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314 results on '"Marie, Guillaume"'

1. LLaMandement: Large Language Models for Summarization of French Legislative Proposals

Author

Gesnouin, Joseph, Tannier, Yannis, Da Silva, Christophe Gomes, Tapory, Hatim, Brier, Camille, Simon, Hugo, Rozenberg, Raphael, Woehrel, Hermann, Yakaabi, Mehdi El, Binder, Thomas, Marie, Guillaume, Caron, Emilie, Nogueira, Mathile, Fontas, Thomas, Puydebois, Laure, Theophile, Marie, Morandi, Stephane, Petit, Mael, Creissac, David, Ennouchy, Pauline, Valetoux, Elise, Visade, Celine, Balloux, Severine, Cortes, Emmanuel, Devineau, Pierre-Etienne, Tan, Ulrich, Mac Namara, Esther, and Yang, Su

Subjects
Computer Science - Computation and Language, Computer Science - Artificial Intelligence
Abstract

This report introduces LLaMandement, a state-of-the-art Large Language Model, fine-tuned by the French government and designed to enhance the efficiency and efficacy of processing parliamentary sessions (including the production of bench memoranda and documents required for interministerial meetings) by generating neutral summaries of legislative proposals. Addressing the administrative challenges of manually processing a growing volume of legislative amendments, LLaMandement stands as a significant legal technological milestone, providing a solution that exceeds the scalability of traditional human efforts while matching the robustness of a specialized legal drafter. We release all our fine-tuned models and training data to the community., Comment: 21 pages, 9 figures

Published
2024

3. Towards automated brain aneurysm detection in TOF-MRA: open data, weak labels, and anatomical knowledge

Author

Di Noto, Tommaso, Marie, Guillaume, Tourbier, Sebastien, Alemán-Gómez, Yasser, Esteban, Oscar, Saliou, Guillaume, Cuadra, Meritxell Bach, Hagmann, Patric, and Richiardi, Jonas

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition
Abstract

Brain aneurysm detection in Time-Of-Flight Magnetic Resonance Angiography (TOF-MRA) has undergone drastic improvements with the advent of Deep Learning (DL). However, performances of supervised DL models heavily rely on the quantity of labeled samples, which are extremely costly to obtain. Here, we present a DL model for aneurysm detection that overcomes the issue with ''weak'' labels: oversized annotations which are considerably faster to create. Our weak labels resulted to be four times faster to generate than their voxel-wise counterparts. In addition, our model leverages prior anatomical knowledge by focusing only on plausible locations for aneurysm occurrence. We frst train and evaluate our model through cross-validation on an in-house TOF-MRA dataset comprising 284 subjects (170 females / 127 healthy controls / 157 patients with 198 aneurysms). On this dataset, our best model achieved a sensitivity of 83%, with False Positive (FP) rate of 0.8 per patient. To assess model generalizability, we then participated in a challenge for aneurysm detection with TOF-MRA data (93 patients, 20 controls, 125 aneurysms). On the public challenge, sensitivity was 68% (FP rate=2.5), ranking 4th/18 on the open leaderboard. We found no signifcant diference in sensitivity between aneurysm risk-of-rupture groups (p=0.75), locations (p=0.72), or sizes (p=0.15). Data, code and model weights are released under permissive licenses. We demonstrate that weak labels and anatomical knowledge can alleviate the necessity for prohibitively expensive voxel-wise annotations., Comment: Paper accepted as Original Article in the journal Neuroinformatics (https://link.springer.com/article/10.1007/s12021-022-09597-0)

Published
2021
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4. An anatomically-informed 3D CNN for brain aneurysm classification with weak labels

Author

Di Noto, Tommaso, Marie, Guillaume, Tourbier, Sébastien, Alemán-Gómez, Yasser, Saliou, Guillaume, Cuadra, Meritxell Bach, Hagmann, Patric, and Richiardi, Jonas

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Machine Learning
Abstract

A commonly adopted approach to carry out detection tasks in medical imaging is to rely on an initial segmentation. However, this approach strongly depends on voxel-wise annotations which are repetitive and time-consuming to draw for medical experts. An interesting alternative to voxel-wise masks are so-called "weak" labels: these can either be coarse or oversized annotations that are less precise, but noticeably faster to create. In this work, we address the task of brain aneurysm detection as a patch-wise binary classification with weak labels, in contrast to related studies that rather use supervised segmentation methods and voxel-wise delineations. Our approach comes with the non-trivial challenge of the data set creation: as for most focal diseases, anomalous patches (with aneurysm) are outnumbered by those showing no anomaly, and the two classes usually have different spatial distributions. To tackle this frequent scenario of inherently imbalanced, spatially skewed data sets, we propose a novel, anatomically-driven approach by using a multi-scale and multi-input 3D Convolutional Neural Network (CNN). We apply our model to 214 subjects (83 patients, 131 controls) who underwent Time-Of-Flight Magnetic Resonance Angiography (TOF-MRA) and presented a total of 111 unruptured cerebral aneurysms. We compare two strategies for negative patch sampling that have an increasing level of difficulty for the network and we show how this choice can strongly affect the results. To assess whether the added spatial information helps improving performances, we compare our anatomically-informed CNN with a baseline, spatially-agnostic CNN. When considering the more realistic and challenging scenario including vessel-like negative patches, the former model attains the highest classification results (accuracy$\simeq$95\%, AUROC$\simeq$0.95, AUPR$\simeq$0.71), thus outperforming the baseline., Comment: 11 pages, 2 figures, Paper accepted at the "Machine Learning in Clinical Neuroimaging" (MLCN) MICCAI workshop 2020 (https://mlcnws.com/)

Published
2020

5. The gas-phase formation mechanism of iodic acid as an atmospheric aerosol source

Author

Finkenzeller, Henning, Iyer, Siddharth, He, Xu-Cheng, Simon, Mario, Koenig, Theodore K., Lee, Christopher F., Valiev, Rashid, Hofbauer, Victoria, Amorim, Antonio, Baalbaki, Rima, Baccarini, Andrea, Beck, Lisa, Bell, David M., Caudillo, Lucía, Chen, Dexian, Chiu, Randall, Chu, Biwu, Dada, Lubna, Duplissy, Jonathan, Heinritzi, Martin, Kemppainen, Deniz, Kim, Changhyuk, Krechmer, Jordan, Kürten, Andreas, Kvashnin, Alexandr, Lamkaddam, Houssni, Lee, Chuan Ping, Lehtipalo, Katrianne, Li, Zijun, Makhmutov, Vladimir, Manninen, Hanna E., Marie, Guillaume, Marten, Ruby, Mauldin, Roy L., Mentler, Bernhard, Müller, Tatjana, Petäjä, Tuukka, Philippov, Maxim, Ranjithkumar, Ananth, Rörup, Birte, Shen, Jiali, Stolzenburg, Dominik, Tauber, Christian, Tham, Yee Jun, Tomé, António, Vazquez-Pufleau, Miguel, Wagner, Andrea C., Wang, Dongyu S., Wang, Mingyi, Wang, Yonghong, Weber, Stefan K., Nie, Wei, Wu, Yusheng, Xiao, Mao, Ye, Qing, Zauner-Wieczorek, Marcel, Hansel, Armin, Baltensperger, Urs, Brioude, Jérome, Curtius, Joachim, Donahue, Neil M., Haddad, Imad El, Flagan, Richard C., Kulmala, Markku, Kirkby, Jasper, Sipilä, Mikko, Worsnop, Douglas R., Kurten, Theo, Rissanen, Matti, and Volkamer, Rainer

