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1. Refractive Outcomes After Trabecular Micro-Bypass Stents (iStent Inject) with Cataract Extraction in Open-Angle Glaucoma

Author

Ioannidis AS, Töteberg-Harms M, Hamann T, and Hodge C

Subjects
glaucoma, cataract surgery, trabecular micro-bypass stents, astigmatism, intraocular lenses, Ophthalmology, RE1-994
Abstract

Alexandros S Ioannidis, 1, 2 Marc Töteberg-Harms, 3 Timothy Hamann, 3 Christopher Hodge 1, 4, 5 1Vision Eye Institute Blackburn South, Melbourne, VIC, Australia; 2Royal Melbourne Hospital, Melbourne, VIC, Australia; 3Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland; 4Sydney Medical School, The University of Sydney, Sydney, NSW, Australia; 5Graduate School of Health, University of Technology Sydney, Sydney, NSW, AustraliaCorrespondence: Alexandros S IoannidisVision Eye Institute Blackburn South, 156 Canterbury Road, Blackburn South, VIC 3130, AustraliaTel +61 3 9877 6288Fax +61 3 9894 2691Email alexioannidis.ai@gmail.comPurpose: Simultaneous cataract and glaucoma surgery has traditionally been challenging for the anterior segment surgeon. The introduction of minimally invasive glaucoma surgery (MIGS) in conjunction with cataract surgery appears safe and effective in lowering intraocular pressure. Although a significant visual impact leading from the combined procedure is unexpected, we aim to describe the refractive outcomes in a cohort of patients undergoing simultaneous cataract removal and iStent inject and discuss the potential implications of combined surgery in patients with co-existent glaucoma.Patients and Methods: This is a retrospective consecutive case series inclusive of patients undergoing combined femtosecond laser-assisted cataract surgery and the insertion of two trabecular micro-bypass stents (iStent inject). Visual acuity, refraction and astigmatic vector analysis were collated and analysed from the preoperative and 4 weeks postoperative visits.Results: One hundred and six eyes of 89 patients from 2 surgeons were included in the original cohort. The mean absolute difference from target refraction was 0.36 ± 0.25D. 73.9% of eyes were within ± 0.5D of the refractive target and 98.9% of eyes were within ± 1.00D. 73.8% of eyes had 0.5D or less residual refractive astigmatism following the procedure.Conclusion: We present a novel cohort of glaucoma patients undergoing combined trabecular micro-bypass stents (iStent inject) and cataract surgery achieving excellent refractive outcomes. The results of this study indicate that this second-generation device is refractively neutral.Keywords: glaucoma, cataract surgery, trabecular micro-bypass stents, astigmatism, intraocular lenses

