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51. Sexual Dichromatism Drives Diversification within a Major Radiation of African Amphibians

Author

Portik, Daniel M, Bell, Rayna C, Blackburn, David C, Bauer, Aaron M, Barratt, Christopher D, Branch, William R, Burger, Marius, Channing, Alan, Colston, Timothy J, Conradie, Werner, Dehling, J Maximilian, Drewes, Robert C, Ernst, Raffael, Greenbaum, Eli, Gvoždík, Václav, Harvey, James, Hillers, Annika, Hirschfeld, Mareike, Jongsma, Gregory FM, Kielgast, Jos, Kouete, Marcel T, Lawson, Lucinda P, Leaché, Adam D, Loader, Simon P, Lötters, Stefan, Van Der Meijden, Arie, Menegon, Michele, Müller, Susanne, Nagy, Zoltán T, Ofori-Boateng, Caleb, Ohler, Annemarie, Papenfuss, Theodore J, Rößler, Daniela, Sinsch, Ulrich, Rödel, Mark-Oliver, Veith, Michael, Vindum, Jens, Zassi-Boulou, Ange-Ghislain, and McGuire, Jimmy A

Subjects
Zoology, Evolutionary Biology, Biological Sciences, Infectious Diseases, Africa, Animals, Anura, Biological Evolution, Female, Male, Phylogeny, Pigmentation, Sex Characteristics, Afrobatrachia, color evolution, diversification, macroevolution, sexual selection, Genetics, Ecology, Evolutionary biology
Abstract

Theory predicts that sexually dimorphic traits under strong sexual selection, particularly those involved with intersexual signaling, can accelerate speciation and produce bursts of diversification. Sexual dichromatism (sexual dimorphism in color) is widely used as a proxy for sexual selection and is associated with rapid diversification in several animal groups, yet studies using phylogenetic comparative methods to explicitly test for an association between sexual dichromatism and diversification have produced conflicting results. Sexual dichromatism is rare in frogs, but it is both striking and prevalent in African reed frogs, a major component of the diverse frog radiation termed Afrobatrachia. In contrast to most other vertebrates, reed frogs display female-biased dichromatism in which females undergo color transformation, often resulting in more ornate coloration in females than in males. We produce a robust phylogeny of Afrobatrachia to investigate the evolutionary origins of sexual dichromatism in this radiation and examine whether the presence of dichromatism is associated with increased rates of net diversification. We find that sexual dichromatism evolved once within hyperoliids and was followed by numerous independent reversals to monochromatism. We detect significant diversification rate heterogeneity in Afrobatrachia and find that sexually dichromatic lineages have double the average net diversification rate of monochromatic lineages. By conducting trait simulations on our empirical phylogeny, we demonstrate that our inference of trait-dependent diversification is robust. Although sexual dichromatism in hyperoliid frogs is linked to their rapid diversification and supports macroevolutionary predictions of speciation by sexual selection, the function of dichromatism in reed frogs remains unclear. We propose that reed frogs are a compelling system for studying the roles of natural and sexual selection on the evolution of sexual dichromatism across micro- and macroevolutionary timescales.

Published
2019

53. Understanding Natural Disaster or Weather-Related Drowning Deaths Among Children.

Author

Hillers, Gabrielle M., Joy, Susanna C., Chatham-Stephens, Kevin, Collier, Abigael, Gentry, Brittany, Bélanger-Giguère, Kim, and Clemens, Tessa

Subjects
*DROWNING, *RISK assessment, *RESEARCH funding, *DEATH, *DESCRIPTIVE statistics, *CHI-squared test, *AGE distribution, *POPULATION geography, *WEATHER, *NATURAL disasters, *CHILDREN
Abstract

OBJECTIVES: Drowning is the leading cause of death during flood disasters. Little is known about these deaths. Child death review teams review details of child deaths to understand circumstances and risk factors to inform prevention. METHODS: Using data entered in 2005 to 2021 for children ages 0 to 17 years from the National Fatality Review-Case Reporting System, we identified 130 drowning deaths directly attributed to natural disaster or weather incidents, and 14 deaths indirectly attributed to these incidents. Frequencies, proportions, and χ² statistics were used to describe selected measures and compare with other drowning deaths. RESULTS: Children who drowned as a direct result of a natural disaster- or weather-related incident were more likely to be aged >4 years (81% vs 40%, P < .001) and located in a rural or frontier setting (63% vs 30%, P < .001). They were more likely to be supervised at the time of the incident (61% vs 38%, P < .001), and it was more likely for additional children (35% vs 5%, P < .001) or adults (33% vs 3%, P < .001) to have perished. The indirect deaths were commonly a result of damage to protective barriers. CONCLUSIONS: The characteristics of natural disaster- or weather-related drowning deaths among children differ from other drowning deaths. Natural disaster- or weather-related drowning may warrant tailored drowning prevention strategies. Improved surveillance of all water-related deaths may be a proactive action leading to the development of these prevention strategies, whereas poststorm remediation of protective barriers can be used as a reactive prevention after a storm has passed. [ABSTRACT FROM AUTHOR]

Published
2024
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54. A new slippery frog (Amphibia, Conrauidae, Conraua Nieden, 1908) from the Fouta Djallon Highlands, west-central Guinea

Author

Karla Neira-Salamea, Joseph Doumbia, Annika Hillers, Laura Sandberger-Loua, N’Goran G. Kouamé, Christian Brede, Marvin Schäfer, David C. Blackburn, Michael F. Barej, and Mark-Oliver Rödel

Subjects
Biology (General), QH301-705.5
Abstract

We describe a new species of the genus Conraua from the Fouta Djallon Highlands in Guinea. The species is recognised as distinct from nominotypical C. alleni, based on morphological evidence and is supported by a recent species delimitation analysis, based on DNA sequence data. The new species is distinguished from its congeners by the unique combination of the following characters: medium body size, robust limbs, only one instead of two palmar tubercles, the first finger webbed to below the first subarticular tubercle, presence of a lateral line system, indistinct tympanum, two subarticular tubercles on fingers III and IV, venter in adults white with dark brown spots or dark brown with grey or whitish spots. The new species differs from all congeners by more than 6% in the DNA sequence of mitochondrial ribosomal 16S. We discuss isolation in Pliocene and Pleistocene forest refugia as a potential driver of speciation in the C. alleni complex. We also emphasise the importance of conserving the remaining forest fragments in the Fouta Djallon Region for the preservation of both its unique biodiversity and its valuable water sources for local people.

Published
2022
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57. Pyrene Functionalized Norbornadiene‐Quadricyclane Fluorescent Photoswitches: Characterization of their Spectral Properties and Application in Imaging of Amyloid Beta Plaques

Author

Ghasemi, Shima, primary, Shamsabadi, Monika, additional, Olesund, Axel, additional, Hillers-Bendtsen, Andreas Erbs, additional, Najera, Francisco, additional, Edhborg, Fredrik, additional, Aslam, Adil S., additional, Larsson, Wera, additional, Wang, Zhihang, additional, Amombo Noa, Francoise M., additional, Salthouse, Rebecca J., additional, Öhrström, Lars, additional, Hölzel, Helen, additional, Perez-Inestrosa, Ezequiel, additional, Mikkelsen, Kurt V., additional, Hanrieder, Jörg, additional, Albinsson, Bo, additional, Dreos, Ambra, additional, and Moth-Poulsen, Kasper, additional

Published
2024
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58. Efectos de la pandemia de la COVID-19 en la salud mental de pacientes con psicopatología previa

Author

Hillers Rodríguez, Rosalía, San Vicente Cano, Adela, Portabales Barreiro, Laura, Madoz Gúrpide, Agustín, Hillers Rodríguez, Rosalía, San Vicente Cano, Adela, Portabales Barreiro, Laura, and Madoz Gúrpide, Agustín

Abstract

FUNDAMENTOS // Numerosos estudios han confirmado que las personas con un diagnóstico psiquiátrico se vieron más afectadas en su salud mental que la población general en una primera fase de la pandemia de la COVID-19. El objetivo de este trabajo fue estudiar los efectos de la pandemia, más de un año después de su inicio, en el estado psíquico de pacientes adultos con psicopatología previa de un Centro de Salud Mental (CSM) en Madrid. MÉTODOS // Se realizó un estudio observacional transversal en una muestra de cincuenta y ocho pacientes mediante un cuestionario que recogía diferentes variables descriptivas. Se administraron la Escala de Depresión PHQ-9, la Escala de Ansiedad GAD-7, la Escala Revisada de Impacto del Estresor EIE-R, la Escala de Impresión Clínica Global CGI-GI y la valoración de los facultativos responsables de los pacientes sobre el estado clínico de los pacientes. Se realizó un análisis descriptivo y se aplicaron modelos de regresión logística binaria. RESULTADOS // Hubo una prevalencia de 70% de ansiedad, 76% de depresión y 57% de estrés por evento estresante más de un año después de iniciarse la pandemia. Asimismo, se encontró asociación de los síntomas clínicos con determinadas variables clínicas, con variables mediadoras y con el género. CONCLUSIONES // El estado psíquico de los pacientes con psicopatología previa atendidos en el CSM se ve negativamente afectado por la pandemia de la COVID-19 hasta año y medio después de su inicio.

