1,025 research outputs found
Transport of desert dust mixed with North African industrial pollutants in the subtropical Saharan Air Layer
An analysis of chemical composition data of particulate matter samples (TSP, PM<sub>10</sub> and PM<sub>2.5</sub>) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izaña Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the dust and particulate pollutants. Areas located at the south of the southern slope of the Atlas mountains emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring in Northern Algeria, Eastern Algeria, Tunisia and the Atlantic coast of Morocco appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least 60 % of the sulphate <10 μm transported from some regions) observed in the SAL. These emissions are mostly linked to crude oil refineries, phosphate-based fertilizer industry and power plants. Although desert dust emissions appear as the most frequent source of the phosphorous observed in the SAL, high P concentrations are observed when the SAL is affected by emissions from open mines of phosphate and phosphate based fertilizer industry. The results also show that a significant fraction of the sulphate (up to 90 % of sulphate <10 μm transported from some regions) observed in the SAL may be influenced by soil emissions of evaporite minerals in well defined regions where dry saline lakes (chotts) are present. These interpretations of the MCAR plots are consistent with the results obtained with the Positive Matrix Factorization (PMF2) receptor modelling. The results of this study show that North African industrial pollutants may be mixed with desert dust and exported to the North Atlantic in the Saharan Air Layer
Oxidative stress is tightly regulated by cytochrome c phosphorylation and respirasome factors in mitochondria
Respiratory cytochrome c has been found to be phosphorylated at tyrosine 97 in the postischemic brain upon neuroprotective insulin treatment, but how such posttranslational modification affects mitochondrial metabolism is unclear. Here, we report the structural features and functional behavior of a phosphomimetic cytochrome c mutant, which was generated by site-specific incorporation at position 97 of p-carboxymethyl-l-phenylalanine using the evolved tRNA synthetase method. We found that the point mutation does not alter the overall folding and heme environment of cytochrome c, but significantly affects the entire oxidative phosphorylation process. In fact, the electron donation rate of the mutant heme protein to cytochrome c oxidase, or complex IV, within respiratory supercomplexes was higher than that of the wild-type species, in agreement with the observed decrease in reactive oxygen species production. Direct contact of cytochrome c with the respiratory supercomplex factor HIGD1A (hypoxia-inducible domain family member 1A) is reported here, with the mutant heme protein exhibiting a lower affinity than the wild-type species. Interestingly, phosphomimetic cytochrome c also exhibited a lower caspase-3 activation activity. Altogether, these findings yield a better understanding of the molecular basis for mitochondrial metabolism in acute diseases, such as brain ischemia, and thus could allow the use of phosphomimetic cytochrome c as a neuroprotector with therapeutic applications.España, Junta de Andalucía BIO-198España MINECO BFU2015-71017/BM
Nonpuerperal Breast Infection
Objective: We undertook a microbiological study of purulent specimens from women with symptomatic breast abscesses
Direct specific isotopic analysis of compounds released by pyrolysis (Py-CSIA): Novel applications in paleoenvironmental studies
Poster J.03 presentado en el The 40th International Symposium on Capillary Chromatography and 13th GCxGC Symposium May 29-June 03, (2016) Riva del Garda Fierecongressi, Riva del Garda, Italyisotopic analysis (Py-CSIA) and analytical pyrolysis (Py-GC/MS) opens new windows of information and is particularly useful to study solid materials that are not soluble and therefore not amenable by conventional GC/MS techniques. Py-CSIA is a rather novel hyphenated technique that combines the chromatographic separation of compounds released by pyrolysis (Py-GC) with an isotope ratio mass spectrometer (IRMS). The technique allows the measurement of stable isotope proportions i.e., δ13C, δ15N and δ2H, δ18O in specific compounds released by pyrolysis. The sample preparation is minimized and a molecular fingerprinting of the material is achieved.N
Comparative assessment of satellite- and drone-based vegetation indices to predict arthropod biomass in shrub-steppes
Arthropod biomass is a key element in ecosystem functionality and a basic
food item for many species. It must be estimated through traditional costly
field sampling, normally at just a few sampling points. Arthropod biomass and
plant productivity should be narrowly related because a large majority of
arthropods are herbivorous, and others depend on these. Quantifying plant
productivity with satellite or aerial vehicle imagery is an easy and fast procedure already tested and implemented in agriculture and field ecology.