Published
2020

2. Highly efficient and compatible shampoo for use after hair transplant

Author

Schweiger D, Schoelermann AM, Filbry A, Hamann T, Moser C, and Rippke F

Subjects
Dermatology, RL1-803
Abstract

Dorothea Schweiger,1 Andrea M Schoelermann,1 Alexander Filbry,1 Tina Hamann,1 Claudia Moser,2 Frank Rippke1 1Research and Development, Beiersdorf AG, Hamburg, Germany; 2Moser Medical, Clinics for Aesthetic Plastic Surgery, Vienna, Austria Background: Sensitive or hyperreactive skin is a common condition defined by prickling, burning, pain, and pruritus. Although this skin problem was initially described on the face, the scalp is often affected. A sensitive scalp can react with irritation to harsh surfactants or other additives which are often present in shampoos. For this reason, we developed a new rinse-off hypertolerant shampoo specifically designed for the hypersensitive and problematic scalp.Methods: The shampoo formulation is based on an extremely mild surfactant system and contains bisabolol, an anti-irritant and anti-inflammatory ingredient of chamomile. The shampoo is free of additives such as perfumes, silicones, colorants, parabens, paraffins, and betaine. Since skin can remain in a hyperreactive state after wounding, the status after hair transplantation was chosen as a model system to test the shampoo. Scalp condition and compatibility of each volunteer were analyzed by a plastic surgeon directly after hair transplant and after stitch removal. The plastic surgeons also rated whether they would recommend the further use of the test shampoo. Additionally, volunteers completed a self-assessment questionnaire.Results: Following hair transplantation, regular use of the shampoo resulted in a significant reduction in the extent of scabbing and erythema. This was confirmed by dermatological scalp examinations performed by the plastic surgeon as well as in volunteers' self-assessments. The plastic surgeon highly recommended the further use of the test shampoo after hair transplant to all study participants.Conclusion: Application of the test shampoo demonstrated excellent skin compatibility and product efficacy after hair transplant. The test shampoo significantly reduced the extent of scabs and erythema. Therefore, the shampoo is ideally suited for use after hair transplantation and for the treatment of sensitive scalp. The excellent skin compatibility is because of the mild surfactant system, the calming ingredient bisabolol, and the absence of potentially irritating ingredients.Keywords: sensitive, scalp, shampoo, bisabolol, hair transplant

Published
2015

8. Assessment of the microvasculature in poppers maculopathy

Author

Hamann, T, Wiest, M R J, Brinkmann, M, Toro, M, Fasler, K, Baur, J, Freund, K B, Zweifel, Sandrine, Hamann, T, Wiest, M R J, Brinkmann, M, Toro, M, Fasler, K, Baur, J, Freund, K B, and Zweifel, Sandrine

Abstract

PURPOSE To investigate a possible microvascular component of poppers maculopathy (PMP) using optical coherence tomography angiography (OCTA). METHODS Twelve patients suffering from poppers maculopathy were included. Health records, optical coherence tomography (OCT), and OCTA data was gathered and compared to a healthy control group (HC). PMP lesion type was determined by manifestation in OCT. OCTA-based evaluation of retinal vascular plexus and choriocapillaris (CC) was executed. Vessel density (VD) and vessel length density (VLD) in superficial and deep capillary plexus (SCP, DCP), as well as flow deficits (FD), within the foveal avascular zone (FAZ) in CC were assessed. RESULTS Median age of PMP patients was 40 (min 24; max 64) years, all male. Eleven patients presented with ellipsoid zone-type lesions; one patient showed a vitelliform-type lesion. No qualitative microvascular changes between PMP patients and HC were identified. Quantitative values for VD and VLD of SCP and DCP did not differ in between the two groups. The analysis of FDs in CC showed no deviation from PMP patients to HC. CONCLUSIONS No vascular anomalies in qualitative and quantitative analysis in OCTA were detected in PMP patients. The constitution of the CC within FAZ of PMP patients does not differ from HC when assessed as FD.

Published
2022

13. Teacher Education and Supporting Immigrant Students in the Standards-Based Education Era

Author

Hamann, T

Abstract

The author often teaches a course titled "Teaching ELLs in the Content Areas," including this past summer (2012). Acknowledging that education of English-language learners (ELLs) and immigrant education are overlapping rather than fully synonymous, students in a recent rendering of this class raised a number of interesting issues that connect to the question of what imperatives immigration creates for teacher education. One persistent theme was their sense that teachers faced a choice of being biographically responsive to students (i.e., building on students' background knowledge and paying attention to the context in which they lived) versus teaching to the standards. A second persistent concern related to Lucas and Villegas's (2010, p. 302) contention that teachers should learn (and teacher education programs should teach) how to advocate for ELLs. The author finds both these perspectives instructive but troubling. He says as educators consider how teacher education should respond to immigration, they should be guided by several principles. First, teaching to the standards does not mean teaching against or in obliviousness to student biography. Immigrant students bring understandings and background knowledge to school. The way they are going to most readily and surpassingly succeed in classrooms is if that knowledge is accessed and used by skilled teachers to help learners construct new, more advanced understandings. Additionally, it is "not" OK to "not" advocate for newcomer students. All students count. If some struggle more than others, then perhaps educators should return to one of John Dewey's dictums: If some need more support than others, then some should get more support than others. Democracy has more of a need to assist those currently faring poorly than those who are doing just fine. Of course, successful education of immigrants entails more than just these two points, but these seem like an important place to start.