Published
2023
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7. What Occurs within the Mangrove Ecosystems of the Douala Region in Cameroon? Exploring the Challenging Governance of Readily Available Woody Resources in the Wouri Estuary

Author

Bissonnette, Jean-François, primary, Dossa, Kossivi Fabrice, additional, Nsangou, Celestin Arnaud, additional, Satchie, Yangue Abidah, additional, Moussa, Haman, additional, Miassi, Yann Emmanuel, additional, Gravel, Nathalie, additional, Marie, Guillaume, additional, and Onguene, Raphaël, additional

Published
2024
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8. No Parley For Pirates: Federal Court (Canada) Grants Innovative Remedy To Combat Sports Piracy

Author

Ste-Marie, Guillaume Lavoie

Subjects
Television broadcasting of sports -- Cases -- Laws, regulations and rules, Piracy (Copyright) -- Cases, Company legal issue, Government regulation, Business, international
Abstract

In Rogers Media Inc et al v John Doe 1 et al, 2024 FC 1082, the Federal Court (Canada) (the Court) issued the first site-blocking judgment allowing the applicants to [...]

Published
2024

10. Synergistic HNO3–H2SO4–NH3 upper tropospheric particle formation

Author

Wang, Mingyi, Xiao, Mao, Bertozzi, Barbara, Marie, Guillaume, Rörup, Birte, Schulze, Benjamin, Bardakov, Roman, He, Xu-Cheng, Shen, Jiali, Scholz, Wiebke, Marten, Ruby, Dada, Lubna, Baalbaki, Rima, Lopez, Brandon, Lamkaddam, Houssni, Manninen, Hanna E., Amorim, António, Ataei, Farnoush, Bogert, Pia, Brasseur, Zoé, Caudillo, Lucía, De Menezes, Louis-Philippe, Duplissy, Jonathan, Ekman, Annica M. L., Finkenzeller, Henning, Carracedo, Loïc Gonzalez, Granzin, Manuel, Guida, Roberto, Heinritzi, Martin, Hofbauer, Victoria, Höhler, Kristina, Korhonen, Kimmo, Krechmer, Jordan E., Kürten, Andreas, Lehtipalo, Katrianne, Mahfouz, Naser G. A., Makhmutov, Vladimir, Massabò, Dario, Mathot, Serge, Mauldin, Roy L., Mentler, Bernhard, Müller, Tatjana, Onnela, Antti, Petäjä, Tuukka, Philippov, Maxim, Piedehierro, Ana A., Pozzer, Andrea, Ranjithkumar, Ananth, Schervish, Meredith, Schobesberger, Siegfried, Simon, Mario, Stozhkov, Yuri, Tomé, António, Umo, Nsikanabasi Silas, Vogel, Franziska, Wagner, Robert, Wang, Dongyu S., Weber, Stefan K., Welti, André, Wu, Yusheng, Zauner-Wieczorek, Marcel, Sipilä, Mikko, Winkler, Paul M., Hansel, Armin, Baltensperger, Urs, Kulmala, Markku, Flagan, Richard C., Curtius, Joachim, Riipinen, Ilona, Gordon, Hamish, Lelieveld, Jos, El-Haddad, Imad, Volkamer, Rainer, Worsnop, Douglas R., Christoudias, Theodoros, Kirkby, Jasper, Möhler, Ottmar, and Donahue, Neil M.

Published
2022
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11. Simulating Ips typographus L. outbreak dynamics and their influence on carbon balance estimates with ORCHIDEE r8627.

Author

Marie, Guillaume, Jeong, Jina, Jactel, Hervé, Petter, Gunnar, Cailleret, Maxime, McGrath, Matthew J., Bastrikov, Vladislav, Ghattas, Josefine, Guenet, Bertrand, Lansø, Anne Sofie, Naudts, Kim, Valade, Aude, Yue, Chao, and Luyssaert, Sebastiaan

Abstract

New (a)biotic conditions resulting from climate change are expected to change disturbance dynamics, such as windthrow, forest fires, droughts, and insect outbreaks, and their interactions. These unprecedented natural disturbance dynamics might alter the capability of forest ecosystems to buffer atmospheric CO2 increases, potentially leading forests to transform from sinks into sources of CO2. This study aims to enhance the ORCHIDEE land surface model to study the impacts of climate change on the dynamics of the bark beetle, Ips typographus, and subsequent effects on forest functioning. The Ips typographus outbreak model is inspired by previous work from Temperli et al. (2013) for the LandClim landscape model. The new implementation of this model in ORCHIDEE r8627 accounts for key differences between ORCHIDEE and LandClim: (1) the coarser spatial resolution of ORCHIDEE; (2) the higher temporal resolution of ORCHIDEE; and (3) the pre-existing process representation of windthrow, drought, and forest structure in ORCHIDEE. Simulation experiments demonstrated the capability of ORCHIDEE to simulate a variety of post-disturbance forest dynamics observed in empirical studies. Through an array of simulation experiments across various climatic conditions and windthrow intensities, the model was tested for its sensitivity to climate, initial disturbance, and selected parameter values. The results of these tests indicated that with a single set of parameters, ORCHIDEE outputs spanned the range of observed dynamics. Additional tests highlighted the substantial impact of incorporating Ips typographus outbreaks on carbon dynamics. Notably, the study revealed that modeling abrupt mortality events as opposed to a continuous mortality framework provides new insights into the short-term carbon sequestration potential of forests under disturbance regimes by showing that the continuous mortality framework tends to overestimate the carbon sink capacity of forests in the 20- to 50-year range in ecosystems under high disturbance pressure compared to scenarios with abrupt mortality events. This model enhancement underscores the critical need to include disturbance dynamics in land surface models to refine predictions of forest carbon dynamics in a changing climate. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Ammonium CI-Orbitrap: a tool for characterizing the reactivity of oxygenated organic molecules.

Author

Li, Dandan, Wang, Dongyu, Caudillo, Lucia, Scholz, Wiebke, Wang, Mingyi, Tomaz, Sophie, Marie, Guillaume, Surdu, Mihnea, Eccli, Elias, Gong, Xianda, Gonzalez-Carracedo, Loic, Granzin, Manuel, Pfeifer, Joschka, Rörup, Birte, Schulze, Benjamin, Rantala, Pekka, Perrier, Sébastien, Hansel, Armin, Curtius, Joachim, and Kirkby, Jasper

Subjects
MASS spectrometry, TIME-of-flight mass spectrometers, MASS spectrometers, ATMOSPHERIC ionization, ATMOSPHERIC aerosols, CHEMICAL ionization mass spectrometry
Abstract

Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges with respect to measuring organic vapors, uncertainties remain regarding the formation and fate of OOMs. The chemical ionization Orbitrap (CI-Orbitrap) mass spectrometer has recently been shown to be a powerful technique that is able to accurately identify gaseous organic compounds due to its greater mass resolution. Here, we present the ammonium-ion-based CI-Orbitrap (NH4+ -Orbitrap) as a technique capable of measuring a wide range of gaseous OOMs. The performance of the NH4+ -Orbitrap is compared with that of state-of-the-art mass spectrometers, including a nitrate-ion-based chemical ionization atmospheric pressure interface coupled to a time-of-flight mass spectrometer (NO3- -LTOF), a new generation of proton transfer reaction-TOF mass spectrometer (PTR3-TOF), and an iodide-based CI-TOF mass spectrometer equipped with a Filter Inlet for Gases and AEROsols (I- -CIMS). The instruments were deployed simultaneously in the Cosmic Leaving OUtdoors Droplets (CLOUD) chamber at the European Organization for Nuclear Research (CERN) during the CLOUD14 campaign in 2019. Products generated from α -pinene ozonolysis under various experimental conditions were simultaneously measured by the mass spectrometers. The NH4+ -Orbitrap was able to identify the widest range of OOMs (i.e., O ≥ 2), from less-oxidized species to highly oxygenated organic molecules (HOMs). Excellent agreement was found between the NH4+ -Orbitrap and the NO3- -LTOF with respect to characterizing HOMs and with the PTR3-TOF for the less-oxidized monomeric species. OOM concentrations measured by NH4+ -Orbitrap were estimated using calibration factors derived from the OOMs with high time-series correlations during the side-by-side measurements. As with the other mass spectrometry techniques used during this campaign, the detection sensitivity of the NH4+ -Orbitrap to OOMs is greatly affected by relative humidity, which may be related to changes in ionization efficiency and/or multiphase chemistry. Overall, this study shows that NH4+ -ion-based chemistry associated with the high mass resolution of the Orbitrap mass analyzer can measure almost all inclusive compounds. As a result, it is now possible to cover the entire range of compounds, which can lead to a better understanding of the oxidation processes. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Comparing methods of detecting and segmenting unruptured intracranial aneurysms on TOF-MRAS: The ADAM challenge

Author

Timmins, Kimberley M., van der Schaaf, Irene C., Bennink, Edwin, Ruigrok, Ynte M., An, Xingle, Baumgartner, Michael, Bourdon, Pascal, De Feo, Riccardo, Noto, Tommaso Di, Dubost, Florian, Fava-Sanches, Augusto, Feng, Xue, Giroud, Corentin, Group, Inteneural, Hu, Minghui, Jaeger, Paul F., Kaiponen, Juhana, Klimont, Michał, Li, Yuexiang, Li, Hongwei, Lin, Yi, Loehr, Timo, Ma, Jun, Maier-Hein, Klaus H., Marie, Guillaume, Menze, Bjoern, Richiardi, Jonas, Rjiba, Saifeddine, Shah, Dhaval, Shit, Suprosanna, Tohka, Jussi, Urruty, Thierry, Walińska, Urszula, Yang, Xiaoping, Yang, Yunqiao, Yin, Yin, Velthuis, Birgitta K., and Kuijf, Hugo J.

Published
2021
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14. Nitrate Radicals Suppress Biogenic New Particle Formation from Monoterpene Oxidation

Author

Li, Dandan, primary, Huang, Wei, additional, Wang, Dongyu, additional, Wang, Mingyi, additional, Thornton, Joel A., additional, Caudillo, Lucía, additional, Rörup, Birte, additional, Marten, Ruby, additional, Scholz, Wiebke, additional, Finkenzeller, Henning, additional, Marie, Guillaume, additional, Baltensperger, Urs, additional, Bell, David M., additional, Brasseur, Zoé, additional, Curtius, Joachim, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Gong, Xianda, additional, Hansel, Armin, additional, He, Xu-Cheng, additional, Hofbauer, Victoria, additional, Junninen, Heikki, additional, Krechmer, Jordan E., additional, Kürten, Andreas, additional, Lamkaddam, Houssni, additional, Lehtipalo, Katrianne, additional, Lopez, Brandon, additional, Ma, Yingge, additional, Mahfouz, Naser G. A., additional, Manninen, Hanna E., additional, Mentler, Bernhard, additional, Perrier, Sebastien, additional, Petäjä, Tuukka, additional, Pfeifer, Joschka, additional, Philippov, Maxim, additional, Schervish, Meredith, additional, Schobesberger, Siegfried, additional, Shen, Jiali, additional, Surdu, Mihnea, additional, Tomaz, Sophie, additional, Volkamer, Rainer, additional, Wang, Xinke, additional, Weber, Stefan K., additional, Welti, André, additional, Worsnop, Douglas R., additional, Wu, Yusheng, additional, Yan, Chao, additional, Zauner-Wieczorek, Marcel, additional, Kulmala, Markku, additional, Kirkby, Jasper, additional, Donahue, Neil M., additional, George, Christian, additional, El-Haddad, Imad, additional, Bianchi, Federico, additional, and Riva, Matthieu, additional

Published
2024
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15. Assessing the importance of nitric acid and ammonia for particle growth in the polluted boundary layer

Author

Marten, Ruby, primary, Xiao, Mao, additional, Wang, Mingyi, additional, Kong, Weimeng, additional, He, Xu-Cheng, additional, Stolzenburg, Dominik, additional, Pfeifer, Joschka, additional, Marie, Guillaume, additional, Wang, Dongyu S., additional, Elser, Miriam, additional, Baccarini, Andrea, additional, Lee, Chuan Ping, additional, Amorim, Antonio, additional, Baalbaki, Rima, additional, Bell, David M., additional, Bertozzi, Barbara, additional, Caudillo, Lucía, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Finkenzeller, Henning, additional, Heinritzi, Martin, additional, Lampimäki, Markus, additional, Lehtipalo, Katrianne, additional, Manninen, Hanna E., additional, Mentler, Bernhard, additional, Onnela, Antti, additional, Petäjä, Tuukka, additional, Philippov, Maxim, additional, Rörup, Birte, additional, Scholz, Wiebke, additional, Shen, Jiali, additional, Tham, Yee Jun, additional, Tomé, António, additional, Wagner, Andrea C., additional, Weber, Stefan K., additional, Zauner-Wieczorek, Marcel, additional, Curtius, Joachim, additional, Kulmala, Markku, additional, Volkamer, Rainer, additional, Worsnop, Douglas R., additional, Dommen, Josef, additional, Flagan, Richard C., additional, Kirkby, Jasper, additional, McPherson Donahue, Neil, additional, Lamkaddam, Houssni, additional, Baltensperger, Urs, additional, and El Haddad, Imad, additional

Published
2024
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16. Rapid growth of new atmospheric particles by nitric acid and ammonia condensation

Author

Wang, Mingyi, Kong, Weimeng, Marten, Ruby, He, Xu-Cheng, Chen, Dexian, Pfeifer, Joschka, Heitto, Arto, Kontkanen, Jenni, Dada, Lubna, Kürten, Andreas, Yli-Juuti, Taina, Manninen, Hanna E., Amanatidis, Stavros, Amorim, António, Baalbaki, Rima, Baccarini, Andrea, Bell, David M., Bertozzi, Barbara, Bräkling, Steffen, Brilke, Sophia, Murillo, Lucía Caudillo, Chiu, Randall, Chu, Biwu, De Menezes, Louis-Philippe, Duplissy, Jonathan, Finkenzeller, Henning, Carracedo, Loic Gonzalez, Granzin, Manuel, Guida, Roberto, Hansel, Armin, Hofbauer, Victoria, Krechmer, Jordan, Lehtipalo, Katrianne, Lamkaddam, Houssni, Lampimäki, Markus, Lee, Chuan Ping, Makhmutov, Vladimir, Marie, Guillaume, Mathot, Serge, Mauldin, Roy L., Mentler, Bernhard, Müller, Tatjana, Onnela, Antti, Partoll, Eva, Petäjä, Tuukka, Philippov, Maxim, Pospisilova, Veronika, Ranjithkumar, Ananth, Rissanen, Matti, Rörup, Birte, Scholz, Wiebke, Shen, Jiali, Simon, Mario, Sipilä, Mikko, Steiner, Gerhard, Stolzenburg, Dominik, Tham, Yee Jun, Tomé, António, Wagner, Andrea C., Wang, Dongyu S., Wang, Yonghong, Weber, Stefan K., Winkler, Paul M., Wlasits, Peter J., Wu, Yusheng, Xiao, Mao, Ye, Qing, Zauner-Wieczorek, Marcel, Zhou, Xueqin, Volkamer, Rainer, Riipinen, Ilona, Dommen, Josef, Curtius, Joachim, Baltensperger, Urs, Kulmala, Markku, Worsnop, Douglas R., Kirkby, Jasper, Seinfeld, John H., El-Haddad, Imad, Flagan, Richard C., and Donahue, Neil M.

