Economic Growth and Regional Integration in Mexico

In this paper we examine the regional structure of output growth, volatility and prosperity in Mexico, focusing in particular on the degree of integration between both the regions and the individual states of the country. The results suggest that there is a high degree of similarity across the regions in the responses to domestic and international shocks affecting the economy, but there are also significant differences across the individual states within each region. We identify a positive relationship between output growth and volatility, but the relationship between growth and regional disparities appears to be negative, suggesting that higher (lower) growth is generally associated with lower (higher) regional dispersion in per capita GDP levels

Updated opacities from the opacity project

Using the code autostructure, extensive calculations of inner-shell atomic data have been made for the chemical elements He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni. The results are used to obtain updated opacities from the Opacity Project (OP). A number of other improvements on earlier work have also been included. Rosseland-mean opacities from the OP are compared with those from OPAL. Differences of 5-10 per cent occur. The OP gives the 'Z-bump', at log(T) 5.2, to be shifted to slightly higher temperatures. The opacities from the OP, as functions of temperature and density, are smoother than those from OPAL. The accuracy of the integrations used to obtain mean opacities can depend on the frequency mesh used. Tests involving variation of the numbers of frequency points show that for typical chemical mixtures the OP integrations are numerically correct to within 0.1 per cent. The accuracy of the interpolations used to obtain mean opacities for any required values of temperature and density depends on the temperature-density meshes used. Extensive tests show that, for all cases of practical interest, the OP interpolations give results correct to better than 1 per cent. Prior to a number of recent investigations which have indicated a need for downward revisions in the solar abundances of oxygen and other elements, there was good agreement between properties of the Sun deduced from helioseismology and from stellar evolution models calculated using OPAL opacities. The revisions destroy that agreement. In a recent paper, Bahcall et al. argue that the agreement would be restored if opacities for the regions of the Sun with 2 × 106T 5 × 106 K (0.7-0.4 R) were larger than those given by OPAL by about 10 per cent. In the region concerned, the present results from the OP do not differ from those of OPAL by more than 2.5 per cent

Analytical Expressions for Radiative Opacities of Low Z Plasmas

In this work we obtain analytical expressions for the radiative opacity of several low Z plasmas (He, Li, Be, and B) in a wide range of temperatures and densities. These formulas are obtained by fitting the proposed expression to mean opacities data calculated by using the code ABAKO/ RAPCAL. This code computes the radiative properties of plasmas, both in LTE and NLTE conditions, under the detailed-level-accounting approach. It has been successfully validated in the range of interest in previous works

Deepening the uncertainty dimension of environmental Life Cycle Assessment: addressing choice, future and interpretation uncertainties.

LCA has become an important method to study environmental impacts of human activities. Still, there are several methodological issues in LCA that can adversely affect the results reliability. Three of these issues relate to a) allocation, b) the representation of the time dimension and c) the interpretation of results in LCA. Uncertainties play a fundamental and underlying role for these issues. It is widely-agreed that correctly dealing with these different uncertainty sources is a vital step towards increasing the usefulness and reliability of LCA results. Practical ways to deal with uncertainty are needed. The aim of this thesis is to deepen the understanding of the uncertainty dimension of current LCA. By means of addressing different sources of uncertainty not yet addressed, with new methods, a clearer picture of the implications of different sources of uncertainty in LCA is provided. This thesis departed from broad domains of uncertainty including risk, uncertainty as conventionally described, ignorance and indeterminacies. The selected sources of uncertainty are in the domains of risk and conventional uncertainty i.e. those due to incomplete scientific knowledge and that are to some extent quantifiable. This does not mean that all can be known or quantified as ignorance and indeterminacies exist. Industrial Ecolog

Wastewater treatment plant as microplastics release source - Quantification and identification techniques

