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2,253 results on '"Higgins, S"'

1. The Continuous Electron Beam Accelerator Facility at 12 GeV

Author

Adderley, P. A., Ahmed, S., Allison, T., Bachimanchi, R., Baggett, K., BastaniNejad, M., Bevins, B., Bevins, M., Bickley, M., Bodenstein, R. M., Bogacz, S. A., Bruker, M., Burrill, A., Cardman, L., Creel, J., Chao, Y. -C., Cheng, G., Ciovati, G., Chattopadhyay, S., Clark, J., Clemens, W. A., Croke, G., Daly, E., Davis, G. K., Delayen, J., De Silva, S. U., Dickson, R., Diaz, M., Drury, M., Doolittle, L., Douglas, D., Feldl, E., Fischer, J., Freyberger, A., Ganni, V., Geng, R. L., Ginsburg, C., Gomez, J., Grames, J., Gubeli, J., Guo, J., Hannon, F., Hansknecht, J., Harwood, L., Henry, J., Hernandez-Garcia, C., Higgins, S., Higinbotham, D., Hofler, A. S., Hiatt, T., Hogan, J., Hovater, C., Hutton, A., Jones, C., Jordan, K., Joyce, M., Kazimi, R., Keesee, M., Kelley, M. J., Keppel, C., Kimber, A., King, L., Kjeldsen, P., Kneisel, P., Koval, J., Krafft, G. A., Lahti, G., Larrieu, T., Lauze, R., Leemann, C., Legg, R., Li, R., Lin, F., Machie, D., Mammosser, J., Macha, K., Mahoney, K., Marhauser, F., Mastracci, B., Matalevich, J., McCarter, J., McCaughan, M., Merminga, L., Michaud, R., Morozov, V., Mounts, C., Musson, J., Nelson, R., Oren, W., Overton, R. B., Palacios-Serrano, G., Park, H. -K., Phillips, L., Philip, S., Pilat, F., Plawski, T., Poelker, M., Powers, P., Powers, T., Preble, J., Reilly, T., Rimmer, R., Reece, C., Robertson, H., Roblin, Y., Rode, C., Satogata, T., Seidman, D. J., Seryi, A., Shabalina, A., Shin, I., Slominski, R., Slominski, C., Spata, M., Spell, D., Spradlin, J., Stirbet, M., Stutzman, M. L., Suhring, S., Surles-Law, K., Suleiman, R., Tennant, C., Tian, H., Turner, D., Tiefenback, M., Trofimova, O., Valente, A. -M., Wang, H., Wang, Y., White, K., Whitlatch, C., Whitlatch, T., Wiseman, M., Wissman, M. J., Wu, G., Yang, S., Yunn, B., Zhang, S., and Zhang, Y.

Subjects
Physics - Accelerator Physics, Nuclear Experiment
Abstract

This review paper describes the energy-upgraded CEBAF accelerator. This superconducting linac has achieved 12 GeV beam energy by adding 11 new high-performance cryomodules containing eighty-eight superconducting cavities that have operated CW at an average accelerating gradient of 20 MV/m. After reviewing the attributes and performance of the previous 6 GeV CEBAF accelerator, we discuss the upgraded CEBAF accelerator system in detail with particular attention paid to the new beam acceleration systems. In addition to doubling the acceleration in each linac, the upgrade included improving the beam recirculation magnets, adding more helium cooling capacity to allow the newly installed modules to run cold, adding a new experimental hall, and improving numerous other accelerator components. We review several of the techniques deployed to operate and analyze the accelerator performance, and document system operating experience and performance. In the final portion of the document, we present much of the current planning regarding projects to improve accelerator performance and enhance operating margins, and our plans for ensuring CEBAF operates reliably into the future. For the benefit of potential users of CEBAF, the performance and quality measures for beam delivered to each of the experimental halls is summarized in the appendix., Comment: 66 pages, 73 figures, 21 tables

Published
2024
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4. High-resolution assessment of riverbank erosion and stabilization techniques with associated water quality implications.

Author

Hayes, E., Higgins, S., Mullan, D., and Geris, J.

Subjects
*SUSPENDED sediments, *RELATIONSHIP quality, *GEOGRAPHIC information systems, *WATER quality, *RIPARIAN areas
Abstract

Agriculture is a key contributor to poor water quality, but the sources of sediment and nutrient losses from agricultural catchments – including from riverbank erosion – are highly variable. Riverbank erosion is particularly difficult to quantify and control. Here, we developed a quick assessment approach to quantify riverbank erosion rates and associated sediment and nutrient loading rates into waterways using airborne LiDAR combined with field-collected data. We applied this approach and explored its relationships to water quality at four sites within the Blackwater catchment in Northern Ireland for two analysis periods. GIS LiDAR image differencing revealed that volume changes in riverbank elevation equated to average erosion rates which indicated spatial and temporal variability in erosion rates. Combining the erosion rates with in-situ riverbank bulk density and total extractable phosphorus content provided sediment and phosphorus loading rates. The relative differences between estimated erosion at the different sites corresponded well with in-stream suspended sediment variations, but patterns for total phosphorus concentrations were more complex. We conclude that the use of LiDAR combined with field data is an innovative means for riverbank erosion quantification. Furthermore, by using LiDAR-to-LiDAR analyses, the reductions in erosion, sediment, and phosphorus loading rates following riverbank stabilization techniques can be determined. [ABSTRACT FROM AUTHOR]

Published
2024
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9. Non-matching predictions from different models simulating the effects of elevated atmospheric CO2 on the Amazon forest’s functional diversity

Author

Blanco, C.C., Rius, B.F., Darela-Filho, J.P., Cardeli, B., Aleixo, I., Scheiter, S., Langan, L., Joshi, J., Hofhansl, F., Singh, S., De Paula, M.D., Hickler, T., Ongole, S., Higgins, S., Fleischer, K., Rammig, A., Lichstein, J., Lapola, D.M., Blanco, C.C., Rius, B.F., Darela-Filho, J.P., Cardeli, B., Aleixo, I., Scheiter, S., Langan, L., Joshi, J., Hofhansl, F., Singh, S., De Paula, M.D., Hickler, T., Ongole, S., Higgins, S., Fleischer, K., Rammig, A., Lichstein, J., and Lapola, D.M.

