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1. Discovering Electric Vehicle Charging Locations Based on Clustering Techniques Applied to Vehicular Mobility Datasets

Author

Elmer Magsino, Francis Miguel M. Espiritu, and Kerwin D. Go

Subjects
clustering techniques, vehicular mobility datasets, silhouette and Calinski–Harabasz indices, spatiotemporal stable network characteristics, Geography (General), G1-922
Abstract

With the proliferation of vehicular mobility traces because of inexpensive on-board sensors and smartphones, utilizing them to further understand road movements have become easily accessible. These huge numbers of vehicular traces can be utilized to determine where to enhance road infrastructures such as the deployment of electric vehicle (EV) charging stations. As more EVs are plying today’s roads, the driving anxiety is minimized with the presence of sufficient charging stations. By correctly extracting the various transportation parameters from a given dataset, one can design an adequate and adaptive EV charging network that can provide comfort and convenience for the movement of people and goods from one point to another. In this study, we determined the possible EV charging station locations based on an urban city’s vehicular capacity distribution obtained from taxi and ride-hailing mobility GPS traces. To achieve this, we first transformed the dynamic vehicular environment based on vehicular capacity into its equivalent urban single snapshot. We then obtained the various traffic zone distributions by initially utilizing k-means clustering to allow flexibility in the total number of wanted traffic zones in each dataset. In each traffic zone, iterative clustering techniques employing Density-based Spatial Clustering of Applications with Noise (DBSCAN) or clustering by fast search and find of density peaks (CFS) revealed various area separation where EV chargers were needed. Finally, to find the exact location of the EV charging station, we last ran k-means to locate centroids, depending on the constraint on how many EV chargers were needed. Extensive simulations revealed the strengths and weaknesses of the clustering methods when applied to our datasets. We utilized the silhouette and Calinski–Harabasz indices to measure the validity of cluster formations. We also measured the inter-station distances to understand the closeness of the locations of EV chargers. Our study shows how CFS + k-means clustering techniques are able to pinpoint EV charger locations. However, when utilizing DBSCAN initially, the results did not present any notable outcome.

Published
2024
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2. Comparison of sporadic and familial behavioral variant frontotemporal dementia (FTD) in a North American cohort

Author

Heuer, Hilary W, Wang, P, Rascovsky, K, Wolf, A, Appleby, B, Bove, J, Bordelon, Y, Brannelly, P, Brushaber, DE, Caso, C, Coppola, G, Dickerson, B, Dickinson, S, Domoto‐Reilly, K, Faber, K, Ferrall, J, Fields, J, Fishman, A, Fong, J, Foroud, T, Forsberg, LK, Gearhart, D, Ghazanfari, B, Ghoshal, N, Goldman, J, Graff‐Radford, J, Graff‐Radford, N, Grant, I, Grossman, M, Haley, D, Hsiung, G‐Y, Huey, E, Irwin, D, Jones, D, Kantarci, K, Karydas, A, Kaufer, D, Kerwin, D, Knopman, D, Kornak, J, Kramer, JH, Kraft, R, Kremers, WK, Kukull, W, Litvan, I, Ljubenkov, P, Mackenzie, IR, Maldonado, M, Manoochehri, M, McGinnis, S, McKinley, E, Mendez, MF, Miller, BL, Onyike, C, Pantelyat, A, Pearlman, R, Petrucelli, L, Potter, M, Rademakers, R, Ramos, EM, Rankin, KP, Roberson, ED, Rogalski, E, Sengdy, P, Shaw, L, Syrjanen, J, Tartaglia, MC, Tatton, N, Taylor, J, Toga, A, Trojanowski, J, Weintraub, S, Wong, B, Wszolek, Z, Boeve, BF, Rosen, HJ, Boxer, AL, and consortia, on behalf of the ARTFL and LEFFTDS

Subjects
Biomedical and Clinical Sciences, Neurosciences, Clinical Sciences, Aging, Acquired Cognitive Impairment, Alzheimer's Disease Related Dementias (ADRD), Frontotemporal Dementia (FTD), Behavioral and Social Science, Genetics, Clinical Research, Dementia, Rare Diseases, Neurodegenerative, Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD), Brain Disorders, Neurological, Age Factors, Aged, Brain, C9orf72 Protein, Female, Frontotemporal Dementia, Genetic Predisposition to Disease, Humans, Male, Middle Aged, Mutation, Neuropsychological Tests, North America, Progranulins, tau Proteins, bvFTD, C9orf72, clinical trials, frontotemporal dementia, genetics, GRN, MAPT, ARTFL and LEFFTDS consortia, Geriatrics, Clinical sciences, Biological psychology
Abstract

IntroductionBehavioral variant frontotemporal dementia (bvFTD) may present sporadically or due to an autosomal dominant mutation. Characterization of both forms will improve understanding of the generalizability of assessments and treatments.MethodsA total of 135 sporadic (s-bvFTD; mean age 63.3 years; 34% female) and 99 familial (f-bvFTD; mean age 59.9; 48% female) bvFTD participants were identified. f-bvFTD cases included 43 with known or presumed chromosome 9 open reading frame 72 (C9orf72) gene expansions, 28 with known or presumed microtubule-associated protein tau (MAPT) mutations, 14 with known progranulin (GRN) mutations, and 14 with a strong family history of FTD but no identified mutation.ResultsParticipants with f-bvFTD were younger and had earlier age at onset. s-bvFTD had higher total Neuropsychiatric Inventory Questionnaire (NPI-Q) scores due to more frequent endorsement of depression and irritability.Discussionf-bvFTD and s-bvFTD cases are clinically similar, suggesting the generalizability of novel biomarkers, therapies, and clinical tools developed in either form to the other.

Published
2020

3. Active lifestyles moderate clinical outcomes in autosomal dominant frontotemporal degeneration

Author

Casaletto, KB, Staffaroni, AM, Wolf, A, Appleby, B, Brushaber, D, Coppola, G, Dickerson, B, Domoto‐Reilly, K, Elahi, FM, Fields, J, Fong, JC, Forsberg, L, Ghoshal, N, Graff‐Radford, N, Grossman, M, Heuer, HW, Hsiung, G‐Y, Huey, ED, Irwin, D, Kantarci, K, Kaufer, D, Kerwin, D, Knopman, D, Kornak, J, Kramer, JH, Litvan, I, Mackenzie, IR, Mendez, M, Miller, B, Rademakers, R, Ramos, EM, Rascovsky, K, Roberson, ED, Syrjanen, JA, Tartaglia, MC, Weintraub, S, Boeve, B, Boxer, AL, Rosen, H, Yaffe, K, and Study, the ARTFL LEFFTDS

Subjects
Biological Psychology, Biomedical and Clinical Sciences, Psychology, Alzheimer's Disease Related Dementias (ADRD), Alzheimer's Disease, Biomedical Imaging, Neurodegenerative, Neurosciences, Aging, Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD), Behavioral and Social Science, Rare Diseases, Dementia, Acquired Cognitive Impairment, Frontotemporal Dementia (FTD), Brain Disorders, Neurological, Aged, Atrophy, Cognition, Exercise, Female, Frontotemporal Lobar Degeneration, Humans, Leisure Activities, Longitudinal Studies, Magnetic Resonance Imaging, Male, Middle Aged, Neuropsychological Tests, cognitive activity, cognitive reserve, exercise, frontotemporal dementia, physical activity, ARTFL/LEFFTDS Study, Clinical Sciences, Geriatrics, Clinical sciences, Biological psychology
Abstract

IntroductionLeisure activities impact brain aging and may be prevention targets. We characterized how physical and cognitive activities relate to brain health for the first time in autosomal dominant frontotemporal lobar degeneration (FTLD).MethodsA total of 105 mutation carriers (C9orf72/MAPT/GRN) and 69 non-carriers reported current physical and cognitive activities at baseline, and completed longitudinal neurobehavioral assessments and brain magnetic resonance imaging (MRI) scans.ResultsGreater physical and cognitive activities were each associated with an estimated >55% slower clinical decline per year among dominant gene carriers. There was also an interaction between leisure activities and frontotemporal atrophy on cognition in mutation carriers. High-activity carriers with frontotemporal atrophy (-1 standard deviation/year) demonstrated >two-fold better cognitive performances per year compared to their less active peers with comparable atrophy rates.DiscussionActive lifestyles were associated with less functional decline and moderated brain-to-behavior relationships longitudinally. More active carriers "outperformed" brain volume, commensurate with a cognitive reserve hypothesis. Lifestyle may confer clinical resilience, even in autosomal dominant FTLD.

Published
2020

4. Discovering Electric Vehicle Charging Locations Based on Clustering Techniques Applied to Vehicular Mobility Datasets.

Author

Magsino, Elmer, Espiritu, Francis Miguel M., and Go, Kerwin D.

