Academic literature on the topic 'Failed DCR'
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Journal articles on the topic "Failed DCR"
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Gökçek, A., M. A. Argin, and A. K. Altintas. "Comparison of Failed and Successful Dacryocystorhinostomy by Using Computed Tomographic Dacryocystography Findings." European Journal of Ophthalmology 15, no. 5 (2005): 523–29. http://dx.doi.org/10.1177/112067210501500501.
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Purpose To compare the spiral computed tomographic dacryocystography (CT-DCG) findings of failed and successful dacryocystorhinostomies (DCR) and to detect the possible causes of failure before reoperation. Methods Eighteen patients with failed and 15 patients with functional DCR were examined by spiral CT-DCG, a combination of contrast dacryocystography and spiral computed tomography. Radiologists, who were blinded to the clinical status of the patients, measured the diameter of the osteotomy window, evaluated its position relative to the lacrimal sac, and documented any abnormal findings around the osteotomy, which may contribute to the failure of DCR. Results Location of the osteotomy window was inappropriate in 83% (15/18) of unsuccessful cases and in 7% (1/15) of successful cases and the difference was statistically significant (p<0.01). Presence of the ethmoid air cells medial to the ostium was detected to have a significantly higher frequency in the unsuccessful DCR group (78%, 14/18) than in the successful group (20%, 3/15) (p<0.01). The antero-posterior diameter of bony ostium was less than 15 mm in 94% (17/18) of failed DCR cases, but in only 60% (9/15) of successful DCR cases, and the difference was statistically significant (p<0.05). Some additional findings that may contribute to the failure were noted in failed cases. There were ethmoid sinusitis in three, concha bullosa in two, nasal polyposis in two, mass in medial canthus in one, and extensive granulation tissue around the rhinostomy in one of the failed cases. Conclusions CT-DCG is a valuable imaging tool to evaluate DCR failures before reoperation. In this series, CT-DCG showed that small size and inappropriate position of osteotomy, and also extension of ethmoid air cells medial to the lacrimal sac, were frequently seen causative factors of DCR failure.
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Sreenivas, V., P. Chaitanya, and Manjoo Reddy. "Early bi-canalicular silicone stent intubation in failed DCR with endoscopic visualization: a combined approach." International Journal of Otorhinolaryngology and Head and Neck Surgery 5, no. 3 (2019): 613. http://dx.doi.org/10.18203/issn.2454-5929.ijohns20191619.
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<p class="abstract"><strong>Background:</strong> Chronic dacryosystitis is a common condition affecting the eye and presenting to ENT surgeons and ophthalmologists, and treated with DCR (dacryocystorhinostomy). In few cases there can be recurrence of symptoms following DCR surgery which can be treated with bi-canalicular silicone intubation. The aim of this study is to assess the effectiveness of an early bi-canalicular silicone intubation in patients with failed DCR using endoscopic visualisation.</p><p class="abstract"><strong>Methods:</strong> This was a prospective observational study. Thirteen cases of DCR operated for chronic dacryocystitis at St John’s Medical College Hospital were reviewed between January 2014 and February 2017. Endoscopic DCR was done for five patients and external DCR for eight patients, number of males were 5 (38%) and females were 8 (62%). Age: 9–73 years (avg: 40.5 years). </p><p class="abstract"><strong>Results:</strong> Nine patients had complete resolution of symptoms following the primary DCR (4 following external DCR and 5 following endonasal endoscopic DCR). Four patients had failed DCR with persistence of watering three months following primary DCR surgery. Re-DCR with bi - canalicular silicon stent intubation was done in failed cases. Postoperative follow up of all the four patients showed complete resolution of symptoms.</p><p class="abstract"><strong>Conclusions:</strong> Failed DCR surgeries can be effectively intubated using bi–canlicular silicon tubes in the early postoperative period following DCR surgery. Silicone tube intubation is the most safe and cost effective method. Endoscopic visualization gives an added advantage of localizing the cause for a failed DCR.</p>
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Yu, Bo, Guang-Ming Zhou, Jie-Liang Shi, En-De Wu, and Wen-Can Wu. "Management of chronic dacryocystitis cases after failed external dacryocystorhinostomy using endoscopic technique with a novel lacrimal ostium stent." International Journal of Ophthalmology 15, no. 3 (2022): 413–19. http://dx.doi.org/10.18240/ijo.2022.03.07.
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AIM: To demonstrate the outcomes of endoscopic endonasal dacryocystorhinostomy (En-DCR) with an novel lacrimal ostium stent (LOS) which was performed in patients with recurrent epiphora after failed external dacryocystorhinostomy (Ex-DCR) and analyze the causes of failed Ex-DCR. METHODS: From September 2015 and December 2017, the clinic data of 29 cases suffered from recurrent epiphora after failed Ex-DCR was reviewed. The LOS were implanted into the ostium at the end of the revisional surgery. The causes of failed Ex-DCR were analyzed before revisional surgeries. Outcome of revisional surgeries with the new device were evaluated as well. RESULTS: The major causes of failure of the external approach were synechiae formation in the nasal ostium (29/29), followed by inadequate removal of the bony wall (21/29), nasal synechiae formation between lateral wall of nose and middle turbinate (11/29), and the bone opening was not in good location (7/29). The rate of success after revisional surgery was 82.76%. Re-obstruction of the ostiums were found in 5 failed cases. CONCLUSION: Endoscopic approach with a novel LOS may be an effective procedure to manage recurrent epiphora after previous failed Ex-DCR surgery. Synechiae formation in the nasal ostium and inadequate removal of the bony wall were the major causes of failure of Ex-DCR.
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Herzallah, Islam R., Osama A. Marglani, Sumaiya H. Muathen, and Arwa A. Obaid. "Endoscopic and Radiologic Findings in Failed Dacryocystorhinostomy: Teaching Pearls for Success." American Journal of Rhinology & Allergy 33, no. 3 (2018): 247–55. http://dx.doi.org/10.1177/1945892418815044.
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Background Although several studies have commented on causes of dacryocystorhinostomy (DCR) failure, detailed description of anatomical findings in such cases remains insufficient. Objective Our objective was primarily to analyze radiologic, endoscopic, and intraoperative findings in patients presenting with failed DCR and secondarily to assess the outcome of revision endoscopic DCR (endo-DCR) carried out at our institution. Methods Twenty-four failed DCRs presenting to our tertiary care center were retrospectively analyzed. Data collection included patients’ history, diagnostic, and management data, as well as thorough analysis of sinonasal CT scans, along with endoscopic and intraoperative findings. Outcome was also assessed in 21 cases with revision endo-DCR performed. Results The anterior part of uncinate process was not previously removed in 15 sides (62.5%), with unopened agger nasi in 13 sides (54.2%). The lacrimal bone was detected covering the posterior sac despite removal of the anterior ascending process of maxilla in 9 sides (37.5%). Rhinostoma was anterior to lacrimal sac in 2 sides (8.3%) and was below the sac in 7 sides (29.2%). Fibrous membrane covered the rhinostoma despite removal of all sac-overlying bones in 6 sides (25%). Other findings included intranasal adhesions, septal deviation, lateralized middle turbinate, granulation tissue, foreign body reaction, and chronic sinusitis. Nineteen of the 21 revision endo-DCRs were successful (90.5%). Conclusion This study provides a precise anatomical description of findings in cases of failed DCR. Such information is paramount in helping surgeons enhance their learning curve, refine the surgical technique, and improve patients’ outcome.
