Residential biomass burning has been pointed out as one of the largest sources of fine particles in the global troposphere with serious impacts on air quality, climate and human health. Quantitative ...estimations of the contribution of this source to the atmospheric particulate matter levels are hard to obtain, because emission factors vary greatly with wood type, combustion equipment and operating conditions. Updated information should improve not only regional and global biomass burning emission inventories, but also the input for atmospheric models. In this work, an extensive tabulation of particulate matter emission factors obtained worldwide is presented and critically evaluated. Existing quantifications and the suitability of specific organic markers to assign the input of residential biomass combustion to the ambient carbonaceous aerosol are also discussed. Based on these organic markers or other tracers, estimates of the contribution of this sector to observed particulate levels by receptor models for different regions around the world are compiled. Key areas requiring future research are highlighted and briefly discussed.
•Residential biomass burning is a major source of fine particles worldwide.•This review provides detailed insights into the current status of PM emission factors.•The most important combustion conditions influencing PM emissions are discussed.•The main biomass burning organic tracers are critically reviewed.•Knowledge gaps and research opportunities are identified.
Seven fuels (four types of wood pellets and three agro-fuels) were tested in an automatic pellet stove (9.5 kWth) in order to determine emission factors (EFs) of gaseous compounds, such as carbon ...monoxide (CO), methane (CH4), formaldehyde (HCHO), and total organic carbon (TOC). Particulate matter (PM10) EFs and the corresponding chemical compositions for each fuel were also obtained. Samples were analysed for organic carbon (OC) and elemental carbon (EC), anhydrosugars and 57 chemical elements. The fuel type clearly affected the gaseous and particulate emissions. The CO EFs ranged from 90.9 ± 19.3 (pellets type IV) to 1480 ± 125 mg MJ−1 (olive pit). Wood pellets presented the lowest TOC emission factor among all fuels. HCHO and CH4 EFs ranged from 1.01 ± 0.11 to 36.9 ± 6.3 mg MJ−1 and from 0.23 ± 0.03 to 28.7 ± 5.7 mg MJ−1, respectively. Olive pit was the fuel with highest emissions of these volatile organic compounds. The PM10 EFs ranged from 26.6 ± 3.14 to 169 ± 23.6 mg MJ−1. The lowest PM10 emission factor was found for wood pellets type I (fuel with low ash content), whist the highest was observed during the combustion of an agricultural fuel (olive pit). The OC content of PM10 ranged from 8 wt.% (pellets type III) to 29 wt.% (olive pit). Variable EC particle mass fractions, ranging from 3 wt.% (olive pit) to 47 wt.% (shell of pine nuts), were also observed. The carbonaceous content of particulate matter was lower than that reported previously during the combustion of several wood fuels in traditional woodstoves and fireplaces. Levoglucosan was the most abundant anhydrosugar, comprising 0.02–3.03 wt.% of the particle mass. Mannosan and galactosan were not detected in almost all samples. Elements represented 11–32 wt.% of the PM10 mass emitted, showing great variability depending on the type of biofuel used.
•The highest emission factors were obtained for agro-fuels.•Organic carbon contributed no more than 30% of the PM10 mass.•Mannosan and galactosan were not detected in almost all samples.•Treated wood in pellets generated high contents of Pb, Zn and As in PM10.
Worldwide coal is still used for household heating purposes not only because it is available and cheap but also due to behavioural issues. Regional variability in fuels and combustion appliances make ...accurate emission estimates from this source hard to achieve. In the present study, gaseous (CO, VOCs, SO2 and NOX) and particulate matter (TSP) emission factors (EFs) were determined for Spanish household coal combustion covering three commercial coals and distinct combustion stages and mimicking usage patterns in real households. TSP samples were analysed to determine water-soluble inorganic ions, metal(loid)s, and organic and elemental carbon (OC and EC). Additionally, the morphology of the emitted particles was also characterised.
