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46 results on '"D. A. Rocha"'

1. Analysis of water quality at hydrographic basin scale using satellite images, co-occurrence matrices and Bayes classifier

Author

M. G. G. Silva, D. J. Silva, P. D. Costa, R. C. Silva, T. E. B. Cassimiro, L. S. Amorim, D. A. Rocha, and Z. M. A. Peixoto

Subjects
bayes classifier, co-occurrence matrix, satellite image, water quality, Water supply for domestic and industrial purposes, TD201-500, River, lake, and water-supply engineering (General), TC401-506
Abstract

Given the increased risks of water scarcity and the presence of polluting agents in water resources, this paper aims at the development and presentation of a computational tool capable of assessing water quality based on digital processing techniques applied to satellite images. Initially, a database was created for Brazilian regions, consisting of hydrographic basins' satellite images associated with the Water Quality Index (WQI), according to the criteria established by the National Water Agency (ANA). Hitherto, the database consisted of 85 images, 61 were used in the training stage and 24 in the testing stage. In both stages, the images were subjected to thresholding using Otsu's Method, binarization, linear expansion on saturation, application of a Laplacian filter, extraction of characteristics by using co-occurrence matrices and classification by the Bayes Discriminant. Such techniques were also implemented on a computational platform in the MATLAB® environment, responsible for the interface between the system and users. The proposed system presented an approximate 70% success rate regarding the classification of WQIs, which can be improved as more information is made available to improve the databases. HIGHLIGHTS Application of satellite images and processing techniques to assess water quality.; Assessment of water quality in hydrographic basins without on-site measurements.; Application of Otsu's method, linear expansion by saturation and Laplacian filter.; Water features extraction and classification by co-occurrence matrices and Bayesian Linear Discriminant Analysis Classifier.;

Published
2021
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2. 3D{\pi}: Three-Dimensional Positron Imaging, A Novel Total-Body PET Scanner Using Xenon-Doped Liquid Argon Scintillator

Author

Zabihi, Azam, Li, Xinran, Ramirez, Alejandro, Rolo, Manuel D. Da Rocha, Franco, Davide, Gabriele, Federico, Galbiati, Cristiano, Lai, Michela, Marlow, Daniel R., Renshaw, Andrew, Westerdale, Shawn, and Wada, Masayuki

Subjects
Physics - Medical Physics
Abstract

Objective: This paper introduces a novel PET imaging methodology called 3-dimensional positron imaging (3D{\pi}), which integrates total-body (TB) coverage, time-of-flight (TOF) technology, ultra-low dose imaging capabilities, and ultra-fast readout electronics inspired by emerging technology from the DarkSide collaboration. Approach: The study evaluates the performance of 3D{\pi} using Monte Carlo simulations based on NEMA NU 2-2018 protocols. The methodology employs a homogenous, monolithic scintillator composed of liquid argon (LAr) doped with xenon (Xe) with silicon photomultipliers (SiPM) operating at cryogenic temperatures. Main results: Significant enhancements in system performance are observed, with the 3D{\pi} system achieving a noise equivalent count rate (NECR) of 3.2 Mcps which is approximately two times higher than uEXPLORER's peak NECR (1.5 Mcps) at 17.3 (kBq/mL). Spatial resolution measurements show an average FWHM of 2.7 mm across both axial positions. The system exhibits superior sensitivity, with values reaching 373 kcps/MBq with a line source at the center of the field of view. Additionally, 3D{\pi} achieves a TOF resolution of 151 ps at 5.3 kBq/mL, highlighting its potential to produce high-quality images with reduced noise levels. Significance: The study underscores the potential of 3D{\pi} in improving PET imaging performance, offering the potential for shorter scan times and reduced radiation exposure for patients. The Xe-doped LAr offers advantages such as fast scintillation, enhanced light yield, and cost-effectiveness. Future research will focus on optimizing system geometry and further refining reconstruction algorithms to exploit the strengths of 3D{\pi} for clinical applications., Comment: 8 pages, 8 figures, 6 tables

Published
2024

3. Benchmarking the design of the cryogenics system for the underground argon in DarkSide-20k

Author

Collaboration, DarkSide-20k, Acerbi, F., Adhikari, P., Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Amaudruz, P., Angiolilli, M., Aprile, E., Ardito, R., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. C., Azzolini, O., Back, H. O., Balmforth, Z., Olmedo, A. Barrado, Barrillon, P., Batignani, G., Bhowmick, P., Blua, S., Bocci, V., Bonivento, W., Bottino, B., Boulay, M. G., Buchowicz, A., Bussino, S., Busto, J., Cadeddu, M., Cadoni, M., Calabrese, R., Camillo, V., Caminata, A., Canci, N., Capra, A., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castellani, A., Castello, P., Cavalcante, P., Cebrian, S., Ruiz, J. Cela, Chashin, S., Chepurnov, A., Cifarelli, L., Cintas, D., Citterio, M., Cleveland, B., Coadou, Y., Cocco, V., Colaiuda, D., Vilda, E. Conde, Consiglio, L., Costa, B. S., Czubak, M., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Darbo, G., Davini, S., De Cecco, S., De Guido, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Ludovico, A., Di Noto, L., Di Stefano, P., Dias, L. K., Mairena, D. Díaz, Ding, X., Dionisi, C., Dolganov, G., Dordei, F., Dronik, V., Elersich, A., Ellingwood, E., Erjavec, T., Diaz, M. Fernandez, Ficorella, A., Fiorillo, G., Franchini, P., Franco, D., Gatti, H. Frandini, Frolov, E., Gabriele, F., Gahan, D., Galbiati, C., Galiński, G., Gallina, G., Gallus, G., Garbini, M., Abia, P. Garcia, Gawdzik, A., Gendotti, A., Ghisi, A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Grandi, L., Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Hamer, A., Haranczyk, M., Harrop, B., Hessel, T., Hill, S., Horikawa, S., Hu, J., Hubaut, F., Hucker, J., Hugues, T., Hungerford, E. V., Ianni, A., Ippolito, V., Jamil, A., Jillings, C., Jois, S., Kachru, P., Keloth, R., Kemmerich, N., Kemp, A., Kendziora, C. L., Kimura, M., Kish, A., Kondo, K., Korga, G., Kotsiopoulou, L., Koulosousas, S., Kubankin, A., Kunzé, P., Kuss, M., Kuźniak, M., Kuzwa, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Leoni, A., Lidey, L., Lissia, M., Luzzi, L., Lychagina, O., Macfadyen, O., Machulin, I. N., Manecki, S., Manthos, I., Mapelli, L., Marasciulli, A., Mari, S. M., Mariani, C., Maricic, J., Martinez, M., Martoff, C. J., Matteucci, G., Mavrokoridis, K., McDonald, A. B., Mclaughlin, J., Merzi, S., Messina, A., Milincic, R., Minutoli, S., Mitra, A., Moharana, A., Moioli, S., Monroe, J., Moretti, E., Morrocchi, M., Mroz, T., Muratova, V. N., Murphy, M., Murra, M., Muscas, C., Musico, P., Nania, R., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikoloudaki, E., Nowak, J., Olchanski, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Papi, D., Pastuszak, G., Paternoster, G., Peck, A., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Perez, R., Perotti, F., Pesudo, V., Piacentini, S. I., Pino, N., Plante, G., Pocar, A., Poehlmann, M., Pordes, S., Pralavorio, P., Price, D., Puglia, S., Bazetto, M. Queiroga, Ragusa, F., Ramachers, Y., Ramirez, A., Ravinthiran, S., Razeti, M., Renshaw, A. L., Rescigno, M., Retiere, F., Rignanese, L. P., Rivetti, A., Roberts, A., Roberts, C., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Rudik, D., Sabia, M., Salomone, P., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Santos, E. M., Savarese, C., Scapparone, E., Schillaci, G., Schuckman II, F. G., Scioli, G., Semenov, D. A., Shalamova, V., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smirnova, T., Smith, B., Sotnikov, A., Spadoni, F., Spangenberg, M., Stefanizzi, R., Steri, A., Stornelli, V., Stracka, S., Sulis, S., Sung, A., Sunny, C., Suvorov, Y., Szelc, A. M., Taborda, O., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thompson, A., Thorpe, T. N., Tonazzo, A., Torres-Lara, S., Tricomi, A., Unzhakov, E. V., Vallivilayil, T. J., Van Uffelen, M., Velazquez-Fernandez, L., Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Vyas, B., Wada, M., Walczak, M. B., Wang, H., Wang, Y., Westerdale, S., Williams, L., Wojaczyński, R., Wojcik, M., Wojcik, M. M., Wright, T., Xiao, X., Xie, Y., Yang, C., Yin, J., Zabihi, A., Zakhary, P., Zani, A., Zhang, Y., Zhu, T., Zichichi, A., Zuzel, G., and Zykova, M. P.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

