Characteristics And Temporal Variations Of Organic And Elemental Carbon Aerosols In A High–Altitude, Tropical Latin American Megacity

Bogota is a Latin American megacity located at an average altitude of 2600 m in the tropical Andes. It registers frequent episodes of poor air quality due to high PM10 concentrations. The carbonaceous fraction is the main PM10 component (>50%), but there is a lack of specific studies analyzing the characteristics and temporal variability of organic carbon (OC) and elemental carbon (EC) aerosols. In this study, daily samples (24±1h) were collected from June 2015 to May 2016 (a total of 308 samples) at an urban background site during an El Niño year, and the quartz filters were analyzed using a thermal-optical method. Results showed that EC and organic matter accounted for ~60% of the PM10 mass. The OC and EC averages were 8.92 ± 4.52 μg/m3 and 3.25 ± 1.59 μg/m3, respectively. The months with the highest average OC values were January to March, while EC concentrations were relatively constant throughout the year. Regarding daily values, the highest mean concentrations of OC (10.2 ± 5.13 μg/m3) and EC (3.73 ± 1.74 μg/m3) were obtained on Thursdays, and the lowest on Sundays (OC = 6.67 ± 3.04 μg/m3 and EC = 2.46 ± 0.94 μg/m3). The OC/EC ratio ranged from 1.66 (June) to 4.88 (March), with an annual average of 3.16 ± 2.01. The secondary organic carbon (SOC) contributions, measured using the EC-tracer method, accounted for 45% of the total OC. The effective carbon ratio, which indicates an association between carbonaceous particles and climate change, ranged from 0.12 (July) to 0.74 (May). The study of air-mass origins revealed that days with air mass from E + NE registered the highest OC concentrations. This research provides new data on the variability of carbonaceous aerosols over the course of a year. It also highlights forest fires as a significant source of OC and EC, and indicates the high impact of SOC on OC concentration at the sampling site

Power Quality Monitoring Integration into Distribution Automation through the Use of AMR

Power-quality events are of increasing concern for the economy because today’s equipment, particularly computers and automated manufacturing devices, is highly sensitive to such imperfections. With volatile energy rates and a need to control costs, regional agencies and utilities are interested in technologies to meter distribution use and manage utility information. Metering technologies and communications systems have advanced to enable the development of Automated Meter Reading (AMR) Systems. Power Quality is one area where the AMR system can be very valuable. This paper investigates the challenges in the development of distributed power-quality monitoring system. The approach of this paper is divided into metering, data collection, archiving, analysis, and presentation. It also discusses system architecture, implementation, and provides general guidelines in the tailoring of PQ indexes. This paper describes the challenges and lessons learned from this work.

Thiol precursors in Catarratto Bianco Comune and Grillo grapes and effect of clarification conditions on the release of varietal thiols in wine

Background and aims: Varietal thiols characterize the typical aroma of several white wines, as Sauvignon blanc. Their presence was suggested in two Sicilian grape cultivars, Catarratto Bianco Comune (CBC) and Grillo, thought it was not analytically proved to date. Methods and Results: Varietal thiol precursors and free varietal thiols were assessed in CBC and Grillo grapes, musts and wines by UPLC/high resolution mass spectrometry (HRMS). The isobaric compounds S-3-(hexanal)-glutathione (GSH-3MHAl) and S-3-(4-mercapto-4-methylpentan-2-one)-glutathione (GSH-4MMP) were discriminated by comparing their accurate masses and HR-MS/MS spectra with those of their synthetic standards. GSH-3MHAl, S-3-(hexan-1-ol)-glutathione (GSH-3MH) and S-3-(hexan-1-ol)-cysteine occurred in grape, must and wine, while GSH-4MMP and its hydrolysed forms did not. Their amounts decreased during the industrial winemaking processes, mostly following the grape pressing. We compared clarification conditions exposing must to either air or CO2 in terms of thiol precursors\u2019 and free thiols\u2019 content in wine. However, negligible differences were observed. Concentrations of free thiols in the range 400\u20131100 ng/L were found in the wines and they were not affected to the two clarification conditions adopted. Conclusion: The isobaric GSH-3MHAl and GSH-4MMP were clearly distinguished for the first time by UPLC-HRMS through their retention times and MS spectra. The varietal thiols were firstly revealed CBC and Grillo wines. The air-free and air- exposed clarification poorly affected the levels of varietal thiols. Significance of the study: This research highlights the major impact of the varietal thiols (mainly 3\u2013mercapto-hexan-1-ol and its acetate form) on the sensory properties of CBC and Grillo wines

Nanocarriers for topical delivery of resveratrol.

