monsoon period (8 %). The organics dominate the mass fraction (54 %–68 %) throughout the three periods, and, using positive matrix factorisation (PMF) to perform source apportionment analysis of organic mass, two burning-related factors were found to contribute the most (35 %) to the post-monsoon increase. The first PMF factor, semi-volatility biomass burning organic aerosol (SVBBOA), shows a high correlation with Earth observation fire counts in surrounding states, which links its origin to crop residue burning. The second is a solid fuel OA (SFOA) factor with links to local open burning due to its high composition of polyaromatic hydrocarbons (PAHs) and novel AMS-measured marker species for polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Two traffic factors were resolved: one hydrocarbon-like OA (HOA) factor and another nitrogen-rich HOA (NHOA) factor. The N compounds within NHOA were mainly nitrile species which have not previously been identified within AMS measurements. Their PAH composition suggests that NHOA is linked to diesel and HOA to compressed natural gas and petrol. These factors combined make the largest relative contribution to primary PM1 mass during the pre-monsoon and monsoon periods while contributing the second highest in the post-monsoon period. A cooking OA (COA) factor shows strong links to the secondary factor, semi-volatility oxygenated OA (SVOOA). Correlations with co-located volatile organic compound (VOC) measurements and AMS-measured organic nitrogen oxides (OrgNO) suggest SVOOA is formed from aged COA. It is also found that a significant increase in chloride concentrations (522 %) from pre-monsoon to post-monsoon correlates well with SVBBOA and SFOA, suggesting that crop residue burning and open waste burning are responsible. A reduction in traffic emissions would effectively reduce concentrations across most of the year. In order to reduce the post-monsoon peak, sources such as funeral pyres, solid waste burning and crop residue burning should be considered when developing new air quality policy

Deciphering CHFR role in pancreatic ductal adenocarcinoma

Checkpoint with forkhead-associated and ring finger domains (CHFR) has been proposed as a predictive and prognosis biomarker for different tumor types, but its role in pancreatic ductal adenocarcinoma (PDAC) remains unknown. The aim of this study was two-pronged: to review the role of CHFR in PDAC and evaluating CHFR as a potential predictive biomarker in this disease. For this purpose, we first explored the CHFR messenger (m)RNA expression and promoter methylation through the TCGA database. Secondly, the CHFR expression and promoter methylation were prospectively evaluated in a cohort of patients diagnosed with borderline (n = 19) or resectable (n = 16) PDAC by immunohistochemistry (IHC), methylation specific-PCR (MSP), and pyrosequencing. The results from the TCGA database showed significant differences in terms of progression-free survival (PFS) and overall survival (OS) based on the CHFR mRNA expression, which was likely independent from the promoter methylation. Importantly, our results showed that in primarily resected patients and also the entire cohort, a higher CHFR expression as indicated by the higher IHC staining intensity might identify patients with longer disease-free survival (DFS) and OS, respectively. Similarly, in the same cohorts, patients with lower methylation levels by pyrosequencing showed significantly longer OS than patients without this pattern. Both, the CHFR expression intensity and its promoter methylation were established as independent prognostic factors for PFS and OS in the entire cohort. In contrast, no significant differences were found between different methylation patterns for CHFR and the response to taxane-based neoadjuvant treatment. These results suggest the potential role of the higher expression of CHFR and the methylation pattern of its promoter as potential prognostic biomarkers in PDAC, thus warranting further comprehensive studies to extend and confirm our preliminary findings.This work was funded by grants from the Department of Health from the Government of Navarra (Ref. 008-2018), REFBIO II Pyrenees Biomedical Network from Programa INTERREG V-A España-Francia-Andorra (Ref. BMK_PANC) and Sociedad Española de Oncología Médica (SEOM) to AV. IG-B was supported by a predoctoral fellowship from the Department of Economic Development Government of Navarre Ayudas para la contratación de doctorandos y doctorandas por empresas y organismos de investigación y difusión de conocimientos: doctorados industriales 2018–2020. Intensification Programme Navarrabiomed 2017-2021 Obra Social La Caixa Fundación Caja Navarra. This work has also been supported by the Spanish Ministry of Economy [MINECO; BFU2016-80360-R (to JC)] and the Ministry of Science and Innovation [MICINN; PID2019-105201RB-I00 (to JC)]. Instituto de Salud Carlos III, co-funded by European Union (ERDF/ESF, Investing in your future) [Predoctoral contract FI17/00282 (to EA-P)]. Junta de Andalucía (BIO-0139); GETNE2016 and GETNE2019 Research grants (to JC); and CIBERobn