Abstract

The continuous rising of atmospheric carbon dioxide (CO2) concentration is undoubtedly affecting the resilience of tropical forests worldwide. However, the magnitude of such effects is poorly known, limiting our capacity to assess the vulnerability of tropical forests and to improve their representation by models. Functional diversity (FD) is an important component of biodiversity enhancing ecosystem resilience, as high FD can provide higher response diversity and capacity to buffer against climate change. How FD is represented by different Dynamic Global Vegetation Models (DGVMs) may affect how such models predict the impacts of environmental changes on hyperdiverse ecosystems. We compared simulations of five trait-based DGVMs (i.e., with flexible, variable traits) constrained with data from the Amazon rainforest in the scope of the AmazonFACE project. Simulations were conducted considering initial high or low diversity scenarios under ambient and elevated CO2 (400 ppm and 600 ppm, respectively). We searched for correspondence between the functional identity of simulated plant strategies and their ecophysiological performances under elevated CO2. As models take different approaches to simulating functional trait distributions and they differ in their structure and in the trade-offs implemented, we found important intermodel differences in simulated results. Nevertheless, we took advantage of these differences in order to assess the most likely scenarios in terms of functional composition under elevated CO2, as well as to give feedback for better harmonization of model inputs and outputs and future model improvements. In the face of the pessimistic scenarios that project a continuous increase in CO2 levels, resolving the divergent responses among model predictions is critical, given the global importance of the Amazon rainforest's biodiversity and climate regulation, as well as the approximately 30 million people that directly or indirectly depend on the forest for

Published
2024
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10. Effects of asymmetric contacts on single molecule conductances of HS(CH2)nCOOH in nano-electrical junctions

Author

Martin, S., Manrique, D., Garcia-Suarez, V. M., Haiss, W., Higgins, S. J., Lambert, C. J., and Nichols, R. J.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

A scanning tunnelling microscope has been used to determine the conductance of single molecular wires with the configuration X-bridge-X, X-bridge-Y and Y-bridge-Y (X = thiol terminus and Y = COOH). We find that for molecular wires with mixed functional groups (X-bridge-Y) the single molecule conductance decreases with respect to the comparable symmetric molecules. These differences are confirmed by theoretical computations based on a combination of density functional theory and the non-equilibrium Green functions formalism. This study demonstrates that the apparent contact resistance, as well as being highly sensitive to the type of the anchoring group is also strongly influenced by contact-asymmetry of the single molecular junction which in this case decreases the transmission. This highlights that contact asymmetry is a significant factor to be considered when evaluating nano-electrical junctions incorporating single molecules.

Published
2015

14. Structures Produced by the Collision of Extragalactic Jets with Dense Clouds

Author

Higgins, S. W., O'Brien, T. J., and Dunlop, J. S.

Subjects
Astrophysics, Physics - Computational Physics, Physics - Fluid Dynamics
Abstract

We have investigated how several parameters can affect the results of a collision between an extragalactic jet and a dense, intergalactic cloud, through a series of hydrodynamic simulations. Such collisions are often suggested to explain the distorted structures of some radio jets. However, theoretical studies of this mechanism are in conflict over whether it can actually reproduce the observations. The parameters are the Mach number, and the relative densities of the jet and the cloud to the ambient medium. Using a simple prescription we have produced synthetic radio images for comparison with observations. These show that a variety of structures may be produced from simple jet-cloud collisions. We illustrate this with a few examples, and examine the details in one case. In most cases we do not see a clear, sustained deflection. Lighter jets are completely disrupted. The most powerful jets produce a hotspot at the impact which outshines any jet emission and erode the cloud too quickly to develop a deflected arm. It appears that moderate Mach numbers and density contrasts are needed to produce bends in the radio structure. This explains the apparent conflict between theoretical studies, as conclusions were based on different values of these parameters. Shocks are produced in the ambient medium that might plausibly reproduce the observed alignment of the extended emission line regions with the radio axis., Comment: 21 pages, 11 figures. Submitted to MNRAS. Also available in html version at http://www.doc.mmu.ac.uk/STAFF/S.Higgins/jcmnpaper/jc_mn.html

Published
1999
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21. AB0773 IMPROVING ADHERENCE TO TREATMENT IN BEHÇET’S DISEASE - THE MULTI-STAKEHOLDER IMPACT_BD INTERNATIONAL STUDY

Author

Marinello, D., primary, Cam, E., additional, Di Cianni, F., additional, Forrest, L., additional, Fortune, F., additional, Hatemi, G., additional, Higgins, S., additional, Italiano, N., additional, Lorenzoni, V., additional, Mazzeschi, E., additional, Mahr, A., additional, Moots, R. J., additional, Palla, I., additional, Saadoun, D., additional, Salvarani, C., additional, Schirmer, M., additional, Sfikakis, P., additional, Takahashi, J., additional, Takeno, M., additional, Turchetti, G., additional, Van Laar, J., additional, West, R., additional, Yazici, H., additional, Yazici, Y., additional, Zeis, J., additional, and Talarico, R., additional

Published
2023
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24. A model intercomparison project to study the role of plant functional diversity in the response of tropical forests to drought