Published
2012

19. Current status of the multinational Arabidopsis community

Author

Parry, Geraint, Provart, Nicholas J., Brady, Siobhan M., Uzilday, Baris, Adams, K., Araújo, W., Aubourg, S., Baginsky, S., Bakker, E., Bärenfaller, K., Batley, J., Beale, M., Beilstein, M., Belkhadir, Y., Berardini, T., Bergelson, J., Blanco-Herrera, F., Brady, S., Braun, Hans-Peter, Briggs, S., Brownfield, L., Cardarelli, M., Castellanos-Uribe, M., Coruzzi, G., Dassanayake, M., Jaeger, G.D., Dilkes, B., Doherty, C., Ecker, J., Edger, P., Edwards, D., Kasmi, F.E., Eriksson, M., Exposito-Alonso, M., Falter-Braun, P., Fernie, A., Ferro, M., Fiehn, O., Friesner, J., Greenham, K., Guo, Y., Hamann, T., Hancock, A., Hauser, M.-T., Heazlewood, J., Ho, C.-H., Hõrak, H., Huala, E., Hwang, I., Iuchi, S., Jaiswal, P., Jakobson, L., Jiang, Y., Jiao, Y., Jones, A., Kadota, Y., Khurana, J., Kliebenstein, D., Knee, E., Kobayashi, M., Koch, M., Krouk, G., Larson, T., Last, R., Lepiniec, L., Li, S., Lurin, C., Lysak, M., Maere, S., Malinowski, R., Maumus, F., May, S., Mayer, K., Mendoza-Cozatl, D., Mendoza-Poudereux, I., Meyers, B., Micol, J.L., Millar, H., Mock, H.-P., Mukhtar, K., Mukhtar, S., Murcha, M., Nakagami, H., Nakamura, Y., Nicolov, L., Nikolau, B., Nowack, M., Nunes-Nesi, A., Palmgren, M., Parry, G., Patron, N., Peck, S., Pedmale, U., Perrot-Rechenmann, C., Pieruschka, R., Pío-Beltrán, J., Pires, J.C., Provart, N., Rajjou, L., Reiser, L., Reumann, S., Rhee, S., Rigas, S., Rolland, N., Romanowski, A., Santoni, V., Savaldi-Goldstein, S., Schmitz, R., Schulze, W., Seki, M., Shimizu, K.K., Slotkin, K., Small, I., Somers, D., Sozzani, R., Spillane, C., Srinivasan, R., Taylor, N., Tello-Ruiz, M.-K., Thelen, J., Tohge, T., Town, C., Toyoda, T., Uzilday, B., Peer, Y.V.D., Wijk, K., Gillhaussen, P.V., Walley, J., Ware, D., Weckwerth, W., Whitelegge, J., Wienkoop, S., Wright, C., Wrzaczek, M., Yamazaki, M., Yanovsky, M., Žárský, V., Zhong, X., Biological Systems Engineering, Organisms and Environment Research Division, Cardiff School of Biosciences, Cardiff University, University of Toronto, University of California [Davis] (UC Davis), University of California, Institut de Recherche en Horticulture et Semences (IRHS), Université d'Angers (UA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany, Department of Ecology and Evolution [Chicago], University of Chicago, Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Unité de recherche en génomique végétale (URGV), Institut National de la Recherche Agronomique (INRA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Rothamsted Research, Biotechnology and Biological Sciences Research Council (BBSRC), University of Arizona, Gregor Mendel Institute (GMI) - Vienna Biocenter (VBC), Austrian Academy of Sciences (OeAW), University of California (UC), Center for Genomics and Systems Biology, Department of Biology [New York], New York University [New York] (NYU), NYU System (NYU)-NYU System (NYU)-New York University [New York] (NYU), NYU System (NYU)-NYU System (NYU), Flanders Institute for Biotechnology, National Center for Atmospheric Research [Boulder] (NCAR), Max Planck Institute of Molecular Plant Physiology (MPI-MP), Max-Planck-Gesellschaft, Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Agricultural Sustainability Institute and Department of Neurobiology, Physiology, and Behavior, Norwegian University of Science and Technology (NTNU), University of Melbourne, King Abdullah University of Science and Technology (KAUST), University of