However, the capability of satellite or aerial vehicle imagery for quantifying
arthropod biomass and its relationship with plant productivity has been
scarcely addressed. Here, we used unmanned aerial vehicle (UAV) and satellite Sentinel-2 (S2) imagery to establish a relationship between plant productivity and arthropod biomass estimated through ground-truth field sampling in
shrub steppes. We UAV-sampled seven plots of 47.6–72.3 ha at a 4-cm pixel
resolution, subsequently downscaling spatial resolution to 50 cm resolution.
In parallel, we used S2 imagery from the same and other dates and locations at
10-m spatial resolution. We related several vegetation indices (VIs) with
arthropod biomass (epigeous, coprophagous, and four functional consumer
groups: predatory, detritivore, phytophagous, and diverse) estimated at 41–48
sampling stations for UAV flying plots and in 67–79 sampling stations for S2.
VIs derived from UAV were consistently and positively related to all arthropod
biomass groups. Three out of seven and six out of seven S2-derived VIs were
positively related to epigeous and coprophagous arthropod biomass, respectively. The blue normalized difference VI (BNDVI) and enhanced normalized
difference VI (ENDVI) showed consistent and positive relationships with
arthropod biomass, regardless of the arthropod group or spatial resolution. Our results showed that UAV and S2-VI imagery data may be viable and
cost-efficient alternatives for quantifying arthropod biomass at large scales
in shrub steppes. The relationship between VI and arthropod biomass is
probably habitat-dependent, so future research should address this relationship and include several habitats to validate VIs as proxies of arthropod
biomassBBVA Foundation, BBVA Dron Ricoti
project; European Commission, Grant/
Award Number: LIFE15-NAT-ES-000802;
REMEDINAL-3 from CAM; European
Comission, Grant/Award Number:
LIFE20-NAT-ES-00013
Effect of a wildfire and of post-fire restoration actions in the organic matter structure in soil fractions
The impact of wildfires and of restoration actions on soil organic matter (SOM) content and structure was studied in a soil under pine (Pinus pinea) from Doñana National Park (SW Spain). Samples were collected from burnt areas before (B) and after post-fire restoration (BR) and compared with an unburnt (UB) site. Analytical pyrolysis (Py-GC/MS) was used to investigate SOM molecular composition in whole soil samples and in coarse (CF) and fine (FF) fractions. The results were interpreted using a van Krevelen graphical-statistical method. Highest total organic carbon (TOC) was found in UB soil and no differences were found between B and BR soils. The CF had the highest TOC values and FF presented differences among the three scenarios. Respect to SOM structure, the B soil was depleted in lignin and enriched in unspecific aromatics and polycyclic aromatic hydrocarbons, and in all scenarios, CF SOM consisted mainly of lignocellulose derived compounds and fatty acids. In general, FF SOM was found more altered than CF. High contribution of unspecific aromatic compounds and polycyclic aromatic hydrocarbons was observed in B-FF whereas BR-FF samples comprised considerable proportions of compounds from labile biomass, possibly due to soil mixing during rehabilitation actions. The fire caused a defunctionalisation of lignin-derived phenolics and the formation of pyrogenic compounds. The van Krevelen diagram was found useful to—at first sight—differentiate between chemical processes caused by fire and of the rehabilitation actions. Fire exerted SOM demethoxylation, dealkylation and dehydration. Our results indicate that soil management actions after the fire lead to an increase in aromaticity corresponding to the accumulation of lignin and polycyclic aromatic compounds. This suggests additional inputs from charred lignocellulosic biomass, including black carbon, that was incorporated into the soil during rehabilitation practices
Fire mediated geochemical alterations in Andosol’s SOM under Canarian Pine (Pinus canariensis) forest
4 páginas, 1 figura, 2 tablas, 26 referencias.-- FUEGORED 2010.-- Jornadas Internacionales celebradas del 6-10 de octubre 2010, en Santiago de Compostela, España.Peer reviewe
ACLIMATACIÓN AL ESTRÉS HÍDRICO DE PLANTAS DE UVA DE MESA cv. CRIMSON SEEDLESS CULTIVADAS EN MACETA
[ES] El objetivo de este estudio fue evaluar la capacidad de adaptación al estrés hídrico
de uva de mesa cv. Crimson Seedless x Paulsen 1103 cultivadas en maceta bajo
invernadero. Se aplicaron 5 tratamientos de riego: (i) CTL-1 y CTL-2; regados diariamente a