Purpose: The aim of the present work was to develop a nanocarrier-based formulation for topical delivery of resveratrol. Methods: Trans-resveratrol (t-res) was encapsulated in liposomes, ethosomes or transferosomes, by a modified hand-shaking method followed by extrusion. All the formulations were characterised in terms of mean diameter, size distribution (I.P.), t-res loading, t-res stability upon encapsulation during storage. The nanocarriers containing t-res were then introduced in cellulose-based gel to allow their final administration on the skin and the viscoelastic properties of the resulting formulation were investigated. Finally, we studied the inhibition of reactive oxygen species (ROS) in human keratinocyte (HaCaT) cell line stimulated with H2O2 for 24 h and then incubated with the t-res containing nanocarriers. Results: All the t-res containing carriers were characterised by a very high (close to 100%) encapsulation efficiency, a negligible t-res release at 4°C and stability of resveratrol in its trans form. The carriers only slightly influenced the viscoelastic characteristics of cellulose-based gels. Nanocarriers encapsulating t-res reduced, in a concentration-dependent manner, ROS production induced by H2O2 and this effect was higher when using t-res-encapsulating nanocarrier, with the higher effect observed in the case of ethosomes. Conclusions: In this work nanocarriers with high encapsulation efficiency, high physical stability and negligible t-res release during storage at 4°C were prepared. To allow their final administration on the skin, the nanocarrier can be easilisy loaded in cellulose-based gels without altering its rheological properties. Moreover, the use of t-res-encapsulating ethosomes led to an efficient antioxidant activity. Further ex vivo and in vivo studies will clarify the role of the different carrier when administered on the skin

Cross-reaction of naturally-produced β-lactamases from Citrobacter farmeri and Citrobacter amalonaticus with immunological detection of CTX-M enzymes.

The NG-Test CTX-M MULTI immunochromatographic assay has been developed to identify CTX-M-type β-lactamases in Enterobacterales, being the most widespread extended-spectrum β-lactamases. We showed here that the chromosomally-encoded ß-lactamases from Citrobacter farmeri and Citrobacter amalonaticus generated false-positive NG-Test CTX-M MULTI results, compromising the specificity of the test

Physicochemical Characterization And Sources Of The Thoracic Fraction Of Road Dust In A Latin American Megacity

Road dust has been identified as one of the main sources of outdoor PM10 in Bogota (a Latin American megacity), but there are no studies that have analyzed the physicochemical characteristics and origins of its respirable fraction. A characterization of inorganic compounds (water soluble ions, major and trace elements, organic and elemental carbon) and an analysis of source contributions to the PM10 fraction of road dust were carried out in this study. A total of twenty road dust samples, selected from representative industrial, residential and commercial areas, were swept and resuspended to obtain the thoracic fraction. Size distribution by laser diffraction and individual particle morphology by Scanning Electron Microscopy were also evaluated. The data obtained revealed that the volume (%) of thoracic particles was higher in samples from industrial zones where heavy vehicular traffic, industrial emissions and deteriorated pavements predominated. Crustal elements were the most abundant species, accounting for 49–62% of the thoracic mass, followed by OC (13–29%), water-soluble ions (1.4–3.8%), EC (0.8–1.9%) and trace elements (0.2–0.5%). The Coefficient of Divergence was obtained to identify the spatial variability of the samples. A source apportionment analysis was carried out considering the variability of chemical profiles, enrichment factors and ratios of Fe/Al, K/Al, Ca/Al, Ti/Al, Cu/Sb, Zn/Sb, OC/TC and OC/EC. By means of a PCA analysis, five components were identified, including local soils and pavement erosion (63%), construction and demolition activities (13%), industrial emissions (6%), brake wear (5%) and tailpipe emissions (4%). These components accounted for 91% of the total variance. The results provide data to understand better one of the main sources of PM10 emissions in Bogota, such as road dust. These data will be useful to optimize environmental policies, and they may be used in future studies of human health and air quality modeling

Bronchoscopic balloon dilatation in the management of bronchial stenosis following lung transplantation