[EN] The high presence of microplastics (MPs) in different sizes, materials and concentrations in the aquatic environment is a global concern due to their potential physically and chemically harm to aquatic organisms including mammals. Furthermore, the bioaccumulation of these compounds is leading to their ingestion by humans through the consumption of sea food and even through the terrestrial food chain. Even though conventional wastewater treatment plants are capable of eliminating more than 90% of the influent MPs, these systems are still the main source of MPs introduction in the environment due to the high volumes of effluents generated and returned to the environment. The amount of MPs dumped by WWTP is influenced by the configuration of the WWTP, population served and influent flow. Thus, the average of MP/L disposed vary widely depending on the region. In addition to MPs disposed in water bodies, more than 80% of these emerging contaminants, which enter the WWTP, are retained in biosolids that can be applied as fertilizers, representing a potential source of soil contamination. Due to the continuous disposal of MPs in the environment by effluent treatment systems and their polluting potential, separation and identification techniques have been assessed by several researchers, but unfortunately, there are no standard protocols for them. Aiming to provide insight about the relevance of studying the WWTP as source of MPs, this review summarizes the currently methodologies used to classify and identify them.Bretas Alvim, C.; Mendoza Roca, JA.; Bes-Piá, M. (2020). Wastewater treatment plant as microplastics release source - Quantification and identification techniques. Journal of Environmental Management. 255:1-11. https://doi.org/10.1016/j.jenvman.2019.109739S111255Araujo, C. F., Nolasco, M. M., Ribeiro, A. M. P., & Ribeiro-Claro, P. J. A. (2018). Identification of microplastics using Raman spectroscopy: Latest developments and future prospects. Water Research, 142, 426-440. doi:10.1016/j.watres.2018.05.060Auta, H. S., Emenike, C. ., & Fauziah, S. . (2017). Distribution and importance of microplastics in the marine environment: A review of the sources, fate, effects, and potential solutions. Environment International, 102, 165-176. doi:10.1016/j.envint.2017.02.013Babuponnusami, A., & Muthukumar, K. (2014). A review on Fenton and improvements to the Fenton process for wastewater treatment. Journal of Environmental Chemical Engineering, 2(1), 557-572. doi:10.1016/j.jece.2013.10.011Bautista, P., Mohedano, A. F., Casas, J. A., Zazo, J. A., & Rodriguez, J. J. (2008). An overview of the application of Fenton oxidation to industrial wastewaters treatment. Journal of Chemical Technology & Biotechnology, 83(10), 1323-1338. doi:10.1002/jctb.1988Browne, M. A., Crump, P., Niven, S. J., Teuten, E., Tonkin, A., Galloway, T., & Thompson, R. (2011). Accumulation of Microplastic on Shorelines Woldwide: Sources and Sinks. Environmental Science & Technology, 45(21), 9175-9179. doi:10.1021/es201811sCarr, S. A., Liu, J., & Tesoro, A. G. (2016). Transport and fate of microplastic particles in wastewater treatment plants. Water Research, 91, 174-182. doi:10.1016/j.watres.2016.01.002Catarino, A. I., Thompson, R., Sanderson, W., & Henry, T. B. (2016). Development and optimization of a standard method for extraction of microplastics in mussels by enzyme digestion of soft tissues. Environmental Toxicology and Chemistry, 36(4), 947-951. doi:10.1002/etc.3608Chang, M. (2015). Reducing microplastics from facial exfoliating cleansers in wastewater through treatment versus consumer product decisions. Marine Pollution Bulletin, 101(1), 330-333. doi:10.1016/j.marpolbul.2015.10.074Cole, M., Lindeque, P., Fileman, E., Halsband, C., Goodhead, R., Moger, J., & Galloway, T. S. (2013). Microplastic Ingestion by Zooplankton. Environmental Science & Technology, 47(12), 6646-6655. doi:10.1021/es400663fCourtene-Jones, W., Quinn, B., Murphy, F., Gary, S. F., & Narayanaswamy, B. E. (2017). Optimisation of enzymatic digestion and validation of specimen preservation methods for the analysis of ingested microplastics. Analytical Methods, 9(9), 1437-1445. doi:10.1039/c6ay02343fDevi, P., Das, U., & Dalai, A. K. (2016). In-situ chemical oxidation: Principle and applications of peroxide and persulfate treatments in wastewater systems. Science of The Total Environment, 571, 643-657. doi:10.1016/j.scitotenv.2016.07.032Duemichen, E., Braun, U., Senz, R., Fabian, G., & Sturm, H. (2014). Assessment of a new method for the analysis of decomposition gases of polymers by a combining thermogravimetric solid-phase extraction and thermal desorption gas chromatography mass spectrometry. Journal of Chromatography A, 1354, 117-128. doi:10.1016/j.chroma.2014.05.057Dümichen, E., Eisentraut, P., Bannick, C. G., Barthel, A.