Subjects
ELECTRIC vehicle charging stations, K-means clustering, PHYSICAL distribution of goods, CENTROID, SMARTPHONES, ELECTRIC vehicles
Abstract

With the proliferation of vehicular mobility traces because of inexpensive on-board sensors and smartphones, utilizing them to further understand road movements have become easily accessible. These huge numbers of vehicular traces can be utilized to determine where to enhance road infrastructures such as the deployment of electric vehicle (EV) charging stations. As more EVs are plying today's roads, the driving anxiety is minimized with the presence of sufficient charging stations. By correctly extracting the various transportation parameters from a given dataset, one can design an adequate and adaptive EV charging network that can provide comfort and convenience for the movement of people and goods from one point to another. In this study, we determined the possible EV charging station locations based on an urban city's vehicular capacity distribution obtained from taxi and ride-hailing mobility GPS traces. To achieve this, we first transformed the dynamic vehicular environment based on vehicular capacity into its equivalent urban single snapshot. We then obtained the various traffic zone distributions by initially utilizing k-means clustering to allow flexibility in the total number of wanted traffic zones in each dataset. In each traffic zone, iterative clustering techniques employing Density-based Spatial Clustering of Applications with Noise (DBSCAN) or clustering by fast search and find of density peaks (CFS) revealed various area separation where EV chargers were needed. Finally, to find the exact location of the EV charging station, we last ran k-means to locate centroids, depending on the constraint on how many EV chargers were needed. Extensive simulations revealed the strengths and weaknesses of the clustering methods when applied to our datasets. We utilized the silhouette and Calinski–Harabasz indices to measure the validity of cluster formations. We also measured the inter-station distances to understand the closeness of the locations of EV chargers. Our study shows how CFS + k-means clustering techniques are able to pinpoint EV charger locations. However, when utilizing DBSCAN initially, the results did not present any notable outcome. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
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5. Prognostic relevance of gait-related cognitive functions for dementia conversion in amnestic mild cognitive impairment