Chinese Academy of Sciences [Beijing] (UCAS), The Sainsbury Laboratory [Norwich] (TSL), IBM Research – Tokyo, University Medical Center Groningen [Groningen] (UMCG), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre for Novel Agricultural Products, Department of Biology, University of York [York, UK], Biologie des Semences (LBS), Institut National de la Recherche Agronomique (INRA)-Institut National Agronomique Paris-Grignon (INA P-G), Sichuan University [Chengdu] (SCU), Institut des Sciences des Plantes de Paris-Saclay (IPS2 (UMR_9213 / UMR_1403)), Université d'Évry-Val-d'Essonne (UEVE)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Department of Plant Systems Biology, Unité de Recherche Génomique Info (URGI), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Nottingham, UK (UON), Institute of Bioinformatics and System Biology (IBIS), Helmholtz Zentrum München = German Research Center for Environmental Health, Saint Mary's University [Halifax], Max Planck Institute for Plant Breeding Research (MPIPZ), National Institute of Genetics (NIG), University of Copenhagen = Københavns Universitet (UCPH), Division of Biology [La Jolla], University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), Earlham Institute [Norwich], Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association, University of Missouri [Columbia] (Mizzou), University of Missouri System, Institut Jean-Pierre Bourgin (IJPB), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Department of Plant Biology, Carnegie Institution for Science, Dynamique du protéome et biogenèse du chloroplaste (ChloroGenesis), Physiologie cellulaire et végétale (LPCV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Plateforme de Spectrométrie de Masse Protéomique - Mass Spectrometry Proteomics Platform (MSPP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Plant Systems Biology, Institute of Physiology and Biotechnology of plants, RIKEN Center for Sustainable Resource Science [Yokohama] (RIKEN CSRS), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Unité de recherche Génétique et amélioration des plantes (GAP), Institut National de la Recherche Agronomique (INRA), Department of Biology, Duke University, Genetics and Biotechnology Lab, Plant & AgriBiosciences Research Centre (PABC), School of Natural Sciences, National University of Ireland [Galway] (NUI Galway), Universidade Federal de São Paulo, RIKEN Plant Science Center and RIKEN Bioinformatics and Systems Engineering Division, Cold Spring Harbor Laboratory (CSHL), University of Vienna [Vienna], University of California [Los Angeles] (UCLA), Department of Plant Molecular Biology, Université de Lausanne = University of Lausanne (UNIL), UKRI-BBSRC grant BB/M004376/1, HHMI Faculty Scholar Fellowship, Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) 118Z137, UK Research & Innovation (UKRI) Biotechnology and Biological Sciences Research Council (BBSRC) BB/M004376/1, Sainsbury Lab, Norwich Research Park, Université d'Évry-Val-d'Essonne (UEVE)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Helmholtz-Zentrum München (HZM), University of Copenhagen = Københavns Universitet (KU), University of California-University of California, Carnegie Institution for Science [Washington], Université de Lausanne (UNIL), Ege Üniversitesi, Organismal and Evolutionary Biology Research Programme, Plant Biology, Viikki Plant Science Centre (ViPS), Receptor-Ligand Signaling Group, University of Zurich, Parry, Geraint, Provart, Nicholas J, and Brady, Siobhan M