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Ahmed, Mohammed Naveed, Muneeruddin Ahmed S, Mahendra Kumar M, Ramakrishna Ramakrishna, Siva Prasad G, and Boddikuri Sreekanth. "CLINICAL EVALUATION OF FAILED ENDONASAL DCR OPERATIONS AND THEIR MANAGEMENT." Journal of Evolution of Medical and Dental Sciences 3, no. 48 (2014): 11526–32. http://dx.doi.org/10.14260/jemds/2014/3510.
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Letarte, François, Julie Hallet, Sébastien Drolet, et al. "Laparoscopic Emergency Surgery for Diverticular Disease That Failed Medical Treatment." Diseases of the Colon & Rectum 56, no. 12 (2013): 1395–402. http://dx.doi.org/10.1097/dcr.0b013e3182a760b6.
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Lavryk, Olga A., Luca Stocchi, Sherief Shawki, et al. "Redo IPAA After a Failed Pouch In Patients With Crohn’s Disease." Diseases of the Colon & Rectum 63, no. 6 (2020): 823–30. http://dx.doi.org/10.1097/dcr.0000000000001644.
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Poonam, Kumari Pinki, and Bhaskar Gyan. "A Hospital-Based Comparative Assessment of the Outcome of Revision External Dacryocystorhinostomy (DCR) With or Without Mitomycin C." International Journal of Pharmaceutical and Clinical Research 15, no. 3 (2023): 811–16. https://doi.org/10.5281/zenodo.12775214.
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<strong>Aim: </strong>The aim of the present study was to compare the outcome of revision external dacryocystorhinostomy (DCR) with or without mitomycin C. <strong>Methods: </strong>This prospective study was conducted on over 50 diagnosed patients with failed external dacryocystorhinostomy who arrived at the Regional Institute of Ophthalmology, IGIMS, Patna, Bihar, India for one year. <strong>Results: </strong>In 50 diagnosed patients with failed external dacryocystorhinostomy Group A underwent revision external dacryocystorhinostomy with Mitomycin–C and Group B without mitomycin–C. Maximum 40% of the patients were 41–50 age group in Group A (Mitomycin C) and 40.0% in 41-50 age group in Group B (without Mitomycin C). The mean age was 40.3±9.3 and 41.5±10.3 years in Group A and B, respectively (P = 0.800). The mean age of both groups was comparable. There were 12 (48%) males and 13 (52%) females in Group A, 10 (40%) males and 15 (60%) females in Group B. Out of 50 patients, 15 (60%) had left-sided failed dacryocystorhinostomy, and 10 (40%) had right-sided failed dacryocystorhinostom. <strong>Conclusion: </strong>Mitomycin C has a beneficial effect in preventing reclosure of the dacryocystorhinostomy stoma after revision external dacryocystorhinostomy and no significant complications resulting from its use.
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Remzi, Feza H., Victor W. Fazio, Hasan T. Kirat, James S. Wu, Ian C. Lavery, and Ravi P. Kiran. "Repeat Pouch Surgery by the Abdominal Approach Safely Salvages Failed Ileal Pelvic Pouch." Diseases of the Colon & Rectum 52, no. 2 (2009): 198–204. http://dx.doi.org/10.1007/dcr.0b013e31819ad4b6.
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Lian, Lei, Victor W. Fazio, Feza H. Remzi, Bo Shen, David Dietz, and Ravi P. Kiran. "Outcomes for Patients Undergoing Continent Ileostomy After a Failed Ileal Pouch-Anal Anastomosis." Diseases of the Colon & Rectum 52, no. 8 (2009): 1409–14. http://dx.doi.org/10.1007/dcr.0b013e3181ab586b.
Full textBooks on the topic "Failed DCR"
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Gupta, Nishi. Endoscopic Septoplasty & Mucosal preservation Conchoplasty in a failed case of DCR. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6114-4.
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Grabenwarter, Christoph, ed. Europäischer Grundrechteschutz. Nomos Verlagsgesellschaft mbH & Co. KG, 2022. http://dx.doi.org/10.5771/9783845299457.
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<b>Die Grundrechte des Unionsrechts</b> sind zentraler Bestandteil des Unionsrechts. Die Grundrechte-Charta beherrscht die Rechtsprechung der Gerichte, die Unionsrecht anwenden, allen voran des Gerichtshofes der Europäischen Union, und die wissenschaftliche Diskussion. <b>Das Handbuch Europäischer Grundrechteschutz</b> behandelt alle Grundfragen europäischer <b>Grundrechtsdogmatik</b>, die wesentlichen <b>Garantiegehalte </b>der Grundrechte-Charta und den <b>Schutz der Grundrechte vor Gericht </b>vor dem Hintergrund der Verfassungsüberlieferungen der Mitgliedstaaten. <b>Die 2. Auflage</b> berücksichtigt die umfassende neue Rechtsprechung des EGMR und des EuGH, z.B. zum Anwendungsbereich der Charta, zur rechtlichen Anerkennung gleichgeschlechtlicher Lebensgemeinschaften oder zum Justizgewährungsanspruch und einem „fairen Verfahren“. <b>Besonderer Schwerpunkt</b> liegt auf den Bereichen Fundamentalgarantien, den einzelnen Freiheits- und Bürgerrechten sowie der Durchsetzung der Grundrechte insbesondere vor Gericht. Ausgeweitet bzw. <b>neu hinzu </b>kamen in diesem Zusammenhang die Kapitel: Versammlungs- und Vereinigungsfreiheit Kunst- und Wissenschaftsfreiheit Recht auf Bildung Asylrecht und Schutz gegen Abschiebung, Ausweisung und Auslieferung Politische Bürgerrechte Grundrechte-Agentur Die Autorinnen und Autoren Prof. Dr. Marten Breuer, Prof. Dr. Marc Bungenberg, Prof. Dr. Matthias Cornils Prof. Dr. Hans-Joachim Cremer, Prof. Dr. Dr. h.c. Thomas von Danwitz, Prof. Dr. Klaus F. Gärditz, Prof. Dr. Dr. Christoph Grabenwarter, Prof. Dr. Jörg Gundel, Prof. Dr. Michael Holoubek, BVR Prof. Dr. Peter M. Huber, Prof. Dr. Jan Henrik Klement, Prof. Dr. Christine Langenfeld, PD Dr. Roman Lehner, Prof. Dr. Martin Nettesheim, Prof. Dr. Katharina Pabel, Prof. Dr. Robert Rebhahn †, Apl. Prof. Dr. Dagmar Richter, Prof. Dr. Stefanie Schmahl, Dr. Felix Schörghofer, Prof. Dr. Frank Schorkopf, Prof. Dr. Pál Sonnevend, LL.M., Hon.-Prof. Dr. Gabriel N. Toggenburg, LL.M., Prof. Dr. Robert Uerpmann-Wittzack, Prof. Dr. Christian Waldhoff, Prof. Dr. Christian Walter und Prof. Dr. Mattias Wendel.