Author

Lichstein, J.W., Longo, M., Bereswill, S., Blanco, C.C., Bonal, D., Chave, J., Christoffersen, B.O'D, de Paula, M.D., Derroire, G., Fisher, R.A., Hickler, T., Higgins, S., Hiltner, U., Hofhansl, F., Hogan, J.A., Huth, A., Joshi, J., Knapp, N., Langan, L., Lapola, D., Marechaux, I., Martinez Cano, I., Ongole, S., Rau, E-P., Restrepo-Coupe, N., Sakschewski, B., Saleska, S., Scheiter, S., Stahl, C., Thonicke, K., Wirth, C., Lichstein, J.W., Longo, M., Bereswill, S., Blanco, C.C., Bonal, D., Chave, J., Christoffersen, B.O'D, de Paula, M.D., Derroire, G., Fisher, R.A., Hickler, T., Higgins, S., Hiltner, U., Hofhansl, F., Hogan, J.A., Huth, A., Joshi, J., Knapp, N., Langan, L., Lapola, D., Marechaux, I., Martinez Cano, I., Ongole, S., Rau, E-P., Restrepo-Coupe, N., Sakschewski, B., Saleska, S., Scheiter, S., Stahl, C., Thonicke, K., and Wirth, C.

Abstract

Uncertainty in how the land carbon (C) sink will change over time contributes to uncertainty in Earth system model (ESM) projections of climate change. Much of the land sink is thought to reside in old-growth tropical forests, but recent analyses suggest a diminishing C sink in these forests due to rising temperatures and drought. Thus, there is an urgent need to better understand tropical forest responses to drought and to incorporate this understanding into ESMs. Previous work with vegetation demographic models (VDMs) – which represent the dynamics of individuals or cohorts, along with hydrology and biogeochemistry − suggest that functional diversity can enhance tropical forest resilience to climate change. However, there is little understanding of how different approaches to representing trait diversity and demography affect model outcomes. To explore the potential for trait diversity to moderate tropical forest responses to drought, we explored the behavior of nine VDMs, ranging from models with detailed site-level parameterizations to more generalized land models designed as ESM components. The behavior of each model was studied using soil and meteorological data collected at each of two tropical forest sites: Paracou Research Station, French Guiana, and Tapajos National Forest, Brazil. Low and high trait-diversity scenarios were simulated for each model using historical meteorology, as well as reduced rainfall scenarios. Few models showed strong effects of trait diversity on drought resistance (short-term response of forest biomass to rainfall reduction), but most models showed positive effects of diversity on resilience (long-term recovery of forest biomass following the initial biomass loss due to rainfall reduction). Long-term recovery was always associated with shifts in community composition towards greater drought-tolerance. However, there were large differences among models in the degree and time-scale of recovery. These differences were unrelated to th

Published
2023

25. Need for harmonized long-term multi-lake monitoring of African Great Lakes

Author

Plisnier, P. D. Kayanda, R. MacIntyre, S. Obiero, K. Okello, W. Vodacek, A. Cocquyt, C. Abegaz, H. Achieng, A. Akonkwa, B. Albrecht, C. Balagizi, C. Barasa, J. Abel Bashonga, R. Bashonga Bishobibiri, A. Bootsma, H. Borges, A. V. Chavula, G. Dadi, T. De Keyzer, E. L. R. Doran, P. J. Gabagambi, N. Gatare, R. Gemmell, A. Getahun, A. Haambiya, L. H. Higgins, S. N. Hyangya, B. L. Irvine, K. Isumbisho, M. Jonasse, C. Katongo, C. Katsev, S. Keyombe, J. Kimirei, I. Kisekelwa, T. Kishe, M. Otoung A. Koding, S. Kolding, J. Kraemer, B. M. Limbu, P. Lomodei, E. Mahongo, S. B. Malala, J. Mbabazi, S. Masilya, P. M. McCandless, M. Medard, M. Migeni Ajode, Z. Mrosso, H. D. Mudakikwa, E. R. Mulimbwa, N. Mushagalusa, D. Muvundja, F. A. Nankabirwa, A. Nahimana, D. Ngatunga, B. P. Ngochera, M. Nicholson, S. Nshombo, M. Ntakimazi, G. Nyamweya, C. Ikwaput Nyeko, J. Olago, D. Olbamo, T. O'Reilly, C. M. Pasche, N. Phiri, H. Raasakka, N. Salyani, A. Sibomana, C. Silsbe, G. M. Smith, S. Sterner, R. W. Thiery, W. Tuyisenge, J. Van der Knaap, M. Van Steenberge, M. van Zwieten, P. A. M. Verheyen, E. Wakjira, M. Walakira, J. Ndeo Wembo, O. Lawrence, T. and Plisnier, P. D. Kayanda, R. MacIntyre, S. Obiero, K. Okello, W. Vodacek, A. Cocquyt, C. Abegaz, H. Achieng, A. Akonkwa, B. Albrecht, C. Balagizi, C. Barasa, J. Abel Bashonga, R. Bashonga Bishobibiri, A. Bootsma, H. Borges, A. V. Chavula, G. Dadi, T. De Keyzer, E. L. R. Doran, P. J. Gabagambi, N. Gatare, R. Gemmell, A. Getahun, A. Haambiya, L. H. Higgins, S. N. Hyangya, B. L. Irvine, K. Isumbisho, M. Jonasse, C. Katongo, C. Katsev, S. Keyombe, J. Kimirei, I. Kisekelwa, T. Kishe, M. Otoung A. Koding, S. Kolding, J. Kraemer, B. M. Limbu, P. Lomodei, E. Mahongo, S. B. Malala, J. Mbabazi, S. Masilya, P. M. McCandless, M. Medard, M. Migeni Ajode, Z. Mrosso, H. D. Mudakikwa, E. R. Mulimbwa, N. Mushagalusa, D. Muvundja, F. A. Nankabirwa, A. Nahimana, D. Ngatunga, B. P. Ngochera, M. Nicholson, S. Nshombo, M. Ntakimazi, G. Nyamweya, C. Ikwaput Nyeko, J. Olago, D. Olbamo, T. O'Reilly, C. M. Pasche, N. Phiri, H. Raasakka, N. Salyani, A. Sibomana, C. Silsbe, G. M. Smith, S. Sterner, R. W. Thiery, W. Tuyisenge, J. Van der Knaap, M. Van Steenberge, M. van Zwieten, P. A. M. Verheyen, E. Wakjira, M. Walakira, J. Ndeo Wembo, O. Lawrence, T.