-K., Senz, R., & Braun, U. (2017). Fast identification of microplastics in complex environmental samples by a thermal degradation method. Chemosphere, 174, 572-584. doi:10.1016/j.chemosphere.2017.02.010Dyachenko, A., Mitchell, J., & Arsem, N. (2017). Extraction and identification of microplastic particles from secondary wastewater treatment plant (WWTP) effluent. Analytical Methods, 9(9), 1412-1418. doi:10.1039/c6ay02397eElert, A. M., Becker, R., Duemichen, E., Eisentraut, P., Falkenhagen, J., Sturm, H., & Braun, U. (2017). Comparison of different methods for MP detection: What can we learn from them, and why asking the right question before measurements matters? Environmental Pollution, 231, 1256-1264. doi:10.1016/j.envpol.2017.08.074Enders, K., Lenz, R., Beer, S., & Stedmon, C. A. (2016). Extraction of microplastic from biota: recommended acidic digestion destroys common plastic polymers. ICES Journal of Marine Science, 74(1), 326-331. doi:10.1093/icesjms/fsw173Erni-Cassola, G., Gibson, M. I., Thompson, R. C., & Christie-Oleza, J. A. (2017). Lost, but Found with Nile Red: A Novel Method for Detecting and Quantifying Small Microplastics (1 mm to 20 μm) in Environmental Samples. Environmental Science & Technology, 51(23), 13641-13648. doi:10.1021/acs.est.7b04512De Falco, F., Gullo, M. P., Gentile, G., Di Pace, E., Cocca, M., Gelabert, L., … Avella, M. (2018). Evaluation of microplastic release caused by textile washing processes of synthetic fabrics. Environmental Pollution, 236, 916-925. doi:10.1016/j.envpol.2017.10.057Fendall, L. S., & Sewell, M. A. (2009). Contributing to marine pollution by washing your face: Microplastics in facial cleansers. Marine Pollution Bulletin, 58(8), 1225-1228. doi:10.1016/j.marpolbul.2009.04.025Fischer, M., & Scholz-Böttcher, B. M. (2017). Simultaneous Trace Identification and Quantification of Common Types of Microplastics in Environmental Samples by Pyrolysis-Gas Chromatography–Mass Spectrometry. Environmental Science & Technology, 51(9), 5052-5060. doi:10.1021/acs.est.6b06362Fries, E., Dekiff, J. H., Willmeyer, J., Nuelle, M.-T., Ebert, M., & Remy, D. (2013). Identification of polymer types and additives in marine microplastic particles using pyrolysis-GC/MS and scanning electron microscopy. Environmental Science: Processes & Impacts, 15(10), 1949. doi:10.1039/c3em00214dGies, E. A., LeNoble, J. L., Noël, M., Etemadifar, A., Bishay, F., Hall, E. R., & Ross, P. S. (2018). Retention of microplastics in a major secondary wastewater treatment plant in Vancouver, Canada. Marine Pollution Bulletin, 133, 553-561. doi:10.1016/j.marpolbul.2018.06.006Guerranti, C., Martellini, T., Perra, G., Scopetani, C., & Cincinelli, A. (2019). Microplastics in cosmetics: Environmental issues and needs for global bans. Environmental Toxicology and Pharmacology, 68, 75-79. doi:10.1016/j.etap.2019.03.007Gündoğdu, S., Çevik, C., Güzel, E., & Kilercioğlu, S. (2018). Microplastics in municipal wastewater treatment plants in Turkey: a comparison of the influent and secondary effluent concentrations. Environmental Monitoring and Assessment, 190(11). doi:10.1007/s10661-018-7010-yHanvey, J. S., Lewis, P. J., Lavers, J. L., Crosbie, N. D., Pozo, K., & Clarke, B. O. (2017). A review of analytical techniques for quantifying microplastics in sediments. Analytical Methods, 9(9), 1369-1383. doi:10.1039/c6ay02707eHe, D., Luo, Y., Lu, S., Liu, M., Song, Y., & Lei, L. (2018). Microplastics in soils: Analytical methods, pollution characteristics and ecological risks. TrAC Trends in Analytical Chemistry, 109, 163-172. doi:10.1016/j.trac.2018.10.006Hidalgo-Ruz, V., Gutow, L., Thompson, R. C., & Thiel, M. (2012). Microplastics in the Marine Environment: A Review of the Methods Used for Identification and Quantification. Environmental Science & Technology, 46(6), 3060-3075. doi:10.1021/es2031505Hidayaturrahman, H., & Lee, T.-G. (2019). A study on characteristics of microplastic in wastewater of South Korea: Identification, quantification, and fate of microplastics during treatment process. Marine Pollution Bulletin, 146, 696-702. doi:10.1016/j.marpolbul.2019.06.071Huerta Lwanga, E., Mendoza Vega, J., Ku Quej, V., Chi, J. de los A., Sanchez del Cid, L., Chi, C., … Geissen, V. (2017). Field evidence for transfer of plastic debris along a terrestrial food chain. Scientific Reports, 7(1). doi:10.1038/s41598-017-14588-2Hurley, R. R., Lusher, A. L., Olsen, M., & Nizzetto, L. (2018). Validation of a Method for Extracting Microplastics from Complex, Organic-Rich, Environmental Matrices. Environmental Science & Technology, 52(13), 7409-7417. doi:10.1021/acs.est.8b01517Jochem, G., & Lehnert, R. J. (2002). On the potential of Raman microscopy for the forensic analysis of coloured textile fibres. Science & Justice, 42(4), 215-221. doi:10.1016/s1355-0306(02)71831-5Kalčíková, G., Alič, B., Skalar, T., Bundschuh, M., & Gotvajn, A. Ž. (2017). Wastewater treatment plant effluents as source of cosmetic polyethylene microbeads to freshwater. Chemosphere, 188, 25-31. doi:10.1016/j.chemosphere.2017.08.131Käppler, A., Fischer, D., Oberbeckmann, S., Schernewski, G., Labrenz, M., Eichhorn, K.