DarkSide-20k (DS-20k) is a dark matter detection experiment under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It utilises ~100 t of low radioactivity argon from an underground source (UAr) in its inner detector, with half serving as target in a dual-phase time projection chamber (TPC). The UAr cryogenics system must maintain stable thermodynamic conditions throughout the experiment's lifetime of >10 years. Continuous removal of impurities and radon from the UAr is essential for maximising signal yield and mitigating background. We are developing an efficient and powerful cryogenics system with a gas purification loop with a target circulation rate of 1000 slpm. Central to its design is a condenser operated with liquid nitrogen which is paired with a gas heat exchanger cascade, delivering a combined cooling power of >8 kW. Here we present the design choices in view of the DS-20k requirements, in particular the condenser's working principle and the cooling control, and we show test results obtained with a dedicated benchmarking platform at CERN and LNGS. We find that the thermal efficiency of the recirculation loop, defined in terms of nitrogen consumption per argon flow rate, is 95 % and the pressure in the test cryostat can be maintained within $\pm$(0.1-0.2) mbar. We further detail a 5-day cool-down procedure of the test cryostat, maintaining a cooling rate typically within -2 K/h, as required for the DS-20k inner detector. Additionally, we assess the circuit's flow resistance, and the heat transfer capabilities of two heat exchanger geometries for argon phase change, used to provide gas for recirculation. We conclude by discussing how our findings influence the finalisation of the system design, including necessary modifications to meet requirements and ongoing testing activities., Comment: 45 pages, 24 figures

Published
2024

4. DarkSide-20k sensitivity to light dark matter particles

Author

Collaboration, DarkSide-20k, Acerbi, F., Adhikari, P., Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Amaudruz, P., Angiolilli, M., Aprile, E., Ardito, R., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. C., Azzolini, O., Back, H. O., Balmforth, Z., Olmedo, A. Barrado, Barrillon, P., Batignani, G., Bhowmick, P., Blua, S., Bocci, V., Bonivento, W., Bottino, B., Boulay, M. G., Buchowicz, A., Bussino, S., Busto, J., Cadeddu, M., Cadoni, M., Calabrese, R., Camillo, V., Caminata, A., Canci, N., Capra, A., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castellani, A., Castello, P., Cavalcante, P., Cebrian, S., Ruiz, J. M. Cela, Chashin, S., Chepurnov, A., Cifarelli, L., Cintas, D., Citterio, M., Cleveland, B., Coadou, Y., Cocco, V., Colaiuda, D., Vilda, E. Conde, Consiglio, L., Costa, B. S., Czubak, M., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Darbo, G., Davini, S., De Cecco, S., De Guido, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Ludovico, A., Di Noto, L., Di Stefano, P., Dias, L. K., Mairena, D. Díaz, Ding, X., Dionisi, C., Dolganov, G., Dordei, F., Dronik, V., Elersich, A., Ellingwood, E., Erjavec, T., Diaz, M. Fernandez, Ficorella, A., Fiorillo, G., Franchini, P., Franco, D., Gatti, H. Frandini, Frolov, E., Gabriele, F., Gahan, D., Galbiati, C., Galiński, G., Gallina, G., Gallus, G., Garbini, M., Abia, P. Garcia, Gawdzik, A., Gendotti, A., Ghisi, A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Grandi, L., Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Hamer, A., Haranczyk, M., Harrop, B., Hessel, T., Hill, S., Horikawa, S., Hu, J., Hubaut, F., Hucker, J., Hugues, T., Hungerford, E. V., Ianni, A., Ippolito, V., Jamil, A., Jillings, C., Jois, S., Kachru, P., Keloth, R., Kemmerich, N., Kemp, A., Kendziora, C. L., Kimura, M., Kondo, K., Korga, G., Kotsiopoulou, L., Koulosousas, S., Kubankin, A., Kunzé, P., Kuss, M., Kuźniak, M., Kuzwa, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Leoni, A., Lidey, L., Lissia, M., Luzzi, L., Lychagina, O., Macfadyen, O., Machulin, I. N., Manecki, S., Manthos, I., Mapelli, L., Marasciulli, A., Mari, S. M., Mariani, C., Maricic, J., Martinez, M., Martoff, C. J., Matteucci, G., Mavrokoridis, K., McDonald, A. B., Mclaughlin, J., Merzi, S., Messina, A., Milincic, R., Minutoli, S., Mitra, A., Moioli, S., Monroe, J., Moretti, E., Morrocchi, M., Mroz, T., Muratova, V. N., Murphy, M., Murra, M., Muscas, C., Musico, P., Nania, R., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikoloudaki, E., Nowak, J., Olchanski, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Papi, D., Pastuszak, G., Paternoster, G., Peck, A., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Perez, R., Perotti, F., Pesudo, V., Piacentini, S. I., Pino, N., Plante, G., Pocar, A., Poehlmann, M., Pordes, S., Pralavorio, P., Price, D., Puglia, S., Bazetto, M. Queiroga, Ragusa, F., Ramachers, Y., Ramirez, A., Ravinthiran, S., Razeti, M., Renshaw, A. L., Rescigno, M., Retiere, F., Rignanese, L. P., Rivetti, A., Roberts, A., Roberts, C., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Rudik, D., Sabia, M., Salomone, P., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Santos, E. M., Savarese, C., Scapparone, E., Schillaci, G., Schuckman II, F. G., Scioli, G., Semenov, D. A., Shalamova, V., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smirnova, T., Smith, B., Sotnikov, A., Spadoni, F., Spangenberg, M., Stefanizzi, R., Steri, A., Stornelli, V., Stracka, S., Sulis, S., Sung, A., Sunny, C., Suvorov, Y., Szelc, A. M., Taborda, O., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thompson, A., Tonazzo, A., Torres-Lara, S., Tricomi, A., Unzhakov, E. V., Vallivilayil, T. J., Van Uffelen, M., Velazquez-Fernandez, L., Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Vyas, B., Walczak, M. B., Wang, Y., Wang, H., Westerdale, S., Williams, L., Wojaczyński, R., Wojcik, M., Wojcik, M. M., Wright, T., Xie, Y., Yang, C., Yin, J., Zabihi, A., Zakhary, P., Zani, A., Zhang, Y., Zhu, T., Zichichi, A., Zuzel, G., and Zykova, M. P.

Subjects
High Energy Physics - Experiment, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The dual-phase liquid argon time projection chamber is presently one of the leading technologies to search for dark matter particles with masses below 10 GeV/c$^2$. This was demonstrated by the DarkSide-50 experiment with approximately 50 kg of low-radioactivity liquid argon as target material. The next generation experiment DarkSide-20k, currently under construction, will use 1,000 times more argon and is expected to start operation in 2027. Based on the DarkSide-50 experience, here we assess the DarkSide-20k sensitivity to models predicting light dark matter particles, including Weakly Interacting Massive Particles (WIMPs) and sub-GeV/c$^2$ particles interacting with electrons in argon atoms. With one year of data, a sensitivity improvement to dark matter interaction cross-sections by at least one order of magnitude with respect to DarkSide-50 is expected for all these models. A sensitivity to WIMP--nucleon interaction cross-sections below $1\times10^{-42}$ cm$^2$ is achievable for WIMP masses above 800 MeV/c$^2$. With 10 years exposure, the neutrino fog can be reached for WIMP masses around 5 GeV/c$^2$., Comment: submitted to Nature Communications