Subjects
0106 biological sciences, Arabidopsis thaliana, [SDV]Life Sciences [q-bio], White Paper, Genetics and Molecular Biology (miscellaneous), Plant Science, Biochemistry, 01 natural sciences, Dewey Decimal Classification::500 | Naturwissenschaften::580 | Pflanzen (Botanik), Research community, Arabidopsis, 1110 Plant Science, 0303 health sciences, Ecology, biology, 1184 Genetics, developmental biology, physiology, ddc:580, Multinational corporation, MAP, 590 Animals (Zoology), Life Sciences & Biomedicine, Arabidopsis research community, Evolution, Steering committee, Multinational Arabidopsis Steering Committee, Library science, 1301 Biochemistry, Genetics and Molecular Biology (miscellaneous), Biochemistry, Genetics and Molecular Biology (miscellaneous), Business and Economics, 10127 Institute of Evolutionary Biology and Environmental Studies, 03 medical and health sciences, Behavior and Systematics, Political science, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, MASC, roadmap, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, [SDV.GEN]Life Sciences [q-bio]/Genetics, Plant Sciences, Botany, 15. Life on land, 11831 Plant biology, biology.organism_classification, White Papers, collaboration, 1105 Ecology, Evolution, Behavior and Systematics, QK1-989, Arabidopsis Thaliana, Collaboration, Research Network, Roadmap, 570 Life sciences, 1182 Biochemistry, cell and molecular biology, 2303 Ecology, 010606 plant biology & botany
Abstract

The multinational Arabidopsis research community is highly collaborative and over the past thirty years these activities have been documented by the Multinational Arabidopsis Steering Committee (MASC). Here, we (a) highlight recent research advances made with the reference plantArabidopsis thaliana; (b) provide summaries from recent reports submitted by MASC subcommittees, projects and resources associated with MASC and from MASC country representatives; and (c) initiate a call for ideas and foci for the "fourth decadal roadmap," which will advise and coordinate the global activities of the Arabidopsis research community., UKRI-BBSRC grant [BB/M004376/1]; HHMI Faculty Scholar Fellowship; Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [118Z137], UKRI-BBSRC grant, Grant/Award Number: BB/M004376/1; HHMI Faculty Scholar Fellowship; the Scientific and Technological Research Council of Turkey, Grant/Award Number: 118Z137

Published
2020

22. A Novel Quantitative Assessment Method of Disease Activity in Susac's Syndrome Based on Ultra-Wide Field Imaging.

Author

Hamann, T., Wiest, M., Innes, W., and Zweifel, S.

Subjects
*FLUORESCENCE angiography, *OPTICAL coherence tomography, *RETINAL blood vessels, *QUANTITATIVE research, *ANGIOGRAPHY
Abstract

Susac's syndrome (ScS) is a rare, potentially life-threatening auto-immune disease. Ophthalmic imaging can depict characteristic branch retinal arteriolar occlusions (BRAO) and arterial wall hyperfluorescences that form one of the three diagnostic pillars of this condition. We aim to demonstrate that ophthalmological ultrawide-field (UWF) imaging allows for a qualitative and quantitative assessment in ScS, with application in diagnostics, monitoring of treatment response, and titration of therapy. In seven ScS patients (♀:♂ = 2:5), with a median age of 36 years, range 18 to 57 years, serial ultrawide-field fluoresceine angiography (UWF-FA) studies were performed, with adjunctive wide-field optical coherence tomography angiography analyses (WF-OCTA) in five patients. Mean follow-up was 12.5 months, range 1 to 46 months. In all seven patients, BRAO and arterial wall hyperfluorescences were present in UWF-FA and calculated as a quantitative score of disease activity in fluorescein angiography (DA-FA) during follow-up visits. Treatment response was accessible in follow-up imaging as partial reperfusion of retinal vessels, resolution of arterial wall hyperfluorescences and consequently, in reduction of DA-FA score. While qualitative analysis of WF-OCTA provided further information about retinal micro-perfusion, quantitative analysis did not demonstrate a vectored treatment response as it was accessible in FA. DA-FA score, as a comprehensive disease activity parameter in ScS has potential to facilitate optimal communication between subspecialties and thereby treatment success. [ABSTRACT FROM AUTHOR]