Author

Tuena, C, Maestri, S, Serino, S, Pedroli, E, Stramba-Badiale, M, Riva, G, Silbert, L, Lind, B, Crissey, R, Kaye, J, Carter, R, Dolen, S, Quinn, J, Schneider, L, Pawluczyk, S, Becerra, M, Teodoro, L, Dagerman, K, Spann, B, Brewer, J, Fleisher, A, Vanderswag, H, Ziolkowski, J, Heidebrink, J, Zbizek-Nulph, L, Lord, J, Albers, C, Petersen, R, Mason, S, Knopman, D, Johnson, K, Villanueva-Meyer, J, Pavlik, V, Pacini, N, Lamb, A, Kass, J, Doody, R, Shibley, V, Chowdhury, M, Rountree, S, Dang, M, Stern, Y, Honig, L, Mintz, A, Ances, B, Morris, J, Winkfield, D, Carroll, M, Stobbs-Cucchi, G, Oliver, A, Creech, M, Mintun, M, Schneider, S, Geldmacher, D, Love, M, Griffith, R, Clark, D, Brockington, J, Marson, D, Grossman, H, Goldstein, M, Greenberg, J, Mitsis, E, Shah, R, Lamar, M, Samuels, P, Duara, R, Greig-Custo, M, Rodriguez, R, Albert, M, Onyike, C, Farrington, L, Rudow, S, Brichko, R, Kielb, S, Smith, A, Raj, B, Fargher, K, Sadowski, M, Wisniewski, T, Shulman, M, Faustin, A, Rao, J, Castro, K, Ulysse, A, Chen, S, Doraiswamy, P, Petrella, J, James, O, Wong, T, Borges-Neto, S, Karlawish, J, Wolk, D, Vaishnavi, S, Clark, C, Arnold, S, Smith, C, Jicha, G, Khouli, R, Raslau, F, Lopez, O, Oakley, M, Simpson, D, Porsteinsson, A, Martin, K, Kowalski, N, Keltz, M, Goldstein, B, Makino, K, Ismail, M, Brand, C, Thai, G, Pierce, A, Yanez, B, Sosa, E, Witbracht, M, Kelley, B, Nguyen, T, Womack, K, Mathews, D, Quiceno, M, Levey, A, Lah, J, Hajjar, I, Burns, J, Swerdlow, R, Brooks, W, Silverman, D, Kremen, S, Apostolova, L, Tingus, K, Lu, P, Bartzokis, G, Woo, E, Teng, E, Graff-Radford, N, Parfitt, F, Poki-Walker, K, Farlow, M, Hake, A, Matthews, B, Brosch, J, Herring, S, van Dyck, C, Mecca, A, Good, S, Macavoy, M, Carson, R, Varma, P, Chertkow, H, Vaitekunas, S, Hosein, C, Black, S, Stefanovic, B, Heyn, C, Hsiung, G, Kim, E, Mudge, B, Sossi, V, Feldman, H, Assaly, M, Finger, E, Pasternak, S, Rachinsky, I, Kertesz, A, Drost, D, Rogers, J, Grant, I, Muse, B, Rogalski, E, Robson, J, Mesulam, M, Kerwin, D, Wu, C, Johnson, N, Lipowski, K, Weintraub, S, Bonakdarpour, B, Pomara, N, Hernando, R, Sarrael, A, Rosen, H, Miller, B, Weiner, M, Perry, D, Turner, R, Reynolds, B, Mccann, K, Poe, J, Marshall, G, Sperling, R, Yesavage, J, Taylor, J, Chao, S, Coleman, J, White, J, Lane, B, Rosen, A, Tinklenberg, J, Belden, C, Atri, A, Clark, K, Zamrini, E, Sabbagh, M, Killiany, R, Stern, R, Mez, J, Kowall, N, Budson, A, Obisesan, T, Ntekim, O, Wolday, S, Khan, J, Nwulia, E, Nadarajah, S, Lerner, A, Ogrocki, P, Tatsuoka, C, Fatica, P, Fletcher, E, Maillard, P, Olichney, J, Decarli, C, Carmichael, O, Bates, V, Capote, H, Rainka, M, Borrie, M, Lee, T, Bartha, R, Johnson, S, Asthana, S, Carlsson, C, Perrin, A, Burke, A, Scharre, D, Kataki, M, Tarawneh, R, Hart, D, Zimmerman, E, Celmins, D, Miller, D, Ponto, L, Smith, K, Koleva, H, Shim, H, Nam, K, Schultz, S, Williamson, J, Craft, S, Cleveland, J, Yang, M, Sink, K, Ott, B, Drake, J, Tremont, G, Daiello, L, Ritter, A, Bernick, C, Munic, D, O'Connelll, A, Mintzer, J, Wiliams, A, Masdeu, J, Shi, J, Garcia, A, Newhouse, P, Potkin, S, Salloway, S, Malloy, P, Correia, S, Kittur, S, Pearlson, G, Blank, K, Anderson, K, Flashman, L, Seltzer, M, Hynes, M, Santulli, R, Relkin, N, Chiang, G, Lee, A, Lin, M, Ravdin, L, Tuena C., Maestri S., Serino S., Pedroli E., Stramba-Badiale M., Riva G., Silbert L. C., Lind B., Crissey R., Kaye J. A., Carter R., Dolen S., Quinn J., Schneider L. S., Pawluczyk S., Becerra M., Teodoro L., Dagerman K., Spann B. M., Brewer J., Fleisher A., Vanderswag H., Ziolkowski J., Heidebrink J. L., Zbizek-Nulph L., Lord J. L., Albers C. S., Petersen R., Mason S. S., Knopman D., Johnson K., Villanueva-Meyer J., Pavlik V., Pacini N., Lamb A., Kass J. S., Doody R. S., Shibley V., Chowdhury M., Rountree S., Dang M., Stern Y., Honig L. S., Mintz A., Ances B., Morris J. C., Winkfield D., Carroll M., Stobbs-Cucchi G., Oliver A., Creech M. L., Mintun M. A., Schneider S., Geldmacher D., Love M. N., Griffith R., Clark D., Brockington J., Marson D., Grossman H., Goldstein M. A., Greenberg J., Mitsis E., Shah R. C., Lamar M., Samuels P., Duara R., Greig-Custo M. T., Rodriguez R., Albert M., Onyike C., Farrington L., Rudow S., Brichko R., Kielb S., Smith A., Raj B. A., Fargher K., Sadowski M., Wisniewski T., Shulman M., Faustin A., Rao J., Castro K. M., Ulysse A., Chen S., Doraiswamy P. M., Petrella J. R., James O., Wong T. Z., Borges-Neto S., Karlawish J. H., Wolk D. A., Vaishnavi S., Clark C. M., Arnold S. E., Smith C. D., Jicha G. A., Khouli R. E., Raslau F. D., Lopez O. L., Oakley M. A., Simpson D. M., Porsteinsson A. P., Martin K., Kowalski N., Keltz M., Goldstein B. S., Makino K. M., Ismail M. S., Brand C., Thai G., Pierce A., Yanez B., Sosa E., Witbracht M., Kelley B., Nguyen T., Womack K., Mathews D., Quiceno M., Levey A. I., Lah J. J., Hajjar I., Burns J. M., Swerdlow R. H., Brooks W. M., Silverman D. H. S., Kremen S., Apostolova L., Tingus K., Lu P. H., Bartzokis G., Woo E., Teng E., Graff-Radford N. R., Parfitt F., Poki-Walker K., Farlow M. R., Hake A. M., Matthews B. R., Brosch J. R., Herring S., van Dyck C. H., Mecca A. P., Good S. P., MacAvoy M. G., Carson R. E., Varma P., Chertkow H., Vaitekunas S., Hosein C., Black S., Stefanovic B., Heyn C., Hsiung G. -Y. R., Kim E., Mudge B., Sossi V., Feldman H., Assaly M., Finger E., Pasternak S., Rachinsky I., Kertesz A., Drost D., Rogers J., Grant I., Muse B., Rogalski E., Robson J., Mesulam M. -M., Kerwin D., Wu C. -K., Johnson N., Lipowski K., Weintraub S., Bonakdarpour B., Pomara N., Hernando R., Sarrael A., Rosen H. J., Miller B. L., Weiner M. W., Perry D., Turner R. S., Reynolds B., MCCann K., Poe J., Marshall G. A., Sperling R. A., Johnson K. A., Yesavage J., Taylor J. L., Chao S., Coleman J., White J. D., Lane B., Rosen A., Tinklenberg J., Belden C. M., Atri A., Clark K. A., Zamrini E., Sabbagh M., Killiany R., Stern R., Mez J., Kowall N., Budson A. E., Obisesan T. O., Ntekim O. E., Wolday S., Khan J. I., Nwulia E., Nadarajah S., Lerner A., Ogrocki P., Tatsuoka C., Fatica P., Fletcher E., Maillard P., Olichney J., DeCarli C., Carmichael O., Bates V., Capote H., Rainka M., Borrie M., Lee T. -Y., Bartha R., Johnson S., Asthana S., Carlsson C. M., Perrin A., Burke A., Scharre D. W., Kataki M., Tarawneh R., Hart D., Zimmerman E. A., Celmins D., Miller D. D., Ponto L. L. B., Smith K. E., Koleva H., Shim H., Nam K. W., Schultz S. K., Williamson J. D., Craft S., Cleveland J., Yang M., Sink K. M., Ott B. R., Drake J., Tremont G., Daiello L. A., Drake J. D., Ritter A., Bernick C., Munic D., O'Connelll A., Mintzer J., Wiliams A., Masdeu J., Shi J., Garcia A., Newhouse P., Potkin S., Salloway S., Malloy P., Correia S., Kittur S., Pearlson G. D., Blank K., Anderson K., Flashman L. A., Seltzer M., Hynes M. L., Santulli R. B., Relkin N., Chiang G., Lee A., Lin M., Ravdin L., Tuena, C, Maestri, S, Serino, S, Pedroli, E, Stramba-Badiale, M, Riva, G, Silbert, L, Lind, B, Crissey, R, Kaye, J, Carter, R, Dolen, S, Quinn, J, Schneider, L, Pawluczyk, S, Becerra, M, Teodoro, L, Dagerman, K, Spann, B, Brewer, J, Fleisher, A, Vanderswag, H, Ziolkowski, J, Heidebrink, J, Zbizek-Nulph, L, Lord, J, Albers, C, Petersen, R, Mason, S, Knopman, D, Johnson, K, Villanueva-Meyer, J, Pavlik, V, Pacini, N, Lamb, A, Kass, J, Doody, R, Shibley, V, Chowdhury, M, Rountree, S, Dang, M, Stern, Y, Honig, L, Mintz, A, Ances, B, Morris, J, Winkfield, D, Carroll, M, Stobbs-Cucchi, G, Oliver, A, Creech, M, Mintun, M, Schneider, S, Geldmacher, D, Love, M, Griffith, R, Clark, D, Brockington, J, Marson, D, Grossman, H, Goldstein, M, Greenberg, J, Mitsis, E, Shah, R, Lamar, M, Samuels, P, Duara, R, Greig-Custo, M, Rodriguez, R, Albert, M, Onyike, C, Farrington, L, Rudow, S, Brichko, R, Kielb, S, Smith, A, Raj, B, Fargher, K, Sadowski, M, Wisniewski, T, Shulman, M, Faustin, A, Rao, J, Castro, K, Ulysse, A, Chen, S, Doraiswamy, P, Petrella, J, James, O, Wong, T, Borges-Neto, S, Karlawish, J, Wolk, D, Vaishnavi, S, Clark, C, Arnold, S, Smith, C, Jicha, G, Khouli, R, Raslau, F, Lopez, O, Oakley, M, Simpson, D, Porsteinsson, A, Martin, K, Kowalski, N, Keltz, M, Goldstein, B, Makino, K, Ismail, M, Brand, C, Thai, G, Pierce, A, Yanez, B, Sosa, E, Witbracht, M, Kelley, B, Nguyen, T, Womack, K, Mathews, D, Quiceno, M, Levey, A, Lah, J, Hajjar, I, Burns, J, Swerdlow, R, Brooks, W, Silverman, D, Kremen, S, Apostolova, L, Tingus, K, Lu, P, Bartzokis, G, Woo, E, Teng, E, Graff-Radford, N, Parfitt, F, Poki-Walker, K, Farlow, M, Hake, A, Matthews, B, Brosch, J, Herring, S, van Dyck, C, Mecca, A, Good, S, Macavoy, M, Carson, R, Varma, P, Chertkow, H, Vaitekunas, S, Hosein, C, Black, S, Stefanovic, B, Heyn, C, Hsiung, G, Kim, E, Mudge, B, Sossi, V, Feldman, H, Assaly, M, Finger, E, Pasternak, S, Rachinsky, I, Kertesz, A, Drost, D, Rogers, J, Grant, I, Muse, B, Rogalski, E, Robson, J, Mesulam, M, Kerwin, D, Wu, C, Johnson, N, Lipowski, K, Weintraub, S, Bonakdarpour, B, Pomara, N, Hernando, R, Sarrael, A, Rosen, H, Miller, B, Weiner, M, Perry, D, Turner, R, Reynolds, B, Mccann, K, Poe, J, Marshall, G, Sperling, R, Yesavage, J, Taylor, J, Chao, S, Coleman, J, White, J, Lane, B, Rosen, A, Tinklenberg, J, Belden, C, Atri, A, Clark, K, Zamrini, E, Sabbagh, M, Killiany, R, Stern, R, Mez, J, Kowall, N, Budson, A, Obisesan, T, Ntekim, O, Wolday, S, Khan, J, Nwulia, E, Nadarajah, S, Lerner, A, Ogrocki, P, Tatsuoka, C, Fatica, P, Fletcher, E, Maillard, P, Olichney, J, Decarli, C, Carmichael, O, Bates, V, Capote, H, Rainka, M, Borrie, M, Lee, T, Bartha, R, Johnson, S, Asthana, S, Carlsson, C, Perrin, A, Burke, A, Scharre, D, Kataki, M, Tarawneh, R, Hart, D, Zimmerman, E, Celmins, D, Miller, D, Ponto, L, Smith, K, Koleva, H, Shim, H, Nam, K, Schultz, S, Williamson, J, Craft, S, Cleveland, J, Yang, M, Sink, K, Ott, B, Drake, J, Tremont, G, Daiello, L, Ritter, A, Bernick, C, Munic, D, O'Connelll, A, Mintzer, J, Wiliams, A, Masdeu, J, Shi, J, Garcia, A, Newhouse, P, Potkin, S, Salloway, S, Malloy, P, Correia, S, Kittur, S, Pearlson, G, Blank, K, Anderson, K, Flashman, L, Seltzer, M, Hynes, M, Santulli, R, Relkin, N, Chiang, G, Lee, A, Lin, M, Ravdin, L, Tuena C., Maestri S., Serino S., Pedroli E., Stramba-Badiale M., Riva G., Silbert L. C., Lind B., Crissey R., Kaye J. A., Carter R., Dolen S., Quinn J., Schneider L. S., Pawluczyk S., Becerra M., Teodoro L., Dagerman K., Spann B. M., Brewer J., Fleisher A., Vanderswag H., Ziolkowski J., Heidebrink J. L., Zbizek-Nulph L., Lord J. L., Albers C. S., Petersen R., Mason S. S., Knopman D., Johnson K., Villanueva-Meyer J., Pavlik V., Pacini N., Lamb A., Kass J. S., Doody R. S., Shibley V., Chowdhury M., Rountree S., Dang M., Stern Y., Honig L. S., Mintz A., Ances B., Morris J. C., Winkfield D., Carroll M., Stobbs-Cucchi G., Oliver A., Creech M. L., Mintun M. A., Schneider S., Geldmacher D., Love M. N., Griffith R., Clark D., Brockington J., Marson D., Grossman H., Goldstein M. A., Greenberg J., Mitsis E., Shah R. C., Lamar M., Samuels P., Duara R., Greig-Custo M. T., Rodriguez R., Albert M., Onyike C., Farrington L., Rudow S., Brichko R., Kielb S., Smith A., Raj B. A., Fargher K., Sadowski M., Wisniewski T., Shulman M., Faustin A., Rao J., Castro K. M., Ulysse A., Chen S., Doraiswamy P. M., Petrella J. R., James O., Wong T. Z., Borges-Neto S., Karlawish J. H., Wolk D. A., Vaishnavi S., Clark C. M., Arnold S. E., Smith C. D., Jicha G. A., Khouli R. E., Raslau F. D., Lopez O. L., Oakley M. A., Simpson D. M., Porsteinsson A. P., Martin K., Kowalski N., Keltz M., Goldstein B. S., Makino K. M., Ismail M. S., Brand C., Thai G., Pierce A., Yanez B., Sosa E., Witbracht M., Kelley B., Nguyen T., Womack K., Mathews D., Quiceno M., Levey A. I., Lah J. J., Hajjar I., Burns J. M., Swerdlow R. H., Brooks W. M., Silverman D. H. S., Kremen S., Apostolova L., Tingus K., Lu P. H., Bartzokis G., Woo E., Teng E., Graff-Radford N. R., Parfitt F., Poki-Walker K., Farlow M. R., Hake A. M., Matthews B. R., Brosch J. R., Herring S., van Dyck C. H., Mecca A. P., Good S. P., MacAvoy M. G., Carson R. E., Varma P., Chertkow H., Vaitekunas S., Hosein C., Black S., Stefanovic B., Heyn C., Hsiung G. -Y. R., Kim E., Mudge B., Sossi V., Feldman H., Assaly M., Finger E., Pasternak S., Rachinsky I., Kertesz A., Drost D., Rogers J., Grant I., Muse B., Rogalski E., Robson J., Mesulam M. -M., Kerwin D., Wu C. -K., Johnson N., Lipowski K., Weintraub S., Bonakdarpour B., Pomara N., Hernando R., Sarrael A., Rosen H. J., Miller B. L., Weiner M. W., Perry D., Turner R. S., Reynolds B., MCCann K., Poe J., Marshall G. A., Sperling R. A., Johnson K. A., Yesavage J., Taylor J. L., Chao S., Coleman J., White J. D., Lane B., Rosen A., Tinklenberg J., Belden C. M., Atri A., Clark K. A., Zamrini E., Sabbagh M., Killiany R., Stern R., Mez J., Kowall N., Budson A. E., Obisesan T. O., Ntekim O. E., Wolday S., Khan J. I., Nwulia E., Nadarajah S., Lerner A., Ogrocki P., Tatsuoka C., Fatica P., Fletcher E., Maillard P., Olichney J., DeCarli C., Carmichael O., Bates V., Capote H., Rainka M., Borrie M., Lee T. -Y., Bartha R., Johnson S., Asthana S., Carlsson C. M., Perrin A., Burke A., Scharre D. W., Kataki M., Tarawneh R., Hart D., Zimmerman E. A., Celmins D., Miller D. D., Ponto L. L. B., Smith K. E., Koleva H., Shim H., Nam K. W., Schultz S. K., Williamson J. D., Craft S., Cleveland J., Yang M., Sink K. M., Ott B. R., Drake J., Tremont G., Daiello L. A., Drake J. D., Ritter A., Bernick C., Munic D., O'Connelll A., Mintzer J., Wiliams A., Masdeu J., Shi J., Garcia A., Newhouse P., Potkin S., Salloway S., Malloy P., Correia S., Kittur S., Pearlson G. D., Blank K., Anderson K., Flashman L. A., Seltzer M., Hynes M. L., Santulli R. B., Relkin N., Chiang G., Lee A., Lin M., and Ravdin L.