Published
2024

59. Positive feedbacks and alternative stable states in forest leaf types

Author

Zou, Yibiao, Zohner, Constantin M., Averill, Colin, Ma, Haozhi, Merder, Julian, Berdugo, Miguel, Bialic-Murphy, Lalasia, Mo, Lidong, Brun, Philipp, Zimmermann, Niklaus E., Liang, Jingjing, de-Miguel, Sergio, Nabuurs, Gert Jan, Reich, Peter B., Niinements, Ulo, Dahlgren, Jonas, Kändler, Gerald, Ratcliffe, Sophia, Ruiz-Benito, Paloma, de Zavala, Miguel Angel, Crowther, Thomas W., Abegg, Meinrad, Adou Yao, Yves C., Alberti, Giorgio, Almeyda Zambrano, Angelica M., Alvarado, Braulio Vilchez, Alvarez-Dávila, Esteban, Alvarez-Loayza, Patricia, Alves, Luciana F., Ammer, Christian, Antón-Fernández, Clara, Araujo-Murakami, Alejandro, Arroyo, Luzmila, Avitabile, Valerio, Aymard, Gerardo A., Baker, Timothy R., Bałazy, Radomir, Banki, Olaf, Barroso, Jorcely G., Bastian, Meredith L., Bastin, Jean Francois, Birigazzi, Luca, Birnbaum, Philippe, Bitariho, Robert, Boeckx, Pascal, Bongers, Frans, Bouriaud, Olivier, Brancalion, Pedro H.S., Brandl, Susanne, Brearley, Francis Q., Brienen, Roel, Broadbent, Eben N., Bruelheide, Helge, Bussotti, Filippo, Gatti, Roberto Cazzolla, César, Ricardo G., Cesljar, Goran, Chazdon, Robin, Chen, Han Y.H., Chisholm, Chelsea, Cho, Hyunkook, Cienciala, Emil, Clark, Connie, Clark, David, Colletta, Gabriel D., Coomes, David A., Valverde, Fernando Cornejo, Corral-Rivas, José J., Crim, Philip M., Cumming, Jonathan R., Dayanandan, Selvadurai, de Gasper, André L., Decuyper, Mathieu, Derroire, Géraldine, DeVries, Ben, Djordjevic, Ilija, Dolezal, Jiri, Dourdain, Aurélie, Obiang, Nestor Laurier Engone, Enquist, Brian J., Eyre, Teresa J., Fandohan, Adandé Belarmain, Fayle, Tom M., Feldpausch, Ted R., Ferreira, Leandro V., Finér, Leena, Fischer, Markus, Fletcher, Christine, Fridman, Jonas, Frizzera, Lorenzo, Gamarra, Javier G.P., Gianelle, Damiano, Glick, Henry B., Harris, David J., Hector, Andrew, Hemp, Andreas, Hengeveld, Geerten, Hérault, Bruno, Herbohn, John L., Herold, Martin, Hillers, Annika, Honorio Coronado, Eurídice N., Hui, Cang, Ibanez, Thomas, Iêda, Amaral, Imai, Nobuo, Jagodziński, Andrzej M., Jaroszewicz, Bogdan, Johannsen, Vivian Kvist, Joly, Carlos A., Jucker, Tommaso, Jung, Ilbin, Karminov, Viktor, Kartawinata, Kuswata, Kearsley, Elizabeth, Kenfack, David, Kennard, Deborah K., Kepfer-Rojas, Sebastian, Keppel, Gunnar, Khan, Mohammed Latif, Killeen, Timothy J., Kim, Hyun Seok, Kitayama, Kanehiro, Köhl, Michael, Korjus, Henn, Kraxner, Florian, Laarmann, Diana, Lang, Mait, Lewis, Simon L., Lu, Huicui, Lukina, Natalia V., Maitner, Brian S., Malhi, Yadvinder, Marcon, Eric, Marimon, Beatriz Schwantes, Marimon-Junior, Ben Hur, Marshall, Andrew R., Martin, Emanuel H., Kucher, Dmitry, Meave, Jorge A., Melo-Cruz, Omar, Mendoza, Casimiro, Merow, Cory, Mendoza, Abel Monteagudo, Moreno, Vanessa S., Mukul, Sharif A., Mundhenk, Philip, Nava-Miranda, María Guadalupe, Neill, David, Neldner, Victor J., Nevenic, Radovan V., Ngugi, Michael R., Niklaus, Pascal A., Oleksyn, Jacek, Ontikov, Petr, Ortiz-Malavasi, Edgar, Pan, Yude, Paquette, Alain, Parada-Gutierrez, Alexander, Parfenova, Elena I., Park, Minjee, Parren, Marc, Parthasarathy, Narayanaswamy, Peri, Pablo L., Pfautsch, Sebastian, Phillips, Oliver L., Picard, Nicolas, Piedade, Maria Teresa T.F., Piotto, Daniel, Pitman, Nigel C.A., Polo, Irina, Poorter, Lourens, Poulsen, Axel D., Poulsen, John R., Pretzsch, Hans, Arevalo, Freddy Ramirez, Restrepo-Correa, Zorayda, Rodeghiero, Mirco, Rolim, Samir G., Roopsind, Anand, Rovero, Francesco, Rutishauser, Ervan, Saikia, Purabi, Salas-Eljatib, Christian, Saner, Philippe, Schall, Peter, Schelhaas, Mart Jan, Schepaschenko, Dmitry, Scherer-Lorenzen, Michael, Schmid, Bernhard, Schöngart, Jochen, Searle, Eric B., Seben, Vladimír, Serra-Diaz, Josep M., Sheil, Douglas, Shvidenko, Anatoly Z., Silva-Espejo, Javier E., Silveira, Marcos, Singh, James, Sist, Plinio, Slik, Ferry, Sonké, Bonaventure, Souza, Alexandre F., Miscicki, Stanislaw, Stereńczak, Krzysztof J., Svenning, Jens Christian, Svoboda, Miroslav, Swanepoel, Ben, Targhetta, Natalia, Tchebakova, Nadja, ter Steege, Hans, Thomas, Raquel, Tikhonova, Elena, Umunay, Peter M., Usoltsev, Vladimir A., Valencia, Renato, Valladares, Fernando, van der Plas, Fons, Van Do, Tran, van Nuland, Michael E., Vasquez, Rodolfo M., Verbeeck, Hans, Viana, Helder, Vibrans, Alexander C., Vieira, Simone, von Gadow, Klaus, Wang, Hua Feng, Watson, James V., Werner, Gijsbert D.A., Westerlund, Bertil, Wiser, Susan K., Wittmann, Florian, Woell, Hannsjoerg, Wortel, Verginia, Zagt, Roderik, Zawiła-Niedźwiecki, Tomasz, Zhang, Chunyu, Zhao, Xiuhai, Zhou, Mo, Zhu, Zhi Xin, Zo-Bi, Irie C., Zou, Yibiao, Zohner, Constantin M., Averill, Colin, Ma, Haozhi, Merder, Julian, Berdugo, Miguel, Bialic-Murphy, Lalasia, Mo, Lidong, Brun, Philipp, Zimmermann, Niklaus E., Liang, Jingjing, de-Miguel, Sergio, Nabuurs, Gert Jan, Reich, Peter B., Niinements, Ulo, Dahlgren, Jonas, Kändler, Gerald, Ratcliffe, Sophia, Ruiz-Benito, Paloma, de Zavala, Miguel Angel, Crowther, Thomas W., Abegg, Meinrad, Adou Yao, Yves C., Alberti, Giorgio, Almeyda Zambrano, Angelica M., Alvarado, Braulio Vilchez, Alvarez-Dávila, Esteban, Alvarez-Loayza, Patricia, Alves, Luciana F., Ammer, Christian, Antón-Fernández, Clara, Araujo-Murakami, Alejandro, Arroyo, Luzmila, Avitabile, Valerio, Aymard, Gerardo A., Baker, Timothy R., Bałazy, Radomir, Banki, Olaf, Barroso, Jorcely G., Bastian, Meredith L., Bastin, Jean Francois, Birigazzi, Luca, Birnbaum, Philippe, Bitariho, Robert, Boeckx, Pascal, Bongers, Frans, Bouriaud, Olivier, Brancalion, Pedro H.S., Brandl, Susanne, Brearley, Francis Q., Brienen, Roel, Broadbent, Eben N., Bruelheide, Helge, Bussotti, Filippo, Gatti, Roberto Cazzolla, César, Ricardo G., Cesljar, Goran, Chazdon, Robin, Chen, Han Y.H., Chisholm, Chelsea, Cho, Hyunkook, Cienciala, Emil, Clark, Connie, Clark, David, Colletta, Gabriel D., Coomes, David A., Valverde, Fernando Cornejo, Corral-Rivas, José J., Crim, Philip M., Cumming, Jonathan R., Dayanandan, Selvadurai, de Gasper, André L., Decuyper, Mathieu, Derroire, Géraldine, DeVries, Ben, Djordjevic, Ilija, Dolezal, Jiri, Dourdain, Aurélie, Obiang, Nestor Laurier Engone, Enquist, Brian J., Eyre, Teresa J., Fandohan, Adandé Belarmain, Fayle, Tom M., Feldpausch, Ted R., Ferreira, Leandro V., Finér, Leena, Fischer, Markus, Fletcher, Christine, Fridman, Jonas, Frizzera, Lorenzo, Gamarra, Javier G.P., Gianelle, Damiano, Glick, Henry B., Harris, David J., Hector, Andrew, Hemp, Andreas, Hengeveld, Geerten, Hérault, Bruno, Herbohn, John L., Herold, Martin, Hillers, Annika, Honorio Coronado, Eurídice N., Hui, Cang, Ibanez, Thomas, Iêda, Amaral, Imai, Nobuo, Jagodziński, Andrzej M., Jaroszewicz, Bogdan, Johannsen, Vivian Kvist, Joly, Carlos A., Jucker, Tommaso, Jung, Ilbin, Karminov, Viktor, Kartawinata, Kuswata, Kearsley, Elizabeth, Kenfack, David, Kennard, Deborah K., Kepfer-Rojas, Sebastian, Keppel, Gunnar, Khan, Mohammed Latif, Killeen, Timothy J., Kim, Hyun Seok, Kitayama, Kanehiro, Köhl, Michael, Korjus, Henn, Kraxner, Florian, Laarmann, Diana, Lang, Mait, Lewis, Simon L., Lu, Huicui, Lukina, Natalia V., Maitner, Brian S., Malhi, Yadvinder, Marcon, Eric, Marimon, Beatriz Schwantes, Marimon-Junior, Ben Hur, Marshall, Andrew R., Martin, Emanuel H., Kucher, Dmitry, Meave, Jorge A., Melo-Cruz, Omar, Mendoza, Casimiro, Merow, Cory, Mendoza, Abel Monteagudo, Moreno, Vanessa S., Mukul, Sharif A., Mundhenk, Philip, Nava-Miranda, María Guadalupe, Neill, David, Neldner, Victor J., Nevenic, Radovan V., Ngugi, Michael R., Niklaus, Pascal A., Oleksyn, Jacek, Ontikov, Petr, Ortiz-Malavasi, Edgar, Pan, Yude, Paquette, Alain, Parada-Gutierrez, Alexander, Parfenova, Elena I., Park, Minjee, Parren, Marc, Parthasarathy, Narayanaswamy, Peri, Pablo L., Pfautsch, Sebastian, Phillips, Oliver L., Picard, Nicolas, Piedade, Maria Teresa T.F., Piotto, Daniel, Pitman, Nigel C.A., Polo, Irina, Poorter, Lourens, Poulsen, Axel D., Poulsen, John R., Pretzsch, Hans, Arevalo, Freddy Ramirez, Restrepo-Correa, Zorayda, Rodeghiero, Mirco, Rolim, Samir G., Roopsind, Anand, Rovero, Francesco, Rutishauser, Ervan, Saikia, Purabi, Salas-Eljatib, Christian, Saner, Philippe, Schall, Peter, Schelhaas, Mart Jan, Schepaschenko, Dmitry, Scherer-Lorenzen, Michael, Schmid, Bernhard, Schöngart, Jochen, Searle, Eric B., Seben, Vladimír, Serra-Diaz, Josep M., Sheil, Douglas, Shvidenko, Anatoly Z., Silva-Espejo, Javier E., Silveira, Marcos, Singh, James, Sist, Plinio, Slik, Ferry, Sonké, Bonaventure, Souza, Alexandre F., Miscicki, Stanislaw, Stereńczak, Krzysztof J., Svenning, Jens Christian, Svoboda, Miroslav, Swanepoel, Ben, Targhetta, Natalia, Tchebakova, Nadja, ter Steege, Hans, Thomas, Raquel, Tikhonova, Elena, Umunay, Peter M., Usoltsev, Vladimir A., Valencia, Renato, Valladares, Fernando, van der Plas, Fons, Van Do, Tran, van Nuland, Michael E., Vasquez, Rodolfo M., Verbeeck, Hans, Viana, Helder, Vibrans, Alexander C., Vieira, Simone, von Gadow, Klaus, Wang, Hua Feng, Watson, James V., Werner, Gijsbert D.A., Westerlund, Bertil, Wiser, Susan K., Wittmann, Florian, Woell, Hannsjoerg, Wortel, Verginia, Zagt, Roderik, Zawiła-Niedźwiecki, Tomasz, Zhang, Chunyu, Zhao, Xiuhai, Zhou, Mo, Zhu, Zhi Xin, and Zo-Bi, Irie C.