Published
2022
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27. Langzeitverlauf von lamellären Makulaforamen und Pseudoforamen mit einer Beobachtungszeit von mindestens fünf Jahren

Author

Treumer, F, Purtskhvanidze, K, Balken, L, Hamann, T, Wöster, L, von der Burchard, C, and Roider, J

Subjects
ddc: 610, 610 Medical sciences, Medicine
Abstract

Hintergrund: Evaluierung der funktionellen und morphologischen Langzeitveränderungen von lamellären Makulaforamen und Pseudoforamen mit oder ohne Vitrektomie und Membran-Peeling. Methode: Retrospektiv wurden 73 Augen mit lamellären Makulaforamen (LH, n=28), Pseudoforamen (PH, [zum vollständigen Text gelangen Sie über die oben angegebene URL], 68. Tagung der Vereinigung Norddeutscher Augenärzte (VNDA)

Published
2018
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31. Osmosensitive Changes of Carbohydrate Metabolism in Response to Cellulose Biosynthesis Inhibition1[W][OA]

Author

Wormit, A., Butt, M.S., Chairam, I., McKenna, J.F., Nunes-Nesi, A., Kjaer, L., O’Donnelly, K., Fernie, A.R., Woscholski, R., Barter, L.M.C., and Hamann, T.

Subjects
Time Factors, Arabidopsis Proteins, Cell Survival, Arabidopsis, food and beverages, Membrane Proteins, NADPH Oxidases, Receptors, Cell Surface, Genes, Plant, Polyethylene Glycols, Enzyme Activation, Gene Expression Regulation, Plant, Osmotic Pressure, Benzamides, Carbohydrate Metabolism, Photosynthesis, Cellulose, Reactive Oxygen Species, Protein Kinases, Bioenergetics and Photosynthesis, Plant Proteins, Signal Transduction
Abstract

Cellulose is the most abundant biopolymer in the world, the main load-bearing element in plant cell walls, and represents a major sink for carbon fixed during photosynthesis. Previous work has shown that photosynthetic activity is partially regulated by carbohydrate sinks. However, the coordination of cellulose biosynthesis with carbohydrate metabolism and photosynthesis is not well understood. Here, we demonstrate that cellulose biosynthesis inhibition (CBI) leads to reductions in transcript levels of genes involved in photosynthesis, the Calvin cycle, and starch degradation in Arabidopsis (Arabidopsis thaliana) seedlings. In parallel, we show that CBI induces changes in carbohydrate distribution and influences Rubisco activase levels. We find that the effects of CBI on gene expression and carbohydrate metabolism can be neutralized by osmotic support in a concentration-dependent manner. However, osmotic support does not suppress CBI-induced metabolic changes in seedlings impaired in mechanoperception (mid1 complementing activity1 [mca1]) and osmoperception (cytokinin receptor1 [cre1]) or reactive oxygen species production (respiratory burst oxidase homolog DF [rbohDF]). These results show that carbohydrate metabolism is responsive to changes in cellulose biosynthesis activity and turgor pressure. The data suggest that MCA1, CRE1, and RBOHDF-derived reactive oxygen species are involved in the regulation of osmosensitive metabolic changes. The evidence presented here supports the notion that cellulose and carbohydrate metabolism may be coordinated via an osmosensitive mechanism.