Abstract

Background: Increasing research suggests that gait abnormalities can be a risk factor for Alzheimer’s Disease (AD). Notably, there is growing evidence highlighting this risk factor in individuals with amnestic Mild Cognitive Impairment (aMCI), however further studies are needed. The aim of this study is to analyze cognitive tests results and brain-related measures over time in aMCI and examine how the presence of gait abnormalities (neurological or orthopedic) or normal gait affects these trends. Additionally, we sought to assess the significance of gait and gait-related measures as prognostic indicators for the progression from aMCI to AD dementia, comparing those who converted to AD with those who remained with a stable aMCI diagnosis during the follow-up. Methods: Four hundred two individuals with aMCI from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database were included. Robust linear mixed-effects models were used to study the impact of gait abnormalities on a comprehensive neuropsychological battery over 36 months while controlling for relevant medical variables at baseline. The impact of gait on brain measures was also investigated. Lastly, the Cox proportional-hazards model was used to explore the prognostic relevance of abnormal gait and neuropsychological associated tests. Results: While controlling for relevant covariates, we found that gait abnormalities led to a greater decline over time in attention (DSST) and global cognition (MMSE). Intriguingly, psychomotor speed (TMT-A) and divided attention (TMT-B) declined uniquely in the abnormal gait group. Conversely, specific AD global cognition tests (ADAS-13) and auditory-verbal memory (RAVLT immediate recall) declined over time independently of gait profile. All the other cognitive tests were not significantly affected by time or by gait profile. In addition, we found that ventricles size increased faster in the abnormal gait group compared to the normal gait group. In terms of prognosis, abno

Published
2023

10. Safety and efficacy of tilavonemab in progressive supranuclear palsy: a phase 2, randomised, placebo-controlled trial

Author

Hoglinger, G. U., Litvan, I., Mendonca, N., Wang, D., Zheng, H., Rendenbach-Mueller, B., Lon, H. -K., Jin, Z., Fisseha, N., Budur, K., Gold, M., Ryman, D., Florian, H., Ahmed, A., Aiba, I., Albanese, Alberto, Bertram, K., Bordelon, Y., Bower, J., Brosch, J., Claassen, D., Colosimo, C., Corvol, J. -C., Cudia, P., Daniele, Antonio, Defebvre, L., Driver-Dunckley, E., Duquette, A., Eleopra, R., Eusebio, A., Fung, V., Geldmacher, D., Golbe, L., Grandas, F., Hall, D., Hatano, T., Honig, L., Hui, J., Kerwin, D., Kikuchi, A., Kimber, T., Kimura, T., Kumar, R., Ljubenkov, P., Lorenzl, S., Ludolph, A., Mari, Z., Mcfarland, N., Meissner, W., Mir Rivera, P., Mochizuki, H., Morgan, J., Munhoz, R., Nishikawa, N., O`sullivan, J., Oeda, T., Oizumi, H., Onodera, O., Ory-Magne, F., Peckham, E., Postuma, R., Quattrone, A., Quinn, J., Ruggieri, S., Sarna, J., Schulz, P. E., Slevin, J., Tagliati, M., Wile, D., Wszolek, Z., Xie, T., Zesiewicz, T., Albanese A. (ORCID:0000-0002-5864-0006), Hoglinger, G. U., Litvan, I., Mendonca, N., Wang, D., Zheng, H., Rendenbach-Mueller, B., Lon, H. -K., Jin, Z., Fisseha, N., Budur, K., Gold, M., Ryman, D., Florian, H., Ahmed, A., Aiba, I., Albanese, Alberto, Bertram, K., Bordelon, Y., Bower, J., Brosch, J., Claassen, D., Colosimo, C., Corvol, J. -C., Cudia, P., Daniele, Antonio, Defebvre, L., Driver-Dunckley, E., Duquette, A., Eleopra, R., Eusebio, A., Fung, V., Geldmacher, D., Golbe, L., Grandas, F., Hall, D., Hatano, T., Honig, L., Hui, J., Kerwin, D., Kikuchi, A., Kimber, T., Kimura, T., Kumar, R., Ljubenkov, P., Lorenzl, S., Ludolph, A., Mari, Z., Mcfarland, N., Meissner, W., Mir Rivera, P., Mochizuki, H., Morgan, J., Munhoz, R., Nishikawa, N., O`sullivan, J., Oeda, T., Oizumi, H., Onodera, O., Ory-Magne, F., Peckham, E., Postuma, R., Quattrone, A., Quinn, J., Ruggieri, S., Sarna, J., Schulz, P. E., Slevin, J., Tagliati, M., Wile, D., Wszolek, Z., Xie, T., Zesiewicz, T., and Albanese A. (ORCID:0000-0002-5864-0006)

Abstract

Background: Progressive supranuclear palsy is a neurodegenerative disorder associated with tau protein aggregation. Tilavonemab (ABBV-8E12) is a monoclonal antibody that binds to the N-terminus of human tau. We assessed the safety and efficacy of tilavonemab for the treatment of progressive supranuclear palsy. Methods: We did a phase 2, multicentre, randomised, placebo-controlled, double-blind study at 66 hospitals and clinics in Australia, Canada, France, Germany, Italy, Japan, Spain, and the USA. Participants (aged ≥40 years) diagnosed with possible or probable progressive supranuclear palsy who were symptomatic for less than 5 years, had a reliable study partner, and were able to walk five steps with minimal assistance, were randomly assigned (1:1:1) by interactive response technology to tilavonemab 2000 mg, tilavonemab 4000 mg, or matching placebo administered intravenously on days 1, 15, and 29, then every 28 days through to the end of the 52-week treatment period. Randomisation was done by the randomisation specialist of the study sponsor, who did not otherwise participate in the study. The sponsor, investigators, and participants were unaware of treatment allocations. The primary endpoint was the change from baseline to week 52 in the Progressive Supranuclear Palsy Rating Scale (PSPRS) total score in the intention-to-treat population. Adverse events were monitored in participants who received at least one dose of study drug. Prespecified interim futility criteria were based on a model-based effect size of 0 or lower when 60 participants had completed the 52-week treatment period and 0·12 or lower when 120 participants had completed the 52-week treatment period. This study is registered at ClinicalTrials.gov, number NCT02985879. Findings: Between Dec 12, 2016, and Dec 31, 2018, 466 participants were screened, 378 were randomised. The study was terminated on July 3, 2019, after prespecified futility criteria were met at the second interim analysis. A total of 3

Published
2021

11. Atmospheric chemistry of linear perfluorinated aldehydes: Dissociation kinetics of [C.sub.n][F.sub.2n+1]CO radicals

Author

Waterland, Robert L. and Dobbs, Kerwin D.

Subjects
Aldehydes -- Chemical properties, Atmospheric chemistry -- Research, Fluorine compounds -- Chemical properties, Oxidation-reduction reaction -- Research, Chemicals, plastics and rubber industries
Abstract

Ab initio quantum chemistry calculations of the decarbonylation kinetics of [C.sub.n][F.sub.2n+1]CO radicals are reported. The results have shown that [C.sub.n][F.sub.2n+1]CO radicals have a strong tendency to decompose in order to give [C.sub.n][F.sub.2n+1] and CO under atmospheric conditions.

Published
2007

12. Practical recommendations for timely, accurate diagnosis of symptomatic Alzheimer’s disease (MCI and dementia) in primary care: a review and synthesis

Author

Liss, J. L., primary, Seleri Assunção, S., additional, Cummings, J., additional, Atri, A., additional, Geldmacher, D. S., additional, Candela, S. F., additional, Devanand, D. P., additional, Fillit, H. M., additional, Susman, J., additional, Mintzer, J., additional, Bittner, T., additional, Brunton, S. A., additional, Kerwin, D. R., additional, Jackson, W. C., additional, Small, G. W., additional, Grossberg, G. T., additional, Clevenger, C. K., additional, Cotter, V., additional, Stefanacci, R., additional, Wise‐Brown, A., additional, and Sabbagh, M. N., additional

Published
2021
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14. A Raman spectroscopy study of the separation of hydrofluorocarbons using zeolites

Author

Crawford, Michael K., Dobbs, Kerwin D., Smalley, Robert J., Corbin, David R., Maliszewskyj, Nicholas, Udovic, Terrence J., Cavanagh, Richard R., Rush, John J., and Grey, Clare P.

Subjects
Raman spectroscopy -- Usage, Hydrofluorocarbons -- Research, Zeolites -- Research, Chemicals, plastics and rubber industries
Abstract

The separation of the hydrofluorocarbon (HFC)-134a from its isomer HFC-134via the differential surface adsorption on the zeolite NaX was investigated using Raman spectroscopy. The trans-gauche population ratio for HFC-134 adsorbed on NaX was found to decrease by up to 20-fold compared to the gas phase. The conformational ratio was also found to change with the HFC loading, with the polar gauche conformer being more preferred when the separation factor is maximum.

Published
1999

15. Quality Assessment of Mangoes using Convolutional Neural Network

Author

Argel A. Bandala, Edwin J. Calilune, Arlene C. Joaquin, Elmer P. Dadios, John Carlo V. Puno, and Robert Kerwin D. Billones

Subjects
business.industry, Computer science, Quality assessment, media_common.quotation_subject, Intelligent decision support system, Conveyor belt, Image processing, Sweet taste, Machine learning, computer.software_genre, Convolutional neural network, Automation, Quality (business), Artificial intelligence, business, computer, media_common
Abstract

Philippines is one of the countries in the world known for exporting good quality crops. Mangoes in the Philippines are very popular for its good sweet taste and considerably one of the best. Hence, ensuring the quality of the crop to be exported is essential. The study focused on utilizing convolutional neural network in determining the quality of carabao mango (Mangifera Indica). To make sure that all sides of the mango is going to be considered for the quality assessment, a mechanical system that uses conveyor belt, rollers, and camera was used to gather videos for training and validation of the model. The videos were extracted into frames and gone through image processing to remove the background and retain the mango only. The dataset is composed of different mangoes having both good and bad qualities. The implemented model used a total of 5550 training samples with 94.99% accuracy and a total of 2320 samples used for validation with an accuracy of 97.21%.