Abstract

The emergence of alternative stable states in forest systems has significant implications for the functioning and structure of the terrestrial biosphere, yet empirical evidence remains scarce. Here, we combine global forest biodiversity observations and simulations to test for alternative stable states in the presence of evergreen and deciduous forest types. We reveal a bimodal distribution of forest leaf types across temperate regions of the Northern Hemisphere that cannot be explained by the environment alone, suggesting signatures of alternative forest states. Moreover, we empirically demonstrate the existence of positive feedbacks in tree growth, recruitment and mortality, with trees having 4–43% higher growth rates, 14–17% higher survival rates and 4–7 times higher recruitment rates when they are surrounded by trees of their own leaf type. Simulations show that the observed positive feedbacks are necessary and sufficient to generate alternative forest states, which also lead to dependency on history (hysteresis) during ecosystem transition from evergreen to deciduous forests and vice versa. We identify hotspots of bistable forest types in evergreen-deciduous ecotones, which are likely driven by soil-related positive feedbacks. These findings are integral to predicting the distribution of forest biomes, and aid to our understanding of biodiversity, carbon turnover, and terrestrial climate feedbacks.

Published
2024

60. Dominance and rarity in tree communities across the globe: Patterns, predictors and threats

Author

Hordijk, I., Bialic‐Murphy, L., Lauber, T., Routh, D., Poorter, L., Rivers, M., ter Steege, H., Liang, J., Reich, P., de‐Miguel, S., Nabuurs, G.-J., Gamarra, J., Chen, H., Zhou, M., Wiser, S., Pretzsch, H., Paquette, A., Picard, N., Hérault, B., Bastin, J.-F., Alberti, G., Abegg, M., Adou Yao, Y., Almeyda Zambrano, A., Alvarado, B., Alvarez‐Davila, E., Alvarez‐Loayza, P., Alves, L., Ammer, C., Antón‐Fernández, C., Araujo‐Murakami, A., Arroyo, L., Avitabile, V., Aymard Corredor, G., Baker, T., Banki, O., Barroso, J., Bastian, M., Birigazzi, L., Birnbaum, P., Bitariho, R., Boeckx, P., Bongers, F., Bouriaud, O., Brancalion, P., Brandl, S., Brienen, R., Broadbent, E., Bruelheide, H., Bussotti, F., Gatti, R., Cesar, R., Cesljar, G., Chazdon, R., Chisholm, C., Cienciala, E., Clark, C., Clar, D., Colletta, G., Coomes, D., Valverde, F., Corral‐Rivas, J., Crim, P., Cumming, J., Dayanandan, S., de Gasper, A., Decuyper, M., Derroire, G., DeVries, B., Djordjevic, I., Iêda, A., Dourdain, A., Dolezal, J., Obiang, N., Enquist, B., Eyre, T., Fandohan, A., Fayle, T., Ferreira, L., Feldpausch, T., Finér, L., Fischer, M., Fletcher, C., Frizzera, L., Gianelle, D., Glick, H., Harris, D., Hector, A., Hemp, A., Hengeveld, G., Herbohn, J., Hillers, A., Honorio Coronado, E., Hui, C., Cho, H., Ibanez, T., Jung, I., Imai, N., Jagodzinski, A., Jaroszewicz, B., Johannsen, V., Joly, C., Jucker, T., Karminov, V., Kartawinata, K., Kearsley, E., Kenfack, D., Kennard, D., Kepfer‐Rojas, S., Keppel, G., Khan, M., Killeen, T., Kim, H., Kitayama, K., Köhl, M., Korjus, H., Kraxner, F., Laarmann, D., Lang, M., Lewis, S., Lu, H., Lukina, N., Maitner, B., Malhi, Y., Marcon, E., Marimon, B., Marimon‐Junior, B., Marshall, A., Martin, E., Martynenko, O., Meave, J., Melo‐Cruz, O., Mendoza, C., Merow, C., Miscicki, S., Mendoza, A., Moreno, V., Mukul, S., Mundhenk, P., Nava‐Miranda, M., Neill, D., Neldner, V., Nevenic, R., Ngugi, M., Niklaus, P., Oleksyn, J., Ontikov, P., Ortiz‐Malavasi, E., Pan, Y., Parada‐Gutierrez, A., Parfenova, E., Park, M., Parren, M., Parthasarathy, N., Peri, P., Pfautsch, S., Phillips, O., Piedade, M., Piotto, D., Pitman, N., Polo, I., Poulsen, A., Poulsen, J., Arevalo, F., Restrepo‐Correa, Z., Rodeghiero, M., Rolim, S., Roopsind, A., Rovero, F., Rutishauser, E., Saikia, P., Salas‐Eljatib, C., Schall, P., Shchepashchenko, D., Scherer‐Lorenzen, M., Schmid, B., Schöngart, J., Searle, E., Seben, V., Serra‐Diaz, J., Sheil, D., Shvidenko, A., Silva‐Espejo, J., Silveira, M., Singh, J., Sist, P., Slik, F., Sonké, B., Souza, A., Stereńczak, K., Svenning, J.-C., Svoboda, M., Swanepoel, B., Targhetta, N., Tchebakova, N., Thomas, R., Tikhonova, E., Umunay, P., Usoltsev, V., Valencia, R., Valladares, F., van der Plas, F., Van Do, T., Van Nuland, M., Martinez, R., Verbeeck, H., Viana, H., Vibrans, A., Vieira, S., von Gadow, K., Wang, H.-F., Watson, J., Werner, G., Wittmann, F., Wortel, V., Zagt, R., Zawila‐Niedzwiecki, T., Zhang, C., Zhao, X., Zhu, Z.-X., Zo‐Bi, I., Maynard, D., Crowther, T., Hordijk, I., Bialic‐Murphy, L., Lauber, T., Routh, D., Poorter, L., Rivers, M., ter Steege, H., Liang, J., Reich, P., de‐Miguel, S., Nabuurs, G.-J., Gamarra, J., Chen, H., Zhou, M., Wiser, S., Pretzsch, H., Paquette, A., Picard, N., Hérault, B., Bastin, J.-F., Alberti, G., Abegg, M., Adou Yao, Y., Almeyda Zambrano, A., Alvarado, B., Alvarez‐Davila, E., Alvarez‐Loayza, P., Alves, L., Ammer, C., Antón‐Fernández, C., Araujo‐Murakami, A., Arroyo, L., Avitabile, V., Aymard Corredor, G., Baker, T., Banki, O., Barroso, J., Bastian, M., Birigazzi, L., Birnbaum, P., Bitariho, R., Boeckx, P., Bongers, F., Bouriaud, O., Brancalion, P., Brandl, S., Brienen, R., Broadbent, E., Bruelheide, H., Bussotti, F., Gatti, R., Cesar, R., Cesljar, G., Chazdon, R., Chisholm, C., Cienciala, E., Clark, C., Clar, D., Colletta, G., Coomes, D., Valverde, F., Corral‐Rivas, J., Crim, P., Cumming, J., Dayanandan, S., de Gasper, A., Decuyper, M., Derroire, G., DeVries, B., Djordjevic, I., Iêda, A., Dourdain, A., Dolezal, J., Obiang, N., Enquist, B., Eyre, T., Fandohan, A., Fayle, T., Ferreira, L., Feldpausch, T., Finér, L., Fischer, M., Fletcher, C., Frizzera, L., Gianelle, D., Glick, H., Harris, D., Hector, A., Hemp, A., Hengeveld, G., Herbohn, J., Hillers, A., Honorio Coronado, E., Hui, C., Cho, H., Ibanez, T., Jung, I., Imai, N., Jagodzinski, A., Jaroszewicz, B., Johannsen, V., Joly, C., Jucker, T., Karminov, V., Kartawinata, K., Kearsley, E., Kenfack, D., Kennard, D., Kepfer‐Rojas, S., Keppel, G., Khan, M., Killeen, T., Kim, H., Kitayama, K., Köhl, M., Korjus, H., Kraxner, F., Laarmann, D., Lang, M., Lewis, S., Lu, H., Lukina, N., Maitner, B., Malhi, Y., Marcon, E., Marimon, B., Marimon‐Junior, B., Marshall, A., Martin, E., Martynenko, O., Meave, J., Melo‐Cruz, O., Mendoza, C., Merow, C., Miscicki, S., Mendoza, A., Moreno, V., Mukul, S., Mundhenk, P., Nava‐Miranda, M., Neill, D., Neldner, V., Nevenic, R., Ngugi, M., Niklaus, P., Oleksyn, J., Ontikov, P., Ortiz‐Malavasi, E., Pan, Y., Parada‐Gutierrez, A., Parfenova, E., Park, M., Parren, M., Parthasarathy, N., Peri, P., Pfautsch, S., Phillips, O., Piedade, M., Piotto, D., Pitman, N., Polo, I., Poulsen, A., Poulsen, J., Arevalo, F., Restrepo‐Correa, Z., Rodeghiero, M., Rolim, S., Roopsind, A., Rovero, F., Rutishauser, E., Saikia, P., Salas‐Eljatib, C., Schall, P., Shchepashchenko, D., Scherer‐Lorenzen, M., Schmid, B., Schöngart, J., Searle, E., Seben, V., Serra‐Diaz, J., Sheil, D., Shvidenko, A., Silva‐Espejo, J., Silveira, M., Singh, J., Sist, P., Slik, F., Sonké, B., Souza, A., Stereńczak, K., Svenning, J.-C., Svoboda, M., Swanepoel, B., Targhetta, N., Tchebakova, N., Thomas, R., Tikhonova, E., Umunay, P., Usoltsev, V., Valencia, R., Valladares, F., van der Plas, F., Van Do, T., Van Nuland, M., Martinez, R., Verbeeck, H., Viana, H., Vibrans, A., Vieira, S., von Gadow, K., Wang, H.-F., Watson, J., Werner, G., Wittmann, F., Wortel, V., Zagt, R., Zawila‐Niedzwiecki, T., Zhang, C., Zhao, X., Zhu, Z.-X., Zo‐Bi, I., Maynard, D., and Crowther, T.