Published
2012

32. Titanium incorporation into hematite photoelectrodes : theoretical considerations and experimental observations

Author

Kronawitter, C. X., Zegkinoglou, I., Shen, S. -H, Liao, P., Cho, I. S., Zandi, O., Liu, Y. -S, Lashgari, Koroush, Westin, Gunnar, Guo, J. -H, Himpsel, F. J., Carter, E. A., Zheng, X. L., Hamann, T. W., Koel, B. E., Mao, S. S., Vayssieres, L., Kronawitter, C. X., Zegkinoglou, I., Shen, S. -H, Liao, P., Cho, I. S., Zandi, O., Liu, Y. -S, Lashgari, Koroush, Westin, Gunnar, Guo, J. -H, Himpsel, F. J., Carter, E. A., Zheng, X. L., Hamann, T. W., Koel, B. E., Mao, S. S., and Vayssieres, L.

Abstract

A theoretical and experimental perspective on the role of titanium impurities in hematite (alpha-Fe2O3) nanostructured photoelectrodes for solar fuel synthesis devices is provided. Titanium incorporation is a known correlate to efficiency enhancement in alpha-Fe2O3 cc photoanodes for solar water oxidation; here the relevant literature and the latest advances are presented and various proposed mechanisms for enhancement are contrasted. Available experimental evidence suggests that Ti incorporation increases net electron carrier concentrations in electrodes, most likely to the extent that (synthesis-dependent) charge compensating cation vacancies are not present. However, electron conductivity increases alone cannot quantitatively account for the large associated photoelectrochemical performance enhancements. The magnitudes of the effects of Ti incorporation on electronic and magnetic properties appear to be highly synthesis-dependent, which has made difficult the development of consistent and general mechanisms explaining experimental and theoretical observations. In this context, we consider how the electronic structure correlates with Ti impurity incorporation in alpha-Fe2O3 a from the perspective of synchrotron-based soft X-ray absorption spectroscopy measurements. Measurements are performed on sets of electrodes fabricated by five relevant and unrelated chemical and physical techniques. The effects of titanium impurities are reflected in the electronic structure through several universally observed spectral characteristics, irrespective of the synthesis techniques. Absorption spectra at the oxygen K-edge show that Ti incorporation is associated with new oxygen 2p-hybridized states, overlapping with and distorting the known unoccupied Fe 3d-O 2xp band of alpha-Fe2O3. This is an indication of mixing of Ti s and d states in the conduction band of alpha-Fe2O3. cc A comparison of spectra obtained with electron and photon detection shows that the effects of Ti incorpor

Published
2014
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33. Titanium incorporation into hematite photoelectrodes: theoretical considerations and experimental observations

Author

Kronawitter, C. X., primary, Zegkinoglou, I., additional, Shen, S.-H., additional, Liao, P., additional, Cho, I. S., additional, Zandi, O., additional, Liu, Y.-S., additional, Lashgari, K., additional, Westin, G., additional, Guo, J.-H., additional, Himpsel, F. J., additional, Carter, E. A., additional, Zheng, X. L., additional, Hamann, T. W., additional, Koel, B. E., additional, Mao, S. S., additional, and Vayssieres, L., additional

Published
2014
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34. Genetic and Genomic Analysis of Rhizoctonia solani Interactions with Arabidopsis; Evidence of Resistance Mediated through NADPH Oxidases

Author

Foley, R., Gleason, C., Anderson, J., Hamann, T., Singh, Karambir, Foley, R., Gleason, C., Anderson, J., Hamann, T., and Singh, Karambir

Abstract

Rhizoctonia solani is an important soil-borne necrotrophic fungal pathogen, with a broad host range and little effective resistance in crop plants. Arabidopsis is resistant to R. solani AG8 but susceptible to R. solani AG2-1. A screen of 36 Arabidopsis ecotypes and mutants affected in the auxin, camalexin, salicylic acid, abscisic acid and ethylene/jasmonic acid pathways did not reveal any variation in response to R. solani and demonstrated that resistance to AG8 was independent of these defense pathways. The Arabidopsis Affymetrix ATH1 Genome array was used to assess global gene expression changes in plants infected with AG8 and AG2-1 at seven days post-infection. While there was considerable overlap in the response, some gene families were differentially affected by AG8 or AG2-1 and included those involved in oxidative stress, cell wall associated proteins, transcription factors and heat shock protein genes. Since a substantial proportion of the gene expression changes were associated with oxidative stress responses, we analysed the role of NADPH oxidases in resistance. While single NADPH oxidase mutants had no effect, a NADPH oxidase double mutant atrbohf atrbohd resulted in an almost complete loss of resistance to AG8, suggesting that reactive oxidative species play an important role in Arabidopsis's resistance to R. solani.