Abstract

To ensure the long-term sustainable use of African Great Lakes (AGL), and to better understand the functioning of these ecosystems, authorities, managers and scientists need regularly collected scientific data and information of key environmental indicators over multi-years to make informed decisions. Monitoring is regularly conducted at some sites across AGL; while at others sites, it is rare or conducted irregularly in response to sporadic funding or short-term projects/studies. Managers and scientists working on the AGL thus often lack critical long-term data to evaluate and gauge ongoing changes. Hence, we propose a multi-lake approach to harmonize data collection modalities for better understanding of regional and global environmental impacts on AGL. Climate variability has had strong impacts on all AGL in the recent past. Although these lakes have specific characteristics, their limnological cycles show many similarities. Because different anthropogenic pressures take place at the different AGL, harmonized multi-lake monitoring will provide comparable data to address the main drivers of concern (climate versus regional anthropogenic impact). To realize harmonized long-term multi-lake monitoring, the approach will need: (1) support of a wide community of researchers and managers; (2) political goodwill towards a common goal for such monitoring; and (3) sufficient capacity (e.g., institutional, financial, human and logistic resources) for its implementation. This paper presents an assessment of the state of monitoring the AGL and possible approaches to realize a long-term, multi-lake harmonized monitoring strategy. Key parameters are proposed. The support of national and regional authorities is necessary as each AGL crosses international boundaries.

Published
2023
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36. Creating Joint Representations of Collaborative Problem Solving with Multi-Touch Technology

Author

Mercier, E. and Higgins, S.

Abstract

Multi-touch surfaces have the potential to change the nature of computer-supported collaborative learning, allowing more equitable access to shared digital content. In this paper, we explore how large multi-touch tables can be used by groups of students as an external representation of their group interaction processes. Video data from 24 groups of students working on a logic reasoning problem was examined to identify their levels of reasoning about the task, and how they used the table to support their reasoning. Results indicate that of the 13 groups who solved or nearly solved the problem, 12 used the table to represent their reasoning process, while only four groups who used the table to support their reasoning process did not solve the problem. Examples from three groups are used to explore the different ways the table was used as an external representation of the groups' processes. The findings indicate that the group problem-solving process can be enhanced with the use of multi-touch tables, although students may need support in using the technology effectively to support their collaborative reasoning.

Published
2014
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38. The lack of Ambulation in REM sleep Behaviour disorder - Why do they stay in bed?

Author

Wasserman, D., primary, Gullone, S., additional, Duncan, I., additional, Veronese, M., additional, Gnoni, V., additional, Higgins, S., additional, Birdseye, A., additional, Gelegen, E. Cigdem, additional, Goadsby, P.J., additional, Ashkan, K., additional, Chaudhuri, K.R., additional, Tononi, G., additional, Drakatos, P., additional, and Rosenzweig, I., additional

Published
2022
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40. Global data set of long-term summertime vertical temperature profiles in 153 lakes