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Day, Adam. States of Disorder, Ecosystems of Governance. Oxford University Press, 2022. http://dx.doi.org/10.1093/oso/9780192863898.001.0001.
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Today’s vision of world order is founded upon the concept of strong, well-functioning states, in contrast to the destabilizing potential of failed or fragile states. This worldview has dominated international interventions over the past thirty years as enormous resources have been devoted to developing and extending the governance capacity of weak or failing states, hoping to transform them into reliable nodes in the global order. But with very few exceptions, this project has not delivered on its promise: countries like Somalia, Afghanistan, South Sudan, and the Democratic Republic of the Congo (DRC) remain mired in conflict despite decades of international interventions. This book addresses the question, Why has United Nations (UN) statebuilding so consistently failed to meet its objectives? It proposes an explanation based on the application of complexity theory to UN interventions in South Sudan and the DRC, where the UN has been tasked to implement massive stabilization and statebuilding missions. Far from being ‘ungoverned spaces’, these settings present complex, dynamical systems of governance with emergent properties that allow them to adapt and resist attempts to change them. UN interventions, based upon assumptions that gradual increases in institutional capacity will lead to improved governance, fail to reflect how change occurs in these systems and may in fact contribute to underlying patterns of exclusion and violence. Based on more than a decade of the author’s work in peacekeeping, this book offers a systemic mapping of how governance systems work, and indeed work against, UN interventions. Pursuing a complexity-driven approach instead helps to avoid unintentional consequences, identifies meaningful points of leverage, and opens the possibility of transforming societies from within.
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Demshuk, Andrew. Total Disconnect, 1968–1988. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190645120.003.0006.
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Not only had the regime failed to seriously undermine public protest; it had also unwittingly transformed the University Church into a rallying point for public indignation. First the June 1968 unfurling of a banner demanding “reconstruction” of the University Church at the international Bach competition embodied a final act of protest before twenty years of profound cynicism and disengagement in place of the public enthusiasm of the first postwar years. Then after years of private resentment, memory of the crass injustice of 1968 helped to fuel the general disgust at urban decay and misrule, prompting the 1989 peaceful revolution in Leipzig that helped to topple the DDR regime.
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Alexandrowicz, C. H. A Treatise by J. H. G. Justi on Asian Government (1960–61). Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780198766070.003.0013.
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This chapter examines Johann Heinrich Gottlieb von Justi’s treatise entitled ‘Vergleichungen der Europäischenmit den Asiatischen und anderen vermeintlich Barbarischen Regierungen’. Justi was one of the greatest German political writers of the eighteenth century. His treatise compared the system of government as known in Europe with that prevailing in Asia, and the expression ‘Vermeintlich Barbarische Regierungen’ reflects Justi’s critical attitude towards a climate of opinion in certain European circles which looked upon Asian civilization as an inferior one. While Justi failed to employ a systematic method in the comparative exposition of European and Asian government, his views on the development of European–Asian relations are of considerable interest to the historian of the law of nations.
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Lachenal, Guillaume. The Doctor Who Would Be King. Translated by Cheryl Smeall. Duke University Press, 2022. http://dx.doi.org/10.1215/9781478022480.
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In The Doctor Who Would Be King Guillaume Lachenal tells the extraordinary story of Dr. Jean Joseph David, a French colonial army doctor who governed an entire region of French Cameroon during World War II. Dr. David—whom locals called “emperor”—dreamed of establishing a medical utopia. Through unchecked power, he imagined realizing the colonialist fantasy of emancipating colonized subjects from misery, ignorance, and sickness. Drawing on archives, oral histories, and ethnographic fieldwork, Lachenal traces Dr. David’s earlier attempts at a similar project on a Polynesian island and the ongoing legacies of his failed experiment in Cameroon. Lachenal does not merely recount a Conradian tale of imperial hubris, he brings the past into the present, exploring the memories and remains of Dr. David’s rule to reveal a global history of violence, desire, and failure in which hope for the future gets lost in the tragic comedy of power.
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Huber, Christian, Roland Kornes, Melanie Mathis, and Axel A. Thoenneßen, eds. Fachtagung Personenschaden 2019. Nomos Verlagsgesellschaft mbH & Co. KG, 2019. http://dx.doi.org/10.5771/9783748904809.
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Anliegen des im ersten Halbjahr 2019 gegründeten Instituts für faire Schadensregulierung ist es, auszuloten, was es im Detail bedeutet, dass der Schädiger bzw. die hinter ihm stehende Haftpflichtversicherung die im Gesetz vorgesehene Einbuße des Anspruchstellers auszugleichen hat. Die erste Fortbildungsveranstaltung in Berlin (7. und 8.11.2019) setzt sich zum Ziel, alle an der Regulierung von Personenschäden Beteiligten auf den neuesten Stand zu bringen und die Überzeugungskraft der gegenläufigen Argumente zu hinterfragen. Behandelt werden dabei aktuelle Themen wie der zulässige Einsatz darauf spezialisierter Dienstleister durch die Haftpflichtversicherer zur Auswertung von Belegforderungen und Datenerhebungen sowie die Beweislast im Haftpflichtprozess. Zu vier Kerngebieten erfolgt ein Überblick über die Rechtsprechung des letzten halben Jahres.
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Woodfield, Ian. Intertroupe Rivalries. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190692636.003.0001.
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Joseph II’s failed scheme to swap the Austrian Low Countries for Bavaria provoked the formation of a league of states opposed to this reconfiguration of Europe. In order to repair the damage done to his reputation in the German-speaking world, he reinstated the recently disbanded Singspiel, so that it could compete with the Italian troupe. A lighthearted contest in the Orangerie at Schönbrunn inaugurated two years of intense operatic rivalry. Thanks to Dittersdorf’s hit success Der Apotheker, which overshadowed the impact of Figaro, the German party established an early ascendancy, but the Italians struck back with an opera featuring Spanish fashion. Martín y Soler’s Una cosa rara was greeted with storms of applause at its premiere on the name day of the fiancée of Archduke Franz, second in line to the Habsburg Monarchy.
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Woloch, Nancy. Protection in Ascent, 1908–23. Princeton University Press, 2017. http://dx.doi.org/10.23943/princeton/9780691002590.003.0005.
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This chapter examines Muller's aftermath in legal history through the landmark case of Adkins v. Children's Hospital (1923). In Oregon, an employer (Children's Hospital) sought an injunction against the DC Minimum Wage Board to restrain it from imposing the minimum wage of $16.50 per week for women workers in hotels, hospitals, restaurants, clubs, and apartment houses. The District of Columbia Supreme Court upheld the law in June 1920, as did the DC Court of Appeals in June 1921. However, at the second hearing in November 1922, the DC Court of Appeals upset the law. In 1923, when Adkins v. Children's Hospital reached the Supreme Court, defenders of the minimum wage faced a less receptive roster of justices than they had in 1917; recent appointments made in wartime and soon after had produced a more conservative court. As such, the Supreme Court failed to sustain the District of Columbia minimum wage law by a 5–3 decision.