Published
2020
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18. Exploration of new methods involved for the synthesis of PET tracers

Author

Marie, Guillaume

Subjects
547, QD Chemistry
Abstract

This work describes the development and the optimisation of microfluidic radiolabelling by using an Eckert & Ziegler device remotely controlled by a computer to perform the multistep synthesis of [18F]-fluoro-2-deoxy-D-glucose ([18F]-FDG). This device was then modified to control the fluidic transfers via flow of nitrogen and vacuum with the aid of a new one-way cassette system by using different concentrations of water for the Kryptofix solution. A new route was also explored to perform florbetaben ([18F]-BAY94- 9172), a potent Alzheimer’s disease PET tracer. Chapter 1 is an overview of positron emission tomography techniques to synthesise tracers. Chapter 2 is a brief introduction of the PETIC centre (Wales), where the fluoride-18 was delivered to produce [18F]-FDG. Chapter 3 describes the reaction of the [K+⊂2.2.2]18F− complex on mannose triflate and the variety of products formed. The Eckert & Ziegler platform was furnished with a cassette module and a microfluidic tubing to perform the radiolabelling fluorination of mannose triflate to the tetraacetate [18F]-deoxy-D-glucose and [18F]-FDG. Chapter 4 is focused on the modifications on the Eckert & Ziegler modules by using 1-way cassettes to limit the use of mechanical valves. [18F]-FDG was synthesised via a semiautomated procedure by limiting the number of modules present in the hot cell. Chapter 5 is an investigation for the preparation of several triethylene glycol derivatives following the syntheses of Kryptofix [2.2.2]. The use of triethylene glycol chain will be essential for the synthesis of the Florbetaben precursor. The Chapter 6 is the exploration of a new synthetic route leading to the precursor of florbetaben.

Published
2014

24. Ammonium CI-Orbitrap: a tool for characterizing the reactivity of oxygenated organic molecules

Author

Li, Dandan, primary, Wang, Dongyu, additional, Caudillo, Lucia, additional, Scholz, Wiebke, additional, Wang, Mingyi, additional, Tomaz, Sophie, additional, Marie, Guillaume, additional, Surdu, Mihnea, additional, Eccli, Elias, additional, Gong, Xianda, additional, Gonzalez-Carracedo, Loic, additional, Granzin, Manuel, additional, Pfeifer, Joschka, additional, Rörup, Birte, additional, Schulze, Benjamin, additional, Rantala, Pekka, additional, Perrier, Sébastien, additional, Hansel, Armin, additional, Curtius, Joachim, additional, Kirkby, Jasper, additional, Donahue, Neil M., additional, George, Christian, additional, El-Haddad, Imad, additional, and Riva, Matthieu, additional

Published
2023
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25. Supplementary material to "Ammonium CI-Orbitrap: a tool for characterizing the reactivity of oxygenated organic molecules"

Author

Li, Dandan, primary, Wang, Dongyu, additional, Caudillo, Lucia, additional, Scholz, Wiebke, additional, Wang, Mingyi, additional, Tomaz, Sophie, additional, Marie, Guillaume, additional, Surdu, Mihnea, additional, Eccli, Elias, additional, Gong, Xianda, additional, Gonzalez-Carracedo, Loic, additional, Granzin, Manuel, additional, Pfeifer, Joschka, additional, Rörup, Birte, additional, Schulze, Benjamin, additional, Rantala, Pekka, additional, Perrier, Sébastien, additional, Hansel, Armin, additional, Curtius, Joachim, additional, Kirkby, Jasper, additional, Donahue, Neil M., additional, George, Christian, additional, El-Haddad, Imad, additional, and Riva, Matthieu, additional

Published
2023
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26. An intercomparison study of four different techniques for measuring the chemical composition of nanoparticles

Author

Caudillo, Lucía, primary, Surdu, Mihnea, additional, Lopez, Brandon, additional, Wang, Mingyi, additional, Thoma, Markus, additional, Bräkling, Steffen, additional, Buchholz, Angela, additional, Simon, Mario, additional, Wagner, Andrea C., additional, Müller, Tatjana, additional, Granzin, Manuel, additional, Heinritzi, Martin, additional, Amorim, Antonio, additional, Bell, David M., additional, Brasseur, Zoé, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Finkenzeller, Henning, additional, He, Xu-Cheng, additional, Lamkaddam, Houssni, additional, Mahfouz, Naser G. A., additional, Makhmutov, Vladimir, additional, Manninen, Hanna E., additional, Marie, Guillaume, additional, Marten, Ruby, additional, Mauldin, Roy L., additional, Mentler, Bernhard, additional, Onnela, Antti, additional, Petäjä, Tuukka, additional, Pfeifer, Joschka, additional, Philippov, Maxim, additional, Piedehierro, Ana A., additional, Rörup, Birte, additional, Scholz, Wiebke, additional, Shen, Jiali, additional, Stolzenburg, Dominik, additional, Tauber, Christian, additional, Tian, Ping, additional, Tomé, António, additional, Umo, Nsikanabasi Silas, additional, Wang, Dongyu S., additional, Wang, Yonghong, additional, Weber, Stefan K., additional, Welti, André, additional, Zauner-Wieczorek, Marcel, additional, Baltensperger, Urs, additional, Flagan, Richard C., additional, Hansel, Armin, additional, Kirkby, Jasper, additional, Kulmala, Markku, additional, Lehtipalo, Katrianne, additional, Worsnop, Douglas R., additional, Haddad, Imad El, additional, Donahue, Neil M., additional, Vogel, Alexander L., additional, Kürten, Andreas, additional, and Curtius, Joachim, additional

Published
2023
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28. Simulating Bark Beetle Outbreak Dynamics and their Influence on Carbon Balance Estimates with ORCHIDEE r7791

Author

Marie, Guillaume, Jeong, Jina, Jactel, Hervé, Petter, Gunnar, Cailleret, Maxime, McGrath, Matthew, Bastrikov, Vladislav, Ghattas, Josefine, Guenet, Bertrand, Lansø, Anne-Sofie, Naudts, Kim, Valade, Aude, Yue, Chao, and Luyssaert, Sebastiaan