Abstract

Aim Ecological and anthropogenic factors shift the abundances of dominant and rare tree species within local forest communities, thus affecting species composition and ecosystem functioning. To inform forest and conservation management it is important to understand the drivers of dominance and rarity in local tree communities. We answer the following research questions: (1) What are the patterns of dominance and rarity in tree communities? (2) Which ecological and anthropogenic factors predict these patterns? And (3) what is the extinction risk of locally dominant and rare tree species? Location Global. Time period 1990–2017. Major taxa studied Trees. Methods We used 1.2 million forest plots and quantified local tree dominance as the relative plot basal area of the single most dominant species and local rarity as the percentage of species that contribute together to the least 10% of plot basal area. We mapped global community dominance and rarity using machine learning models and evaluated the ecological and anthropogenic predictors with linear models. Extinction risk, for example threatened status, of geographically widespread dominant and rare species was evaluated. Results Community dominance and rarity show contrasting latitudinal trends, with boreal forests having high levels of dominance and tropical forests having high levels of rarity. Increasing annual precipitation reduces community dominance, probably because precipitation is related to an increase in tree density and richness. Additionally, stand age is positively related to community dominance, due to stem diameter increase of the most dominant species. Surprisingly, we find that locally dominant and rare species, which are geographically widespread in our data, have an equally high rate of elevated extinction due to declining populations through large-scale land degradation. Main conclusions By linking patterns and predictors of community dominance and rarity to extinction risk, our results suggest tha

Published
2024
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61. Dynamical Effects of Solvation on Norbornadiene/Quadricyclane Systems

Author

Hillers-Bendtsen, Andreas Erbs, Todarwal, Yogesh, Norman, Patrick, Mikkelsen, Kurt V., Hillers-Bendtsen, Andreas Erbs, Todarwal, Yogesh, Norman, Patrick, and Mikkelsen, Kurt V.

Abstract

Molecules that can undergo reversible chemical transformations following the absorption of light, the so-called molecular photoswitches, have attracted increasing attention in technologies, such as solar energy storage. Here, the optical and thermochemical properties of the photoswitch are central to its applicability, and these properties are influenced significantly by solvation. We investigate the effects of solvation on two norbornadiene/quadricyclane photoswitches. Emphasis is put on the energy difference between the two isomers and the optical absorption as these are central to the application of the systems in solar energy storage. Using a combined classical molecular dynamics and quantum mechanical/molecular mechanical computational scheme, we showcase that the dynamic effects of solvation are important. In particular, it is found that standard implicit solvation models generally underestimate the energy difference between the two isomers and overestimate the strength of the absorption, while the explicit solvation spectra are also less red-shifted than those obtained using implicit solvation models. We also find that the absorption spectra of the two systems are strongly correlated with specific dihedral angles. Altogether, this highlights the importance of including the dynamic effects of solvation., QC 20240412

Published
2024
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62. A variational reformulation of molecular properties in electronic-structure theory

Author

Jørgensen, Poul, Olsen, Jeppe, Johansen, Magnus Bukhave, von Buchwald, Theo Juncker, Hillers-Bendtsen, Andreas Erbs, Mikkelsen, Kurt V., Helgaker, Trygve, Jørgensen, Poul, Olsen, Jeppe, Johansen, Magnus Bukhave, von Buchwald, Theo Juncker, Hillers-Bendtsen, Andreas Erbs, Mikkelsen, Kurt V., and Helgaker, Trygve

Abstract

Conventional quantum-mechanical calculations of molecular properties, such as dipole moments and electronic excitation energies, give errors that depend linearly on the error in the wave function. An exception is the electronic energy, whose error depends quadratically on the error in wave function. We here describe how all properties may be calculated with a quadratic error, by setting up a variational Lagrangian for the property of interest. Because the construction of the Lagrangian is less expensive than the calculation of the wave function, this approach substantially improves the accuracy of quantum-chemical calculations without increasing cost. As illustrated for excitation energies, this approach enables the accurate calculation of molecular properties for larger systems, with a short time-to-solution and in a manner well suited for modern computer architectures.

Published
2024

63. Cluster perturbation theory IX:Perturbation series for the coupled cluster singles and doubles ground state energy

Author

Hillers-Bendtsen, Andreas Erbs, Jensen, Frank, Mikkelsen, Kurt V., Olsen, Jeppe, Jørgensen, Poul, Hillers-Bendtsen, Andreas Erbs, Jensen, Frank, Mikkelsen, Kurt V., Olsen, Jeppe, and Jørgensen, Poul

Abstract

In this paper, we develop and analyze a number of perturbation series that target the coupled cluster singles and doubles (CCSD) ground state energy. We show how classical Møller–Plesset perturbation theory series can be restructured to target the CCSD energy based on a reference CCS calculation and how the corresponding cluster perturbation series differs from the classical Møller–Plesset perturbation series. Subsequently, we reformulate these series using the coupled cluster Lagrangian framework to obtain series, where fourth and fifth order energies are determined only using parameters through second order. To test the methods, we perform a series of test calculations on molecular photoswitches of both total energies and reaction energies. We find that the fifth order reaction energies are of CCSD quality and that they are of comparable accuracy to state-of-the-art approximations to the CCSD energy based on local pair natural orbitals. The advantage of the present approach over local correlation methods is the absence of user defined threshold parameters for neglecting or approximating contributions to the correlation energy. Fixed threshold parameters lead to discontinuous energy surfaces, although this effect is often small enough to be ignored, but the present approach has a differentiable energy that will facilitate derivation and implementation of gradients and higher derivatives. A further advantage is that the calculation of the perturbation correction is non-iterative and can, therefore, be calculated in parallel, leading to a short time-to-solution., In this paper, we develop and analyze a number of perturbation series that target the coupled cluster singles and doubles (CCSD) ground state energy. We show how classical Møller-Plesset perturbation theory series can be restructured to target the CCSD energy based on a reference CCS calculation and how the corresponding cluster perturbation series differs from the classical Møller-Plesset perturbation series. Subsequently, we reformulate these series using the coupled cluster Lagrangian framework to obtain series, where fourth and fifth order energies are determined only using parameters through second order. To test the methods, we perform a series of test calculations on molecular photoswitches of both total energies and reaction energies. We find that the fifth order reaction energies are of CCSD quality and that they are of comparable accuracy to state-of-the-art approximations to the CCSD energy based on local pair natural orbitals. The advantage of the present approach over local correlation methods is the absence of user defined threshold parameters for neglecting or approximating contributions to the correlation energy. Fixed threshold parameters lead to discontinuous energy surfaces, although this effect is often small enough to be ignored, but the present approach has a differentiable energy that will facilitate derivation and implementation of gradients and higher derivatives. A further advantage is that the calculation of the perturbation correction is non-iterative and can, therefore, be calculated in parallel, leading to a short time-to-solution.

Published
2024

64. Tensor Hypercontraction of Cluster Perturbation Theory:Quartic Scaling Perturbation Series for the Coupled Cluster Singles and Doubles Ground-State Energies

Author

Hillers-Bendtsen, Andreas Erbs, Mikkelsen, Kurt V., Martinez, Todd J., Hillers-Bendtsen, Andreas Erbs, Mikkelsen, Kurt V., and Martinez, Todd J.