Published
2024

5. A new hybrid gadolinium nanoparticles-loaded polymeric material for neutron detection in rare event searches

Author

Collaboration, DarkSide-20k, Acerbi, F., Adhikari, P., Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F., Alexander, T., Alton, A. K., Amaudruz, P., Angiolilli, M., Aprile, E., Ardito, R., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. C., Azzolini, O., Back, H. O., Balmforth, Z., Olmedo, A. Barrado, Barrillon, P., Batignani, G., Bhowmick, P., Bocci, V., Bonivento, W., Bottino, B., Boulay, M. G., Buchowicz, A., Bussino, S., Busto, J., Cadeddu, M., Cadoni, M., Calabrese, R., Camillo, V., Caminata, A., Canci, N., Capra, A., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castellani, A., Castello, P., Cavalcante, P., Cavallo, D., Cebrian, S., Ruiz, J. Cela, Chashin, S., Chepurnov, A., Cifarelli, L., Cintas, D., Citterio, M., Cleveland, B., Coadou, Y., Cocco, V., Colaiuda, D., Vilda, E. Conde, Consiglio, L., Costa, B. S., Czubak, M., D'Auria, S., Rolo, M. D. Da Rocha, Darbo, G., Davini, S., De Cecco, S., De Guido, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Ludovico, A., Di Noto, L., Di Stefano, P., Dias, L. K., Mairena, D. Díaz, Ding, X., Dionisi, C., Dolganov, G., Dordei, F., Dronik, V., Elersich, A., Ellingwood, E., Erjavec, T., Diaz, M. Fernandez, Ficorella, A., Fiorillo, G., Franchini, P., Franco, D., Gatti, H. Frandini, Frolov, E., Gabriele, F., Gahan, D., Galbiati, C., Galinski, G., Gallina, G., Garbini, M., Abia, P. Garcia, Gawdzik, A., Gendotti, A., Ghisi, A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Grandi, L., Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Hamer, A., Haranczyk, M., Harrop, B., Hessel, T., Hill, S., Horikawa, S., Hu, J., Hubaut, F., Hucker, J., Hugues, T., Hungerford, E. V., Ianni, A., Ippolito, V., Jamil, A., Jillings, C., Keloth, R., Kemmerich, N., Kemp, A., Kendziora, C. L., Kimura, M., Kondo, K., Korga, G., Kotsiopoulou, L., Koulosousas, S., Kubankin, A., Kuss, M., Kuzniak, M., Kuzwa, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Leoni, A., Lidey, L., Lissia, M., Luzzi, L., Lychagina, O., Macfadyen, O., Machulin, I. N., Manecki, S., Manthos, I., Mapelli, L., Marasciulli, A., Mari, S. M., Mariani, C., Maricic, J., Marini, A., Martinez, M., Martoff, C. J., Matteucci, G., Mavrokoridis, K., McDonald, A. B., Mclaughlin, J., Merzi, S., Messina, A., Milincic, R., Minutoli, S., Mitra, A., Moharana, A., Moioli, S., Monroe, J., Moretti, E., Morrocchi, M., Mroz, T., Muratova, V. N., Murphy, M., Murra, M., Muscas, C., Musico, P., Nania, R., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikoloudaki, E., Nowak, J., Olchanski, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Papi, D., Pastuszak, G., Paternoster, G., Peddis, D., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Perez, R., Perotti, F., Pesudo, V., Piacentini, S. I., Pino, N., Plante, G., Pocar, A., Poehlmann, M., Pordes, S., Pralavorio, P., Price, D., Puglia, S., Bazetto, M. Queiroga, Ragusa, F., Ramachers, Y., Ramirez, A., Ravinthiran, S., Razeti, M., Renshaw, A. L., Rescigno, M., Retiere, F., Rignanese, L. P., Rivetti, A., Roberts, A., Roberts, C., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Rudik, D., Sabia, M., Sadashivajois, S., Salomone, P., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Santos, E. M., Savarese, C., Scapparone, E., Schillaci, G., Schuckman II, F. G., Scioli, G., Semenov, D. A., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Slimani, S., Smirnov, O., Smirnova, T., Smith, B., Sotnikov, A., Spadoni, F., Spangenberg, M., Stefanizzi, R., Steri, A., Stornelli, V., Stracka, S., Sulis, S., Sung, A., Sunny, C., Suvorov, Y., Szelc, A. M., Taborda, O., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thompson, A., Tonazzo, A., Torres-Lara, S., Tosi, S., Tricomi, A., Unzhakov, E. V., Vallivilayil, T. J., Van Uffelen, M., Velazquez-Fernandez, L., Viant, T., Vicini, S., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Vyas, B., Wada, M., Walczak, M. B., Wang, H., Wang, Y., Westerdale, S., Williams, L., Wojaczynski, R., Wojcik, M. M., Wojcik, M., Wright, T., Xie, Y., Yang, C., Yin, J., Zabihi, A., Zakhary, P., Zani, A., Zhang, Y., Zhu, T., Zichichi, A., Zuzel, G., and Zykova, M. P.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Experiments aimed at direct searches for WIMP dark matter require highly effective reduction of backgrounds and control of any residual radioactive contamination. In particular, neutrons interacting with atomic nuclei represent an important class of backgrounds due to the expected similarity of a WIMP-nucleon interaction, so that such experiments often feature a dedicated neutron detector surrounding the active target volume. In the context of the development of DarkSide-20k detector at INFN Gran Sasso National Laboratory (LNGS), several R&D projects were conceived and developed for the creation of a new hybrid material rich in both hydrogen and gadolinium nuclei to be employed as an essential element of the neutron detector. Thanks to its very high cross-section for neutron capture, gadolinium is one of the most widely used elements in neutron detectors, while the hydrogen-rich material is instrumental in efficiently moderating the neutrons. In this paper results from one of the R&Ds are presented. In this effort the new hybrid material was obtained as a poly(methyl methacrylate) (PMMA) matrix, loaded with gadolinium oxide in the form of nanoparticles. We describe its realization, including all phases of design, purification, construction, characterization, and determination of mechanical properties of the new material.

Published
2024
Full Text
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6. MIL-101(Fe)@ceramic-monolith for arsenic removal in aqueous solutions

Author

D. Villarroel-Rocha, C. García-Carvajal, S. Amaya-Roncancio, J. Villarroel-Rocha, D. A. Torres-Ceron, E. Restrepo-Parra, and K. Sapag

Subjects
Medicine, Science
Abstract

Abstract In this work, we present the preparation of a hybrid material constituted by a Metal-Organic Framework (type MIL-101(Fe)) and a natural clay ceramic monolith (NCCM), the materials were successfully assembled through an in-situ hydrothermal method. The composites were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), N2 adsorption-desorption isotherms at 77 K and CO2 adsorption at 273 K; these techniques confirmed the obtaining of the hybrid material and, in addition, through studies before and after adsorption mechanisms involved were identified. Then, the As(V) adsorption capacity of the materials was evaluated using an aqueous arsenic solution; from which high adsorption capacities of up to 268 mg g− 1 and 61.5 mg g− 1, respectively. In addition, kinetic and equilibrium studies of As(V) adsorption were carried out. Finally, the potential capacities of the hybrid material consisting of Al2O3, AlO6-SiO4 and Fe3O4 for the adsorption of H3AsO4, were studied through density functional theory calculations.

Published
2024
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7. Assessment of Urban Heat Islands in an Eastern Amazonian city

Author

L. L. Raiol, Y. A. D. S. Rocha, D. C. R. Santos, A. M. M. de Lima, and A. Velastegui-Montoya

Subjects
Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820
Abstract

The increase in heat islands in large cities, especially in tropical areas, has been a significant problem, as the rise in temperature can cause health issues for people. Therefore, this research aimed to analyze changes in land surface temperature (LST) and urban heat islands (UHI) in 1986 and 2023. The methodological procedures were carried out in four steps: I) Calculation of LST and UHI using the Landsat collection; II) Zonal statistics of the mean, the median, the minimum, maximum, and standard deviation of LST and UHI in each neighbourhood; III) Kruskal-Wallis Test applied to the average LST between 1986 and 2023; and IV) Assessment of the spatial autocorrelation of neighbourhoods using Bivariate Global and Local Moran’s I Index between LST and UHI. The results showed that in 2023, there was an increase in heat islands in central city neighbourhoods compared to 1986, as demonstrated by the Kruskal-Wallis test, which showed significant differences in LST. The global Moran’s I Index presented a value of 0.642, indicating a robust spatial autocorrelation in local studies. The neighbourhoods that showed high correlations were Campina, Cidade Velha, Cremação, Condor, Fátima, Jurunas, Nazaré, Pedreira, Reduto, São Braz, and Umarizal. The neighbourhoods that showed low correlations were Águas Lindas, Aurá, Curió-Utinga, Guanabara, and Parque Guajará. These results are directly linked to the intensification of urbanization and low vegetation cover, especially in central areas of the city, which showed a high correlation. These findings can aid decision-makers and support urban planning, focusing on neighbourhoods with higher average temperatures.