Author

Pilla, R, Mette, E, Williamson, C, Adamovich, B, Adrian, R, Anneville, O, Balseiro, E, Ban, S, Chandra, S, Colom-Montero, W, Devlin, S, Dix, M, Dokulil, M, Feldsine, N, Feuchtmayr, H, Fogarty, N, Gaiser, E, Girdner, S, Gonzalez, M, Hambright, K, Hamilton, D, Havens, K, Hessen, D, Hetzenauer, H, Higgins, S, Huttula, T, Huuskonen, H, Isles, P, Joehnk, K, Keller, W, Klug, J, Knoll, L, Korhonen, J, Korovchinsky, N, Koster, O, Kraemer, B, Leavitt, P, Leoni, B, Lepori, F, Lepskaya, E, Lottig, N, Luger, M, Maberly, S, Macintyre, S, Mcbride, C, Mcintyre, P, Melles, S, Modenutti, B, Muller-Navarra, D, Pacholski, L, Paterson, A, Pierson, D, Pislegina, H, Plisnier, P, Richardson, D, Rimmer, A, Rogora, M, Rogozin, D, Rusak, J, Rusanovskaya, O, Sadro, S, Salmaso, N, Saros, J, Sarvala, J, Saulnier-Talbot, E, Schindler, D, Shimaraeva, S, Silow, E, Sitoki, L, Sommaruga, R, Straile, D, Strock, K, Swain, H, Tallant, J, Thiery, W, Timofeyev, M, Tolomeev, A, Tominaga, K, Vanni, M, Verburg, P, Vinebrooke, R, Wanzenbock, J, Weathers, K, Weyhenmeyer, G, Zadereev, E, Zhukova, T, Pilla R. M., Mette E. M., Williamson C. E., Adamovich B. V., Adrian R., Anneville O., Balseiro E., Ban S., Chandra S., Colom-Montero W., Devlin S. P., Dix M. A., Dokulil M. T., Feldsine N. A., Feuchtmayr H., Fogarty N. K., Gaiser E. E., Girdner S. F., Gonzalez M. J., Hambright K. D., Hamilton D. P., Havens K., Hessen D. O., Hetzenauer H., Higgins S. N., Huttula T. H., Huuskonen H., Isles P. D. F., Joehnk K. D., Keller W. B., Klug J., Knoll L. B., Korhonen J., Korovchinsky N. M., Koster O., Kraemer B. M., Leavitt P. R., Leoni B., Lepori F., Lepskaya E. V., Lottig N. R., Luger M. S., Maberly S. C., MacIntyre S., McBride C., McIntyre P., Melles S. J., Modenutti B., Muller-Navarra D. C., Pacholski L., Paterson A. M., Pierson D. C., Pislegina H. V., Plisnier P. -D., Richardson D. C., Rimmer A., Rogora M., Rogozin D. Y., Rusak J. A., Rusanovskaya O. O., Sadro S., Salmaso N., Saros J. E., Sarvala J., Saulnier-Talbot E., Schindler D. E., Shimaraeva S. V., Silow E. A., Sitoki L. M., Sommaruga R., Straile D., Strock K. E., Swain H., Tallant J. M., Thiery W., Timofeyev M. A., Tolomeev A. P., Tominaga K., Vanni M. J., Verburg P., Vinebrooke R. D., Wanzenbock J., Weathers K., Weyhenmeyer G. A., Zadereev E. S., Zhukova T. V., Pilla, R, Mette, E, Williamson, C, Adamovich, B, Adrian, R, Anneville, O, Balseiro, E, Ban, S, Chandra, S, Colom-Montero, W, Devlin, S, Dix, M, Dokulil, M, Feldsine, N, Feuchtmayr, H, Fogarty, N, Gaiser, E, Girdner, S, Gonzalez, M, Hambright, K, Hamilton, D, Havens, K, Hessen, D, Hetzenauer, H, Higgins, S, Huttula, T, Huuskonen, H, Isles, P, Joehnk, K, Keller, W, Klug, J, Knoll, L, Korhonen, J, Korovchinsky, N, Koster, O, Kraemer, B, Leavitt, P, Leoni, B, Lepori, F, Lepskaya, E, Lottig, N, Luger, M, Maberly, S, Macintyre, S, Mcbride, C, Mcintyre, P, Melles, S, Modenutti, B, Muller-Navarra, D, Pacholski, L, Paterson, A, Pierson, D, Pislegina, H, Plisnier, P, Richardson, D, Rimmer, A, Rogora, M, Rogozin, D, Rusak, J, Rusanovskaya, O, Sadro, S, Salmaso, N, Saros, J, Sarvala, J, Saulnier-Talbot, E, Schindler, D, Shimaraeva, S, Silow, E, Sitoki, L, Sommaruga, R, Straile, D, Strock, K, Swain, H, Tallant, J, Thiery, W, Timofeyev, M, Tolomeev, A, Tominaga, K, Vanni, M, Verburg, P, Vinebrooke, R, Wanzenbock, J, Weathers, K, Weyhenmeyer, G, Zadereev, E, Zhukova, T, Pilla R. M., Mette E. M., Williamson C. E., Adamovich B. V., Adrian R., Anneville O., Balseiro E., Ban S., Chandra S., Colom-Montero W., Devlin S. P., Dix M. A., Dokulil M. T., Feldsine N. A., Feuchtmayr H., Fogarty N. K., Gaiser E. E., Girdner S. F., Gonzalez M. J., Hambright K. D., Hamilton D. P., Havens K., Hessen D. O., Hetzenauer H., Higgins S. N., Huttula T. H., Huuskonen H., Isles P. D. F., Joehnk K. D., Keller W. B., Klug J., Knoll L. B., Korhonen J., Korovchinsky N. M., Koster O., Kraemer B. M., Leavitt P. R., Leoni B., Lepori F., Lepskaya E. V., Lottig N. R., Luger M. S., Maberly S. C., MacIntyre S., McBride C., McIntyre P., Melles S. J., Modenutti B., Muller-Navarra D. C., Pacholski L., Paterson A. M., Pierson D. C., Pislegina H. V., Plisnier P. -D., Richardson D. C., Rimmer A., Rogora M., Rogozin D. Y., Rusak J. A., Rusanovskaya O. O., Sadro S., Salmaso N., Saros J. E., Sarvala J., Saulnier-Talbot E., Schindler D. E., Shimaraeva S. V., Silow E. A., Sitoki L. M., Sommaruga R., Straile D., Strock K. E., Swain H., Tallant J. M., Thiery W., Timofeyev M. A., Tolomeev A. P., Tominaga K., Vanni M. J., Verburg P., Vinebrooke R. D., Wanzenbock J., Weathers K., Weyhenmeyer G. A., Zadereev E. S., and Zhukova T. V.

Abstract

Climate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change.

Published
2021

42. Effects of Traditional, Blended and E-Learning on Students' Achievement in Higher Education

Author

Al-Qahtani, Awadh A. Y. and Higgins, S. E.

Abstract

The study investigates the effect of e-learning, blended learning and classroom learning on students' achievement. Two experimental groups together with a control group from Umm Al-Qura University in Saudi Arabia were identified randomly. To assess students' achievement in the different groups, pre- and post-achievement tests were used. The results of the study ("N"?=?148) show that there was a statistically significant difference between the three methods in terms of students' achievement favouring the blended learning method ("n"?=?55) with a substantial effect size of 1.34 (Hedges' g). No significant difference was found between the e-learning ("n"?=?43) and traditional learning groups ("n"?=?50) in terms of students' achievement and with a negligible effect size of 0.02. (Contains 3 tables.)

Published
2013
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46. Wellness 101: Health Education for the University Student

Author

Higgins, S. Joan Wharf, Lauzon, Lara L., Yew, Ann C., Bratseth, Christopher D., and McLeod, Nicole

Abstract

Purpose: This paper aims to describe two phases of a mixed-method study: in phase I, the wellness practices of students at a Canadian university are reported. These data informed the re-development of a first-year health education course. Subsequent to its revision, phase II of the study assessed the impact of the course on students' wellness practices and learnings. Design/methodology/approach: In phase I, 855 students completed a survey rating ten wellness practices relating to themselves. Survey results were explored further in focus groups with 60 students. In phase II, a pre- and post-design assessed the impact of the health education curriculum. Wellness practices were surveyed, at the beginning and end of term, and content analysis was conducted on students' assignments. Findings: In phase I, the mean overall wellness score was 779.7 out of 1,000 or "good". Students scored highest in sexuality and safety, and lowest in physical activity and nutrition. Qualitative analyses revealed four primary themes important to students' wellness: being or holistic health; belonging or feeling connected to others and the campus; becoming or studying to achieve a professional or scholarly degree; and balance--or the search for stability. In phase II, significant changes were found for seven wellness scores when comparing the beginning and end of semester. Analysis of course assignments found that students left the course with enhanced affect and knowledge levels. Originality/value: The results support the argument that a health education curriculum, responsive to students' identified needs, and in conjunction with a healthy campus environment, promises to enhance student wellness. (Contains 6 tables and 1 figure.)