Simulating organic aerosol in Delhi with WRF-Chem using the volatility-basis-set approach: exploring model uncertainty with a Gaussian process emulator

The nature and origin of organic aerosol in the atmosphere remain unclear. The gas–particle partitioning of semi-volatile organic compounds (SVOCs) that constitute primary organic aerosols (POAs) and the multigenerational chemical aging of SVOCs are particularly poorly understood. The volatility basis set (VBS) approach, implemented in air quality models such as WRF-Chem (Weather Research and Forecasting model with Chemistry), can be a useful tool to describe emissions of POA and its chemical evolution. However, the evaluation of model uncertainty and the optimal model parameterization may be expensive to probe using only WRF-Chem simulations. Gaussian process emulators, trained on simulations from relatively few WRF-Chem simulations, are capable of reproducing model results and estimating the sources of model uncertainty within a defined range of model parameters. In this study, a WRF-Chem VBS parameterization is proposed; we then generate a perturbed parameter ensemble of 111 model runs, perturbing 10 parameters of the WRF-Chem model relating to organic aerosol emissions and the VBS oxidation reactions. This allowed us to cover the model's uncertainty space and to compare outputs from each run to aerosol mass spectrometer observations of organic aerosol concentrations and O:C ratios measured in New Delhi, India. The simulations spanned the organic aerosol concentrations measured with the aerosol mass spectrometer (AMS). However, they also highlighted potential structural errors in the model that may be related to unsuitable diurnal cycles in the emissions and/or failure to adequately represent the dynamics of the planetary boundary layer. While the structural errors prevented us from clearly identifying an optimized VBS approach in WRF-Chem, we were able to apply the emulator in the following two periods: the full period (1–29 May) and a subperiod period of 14:00–16:00 h LT (local time) on 1–29 May. The combination of emulator analysis and model evaluation metrics allowed us to identify plausible parameter combinations for the analyzed periods. We demonstrate that the methodology presented in this study can be used to determine the model uncertainty and to identify the appropriate parameter combination for the VBS approach and hence to provide valuable information to improve our understanding of OA production

VOLUMEN 24, NÚMERO 39 (2002)

ESTUDIO DEL PROCESO DE REHIDRATACIÓN DE LAS ROCAS METAMÓRFICAS DE LA FORMACIÓN SILGARÁ A PARTIR DEL ANÁLISIS COMPOSICIONAL DE LA CLORITA, REGIÓN SUROCCIDENTAL DEL MACIZO DE SANTANDER. Mantilla Figueroa, L. C.; Ríos Reyes, C. A.; Castellanos Alarcón, O. M.DETERMINACIÓN DE PALEOTEMPERATURAS EN LA CUENCA CRETÁCICA DE CAMEROS (LA RIOJA, ESPAÑA), A PARTIR DEL ESTUDIO DE CLORITAS. Mantilla Figueroa, L. C.FALLAS LONGITUDINALES Y TRANSVERSALES EN LA SABANA DE BOGOTÁ, COLOMBIA. Velandia Patiño, F. A.; De Bermoudes, O.ESTUDIO GEOQUÍMICO DE ELEMENTOS DE TIERRAS RARAS (REE) EN LAS FLUORITAS DE LAS MINAS PALESTINA (MUNICIPIO DE CEPITÁ) Y EL LLANITO (MUNICIPIO DE LOS SANTOS) EN EL DEPARTAMENTO DE SANTANDER: APORTE AL CONOCIMIENTODEL MODELO GENÉTICO. Mantilla Figueroa, L. C.; Mesa, A.CONDICIONES GEOLÓGICAS FAVORABLES DE LAS SEDIMENTITAS CRETÁCICAS DE LA CORDILLERA ORIENTAL DE COLOMBIA PARA LA EXISTENCIA DE DEPÓSITOS EXHALATIVOS SUBMARINOS DE PLOMO Y ZINC. Sarmiento Rojas, L. F.VISUALIZACIÓN EN TRES DIMENSIONES, LOS MAPAS DE AMENAZA VOLCÁNICA EDUCAN AL CIUDADANO COMÚN. Villegas, H.CÁLCULO DE LA PROBABILIDAD ABSOLUTA DE UNA NUEVA ERUPCIÓN EN LA ISLA DE ISCHIA (ITALIA). Mattera, M.EVALUACIÓN DEL RIESGO VOLCÁNICO EN LA ISLA DE ISCHIA (ITALIA). Mattera, M.METODOLOGÍA PARA LA DEFINICIÓN, EVALUACIÓN Y VALORACIÓN DEL PATRIMONIO GEOLOGICO Y SU APLICACIÓN EN LA GEOMORFOLOGÍA GLACIAR DE SANTANDER (MUNICIPIO DE VETAS). Colegial, J. D.; Pisciotti, G.; Uribe, E