-J., & Voit, B. (2016). Analysis of environmental microplastics by vibrational microspectroscopy: FTIR, Raman or both? Analytical and Bioanalytical Chemistry, 408(29), 8377-8391. doi:10.1007/s00216-016-9956-3Käppler, A., Fischer, M., Scholz-Böttcher, B. M., Oberbeckmann, S., Labrenz, M., Fischer, D., … Voit, B. (2018). Comparison of μ-ATR-FTIR spectroscopy and py-GCMS as identification tools for microplastic particles and fibers isolated from river sediments. Analytical and Bioanalytical Chemistry, 410(21), 5313-5327. doi:10.1007/s00216-018-1185-5Lares, M., Ncibi, M. C., Sillanpää, M., & Sillanpää, M. (2018). Occurrence, identification and removal of microplastic particles and fibers in conventional activated sludge process and advanced MBR technology. Water Research, 133, 236-246. doi:10.1016/j.watres.2018.01.049Lei, K., Qiao, F., Liu, Q., Wei, Z., Qi, H., Cui, S., … An, L. (2017). Microplastics releasing from personal care and cosmetic products in China. Marine Pollution Bulletin, 123(1-2), 122-126. doi:10.1016/j.marpolbul.2017.09.016Lenz, R., Enders, K., Stedmon, C. A., Mackenzie, D. M. A., & Nielsen, T. G. (2015). A critical assessment of visual identification of marine microplastic using Raman spectroscopy for analysis improvement. Marine Pollution Bulletin, 100(1), 82-91. doi:10.1016/j.marpolbul.2015.09.026Leslie, H. A., Brandsma, S. H., van Velzen, M. J. M., & Vethaak, A. D. (2017). Microplastics en route: Field measurements in the Dutch river delta and Amsterdam canals, wastewater treatment plants, North Sea sediments and biota. Environment International, 101, 133-142. doi:10.1016/j.envint.2017.01.018Li, J., Liu, H., & Paul Chen, J. (2018). Microplastics in freshwater systems: A review on occurrence, environmental effects, and methods for microplastics detection. Water Research, 137, 362-374. doi:10.1016/j.watres.2017.12.056Li, X., Chen, L., Mei, Q., Dong, B., Dai, X., Ding, G., & Zeng, E. Y. (2018). Microplastics in sewage sludge from the wastewater treatment plants in China. Water Research, 142, 75-85. doi:10.1016/j.watres.2018.05.034Liu, X., Yuan, W., Di, M., Li, Z., & Wang, J. (2019). Transfer and fate of microplastics during the conventional activated sludge process in one wastewater treatment plant of China. Chemical Engineering Journal, 362, 176-182. doi:10.1016/j.cej.2019.01.033Löder, M. G. J., Imhof, H. K., Ladehoff, M., Löschel, L. A., Lorenz, C., Mintenig, S., … Gerdts, G. (2017). Enzymatic Purification of Microplastics in Environmental Samples. Environmental Science & Technology, 51(24), 14283-14292. doi:10.1021/acs.est.7b03055Long, Z., Pan, Z., Wang, W., Ren, J., Yu, X., Lin, L., … Jin, X. (2019). Microplastic abundance, characteristics, and removal in wastewater treatment plants in a coastal city of China. Water Research, 155, 255-265. doi:10.1016/j.watres.2019.02.028Maes, T., Jessop, R., Wellner, N., Haupt, K., & Mayes, A. G. (2017). A rapid-screening approach to detect and quantify microplastics based on fluorescent tagging with Nile Red. Scientific Reports, 7(1). doi:10.1038/srep44501Magni, S., Binelli, A., Pittura, L., Avio, C. G., Della Torre, C., Parenti, C. C., … Regoli, F. (2019). The fate of microplastics in an Italian Wastewater Treatment Plant. Science of The Total Environment, 652, 602-610. doi:10.1016/j.scitotenv.2018.10.269Mahon, A. M., O’Connell, B., Healy, M. G., O’Connor, I., Officer, R., Nash, R., & Morrison, L. (2016). Microplastics in Sewage Sludge: Effects of Treatment. Environmental Science & Technology, 51(2), 810-818. doi:10.1021/acs.est.6b04048Massonnet, G., Buzzini, P., Monard, F., Jochem, G., Fido, L., Bell, S., … Blumer, A. (2012). Raman spectroscopy and microspectrophotometry of reactive dyes on cotton fibres: Analysis and detection limits. Forensic Science International, 222(1-3), 200-207. doi:10.1016/j.forsciint.2012.05.025Mato, Y., Isobe, T., Takada, H., Kanehiro, H., Ohtake, C., & Kaminuma, T. (2000). Plastic Resin Pellets as a Transport Medium for Toxic Chemicals in the Marine Environment. Environmental Science & Technology, 35(2), 318-324. doi:10.1021/es0010498Michielssen, M. R., Michielssen, E. R., Ni, J., & Duhaime, M. B. (2016). Fate of microplastics and other small anthropogenic litter (SAL) in wastewater treatment plants depends on unit processes employed. Environmental Science: Water Research & Technology, 2(6), 1064-1073. doi:10.1039/c6ew00207bMintenig, S. M., Int-Veen, I., Löder, M. G. J., Primpke, S., & Gerdts, G. (2017). Identification of microplastic in effluents of waste water treatment plants using focal plane array-based micro-Fourier-transform infrared imaging. Water Research, 108, 365-372. doi:10.1016/j.watres.2016.11.015Mohapatra, D. P., Cledón, M., Brar, S. K., & Surampalli, R. Y. (2016). Application of Wastewater and Biosolids in Soil: Occurrence and Fate of Emerging Contaminants. Water, Air, & Soil Pollution, 227(3). doi:10.1007/s11270-016-2768-4Munno, K., Helm, P. A., Jackson, D. A., Rochman, C., & Sims, A. (2017). Impacts of temperature and selected chemical digestion methods on microplastic particles. Environmental Toxicology and Chemistry, 37(1), 91-98. doi:10.1002/etc.3935Murphy, F., Ewins, C., Carbonnier, F., & Quinn, B. (2016). Wastewater Treatment Works (WwTW) as a Source of Microplastics in the Aquatic Environment. Environmental Science & Technology, 50(11), 5800-5808. doi:10.1021/acs.est.5b05416Naidoo, T., Goordiyal, K., & Glassom, D. (2017). Are Nitric Acid (HNO3) Digestions Efficient in Isolating Microplastics from Juvenile Fish? Water, Air, & Soil Pollution, 228(12). doi:10.1007/s11270-017-3654-4Napper, I. E., Bakir, A., Rowland, S. J., & Thompson, R. C. (2015). Characterisation, quantity and sorptive properties of microplastics extracted from cosmetics. Marine Pollution Bulletin, 99(1-2), 178-185. doi:10.1016/j.marpolbul.2015.07.029Ng, E.