SummaryBackgroundBronchial stenosis (BS) is currently found in 7–15% of lung transplantation (LT) recipients. Current treatment strategies have included Nd:Yag laser, cryotherapy, bougie dilatation and stent placement. Bronchoscopic balloon dilatation has been used as alternative treatment in a few cases with controversial results. This is a study to prospectively assess the efficacy of bronchoscopic balloon dilatation as a first step in the management of post-LT BS.MethodsFrom January 1995 to December 2002, bronchoscopic balloon dilatation was evaluated as first therapeutic option in all consecutive LT patients with BS. Symptoms, pulmonary function tests, airway diameter and use of other therapeutic techniques were evaluated.ResultsA total of 10 out of 284 anastomed airways (3.5%) in 9 out of 152 LT patients were included in the study and follow-up lasted from 6 to 81 months. Dilatation of all but one BS met with initial success: increase of both luminal dimensions and forced vital capacity (P=0.01), and relief of symptoms. Bronchoscopic balloon dilatation long-term follow-up showed effective results in 5 out of 10 (50%) bronchial stenoses, after an average of 4 bronchoscopic balloon dilatation procedures (range 1–8). No severe complications were observed. Stent placement was required in the other 5 bronchial stenoses.ConclusionsBronchoscopic balloon dilatation is a safe method that should be considered as first therapeutic treatment of post-LT BS. Its use avoids the need for stent placement in up to 50% of cases

Total organic carbon, total nitrogen and chemical characteristics of an haplic cambisol after biochar incorporation

Biochar has been used as a soil conditioner to increase the soil organic carbon content and to improve the soil chemical characteristics. However, the effect of biochar on soil is still not clear and the soil type and biochar composition should also play an important role. In this context, the main objective of this work was to evaluate the effect of biochar application on the organic carbon (C) content and on chemical characteristics of subtropical Cambisol. The field experiment was located at the State University of Centro ‐ Oeste in Irati, Brazil, and the soil was classified as an Haplic Cambisol (Embrapa, 1999). The applied biochar was composed mainly by fine residues ( 70% < 2mm ) of an eucalyptus biochar that was a waste of the local steel industry. In February 2010, four increasing doses of biochar were applied to the soil (T1 ‐ 0 t ha ‐ 1 ; T2 ‐ 10 t ha ‐ 1 ; T3 ‐ 20 t ha ‐ 1 and T4 ‐ 40 t ha ‐ 1 ) with four replicates. Soil samples were composed by three subsamples collected within each plot. Biochar was applied on the soil surface and thereafter it was incorporated into a 0 ‐ 10 cm soil depth with an harrow. Soil samples were collected in September 2011 at four soil depths: 0 ‐ 5; 5 ‐ 10; 10 ‐ 20 and 20 ‐ 30 cm. The samples were air dried and passed through a 2 mm sieve. Soil C and nitrogen (N) contents were determined by dry combustion and the soil characteristics assessed were: pH in water, available P, exchangeable K, Ca, Mg and Al, potential acidity (H + Al), cation exchange capacity (CEC), effective cation exchange capacity (ECEC) and base saturation (V%) (Tedesco et al., 1995). The mean values were compared using SAS software (Tukey 10%). The main alterations in soil characteristics were observed in the superficial depth (0 ‐ 5 cm) (Table 1) probably due to the permanence of the biochar fine particles at the soil surface. In this layer, the application of 40 t ha ‐ 1 of biochar (treatment T4) increased in 15.5 g kg ‐ 1 the C content in comparison to treatment T1. The treatments T2 and T3 also increased the C content, but the differences were not significant. N content was not affected by biochar application. The highest dose of biochar (treatment T4) promoted an increase of the C/N ratio from 12 to 16 at the 0 ‐ 5 cm depth. Treatment T4 also increased the soil pH value in comparison to treatment T1. In addition, the contents of available P, exchangeable K and Ca where higher under treatment T4 in comparison to treatment T1 (Table 1). In opposition, exchangeable Mg content, Al+H, V% and CEC were not altered by any treatment, but T4 increased the ECEC in 3.1 cmol c dm ‐ 3 in comparison to T1. The results observed are probably due the high C and ash (26,5%) contents of biochar. A contribution of the functional groups on the surface of the biochar to the ECEC should not be excluded (Sparkes & Stoutjesdijk, 2011). Our results indicate that after two years of biochar application an increase of soil organic carbon and a positive impact on the soil chemical characteristics at the soil surface were attained, but only with the highest tested dose (40 t ha ‐ 1 ) .Peer reviewe