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Baker, Mark C., and Jonathan Bobalijk. On Inherent and Dependent Theories of Ergative Case. Edited by Jessica Coon, Diane Massam, and Lisa Demena Travis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780198739371.013.5.
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This chapter compares the view that ergative case is an inherent case assigned by v to an NP that it theta-marks (the ICT) to the view that ergative case is a dependent case assigned to a higher NP when there is a lower NP in the same local domain (the DCT). First we present instances in which a nonagent receives ergative case when there is another NP nearby, in applicative constructions in Shipibo, Kalaallisut (West Greenlandic), and Chukchi. Conversely, we present instances in which an agent fails to receive ergative, either because the second NP has been rendered invisible, or because the clause is subsumed within a larger case domain (ECM, causatives). Both data sets support the DCT over the ICT. Finally, we argue that no known language displays a straightforwardly active case pattern—a fact that can be explained by the DCT but not the ICT.
Book chapters on the topic "Failed DCR"
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Zielonka, Jan. "Has Liberalism Failed?" In Krise der Demokratie - Krise der Wissenschaften? Böhlau Verlag, 2020. http://dx.doi.org/10.7767/9783205233008.55.
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Haas, Antje, Thomas Mayer, Anja Tebinka-Olbrich, Maximilian Blindzellner, Elisa Beggerow, and Andreas Nickel. "Beschleunigte Zulassung von Arzneimitteln: Herausforderungen für Patient:innen, Datenqualität und faire Preise." In Arzneimittel-Kompass 2021. Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-662-63929-0_8.
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Zusammenfassung Zusammenfassung Beschleunigte Zulassungen stellen die Nutzenbewertung und Erstattung von Arzneimitteln vor besondere Herausforderungen. Der Artikel setzt sich in Form eines narrativen Reviews mit den Auswirkungen dieser Zulassungen auf Patient:innen, Angehörige der Gesundheitsberufe und die Solidargemeinschaft sowie mit den möglichen Lösungsstrategien auseinander. Die Autor:innen geben dazu anhand aktueller Literatur zunächst einen Überblick über die Zulassung von Arzneimitteln mit „conditional marketing authorisation“, „approval under exceptional circumstances“ sowie Orphan Drugs. Anschließend stellen sie den Einfluss beschleunigter Zulassungen auf die Nutzenbewertung dar und bewerten diesen. Zum Schluss beschreiben sie in diesem Zusammenhang Herausforderungen im Hinblick auf Arzneimittelpreise.
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Hendrickx, Anne, and Thomas Kanga-Tona. "Ein transparentes Modell für einen fairen Preis für innovative Arzneimittel in Europa." In Arzneimittel-Kompass 2021. Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-662-63929-0_11.
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Zusammenfassung Zusammenfassung Das empfindliche Gleichgewicht zwischen Bezahlbarkeit von Arzneimitteln, Nutzen für Gesundheitssysteme und Patient:innen sowie Einnahmen für die Pharmafirmen hat sich zugunsten letzterer eingependelt. Die europäischen Gesundheitssysteme tun sich schwer damit, Patient:innen zeitnahen Zugang zu neuartigen Arzneimitteln zu ermöglichen, weil deren hohe Preise nicht gerechtfertigt sind. Wie aber verschafft man den Patient:innen Zugang und setzt dabei gleichzeitig Anreize für die Pharmaindustrie, in neue Arzneimittel zu investieren, die die Patient:innen auch wirklich brauchen? In ihrem Modell für eine faire Preisfestsetzung in Europa plädiert die Association Internationale de la Mutualité (AIM) für eine aktivere Rolle der Preisfestsetzungs- und Erstattungsbehörden in Europa bei der Definition und Festsetzung „fairer“ Preise für innovative Arzneimittel. Alternativ zum bisherigen Value-based Pricing schlägt die AIM einen einfachen, aber effektiven Algorithmus vor, der auf die zugrunde liegenden Kosten und den therapeutischen Nutzen abstellt. Wenn man den Gewinn auf ein vernünftiges Maß beschränken und gleichzeitig relevante Innovationen honorieren würde, dann könnte man die Arzneimittelpreise senken und den Patient:innen einen besseren Zugang zu diesen Medikamenten verschaffen. Mit ihrem Modell für eine faire Preisfestsetzung in Europa leistet die AIM einen Beitrag zu einer zentralen Debatte, die die Gesundheitssysteme weltweit in den kommenden Jahren beschäftigen wird.
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Lenzen, Dieter. "Ein Welthochschulsystem fairer Chancen?" In Eine Hochschule der Welt. Springer Fachmedien Wiesbaden, 2014. http://dx.doi.org/10.1007/978-3-658-07266-7_6.
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Kaufmann, Frank. "Faires Angebot oder übles Foul?" In Grenzen der Demokratie. VS Verlag für Sozialwissenschaften, 2012. http://dx.doi.org/10.1007/978-3-531-19682-4_16.
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Kormann, Hermut. "Bindung durch faire Verfassung." In Zusammenhalt der Unternehmerfamilie. Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-16351-7_7.
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Kormann, Hermut. "Bindung durch faire Vereinbarungen." In Zusammenhalt der Unternehmerfamilie. Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/978-3-662-55943-7_7.
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Grabenwarter, Christoph. "Der Grundsatz des fairen Verfahrens." In Verfahrensgarantien in der Verwaltungsgerichtsbarkeit. Springer Vienna, 1997. http://dx.doi.org/10.1007/978-3-7091-6882-0_35.
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Wolf, Gerhard. "„Waffengleichheit“? „Fairer Prozeß“? „Gerichtliche Fürsorge“?" In Schriftenreihe der Juristischen Fakultät der Europa-Universität Viadrina Frankfurt (Oder). Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-57027-8_5.
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Meier, Frank. "Fairer Wettbewerb in Sport und Wissenschaft." In Kulturen der Gesellschaft. transcript Verlag, 2024. https://doi.org/10.14361/9783839472361-010.
Full textConference papers on the topic "Failed DCR"
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Li, Duanjiao, Zhiming Liao, Wenxing Sun, et al. "Analysis of the Reasons for the Failed 10 kV MOA Based on Impulse Aging and Power Frequency Aging Tests." In 2024 IEEE International Conference on DC Technologies and Systems (DCTS). IEEE, 2024. https://doi.org/10.1109/dcts62535.2024.10941598.
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Ferrer, Charles P., Michelle Gaudett Koul, Brian J. Connolly, and Angela L. Moran. "Utilization of Low Temperature Retrogression and Re-Aging (RRA) Heat Treatments to Improve Strength/SCC Properties for Thick Section Components of Aluminum Alloy 7075 for Aging Aircraft Refurbishment." In CORROSION 2002. NACE International, 2002. https://doi.org/10.5006/c2002-02159.