-L., Huerta Lwanga, E., Eldridge, S. M., Johnston, P., Hu, H.-W., Geissen, V., & Chen, D. (2018). An overview of microplastic and nanoplastic pollution in agroecosystems. Science of The Total Environment, 627, 1377-1388. doi:10.1016/j.scitotenv.2018.01.341Nizzetto, L., Futter, M., & Langaas, S. (2016). Are Agricultural Soils Dumps for Microplastics of Urban Origin? Environmental Science & Technology, 50(20), 10777-10779. doi:10.1021/acs.est.6b04140Nuelle, M.-T., Dekiff, J. H., Remy, D., & Fries, E. (2014). A new analytical approach for monitoring microplastics in marine sediments. Environmental Pollution, 184, 161-169. doi:10.1016/j.envpol.2013.07.027Prata, J. C., da Costa, J. P., Duarte, A. C., & Rocha-Santos, T. (2019). Methods for sampling and detection of microplastics in water and sediment: A critical review. TrAC Trends in Analytical Chemistry, 110, 150-159. doi:10.1016/j.trac.2018.10.029Qiu, Q., Tan, Z., Wang, J., Peng, J., Li, M., & Zhan, Z. (2016). Extraction, enumeration and identification methods for monitoring microplastics in the environment. Estuarine, Coastal and Shelf Science, 176, 102-109. doi:10.1016/j.ecss.2016.04.012Rios Mendoza, L. M., Karapanagioti, H., & Álvarez, N. R. (2018). Micro(nanoplastics) in the marine environment: Current knowledge and gaps. Current Opinion in Environmental Science & Health, 1, 47-51. doi:10.1016/j.coesh.2017.11.004Rocha-Santos, T. A. P. (2018). Editorial overview: Micro and nano-plastics. Current Opinion in Environmental Science & Health, 1, 52-54. doi:10.1016/j.coesh.2018.01.003Rocha-Santos, T., & Duarte, A. C. (2015). A critical overview of the analytical approaches to the occurrence, the fate and the behavior of microplastics in the environment. TrAC Trends in Analytical Chemistry, 65, 47-53. doi:10.1016/j.trac.2014.10.011Simon, M., van Alst, N., & Vollertsen, J. (2018). Quantification of microplastic mass and removal rates at wastewater treatment plants applying Focal Plane Array (FPA)-based Fourier Transform Infrared (FT-IR) imaging. Water Research, 142, 1-9. doi:10.1016/j.watres.2018.05.019Sujathan, S., Kniggendorf, A.-K., Kumar, A., Roth, B., Rosenwinkel, K.-H., & Nogueira, R. (2017). Heat and Bleach: A Cost-Efficient Method for Extracting Microplastics from Return Activated Sludge. Archives of Environmental Contamination and Toxicology, 73(4), 641-648. doi:10.1007/s00244-017-0415-8Tagg, A. S., Harrison, J. P., Ju-Nam, Y., Sapp, M., Bradley, E. L., Sinclair, C. J., & Ojeda, J. J. (2017). Fenton’s reagent for the rapid and efficient isolation of microplastics from wastewater. Chemical Communications, 53(2), 372-375. doi:10.1039/c6cc08798aTalvitie, J., Heinonen, M., Pääkkönen, J.-P., Vahtera, E., Mikola, A., Setälä, O., & Vahala, R. (2015). Do wastewater treatment plants act as a potential point source of microplastics? Preliminary study in the coastal Gulf of Finland, Baltic Sea. Water Science and Technology, 72(9), 1495-1504. doi:10.2166/wst.2015.360Talvitie, J., Mikola, A., Koistinen, A., & Setälä, O. (2017). Solutions to microplastic pollution – Removal of microplastics from wastewater effluent with advanced wastewater treatment technologies. Water Research, 123, 401-407. doi:10.1016/j.watres.2017.07.005Talvitie, J., Mikola, A., Setälä, O., Heinonen, M., & Koistinen, A. (2017). How well is microlitter purified from wastewater? – A detailed study on the stepwise removal of microlitter in a tertiary level wastewater treatment plant. Water Research, 109, 164-172. doi:10.1016/j.watres.2016.11.046Von Friesen, L. W., Granberg, M. E., Hassellöv, M., Gabrielsen, G. W., & Magnusson, K. (2019). An efficient and gentle enzymatic digestion protocol for the extraction of microplastics from bivalve tissue. Marine Pollution Bulletin, 142, 129-134. doi:10.1016/j.marpolbul.2019.03.016Waller, C. L., Griffiths, H. J., Waluda, C. M., Thorpe, S. E., Loaiza, I., Moreno, B., … Hughes, K. A. (2017). Microplastics in the Antarctic marine system: An emerging area of research. Science of The Total Environment, 598, 220-227. doi:10.1016/j.scitotenv.2017.03.283Wang, W., & Wang, J. (2018). Investigation of microplastics in aquatic environments: An overview of the methods used, from field sampling to laboratory analysis. TrAC Trends in Analytical Chemistry, 108, 195-202. doi:10.1016/j.trac.2018.08.026Ziajahromi, S., Neale, P. A., Rintoul, L., & Leusch, F. D. L. (2017). Wastewater treatment plants as a pathway for microplastics: Development of a new approach to sample wastewater-based microplastics. Water Research, 112, 93-99. doi:10.1016/j.watres.2017.01.04