Published
2024
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8. Directionality of nuclear recoils in a liquid argon time projection chamber

Author

Collaboration, The DarkSide-20k, Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Amaudruz, P., Corona, M. Atzori, Ave, M., Avetisov, I. Ch., Azzolini, O., Back, H. O., Balmforth, Z., Barrado-Olmedo, A., Barrillon, P., Basco, A., Batignani, G., Bocci, V., Bonivento, W. M., Bottino, B., Boulay, M. G., Busto, J., Cadeddu, M., Caminata, A., Canci, N., Cappello, G., Capra, A., Caprioli, S., Caravati, M., Cargioli, N., Carlini, M., Castello, P., Cataudella, V., Cavalcante, P., Cavuoti, S., Cebrian, S., Ruiz, J. M. Cela, Chashin, S., Chepurnov, A., Chyhyrynets, E., Cifarelli, L., Cintas, D., Citterio, M., Cleveland, B., Cocco, V., Vilda, E. Conde, Consiglio, L., Copello, S., Covone, G., Czubak, M., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Davini, S., de Candia, A., De Cecco, S., De Gruttola, D., De Filippis, G., Dell'Aquila, D., De Pasquale, S., De Rosa, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Noto, L., Dionisi, C., Di Stefano, P., Dolganov, G., Dordei, F., Elersich, A., Ellingwood, E., Erjavec, T., Diaz, M. Fernandez, Fiorillo, G., Franchini, P., Franco, D., Funicello, N., Gabriele, F., Gahan, D., Galbiati, C., Gallina, G., Gallus, G., Garbini, M., Abia, P. Garcia, Gendotti, A., Ghiano, C., Giganti, C., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guan, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A. L., Hamer, A., Haranczyk, M., Hessel, T., Hill, S., Horikawa, S., Hubaut, F., Hucker, J., Hugues, T., Ianni, An., Ippolito, V., Jillings, C., Jois, S., Kachru, P., Kemmerich, N., Kemp, A. A., Kendziora, C. L., Kimura, M., Kochanek, I., Kondo, K., Korga, G., Koulosousas, S., Kubankin, A., Kuss, M., Kuzniak, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Leoni, A., Li, X., Lidey, L., Lissia, M., Luzzi, L., Lychagina, O., Macfadyen, O., Machulin, I. N., Manecki, S., Manthos, I., Mapelli, L., Margotti, A., Marik, S. M., Mariani, C., Maricic, J., Marini, A., Martínez, M., Martoff, C. J., Matteucci, G., Mavrokoridis, K., McDonald, A. B., Messina, A., Milincic, R., Mitra, A., Moharana, A., Monroe, J., Moretti, E., Morrocchi, M., Mróz, T., Muratova, V. N., Muscas, C., Musico, P., Nania, R., Nessi, M., Nieradka, G., Nikolopoulos, K., Nowak, J., Olchansky, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pagani, L., Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pegoraro, P. A., Pelczar, K., Pesudo, V., Piacentini, S., Pino, N., Pocar, A., Poehlmann, D. M., Pordes, S., Pralavorio, P., Price, D., Ragusa, F., Ramachers, Y., Razeti, M., Renshaw, A. L., Rescigno, M., Retiere, F., Rignanese, L. P., Ripoli, C., Rivetti, A., Roberts, A., Roberts, C., Rode, J., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Sabia, M. A., Salomone, P., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Savarese, C., Scapparone, E., Schillaci, G., Schuckman II, F. G., Scioli, G., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smirnova, T., Smith, B., Sosa, A., Spadoni, F., Spangenberg, M., Stefanizzi, R., Steri, A., Stornelli, V., Stracka, S., Stringer, M., Sulis, S., Sung, A., Suvorov, Y., Szelc, A. M., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thorpe, T. N., Tonazzo, A., Tricomi, A., Unzhakov, E. V., John, T. Vallivilayil, Van Uffelen, M., Viant, T., Viel, S., Vogelaar, R. B., Vossebeld, J., Wada, M., Walczak, M. B., Wang, H., Wang, Y., Westerdale, S., Williams, L., Wingerter-Seez, I., Wojaczynski, R., Wojcik, Ma. M., Wright, T., Xie, Y., Yang, C., Zabihi, A., Zakhary, P., Zani, A., Zichichi, A., Zuzel, G., and Zykova, M. P.

Subjects
Physics - Instrumentation and Detectors
Abstract

The direct search for dark matter in the form of weakly interacting massive particles (WIMP) is performed by detecting nuclear recoils (NR) produced in a target material from the WIMP elastic scattering. A promising experimental strategy for direct dark matter search employs argon dual-phase time projection chambers (TPC). One of the advantages of the TPC is the capability to detect both the scintillation and charge signals produced by NRs. Furthermore, the existence of a drift electric field in the TPC breaks the rotational symmetry: the angle between the drift field and the momentum of the recoiling nucleus can potentially affect the charge recombination probability in liquid argon and then the relative balance between the two signal channels. This fact could make the detector sensitive to the directionality of the WIMP-induced signal, enabling unmistakable annual and daily modulation signatures for future searches aiming for discovery. The Recoil Directionality (ReD) experiment was designed to probe for such directional sensitivity. The TPC of ReD was irradiated with neutrons at the INFN Laboratori Nazionali del Sud, and data were taken with 72 keV NRs of known recoil directions. The direction-dependent liquid argon charge recombination model by Cataudella et al. was adopted and a likelihood statistical analysis was performed, which gave no indications of significant dependence of the detector response to the recoil direction. The aspect ratio R of the initial ionization cloud is estimated to be 1.037 +/- 0.027 and the upper limit is R < 1.072 with 90% confidence level, Comment: 20 pages, 10 figures, submitted to Eur. Phys. J. C

Published
2023

9. Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel

Author

Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Amaudruz, P., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. Ch., Avetisov, R. I., Azzolini, O., Back, H. O., Balmforth, Z., Barbarian, V., Olmedo, A. Barrado, Barrillon, P., Basco, A., Batignani, G., Berzin, E., Bondar, A., Bonivento, W. M., Borisova, E., Bottino, B., Boulay, M. G., Buccino, G., Bussino, S., Busto, J., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canci, N., Capra, A., Caprioli, S., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castello, P., Cataudella, V., Cavalcante, P., Cavuoti, S., Cebrian, S., Ruiz, J. M. Cela, Chashin, S., Chepurnov, A., Chyhyrynets, E, Cicalò, C., Cifarelli, L., Cintas, D., Cocco, V., Vilda, E. Conde, Consiglio, L., Copello, S., Covone, G., Cross, S., Czudak, P., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Dadoun, O., Daniel, M., Davini, S., De Candia, A., De Cecco, S., De Falco, A., De Filippis, G., De Gruttola, D., De Pasquale, S., De Rosa, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Noto, L., Di Stefano, P., Dionisi, C., Dolganov, G., Dordei, F., Doria, L., Erjavec, T., Diaz, M. Fernandez, Fiorillo, G., Franceschi, A., Franchini, P., Franco, D., Frolov, E., Funicello, N., Gabriele, F., Gahan, D., Galbiati, C., Gallina, G., Gallus, G., Garbini, M., Abia, P. Garcia, Gendotti, A., Ghiano, C., Giampaolo, R. A., Giganti, C., Giorgi, M. A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Gorman, D., Diaz, R. Graciani, Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guan, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hall, J. B., Hallin, A. L., Hamer, A., Helton, H., Haranczyk, M., Hessel, T., Hill, S., Horikawa, S., Hubaut, F., Hugues, T., Hungerford, E. V., Ianni, An., Ippolito, V., Jillings, C., Kachru, P., Kemp, A. A., Kendziora, C. L., Keppel, G., Khomyakov, A. V., Kimura, M., Kochanek, I., Kondo, K., Korga, G., Koulosousas, S., Kubankin, A., Kuss, M., Kuźniak, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Li, X., Lidey, L., Lipp, J., Lissia, M., Longo, G., Luzzi, L., Macfadyen, O., Machulin, I. N., Manthos, I., Mapelli, L., Margotti, A., Mari, S. M., Mariani, C., Maricic, J., Marini, A., Martínez, M., Martoff, C. J., Masoni, A., Mavrokoridis, K., Mazzi, A., McDonald, A. B., Messina, A., Milincic, R., Moggi, A., Moharana, A., Monroe, J., Morrocchi, M., Mozhevitina, E. N., Mróz, T., Muratova, V. N., Muscas, C., Musico, P., Nania, R., Napolitano, T., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikulin, I., Nowak, J., Olchansky, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pagani, L., Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pegoraro, P. A., Pelczar, K., Pellegrino, C., Perotti, F., Pesudo, V., Piacentini, S., Pietropaolo, F., Pino, N., Pira, C., Pocar, A., Poehlmann, D. M., Pordes, S., Pralavorio, P., Price, D., Raffaelli, F., Ragusa, F., Ramachers, Y., Ramirez, A., Razeti, M., Razeto, A., Renshaw, A. L., Rescigno, M., Resnati, F., Retiere, F., Rignanese, L. P., Ripoli, C., Rivetti, A., Roberts, A., Roberts, C., Rode, J., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Sadashivajois, S., Saffold, T. R., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Savarese, C., Scapparone, E., Scioli, G., Semenov, D. A., Shchagin, A., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smirnova, T., Smith, B., Sokolov, A., Spangenberg, M., Stefanizzi, R., Steri, A., Stracka, S., Strickland, V., Stringer, M., Sulis, S., Sung, A., Suvorov, Y., Szelc, A. M., Türkoğ, C., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thorpe, T. N., Tonazzo, A., Torres-Lara, S., Tricomi, A., Unzhakov, E. V., John, T. Vallivilayil, Van Uffelen, M., Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Wada, M., Walczak, M. B., Wang, Y., Westerdale, S., Wheadon, R. J., Williams, L., Wingerter-Seez, I., Wojaczyński, R., Wojcik, Ma. M., Wojcik, Ma., Wright, T., Xie, Y., Yang, C., Zabihi, A., Zakhary, P., Zani, A., Zichichi, A., Zuzel, G., and Zykova, M. P.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Dark matter lighter than 10 GeV/c$^2$ encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement. Sensitivity to light dark matter is explored for various potential energy thresholds and background rates. These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino floor for GeV-scale masses and significant sensitivity down to 10 MeV/c$^2$ considering the Migdal effect or interactions with electrons. Requirements for optimizing the detector's sensitivity are explored, as are potential sensitivity gains from modeling and mitigating spurious electron backgrounds that may dominate the signal at the lowest energies.