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Abstract Aluminum alloy 7075, a common material in the aerospace industry, is susceptible to intergranular stress-corrosion cracking (SCC) in the T6, or peak-aged temper. The susceptibility of this temper to SCC is alleviated through the use of the T73, or overaged temper that provides SCC resistance, but at a 10-15% strength loss compared to the T6 temper. Experimental test results by Cina and Ranish indicated that retrogress and re-aging (RRA) heat treatments with retrogression performed at 200-280°C for less than 10 minutes reduce the traditional trade-off between T6 strength and T73 SCC resistance. However, the short time heat treatment limited the applicability of RRA to thin sections of material. The primary goal of this effort was to determine if lower retrogression temperatures could be used in the RRA process to extend the applicability of this heat treatment to thick section aircraft components. Tensile, fatigue, fracture toughness, and hardness tests were conducted to characterize the mechanical properties of T6, T73, and various RRA tempers. Alternate immersion (AI) and double-cantilever beam (DCB) tests were conducted to evaluate the SCC resistance of the different tempers. Results verified that the T6 temper exhibits strengths that are ten to fifteen percent higher than the T73 temper, but has crack growth rates that are approximately ten times faster than T73. Furthermore, the T6 temper failed via environmental cracking much more quickly when subjected to 3.5% NaCl in the alternate immersion test. Improvements in properties were demonstrated using RRA heat treatments at lower temperatures and longer times than those previously investigated. In general, the various RRA tempers below 200°C produced strengths similar to that of T6 with lower crack growth rates. The RRA temper with retrogression at 160°C for 660 minutes produced the greatest improvement, with only a 4% reduction in strength below T6. Stress corrosion crack growth rates for the RRA were significantly lower than that of the T6 temper during the double-cantilever beam experiments and times to failure were substantially longer than T6 in the alternate immersion tests. Additionally, heat transfer analysis indicated the RRA tempers with lower retrogression temperatures and longer retrogression times are more viable for use in industry for thick section components.
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Sankarasubramanian, Santosh, Jaime Cruz, Kyle Yazzie, et al. "High Temperature Interfacial Adhesion Strength Measurement in Electronic Packaging Using the Double Cantilever Beam Method." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-67007.
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Advanced microelectronic packages utilize a multitude of materials with dramatically different mechanical properties. Delamination occurring at the interfaces between these materials, due to poor adhesion and/or moisture exposure, is an important failure mode affecting the thermomechanical reliability of the package. The adhesion strength of these interfaces is a critical mechanical property that plays a role in the reliability performance of these packages. A good adhesion strength metrology is required to perform material selection and enable assembly process optimization in order to avoid the need for expensive assembly builds, followed by reliability testing which leads to long development times. This paper discusses the use of the Double Cantilever Beam (DCB) method for characterizing the adhesion strength of interfaces in advanced microelectronic packages at both room and high temperatures. Previous work in this area was focused only on room temperature testing. However, in order to characterize the adhesion strength of these interfaces at elevated temperatures seen during package assembly and reliability testing, an environmental chamber was designed and fabricated to rapidly and uniformly heat the DCB samples for testing at high temperatures. Depending on the interface tested and the testing temperature, DCB samples failed in one of three fail modes: (1) adhesive (at the interface), (2) cohesive (within the adhesive layer), and (3) brittle cracking of the substrate. Two case studies describing high temperature DCB testing on silicon-capillary underfill samples are presented. With adhesive failure being the desired fail mode in order to rank order materials and processes, it was found that for the underfills tested in this study, the DCB samples failed cohesively within the underfill at room temperature but started failing adhesively at temperatures near 150°C. Adhesion strength also showed a clear degradation with temperature. It is suspected that the change in failure mode from cohesive to adhesive with increasing temperature is due to competing trends of degradation in cohesive strength of the underfill versus degradation in adhesive strength of the interface with temperature.
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Kozbial, K., R. Al-Zoairy, B. Schaefer, et al. "Retreatment of patients with chronic hepatitis C who failed interferon-free direct acting antiviral therapy." In 51. Jahrestagung & 29. Fortbildungskurs der Österreichischen Gesellschaft für Gastroenterologie & Hepatologie (ÖGGH). Georg Thieme Verlag KG, 2018. http://dx.doi.org/10.1055/s-0038-1654650.
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VICOL, Nelu. "Educația/învățarea altfel, dar... La fel?" In "Învățarea școlară în contextul provocărilor societale", simpozion științific transfrontalier. Ion Creangă Pedagogical State University, 2023. https://doi.org/10.46727/s.23-06-2023.p69-76.
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Learning plays a very important role, it is a fundamental problem of education and is the fundamental condition for the development of any individual and any society. But how to optimize learning? How to organize schools and education system? How to finance them? How to ensure the quality human resource - teachers? Regardless of how we organized, how we finance or how to drive the schools, no matter what human resources policies we apply, if we fail to optimize learning, we have done nothing. The ultimate criterion of success of any solution regarding education is, there-fore, the extent to which the solution contributes to a better learning, so to an educational environment and teachers through success.
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Luna Hinojosa, M., F. C. Duncan, N. Al Nasrallah, and C. R. Sears. "Assessment of Cigarette Smoking Patterns, Quit Attempts, and Self-reported Reasons for Failed Cigarette Smoking Abstinence." In American Thoracic Society 2023 International Conference, May 19-24, 2023 - Washington, DC. American Thoracic Society, 2023. http://dx.doi.org/10.1164/ajrccm-conference.2023.207.1_meetingabstracts.a4865.
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Lamothe, P., A. Shepherd, M. C. Runnstrom, et al. "Dupilumab as a Last Resort for Allergic Bronchopulmonary Aspergillosis, Effective Even After Other Biologics Have Failed." In American Thoracic Society 2023 International Conference, May 19-24, 2023 - Washington, DC. American Thoracic Society, 2023. http://dx.doi.org/10.1164/ajrccm-conference.2023.207.1_meetingabstracts.a3073.
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Malaieri, Mohammadreza, Raya Matoorian, and Roman J. Shor. "Time Series Analysis as an Alternative for Decline Curve Analysis in Unconventional Plays." In SPE Western Regional Meeting. SPE, 2022. http://dx.doi.org/10.2118/209261-ms.