CO (3.43–169 g kg−1), NOX (1.29–6.00 g kg−1) and SO2 (8.96–22.3 g kg−1) EFs showed no trend regarding the combustion stage or coal type tested. On the other hand, VOC, TSP and EC EFs were higher for the ignition/devolatilisation combustion stage, regardless of the fuel tested. TSP EFs (0.085–1.08 g kg−1) increased with increasing coal volatile matter while the opposite trend was recorded for VOC emissions (0.045–3.39 gC kg−1).
TSP carbonaceous matter was dominated by EC while OC represented a small fraction of the particulate mass emitted (less than 8 %wt.). Inorganic compounds composed an important fraction of the TSP samples. Sulphate particulate mass fractions (8.66–22.9 %wt.) appeared to increase with coal S-content. Coal combustion released particles with diverse morphologies, including silicate-rich particles, ferro- and glassy-spheres. This study provides novel emission factors to update emission inventories of residential coal combustion. Additionally, detailed chemical profiles were obtained for source apportionment.
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•Gaseous and particulate emissions from the combustion of 3 types of coal were studied•Different gaseous and PM emissions were recorded over distinct combustion stages•TSP emissions appeared to be related to the coal volatile matter content•Sulphate was the major water-soluble inorganic ion for all the coal types studied•Coal combustion released silicate-rich particles, ferro- and glassy-spheres
Collusion is an illegal practice by which some competing companies secretly agree on the prices (bids) they will submit to a future auction. Worldwide, collusion is a pervasive phenomenon in public ...sector procurement. It undermines the benefits of a competitive marketplace and wastes taxpayers' money. More often than not, contracting authorities cannot identify non-competitive bids and frequently award contracts at higher prices than they would have in collusion's absence. This paper tests the accuracy of eleven Machine Learning (ML) algorithms for detecting collusion using collusive datasets obtained from Brazil, Italy, Japan, Switzerland and the United States. While the use of ML in public procurement remains largely unexplored, its potential use to identify collusion are promising. ML algorithms are quite information-intensive (they need a substantial number of historical auctions to be calibrated), but they are also highly flexible tools, producing reasonable detection rates even with a minimal amount of information.
•Existing collusion-detection models in public sector auctions are discussed.•Six datasets around the world are collected to get collusive and competitive auctions.•Eleven Machine Learning algorithms for detecting collusion are proposed.•These algorithms are tested over the six datasets to compare their detection accuracy.•Machine Learning algorithms develop successfully empirical models to detect collusion.
RESUMO Objetivo: as recomendações das decisões em Tumor Board (TB) deveriam ser acompanhadas para identificar barreiras que possam interferir na execução do melhor cuidado para o paciente decidido ...previamente. O objetivo do estudo é avaliar se a decisão de conduta em TB foi realizada em pacientes com tumores pancreáticos, o status de vida 90 dias após TB e analisar os motivos pelos quais a conduta não foi realizada. Métodos: estudo retrospectivo com pacientes com tumores de pâncreas, avaliados entre 2017 a 2019. Dados epidemiológicos, se a conduta de TB foi realizada, o motivo da não realização, o status de vida em 90 dias após decisão de TB e quantas vezes cada paciente foi discutido em reunião foram coletados. As variáveis categóricas foram comparadas pelo teste de qui-quadrado; variáveis numéricas foram apresentadas como médias e desvio padrão. Resultados: 111 casos, 95 pacientes, 86 (90,5%) com diagnóstico de câncer. Após 90 dias de TB, 83 pacientes (87,37%) permaneceram vivos, 9 pacientes (9,47%) faleceram e 3 (3,16%) perderam o seguimento. A conduta do TB não foi realizada em 12 (10,8%) dos casos e os motivos foram: 25% (3) por perda de seguimento, 8,33% (1) por recusa do paciente e 66,67% (8) devido à piora clínica. Os casos de pacientes com metástases tiveram menor execução de conduta de TB (p=0,006). Conclusões: a conduta do TB é realizada na maior parte dos casos e o motivo mais evidente para o não cumprimento das condutas é a piora clínica do paciente.