Abstract

New (a)biotic conditions, resulting from climate change, are expected to change disturbance dynamics, e.g., wind throw, forest fires and insect outbreaks, and their interactions. Unprecedented natural disturbance dynamics might alter the capability of forest ecosystems to buffer atmospheric CO2 increases in the atmosphere, even leading to the risk that forests transform from sinks into sources of CO2. This study aims to enhance the capability of the ORCHIDEE land surface model to study the impacts of climate change on bark beetle dynamics and subsequent effects on forest functioning. The bark beetle outbreak model is based on previous work by Temperli et al. 2013 for the LandClim landscape model. The new implementation of this model in ORCHIDEE r7791 accounts for the following differences between ORCHIDEE and LandClim: (1) the coarser spatial resolution of ORCHIDEE, (2) the higher temporal resolution of ORCHIDEE, and (3) the pre-existing process representation of wind throw, drought, and forest structure in ORCHIDEE. Qualitative evaluation demonstrated the model’s ability to simulate a wide range of observed post-disturbance forest dynamics: (1) resistance to bark beetle infestation even in the presence of windthrow events; (2) slow transition (3–7 years) from an endemic into an epidemic bark beetle population following medium intensity window events at cold locations; and (3) fast transition (1–3 years) from endemic to epidemic triggered by strong windthrow events. Although all simulated sites eventually recovered from disturbances, the time needed to recover varied from 5 to 10 years depending on the disturbance dynamics. In addition to enhancing the functionality of the ORCHIDEE model, the new bark beetle model represents a fundamental change in the way mortality is simulated, as it replaces a framework in which mortality is conceived as a continuous process by one in which mortality is represented by abrupt events. Changing the mortality framework provided new insights into carbon balance estimates, showing the risk of overestimating the short term sequestration potential under the commonly used continuous mortality framework.

Published
2023

31. Nitrate radicals suppress biogenic new particle formation from monoterpene oxidation

Author

Li, Dandan, primary, Huang, Wei, additional, Wang, Dongyu, additional, Wang, Mingyi, additional, Thornton, Joel, additional, Caudillo, Lucía, additional, Rörup, Birte, additional, Marten, Ruby, additional, Scholz, Wiebke, additional, Finkenzeller, Henning, additional, Marie, Guillaume, additional, Bell, David, additional, Brasseur, Zoé, additional, Curtius, Joachim, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Gong, Xianda, additional, Hansel, Armin, additional, He, Xu-cheng, additional, Hofbauer, Victoria, additional, Junninen, Heikki, additional, Krechmer, Jordan E., additional, Kurten, Andreas, additional, Lamkaddam, Houssni, additional, LEHTIPALO, Katrianne, additional, Lopez, Brandon, additional, Ma, Yingge, additional, Mahfouz, Naser, additional, Manninen, Hanna E., additional, Mentler, Bernhard, additional, Perrier, Sebastien, additional, Petäjä, Tuukka, additional, Pfeifer, Joschka, additional, Philippov, Maxim, additional, Schervish, Meredith, additional, Schobesberger, Siegfried, additional, Shen, Jiali, additional, Surdu, Mihnea, additional, Tomaz, Sophie, additional, Volkamer, Rainer, additional, Wang, Xinke, additional, Weber, Stefan, additional, Welti, André, additional, Worsnop, Douglas, additional, wu, yusheng, additional, Yan, Chao, additional, Zauner-Wieczorek, Marcel, additional, Kulmala, Markku, additional, Kirkby, Jasper, additional, Donahue, Neil, additional, George, Christian, additional, El-Haddad, Imad, additional, Bianchi, Federico, additional, and Riva, Matthieu, additional

Published
2023
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34. Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere

Author

He, Xu-Cheng, Simon, Mario, Iyer, Siddharth, Xie, Hong-Bin, Rörup, Birte, Shen, Jiali, Finkenzeller, Henning, Stolzenburg, Dominik, Zhang, Rongjie, Baccarini, Andrea, Tham, Yee Jun, Wang, Mingyi, Amanatidis, Stavros, Piedehierro, Ana A., Amorim, Antonio, Baalbaki, Rima, Brasseur, Zoé, Caudillo, Lucía, Chu, Biwu, Dada, Lubna, Duplissy, Jonathan, El Haddad, Imad, Flagan, Richard C., Granzin, Manuel, Hansel, Armin, Heinritzi, Martin, Hofbauer, Victoria, Jokinen, Tuija, Kemppainen, Deniz, Kong, Weimeng, Krechmer, Jordan, Kürten, Andreas, Lamkaddam, Houssni, Lopez, Brandon, Ma, Fangfang, Mahfouz, Naser G. A., Makhmutov, Vladimir, Manninen, Hanna E., Marie, Guillaume, Marten, Ruby, Massabò, Dario, Mauldin, Roy L., Mentler, Bernhard, Onnela, Antti, Petäjä, Tuukka, Pfeifer, Joschka, Philippov, Maxim, Ranjithkumar, Ananth, Rissanen, Matti P., Schobesberger, Siegfried, Scholz, Wiebke, Schulze, Benjamin, Surdu, Mihnea, Thakur, Roseline C., Tomé, António, Wagner, Andrea C., Wang, Dongyu, Wang, Yonghong, Weber, Stefan K., Welti, André, Winkler, Paul M., Zauner-Wieczorek, Marcel, Baltensperger, Urs, Curtius, Joachim, Kurtén, Theo, Worsnop, Douglas R., Volkamer, Rainer, Lehtipalo, Katrianne, Kirkby, Jasper, Donahue, Neil M., Sipilä, Mikko, Kulmala, Markku, He, Xu-Cheng, Simon, Mario, Iyer, Siddharth, Xie, Hong-Bin, Rörup, Birte, Shen, Jiali, Finkenzeller, Henning, Stolzenburg, Dominik, Zhang, Rongjie, Baccarini, Andrea, Tham, Yee Jun, Wang, Mingyi, Amanatidis, Stavros, Piedehierro, Ana A., Amorim, Antonio, Baalbaki, Rima, Brasseur, Zoé, Caudillo, Lucía, Chu, Biwu, Dada, Lubna, Duplissy, Jonathan, El Haddad, Imad, Flagan, Richard C., Granzin, Manuel, Hansel, Armin, Heinritzi, Martin, Hofbauer, Victoria, Jokinen, Tuija, Kemppainen, Deniz, Kong, Weimeng, Krechmer, Jordan, Kürten, Andreas, Lamkaddam, Houssni, Lopez, Brandon, Ma, Fangfang, Mahfouz, Naser G. A., Makhmutov, Vladimir, Manninen, Hanna E., Marie, Guillaume, Marten, Ruby, Massabò, Dario, Mauldin, Roy L., Mentler, Bernhard, Onnela, Antti, Petäjä, Tuukka, Pfeifer, Joschka, Philippov, Maxim, Ranjithkumar, Ananth, Rissanen, Matti P., Schobesberger, Siegfried, Scholz, Wiebke, Schulze, Benjamin, Surdu, Mihnea, Thakur, Roseline C., Tomé, António, Wagner, Andrea C., Wang, Dongyu, Wang, Yonghong, Weber, Stefan K., Welti, André, Winkler, Paul M., Zauner-Wieczorek, Marcel, Baltensperger, Urs, Curtius, Joachim, Kurtén, Theo, Worsnop, Douglas R., Volkamer, Rainer, Lehtipalo, Katrianne, Kirkby, Jasper, Donahue, Neil M., Sipilä, Mikko, and Kulmala, Markku

Abstract

The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H2SO4), stabilized by ammonia (NH3). However, in marine and polar regions, NH3 is generally low, and H2SO4 is frequently found together with iodine oxoacids [HIOx, i.e., iodic acid (HIO3) and iodous acid (HIO2)]. In experiments performed with the CERN CLOUD (Cosmics Leaving OUtdoor Droplets) chamber, we investigated the interplay of H2SO4 and HIOx during atmospheric particle nucleation. We found that HIOx greatly enhances H2SO4(-NH3) nucleation through two different interactions. First, HIO3 strongly binds with H2SO4 in charged clusters so they drive particle nucleation synergistically. Second, HIO2 substitutes for NH3, forming strongly bound H2SO4-HIO2 acid-base pairs in molecular clusters. Global observations imply that HIOx is enhancing H2SO4(-NH3) nucleation rates 10- to 10,000-fold in marine and polar regions.