Published
2019
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17. Mechanistic insight into gas-phase reactions of H. + Si2H6 and hydrogen atom etching of silicon surfaces

Author

Dobbs, Kerwin D. and Doren, Douglas J.

Subjects
Silane -- Research, Hydrogen -- Research, Crystals -- Etching, Scission (Chemistry) -- Research, Chemistry
Abstract

Ab initio studies, using high-level electronic structure methods (PMP4), probe into the mechanism of the gas-phase reaction, H + Si2H6, the putative final step in the etching of silicon surfaces by hydrogen atoms. The studies confirm that Si-Si bond cleavage by hydrogen atoms proceeds via a frontside attack rather than the more energetically demanding backside attack of the silyl group. Strongly competing for this frontside reaction is hydrogen abstraction. The calculations agree well with known empirical results.

Published
1993

19. A blood-based signature of cerebrospinal fluid A beta(1-42) status

Author

Goudey, B., Fung, B.J., Schieber, C., Faux, N.G., Weiner, M.W., Aisen, P., Petersen, R., Jack, C.R., Jagust, W., Trojanowki, J.Q., Toga, A.W., Beckett, L., Green, R.C., Saykin, A.J., Morris, J., Shaw, L.M., Kaye, J., Quinn, J., Silbert, L., Lind, B., Carter, R., Dolen, S., Schneider, L.S., Pawluczyk, S., Beccera, M., Teodoro, L., Spann, B.M., Brewer, J., Vanderswag, H., Fleisher, A., Heidebrink, J.L., Lord, J.L., Mason, S.S., Albers, C.S., Knopman, D., Johnson, K., Doody, R.S., Villanueva-Meyer, J., Chowdhury, M., Rountree, S., Dang, M., Stern, Y., Honig, L.S., Bell, K.L., Ances, B., Morris, J.C., Carroll, M., Creech, M.L., Franklin, E., Mintun, M.A., Schneider, S., Oliver, A., Marson, D., Griffth, R., Clark, D., Geldmacher, D., Brockington, J., Roberson, E., Natelson Love, M., Grossman, H., Mitsis, E., Shah, R.C., deToledo-Morrell, L., Duara, R., Varon, D., Greig, M.T., Roberts, P., Albert, M., Onyike, C., D'Agostino, D., Kielb, S., Galvin, J.E., Cerbone, B., Michel, C.A., Pogorelec, D.M., Rusinek, H., Leon, M.J. de, Glodzik, L., De Santi, S., Doraiswamy, P.M., Petrella, J.R., Borges-Neto, S., Wong, T.Z., Coleman, E., Smith, C.D., Jicha, G., Hardy, P., Sinha, P., Oates, E., Conrad, G., Porsteinsson, A.P., Goldstein, B.S., Martin, K., Makino, K.M., Ismail, M.S., Brand, C., Mulnard, R.A., Thai, G., McAdams-Ortiz, C., Womack, K., Mathews, D., Quiceno, M., Levey, A.I., Lah, J.J., Cellar, J.S., Burns, J.M., Swerdlow, R.H., Brooks, W.M., Apostolova, L., Tingus, K., Woo, E., Silverman, D.H.S., Lu, P.H., Bartzokis, G., Graff-Radford, N.R., Parftt, F., Kendall, T., Johnson, H., Farlow, M.R., Hake, A.M., Matthews, B.R., Brosch, J.R., Herring, S., Hunt, C., Dyck, .H. van, Carson, R.E., MacAvoy, M.G., Varma, P., Chertkow, H., Bergman, H., Hosein, C., Black, S., Stefanovic, B., Caldwell, C., Hsiung, Ging-Yuek Robin, Feldman, H., Mudge, B., Assaly, M., Finger, E., Pasternack, S., Rachisky, I., Trost, D., Kertesz, A., Bernick, C., Munic, D., Mesulam, M.-M., Lipowski, K., Weintraub, S., Bonakdarpour, B., Kerwin, D., Wu, C.-K., Johnson, N., Sadowsky, C., Villena, T., Turner, R.S., Reynolds, B., Sperling, R.A., Johnson, K.A., Marshall, G., Yesavage, J., Taylor, J.L., Lane, B., Rosen, A., Tinklenberg, J., Sabbagh, M.N., Belden, C.M., Jacobson, S.A., Sirrel, S.A., Kowall, N., Killiany, R., Budson, A.E., Norbash, A., Johnson, P.L., Obisesan, T.O., Wolday, S., Allard, J., Lerner, A., Ogrocki, P., Tatsuoka, C., Fatica, P., Fletcher, E., Maillard, P., Olichney, J., DeCarli, C., Carmichael, O., Kittur, S., Borrie, M., Lee, T.-Y., Bartha, R., Johnson, S., Asthana, S., Carlsson, C.M., Potkin, S.G., Preda, A., Nguyen, D., Tariot, P., Burke, A., Trncic, N., Reeder, S., Bates, V., Capote, H., Rainka, M., Scharre, D.W., Kataki, M., Adeli, A., Zimmerman, E.A., Celmins, D., Brown, A.D., Pearlson, G.D., Blank, K., Anderson, K., Flashman, L.A., Seltzer, M., Hynes, M.L., Santulli, R.B., Sink, K.M., Gordineer, L., Williamson, J.D., Garg, P., Watkins, F., Ott, B.R., Querfurth, H., Tremont, G., Salloway, S., Malloy, P., Correia, S., Rosen, H.J., Miller, B.L., Perry, D., Mintzer, J., Spicer, K., Bachman, D., Pomara, N., Hernando, R., Sarrael, A., Relkin, N., Chaing, G., Lin, M., Ravdin, L., Smith, A., Raj, B.A., Fargher, K., Saykin, A., Nho, K., Kling, M., Toledo, J., Shaw, L., Trojanowski, J., Farrer, L., Kastsenmueller, G., Arnold, M., Wishart, D., Wurtz, P., Bhattcharyya, S., Duijin, C. van, Mangravite, L., Han, X., Hankemeier, T., Fiehn, O., Barupal, D., Thiele, I., Heinken, A., Meikle, P., Price, N., Funk, C., Jia, W., Kueider-Paisley, A., Tenebaum, J., Black, C., Moseley, A., Thompson, W., Mahmoudiandehkorki, S., Baillie, R., Welsh-Bohmer, K., Plassman, B., and Epidemiology

Subjects
Male, 0301 basic medicine, Apolipoprotein E, Oncology, medicine.medical_specialty, Amyloid, Amyloid beta, lcsh:Medicine, Article, 03 medical and health sciences, Apolipoproteins E, 0302 clinical medicine, Cerebrospinal fluid, Alzheimer Disease, Predictive Value of Tests, Internal medicine, medicine, Humans, Dementia, Cognitive decline, lcsh:Science, Aged, Aged, 80 and over, Amyloid beta-Peptides, Multidisciplinary, biology, Chemokine CCL26, business.industry, lcsh:R, Alzheimer’s Disease Metabolomics Consortium, Alzheimer’s Disease Neuroimaging Initiative, medicine.disease, Peptide Fragments, 3. Good health, 030104 developmental biology, biology.protein, Chromogranin A, Female, lcsh:Q, Alzheimer's disease, business, Biomarkers, 030217 neurology & neurosurgery, Alzheimer's Disease Neuroimaging Initiative
Abstract

It is increasingly recognized that Alzheimer’s disease (AD) exists before dementia is present and that shifts in amyloid beta occur long before clinical symptoms can be detected. Early detection of these molecular changes is a key aspect for the success of interventions aimed at slowing down rates of cognitive decline. Recent evidence indicates that of the two established methods for measuring amyloid, a decrease in cerebrospinal fluid (CSF) amyloid β1−42 (Aβ1−42) may be an earlier indicator of Alzheimer’s disease risk than measures of amyloid obtained from Positron Emission Tomography (PET). However, CSF collection is highly invasive and expensive. In contrast, blood collection is routinely performed, minimally invasive and cheap. In this work, we develop a blood-based signature that can provide a cheap and minimally invasive estimation of an individual’s CSF amyloid status using a machine learning approach. We show that a Random Forest model derived from plasma analytes can accurately predict subjects as having abnormal (low) CSF Aβ1−42 levels indicative of AD risk (0.84 AUC, 0.78 sensitivity, and 0.73 specificity). Refinement of the modeling indicates that only APOEε4 carrier status and four plasma analytes (CGA, Aβ1−42, Eotaxin 3, APOE) are required to achieve a high level of accuracy. Furthermore, we show across an independent validation cohort that individuals with predicted abnormal CSF Aβ1−42 levels transitioned to an AD diagnosis over 120 months significantly faster than those with predicted normal CSF Aβ1−42 levels and that the resulting model also validates reasonably across PET Aβ1−42 status (0.78 AUC). This is the first study to show that a machine learning approach, using plasma protein levels, age and APOEε4 carrier status, is able to predict CSF Aβ1−42 status, the earliest risk indicator for AD, with high accuracy.

Published
2019
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24. Highly Quantum Efficient Phosphorescent Sky Blue Emitters Based on Diastereomeric Iridium(III) Complexes of Atropisomeric 5-Aryl-4H-1,2,4-triazole Ligands

Author

Will J. Marshall, Lois M. Bryman, Joseph Buriak, Troy C. Gehret, Kyung-Ho Park, Steve G. Zane, Thomas H. Scholz, Jeffrey S. Meth, Jerald Feldman, Charles D. McLaren, Kerwin D. Dobbs, and Giang D. Vo

Subjects
Atropisomer, Ligand, Aryl, Organic Chemistry, Triazole, Diastereomer, chemistry.chemical_element, Photochemistry, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Polymer chemistry, Iridium, Physical and Theoretical Chemistry, Homoleptic, Phosphorescence
Abstract

Homoleptic fac-IrIIIL3 complexes of 5-aryl-4H-1,2,4-triazole ligands are sky blue emitters. When unsymmetrically substituted, the triazole ligands exhibit atropisomerism, and upon cyclometalation to Ir(III) a mixture of diastereomers is formed. We have isolated and structurally characterized all four possible diastereomers of the fac-IrIIIL3 complex formed upon cyclometalation of an atropisomeric 5-aryl-4H-1,2,4-triazole ligand onto Ir(III). The phosphorescent blue emitting materials reported herein are among the most efficient to date, with quantum efficiencies above 95%.