Published
2010
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48. Tallo: A global tree allometry and crown architecture database

Author

Jucker, T., Fischer, F. J., Chave, J., Coomes, D. A., Caspersen, J., Ali, A., Loubota, Panzou, G. J., Feldpausch, T. R., Falster, D., Usoltsev, V. A., Adu-Bredu, S., Alves, L. F., Aminpour, M., Angoboy, I. B., Anten, N. P. R., Antin, C., Askari, Y., Muñoz, R., Ayyappan, N., Balvanera, P., Banin, L., Barbier, N., Battles, J. J., Beeckman, H., Bocko, Y. E., Bond-Lamberty, B., Bongers, F., Bowers, S., Brade, T., van, Breugel, M., Chantrain, A., Chaudhary, R., Dai, J., Dalponte, M., Dimobe, K., Domec, J. -C., Doucet, J. -L., Duursma, R. A., Enríquez, M., van, Ewijk, K. Y., Farfán-Rios, W., Fayolle, A., Forni, E., Forrester, D. I., Gilani, H., Godlee, J. L., Gourlet-Fleury, S., Haeni, M., Hall, J. S., He, J. -K., Hemp, A., Hernández-Stefanoni, J. L., Higgins, S. I., Holdaway, R. J., Hussain, K., Hutley, L. B., Ichie, T., Iida, Y., Jiang, H. -S., Joshi, P. R., Kaboli, H., Larsary, M. K., Kenzo, T., Kloeppel, B. D., Kohyama, T., Kunwar, S., Kuyah, S., Kvasnica, J., Lin, S., Lines, E. R., Liu, H., Lorimer, C., Loumeto, J. -J., Malhi, Y., Marshall, P. L., Mattsson, E., Matula, R., Meave, J. A., Mensah, S., Mi, X., Momo, S., Moncrieff, G. R., Mora, F., Nissanka, S. P., O'Hara, K. L., Pearce, S., Pelissier, R., Peri, P. L., Ploton, P., Poorter, L., Pour, M. J., Pourbabaei, H., Dupuy-Rada, J. M., Ribeiro, S. C., Ryan, C., Sanaei, A., Sanger, J., Schlund, M., Sellan, G., Shenkin, A., Sonké, B., Sterck, F. J., Svátek, M., Takagi, K., Trugman, A. T., Ullah, F., Vadeboncoeur, M. A., Valipour, A., Vanderwel, M. C., Vovides, A. G., Wang, W., Wang, L. -Q., Wirth, C., Woods, M., Xiang, W., Ximenes, F. D. A., Xu, Y., Yamada, T., Zavala, M. A., Jucker, T., Fischer, F. J., Chave, J., Coomes, D. A., Caspersen, J., Ali, A., Loubota, Panzou, G. J., Feldpausch, T. R., Falster, D., Usoltsev, V. A., Adu-Bredu, S., Alves, L. F., Aminpour, M., Angoboy, I. B., Anten, N. P. R., Antin, C., Askari, Y., Muñoz, R., Ayyappan, N., Balvanera, P., Banin, L., Barbier, N., Battles, J. J., Beeckman, H., Bocko, Y. E., Bond-Lamberty, B., Bongers, F., Bowers, S., Brade, T., van, Breugel, M., Chantrain, A., Chaudhary, R., Dai, J., Dalponte, M., Dimobe, K., Domec, J. -C., Doucet, J. -L., Duursma, R. A., Enríquez, M., van, Ewijk, K. Y., Farfán-Rios, W., Fayolle, A., Forni, E., Forrester, D. I., Gilani, H., Godlee, J. L., Gourlet-Fleury, S., Haeni, M., Hall, J. S., He, J. -K., Hemp, A., Hernández-Stefanoni, J. L., Higgins, S. I., Holdaway, R. J., Hussain, K., Hutley, L. B., Ichie, T., Iida, Y., Jiang, H. -S., Joshi, P. R., Kaboli, H., Larsary, M. K., Kenzo, T., Kloeppel, B. D., Kohyama, T., Kunwar, S., Kuyah, S., Kvasnica, J., Lin, S., Lines, E. R., Liu, H., Lorimer, C., Loumeto, J. -J., Malhi, Y., Marshall, P. L., Mattsson, E., Matula, R., Meave, J. A., Mensah, S., Mi, X., Momo, S., Moncrieff, G. R., Mora, F., Nissanka, S. P., O'Hara, K. L., Pearce, S., Pelissier, R., Peri, P. L., Ploton, P., Poorter, L., Pour, M. J., Pourbabaei, H., Dupuy-Rada, J. M., Ribeiro, S. C., Ryan, C., Sanaei, A., Sanger, J., Schlund, M., Sellan, G., Shenkin, A., Sonké, B., Sterck, F. J., Svátek, M., Takagi, K., Trugman, A. T., Ullah, F., Vadeboncoeur, M. A., Valipour, A., Vanderwel, M. C., Vovides, A. G., Wang, W., Wang, L. -Q., Wirth, C., Woods, M., Xiang, W., Ximenes, F. D. A., Xu, Y., Yamada, T., and Zavala, M. A.