Published
2023

35. Stratégie de recherche et de veille documentaire - Philosophie

Author

Aurore-Marie Guillaume

Subjects
bibliothèques, recherche documentaire, veille documentaire, philosophie, doctorat, documentation, bibliographie, flux RSS
Abstract

Objectifs de la formation • Elaborer une stratégie de recherche bibliographique à partir de son sujet de thèse• Organiser une veille bibliographique avec les flux RSS• Connaître et maîtriser les fonctionnalités avancées des outils de recherche• Savoir accéder aux ressources documentaires acquises par son établissement

Published
2023
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37. Temperature, humidity, and ionisation effect of iodine oxoacid nucleation

Author

Rörup, Birte, He, Xu-Cheng, Shen, Jiali, Baalbaki, Rima, Dada, Lubna, Sipilä, Mikko, Kirkby, Jasper, Kulmala, Markku, Amorim, Antonio, Baccarini, Andrea, Bell, David M., Caudillo-Plath, Lucía, Duplissy, Jonathan, Finkenzeller, Henning, Kürten, Andreas, Lamkaddam, Houssni, Lee, Chuan Ping, Makhmutov, Vladimir, Manninen, Hanna E., Marie, Guillaume, Marten, Ruby, Mentler, Bernhard, Onnela, Antti, Philippov, Maxim, Scholz, Carolin Wiebke, Simon, Mario, Stolzenburg, Dominik, Tham, Yee Jun, Tomé, António, Wagner, Andrea C., Wang, Mingyi, Wang, Dongyu, Wang, Yonghong, Weber, Stefan K., Zauner-Wieczorek, Marcel, Baltensperger, Urs, Curtius, Joachim, Donahue, Neil M., El Haddad, Imad, Flagan, Richard C., Hansel, Armin, Möhler, Ottmar, Petäjä, Tuukka, Volkamer, Rainer, Worsnop, Douglas, and Lehtipalo, Katrianne

Abstract

Iodine oxoacids are recognised for their significant contribution to the formation of new particles in marine and polar atmospheres. Nevertheless, to incorporate the iodine oxoacid nucleation mechanism into global simulations, it is essential to comprehend how this mechanism varies under various atmospheric conditions. In this study, we combined measurements from the CLOUD (Cosmic Leaving OUtdoor Droplets) chamber at CERN and simulations with a kinetic model to investigate the impact of temperature, ionisation, and humidity on iodine oxoacid nucleation. Our findings reveal that ion-induced particle formation rates remain largely unaffected by changes in temperature. However, neutral particle formation rates experience a significant increase when the temperature drops from +10 °C to −10 °C. Running the kinetic model with varying ionisation rates demonstrates that the particle formation rate only increases with a higher ionisation rate when the iodic acid concentration exceeds 1.5 × 107cm−3, a concentration rarely reached in pristine marine atmospheres. Consequently, our simulations suggest that, despite higher ionisation rates, the charged cluster nucleation pathway of iodic acid is unlikely to be enhanced in the upper troposphere by higher ionisation rates. Instead, the neutral nucleation channel is likely to be the dominant channel in that region. Notably, the iodine oxoacid nucleation mechanism remains unaffected by changes in relative humidity from 2% to 80%. However, under unrealistically dry conditions (below 0.008% RH at +10 °C), iodine oxides (I2O4and I2O5) significantly enhance formation rates. Therefore, we conclude that iodine oxoacid nucleation is the dominant nucleation mechanism for iodine nucleation in the marine and polar boundary layer atmosphere.

Published
2024
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38. Molecular Understanding of the Enhancement in Organic Aerosol Mass at High Relative Humidity

Author

Surdu, Mihnea, primary, Lamkaddam, Houssni, additional, Wang, Dongyu S., additional, Bell, David M., additional, Xiao, Mao, additional, Lee, Chuan Ping, additional, Li, Dandan, additional, Caudillo, Lucía, additional, Marie, Guillaume, additional, Scholz, Wiebke, additional, Wang, Mingyi, additional, Lopez, Brandon, additional, Piedehierro, Ana A., additional, Ataei, Farnoush, additional, Baalbaki, Rima, additional, Bertozzi, Barbara, additional, Bogert, Pia, additional, Brasseur, Zoé, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Finkenzeller, Henning, additional, He, Xu-Cheng, additional, Höhler, Kristina, additional, Korhonen, Kimmo, additional, Krechmer, Jordan E., additional, Lehtipalo, Katrianne, additional, Mahfouz, Naser G. A., additional, Manninen, Hanna E., additional, Marten, Ruby, additional, Massabò, Dario, additional, Mauldin, Roy, additional, Petäjä, Tuukka, additional, Pfeifer, Joschka, additional, Philippov, Maxim, additional, Rörup, Birte, additional, Simon, Mario, additional, Shen, Jiali, additional, Umo, Nsikanabasi Silas, additional, Vogel, Franziska, additional, Weber, Stefan K., additional, Zauner-Wieczorek, Marcel, additional, Volkamer, Rainer, additional, Saathoff, Harald, additional, Möhler, Ottmar, additional, Kirkby, Jasper, additional, Worsnop, Douglas R., additional, Kulmala, Markku, additional, Stratmann, Frank, additional, Hansel, Armin, additional, Curtius, Joachim, additional, Welti, André, additional, Riva, Matthieu, additional, Donahue, Neil M., additional, Baltensperger, Urs, additional, and El Haddad, Imad, additional

Published
2023
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41. The gas-phase formation mechanism of iodic acid as an atmospheric aerosol source