Published
2022
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10. Insecticide paints: a new community strategy for controlling dengue and zika mosquito vectors in Cabo Verde

Author

Lara Ferrero Gómez, Hélio D. Ribeiro Rocha, Ignacio Gil Torró, Irene Serafín Pérez, Deinilson Conselheiro Mendes, Keily L. Fonseca Silva, Davidson D. Sousa Rocha Monteiro, Jailson P. Tavares Dos Reis, Silvânia Veiga Leal, Luis F. Vitória Soulé, Jailton C. Fortes, Maria da Luz Lima Mendonça, Eva Caballero Mendez, and Basilio Valladares Hernández

Subjects
dengue, zika, insecticide paint, vector control, community, TINTAEDES project, Arctic medicine. Tropical medicine, RC955-962
Abstract

BackgroundCabo Verde, an island country in West Africa, has been affected since human colonization by epidemics of vector-borne diseases with major epidemics of dengue and zika in recent years. Although there is a national program for integrated vector control, innovative strategies that reinforce routine activities and strengthen vector control are necessary to prevent the emergence or reemergence of arboviruses and new epidemics of dengue and zika. Insecticide paints are evidenced as new technologies for the formulation of insecticides in a more residual and safe way. The TINTAEDES project aimed to assess the efficacy, acceptability, and operational deployment of an insecticide paint for Aedes control.Methodology/Principal findingsLaboratory and small-scale field trials were conducted, assessing mortality through World Health Organization cone bioassays. A community-based intervention study in the neighborhoods of Várzea and Tira Chapéu in the city of Praia, Cabo Verde, was developed. The intervention is a paint self-application model by homeowners and neighborhood volunteers. The intervention was evaluated based on entomological indicators and the responses given by the residents of the painted houses to a questionnaire on the knowledge, satisfaction, and safety of insecticidal paints. A transfluthrin-based insecticide paint was effective against wild Ae. aegypti for one year in the laboratory and semi-field conditions. Residents largely perceived a reduction in mosquito presence in the treated houses (98%).ConclusionInsecticide paints are presented as an effective innovation strategy for mosquito control, which could be implemented as a reinforcement of the measures carried out by the vector control program in the city of Praia and throughout the country.

Published
2024
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11. O IMPACTO DA EXPOSIÇÃO AO BISFENOL A NA INFERTILIDADE MASCULINA DE HUMANOS: UMA ATUALIZAÇÃO DOS ÚLTIMOS 5 ANOS

Author

LAFAYETTE SILVA, ITALO, primary, LUIZA D`ALESSANDRO ROCHA, BÁRBARA, additional, COSTA LARA, FERNANDA, additional, DE LIMA MINARI, FERNANDO, additional, FERRI ALMEIDA, GABRIELA, additional, LUCIANE MARTINS, GABRIELA, additional, DE MELO COSTA, GIOVANNA, additional, AMARAL FREITAS, SAMARA, additional, MATEUS COSTA LARA, VICTOR, additional, DE CAMPOS PINHEIRO, MÔNICA, additional, and RANUCCI LUCHIARI, HELOISE, additional

Published
2023
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13. Untangling biodiversity interactions: A meta network on pollination in Earth's most diverse tropical savanna

Author

Ludmilla M. S. Aguiar, Ugo M. Diniz, Igor D. Bueno‐Rocha, Laura R. A. Filomeno, Luísa S. Aguiar‐Machado, Priscilla A. Gomes, and Pedro H. B. Togni

Subjects
Brazilian Cerrado, conservation hotspot, floral visitors, modularity, mutualistic network, trait matching, Ecology, QH540-549.5
Abstract

Abstract Pollination is vital for ecosystem functioning, especially in biodiversity‐rich regions like the Brazilian Cerrado. Our research establishes a comprehensive meta network of pollinator–plant interactions within this biome. We quantified the importance of different pollinator groups, identifying keystone species. We examined potential biases in sampling effort and the spatial behavior of interactions within the heterogeneous Cerrado plant physiognomies. Our investigation uncovered 1499 interactions among 293 plant species and 386 visitor species, with legitimate pollination accounting for 42.4% of the interactions. The network exhibited modularity, driven by bees and insects, with vertebrates bridging diurnal and nocturnal modules. While a generalized pattern emerged, high specialization existed within modules due to habitat diversity. Bees, particularly Apis mellifera (exotic) and Trigona spinipes (native), played central roles as network hubs. Hummingbirds and bats, engaged in specialized interactions showing strong connectivity within and between modules. Interestingly, invertebrate–vertebrate modules were more prevalent than expected in the meta network. However, a bias was evident, primarily within specific biogeographical districts with fragmented landscapes and intrusion from other biomes. Variations in plant species and endemism rates influenced pollinator occurrence and the Cerrado network topology. Our study offers valuable insights into pollinator–plant interactions within the Cerrado, encompassing both invertebrates and vertebrates. The modeled network represents a significant step in understanding the structural complexity of pollination networks, integrating partial networks from diverse pollination systems within heterogeneous habitats. Nevertheless, a biogeographical bias could limit a comprehensive understanding of network functionality across the Cerrado.

Published
2024
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14. Measurement of isotopic separation of argon with the prototype of the cryogenic distillation plant Aria for dark matter searches

Author

E. Aaron, P. Agnes, I. Ahmad, S. Albergo, I. F. M. Albuquerque, T. Alexander, A. K. Alton, P. Amaudruz, M. Atzori Corona, M. Ave, I. Ch. Avetisov, O. Azzolini, H. O. Back, Z. Balmforth, A. Barrado, P. Barrillon, A. Basco, G. Batignani, V. Bocci, W. M. Bonivento, B. Bottino, M. G. Boulay, J. Busto, M. Cadeddu, A. Caminata, N. Canci, A. Capra, S. Caprioli, M. Caravati, N. Cargioli, M. Carlini, P. Castello, P. Cavalcante, S. Cavuoti, S. Cebrian, J. M. Cela Ruiz, S. Chashin, A. Chepurnov, E. Chyhyrynets, L. Cifarelli, D. Cintas, M. Citterio, B. Cleveland, V. Cocco, E. Conde Vilda, L. Consiglio, S. Copello, G. Covone, M. Czubak, M. D’Aniello, S. D’Auria, M. D. Da Rocha Rolo, S. Davini, S. De Cecco, G. De Guido, D. De Gruttola, S. De Pasquale, G. De Rosa, G. Dellacasa, A. V. Derbin, A. Devoto, F. Di Capua, L. Di Noto, P. Di Stefano, G. Dolganov, F. Dordei, E. Ellingwood, T. Erjavec, S. Farenzena, M. Fernandez Diaz, G. Fiorillo, P. Franchini, D. Franco, N. Funicello, F. Gabriele, D. Gahan, C. Galbiati, G. Gallina, G. Gallus, M. Garbini, P. Garcia Abia, A. Gendotti, C. Ghiano, C. Giganti, G. K. Giovanetti, V. Goicoechea Casanueva, A. Gola, G. Grauso, G. Grilli di Cortona, A. Grobov, M. Gromov, M. Guan, M. Guerzoni, M. Gulino, C. Guo, B. R. Hackett, A. L. Hallin, A. Hamer, M. Haranczyk, T. Hessel, S. Hill, S. Horikawa, F. Hubaut, J. Hucker, T. Hugues, An. Ianni, V. Ippolito, C. Jillings, S. Jois, P. Kachru, A. A. Kemp, C. L. Kendziora, M. Kimura, I. Kochanek, K. Kondo, G. Korga, S. Koulosousas, A. Kubankin, M. Kuss, M. Kuźniak, M. La Commara, M. Lai, N. Lami, E. Le Guirriec, E. Leason, A. Leoni, L. Lidey, F. Lippi, M. Lissia, L. Luzzi, O. Lychagina, N. Maccioni, O. Macfadyen, I. N. Machulin, S. Manecki, I. Manthos, L. Mapelli, A. Margotti, S. M. Mari, C. Mariani, J. Maricic, A. Marini, M. Martínez, C. J. Martoff, M. Mascia, A. Masoni, G. Matteucci, K. Mavrokoridis, C. Maxia, A. B. McDonald, A. Messina, R. Milincic, A. Mitra, A. Moharana, S. Moioli, J. Monroe, E. Moretti, M. Morrocchi, T. Mróz, V. N. Muratova, C. Muscas, P. Musico, R. Nania, M. Nessi, K. Nikolopoulos, J. Nowak, K. Olchansky, A. Oleinik, V. Oleynikov, P. Organtini, A. Ortiz de Solórzano, L. Pagani, M. Pallavicini, L. Pandola, E. Pantic, E. Paoloni, G. Paternoster, P. A. Pegoraro, K. Pelczar, L. A. Pellegrini, C. Pellegrino, V. Pesudo, S. Piacentini, L. Pietrofaccia, N. Pino, A. Pocar, D. M. Poehlmann, S. Pordes, P. Pralavorio, D. Price, F. Ragusa, Y. Ramachers, M. Razeti, A. L. Renshaw, M. Rescigno, F. Retiere, L. P. Rignanese, C. Ripoli, A. Rivetti, A. Roberts, C. Roberts, J. Rode, G. Rogers, L. Romero, M. Rossi, A. Rubbia, M. A. Sabia, G. M. Sabiu, P. Salomone, E. Sandford, S. Sanfilippo, D. Santone, R. Santorelli, C. Savarese, E. Scapparone, G. Schillaci, F. Schukman, G. Scioli, M. Simeone, P. Skensved, M. D. Skorokhvatov, O. Smirnov, T. Smirnova, B. Smith, F. Spadoni, M. Spangenberg, R. Stefanizzi, A. Steri, V. Stornelli, S. Stracka, M. Stringer, S. Sulis, A. Sung, Y. Suvorov, A. M. Szelc, R. Tartaglia, A. Taylor, J. Taylor, S. Tedesco, G. Testera, K. Thieme, T. N. Thorpe, A. Tonazzo, A. Tricomi, E. V. Unzhakov, T. Vallivilayil John, M. Van Uffelen, T. Viant, S. Viel, R. B. Vogelaar, J. Vossebeld, M. Wada, M. B. Walczak, H. Wang, Y. Wang, S. Westerdale, L. Williams, I. Wingerter-Seez, R. Wojaczyński, Ma. M. Wojcik, T. Wright, Y. Xie, C. Yang, A. Zabihi, P. Zakhary, A. Zani, A. Zichichi, G. Zuzel, M. P. Zykova, and DarkSide-20k Collaboration