The role of the operating parameters of SBR systems on the SMP production and on membrane fouling reduction

[EN] In this work, six identical laboratory SBRs treating simulated wastewater were operated in parallel studying the effect of three food-to-microorganisms ratio (F/M ratio; 0.20, 0.35 and 0.50 kg COD¿kg MLSS-1¿d-1), two hydraulic retention times (HRT; 24 and 16 h) and two values of number of cycles per day (3 and 6). Influence of these operational parameters on the SMPs production and reactor performance, were studied. Results indicated that the highest F/M ratio, HRT and cycles/day produced 72.7% more of SMP. In a second experimental series, biological process yielding the maximal and the minimal SMPs production were replicated and both mixed liquors (ML) and treated effluents were ultrafiltrated. The flux decay in the conditions of minimum and maximum SMPs production were 52% and 72%, when the SBRs effluents were ultrafiltrated while no significant differences in the ultrafiltration of ML were found. In terms of permeability recovery, this was lower for the case of the ML (73% and 49% of initial permeability recovered for effluent and ML ultrafiltration, respectively).This work was supported by the Spanish Ministerio de Economia y Competitividad (CTM2014-54546-P).Ferrer-Polonio, E.; White, K.; Mendoza Roca, JA.; Bes-Piá, M. (2018). The role of the operating parameters of SBR systems on the SMP production and on membrane fouling reduction. Journal of Environmental Management. 228:205-212. https://doi.org/10.1016/j.jenvman.2018.09.036S20521222