Abstract

Even though cluster perturbation theory has been shown to be a robust noniterative alternative to coupled cluster theory, it is still plagued by high order polynomial computational scaling and the storage of higher order tensors. We present a proof-of-concept strategy for implementing a cluster perturbation theory ground-state energy series for the coupled cluster singles and doubles energy with N4 computational scaling using tensor hypercontraction (THC). The reduction in computational scaling by two orders is achieved by decomposing two electron repulsion integrals, doubles amplitudes and multipliers, as well as selected double intermediates to the THC format. Using the outlined strategy, we showcase that the THC pilot implementations retain numerical accuracy to within 1 kcal/mol relative to corresponding conventional and density fitting implementations, and we empirically verify the N4 scaling.

Published
2024

65. Investigation of Solvent Effects on the Molecular Energy Storage and Optical Properties of Bicyclooctadiene/Tetracyclooctane Photoswitches

Author

Hillers-Bendtsen, Andreas Erbs, Zhou, Yiwei, Mikkelsen, Kurt V., Hillers-Bendtsen, Andreas Erbs, Zhou, Yiwei, and Mikkelsen, Kurt V.

Abstract

In this paper, we investigate the effects of solvation on the solar energy storage properties of bicyclooctadiene/tetracyclooctane (BOD/TCO) photoswitches. The solvent effects on the thermochemical and optical properties are studied in cyclohexane, toluene, dichloromethane, ethanol, acetonitrile, and a vacuum using density functional theory and coupled cluster theory. Our results show that the energy storage capacity of the BOD/TCO system increases as the solvent polarity increases, and the change is more significant with an unsubstituted system. The energy storage capacity of the substituted system is not dependent on the polarity of the solvent. As the solvent polarity increases, the absorption peaks shift away from each other and the absorption intensities increase. Overall, the solvents improve the performance of the optical properties and the energy storage capacities of the BOD/TCO molecular solar thermal systems.

Published
2024

66. Positive feedbacks and alternative stable states in forest leaf types

Author

Zou, Y., Zohner, C., Averill, C., Ma, H., Merder, J., Berdugo, M., Bialic-Murphy, L., Mo, L., Brun, P., Zimmermann, N., Liang, J., de-Miguel, S., Nabuurs, G.-J., Reich, P., Niinements, U., Dahlgren, J., Kändler, G., Ratcliffe, S., Ruiz-Benito, P., de Zavala, M., Abegg, M., Adou Yao, Y., Alberti, G., Almeyda Zambrano, A., Alvarado, B., Alvarez-Dávila, E., Alvarez-Loayza, P., Alves, L., Ammer, C., Antón-Fernández, C., Araujo-Murakami, A., Arroyo, L., Avitabile, V., Aymard, G., Baker, T., Bałazy, R., Banki, O., Barroso, J., Bastian, M., Bastin, J.-F., Birigazzi, L., Birnbaum, P., Bitariho, R., Boeckx, P., Bongers, F., Bouriaud, O., Brancalion, P., Brandl, S., Brearley, F., Brienen, R., Broadbent, E., Bruelheide, H., Bussotti, F., Gatti, R., César, R., Cesljar, G., Chazdon, R., Chen, H., Chisholm, C., Cho, H., Cienciala, E., Clark, C., Clark, D., Colletta, G., Coomes, D., Valverde, F., Corral-Rivas, J., Crim, P., Cumming, J., Dayanandan, S., de Gasper, A., Decuyper, M., Derroire, G., DeVries, B., Djordjevic, I., Dolezal, J., Dourdain, A., Obiang, N., Enquist, B., Eyre, T., Fandohan, A., Fayle, T., Feldpausch, T., Ferreira, L., Finér, L., Fischer, M., Fletcher, C., Fridman, J., Frizzera, L., Gamarra, J., Gianelle, D., Glick, H., Harris, D., Hector, A., Hemp, A., Hengeveld, G., Hérault, B., Herbohn, J., Herold, M., Hillers, A., Honorio Coronado, E., Hui, C., Ibanez, T., Iêda, A., Imai, N., Jagodziński, A., Jaroszewicz, B., Johannsen, V., Joly, C., Jucker, T., Jung, I., Karminov, V., Kartawinata, K., Kearsley, E., Kenfack, D., Kennard, D., Kepfer-Rojas, S., Keppel, G., Khan, M., Killeen, T., Kim, H., Kitayama, K., Köhl, M., Korjus, H., Kraxner, F., Laarmann, D., Lang, M., Lewis, S., Lu, H., Lukina, N., Maitner, B., Malhi, Y., Marcon, E., Marimon, B., Marimon-Junior, B., Marshall, A., Martin, E., Kucher, D., Meave, J., Melo-Cruz, O., Mendoza, C., Merow, C., Mendoza, A., Moreno, V., Mukul, S., Mundhenk, P., Nava-Miranda, M., Neill, D., Neldner, V., Nevenic, R., Ngugi, M., Niklaus, P., Oleksyn, J., Ontikov, P., Ortiz-Malavasi, E., Pan, Y., Paquette, A., Parada-Gutierrez, A., Parfenova, E., Park, M., Parren, M., Parthasarathy, N., Peri, P., Pfautsch, S., Phillips, O., Picard, N., Piedade, M., Piotto, D., Pitman, N., Polo, I., Poorter, L., Poulsen, A., Poulsen, J., Pretzsch, H., Arevalo, F., Restrepo-Correa, Z., Rodeghiero, M., Rolim, S., Roopsind, A., Rovero, F., Rutishauser, E., Saikia, P., Salas-Eljatib, C., Saner, P., Schall, P., Schelhaas, M., Shchepashchenko, D., Scherer-Lorenzen, M., Schmid, B., Schöngart, J., Searle, E., Seben, V., Serra-Diaz, J., Sheil, D., Shvidenko, A., Silva-Espejo, J., Silveira, M., Singh, J., Sist, P., Slik, F., Sonké, B., Souza, A., Miscicki, S., Stereńczak, K., Svenning, J., Svoboda, M., Swanepoel, B., Targhetta, N., Tchebakova, N., ter Steege, H., Thomas, R., Tikhonova, E., Umunay, P., Usoltsev, V., Valencia, R., Valladares, F., van der Plas, F., Van Do, T., van Nuland, M., Vasquez, R., Verbeeck, H., Viana, H., Vibrans, A., Vieira, S., von Gadow, K., Wang, H., Watson, J., Werner, G., Westerlund, B., Wiser, S., Wittmann, F., Woell, H., Wortel, V., Zagt, R., Zawiła-Niedźwiecki, T., Zhang, C., Zhao, X., Zhou, M., Zhu, Z., Zo-Bi, I., Crowther, T., Zou, Y., Zohner, C., Averill, C., Ma, H., Merder, J., Berdugo, M., Bialic-Murphy, L., Mo, L., Brun, P., Zimmermann, N., Liang, J., de-Miguel, S., Nabuurs, G.-J., Reich, P., Niinements, U., Dahlgren, J., Kändler, G., Ratcliffe, S., Ruiz-Benito, P., de Zavala, M., Abegg, M., Adou Yao, Y., Alberti, G., Almeyda Zambrano, A., Alvarado, B., Alvarez-Dávila, E., Alvarez-Loayza, P., Alves, L., Ammer, C., Antón-Fernández, C., Araujo-Murakami, A., Arroyo, L., Avitabile, V., Aymard, G., Baker, T., Bałazy, R., Banki, O., Barroso, J., Bastian, M., Bastin, J.-F., Birigazzi, L., Birnbaum, P., Bitariho, R., Boeckx, P., Bongers, F., Bouriaud, O., Brancalion, P., Brandl, S., Brearley, F., Brienen, R., Broadbent, E., Bruelheide, H., Bussotti, F., Gatti, R., César, R., Cesljar, G., Chazdon, R., Chen, H., Chisholm, C., Cho, H., Cienciala, E., Clark, C., Clark, D., Colletta, G., Coomes, D., Valverde, F., Corral-Rivas, J., Crim, P., Cumming, J., Dayanandan, S., de Gasper, A., Decuyper, M., Derroire, G., DeVries, B., Djordjevic, I., Dolezal, J., Dourdain, A., Obiang, N., Enquist, B., Eyre, T., Fandohan, A., Fayle, T., Feldpausch, T., Ferreira, L., Finér, L., Fischer, M., Fletcher, C., Fridman, J., Frizzera, L., Gamarra, J., Gianelle, D., Glick, H., Harris, D., Hector, A., Hemp, A., Hengeveld, G., Hérault, B., Herbohn, J., Herold, M., Hillers, A., Honorio Coronado, E., Hui, C., Ibanez, T., Iêda, A., Imai, N., Jagodziński, A., Jaroszewicz, B., Johannsen, V., Joly, C., Jucker, T., Jung, I., Karminov, V., Kartawinata, K., Kearsley, E., Kenfack, D., Kennard, D., Kepfer-Rojas, S., Keppel, G., Khan, M., Killeen, T., Kim, H., Kitayama, K., Köhl, M., Korjus, H., Kraxner, F., Laarmann, D., Lang, M., Lewis, S., Lu, H., Lukina, N., Maitner, B., Malhi, Y., Marcon, E., Marimon, B., Marimon-Junior, B., Marshall, A., Martin, E., Kucher, D., Meave, J., Melo-Cruz, O., Mendoza, C., Merow, C., Mendoza, A., Moreno, V., Mukul, S., Mundhenk, P., Nava-Miranda, M., Neill, D., Neldner, V., Nevenic, R., Ngugi, M., Niklaus, P., Oleksyn, J., Ontikov, P., Ortiz-Malavasi, E., Pan, Y., Paquette, A., Parada-Gutierrez, A., Parfenova, E., Park, M., Parren, M., Parthasarathy, N., Peri, P., Pfautsch, S., Phillips, O., Picard, N., Piedade, M., Piotto, D., Pitman, N., Polo, I., Poorter, L., Poulsen, A., Poulsen, J., Pretzsch, H., Arevalo, F., Restrepo-Correa, Z., Rodeghiero, M., Rolim, S., Roopsind, A., Rovero, F., Rutishauser, E., Saikia, P., Salas-Eljatib, C., Saner, P., Schall, P., Schelhaas, M., Shchepashchenko, D., Scherer-Lorenzen, M., Schmid, B., Schöngart, J., Searle, E., Seben, V., Serra-Diaz, J., Sheil, D., Shvidenko, A., Silva-Espejo, J., Silveira, M., Singh, J., Sist, P., Slik, F., Sonké, B., Souza, A., Miscicki, S., Stereńczak, K., Svenning, J., Svoboda, M., Swanepoel, B., Targhetta, N., Tchebakova, N., ter Steege, H., Thomas, R., Tikhonova, E., Umunay, P., Usoltsev, V., Valencia, R., Valladares, F., van der Plas, F., Van Do, T., van Nuland, M., Vasquez, R., Verbeeck, H., Viana, H., Vibrans, A., Vieira, S., von Gadow, K., Wang, H., Watson, J., Werner, G., Westerlund, B., Wiser, S., Wittmann, F., Woell, H., Wortel, V., Zagt, R., Zawiła-Niedźwiecki, T., Zhang, C., Zhao, X., Zhou, M., Zhu, Z., Zo-Bi, I., and Crowther, T.