Author

Finkenzeller, Henning, primary, Iyer, Siddharth, additional, He, Xu-Cheng, additional, Simon, Mario, additional, Koenig, Theodore K., additional, Lee, Christopher F., additional, Valiev, Rashid, additional, Hofbauer, Victoria, additional, Amorim, Antonio, additional, Baalbaki, Rima, additional, Baccarini, Andrea, additional, Beck, Lisa, additional, Bell, David M., additional, Caudillo, Lucía, additional, Chen, Dexian, additional, Chiu, Randall, additional, Chu, Biwu, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Heinritzi, Martin, additional, Kemppainen, Deniz, additional, Kim, Changhyuk, additional, Krechmer, Jordan, additional, Kürten, Andreas, additional, Kvashnin, Alexandr, additional, Lamkaddam, Houssni, additional, Lee, Chuan Ping, additional, Lehtipalo, Katrianne, additional, Li, Zijun, additional, Makhmutov, Vladimir, additional, Manninen, Hanna E., additional, Marie, Guillaume, additional, Marten, Ruby, additional, Mauldin, Roy L., additional, Mentler, Bernhard, additional, Müller, Tatjana, additional, Petäjä, Tuukka, additional, Philippov, Maxim, additional, Ranjithkumar, Ananth, additional, Rörup, Birte, additional, Shen, Jiali, additional, Stolzenburg, Dominik, additional, Tauber, Christian, additional, Tham, Yee Jun, additional, Tomé, António, additional, Vazquez-Pufleau, Miguel, additional, Wagner, Andrea C., additional, Wang, Dongyu S., additional, Wang, Mingyi, additional, Wang, Yonghong, additional, Weber, Stefan K., additional, Nie, Wei, additional, Wu, Yusheng, additional, Xiao, Mao, additional, Ye, Qing, additional, Zauner-Wieczorek, Marcel, additional, Hansel, Armin, additional, Baltensperger, Urs, additional, Brioude, Jérome, additional, Curtius, Joachim, additional, Donahue, Neil M., additional, Haddad, Imad El, additional, Flagan, Richard C., additional, Kulmala, Markku, additional, Kirkby, Jasper, additional, Sipilä, Mikko, additional, Worsnop, Douglas R., additional, Kurten, Theo, additional, Rissanen, Matti, additional, and Volkamer, Rainer, additional

Published
2022
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42. High Gas-Phase Methanesulfonic Acid Production in the OH-Initiated Oxidation of Dimethyl Sulfide at Low Temperatures

Author

Shen, Jiali, primary, Scholz, Wiebke, additional, He, Xu-Cheng, additional, Zhou, Putian, additional, Marie, Guillaume, additional, Wang, Mingyi, additional, Marten, Ruby, additional, Surdu, Mihnea, additional, Rörup, Birte, additional, Baalbaki, Rima, additional, Amorim, Antonio, additional, Ataei, Farnoush, additional, Bell, David M., additional, Bertozzi, Barbara, additional, Brasseur, Zoé, additional, Caudillo, Lucía, additional, Chen, Dexian, additional, Chu, Biwu, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Finkenzeller, Henning, additional, Granzin, Manuel, additional, Guida, Roberto, additional, Heinritzi, Martin, additional, Hofbauer, Victoria, additional, Iyer, Siddharth, additional, Kemppainen, Deniz, additional, Kong, Weimeng, additional, Krechmer, Jordan E., additional, Kürten, Andreas, additional, Lamkaddam, Houssni, additional, Lee, Chuan Ping, additional, Lopez, Brandon, additional, Mahfouz, Naser G. A., additional, Manninen, Hanna E., additional, Massabò, Dario, additional, Mauldin, Roy L., additional, Mentler, Bernhard, additional, Müller, Tatjana, additional, Pfeifer, Joschka, additional, Philippov, Maxim, additional, Piedehierro, Ana A., additional, Roldin, Pontus, additional, Schobesberger, Siegfried, additional, Simon, Mario, additional, Stolzenburg, Dominik, additional, Tham, Yee Jun, additional, Tomé, António, additional, Umo, Nsikanabasi Silas, additional, Wang, Dongyu, additional, Wang, Yonghong, additional, Weber, Stefan K., additional, Welti, André, additional, Wollesen de Jonge, Robin, additional, Wu, Yusheng, additional, Zauner-Wieczorek, Marcel, additional, Zust, Felix, additional, Baltensperger, Urs, additional, Curtius, Joachim, additional, Flagan, Richard C., additional, Hansel, Armin, additional, Möhler, Ottmar, additional, Petäjä, Tuukka, additional, Volkamer, Rainer, additional, Kulmala, Markku, additional, Lehtipalo, Katrianne, additional, Rissanen, Matti, additional, Kirkby, Jasper, additional, El-Haddad, Imad, additional, Bianchi, Federico, additional, Sipilä, Mikko, additional, Donahue, Neil M., additional, and Worsnop, Douglas R., additional

Published
2022
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44. Ammonium CI-Orbitrap: a tool for characterizing the reactivity of oxygenated organic molecules.

Author

Dandan Li, Dongyu Wang, Caudillo, Lucia, Scholz, Wiebke, Mingyi Wang, Tomaz, Sophie, Marie, Guillaume, Surdu, Mihnea, Eccli, Elias, Xianda Gong, Gonzalez-Carracedo, Loic, Granzin, Manuel, Pfeifer, Joschka, Rörup, Birte, Schulze, Benjamin, Rantala, Pekka, Perrier, Sébastien, Hansel, Armin, Curtius, Joachim, and Kirkby, Jasper

Subjects
CHEMICAL ionization mass spectrometry, MASS spectrometry, TIME-of-flight mass spectrometers, MASS spectrometers, ATMOSPHERIC aerosols, PINENE, NUCLEAR research
Abstract

Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges in measuring organic vapors, uncertainties remain in the formation and fate of OOMs. The chemical ionization Orbitrap mass spectrometer (CI-Orbitrap) has recently been shown to be a powerful technique able to accurately identify gaseous organic compounds due to its great mass resolving power. Here we present the ammonium ion (NH4+) based CI-Orbitrap as a technique capable of measuring a wide range of gaseous OOMs. The performance of the CI-(NH4+)-Orbitrap was compared with that of state-of-the-art mass spectrometers, including a nitrate ion (NO3-) based CI coupled to an atmospheric pressure interfaced to long time-of-flight mass spectrometer (APi-LTOF), a new generation of proton transfer reaction-TOF mass spectrometer (PTR3-TOF), and an iodide (I-) based CI-TOF mass spectrometer equipped with a Filter Inlet for Gases and AEROsols (FIGAERO-CIMS). The instruments were deployed simultaneously in the Cosmic Leaving OUtdoors Droplets (CLOUD) chamber at the European Organization for Nuclear Research (CERN) during the CLOUD14 campaign in 2019. Products generated from α-pinene ozonolysis across multiple experimental conditions were simultaneously measured by the mass spectrometers. NH4+-Orbitrap was able to identify the widest range of OOMs (i.e., O = 2), from low oxidized species to highly oxygenated volatile organic compounds (HOM). Excellent agreements were found between the NH4+-Orbitrap and the NO3--LTOF for characterizing HOMs and with the PTR3- TOF for the less oxidized monomeric species. A semi-quantitative information was retrieved for OOMs measured by NH4+-Orbitrap using calibration factors derived from this side-by-side comparison. As other mass spectrometry techniques used during this campaign, the detection sensitivity of NH4+-Orbitrap to OOMs is greatly affected by relative humidity, which may be related to changes in ionization efficiency and/or multiphase chemistry. Overall, this study shows that NH4+ ion46 based chemistry associated with the high mass resolving power of the Orbitrap mass analyzer can measure almost all-inclusive compounds. As a result, it is now possible to cover the entire range of compounds, which can lead to a better understanding of the oxidation processes. [ABSTRACT FROM AUTHOR]

Published
2023
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46. An intercomparison study of four different techniques for measuring the chemical composition of nanoparticles