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Abstract Quick and reliable forecasting of production data is still challenging in unconventional plays, even with the variety of modifications proposed to Arps decline curve analysis (DCA). Machine learning revealed promising results when enough samples were accessible to train and validate the predictive model. However, this black-box model is inaccurate for unseen samples, challenging to generalize, and requires too much data. We attempted to present an alternative procedure to solve this problem —a fast and reliable method outperforming current approaches. In this study, we implemented univariate and multivariate times series analysis (TSA) to forecast production rate in the different scales (wellbore, field, and pad scales) where DCA failed to provide an appropriate fit beforehand. TSA is straightforward and enables recognition of the pattern in observation samples. Cyclic fluctuation due to seasonal changes in price and operational hours can be detected and indirectly considered in time series models like ETS (Exponential Smoothing) and ARIMA (Auto-Regressive Integration Moving Average). However, for the direct considerations of these critical parameters, Vector Auto-Regressive (VAR) models have the flexibility and ability to be configured with multiple variables and can capture more complexities. This simple and quick procedure applies on any scale from the wellbore to the field scales. To evaluate the performance, the TSA method has been applied and tested on data from the Duvernay shale in Western Canada. On the wellbore scale, modified DCA models forecast production rate with over/underestimation, even where enough observations are available, and if the well has shown a declining trend in the production. In the same wells, TSA provides a better fit and outperforms the DCA. In the field and pad scales, DCA could not draw a fitting model as production had a growing trend due to ongoing field developments. In contrast, TSA could realize the trend in the production data and successfully create the forecasting model. Price and production hours were added to the time series model as influential features on production. The model could forecast all the parameters simultaneously. In sum, TSA is a reliable and flexible alternative for DCA and can be implemented on production data in any scale.
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Taibi, Hadjer, and Eemer Eivers. "Student Experiences with Continuous Assessment in DCU Futures at Dublin City University." In Tenth International Conference on Higher Education Advances. Universitat Politècnica de València, 2024. http://dx.doi.org/10.4995/head24.2024.17267.
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The COVID-19 pandemic and the arrival of generative AI have accelerated a shift towards Continuous Assessment (CA) in higher education. This paper uses data from a broader evaluation of the “Futures” initiative in Dublin City University (DCU) to explore student experiences of different forms of CA. DCU Futures aims to transform the undergraduate experience, in part by a much stronger focus on CA. Survey data from 546 DCU students were used to examine how different models of undergraduate programmes related to student satisfaction with CA. Compared to traditional exams, CA was perceived to be fairer, comprehensive, and less stressful, but a minority viewed it as less accurate. For most forms of CA, increased exposure was associated with higher satisfaction levels. Exceptions were CA formats that required groupwork. The outcomes show the importance of sharing detailed assessment rubrics with students, and of providing ongoing guidance on groupwork.
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Rudrapatna, Venkatesh K., Kimberly Morley, James P. Kushner, Andrew S. Pierson, Christian T. Shull, and Paul J. Shami. "Abstract LB-178: Phase I trial of low-dose oral clofarabine in myelodysplastic syndromes patients who have failed frontline therapy." In Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC. American Association for Cancer Research, 2013. http://dx.doi.org/10.1158/1538-7445.am2013-lb-178.
Full textReports on the topic "Failed DCR"
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Bumann, Felix, Felix Panitz, and Clemens Felsmann. Ganzheitliche Bewertung von Wärmepumpensystemen. Technische Universität Dresden, 2023. http://dx.doi.org/10.25368/2023.14.
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Es erfolgt ein ganzheitlicher Vergleich der Systeme Luftwärmepumpe und Sole-Wasser-Wärmepumpe für ein Bestandsgebäude. Für die Bewertung der Umweltfreundlichkeit bzw. Klimaschutzwirksamkeit werden die CO2-äquivalenten Treibhausgasemissionen (THG-Emissionen) und der nicht-erneuerbare Primärenergiebedarf (KEV) der Systeme bilanziert. Für den fairen Vergleich werden Systeme mit investkostengleichen Gesamtinvestitionen gebildet, indem die Luftwärmepumpe zusätzlich um eine PV-Anlage ergänzt wird.
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Söding, Emanuel. Die Dateninfrastruktur (DIS)-Erhebung im Forschungsbereich Erde und Umwelt der Helmholtz-Gemeinschaft: Erste Ergebnisse und Schlussfolgerungen. HMC Office, GEOMAR Helmholtz Centre for Ocean Research Kiel, 2022. http://dx.doi.org/10.3289/hmc_publ_06.
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Die Anschlussfähigkeit bestehender Helmholtz-Dateninfrastrukturen an nationale und internationale Initiativen (z.B. NFDI, EOSC und andere), ist ein wichtiges zentren-übergreifendes Ziel der Helmholtz- Gemeinschaft. Dafür ist es entscheidend, die bestehenden Zusammenhänge der Forschungsdaten- erhebenden und -nachnutzenden sowie die Dateninfrastrukturen (DIS) entlang der FAIR-Prinzipien1 zu ordnen. Ziel dieser Erhebung ist es, einen Überblick über bestehende Praktiken und Entwicklungs- stände der Dateninfrastrukturen (DIS) in der Helmholtz Gemeinschaft im Bereich Erde und Umwelt zu erhalten, um eine konsistente Strategie zur Umsetzung eines FAIRen Datenraumes entwickeln zu können.
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Gückelhorn, Cathrin, Olaf Struck, Matthias Dütsch, and Gesine Stephan. Bonuszahlungen an Manager : Eine Szenarienanalyse zu Gerechtigkeitsurteilen von Beschäftigten. Otto-Friedrich-Universität, 2014. http://dx.doi.org/10.20378/irb-6429.
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Bonuszahlungen im Top-Management haben in den letzten Jahren zugenommen – genauso wie die öffentliche und politische Debatte darüber. Vor diesem Hintergrund geht der Aufsatz der Frage nach, wann Beschäftigte Bonuszahlungen an Manager als gerecht bzw. ungerecht einschätzen. Hierzu greift der Artikel auf Theorien und Ansätze der empirischen organisationalen Gerechtigkeitsforschung zurück. Datengrundlage ist eine repräsentative telefonische Befragung, in der die Teilnehmenden hypothetische Szenarien in Form von Vignetten bewerteten. Die Auswertungen zeigen, dass Situationsmerkmale im Vergleich mit soziodemografischen Merkmalen der Befragten einen starken Einfluss auf die Gerechtigkeitsurteile haben. Eine korrespondierende Erfolgsbeteiligung der Belegschaft kann demnach zur Akzeptanz von Bonuszahlungen führen. Geringere Einflüsse gehen hingegen von einer Berücksichtigung der Belegschaftsinteressen bei Entscheidungen des Managements, umfangreichen Informationen, dem Unternehmenserfolg sowie der Bonushöhe aus. Die Verantwortung des Top-Managements sowie ein Hinweis auf die Branchenüblichkeit der Bonuszahlungen besitzen keinen Einfluss. Insgesamt liefert der Beitrag damit neue Erkenntnisse zu Fragen der sozialen Gerechtigkeitund gibt Anregungen zur fairen Ausgestaltung von Bonuskomponenten.
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Couture, Caroline, Jérôme Lavoué, Philippe Sarazin, Isabelle Valois, and Maximilien Debia. Substitution du dichlorométhane. IRSST, 2025. https://doi.org/10.70010/chwb3364.