Published
2015
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25. Uncovering the heterogeneity and temporal complexity of neurodegenerative diseases with Subtype and Stage Inference

Author

Young, A. L., Marinescu, R. V., Oxtoby, N. P., Bocchetta, M., Yong, K., Firth, N. C., Cash, D. M., Thomas, D. L., Dick, K. M., Cardoso, J., van Swieten, J., Borroni, B., Galimberti, D., Masellis, M., Tartaglia, M. C., Rowe, J. B., Graff, C., Tagliavini, F., Frisoni, G. B., Laforce, R., Finger, E., de Mendonca, A., Sorbi, S., Warren, J. D., Crutch, S., Fox, N. C., Ourselin, S., Schott, J. M., Rohrer, J. D., Alexander, D. C., Andersson, C., Archetti, S., Arighi, A., Benussi, L., Binetti, G., Black, S., Cosseddu, M., Fallstrom, M., Ferreira, C., Fenoglio, C., Freedman, M., Fumagalli, G. G., Gazzina, S., Ghidoni, R., Grisoli, M., Jelic, V., Jiskoot, L., Keren, R., Lombardi, G., Maruta, C., Meeter, L., Mead, S., van Minkelen, R., Nacmias, B., Oijerstedt, L., Padovani, A., Panman, J., Pievani, M., Polito, C., Premi, E., Prioni, S., Rademakers, R., Redaelli, V., Rogaeva, E., Rossi, G., Rossor, M., Scarpini, E., Tang-Wai, D., Thonberg, H., Tiraboschi, P., Verdelho, A., Weiner, M. W., Aisen, P., Petersen, R., Jack, C. R., Jagust, W., Trojanowki, J. Q., Toga, A. W., Beckett, L., Green, R. C., Saykin, A. J., Morris, J., Shaw, L. M., Khachaturian, Z., Sorensen, G., Kuller, L., Raichle, M., Paul, S., Davies, P., Fillit, H., Hefti, F., Holtzman, D., Mesulam, M. M., Potter, W., Snyder, P., Schwartz, A., Montine, T., Thomas, R. G., Donohue, M., Walter, S., Gessert, D., Sather, T., Jiminez, G., Harvey, D., Bernstein, M., Thompson, P., Schuff, N., Borowski, B., Gunter, J., Senjem, M., Vemuri, P., Jones, D., Kantarci, K., Ward, C., Koeppe, R. A., Foster, N., Reiman, E. M., Chen, K., Mathis, C., Landau, S., Cairns, N. J., Householder, E., Taylor-Reinwald, L., Lee, V., Korecka, M., Figurski, M., Crawford, K., Neu, S., Foroud, T. M., Potkin, S., Shen, L., Faber, K., Kim, S., Nho, K., Thal, L., Buckholtz, N., Albert, M., Frank, R., Hsiao, J., Kaye, J., Quinn, J., Lind, B., Carter, R., Dolen, S., Schneider, L. S., Pawluczyk, S., Beccera, M., Teodoro, L., Spann, B. M., Brewer, J., Vanderswag, H., Fleisher, A., Heidebrink, J. L., Lord, J. L., Mason, S. S., Albers, C. S., Knopman, D., Johnson, K., Doody, R. S., Villanueva-Meyer, J., Chowdhury, M., Rountree, S., Dang, M., Stern, Y., Honig, L. S., Bell, K. L., Ances, B., Carroll, M., Leon, S., Mintun, M. A., Schneider, S., Oliver, A., Marson, D., Griffith, R., Clark, D., Geldmacher, D., Brockington, J., Roberson, E., Grossman, H., Mitsis, E., de Toledo-Morrell, L., Shah, R. C., Duara, R., Varon, D., Greig, M. T., Roberts, P., Onyike, C., D'Agostino, D., Kielb, S., Galvin, J. E., Cerbone, B., Michel, C. A., Rusinek, H., de Leon, M. J., Glodzik, L., De Santi, S., Doraiswamy, P. M., Petrella, J. R., Wong, T. Z., Arnold, S. E., Karlawish, J. H., Wolk, D., Smith, C. D., Jicha, G., Hardy, P., Sinha, P., Oates, E., Conrad, G., Lopez, O. L., Oakley, M. A., Simpson, D. M., Porsteinsson, A. P., Goldstein, B. S., Martin, K., Makino, K. M., Ismail, M. S., Brand, C., Mulnard, R. A., Thai, G., Mc-Adams-Ortiz, C., Womack, K., Mathews, D., Quiceno, M., Diaz-Arrastia, R., King, R., Weiner, M., Martin-Cook, K., Devous, M., Levey, A. I., Lah, J. J., Cellar, J. S., Burns, J. M., Anderson, H. S., Swerdlow, R. H., Apostolova, L., Tingus, K., Woo, E., Silverman, D. H., P. H., Lu, Bartzokis, G., Graff-Radford, N. R., Parfitt, F., Kendall, T., Johnson, H., Farlow, M. R., Hake, A. M., Matthews, B. R., Herring, S., Hunt, C., van Dyck, C. H., Carson, R. E., Macavoy, M. G., Chertkow, H., Bergman, H., Hosein, C., Stefanovic, B., Caldwell, C., Hsiung, G. -Y. R., Feldman, H., Mudge, B., Assaly, M., Kertesz, A., Rogers, J., Bernick, C., Munic, D., Kerwin, D., Mesulam, M. -M., Lipowski, K., C. -K., Wu, Johnson, N., Sadowsky, C., Martinez, W., Villena, T., Turner, R. S., Reynolds, B., Sperling, R. A., Johnson, K. A., Marshall, G., Frey, M., Lane, B., Rosen, A., Tinklenberg, J., Sabbagh, M. N., Belden, C. M., Jacobson, S. A., Sirrel, S. A., Kowall, N., Killiany, R., Budson, A. E., Norbash, A., Johnson, P. L., Allard, J., Lerner, A., Ogrocki, P., Hudson, L., Fletcher, E., Carmichael, O., Olichney, J., Decarli, C., Kittur, S., Borrie, M., Lee, T. -Y., Bartha, R., Johnson, S., Asthana, S., Carlsson, C. M., Potkin, S. G., Preda, A., Nguyen, D., Tariot, P., Reeder, S., Bates, V., Capote, H., Rainka, M., Scharre, D. W., Kataki, M., Adeli, A., Zimmerman, E. A., Celmins, D., Brown, A. D., Pearlson, G. D., Blank, K., Anderson, K., Santulli, R. B., Kitzmiller, T. J., Schwartz, E. S., Sink, K. M., Williamson, J. D., Garg, P., Watkins, F., Ott, B. R., Querfurth, H., Tremont, G., Salloway, S., Malloy, P., Correia, S., Rosen, H. J., Miller, B. L., Mintzer, J., Spicer, K., Bachman, D., Pasternak, S., Rachinsky, I., Drost, D., Pomara, N., Hernando, R., Sarrael, A., Schultz, S. K., Ponto, L. L. B., Shim, H., Smith, K. E., Relkin, N., Chaing, G., Raudin, L., Smith, A., Fargher, K., Raj, B. A., Neylan, T., Grafman, J., Davis, M., Morrison, R., Hayes, J., Finley, S., Friedl, K., Fleischman, D., Arfanakis, K., James, O., Massoglia, D., Fruehling, J. J., Harding, S., Peskind, E. R., Petrie, E. C., Li, G., Yesavage, J. A., Taylor, J. L., and Furst, A. J.

Published
2018

26. Insect detection and monitoring in stored grains using MFCCs and artificial neural network

Author

Edwin J. Calilung, Edwin Sybingco, Elmer P. Dadios, Robert Kerwin D. Billones, Stephenn L. Rabano, and Robert Martin C. Santiago

Subjects
0106 biological sciences, Artificial neural network, Computer science, business.industry, Feature extraction, Pattern recognition, 02 engineering and technology, Grain storage, 01 natural sciences, Signal, 010602 entomology, 0202 electrical engineering, electronic engineering, information engineering, Grain quality, 020201 artificial intelligence & image processing, Network performance, Artificial intelligence, Mel-frequency cepstrum, business, Network model
Abstract

The variability in grain production makes it necessary to have strategic grain storage plans in order to ensure adequate supplies at all times. However, insects in stored grain products cause infestation and contamination which reduce grain quality and quantity. In order to prevent these problems, early detection and constant monitoring need to be implemented. Acoustic methods have been established in numerous studies as a viable approach for insect detection and monitoring with various sound parameterization and classification techniques. The aim of this study is to further demonstrate the efficacy of acoustic methods in pest management mainly through feature extraction using Mel-frequency cepstral coefficients (MFCCs) and classification using artificial neural network. The study used sounds from the Sitophilus oryzae (L.) or commonly known as rice weevil in larval stage recorded using five different acoustic sensors with the purpose of proving the capability of artificial neural network to recognize insect sounds regardless of the acoustic sensors used. Network models with varying number of nodes for the hidden layer were experimented in search for the highest accuracy that may be obtained. Results show that the network with 25 nodes for the hidden layer provides the best over-all network performance with 94.70% accuracy and the training, validation, and testing are accurate at 95.10%, 94.00%, and 93.60% respectively. Although, difference in accuracy values across all simulations never exceeded 1%. These show that the proposed method is capable of recognizing insect sounds regardless of the acoustic sensors used provided that proper acoustic signal preprocessing, feature extraction, and implementation of the network are performed.