Antispasmodic effects and action mechanism of essential oil of Chrysactinia mexicana A. Gray on rabbit ileum

The Chrysactinia mexicana A. Gray (C. mexicana) plant is used in folk medicine to treat fever and rheumatism; it is used as a diuretic, antispasmodic; and it is used for its aphrodisiac properties. This study investigates the effects of the essential oil of C. mexicana (EOCM) on the contractility of rabbit ileum and the mechanisms of action involved. Muscle contractility studies in vitro in an organ bath to evaluate the response to EOCM were performed in the rabbit ileum. EOCM (1–100 µg·mL-1) reduced the amplitude and area under the curve of spontaneous contractions of the ileum. The contractions induced by carbachol 1 µM, potassium chloride (KCl) 60 mM or Bay K8644 1 µM were reduced by EOCM (30 µg·mL-1). Apamin 1 µM and charybdotoxin 0.01 µM decreased the inhibition induced by EOCM. The d-cAMP 1 µM decreased the inhibition induced by EOCM. l-NNA 10 µM, Rp-8-Br-PET-cGMPS 1 µM, d, l-propargylglycine 2 mM, or aminooxyacetic acid hemihydrochloride 2 mM did not modify the EOCM effect. In conclusion, EOCM induces an antispasmodic effect and could be used in the treatment of intestinal spasms or diarrhea processes. This effect would be mediated by Ca2+, Ca2+-activated K+ channels and cAMP