VOLUMEN 24, NÚMERO 39 (2002)

ESTUDIO DEL PROCESO DE REHIDRATACIÓN DE LAS ROCAS METAMÓRFICAS DE LA FORMACIÓN SILGARÁ A PARTIR DEL ANÁLISIS COMPOSICIONAL DE LA CLORITA, REGIÓN SUROCCIDENTAL DEL MACIZO DE SANTANDER. Mantilla Figueroa, L. C.; Ríos Reyes, C. A.; Castellanos Alarcón, O. M.DETERMINACIÓN DE PALEOTEMPERATURAS EN LA CUENCA CRETÁCICA DE CAMEROS (LA RIOJA, ESPAÑA), A PARTIR DEL ESTUDIO DE CLORITAS. Mantilla Figueroa, L. C.FALLAS LONGITUDINALES Y TRANSVERSALES EN LA SABANA DE BOGOTÁ, COLOMBIA. Velandia Patiño, F. A.; De Bermoudes, O.ESTUDIO GEOQUÍMICO DE ELEMENTOS DE TIERRAS RARAS (REE) EN LAS FLUORITAS DE LAS MINAS PALESTINA (MUNICIPIO DE CEPITÁ) Y EL LLANITO (MUNICIPIO DE LOS SANTOS) EN EL DEPARTAMENTO DE SANTANDER: APORTE AL CONOCIMIENTODEL MODELO GENÉTICO. Mantilla Figueroa, L. C.; Mesa, A.CONDICIONES GEOLÓGICAS FAVORABLES DE LAS SEDIMENTITAS CRETÁCICAS DE LA CORDILLERA ORIENTAL DE COLOMBIA PARA LA EXISTENCIA DE DEPÓSITOS EXHALATIVOS SUBMARINOS DE PLOMO Y ZINC. Sarmiento Rojas, L. F.VISUALIZACIÓN EN TRES DIMENSIONES, LOS MAPAS DE AMENAZA VOLCÁNICA EDUCAN AL CIUDADANO COMÚN. Villegas, H.CÁLCULO DE LA PROBABILIDAD ABSOLUTA DE UNA NUEVA ERUPCIÓN EN LA ISLA DE ISCHIA (ITALIA). Mattera, M.EVALUACIÓN DEL RIESGO VOLCÁNICO EN LA ISLA DE ISCHIA (ITALIA). Mattera, M.METODOLOGÍA PARA LA DEFINICIÓN, EVALUACIÓN Y VALORACIÓN DEL PATRIMONIO GEOLOGICO Y SU APLICACIÓN EN LA GEOMORFOLOGÍA GLACIAR DE SANTANDER (MUNICIPIO DE VETAS). Colegial, J. D.; Pisciotti, G.; Uribe, E