Published
2017
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27. Phosphorescent Iridium(III) Complexes of Cyclometalated 5-Aryl-1H-1,2,4-Triazole Ligands: Structural, Computational, Spectroscopic, and Device Studies

Author

Jeffrey S. Meth, Giang D. Vo, Ying Wang, Will J. Marshall, Jerald Feldman, Stephan J. McLain, Charles D. McLaren, and Kerwin D. Dobbs

Subjects
Photoluminescence, Aryl, 1,2,4-Triazole, chemistry.chemical_element, Electroluminescence, Dihedral angle, Ring (chemistry), Photochemistry, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, General Energy, chemistry, Iridium, Physical and Theoretical Chemistry, Phosphorescence
Abstract

Ir(III) complexes of cyclometalated 5-aryl-1H-1,2,4-triazole ligands are highly efficient, phosphorescent emitters. We describe herein a series of fac-IrL3 complexes, in which the nature of aryl substituents are shown to strongly affect emission wavelength over the range 453–499 nm. Computational and structural studies indicate that for aryl groups the point of attachment and dihedral angle with respect to the cyclometalated ring influence emission color. Significantly, this degree of color tuning may be achieved without resorting to electron-withdrawing or -donating groups. Photo- and electroluminescence device studies of the different emitters indicate that they are generally highly efficient: photoluminescent efficiencies >90% and external quantum efficiencies of up to 22% are observed.

Published
2014
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28. Structure and Dynamics of Octamethyl-POSS Nanoparticles

Author

Niina Jalarvo, Georg Ehlers, Anibal J. Ramirez-Cuesta, Sanat K. Kumar, Robert J. Smalley, Olivier Gourdon, William Guise, Michael Crawford, Kerwin D. Dobbs, Madhusudan Tyagi, and Christoph Wildgruber

Subjects
Silica nanoparticles, General Energy, Materials science, Chemical engineering, Dispersity, Nanoparticle, Molecule, Physical and Theoretical Chemistry, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Abstract

Polyoligosilsesquioxanes (POSS) are a large family of Si–O cage molecules that have diameters of 1–2 nm and can be viewed as perfectly monodisperse silica nanoparticles. POSS can be synthesized wit...

Published
2014
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29. Quality Assessment and Prediction of Philippine Mangoes: A Convolutional Neural Network Approach

Author

Robert Kerwin D. Billiones, Francisco Emmanuel T. Munsayac, Annamitz A. Rapliza, Nilo T. Bugtai, Renann G. Baldovino, and Carlos Matthew P. Cases

Subjects
Production line, Background subtraction, Speedup, General Computer Science, Artificial neural network, Computer science, business.industry, media_common.quotation_subject, Feature extraction, General Engineering, Sorting, Pattern recognition, Convolutional neural network, Quality (business), Artificial intelligence, General Agricultural and Biological Sciences, business, media_common
Abstract

Philippines is one of the world’s leading exporter of mangoes. The country produces many varieties of mangoes, one of which is the ‘Carabao’ mango. Several metric tons of mangoes are produced, and these have to be checked for defects before entering the market. With recent advances in technology, it has become efficient and relatively easy to use for these applications. The objective of this paper is to present a non-destructive method to check the quality of mangoes using computer vision (CV) and convolutional neural network (CNN) with a minimal number of samples. An experimental setup was created to simulate a production line. A webcam was used for capturing images of the mangoes, while a mini computer was used for controlling the peripherals. As basis for categorizing the mangoes as either good or bad, the Philippine National Standard (PNS) for mangoes was used. A basic background subtraction algorithm was used to extract the mango’s image. With these extracted images, a 2-category network was trained, and the achieved classification accuracy was 97.21%. The goal of having a high accuracy in classifying mangoes was achieved. There are multiple paths to explore in the future, including additional feature extraction methods, different neural networks, and hardware improvements, in order to speed up the sorting process. Moreover, it may be necessary to be able to identify mangoes with only slight defects to be used for other products, such as dried mangoes, to reduce product wastage.

Published
2019
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30. Computational Thermochemistry and Benchmarking of Reliable Methods

Author

Feller, David F., primary, Dixon, David A., additional, Dunning, Thom H., additional, Dupuis, Michel, additional, McClemore, Doug, additional, Peterson, Kirk A., additional, Xantheas, Sotiris S., additional, Bernholdt, David E., additional, Chalasinski, Grzegorz, additional, Fosada, Rubicelia, additional, Olguim, Jorge, additional, Dobbs, Kerwin D., additional, Frurip, Donald, additional, Stevens, Walter J., additional, Rondan, Nelson, additional, Chase, Jared M., additional, and Nichols, Jeffrey A., additional

Published
2006
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31. Correlating Experimental Photophysical Properties of Iridium(III) Complexes to Spin–Orbit Coupled TDDFT Predictions

Author

Kerwin D. Dobbs and Jarod M. Younker

Subjects
Angular momentum, education.field_of_study, Chemistry, Transition dipole moment, Population, Time-dependent density functional theory, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, Atomic orbital, Singlet state, Physical and Theoretical Chemistry, Atomic physics, Phosphorescence, education, Spin (physics)
Abstract

Ir(III) complexes are efficient phosphorescent emitters. The transition dipole moment between the triplet and singlet manifolds is formally spin forbidden. However, spin–orbit coupling (SOC), induced by the high angular momentum orbitals in Ir, efficiently mixes the triplet manifold with higher-energy singlets, increasing the transition probability. Spin–orbit coupled time-dependent density functional (TDDFT) calculations within the zero-order relativistic approximation (ZORA) are used to study nine complexes that have a range of emissions from 450 to 630 nm and quantum efficiencies of 0.1–0.9. We find that using the singlet ground-state geometry to calculate radiative rates produces the best correlation with experiment. We also show that the equal thermal population of the three sublevels in the triplet manifold is sufficient to understand rates at 300 K. We find that emission energies and radiative rates are best reproduced at the TD-B3LYP/TZP/DZP//BP86/TZ2P/TZP level of theory, where the larger basis s...

Published
2013
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34. Real-time viewing automated parking system

Author

Andrea R. Demegillo, Francis F. Balahadia, Orlando M. Lingo, Kenneth Bryan A. Talon, and John Kerwin D. Dizon

Subjects
Engineering, Parking guidance and information, business.industry, Computer security, computer.software_genre, GeneralLiterature_MISCELLANEOUS, System administrator, Transport engineering, Mobile phone, Proximity sensor, business, Database transaction, Smart parking, computer
Abstract

In Philippines, there is a big problem in parking because of the highly increasing number of vehicles which has a big impact in the commuters, this lead the creation of Real-Time Viewing Automated Parking System that help the parking congestion especially in mall parking and other establishment. The system uses proximity sensors for the prototype to detect the vehicles. The driver can use mobile phone to access the web application and reserve the slot for parking while the system administrator assist the transaction. This parking system can lessen the struggling on finding parking availability and tool for transportation trends.

Published
2016
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35. Reply to 'comment on 'atmospheric chemistry of linear perfluorinated aldehydes: dissociation kinetics of [C.sub.n][F.sub.2n+1]CO

Author

Waterland, Robert L. and Dobbs, Kerwin D.

Subjects
Aldehydes -- Chemical properties, Decomposition (Chemistry) -- Research, Atmospheric chemistry -- Research, Chemicals, plastics and rubber industries
Abstract

A reply to critical comment in support of strong decomposing tendency of [C.sub.n][F.sub.2n+1]CO radicals to give [C.sub.n][F.sub.2n+1] and CO under atmospheric conditions is presented.

Published
2008

36. Why excess cyanide can be detrimental to Pd-catalyzed cyanation of haloarenes. Facile formation and characterization of [[Pd[(CN).sub.3](H)].sup.2-] and [[Pd[(CN).sub.3](Ph)].sup.2-]

Author

Dobbs, Kerwin D., Marshall, William J., and Grushin, Vladimir V.

Subjects
Palladium catalysts -- Chemical properties, Cyanides -- Chemical properties, Chemistry
Abstract

Unexpected side reactions at the Pd center were identified for Pd-catalyzed cyanation of haloarenes [[Pd[(CN).sub.3](H)].sup.2-] and [[Pd[(CN).sub.3](Ph)].sup.2-]. These reactions can proceed with ease in the presence of excess cyanide, interfering with the key steps of catalytic loop and thereby disrupting the process.

Published
2007

37. 2,6-bis[2-(4-pentylphenyl)vinyl]anthracene: A stable and high charge mobility organic semiconductor with densely packed crystal structure

Author

Hong Meng, Fangping Sun, Goldfinger, Marc B., Fang Gao, Londono, David J., Dobbs, Kerwin D., Marshal, Will J., Blackman, Greg S., and Keys, Dalen E.

Subjects
Chemical synthesis -- Analysis, High-electron-mobility transistors -- Chemical properties, High-electron-mobility transistors -- Optical properties, Ultraviolet spectroscopy -- Analysis, Chemistry
Abstract

A high charge mobility and stable organic semiconductor, 2,6-bis[2-(4-pentylphenyl)vinyl]anthracene is synthesized. It is envisioned that the high charge mobility of this semiconductor is due to its densely packed crystal structure along with its well-ordered thin film morphology.