Trichinella britovi etiological agent of sylvatic trichinellosis in the Republic of Guinea (West Africa) and a re-evaluation of geographical distribution for encapsulated species in Africa

In West Africa, Trichinella infection was documented in humans and animals from Senegal in the 1960s, and the biological characters of one isolate showed a lower infectivity to domestic pigs and rodents when compared with that of a Trichinella spiralis pig isolate from Europe. To identify the Trichinella species present in West Africa, a survey was conducted in a total of 160 wild animals in the Republic of Guinea. Three Viverridae, one true civet (Viverra civetta) and two African palm civets (Nandinia binotata) from the Fouta Djallon Massif, Pilimini Subprefecture, were found positive by artificial digestion of muscle samples. Trichinella larvae from these three viverrids were identified as Trichinella britovi and no difference was detected in three examined sequences from these African isolates and the reference strain of T. britovi from Europe, indicating common ancestry, an historically continuous geographic distribution, and recent isolation for African and European populations. The detection of T. britovi in West Africa modifies our knowledge about the distribution of encapsulated species of Trichinella in Africa. Thus, Trichinella nelsoni is now considered to have a distribution limited to the Eastern part of the Afrotropical region from Kenya to South Africa. This provides a plausible explanation for the presence of Trichinella T8 in Namibia and South Africa, and further suggests that T. britovi could be the Trichinella species circulating among wild animals of Northern Africa

Effect of biochar amendment on morphology, productivity and water relations of sunflower plants under non-irrigation conditions

páginas.-- 6 figuras.-- 2 tablas.-- 56 referencias.-- Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.catena.2016.07.037.Three biochars (B1: pine wood, B2: paper-sludge, B3: sewage-sludge) produced under controlled pyrolysis conditions and one produced in kilns (B4: grapevine wood) were used as organic ameliorants in a Calcic Cambisol, which represents a typical agricultural soil of the Mediterranean region. This field study was performed with plants of sunflower (Helianthus annuus L.) at the experimental station “La Hampa”, located in the Guadalquivir river valley (SW Spain). The soil was amended with doses equivalent to 1.5 and 15 t ha− 1 of the four biochars in two independent plantations. In addition, un-amended plots were prepared in both experiments for comparison purposes. The major goal of this study was the assessment of the effect of biochar amendment on the physiology and development of sunflower plants at field conditions. During most of the growing period plants of un-amended and amended plots showed no stress symptoms either by their appearance or by stress-sensitive biochemical parameters such as the stability of the photosystem II (QY). Biochar addition had no effect on seed germination. Addition of 1.5 t ha− 1 biochar did not significantly change the pH of the soil, its electrical conductivity (EC) or its water holding capacity (WHC). Concomitantly the plant development and plant biomass production remained unaltered. Amendments with 15 t ha− 1 slightly increased the WHC of the soil but showed no lasting impact on the soil pH. It stimulated plant growth and led to a greater leaf area, larger plant stems and wider inflorescences of the sunflower plants than those cultivated on the un-amended soil. At the end of the experiment, biochar amendment of soil caused no significant increase of the total biomass production excepting B4, the biochar with the lowest capacity of water retention, which exhibited the highest vegetative growth and seed production. The lack of rain during the last weeks caused a water shortage in the culture that produced greater QY loss in non-amended plants. Interestingly, better growth of amended plants during the drought period correlated with higher reduction of stomatal conductance, indicating that the greater water use efficiency is at the origin of the better crop performance of biochar-amended plants. This finding points to the agronomic relevance of biochar amendment of Mediterranean rain fed crops.The Marie Skłodowska-Curie actions of the European Union's FP7 People Programme (REA grant agreement no PCIG12-GA-2012-333784-Biocharisma project) and the Spanish Ministry of Economy and Competitiveness (MINECO) (project PCGL2012-37041) are thanked for the financial support of the present study. The Spanish Ministry of Education, Culture and Sport is acknowledged for funding the FPU fellowship (FPU 13/05831) of Marina Paneque, and the contract of Juan De Dios Franco-Navarro (AGL2009-08339/AGR). The European Biochar Network (Biochar as option for sustainable resource management-COST action TD1107) and Bodegas Torres (Spain) are acknowledged for providing the biochar samples. M. Velasco is gratefully acknowledged for her technical assistance at field.Peer reviewe