Zeroing in on more photons and gluons

We discuss radiation zeros that are found in gauge tree amplitudes for processes involving multi-photon emission. Previous results are clarified by examples and by further elaboration. The conditions under which such amplitude zeros occur are identical in form to those for the single-photon zeros, and all radiated photons must travel parallel to each other. Any other neutral particle likewise must be massless (e.g. gluon) and travel in that common direction. The relevance to questions like gluon jet identification and computational checks is considered. We use examples to show how certain multi-photon amplitudes evade the zeros, and to demonstrate the connection to a more general result, the decoupling of an external electromagnetic plane wave in the ``null zone". Brief comments are made about zeros associated with other gauge-boson emission.Comment: 26 page

Assessment of Microplastics Distribution in a Biological Wastewater Treatment

[EN] Full-scale wastewater treatment facilities are not able to prevent microplastics (MPs) from discharging into natural waters and they are also associated with the land application of the sludge. This study evaluates the distribution of microfibers (MFs) in a lab-scale sequencing batch reactor (SBR) fed by synthetic wastewater (SW) for 93 days. The MFs were analyzed through optical microscopy in the mixed liquor (ML) and the effluent, and sulfuric acid digestion was applied to discriminate between natural and synthetic MFs (i.e., MPs). The results of the optical microscopy analyses were further validated through FTIR spectroscopy. A model describing the evolution over time of the MF concentration in the ML was created, accounting for the MFs entering the system through the SW and atmospheric deposition. The ratio between the MF concentration in the ML and the effluent was 1409 ± 781, demonstrating that MFs settle with the sludge. Consistently, in the ML, 64.9% of the recovered MFs were smaller than 1000 µm (average size 968 µm), while in the effluent, 76.1% of MFs were smaller than 1000 µm (average size 772 µm). Overall, 72% of MFs recovered from the ML were natural fibers and sulfuric acid digestion was successful in eliminating the natural MFs.This research was funded by the Spanish Ministry of Science, Innovation and Universities (grant number: RTI2018-096916-B-I00).Castelluccio, S.; Alvim, CB.; Bes-Piá, M.; Mendoza Roca, JA.; Fiore, S. (2022). Assessment of Microplastics Distribution in a Biological Wastewater Treatment. Microplastics. 1(1):141-155. https://doi.org/10.3390/microplastics10100091411551