ABSTRACT Objective: the recommendations of the decisions made by the Tumor Board (TB) should be followed to identify barriers that may interfere with the execution of the previously decided, best care for the patient. The aim of this study is to assess whether the TB conduct decision was performed in patients with pancreatic tumors, their life status 90 days after the TB decision, and to analyze the reasons why the conduct was not performed. Methods: we conducted a retrospective study with patients with pancreas tumors, evaluated between 2017 and 2019. We collected data on epidemiological status, whether the TB procedure was performed, the reason for not performing it, life status 90 days after the TB decision, and how many times each patient was discussed at a meeting. We compared categorical variables using the chi square test, numerical variables were presented as means and standard deviation. Results: we studied 111 session cases, in 95 patients, 86 (90.5%) diagnosed with cancer. After 90 days of TB, 83 patients (87.37%) remained alive, 9 had (9.47%) died, and 3 (3.16%) were lost to follow-up. The TB decision was not observed in 12 (10.8%) cases and the reasons were: 25% (3) for loss of follow-up, 8.33% (1) for patient refusal, and 66.67% (8) due to clinical worsening. The cases of patients with metastases had a lower rate of TB conduct compliance (p=0.006). Conclusions: the TB conduct was performed in most cases and the most evident reason for non-compliance with the conducts is the patient’s clinical worsening.
Little is known about how the virulence of a human pathogen varies in the environment it shares with its vector. This study focused on whether the virulence of Trypanosoma cruzi (Trypanosomatida: ...Trypanosomatidae), the causal agent of Chagas' disease, is related to altitude. Accordingly, Triatoma dimidiata (Hemiptera: Reduviidae) specimens were collected at three different altitudes (300, 700 and 1400 m a.s.l.) in Chiapas, Mexico. The parasite was then isolated to infect uninfected T. dimidiata from the same altitudes, as well as female CD‐1 mice. The response variables were phenoloxidase (PO) activity, a key insect immune response, parasitaemia in mice, and amastigote numbers in the heart, oesophagus, gastrocnemius and brain of the rodents. The highest levels of PO activity, parasitaemia and amastigotes were found for Tryp. cruzi isolates sourced from 700 m a.s.l., particularly in the mouse brain. A polymerase chain reaction‐based analysis indicated that all Tryp. cruzi isolates belonged to a Tryp. cruzi I lineage. Thus, Tryp. cruzi from 700 m a.s.l. may be more dangerous than sources at other altitudes. At this altitude, T. dimidiata is more common, apparently because the conditions are more beneficial to its development. Control strategies should focus activity at altitudes around 700 m a.s.l., at least in relation to the region of the present study sites.
Proper development of compact myocardium, coronary vessels, and Purkinje fibers depends on the presence of epicardium-derived cells (EPDCs) in embryonic myocardium. We hypothesized that adult human ...EPDCs might partly reactivate their embryonic program when transplanted into ischemic myocardium and improve cardiac performance after myocardial infarction.
EPDCs were isolated from human adult atrial tissue. Myocardial infarction was created in immunodeficient mice, followed by intramyocardial injection of 4x10(5) enhanced green fluorescent protein-labeled EPDCs (2-week survival, n=22; 6-week survival, n=15) or culture medium (n=24 and n=18, respectively). Left ventricular function was assessed with a 9.4T animal MRI unit. Ejection fraction was similar between groups on day 2 but was significantly higher in the EPDC-injected group at 2 weeks (short term), as well as after long-term survival at 6 weeks. End-systolic and end-diastolic volumes were significantly smaller in the EPDC-injected group than in the medium-injected group at all ages evaluated. At 2 weeks, vascularization was significantly increased in the EPDC-treated group, as was wall thickness, a development that might be explained by augmented DNA-damage repair activity in the infarcted area. Immunohistochemical analysis showed massive engraftment of injected EPDCs at 2 weeks, with expression of alpha-smooth muscle actin, von Willebrand factor, sarcoplasmic reticulum Ca2+-ATPase, and voltage-gated sodium channel (alpha-subunit; SCN5a). EPDCs were negative for cardiomyocyte markers. At 6-weeks survival, wall thickness was still increased, but only a few EPDCs could be detected.