Published
2006

38. The fourth industrial fluid properties simulation challenge

Author

Fiona H. Case, John Brennan, Anne Chaka, Kerwin D. Dobbs, Daniel G. Friend, Peter A. Gordon, Jonathan D. Moore, Raymond D. Mountain, James D. Olson, Richard B. Ross, Martin Schiller, Vincent K. Shen, and Eric A. Stahlberg

Subjects
General Chemical Engineering, General Physics and Astronomy, Physical and Theoretical Chemistry
Published
2008
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40. The third industrial fluid properties simulation challenge

Author

Fiona H. Case, John Brennan, Anne Chaka, Kerwin D. Dobbs, Daniel G. Friend, David Frurip, Peter A. Gordon, Jonathan Moore, Raymond D. Mountain, James Olson, Richard B. Ross, Martin Schiller, and Vincent K. Shen

Subjects
General Chemical Engineering, General Physics and Astronomy, Physical and Theoretical Chemistry
Published
2007
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41. Atmospheric Chemistry of Linear Perfluorinated Aldehydes: Dissociation Kinetics of CnF2n+1CO Radicals

Author

Robert L. Waterland and Kerwin D. Dobbs

Subjects
Arrhenius equation, Chemistry, Radical, Kinetics, Inorganic chemistry, Decarbonylation, Ab initio, Medicinal chemistry, Quantum chemistry, symbols.namesake, Atmospheric chemistry, Yield (chemistry), symbols, Physical and Theoretical Chemistry
Abstract

Linear perfluorinated aldehydes (PFALs, CnF2n+1CHO) are important intermediate species in the atmospheric oxidation pathway of many polyfluorinated compounds. PFALs can be further oxidized in the gas phase to give perfluorinated carboxylic acids (PFCAs, CnF2n+1C(O)OH, n ) 6, 12) which have been detected in animal tissues and at low parts per billion levels in human blood sera. In this paper, we report ab initio quantum chemistry calculations of the decarbonylation kinetics of C nF2n+1CO radicals. Our results show that CnF2n+1CO radicals have a strong tendency to decompose to give CnF2n+1 and CO under atmospheric conditions: the Arrhenius activation energies for decarbonylation of CF3CO, C2F5CO, and C3F7CO obtained using PMP4/ 6-311++G(2d,p) are 8.8, 6.6, and 5.8 kcal/mol, respectively, each of which is about 5 kcal/mol lower than the barrier for the corresponding nonfluorinated radicals. The lowering of the barrier for decarbonylation of CnF2n+1CO relative to that of CnH2n+1CO is well explained by electron withdrawal by F atoms that serve to weaken the critical C-CO bond. These results have important implications for the atmospheric fate of PFALs and the atmospheric pathways to PFCAs. The main effect of decarbonylation of CnF2n+1CO is to decrease the molar yield of CnF2n+1C(O)OH; if 100% of the CnF2n+1CO decompose, the yield of CnF2n+1C(O)OH must be zero. There is considerable scope for additional experimental and theoretical studies.

Published
2007
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42. Computational Characterization of Metal Binding Groups for Metalloenzyme Inhibitors

Author

Daniel A. Kleier, Kerwin D. Dobbs, Michael Henry Howard, Amy M. Rinehart, and Ya-Jun Zheng

Subjects
Spin states, Ligand, Binding energy, Electronic structure, Combinatorial chemistry, Computer Science Applications, Metal, chemistry.chemical_compound, Peptide deformylase, chemistry, Oxidation state, visual_art, Functional group, visual_art.visual_art_medium, Physical and Theoretical Chemistry
Abstract

The mode of action of many pest or disease control agents involves inhibition of some metalloenzyme that is essential for the survival of the target organism. These inhibitors typically consist of a functional group that is capable of a primary binding interaction with the metal and a scaffold that is capable of secondary interactions with the remainder of the enzyme. To characterize the binding ability of various metal binding groups (BGs), we have performed electronic structure calculations on ligand displacement reactions in a model system related to the metalloenzyme, peptide deformylase: E-M-R + BG → E-M-BG + R. Here E represents a model coordination environment for the metal M, and R is a reference ligand (e.g., water) that may be displaced by a metal binding group. Since the oxidation state of many of the metals considered allows for multiple spin states, we also studied the influence of spin state on the coordination environment. Qualitative considerations of electronic structure inspired by the calculations provide an understanding of binding energy trends across a variety of ligands for a given metal and across a variety of metals for a given ligand.

Published
2015

43. 2-Phenylpyridine: To Twist or Not To Twist?

Author

Karl Sohlberg and Kerwin D. Dobbs

Subjects
Biphenyl, Steric effects, Aromaticity, Computer Science Applications, Ion, chemistry.chemical_compound, Crystallography, chemistry, Computational chemistry, Molecular orbital, Density functional theory, 2-Phenylpyridine, Physical and Theoretical Chemistry, Twist
Abstract

Density functional theory methods were used to investigate the structures associated with 2-phenylpyridine, ppy, and several of its electronic states. The structure of ppy has the aromatic rings twisted with respect to one another by ∼21°, which is about half the value found for biphenyl. In comparison with ppy, both the isoelectronic cation, ppyH(+), and anion, ppy(-), have larger twist angles. The extent of twisting is governed by the delicate balance between π conjugation and repulsive orbital/steric interactions, and the magnitudes of these interactions were investigated by examining the torsional energy barriers for all three molecular species. In contrast, every one of the investigated open-shell structures [Formula: see text] ppy(•)(+), ppy(•)(-), ppy*, ppyH(+)*, and ppy(-)* [Formula: see text] has coplanar aromatic rings, that is, no twist angle. Frontier molecular orbital analyses reveal that the π-type bonding between the bridging carbons becomes dominant over any repulsive orbital and steric interactions, thereby leading to coplanar rings. Also, the energetics associated with ppy and its various electronic states were investigated and reported.

Published
2006
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44. 'To Bend or not To Bend?' Both! The Planar and Bent Structures of[(Ph 3 P) 4 Rh 2 (μ‐F) 2 ]

Author

Santiago Alvarez, Vladimir V. Grushin, Gabriel Aullón, Kerwin D. Dobbs, and William J. Marshall

Subjects
chemistry.chemical_classification, Ligand, Bent molecular geometry, chemistry.chemical_element, Rhodium, Inorganic Chemistry, Metal, Crystallography, Planar, chemistry, visual_art, Intramolecular force, X-ray crystallography, visual_art.visual_art_medium, Counterion
Abstract

The first experimental evidence is presented for planar–bent isomerism of complexes of the type [L4M2(μ-X)2]. Both the planar and bent forms have been detected for the same composition, [(Ph3P)4Rh2(μ-F)2], with full exclusion of any variation in such factors as the nature of the metal, ligand, counterion, and solvent of co-crystallization. Computationalstudies point to weak C–H···F intramolecular bonding as an additional factor affecting the choice between the planar and bent geometries. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Published
2006
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45. Dynamics of molecular surface diffusion: Energy distributions and rotation–translation coupling.

Author

Dobbs, Kerwin D. and Doren, Douglas J.

Subjects
*MOLECULAR dynamics, *DIFFUSION, *SPECTRAL energy distribution, *NICKEL, *CARBON monoxide
Abstract

Surface diffusion rates have been simulated using classical molecular dynamics in a model of CO adsorbed on Ni(111). This paper describes the energy distribution among adsorbate modes at the transition state, energy relaxation after crossing the transition state, and correlations among adsorbate modes near the transition state. The adsorbate bending (frustrated rotation) mode is strongly coupled to lateral translational motion. This molecular mode provides an important source of energy for reaching the transition state to diffusion, and an important frictional force that dissipates excess lateral translational energy. In this model, the molecular bending mode is a more important source (and sink) of lateral translational energy than the surface at short times. This result is interpreted as a consequence of directional bonding to the surface, and it should be generally important in surface diffusion of chemisorbed molecules. [ABSTRACT FROM AUTHOR]

Published
1993
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46. Ab initio prediction of the barrier height for abstraction of H from CH4 by OH.

Author

Dobbs, Kerwin D., Dixon, David A., and Komornicki, Andrew

Subjects
*CHEMICAL reactions, *MOLECULAR orbitals, *GEOMETRY
Abstract

The reaction CH4+OH→CH3+H2O has been investigated by ab initio molecular orbital theory with a variety of basis sets and levels of correlation. At the highest level of basis set (Dunning’s correlation consistent) and highest level of correlation [QCISD(T)], the value of ΔH(0) is -13.44 kcal/mol and the classical barrier height is 6.62 kcal/mol which is reduced to 5.24 kcal/mol if zero point effects are included. Transition state theory is used to predict the rate constants and good agreement with the experimental values is found over a broad temperature range. [ABSTRACT FROM AUTHOR]

Published
1993
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47. Quantum chemical modeling for 157 nm photolithography

Author

Robert L. Waterland, Robert Clayton Wheland, Andrew Edward Feiring, Amy M. Rinehart, Bruce E. Smart, and Kerwin D. Dobbs

Subjects
business.industry, Chemistry, Organic Chemistry, Photoresist, Biochemistry, Quantum chemistry, Spectral line, law.invention, Inorganic Chemistry, law, Environmental Chemistry, Molecule, Optoelectronics, Density functional theory, Physical and Theoretical Chemistry, Photolithography, Absorption (electromagnetic radiation), business, Lithography
Abstract

In its continuing quest for smaller length scales, the electronics industry plans to introduce 157 nm as the next lithographic wavelength. Accordingly, there is a pressing need to develop photoresists that are more transparent, and pellicles that are both more transparent and more durable. With the advent and popularization of time-dependent density functional theory (TD-DFT), we now have a practical quantum chemical method for calculating excitation energies and transition moments in the vacuum ultraviolet (VUV) which can greatly assist in the scouting of highly transparent materials. We have performed TD-DFT calculations for a broad variety of fluorinated molecules and we will report calculated VUV photoabsorption spectra for a large family of model fluorohexanes. These calculations, which span a range from 1-fluorohexane to CH 3 CF 2 CF 2 CF 2 CF 2 CH 3 , illustrate some of the principles one may use to design low absorption polymeric materials.

Published
2003
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48. Origin of side bands in the FTIR spectrum of acetone oxime vinyl ether

Author

Karl Sohlberg and Kerwin D. Dobbs

Subjects
Infrared, Molecular electronics, Vinyl ether, Condensed Matter Physics, Photochemistry, Biochemistry, chemistry.chemical_compound, chemistry, medicine, Density functional theory, Physics::Chemical Physics, Physical and Theoretical Chemistry, Fourier transform infrared spectroscopy, Acetone oxime, medicine.drug
Abstract

The origin of two minor but enigmatic side bands in the Fourier-transform infrared spectrum (FTIR) of acetone oxime vinyl ether is resolved with density functional theory calculations. A comparison of vibrational frequencies as computed with Hartree–Fock self-consistent-field theory and density functional theory is carried out for acetone oxime vinyl ether, and N-(3-nitrobenzylidene)-p-phenylenediamine. Implications for molecular electronics are discussed.

Published
2002
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