Abstract

The emergence of alternative stable states in forest systems has significant implications for the functioning and structure of the terrestrial biosphere, yet empirical evidence remains scarce. Here, we combine global forest biodiversity observations and simulations to test for alternative stable states in the presence of evergreen and deciduous forest types. We reveal a bimodal distribution of forest leaf types across temperate regions of the Northern Hemisphere that cannot be explained by the environment alone, suggesting signatures of alternative forest states. Moreover, we empirically demonstrate the existence of positive feedbacks in tree growth, recruitment and mortality, with trees having 4–43% higher growth rates, 14–17% higher survival rates and 4–7 times higher recruitment rates when they are surrounded by trees of their own leaf type. Simulations show that the observed positive feedbacks are necessary and sufficient to generate alternative forest states, which also lead to dependency on history (hysteresis) during ecosystem transition from evergreen to deciduous forests and vice versa. We identify hotspots of bistable forest types in evergreen-deciduous ecotones, which are likely driven by soil-related positive feedbacks. These findings are integral to predicting the distribution of forest biomes, and aid to our understanding of biodiversity, carbon turnover, and terrestrial climate feedbacks.

Published
2024
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67. Massively parallel GPU enabled third-order cluster perturbation excitation energies for cost-effective large scale excitation energy calculations.

Author

Hillers-Bendtsen, Andreas Erbs, Bykov, Dmytro, Barnes, Ashleigh, Liakh, Dmitry, Corzo, Hector H., Olsen, Jeppe, Jørgensen, Poul, and Mikkelsen, Kurt V.

Subjects
*PERTURBATION theory, *CLOCKS & watches
Abstract

We present here a massively parallel implementation of the recently developed CPS(D-3) excitation energy model that is based on cluster perturbation theory. The new algorithm extends the one developed in Baudin et al. [J. Chem. Phys., 150, 134110 (2019)] to leverage multiple nodes and utilize graphical processing units for the acceleration of heavy tensor contractions. Furthermore, we show that the extended algorithm scales efficiently with increasing amounts of computational resources and that the developed code enables CPS(D-3) excitation energy calculations on large molecular systems with a low time-to-solution. More specifically, calculations on systems with over 100 atoms and 1000 basis functions are possible in a few hours of wall clock time. This establishes CPS(D-3) excitation energies as a computationally efficient alternative to those obtained from the coupled-cluster singles and doubles model. [ABSTRACT FROM AUTHOR]

Published
2023
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68. Norbornadiene‐Quadricyclane Photoswitches with Enhanced Solar Spectrum Match.

Author

Aslam, Adil S., Muhammad, Lidiya M., Erbs Hillers‐Bendtsen, Andreas, Mikkelsen, Kurt V., and Moth‐Poulsen, Kasper

Subjects
MOLECULAR structure, DENSITY functional theory, LIGHT absorption, ABSORPTION spectra, ENERGY storage
Abstract

Herein, we report monomeric and dimeric norbornadiene‐quadricyclane molecular photoswitch systems intended for molecular solar thermal applications. A series of six new norbornadiene derivatives conjugated with benzothiadiazole as the acceptor unit and dithiafulvene as the donor unit were synthesized and fully characterized. The photoswitches were evaluated by experimentally and theoretically measuring optical absorption profiles and thermal conversion of quadricyclane to norbornadiene. Computational insight by density functional theory calculations at the M06‐2X/def2‐SVPD level of theory provided geometries, storage energies, UV‐vis absorption spectra, and HOMO‐LUMO levels that are used to describe the function of the molecular systems. The studied molecules exhibit absorption onset ranging from 416 nm to 595 nm due to a systemic change in their donor‐acceptor character. This approach was advantageous due to the introduction of benzothiadiazole and the dimeric nature of molecular structures. The best‐performing system has a half‐life of 3 days with quantum yields over 50 %. [ABSTRACT FROM AUTHOR]

Published
2024
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69. „Bondstripping" durch Luxemburger SICAV mit KGaA als Gesellschafterin – Urteilsanmerkung zu BFH v. 7.2.2024 – I R 8/19, FR 2024, 721.

Author

Bärsch, Sven-Eric and Hillers, Jan-Hendrik

Subjects
FEDERAL court decisions, TAX planning, TAX courts, JUDGE-made law, STOCKHOLDERS, DOUBLE taxation
Abstract

Copyright of FinanzRundschau is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2024
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71. Life in the spray zone – overlooked diversity in West African torrent-frogs (Anura, Odontobatrachidae, Odontobatrachus)

Author

Barej, Michael F, Schmitz, Andreas, Penner, Johannes, Doumbia, Joseph, Sandberger-Loua, Laura, Petersen, Mareike, Brede, Christian, Emmrich, Mike, Kouamé, N'Goran Germain, Hillers, Annika, Gonwouo, Nono Legrand, Nopper, Joachim, Adeba, Patrick Joel, Bangoura, Mohamed Alhassane, Gage, Ceri, Anderson, Gail, Rödel, Mark-Oliver, and Pensoft Publishers

Subjects
Amphibia, Biodiversity hotspot, new species, rainforest, taxonomy, Upper Guinea
Published
2015

73. Erratum to Reply to “Comment on ‘Sources of Long-Range Anthropogenic Noise in Southern California and Implications for Tectonic Tremor Detection’ by Asaf Inbal, Tudor Cristea-Platon, Jean-Paul Ampuero, Gregor Hillers, Duncan Agnew, and Susan E. Hough” by Allie Hutchison, Yijian Zhou, and Abhijit Ghosh

Author

Inbal, Asaf, primary, Cristea-Platon, Tudor, additional, Ampuero, Jean-Paul, additional, Hillers, Gregor, additional, and Agnew, Duncan, additional

Published
2024
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78. Computational investigation of photoswitch conjugates for molecular solar energy storage

Author

European Commission, Danish Council for Independent Research, Agencia Estatal de Investigación (España), Elholm, Jacob Lynge [0000-0002-6441-1664], Liasi, Zacharias [0000-0001-6722-5640], Mikkelsen, Marie Kathrine [0000-0003-4579-6367], Hillers-Bendtsen, Andreas Erbs [0000-0003-4960-8802], Mikkelsen, Kurt V. [0000-0003-4090-7697], Elholm, Jacob Lynge, Liasi, Zacharias, Mikkelsen, Marie Kathrine, Hillers-Bendtsen, Andreas Erbs, Mikkelsen, Kurt V., European Commission, Danish Council for Independent Research, Agencia Estatal de Investigación (España), Elholm, Jacob Lynge [0000-0002-6441-1664], Liasi, Zacharias [0000-0001-6722-5640], Mikkelsen, Marie Kathrine [0000-0003-4579-6367], Hillers-Bendtsen, Andreas Erbs [0000-0003-4960-8802], Mikkelsen, Kurt V. [0000-0003-4090-7697], Elholm, Jacob Lynge, Liasi, Zacharias, Mikkelsen, Marie Kathrine, Hillers-Bendtsen, Andreas Erbs, and Mikkelsen, Kurt V.

Abstract

Solar energy conversion and storage are vital for combating climate change. Molecular solar thermal systems offer a promising solution, where energy is stored in molecular compounds. This study investigates dyad molecular photoswitches by combining bicyclooctadiene/tetracyclooctane and dihydroazulene/vinylheptafulvene systems with phenyl and cyano groups. Density functional theory calculations were employed to determine molecular properties and consider solvation effects in toluene and dichloromethane. The results show that the combined systems have a predicted storage energy of up to 206.14 kJ mol-1 and an absorption peak at 390.26 nm with appreciable intensity. These dyad photoswitches exhibit favorable properties for molecular solar thermal storage and other applications. A comparison with individual photoswitches reveals advantages and disadvantages. The most effective conjugate has a slightly lower storage density than an equal mixture of individual systems, but it demonstrates better absorption characteristics, with improved overlap with the solar spectrum and higher absorption intensity. These findings contribute to the understanding of dyad molecular photoswitches, showcasing their potential for advanced energy storage and conversion technologies.