Abstract

Data capturing multiple axes of tree size and shape, such as a tree's stem diameter, height and crown size, underpin a wide range of ecological research—from developing and testing theory on forest structure and dynamics, to estimating forest carbon stocks and their uncertainties, and integrating remote sensing imagery into forest monitoring programmes. However, these data can be surprisingly hard to come by, particularly for certain regions of the world and for specific taxonomic groups, posing a real barrier to progress in these fields. To overcome this challenge, we developed the Tallo database, a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. These data were collected at 61,856 globally distributed sites, spanning all major forested and non-forested biomes. The majority of trees in the database are identified to species (88%), and collectively Tallo includes data for 5163 species distributed across 1453 genera and 187 plant families. The database is publicly archived under a CC-BY 4.0 licence and can be access from: https://doi.org/10.5281/zenodo.6637599. To demonstrate its value, here we present three case studies that highlight how the Tallo database can be used to address a range of theoretical and applied questions in ecology—from testing the predictions of metabolic scaling theory, to exploring the limits of tree allometric plasticity along environmental gradients and modelling global variation in maximum attainable tree height. In doing so, we provide a key resource for field ecologists, remote sensing researchers and the modelling community working together to better understand the role that trees play in regulating the terrestrial carbon cycle. © 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.

Published
2022

49. Comparison of Nitrogen Fertiliser recommendations in different West European countries

Author

UCL - SST/ELI/ELIA - Agronomy, Jordan-Meille, L, Higgins, S., Dittert, K., Cugnon, Thibault, UCL - SST/ELI/ELIA - Agronomy, Jordan-Meille, L, Higgins, S., Dittert, K., and Cugnon, Thibault

Abstract

Nitrogen (N) budget at farm level is influenced by the fertilisation rates applied by farmers. At larger scales, it is closely linked to multiple environmental concerns relating to air, water and biodiversity. In this study, we analysed the way the N fertilisation recommendations are calculated in ten West European countries, in order to detect innovative algorithms, original calculations and references that could be shared among countries having equivalent crop practices. Our first result relates to published national official documents governing N fertilisation within each country. A detailed analysis of these documents reveals three categories of calculation methods: (i) ‘N mass balance’ (France, Italy, Spain), (ii) ‘Corrected standard’ (Germany, the Netherlands, Switzerland, Luxembourg), and (iii) ‘Pre-parameterised calculation’, relying on a soil N supply typology (United Kingdom, Ireland) or on a model parameterisation (Belgium). Sixteen parameters were identified throughout the 10 national methods. The more complex algorithms use 10 parameters (Italy, France), while the simplest only rely on 3 (Luxembourg). The most common parameters considered include the direct effect of N concentration in manure, the total N uptake by crop and the N released by crop residues. At the opposite end, very few countries explicitly take N leaching, the residual mineral N in soil at harvest and atmospheric losses into consideration. In addition to the previous theoretical approach, we have tested the extent to which the different methods converge or not when practically used. We therefore applied the ten national methods to two contrasting crop scenarios chosen in order to erase as much as possible the cultural and pedoclimatic specificities between the ten countries. The two case studies display large discrepancies in their recommendations, ranging from no fertilisation to 135 kg N/ha, and from 111 to 210 kg N/ha for a wheat crop fertilisation grown in a livestock and polycultur