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Résumé L’exposition aux solvants organiques est une préoccupation majeure en santé et en sécurité du travail. Selon CAREX Canada, 22 000 travailleuses et travailleurs canadiens étaient exposés en 2016 au dichlorométhane (DCM), incluant 5 600 travailleuses et travailleurs québécois. Le DCM est notamment utilisé comme solvant dans les décapants à peinture et les dégraissants, comme milieu réactionnel dans la synthèse de produits pharmaceutiques et de pesticides et comme solvant pour l’extraction de substances organiques. En plus de ses effets irritants et cancérogènes, le DCM peut être responsable d’une carboxyhémoglobinémie par production endogène de monoxyde de carbone lors de sa transformation métabolique. La toxicité du DCM a mené à son interdiction dans l’Union européenne dans les décapants à peinture depuis 2012 et de nouvelles réglementations se mettent en place aux États-Unis afin d’interdire ou de limiter son utilisation. Au Canada, le DCM est inscrit sur la Liste critique des ingrédients des cosmétiques de Santé Canada et son usage est interdit dans les cosmétiques en aérosols. Ces mesures forcent les entreprises à travailler au remplacement du DCM dans de nombreuses applications. C’est dans cette optique qu’une revue de littérature critique a été effectuée afin d’identifier les options de rechange au DCM. Pour ce faire, une recherche exhaustive a été réaliséedans 1) des bases de données bibliographiques; 2) des banques de données factuelles; 3) des rapports d’études de cas et 4) des fiches de substitution par utilisation. Une consultation de quatre banques de données d’exposition professionnelle a aussi été complétée afin de cibler les milieux de travail les plus préoccupants au regard de l’exposition au DCM. Deux outils d’analyse comparative ont permis d’évaluer les options de remplacement du DCM. Il s’agit du rapport de danger de vapeur (indice « Vapour Hazard Ratio » ou VHR), indiquant le potentiel de surexposition de différentes options de remplacement, ainsi que du système P2OASys (Pollution Prevention Option Analysis System) produit par le Toxics Use Reduction Institute (TURI) et permettant d’attribuer une cote aux produits chimiques selon différents critères (notamment en environnement, santé et sécurité). Finalement, les différents solvants de remplacement identifiés ont été analysés en regard du programme Safer Choice de l’U.S. EPA qui vise à informer sur le degré de vertitude des substances. Les secteurs de la réparation des avions et automobiles (fuselage et carrosserie), de la production de produits chimiques organiques industriels et de produits du plastique (incluant les produits en mousse plastique), de la fabrication et de la réparation des structures de bois (rembourrage, matelas et sommiers, mobiliers de bureau, bâtiments publics et mobiliers connexes, cloisons, luminaires, armoires de cuisine), mais aussi ceux de la fabrication d’ascenseurs et d’escaliers mobiles sont propices à engendrer des situations de surexposition. Dix-sept solvants de remplacement ont été identifiés avec à la fois un VHR ≤ 1000 et une cote P2OASys ≤ 6. Parmi ces solvants, on souligne les esters d’acides dicarboxyliques (DBE), le carbonate de propylène, le d-limonène, le lactate d’éthyle, les acétates, le diméthylsulfoxyde (DMSO), le méthylal (diméthoxyméthane), l’alcool benzylique (AB), l’isopropanol, et certains éthers de glycol. Les DBE, le lactate d’éthyle, l’isopropanol et l’acétate de propyle sont aussi des produits recommandés par le programme Safer Choice. D’autres substances présentant des enjeux plus importants en hygiène du travail, le N,N-Diméthylformamide (DMF) et la N-méthyl-2-pyrrolidone (NMP), apparaissent aussi comme des options de remplacement au DCM. Toutes ces options de remplacement ne sont pas sans danger pour les travailleuses et travailleurs, et tout projet de remplacement du DCM devrait se faire selon une démarche organisée et systématique, soit la démarche en 9 étapes proposée par Gérin et Bégin (2002).
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Phillips, Donald A., Yitzhak Spiegel, and Howard Ferris. Optimizing nematode management by defining natural chemical bases of behavior. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7587234.bard.
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This project was based on the hypothesis that nematodes interacting with plants as either parasites or beneficial saprophytes are attracted to their host by natural products. This concept was supported by numerous observations that parasitic nematodes are attracted to root exudates. Our overall goal was to identify nematode sensory compounds from root exudates and to use that information for reducing nematicide applications. We applied skills of the investigators to achieve three specific objectives: 1) Identify nematode behavioral cues (e.g., attractants or repellents) in root exudates; 2) Identify new natural nematicidal compounds; and 3) Combine a natural attractant and a nematicide into a nematode trap. Because saprophytic nematodes benefit plants by mineralizing organic matter, we sought compounds attractive primarily to parasitic nematodes. The project was constructed on several complementary foundations. First, data from Dr. Spiegel’s lab showed that under aseptic conditions Ditylenchus dipsaci, a parasite on onion, is attracted to certain fractions of onion root exudates. Second, PI Phillips had a sizeable collection of natural plant products he had identified from previous work on Rhizobium-legume interactions, which could be tested “off the shelf”. Third, Dr. Ferris had access to aseptic and natural populations of various saprophytic and parasitic nematodes. The project focused on five nematode species: D.dipsaci, Heterodera avenae, and Tylenchulussemipenetransat ARO, and Meloidogyne javanicand Caenorhabditis elegans at UCD. Ten pure plant compounds, mostly flavonoids, were tested on the various nematode species using six different assay systems. Results obtained with assorted test systems and by various scientists in the same test systems were essentially irreproducible. Many convincing, Many convincing, i.e. statistically significant, results in one system or with one investigator could not be repeated with other assays or different people. A recent report from others found that these compounds, plus another 30, were inactive as attractants in three additional parasitic nematode species (Wuyts et al. Nematology 8:89- 101, 2006). Assays designed to test the hypothesis that several compounds together are required to attract nematodes have thus far failed to find a reproducibly active combination. In contrast to results using pure plant compounds, complex unfractionated exudates from aseptic onion root reproducibly attracted D. dipsaci in both the ARO and UCD labs. Onion root exudate collection, separation into HPLC fractions, assays using D. dipsaci and MS-MS experiments proceeded collaboratively between ARO and UCD without any definitive identification of an active compound. The final active fraction contained two major molecules and traces of several other compounds. In the end, analytical studies were limited by the amount of onion root exudate and the complexity of the purification process. These tests showed that aseptic plant roots release attractant molecules, but whether nematodes influence that release, as insects trigger release of attractants from plants, is unknown. Related experiments showed that the saprophyte C. elegans stimulates its prey, Pseudomonas bacteria, to increase production of 2, 4-diacetylphloroglucinol (DAPG) a compound that promotes amino acid exudation by plant roots. It is thus possible that saprophytic nematodes are attracted primarily to their bacterial or fungal prey and secondarily to effects of those microorganisms on root exudation. These observations offer promising avenues for understanding root-zone interactions, but no direct routes to controlling nematodes in agriculture were evident. Extracts from two plant sources, Chrysanthemum coronarium and Sequoia sempervirens, showed nematicidal activity at ARO and UCD, respectively. Attempts to purify an active compound from S. sempervirens failed, but preliminary results from C. coronarium are judged to form a potential basis for further work at ARO. These results highlight the problems of studying complex movement patterns in sentient organisms like nematodes and the issues associated with natural product isolation from complex mixtures. Those two difficulties combined with complications now associated with obtaining US visas, slowed and ultimately limited progress on this project. As a result, US investigators expended only 65% of the $207,400 originally planned for this project. The Israeli side of the project advanced more directly toward its scientific goals and lists its expenditures in the customary financial report.