Published
2023

79. Exploring the impact of select anchor groups for norbornadiene/quadricyclane single-molecule switches

Author

ICREA Acadèmia, European Research Council, European Commission, Agencia Estatal de Investigación (España), Ghasemi, Shima [0000-0001-7915-1546], Ornago, Luca [0000-0001-5293-2887], Liasi, Zacharias [0000-0001-6722-5640], Johansen, Magnus Bukhave [0000-0002-4321-4493], Buchwald, Theo Juncker von [0000-0002-4812-7073], Hillers-Bendtsen, Andreas Erbs [0000-0003-4960-8802], Poel, Sebastiaan van der [0009-0009-6323-3665], Hölzel, Helen [0000-0003-2312-9934], Wang, Zhihang [0000-0002-9961-3346], Amombo Noa, Francoise M. [0000-0001-8361-3432], Öhrström, Lars [0000-0002-6420-2141], Mikkelsen, Kurt V. [0000-0003-4090-7697], Zant, Herre S.J. van der [0000-0002-5385-0282], Lara Avila, Samuel [0000-0002-8331-718X], Moth-Poulsen, Kasper [0000-0003-4018-4927], Ghasemi, Shima, Ornago, Luca, Liasi, Zacharias, Johansen, Magnus Bukhave, Buchwald, Theo Juncker von, Hillers-Bendtsen, Andreas Erbs, Poel, Sebastiaan van der, Hölzel, Helen, Wang, Zhihang, Amombo Noa, Francoise M., Öhrström, Lars, Mikkelsen, Kurt V., Zant, Herre S.J. van der, Lara Avila, Samuel, Moth-Poulsen, Kasper, ICREA Acadèmia, European Research Council, European Commission, Agencia Estatal de Investigación (España), Ghasemi, Shima [0000-0001-7915-1546], Ornago, Luca [0000-0001-5293-2887], Liasi, Zacharias [0000-0001-6722-5640], Johansen, Magnus Bukhave [0000-0002-4321-4493], Buchwald, Theo Juncker von [0000-0002-4812-7073], Hillers-Bendtsen, Andreas Erbs [0000-0003-4960-8802], Poel, Sebastiaan van der [0009-0009-6323-3665], Hölzel, Helen [0000-0003-2312-9934], Wang, Zhihang [0000-0002-9961-3346], Amombo Noa, Francoise M. [0000-0001-8361-3432], Öhrström, Lars [0000-0002-6420-2141], Mikkelsen, Kurt V. [0000-0003-4090-7697], Zant, Herre S.J. van der [0000-0002-5385-0282], Lara Avila, Samuel [0000-0002-8331-718X], Moth-Poulsen, Kasper [0000-0003-4018-4927], Ghasemi, Shima, Ornago, Luca, Liasi, Zacharias, Johansen, Magnus Bukhave, Buchwald, Theo Juncker von, Hillers-Bendtsen, Andreas Erbs, Poel, Sebastiaan van der, Hölzel, Helen, Wang, Zhihang, Amombo Noa, Francoise M., Öhrström, Lars, Mikkelsen, Kurt V., Zant, Herre S.J. van der, Lara Avila, Samuel, and Moth-Poulsen, Kasper

Abstract

To achieve the ultimate limit of device miniaturization, it is necessary to have a comprehensive understanding of the structure-property relationship in functional molecular systems used in single-molecule electronics. This study reports the synthesis and characterization of a novel series of norbornadiene derivatives capped with thioether and thioester anchor groups. Utilizing the mechanically controllable break junction technique, the impact of these capping groups on conductance across single-molecule junctions is investigated. Among the selection of anchor groups, norbornadiene capped with thioacetate and tert-butyl groups exhibits higher conductance (G ≈ 4 × 10−4 G0) compared to methyl thioether (G ≈ 2 × 10−4 G0). Electronic transmission through the considered set of single-molecule junctions has been simulated. The computational results for electron transport across these junctions align closely with the experimental findings, with the thioacetate- and tert-butyl-substituted systems outperforming the methyl thioether-capped derivative. In terms of junction stability, the methyl thioether-capped system is the most resilient, maintaining consistent conductance even after approximately 10 000 cycles. Meanwhile, the likelihood of observing molecular plateaus in both the thioacetate- and tert-butyl-substituted systems declines over time. These findings substantially advance both the design and understanding of functional molecular systems in the realm of single-molecule electronics, particularly in the context of molecular photoswitches.

Published
2023

81. Die Besteuerung von Begünstigten einer ausländischen Familienstiftung nach § 15 AStG — Der neue AEAStG zu § 15 AStG.

Author

Kühn, Michal Fabian and Hillers, Jan-Hendrik

Subjects
INCOME, FAMILY foundations, STATE taxation, TAXATION, DOCUMENTATION
Abstract

Copyright of Die Unternehmensbesteuerung (Ubg) is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2024
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83. The global biogeography of tree leaf form and habit

Author

Ma, Haozhi, primary, Crowther, Thomas W., additional, Mo, Lidong, additional, Maynard, Daniel S., additional, Renner, Susanne S., additional, van den Hoogen, Johan, additional, Zou, Yibiao, additional, Liang, Jingjing, additional, de-Miguel, Sergio, additional, Nabuurs, Gert-Jan, additional, Reich, Peter B., additional, Niinemets, Ülo, additional, Abegg, Meinrad, additional, Adou Yao, Yves C., additional, Alberti, Giorgio, additional, Almeyda Zambrano, Angelica M., additional, Alvarado, Braulio Vilchez, additional, Alvarez-Dávila, Esteban, additional, Alvarez-Loayza, Patricia, additional, Alves, Luciana F., additional, Ammer, Christian, additional, Antón-Fernández, Clara, additional, Araujo-Murakami, Alejandro, additional, Arroyo, Luzmila, additional, Avitabile, Valerio, additional, Aymard, Gerardo A., additional, Baker, Timothy R., additional, Bałazy, Radomir, additional, Banki, Olaf, additional, Barroso, Jorcely G., additional, Bastian, Meredith L., additional, Bastin, Jean-Francois, additional, Birigazzi, Luca, additional, Birnbaum, Philippe, additional, Bitariho, Robert, additional, Boeckx, Pascal, additional, Bongers, Frans, additional, Bouriaud, Olivier, additional, Brancalion, Pedro H. S., additional, Brandl, Susanne, additional, Brearley, Francis Q., additional, Brienen, Roel, additional, Broadbent, Eben N., additional, Bruelheide, Helge, additional, Bussotti, Filippo, additional, Cazzolla Gatti, Roberto, additional, César, Ricardo G., additional, Cesljar, Goran, additional, Chazdon, Robin, additional, Chen, Han Y. H., additional, Chisholm, Chelsea, additional, Cho, Hyunkook, additional, Cienciala, Emil, additional, Clark, Connie, additional, Clark, David, additional, Colletta, Gabriel D., additional, Coomes, David A., additional, Valverde, Fernando Cornejo, additional, Corral-Rivas, José J., additional, Crim, Philip M., additional, Cumming, Jonathan R., additional, Dayanandan, Selvadurai, additional, de Gasper, André L., additional, Decuyper, Mathieu, additional, Derroire, Géraldine, additional, DeVries, Ben, additional, Djordjevic, Ilija, additional, Dolezal, Jiri, additional, Dourdain, Aurélie, additional, Engone Obiang, Nestor Laurier, additional, Enquist, Brian J., additional, Eyre, Teresa J., additional, Fandohan, Adandé Belarmain, additional, Fayle, Tom M., additional, Feldpausch, Ted R., additional, Ferreira, Leandro V., additional, Finér, Leena, additional, Fischer, Markus, additional, Fletcher, Christine, additional, Fridman, Jonas, additional, Frizzera, Lorenzo, additional, Gamarra, Javier G. P., additional, Gianelle, Damiano, additional, Glick, Henry B., additional, Harris, David J., additional, Hector, Andrew, additional, Hemp, Andreas, additional, Hengeveld, Geerten, additional, Hérault, Bruno, additional, Herbohn, John L., additional, Herold, Martin, additional, Hillers, Annika, additional, Honorio Coronado, Eurídice N., additional, Hui, Cang, additional, Ibanez, Thomas T., additional, Amaral, Iêda, additional, Imai, Nobuo, additional, Jagodziński, Andrzej M., additional, Jaroszewicz, Bogdan, additional, Johannsen, Vivian Kvist, additional, Joly, Carlos A., additional, Jucker, Tommaso, additional, Jung, Ilbin, additional, Karminov, Viktor, additional, Kartawinata, Kuswata, additional, Kearsley, Elizabeth, additional, Kenfack, David, additional, Kennard, Deborah K., additional, Kepfer-Rojas, Sebastian, additional, Keppel, Gunnar, additional, Khan, Mohammed Latif, additional, Killeen, Timothy J., additional, Kim, Hyun Seok, additional, Kitayama, Kanehiro, additional, Köhl, Michael, additional, Korjus, Henn, additional, Kraxner, Florian, additional, Kucher, Dmitry, additional, Laarmann, Diana, additional, Lang, Mait, additional, Lewis, Simon L., additional, Lu, Huicui, additional, Lukina, Natalia V., additional, Maitner, Brian S., additional, Malhi, Yadvinder, additional, Marcon, Eric, additional, Marimon, Beatriz Schwantes, additional, Marimon-Junior, Ben Hur, additional, Marshall, Andrew R., additional, Martin, Emanuel H., additional, Meave, Jorge A., additional, Melo-Cruz, Omar, additional, Mendoza, Casimiro, additional, Merow, Cory, additional, Monteagudo Mendoza, Abel, additional, Moreno, Vanessa S., additional, Mukul, Sharif A., additional, Mundhenk, Philip, additional, Nava-Miranda, María Guadalupe, additional, Neill, David, additional, Neldner, Victor J., additional, Nevenic, Radovan V., additional, Ngugi, Michael R., additional, Niklaus, Pascal A., additional, Oleksyn, Jacek, additional, Ontikov, Petr, additional, Ortiz-Malavasi, Edgar, additional, Pan, Yude, additional, Paquette, Alain, additional, Parada-Gutierrez, Alexander, additional, Parfenova, Elena I., additional, Park, Minjee, additional, Parren, Marc, additional, Parthasarathy, Narayanaswamy, additional, Peri, Pablo L., additional, Pfautsch, Sebastian, additional, Phillips, Oliver L., additional, Picard, Nicolas, additional, Piedade, Maria Teresa F., additional, Piotto, Daniel, additional, Pitman, Nigel C. A., additional, Mendoza-Polo, Irina, additional, Poulsen, Axel D., additional, Poulsen, John R., additional, Pretzsch, Hans, additional, Ramirez Arevalo, Freddy, additional, Restrepo-Correa, Zorayda, additional, Rodeghiero, Mirco, additional, Rolim, Samir G., additional, Roopsind, Anand, additional, Rovero, Francesco, additional, Rutishauser, Ervan, additional, Saikia, Purabi, additional, Salas-Eljatib, Christian, additional, Saner, Philippe, additional, Schall, Peter, additional, Schelhaas, Mart-Jan, additional, Schepaschenko, Dmitry, additional, Scherer-Lorenzen, Michael, additional, Schmid, Bernhard, additional, Schöngart, Jochen, additional, Searle, Eric B., additional, Seben, Vladimír, additional, Serra-Diaz, Josep M., additional, Sheil, Douglas, additional, Shvidenko, Anatoly Z., additional, Silva-Espejo, Javier E., additional, Silveira, Marcos, additional, Singh, James, additional, Sist, Plinio, additional, Slik, Ferry, additional, Sonké, Bonaventure, additional, Souza, Alexandre F., additional, Miścicki, Stanislaw, additional, Stereńczak, Krzysztof J., additional, Svenning, Jens-Christian, additional, Svoboda, Miroslav, additional, Swanepoel, Ben, additional, Targhetta, Natalia, additional, Tchebakova, Nadja, additional, ter Steege, Hans, additional, Thomas, Raquel, additional, Tikhonova, Elena, additional, Umunay, Peter M., additional, Usoltsev, Vladimir A., additional, Valencia, Renato, additional, Valladares, Fernando, additional, van der Plas, Fons, additional, Van Do, Tran, additional, van Nuland, Michael E., additional, Vasquez, Rodolfo M., additional, Verbeeck, Hans, additional, Viana, Helder, additional, Vibrans, Alexander C., additional, Vieira, Simone, additional, von Gadow, Klaus, additional, Wang, Hua-Feng, additional, Watson, James V., additional, Werner, Gijsbert D. A., additional, Westerlund, Bertil, additional, Wiser, Susan K., additional, Wittmann, Florian, additional, Woell, Hannsjoerg, additional, Wortel, Verginia, additional, Zagt, Roderick, additional, Zawiła-Niedźwiecki, Tomasz, additional, Zhang, Chunyu, additional, Zhao, Xiuhai, additional, Zhou, Mo, additional, Zhu, Zhi-Xin, additional, Zo-Bi, Irie C., additional, and Zohner, Constantin M., additional