Published
2022

50. Global patterns and controls of nutrient immobilization on decomposing cellulose in riverine ecosystems

Author

Costello, D. M. (David M.), Tiegs, S. D. (Scott D.), Boyero, L. (Luz), Canhoto, C. (Cristina), Capps, K. A. (Krista A.), Danger, M. (Michael), Frost, P. C. (Paul C.), Gessner, M. O. (Mark O.), Griffiths, N. A. (Natalie A.), Halvorson, H. M. (Halvor M.), Kuehn, K. A. (Kevin A.), Marcarelli, A. M. (Amy M.), Royer, T. V. (Todd, V), Mathie, D. M. (Devan M.), Albarino, R. J. (Ricardo J.), Arango, C. P. (Clay P.), Aroviita, J. (Jukka), Baxter, C. V. (Colden, V), Bellinger, B. J. (Brent J.), Bruder, A. (Andreas), Burdon, F. J. (Francis J.), Callisto, M. (Marcos), Camacho, A. (Antonio), Colas, F. (Fanny), Cornut, J. (Julien), Crespo-Perez, V. (Veronica), Cross, W. F. (Wyatt F.), Derry, A. M. (Alison M.), Douglas, M. M. (Michael M.), Elosegi, A. (Arturo), Eyto, E. (Elvira), Ferreira, V. (Veronica), Ferriol, C. (Carmen), Fleituch, T. (Tadeusz), Shah, J. J. (Jennifer J. Follstad), Frainer, A. (Andre), Garcia, E. A. (Erica A.), Garcia, L. (Liliana), Garcia, P. E. (Pavel E.), Giling, D. P. (Darren P.), Gonzales-Pomar, R. K. (R. Karina), Graca, M. A. (Manuel A. S.), Grossart, H.-P. (Hans-Peter), Guerold, F. (Francois), Hepp, L. U. (Luiz U.), Higgins, S. N. (Scott N.), Hishi, T. (Takuo), Iniguez-Armijos, C. (Carlos), Iwata, T. (Tomoya), Kirkwood, A. E. (Andrea E.), Koning, A. A. (Aaron A.), Kosten, S. (Sarian), Laudon, H. (Hjalmar), Leavitt, P. R. (Peter R.), Lemes da Silva, A. L. (Aurea L.), Leroux, S. J. (Shawn J.), LeRoy, C. J. (Carri J.), Lisi, P. J. (Peter J.), Masese, F. O. (Frank O.), McIntyre, P. B. (Peter B.), McKie, B. G. (Brendan G.), Medeiros, A. O. (Adriana O.), Milisa, M. (Marko), Miyake, Y. (Yo), Mooney, R. J. (Robert J.), Muotka, T. (Timo), Nimptsch, J. (Jorge), Paavola, R. (Riku), Pardo, I. (Isabel), Parnikoza, I. Y. (Ivan Y.), Patrick, C. J. (Christopher J.), Peeters, E. T. (Edwin T. H. M.), Pozo, J. (Jesus), Reid, B. (Brian), Richardson, J. S. (John S.), Rincon, J. (Jose), Risnoveanu, G. (Geta), Robinson, C. T. (Christopher T.), Santamans, A. C. (Anna C.), Simiyu, G. M. (Gelas M.), Skuja, A. (Agnija), Smykla, J. (Jerzy), Sponseller, R. A. (Ryan A.), Teixeira-de Mello, F. (Franco), Vilbaste, S. (Sirje), Villanueva, V. D. (Veronica D.), Webster, J. R. (Jackson R.), Woelfl, S. (Stefan), Xenopoulos, M. A. (Marguerite A.), Yates, A. G. (Adam G.), Yule, C. M. (Catherine M.), Zhang, Y. (Yixin), Zwart, J. A. (Jacob A.), Costello, D. M. (David M.), Tiegs, S. D. (Scott D.), Boyero, L. (Luz), Canhoto, C. (Cristina), Capps, K. A. (Krista A.), Danger, M. (Michael), Frost, P. C. (Paul C.), Gessner, M. O. (Mark O.), Griffiths, N. A. (Natalie A.), Halvorson, H. M. (Halvor M.), Kuehn, K. A. (Kevin A.), Marcarelli, A. M. (Amy M.), Royer, T. V. (Todd, V), Mathie, D. M. (Devan M.), Albarino, R. J. (Ricardo J.), Arango, C. P. (Clay P.), Aroviita, J. (Jukka), Baxter, C. V. (Colden, V), Bellinger, B. J. (Brent J.), Bruder, A. (Andreas), Burdon, F. J. (Francis J.), Callisto, M. (Marcos), Camacho, A. (Antonio), Colas, F. (Fanny), Cornut, J. (Julien), Crespo-Perez, V. (Veronica), Cross, W. F. (Wyatt F.), Derry, A. M. (Alison M.), Douglas, M. M. (Michael M.), Elosegi, A. (Arturo), Eyto, E. (Elvira), Ferreira, V. (Veronica), Ferriol, C. (Carmen), Fleituch, T. (Tadeusz), Shah, J. J. (Jennifer J. Follstad), Frainer, A. (Andre), Garcia, E. A. (Erica A.), Garcia, L. (Liliana), Garcia, P. E. (Pavel E.), Giling, D. P. (Darren P.), Gonzales-Pomar, R. K. (R. Karina), Graca, M. A. (Manuel A. S.), Grossart, H.-P. (Hans-Peter), Guerold, F. (Francois), Hepp, L. U. (Luiz U.), Higgins, S. N. (Scott N.), Hishi, T. (Takuo), Iniguez-Armijos, C. (Carlos), Iwata, T. (Tomoya), Kirkwood, A. E. (Andrea E.), Koning, A. A. (Aaron A.), Kosten, S. (Sarian), Laudon, H. (Hjalmar), Leavitt, P. R. (Peter R.), Lemes da Silva, A. L. (Aurea L.), Leroux, S. J. (Shawn J.), LeRoy, C. J. (Carri J.), Lisi, P. J. (Peter J.), Masese, F. O. (Frank O.), McIntyre, P. B. (Peter B.), McKie, B. G. (Brendan G.), Medeiros, A. O. (Adriana O.), Milisa, M. (Marko), Miyake, Y. (Yo), Mooney, R. J. (Robert J.), Muotka, T. (Timo), Nimptsch, J. (Jorge), Paavola, R. (Riku), Pardo, I. (Isabel), Parnikoza, I. Y. (Ivan Y.), Patrick, C. J. (Christopher J.), Peeters, E. T. (Edwin T. H. M.), Pozo, J. (Jesus), Reid, B. (Brian), Richardson, J. S. (John S.), Rincon, J. (Jose), Risnoveanu, G. (Geta), Robinson, C. T. (Christopher T.), Santamans, A. C. (Anna C.), Simiyu, G. M. (Gelas M.), Skuja, A. (Agnija), Smykla, J. (Jerzy), Sponseller, R. A. (Ryan A.), Teixeira-de Mello, F. (Franco), Vilbaste, S. (Sirje), Villanueva, V. D. (Veronica D.), Webster, J. R. (Jackson R.), Woelfl, S. (Stefan), Xenopoulos, M. A. (Marguerite A.), Yates, A. G. (Adam G.), Yule, C. M. (Catherine M.), Zhang, Y. (Yixin), and Zwart, J. A. (Jacob A.)

Abstract

Microbes play a critical role in plant litter decomposition and influence the fate of carbon in rivers and riparian zones. When decomposing low-nutrient plant litter, microbes acquire nitrogen (N) and phosphorus (P) from the environment (i.e., nutrient immobilization), and this process is potentially sensitive to nutrient loading and changing climate. Nonetheless, environmental controls on immobilization are poorly understood because rates are also influenced by plant litter chemistry, which is coupled to the same environmental factors. Here we used a standardized, low-nutrient organic matter substrate (cotton strips) to quantify nutrient immobilization at 100 paired stream and riparian sites representing 11 biomes worldwide. Immobilization rates varied by three orders of magnitude, were greater in rivers than riparian zones, and were strongly correlated to decomposition rates. In rivers, P immobilization rates were controlled by surface water phosphate concentrations, but N immobilization rates were not related to inorganic N. The N:P of immobilized nutrients was tightly constrained to a molar ratio of 10:1 despite wide variation in surface water N:P. Immobilization rates were temperature-dependent in riparian zones but not related to temperature in rivers. However, in rivers nutrient supply ultimately controlled whether microbes could achieve the maximum expected decomposition rate at a given temperature. Collectively, we demonstrated that exogenous nutrient supply and immobilization are critical control points for decomposition of organic matter.

Published
2022

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