capacidad de campo; (ii) RD, regado al 50% del CTL-1; (iii) PRDFIX, regado al 50% del CTL-
1 en una maceta de forma fija, y (iv) PRDALT regado al 50% del CTL-1, en una maceta de
forma alterna. Transcurridos 30 días desde su aplicación, se suprimió el riego durante 7 días
a excepción de CTL-1. Posteriormente se reanudo el riego, y todas las plantas fueron
tratadas como CTL-1 durante 7 días. El comportamiento estomático de Crimson se
caracterizó como isohídrico, dado que reducciones de gs por debajo de 40 mmol m-2 s
-1
,
mantuvieron valores de Ψt,md dentro de un rango constante. Las condiciones de déficit
hídrico afectaron severamente a las plantas de los tratamientos PRDFIX y CTL-2, dado que,
independientemente de la recuperación observada en los valores de gs y ACO2, los daños
generados sobre su crecimiento vegetativo resultaron ser irreversibles. PRDALT y RD pueden
ser utilizados con fines de programación de riegos.Conesa, M.; De La Rosa, J.; Montemurro, L.; García, M.; Domingo, R.; Pérez-Pastor, A. (2015). ACLIMATACIÓN AL ESTRÉS HÍDRICO DE PLANTAS DE UVA DE MESA cv. CRIMSON SEEDLESS CULTIVADAS EN MACETA. En XXXIII CONGRESO NACIONAL DE RIEGOS. Valencia 16-18 junio de 2015. Editorial Universitat Politècnica de València. https://doi.org/10.4995/CNRiegos.2015.1435OC
Detection of cylindrospermopsin and its decomposition products in raw and cooked fish (Oreochromis niloticus) by analytical pyrolysis (Py-GC/MS)
The presence of the toxin cylindrospermopsin is increasingly frequent in samples from different ecosystems and it is a serious problem both at environmental level and for animal and human health. To be able to prevent CYN exposure risk, it is important to have suitable analytical methods, but also quick and economical ones. Analytical pyrolysis coupled to GC/MS (Py-GC/MS) represents an important alternative for the rapid detection, characterization or “fingerprinting” of different materials. However, it has been less studied with cyanotoxins up to date. The present work aims to investigate: 1) the suitability of Py-GC/MS for detection of CYN and its decomposition products in raw and cooked fish samples before consumption and 2) the influence of the different cooking methods on the presence of different CYN degradation products detected by Py-GC/MS. For first time, these results present that Py-GC/MS could be a rapid and economical alternative for the detection and monitoring of CYN and its degradation products (DP. m/z 290.1, 169.1 and 336.2) in raw or cooked fish. Moreover, the changes induced in CYN and DP by cooking could be amenable and detected by Py-GC/MS.Ministerio de Economía y Competitividad AGL2015-64558-R, CGL2016-78937-
Understanding the local and remote source contributions to ambient O3 during a pollution episode using a combination of experimental approaches in the Guadalquivir valley, southern Spain
The Guadalquivir Valley is one of three major O3 hotspots in Spain. An airborne and surface measurement campaign was carried out from July 9th to 11th, 2019 to quantify the local/regional O3 contributions using experimental approaches. Air quality and meteorology data from surface measurements, a microlight aircraft, a helium balloon, and remote sensing data (TROPOMI-NO2-ESA) were used to obtain the 3D distribution of O3 and various tracer pollutants.
O3 accumulation over 2.5 days started with inputs from oceanic air masses transported inland by sea breezes, which drew O3 and its precursors from a local/regional origin to the northeastern end of the basin. The orographic–meteorological setting of the valley caused vertical recirculation of the air masses inside the valley that caused the accumulation by increasing regional background O3 concentration by 25–30 ppb. Furthermore, possible Mediterranean O3 contributions and additional vertical recirculation through the entrainment zone of the convective boundary layer also contributed. Using particulate matter finer than 2.5 μm (PM2.5), ultrafine particles (UFP), and black carbon (BC) as tracers of local sources, we calculated that local contributions increased regional O3 levels by 20 ppb inside specific pollution plumes transported by the breeze into the valley, and by 10 ppb during midday when flying over an area with abundant agricultural burning during the morning. Air masses that crossed the southern boundaries of the Betic system at mid-altitude (400–1850 m a.s.l.) on July 10th and 11th may have provided additional O3. Meanwhile, a decreasing trend at high altitudes (3000–5000 m a.s.l.) was observed, signifying that the impact of stratospheric O3 intrusion decreased during the campaign
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