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The Aria cryogenic distillation plant, located in Sardinia, Italy, is a key component of the DarkSide-20k experimental program for WIMP dark matter searches at the INFN Laboratori Nazionali del Gran Sasso, Italy. Aria is designed to purify the argon, extracted from underground wells in Colorado, USA, and used as the DarkSide-20k target material, to detector-grade quality. In this paper, we report the first measurement of argon isotopic separation by distillation with the 26 m tall Aria prototype. We discuss the measurement of the operating parameters of the column and the observation of the simultaneous separation of the three stable argon isotopes: $${}^{36}\hbox {Ar}$$ 36 Ar , $${}^{38}\textrm{Ar}$$ 38 Ar , and $${}^{40}\textrm{Ar}$$ 40 Ar . We also provide a detailed comparison of the experimental results with commercial process simulation software. This measurement of isotopic separation of argon is a significant achievement for the project, building on the success of the initial demonstration of isotopic separation of nitrogen using the same equipment in 2019.

Published
2023
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15. Sedimentation and rheological behavior of reactive and non-reactive magnesium hydroxide pulps for industrial spray dryer processing

Author

E. C. Campos, D. H. S. Chaves, C. M. F. Santos, S. D. F. Rocha, and V. S. Birchal

Subjects
physical-chemical characterization, rheology, sedimentation, stability, structural particle arrangements, Engineering (General). Civil engineering (General), TA1-2040
Abstract

Abstract Two different reactive concentrated magnesium hydroxide (HM) pulps, produced in a lab reactor mill, and a synthetic and non-reactive HM-pulp, for comparative analyses, have been prepared and studied. Sodium polyacrylate was selected as a dispersant for improving the HM pulp fluidity, with concentrations varying from 0.42% to 2.0% on a dry basis. The two reactive pulps differed from each other mainly by the impurity level and for both, a residual MgO amount was detected, implying that the hydration reaction could proceed. Results (with and without dispersant) confirmed the formation of particle clusters as HM concentration rose until a critical value, above which the pulp behaved as a solid. Reactive HM-pulps with high impurities may represent a limiting factor in the drying operation. Among all HM-pulps studied, the purest reactive pulp with 1% dispersant presented the best flow behavior making this reactive pulp the most suitable to be tested in a pilot spray dryer.

Published
2023
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16. Effect of yeast species and processing on intestinal microbiota of Atlantic salmon (Salmo salar) fed soybean meal-based diets in seawater

Author

Jeleel O. Agboola, Sérgio D. C. Rocha, Dominic D. Mensah, Jon Ø. Hansen, Ove Øyås, David Lapeña, Liv T. Mydland, Magnus Ø. Arntzen, Svein J. Horn, and Margareth Øverland

Subjects
Cyberlindnera jadinii, Wickerhamomyces anomalus, Gut microbiota, Predicted metabolic capacity, SBMIE, Microbial diversity, Veterinary medicine, SF600-1100, Microbiology, QR1-502
Abstract

Abstract Background Yeasts are gaining attention as alternative ingredients in aquafeeds. However, the impact of yeast inclusion on modulation of intestinal microbiota of fish fed plant-based ingredients is limited. Thus, the present study investigates the effects of yeast and processing on composition, diversity and predicted metabolic capacity of gut microbiota of Atlantic salmon smolt fed soybean meal (SBM)-based diet. Two yeasts, Cyberlindnera jadinii (CJ) and Wickerhamomyces anomalus (WA), were produced in-house and processed by direct heat-inactivation with spray-drying (ICJ and IWA) or autolyzed at 50 °C for 16 h, followed by spray-drying (ACJ and AWA). In a 42-day feeding experiment, fish were fed one of six diets: a fishmeal (FM)-based diet, a challenging diet with 30% SBM and four other diets containing 30% SBM and 10% of each of the four yeast products (i.e., ICJ, ACJ, IWA and AWA). Microbial profiling of digesta samples was conducted using 16S rRNA gene sequencing, and the predicted metabolic capacities of gut microbiota were determined using genome-scale metabolic models. Results The microbial composition and predicted metabolic capacity of gut microbiota differed between fish fed FM diet and those fed SBM diet. The digesta of fish fed SBM diet was dominated by members of lactic acid bacteria, which was similar to microbial composition in the digesta of fish fed the inactivated yeasts (ICJ and IWA diets). Inclusion of autolyzed yeasts (ACJ and AWA diets) reduced the richness and diversity of gut microbiota in fish. The gut microbiota of fish fed ACJ diet was dominated by the genus Pediococcus and showed a predicted increase in mucin O-glycan degradation compared with the other diets. The gut microbiota of fish fed AWA diet was highly dominated by the family Bacillaceae. Conclusions The present study showed that dietary inclusion of FM and SBM differentially modulate the composition and predicted metabolic capacity of gut microbiota of fish. The inclusion of inactivated yeasts did not alter the modulation caused by SBM-based diet. Fish fed ACJ diet increased relative abundance of Pediococcus, and mucin O-glycan degradation pathway compared with the other diets.

Published
2023
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23. Volatile compounds from soybeans under multiple on herbivores infestations attract the predatory mite Neoseiulus californicus (Acari: Phytoseiidae)

Author

D. D. D. Rocha, B. L. F. Santos, J. O. F. Melo, P. T. Nascimento, and M. A. M. Fadini

Subjects
indirect induced defense, chemical ecology, biological control, plant resistance, pest management, Science, Biology (General), QH301-705.5, Zoology, QL1-991, Botany, QK1-989
Abstract

Abstract Plant-induced resistance can be an important component of soybean mites biological control programs. This work evaluates the preference of predatory mite Neoseiulus californicus (Acari: Phytoseiidae) to soybean plants under single and multiple herbivory conditions by two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae), and velvetbean caterpillar Anticarsia gemmatalis (Lepidoptera: Noctuidae). Using a Y olfactometer, the following scenarios were evaluated: soybean with no infestation and soybean infested with A. gemmatalis; soybean infested with T. urticae and A. gemmatalis, and soybean infested with T. urticae and with both T. urticae and A. gemmatalis. Volatile compounds released by plants were analyzed and identified by a Trace GC Ultra gas chromatograph coupled to a mass spectrometer with a solid phase micro-extraction ion-trap. The predatory mite N. californicus preferred soybean plants infested with T. urticae compared to those infested with A. gemmatalis. Multiple infestation did not interfere with its preference to T. urticae. Multiple herbivory of T. urticae and A. gemmatalis modified the chemical profile of volatile compounds emitted by soybean plants. However, it did not interfere with the search behavior of N. californicus. Out of the 29 identified compounds only five promoted predatory mite response. Thus, regardless of single or multiple herbivory by T. urticae with or without A. gemmatalis, the indirect induced resistance mechanisms operate similarly. As such, this mechanism contributes to an increase in the encounter rate between predator and prey for N. Californicus and T. urticae, and the efficacy of biological control of mites on soybean.