Published
2023
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87. Near-surface structure of the North Anatolian Fault zone from Rayleigh and Love wave tomography using ambient seismic noise

Author

G. Taylor, S. Rost, G. A. Houseman, and G. Hillers

Subjects
Geology, QE1-996.5, Stratigraphy, QE640-699
Abstract

We use observations of surface waves in the ambient noise field recorded at a dense seismic array to image the North Anatolian Fault zone (NAFZ) in the region of the 1999 magnitude 7.6 Izmit earthquake in western Turkey. The NAFZ is a major strike-slip fault system extending ∼1200 km across northern Turkey that poses a high level of seismic hazard, particularly to the city of Istanbul. We obtain maps of phase velocity variation using surface wave tomography applied to Rayleigh and Love waves and construct high-resolution images of S-wave velocity in the upper 10 km of a 70 × 30 km region around Lake Sapanca. We observe low S-wave velocities ( km s−1) associated with the Adapazari and Pamukova sedimentary basins, as well as the northern branch of the NAFZ. In the Armutlu Block, between the two major branches of the NAFZ, we image higher velocities (>3.2 km s−1) associated with a shallow crystalline basement. We measure azimuthal anisotropy in our phase velocity observations, with the fast direction seeming to align with the strike of the fault at periods shorter than 4 s. At longer periods up to 10 s, the fast direction aligns with the direction of maximum extension for the region (∼45∘). The signatures of both the northern and southern branches of the NAFZ are clearly associated with strong gradients in seismic velocity that also denote the boundaries of major tectonic units. Our results support the conclusion that the development of the NAFZ has exploited this pre-existing contrast in physical properties.

Published
2019
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92. Cluster perturbation theory. VIII. First order properties for a coupled cluster state.

Author

Hillers-Bendtsen, Andreas Erbs, Høyer, Nicolai Machholdt, Kjeldal, Frederik Ørsted, Mikkelsen, Kurt V., Olsen, Jeppe, and Jørgensen, Poul

Subjects
*PERTURBATION theory
Abstract

We have extended cluster perturbation (CP) theory to comprehend the calculation of first order properties (FOPs). We have determined CP FOP series where FOPs are determined as a first energy derivative and also where the FOPs are determined as a generalized expectation value of the external perturbation operator over the coupled cluster state and its biorthonormal multiplier state. For S(D) orbital excitation spaces, we find that the CP series for FOPs that are determined as a first derivative, in general, in second order have errors of a few percent in the singles and doubles correlation contribution relative to the targeted coupled cluster (CC) results. For a SD(T) orbital excitation space, we find that the CP series for FOPs determined as a generalized expectation value in second order have errors of about ten percent in the triples correlation contribution relative to the targeted CC results. These second order models, therefore, constitute viable alternatives for determining high quality FOPs. [ABSTRACT FROM AUTHOR]

Published
2022
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93. Cluster perturbation theory. VII. The convergence of cluster perturbation expansions.

Author

Olsen, Jeppe, Hillers-Bendtsen, Andreas Erbs, Kjeldal, Frederik Ørsted, Høyer, Nicolai Machholdt, Mikkelsen, Kurt V., and Jørgensen, Poul

Subjects
*PERTURBATION theory, *LAGRANGE equations, *SMALL molecules, *QUANTUM perturbations
Abstract

The convergence of the recently developed cluster perturbation (CP) expansions [Pawlowski et al., J. Chem. Phys. 150, 134108 (2019)] is analyzed with the double purpose of developing the mathematical tools and concepts needed to describe these expansions at general order and to identify the factors that define the rate of convergence of CP series. To this end, the CP energy, amplitude, and Lagrangian multiplier equations as a function of the perturbation strength are developed. By determining the critical points, defined as the perturbation strengths for which the Jacobian becomes singular, the rate of convergence and the intruder and critical states are determined for five small molecules: BH, CO, H2O, NH3, and HF. To describe the patterns of convergence for these expansions at orders lower than the high-order asymptotic limit, a model is developed where the perturbation corrections arise from two critical points. It is shown that this model allows for rationalization of the behavior of the perturbation corrections at much lower order than required for the onset of the asymptotic convergence. For the H2O, CO, and HF molecules, the pattern and rate of convergence are defined by critical states where the Fock-operator underestimates the excitation energies, whereas the pattern and rate of convergence for BH are defined by critical states where the Fock-operator overestimates the excitation energy. For the NH3 molecule, both forms of critical points are required to describe the convergence behavior up to at least order 25. [ABSTRACT FROM AUTHOR]

Published
2022
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94. Cluster perturbation theory. VI. Ground-state energy series using the Lagrangian.

Author

Høyer, Nicolai Machholdt, Kjeldal, Frederik Ørsted, Hillers-Bendtsen, Andreas Erbs, Mikkelsen, Kurt V., Olsen, Jeppe, and Jørgensen, Poul

Subjects
PERTURBATION theory, ENERGY consumption, STANDARD & Poor's 500 Index, EXCITED states
Abstract

We have extended cluster perturbation (CP) theory to comprehend the Lagrangian framework of coupled cluster (CC) theory and derived the CP Lagrangian energy series (LCP) where the 2n + 1/2n + 2 rules for the cluster amplitudes and multipliers are used to get the energy corrections. We have also developed the variational CP ( L C P ) series, where the total cluster amplitudes and multipliers are determined through the same orders as in the LCP series, but the energy is obtained by inserting the total cluster amplitudes and multipliers in the Lagrangian. The energies of the L C P series have errors that are bilinear in the errors of the total cluster amplitudes and multipliers. Test calculations have been performed for S(D) and SD(T) orbital excitation spaces. With the exception of molecular systems that have a low lying doubly excited state compared to the electronic ground state configuration, we find that the fourth order models L C P S (D−4), L C P S D (T−4), and LCPSD(T−4) give energies of CC target state quality. For the L C P S (D−4) model, CC target state quality is obtained as the L C P S (D−4) calculation determines more than 99.7% of the coupled cluster singles and doubles (CCSD) correlation energy as the numerical deviations of the L C P S (D−4) energy from the CCSD energy were more than an order of magnitude smaller than the triples correlation contribution. For the L C P S D (T−4) and LCPSD(T−4) models, CC target state quality was obtained, given that the L C P S D (T−4) and LCPSD(T−4) calculations recover more than 99% of the coupled cluster singles doubles and triples (CCSDT) correlation contribution and as the numerical deviations of the L C P S D (T−4) and LCPSD(T−4) energies from the CCSDT energy were nearly and order of magnitude smaller than the quadruples correlation contribution. We, thus, suggest that the fourth order models may replace the full target CC models with no or very limited loss of accuracy. [ABSTRACT FROM AUTHOR]

Published
2022
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97. Obesity-Activated Adipose-Derived Stromal Cells Promote Breast Cancer Growth and Invasion

Author

Lauren E. Hillers, Joseph V. D'Amato, Tamara Chamberlin, Gretchen Paderta, and Lisa M. Arendt

Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Obese women diagnosed with breast cancer have an increased risk for metastasis, and the underlying mechanisms are not well established. Within the mammary gland, adipose-derived stromal cells (ASCs) are heterogeneous cells with the capacity to differentiate into multiple mesenchymal lineages. To study the effects of obesity on ASCs, mice were fed a control diet (CD) or high-fat diet (HFD) to induce obesity, and ASCs were isolated from the mammary glands of lean and obese mice. We observed that obesity increased ASCs proliferation, decreased differentiation potential, and upregulated expression of α-smooth muscle actin, a marker of activated fibroblasts, compared to ASCs from lean mice. To determine how ASCs from obese mice impacted tumor growth, we mixed ASCs isolated from CD- or HFD-fed mice with mammary tumor cells and injected them into the mammary glands of lean mice. Tumor cells mixed with ASCs from obese mice grew significantly larger tumors and had increased invasion into surrounding adipose tissue than tumor cells mixed with control ASCs. ASCs from obese mice demonstrated enhanced tumor cell invasion in culture, a phenotype associated with increased expression of insulin-like growth factor-1 (IGF-1) and abrogated by IGF-1 neutralizing antibodies. Weight loss induced in obese mice significantly decreased expression of IGF-1 from ASCs and reduced the ability of the ASCs to induce an invasive phenotype. Together, these results suggest that obesity enhances local invasion of breast cancer cells through increased expression of IGF-1 by mammary ASCs, and weight loss may reverse this tumor-promoting phenotype.

Published
2018
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