Published
2013

36. A comparison of paraffin and resin-based techniques used in bark anatomy

Author

Hamann, T., Smets, E.F. (Erik), Lens, F. (Frederic), Hamann, T., Smets, E.F. (Erik), and Lens, F. (Frederic)

Abstract

Bark anatomy is an unappreciated discipline in plant systematics, despite its great potential to reveal systematically informative features. In this paper, main reasons for the lack of detailed bark anatomical data in many plant families are identified, including problems with sectioning, terminological issues, and difficulties in observation of dilated stems. We deal with these problems by focusing on two aspects: (1) compare, discuss and improve existing sectioning and maceration techniques using two species with soft and hard bark tissues; and (2) discuss the best way to collect stem bark samples. We hope that this paper will stimulate inclusion of bark anatomical data in future systematic studies.

Published
2011

38. The wood anatomy of the polyphyletic Icacinaceae s.l., and their relationships within asterids

Author

Lens, F. (Frederic), Kårehed, J., Baas, P. (Pieter), Jansen, S., Rabaey, D., Huysmans, S., Hamann, T., Smets, E.F. (Erik), Lens, F. (Frederic), Kårehed, J., Baas, P. (Pieter), Jansen, S., Rabaey, D., Huysmans, S., Hamann, T., and Smets, E.F. (Erik)

Abstract

Wood samples from 53 species belonging to 41 genera of the Icacinaceae s.l. are investigated using light and scanning electron microscopy. The traditionally circumscribed Icacinaceae fall apart into four segregate families that are clearly nested within asterids, i.e., Icacinaceae s.str. (near or in Garryales), Cardiopteridaceae and Stemonuraceae (both Aquifoliales), and Pennantiaceae (Apiales). From a wood anatomical point of view, these families cannot easily be distinguished from each other. However, some features such as vessel distribution, perforation plate morphology, size and arrangement of vessel pits, fibre wall thickness, and the occurrence of cambial variants can be used to assign various species to one of the four families. The wood structure of the four segregate families is in general agreement with their suggested putative relatives, but the occurrence of lianas versus erect trees and shrubs is a confusing factor in getting clear phylogenetic signal from the wood structure. Maximum parsimony and Bayesian analyses using molecular data and combined anatomical-molecular data show that Icacinaceae s.str. are not monophyletic, and their closest relatives remain unclear. The combined analyses provide moderate support for a clade including Cassinopsis, the Apodytes-group, the Emmotum-group (all Icacinaceae s.str.), and the genus Oncotheca. This clade is situated at the base of lamiids and may be closely related to Garryales. The remaining lineage of Icacinaceae s.str., the Icacina-group represented by many climbing taxa exhibiting cambial variants, is strongly supported and might be sister to the rest of lamiids.

Published
2008

42. AtPIN4 mediates sink-driven auxin gradients and root patterning in Arabidopsis

Author

Pattern and polarity in Arabidopsis root development, Universiteit Utrecht, Dep Biologie, Friml, J., Benkova, E., Blilou, I., Wisniewska, J., Hamann, T., Ljung, K., Woody, S., Sandberg, G., Scheres, B.J.G., Jurgens, G., Palme, K., Pattern and polarity in Arabidopsis root development, Universiteit Utrecht, Dep Biologie, Friml, J., Benkova, E., Blilou, I., Wisniewska, J., Hamann, T., Ljung, K., Woody, S., Sandberg, G., Scheres, B.J.G., Jurgens, G., and Palme, K.

Published
2002

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