Author

Caudillo, Lucía, primary, Surdu, Mihnea, additional, Lopez, Brandon, additional, Wang, Mingyi, additional, Thoma, Markus, additional, Bräkling, Steffen, additional, Buchholz, Angela, additional, Simon, Mario, additional, Wagner, Andrea C., additional, Müller, Tatjana, additional, Granzin, Manuel, additional, Heinritzi, Martin, additional, Amorim, Antonio, additional, Bell, David M., additional, Brasseur, Zoé, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Finkenzeller, Henning, additional, He, Xu-Cheng, additional, Lamkaddam, Houssni, additional, Mahfouz, Naser G. A., additional, Makhmutov, Vladimir, additional, Manninen, Hanna E., additional, Marie, Guillaume, additional, Marten, Ruby, additional, Mauldin, Roy L., additional, Mentler, Bernhard, additional, Onnela, Antti, additional, Petäjä, Tuukka, additional, Pfeifer, Joschka, additional, Philippov, Maxim, additional, Piedehierro, Ana A., additional, Rörup, Birte, additional, Scholz, Wiebke, additional, Shen, Jiali, additional, Stolzenburg, Dominik, additional, Tauber, Christian, additional, Tian, Ping, additional, Tomé, António, additional, Umo, Nsikanabasi Silas, additional, Wang, Dongyu S., additional, Wang, Yonghong, additional, Weber, Stefan K., additional, Welti, André, additional, Zauner-Wieczorek, Marcel, additional, Baltensperger, Urs, additional, Flagan, Richard C., additional, Hansel, Armin, additional, Kirkby, Jasper, additional, Kulmala, Markku, additional, Lehtipalo, Katrianne, additional, Worsnop, Douglas R., additional, Haddad, Imad El, additional, Donahue, Neil M., additional, Vogel, Alexander L., additional, Kürten, Andreas, additional, and Curtius, Joachim, additional

Published
2022
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47. Supplementary material to "An intercomparison study of four different techniques for measuring the chemical composition of nanoparticles"

Author

Caudillo, Lucía, primary, Surdu, Mihnea, additional, Lopez, Brandon, additional, Wang, Mingyi, additional, Thoma, Markus, additional, Bräkling, Steffen, additional, Buchholz, Angela, additional, Simon, Mario, additional, Wagner, Andrea C., additional, Müller, Tatjana, additional, Granzin, Manuel, additional, Heinritzi, Martin, additional, Amorim, Antonio, additional, Bell, David M., additional, Brasseur, Zoé, additional, Dada, Lubna, additional, Duplissy, Jonathan, additional, Finkenzeller, Henning, additional, He, Xu-Cheng, additional, Lamkaddam, Houssni, additional, Mahfouz, Naser G. A., additional, Makhmutov, Vladimir, additional, Manninen, Hanna E., additional, Marie, Guillaume, additional, Marten, Ruby, additional, Mauldin, Roy L., additional, Mentler, Bernhard, additional, Onnela, Antti, additional, Petäjä, Tuukka, additional, Pfeifer, Joschka, additional, Philippov, Maxim, additional, Piedehierro, Ana A., additional, Rörup, Birte, additional, Scholz, Wiebke, additional, Shen, Jiali, additional, Stolzenburg, Dominik, additional, Tauber, Christian, additional, Tian, Ping, additional, Tomé, António, additional, Umo, Nsikanabasi Silas, additional, Wang, Dongyu S., additional, Wang, Yonghong, additional, Weber, Stefan K., additional, Welti, André, additional, Zauner-Wieczorek, Marcel, additional, Baltensperger, Urs, additional, Flagan, Richard C., additional, Hansel, Armin, additional, Kirkby, Jasper, additional, Kulmala, Markku, additional, Lehtipalo, Katrianne, additional, Worsnop, Douglas R., additional, Haddad, Imad El, additional, Donahue, Neil M., additional, Vogel, Alexander L., additional, Kürten, Andreas, additional, and Curtius, Joachim, additional

Published
2022
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49. Estimating forest vulnerability to the next spruce budworm outbreak: will past silvicultural efforts pay dividends?

Author

Sainte-Marie, Guillaume B., Kneeshaw, Daniel D., MacLean, David A., and Hennigar, Chris R.

Subjects
Spruce -- Environmental aspects -- Economic aspects, Forest dynamics -- Economic aspects, Forest productivity -- Economic aspects, Dividends -- Environmental aspects, Company dividends, Earth sciences
Abstract

Silvicultural treatments recommended to reduce damage by spruce budworm (SBW; Choristoneurafumiferana Clemens) include reducing balsam fir (Abies balsamea (L.) Mill.) abundance and age and increasing spruce (Picea spp.) and hardwood content. To evaluate the effect of these measures on forest timber supply, we assessed stand characteristics, disturbance history, and timber supply for an intensively managed eastern Quebec forest from 1985 to 2004, encompassing a major SBW outbreak. During this time, mean stand age declined from 55 to 51 years, and proportions of areas in balsam fir stands declined (42% to 27%), spruce-fir stabilized (12% to 11%), and mixedwoods increased (32% to 52%). We estimated forest vulnerability using softwood volume reductions following simulated outbreak scenarios of different severity (low, moderate, and high) and different effects of hardwood content in reducing spruce-fir defoliation. Volume reductions for outbreaks simulated to begin in either 1985 or 2004 were similar, ranging from 15%-46% (no hardwood effect in reducing defoliation) to 13%-39% (given a maximum hardwood content effect) for light and severe outbreaks, respectively. Considering the net detrimental effect of increased hardwood content on softwood timber supply, we question the dividends of promoting hardwoods and recommend increasing the combined use of plantations and weeding treatments to increase spruce content. Key words: spruce budworm outbreak, silviculture, protective effects of hardwoods, softwood timber supply, forest protection. Les traitements sylvicoles recommandes pour reduire les dommages lors d'epidemies de la tordeuse des bourgeons de l'epinette (TBE; Choristoneurafumiferana Clemens) incluent la reduction de l'abondance et de l'age du sapin (Abies balsamea (L.) Mill.) et l'augmentation de l'abondance d'epinettes (Picea spp.) et de feuillus. Afin d'evaluer l'effet de ces mesures sur l'approvisionnement en bois, nous avons evalue de 1985 a 2004 les caracteristiques, l'historique des perturbations et l'approvisionnement en resineux d'une foret de l'est du Quebec sous amenagement intensif et pendant une epidemie majeure de TBE. Pendant cette periode, l'age moyen des peuplements a chute de 55 a 51 ans, la proportion de peuplements de sapin a chute (42 % a 27 %), celle d'epinette-sapin s'est maintenue (12 %a 11 %) et celle mixte a augmente (32 % a 52 %). La vulnerabilite des forets a ete estime a partir des reductions de volume resineux suivant des simulations d'epidemies de differentes severite (faible, moderee et severe) et effet des feuillus sur la reduction de la defoliation des hotes. Les pertes de bois des epidemies debutant en 1985 ou 2004 se sont averees similaires et s'elevaient de 15 %-46 % (aucun effet des feuillus) a 13 %-39 % (effet des feuillus maximal) pour les epidemies legeres et severes. Etant donne la difficulte d'augmenter l'abondance d'epinettes et les pertes nettes de production resineuse liees au contenu eleve en feuillus, nous remettons en question les benefices lies a la preservation des feuillus et recommandons une utilisation accrue du controle de la vegetation en plantation pour augmenter l'abondance d'epinette. Mots-cles : epidemie de tordeuse des bourgeons de l'epinette, sylviculture, effet de protection des feuillus, approvisionnement en bois resineux, protection des forets., Introduction The last spruce budworm (Choristoneura fumiferana Clemens; SBW) outbreak, which occurred from 1967 to 1992 in eastern Canada and in the United States (US), generated an estimated annual loss [...]

Published
2015
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