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Kirchhoff, Helmut, and Ziv Reich. Protection of the photosynthetic apparatus during desiccation in resurrection plants. United States Department of Agriculture, 2014. http://dx.doi.org/10.32747/2014.7699861.bard.
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In this project, we studied the photosynthetic apparatus during dehydration and rehydration of the homoiochlorophyllous resurrection plant Craterostigmapumilum (retains most of the photosynthetic components during desiccation). Resurrection plants have the remarkable capability to withstand desiccation, being able to revive after prolonged severe water deficit in a few days upon rehydration. Homoiochlorophyllous resurrection plants are very efficient in protecting the photosynthetic machinery against damage by reactive oxygen production under drought. The main purpose of this BARD project was to unravel these largely unknown protection strategies for C. pumilum. In detail, the specific objectives were: (1) To determine the distribution and local organization of photosynthetic protein complexes and formation of inverted hexagonal phases within the thylakoid membranes at different dehydration/rehydration states. (2) To determine the 3D structure and characterize the geometry, topology, and mechanics of the thylakoid network at the different states. (3) Generation of molecular models for thylakoids at the different states and study the implications for diffusion within the thylakoid lumen. (4) Characterization of inter-system electron transport, quantum efficiencies, photosystem antenna sizes and distribution, NPQ, and photoinhibition at different hydration states. (5) Measuring the partition of photosynthetic reducing equivalents between the Calvin cycle, photorespiration, and the water-water cycle. At the beginning of the project, we decided to use C. pumilum instead of C. wilmsii because the former species was available from our collaborator Dr. Farrant. In addition to the original two dehydration states (40 relative water content=RWC and 5% RWC), we characterized a third state (15-20%) because some interesting changes occurs at this RWC. Furthermore, it was not possible to detect D1 protein levels by Western blot analysis because antibodies against other higher plants failed to detect D1 in C. pumilum. We developed growth conditions that allow reproducible generation of different dehydration and rehydration states for C. pumilum. Furthermore, advanced spectroscopy and microscopy for C. pumilum were established to obtain a detailed picture of structural and functional changes of the photosynthetic apparatus in different hydrated states. Main findings of our study are: 1. Anthocyan accumulation during desiccation alleviates the light pressure within the leaves (Fig. 1). 2. During desiccation, stomatal closure leads to drastic reductions in CO2 fixation and photorespiration. We could not identify alternative electron sinks as a solution to reduce ROS production. 3. On the supramolecular level, semicrystalline protein arrays were identified in thylakoid membranes in the desiccated state (see Fig. 3). On the electron transport level, a specific series of shut downs occur (summarized in Fig. 2). The main events include: Early shutdown of the ATPase activity, cessation of electron transport between cyt. bf complex and PSI (can reduce ROS formation at PSI); at higher dehydration levels uncoupling of LHCII from PSII and cessation of electron flow from PSII accompanied by crystal formation. The later could severe as a swift PSII reservoir during rehydration. The specific order of events in the course of dehydration and rehydration discovered in this project is indicative for regulated structural transitions specifically realized in resurrection plants. This detailed knowledge can serve as an interesting starting point for rationale genetic engineering of drought-tolerant crops.
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Aly, Radi, James H. Westwood, and Carole L. Cramer. Novel Approach to Parasitic Weed Control Based on Inducible Expression of Cecropin in Transgenic Plants. United States Department of Agriculture, 2003. http://dx.doi.org/10.32747/2003.7586467.bard.
Full textAbstract:
Our overall goal was to engineer crop plants with enhanced resistance to Orobanche (broomrape) based on the inducible expression of sarcotoxin-like peptide (SLP). A secondary objective was to localize small proteins such as SLP in the host-parasite union in order to begin characterizing the mechanism of SLP toxicity to Orobanche. We have successfully accomplished both of these objectives and have demonstrated that transgenic tobacco plants expressing SLP under control of the HMG2 promoter show enhanced resistance to O. aegyptiaca and O. ramosa . Furthermore, we have shown that proteins much larger than the SLP move into Orobanche tubercles from the host root via either symplastic or apoplastic routes. This project was initiated with the finding that enhanced resistance to Orobanche could be conferred on tobacco, potato, and tomato by expression of SLP (Sarcotoxin IA is a 40-residue peptide produced as an antibiotic by the flesh fly, Sarcophaga peregrina ) under the control of a low-level, root-specific promoter. To improve the level of resistance, we linked the SLP gene to the promoter from HMG2, which is strongly inducible by Orobanche as it parasitizes the host. The resulting transgenic plants express SLP and show increased resistance to Orobanche. Resistance in this case is manifested by increased growth and yield of the host in the presence of the parasite as compared to non-transgenic plants, and decreased parasite growth. The mechanism of resistance appears to operate post-attachment as the parasite tubercles attached to the transgenic root plants turned necrotic and failed to develop normally. Studies examining the movement of GFP (approximately 6X the size of SLP) produced in tobacco roots showed accumulation of green fluorescence in tubercles growing on transformed plants but not in those growing on wild-type plants. This accumulation occurs regardless of whether the GFP is targeted to the cytoplasm (translocated symplastically) or the apoplastic space (translocated in xylem). Plants expressing SLP appear normal as compared to non-transgenic plants in the absence of Orobanche, so there is no obvious unintended impact on the host plant from SLP expression. This project required the creation of several gene constructs and generation of many transformed plant lines in order to address the research questions. The specific objectives of the project were to: 1. Make gene constructs fusing Orobanche-inducible promoter sequences to either the sarcotoxin-like peptide (SLP) gene or the GFP reporter gene. 2. Create transgenic plants containing gene constructs. 3. Characterize patterns of transgene expression and host-to-parasite movement of gene products in tobacco ( Nicotiana tabacum L.) and Arabidopsis thaliana (L.). 4. Characterize response of transgenic potato ( Solanum tuberosum L.) and tomato ( Lycopersicon esculentum Mill .) to Orobanche in lab, greenhouse, and field. Objectives 1 and 2 were largely accomplished during the first year during Dr. Aly's sabbatical visit to Virginia Tech. Transforming and analyzing plants with all the constructs has taken longer than expected, so efforts have concentrated on the most important constructs. Work on objective 4 has been delayed pending the final results of analysis on tobacco and Arabidopsis transgenic plants. The implications of this work are profound, because the Orobanche spp. is an extremely destructive weed that is not controlled effectively by traditional cultural or herbicidal weed control strategies. This is the first example of engineering resistance to parasitic weeds and represents a unique mode of action for selective control of these weeds. This research highlights the possibility of using this technique for resistance to other parasitic species and demonstrates the feasibility of developing other novel strategies for engineering resistance to parasitic weeds.