Published
2023
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25. Insecticide paints: a new community strategy for controlling dengue and zika mosquito vectors in Cabo Verde

Author

Gómez, Lara Ferrero, primary, Rocha, Hélio D. Ribeiro, additional, Torró, Ignacio Gil, additional, Pérez, Irene Serafín, additional, Mendes, Deinilson Conselheiro, additional, Silva, Keily L. Fonseca, additional, Monteiro, Davidson D. Sousa Rocha, additional, Dos Reis, Jailson P. Tavares, additional, Leal, Silvânia Veiga, additional, Soulé, Luis F. Vitória, additional, Fortes, Jailton C., additional, Mendonça, Maria da Luz Lima, additional, Mendez, Eva Caballero, additional, and Hernández, Basilio Valladares, additional

Published
2024
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26. Effects of Human Observer Presence on Pain Assessment Using Facial Expressions in Rabbits

Author

Renata H Pinho, André A Justo, Daniela S Cima, Mariana W Fonseca, Bruno W Minto, Fabiana D L Rocha, Matthew C Leach, and Stelio P L Luna

Subjects
Animal Science and Zoology, Original Research
Abstract

The goal of this study was to evaluate the effect of a human observer on Rabbit Grimace Scale (RbtGS) scores. The study scored video footage taken of 28 rabbits before and after orthopedic surgery, as follows: 24 h before surgery ( baseline), 1 h after surgery ( pain), 3 h after analgesia administration ( analgesia), and 24 h after surgery ( 24h) in the presence and absence of an observer. Videos were assessed twice in random order by 3 evaluators who were blind to the collection time and the presence or absence of an observer. Responses to pain and analgesia were evaluated by comparing the 4 time points using the Friedman test, followed by the Dunn test. The influence of the presence or absence of the observer at each time point was evaluated using the Wilcoxon test. Intra- and interrater reliabilities were estimated using the intraclass correlation coefficient. The scale was responsive to pain, as the scores increased after surgery and had decreased by 24 h after surgery. The presence of the observer reduced significantly the RbtGS scores (median and range) at pain (present, 0.75, 0 to 1.75; absent, 1, 0 to 2) and increased the scores at baseline (present, 0.2, 0 to 2; absent, 0, 0 to 2) and 24h after surgery (present, 0.33, 0 to 1.75; absent, 0.2, 0 to 1.5). The intrarater reliability was good (0.69) to very good (0.82) and interrater reliability was moderate (0.49) to good (0.67). Thus, the RbtGS appeared to detect pain when scored from video footage of rabbits before and after orthopedic surgery. In the presence of the observer, the pain scores were underestimated at the time considered to be associated with the greatest pain and overestimated at the times of little or no pain.

Published
2023
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30. Modulation of Atlantic salmon (Salmo salar) gut microbiota composition and predicted metabolic capacity by feeding diets with processed black soldier fly (Hermetia illucens) larvae meals and fractions

Author

Pabodha Weththasinghe, Sérgio D. C. Rocha, Ove Øyås, Leidy Lagos, Jon Ø. Hansen, Liv T. Mydland, and Margareth Øverland

Subjects
Black soldier fly, Full-fat insect meal, Atlantic salmon, Veterinary medicine, digestive, oral, and skin physiology, fungi, Defatted insect meal, Insect exoskeleton, General Medicine, Gut microbiota, digestive system, Microbiology, QR1-502, Insect oil, Predicted microbial metabolic capacity, SF600-1100, De-chitinized insect meal, Research Article
Abstract

BackgroundBlack soldier fly (Hermetia illucens) is a promising insect species to use as a novel ingredient in fish feeds. Black soldier fly larvae consists of three major fractions, namely protein, lipid, and exoskeleton. These fractions contain bioactive compounds that can modulate the gut microbiota in fish such as antimicrobial peptides, lauric acid, and chitin. However, it is not certain how, or which fractions of black solider fly would affect gut microbiota in fish. In the present study, black soldier fly larvae were processed into three different meals (full-fat, defatted and de-chitinized) and two fractions (oil and exoskeleton), and included in diets for Atlantic salmon (Salmo salar). Atlantic salmon pre-smolts were fed with these diets in comparison with a commercial-like control diet for eight weeks to investigate the effects of insect meals and fractions on the composition and predicted metabolic capacity of gut microbiota. The gut microbiota was profiled by 16S rRNA gene sequencing, and the predicted metabolic capacities of gut microbiota were determined using genome-scale metabolic models.ResultsThe inclusion of insect meals and fractions decreased abundance ofProteobacteriaand increased abundance ofFirmicutesin salmon gut. The diets that contained insect chitin, i.e., insect meals or exoskeleton diets, increased abundance of chitinolytic bacteria including lactic acid bacteria andActinomycesin salmon gut, with fish fed full-fat meal diet showing the highest abundances. The diets that contained insect lipids, i.e., insect meals and oil diets enrichedBacillaceaein fish gut. The fish fed diets containing full-fat insect meal had a unique gut microbiota composition dominated by beneficial lactic acid bacteria andActinomyces,and showed a predicted increase in mucin degradation compared to the other diets.ConclusionsThe present results showed that the dietary inclusion of insect meals and fractions can differently modulate the composition and predicted metabolic capacity of gut microbiota in Atlantic salmon pre-smolts. The use of full-fat black soldier fly larvae meal in diets for salmon is more favorable for beneficial modulation of gut microbiota than larvae processed by separation of lipid or exoskeleton fractions.

Published
2022

33. IMPLEMENTAÇÃO DE MELHORIA PARA A REDUÇÃO DE CUSTOS NA PRODUÇÃO DE PEÇAS DE PREPARO NA FUNDIÇÃO EM MÁQUINA LPDC

Author

Rabelo, Ian Dos S. and Siomara D. Da Rocha

Abstract

Durante a caminhada profissional e pessoal fazemos de tudo pra economizar e reduzir custos durante nossas compras, investimentos e melhorias em nossos projetos e objetivos (como reformas, por exemplo). Na indústria não é diferente, as empresas também fazem o máximo para reduzir custos e gastos desnecessários dos setores de sua responsabilidade, como por exemplo, no processo de produção de fundição industrial, que é o nosso objeto de estudo. Desse modo foi proposta uma redução de custos e até mesmo melhoria de segurança em uma máquina de produção industrial chamada LPDC (Low Pressure Die Casting). Os resultados demonstraram potenciais bônus nas condições de qualidade e redução de custos.

Published
2022
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35. Enhanced Stability of Scorodite in Oxic and Anoxic Systems via Surface Coating with Hydroxyapatite and Fluorapatite

Author

Sônia D. F. Rocha, Lydia Katsarou, and George P. Demopoulos

Subjects
Geology, Geotechnical Engineering and Engineering Geology, arsenic wastes, scorodite, encapsulation, hydroxyapatite, fluorapatite, crystallization
Abstract

With the objective of enhancing the stability of scorodite, its encapsulation with hydroxyapatite (Ca5(PO4)3OH) (HAP) and fluorapatite (Ca5(PO4)3F) (FAP) surface coatings, the two most stable of the calcium phosphates, inert to pH and redox potential variations, are presented in this work. The experimental work includes: (1) determination of the metastable zone for HAP and FAP precipitation, (2) the synthesis of crystalline scorodite under atmospheric conditions using hydrothermal scorodite seed and its characterization, (3) the coating of scorodite with hydroxyapatite and fluorapatite with supersaturation-controlled heterogeneous crystallization, and (4) the long-term stability of the encapsulated scorodite solids. Hydroxyapatite and fluorapatite were prepared with homogeneous precipitation from a metastable solution to which reagents were added at a controlled flow rate. Crystalline scorodite was produced with seeding precipitation and encapsulated with a direct apatite (HAP or FAP) deposition that was controlled by adjusting the pH and reagent addition. The stability tests in oxic and anoxic environments over the pH range of 5–9 showed the release of arsenic from the apatite-coated scorodite to be much lower than from naked scorodite, thereby demonstrating that apatite-based encapsulation of hazardous materials is technically feasible and merits further consideration for development into an arsenic stabilizing technology.