After transplantation into ischemic myocardium, adult human EPDCs preserve cardiac function and attenuate ventricular remodeling. Autologous human EPDCs are promising candidates for clinical application in infarcted hearts.
Abstract There are no guava cultivars resistant to the Meloidogyne enterolobii; for this reason, genetic breeding has been performed by introgressing genes into the current cultivars through ...interspecific hybridization. We used 33 microsatellite markers for the genetic-molecular characterization of segregating populations of Psidium resistant to M. enterolobii, aiming at selection within and between populations for generation advancement in the guava breeding program. The average number of alleles per locus ranged from 1.60 to 2.09. Populations 1 (P. guineense × P. cattleyanum) and 5 (P. guajava × P. cattleyanum) obtained the greatest genetic diversity, which can be confirmed by the higher observed-heterozygosity values (0.422 and 0.312, respectively). Bayesian analysis showed that the populations were subdivided into three groups, agreeing with the number of groups observed by Nei’s genetic distance. The population obtained from the P. guineense × P. cattleyanum cross differed from the others with a clear structuring, whereas the P. guajava × P. cattleyanum and P. cattleyanum × P. guineense populations were the most similar between each other. The SSR markers were efficient in discriminating the populations, and individual 80 may be employed in future crosses with guava, allowing generation advancement in the guava breeding program aimed at resistance to M. enterolobii.
Wood combustion experiments were carried out to determine the effect of ignition technique, biomass load and cleavage, as well as secondary air supply, on carbon monoxide (CO), total hydrocarbon ...(THC), particulate matter (PM10) and particle number emissions from a woodstove. Wood from two typical tree species in the Iberian Peninsula was selected: pine (Pinus pinaster) and beech (Fagus sylvatica). The highest CO and total hydrocarbon emission factors (EFs) were observed, respectively, for pine and beech, for high and low fuel loads. The highest PM10 EF was recorded for the operation with low loads for both woods. Secondary air supply produced the lowest PM10 emission factors. The top ignition can decrease the PM10 EF to less than half when compared with the common technique of lighting from the bottom. The lowest particle number emission factors were observed when operating with high loads of split beech logs and when using secondary air supply during the combustion of pine. Regarding particle number distributions, the highest geometric mean diameter (Dg), for both woods, were observed when operating with high loads (with split and non-split wood).
•Operating conditions have great influence on emissions.•Top ignition can reduce by 50% the PM10 emissions in relation to bottom lighting.•Secondary air supply produced the lowest PM10 emission factors.•Highest Dg was observed for operation with high loads.
Declines in insect pollinators have been linked to a range of causative factors such as disease, loss of habitats, the quality and availability of food, and exposure to pesticides. Here, we analysed ...an extensive dataset generated from pesticide screening of foraging insects, pollen-nectar stores/beebread, pollen and ingested nectar across three species of bees collected at 128 European sites set in two types of crop. In this paper, we aimed to (i) derive a new index to summarise key aspects of complex pesticide exposure data and (ii) understand the links between pesticide exposures depicted by the different matrices, bee species and apple orchards versus oilseed rape crops. We found that summary indices were highly correlated with the number of pesticides detected in the related matrix but not with which pesticides were present. Matrices collected from apple orchards generally contained a higher number of pesticides (7.6 pesticides per site) than matrices from sites collected from oilseed rape crops (3.5 pesticides), with fungicides being highly represented in apple crops. A greater number of pesticides were found in pollen-nectar stores/beebread and pollen matrices compared with nectar and bee body matrices. Our results show that for a complete assessment of pollinator pesticide exposure, it is necessary to consider several different exposure routes and multiple species of bees across different agricultural systems.
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•We use new indices to summarise big datasets on pesticide exposure of three species of bees•Novel indices are calculated using Item Response Theory (IRT) models•The indices are linked to the number of pesticides rather than the active ingredients•Matrices collected from apple orchards are exposed to a higher number of pesticides compared to oilseed rape crop sites•Pollen related matrices contained more pesticides than were found in nectar and on the bees themselves
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