Published
2022
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36. Morphological, cellular, and molecular basis of brain infection in COVID-19 patients

Author

Fernanda Crunfli, Victor C. Carregari, Flavio P. Veras, Lucas S. Silva, Mateus Henrique Nogueira, André Saraiva Leão Marcelo Antunes, Pedro Henrique Vendramini, Aline Gazzola Fragnani Valença, Caroline Brandão-Teles, Giuliana da Silva Zuccoli, Guilherme Reis-de-Oliveira, Lícia C. Silva-Costa, Verônica Monteiro Saia-Cereda, Bradley J. Smith, Ana Campos Codo, Gabriela F de Souza, Stéfanie P. Muraro, Pierina Lorencini Parise, Daniel A. Toledo-Teixeira, Ícaro Maia Santos de Castro, Bruno Marcel Melo, Glaucia M. Almeida, Egidi Mayara Silva Firmino, Isadora Marques Paiva, Bruna Manuella Souza Silva, Rafaela Mano Guimarães, Niele D. Mendes, Raíssa L. Ludwig, Gabriel P. Ruiz, Thiago L. Knittel, Gustavo G. Davanzo, Jaqueline Aline Gerhardt, Patrícia Brito Rodrigues, Julia Forato, Mariene Ribeiro Amorim, Natália S. Brunetti, Matheus Cavalheiro Martini, Maíra Nilson Benatti, Sabrina S. Batah, Li Siyuan, Rafael B. João, Ítalo K. Aventurato, Mariana Rabelo de Brito, Maria J. Mendes, Beatriz A. da Costa, Marina K. M. Alvim, José Roberto da Silva Júnior, Lívia L. Damião, Iêda Maria P. de Sousa, Elessandra D. da Rocha, Solange M. Gonçalves, Luiz H. Lopes da Silva, Vanessa Bettini, Brunno M. Campos, Guilherme Ludwig, Lucas Alves Tavares, Marjorie Cornejo Pontelli, Rosa Maria Mendes Viana, Ronaldo B. Martins, Andre Schwambach Vieira, José Carlos Alves-Filho, Eurico Arruda, Guilherme Gozzoli Podolsky-Gondim, Marcelo Volpon Santos, Luciano Neder, André Damasio, Stevens Rehen, Marco Aurélio Ramirez Vinolo, Carolina Demarchi Munhoz, Paulo Louzada-Junior, Renê Donizeti Oliveira, Fernando Q. Cunha, Helder I. Nakaya, Thais Mauad, Amaro Nunes Duarte-Neto, Luiz Fernando Ferraz da Silva, Marisa Dolhnikoff, Paulo Hilario Nascimento Saldiva, Alessandro S. Farias, Fernando Cendes, Pedro Manoel M. Moraes-Vieira, Alexandre T. Fabro, Adriano Sebollela, José L. Proença-Modena, Clarissa L. Yasuda, Marcelo A. Mori, Thiago M. Cunha, and Daniel Martins-de-Souza

Subjects
Post-Acute COVID-19 Syndrome, Multidisciplinary, SARS-CoV-2, Astrocytes, Central Nervous System Viral Diseases, Brain, COVID-19, Humans
Abstract

Although increasing evidence confirms neuropsychiatric manifestations associated mainly with severe COVID-19 infection, long-term neuropsychiatric dysfunction (recently characterized as part of “long COVID-19” syndrome) has been frequently observed after mild infection. We show the spectrum of cerebral impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, ranging from long-term alterations in mildly infected individuals (orbitofrontal cortical atrophy, neurocognitive impairment, excessive fatigue and anxiety symptoms) to severe acute damage confirmed in brain tissue samples extracted from the orbitofrontal region (via endonasal transethmoidal access) from individuals who died of COVID-19. In an independent cohort of 26 individuals who died of COVID-19, we used histopathological signs of brain damage as a guide for possible SARS-CoV-2 brain infection and found that among the 5 individuals who exhibited those signs, all of them had genetic material of the virus in the brain. Brain tissue samples from these five patients also exhibited foci of SARS-CoV-2 infection and replication, particularly in astrocytes. Supporting the hypothesis of astrocyte infection, neural stem cell–derived human astrocytes in vitro are susceptible to SARS-CoV-2 infection through a noncanonical mechanism that involves spike–NRP1 interaction. SARS-CoV-2–infected astrocytes manifested changes in energy metabolism and in key proteins and metabolites used to fuel neurons, as well as in the biogenesis of neurotransmitters. Moreover, human astrocyte infection elicits a secretory phenotype that reduces neuronal viability. Our data support the model in which SARS-CoV-2 reaches the brain, infects astrocytes, and consequently, leads to neuronal death or dysfunction. These deregulated processes could contribute to the structural and functional alterations seen in the brains of COVID-19 patients.

Published
2022
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37. Is Edema Zone Volume Associated With Ki-67 Index in Glioblastoma Patients?

Author

Ricardo Caramanti, Raysa M Aprígio, Carlos E D`Aglio Rocha, Dionei F Morais, Mário J Góes, Feres Chaddad-Neto, and Waldir A Tognola

Subjects
General Engineering
Abstract

Introduction Despite all the progress with genetic mapping and multimodal treatment, the prognosis of Glioblastoma multiforme (GBM) remains poor, with median overall survival (OS) of only 12 to 15 months. Several studies showed correlations between glioblastoma clinic and prognosis factors; however, it doesn`t occur with tumor radiological features. The purpose of this study is to determine possible correlations between the volumetric analysis of glioblastoma compartments and the proliferation index represented by Ki-67. Methods We performed a retrospective analysis of MRI studies of 70 patients with glioblastoma multiforme acquired up to one week before surgery. The tumor compartments were divided into enhancing zone; edema zone and tumor total zone. Each compartment was submitted to volumetric analysis using Horos Project software. A linear regression model was used to assess correlations between the ki-67 index and the volume of each compartment with a p-value of 0.05. Results The male/female ratio in our study was 1.7:1, at a mean age of 60.7 ± 14.6 years. Tumor predominant location was the temporal lobe with 25% of cases and cystic morphology was present in 17%. The median of Ki-67 was 40%. The average tumor compartment volume was 40 cm

Published
2022
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45. A178 ELUCIDATING THE ROLE OF THE LEUCINE-RICH REPEAT KINASE 2 G2019S MUTATION IN CROHN’S DISEASE PATHOGENESIS USING A CITROBACTER RODENTIUM INFECTIOUS COLITIS MODEL

Author

B Samman, J Yadav, G Bayer, E G Foerster, L Chen, J D B Rocha, S E Girardin, and D J Philpott

Abstract

Background Associations have been found linking certain LRRK2 kinase domain gain-of-function variants, such as G2019S, to the development of Crohn’s disease and Parkinson’s disease, yet their exact roles in pathogenesis remains elusive. LRRK2 is most robustly expressed in circulating and tissue-resident immune cells, such as neutrophils, lymphocytes, and macrophages. Myeloid cells deficient in LRRK2 exhibit defective antimicrobial responses, such as reduced production of reactive oxygen species in response to microbial stimuli and reduced bactericidal activity in response to infection. As an enteric colitis-inducing extracellular pathogen, Citrobacter rodentium can help us better understand the consequences of LRRK2 kinase hyperactivity on intestinal inflammation by correlating pathogen burden with key host response parameters over the course of infection. Purpose To investigate the effects of the Crohn’s and Parkinson’s disease-associated Lrrk2 G2019S hyper-kinase mutation on pathogen burden and colonic inflammation in the context of C. rodentium-induced infectious colitis. Method Wild-type and Lrrk2 G2019S mutant mice (7-8 weeks old) were fasted for 4 hours then infected with 1 x 108 CFU of C. rodentium in a 3% NaHCO3 solution by oral gavage. Body weight, faecal pathogen burden, and faecal lipocalin-2 (Lcn2) concentrations were measured at 2, 4, 7, 9, 10, 12, and 14 days post-infection (DPI). Systemic pathogen burden (as measured in the mesenteric lymph nodes and spleen), colon length, colonic inflammatory gene expression, and histopathological scoring were assessed at 7, 10, and 14 DPI. Result(s) While G2019S mice exhibited marginally higher C. rodentium loads at certain timepoints, no significant differences were found in overall pathogen burden or pathogen clearance rates between genotypes over the first 14 days of infection. Faecal pathogen load peaked at 7-9 DPI in both WT and G2019S mice, which correlated with detectable levels of C. rodentium in the mesenteric lymph nodes and spleens of some mice at 7 DPI. Lcn2 secretion and the expression of inflammatory and antimicrobial genes of interest were induced robustly over the course of infection. They peaked and ebbed at timepoints correlating well with pathogen burden; however, no significant differences were observed between WT and G2019S mutant mice at the various timepoints assessed. Conclusion(s) Mice expressing the G2019S Lrrk2 mutation exhibit neither defective pathogen control nor deleterious hyperinflammation – compared to WT mice – when infected with C. rodentium. Further research will aim to investigate the role of this Lrrk2 variant in additional models of intestinal inflammation. Please acknowledge all funding agencies by checking the applicable boxes below CCC, CIHR Disclosure of Interest None Declared

Published
2023
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