264 research outputs found
Characterization and application of novel chemical tools to control folding and amyloid formation
No full textSSVLaboratory of Molecular Neurobiology and Functional Neuroproteomics, EPFL. - Supervision: Awad Loay. - External Expert : Catherine Servis, PhD Department of Biochemistry, Unil, Lausanne, EPF
2026: Ruth Awad
No full textRuth Awad is a Lebanese-American disabled poet, a 2021 NEA Poetry fellow, and the author of Outside the Joy (Third Man Books, 2024) and Set to Music a Wildfire (Southern Indiana Review Press, 2017), winner of the 2016 Michael Waters Poetry Prize and the 2018 Ohioana Book Award for Poetry. Her work can be found in The Atlantic, AGNI, Poetry, Poem-a-Day, The Believer, The New Republic, and elsewhere. She has an MGA in poetry from Southern Illinois University Carbondale, and she lives and writes in Columbus, Ohio.https://thekeep.eiu.edu/lionsinwinter_writers/1055/thumbnail.jp
Synthesis of a C-linked disaccharide analogue of the Thomsen Friedenreich (TF)-epitope a-O-conjugated to L-serine and formation of a cluster as potential anticancer vaccine
No full textCell surface glycoproteins and glycolipids are responsible for cellular recognition processes. Vaccination is the procedure whereby the immune system is induced to create antibodies against a foreign molecule involved in disease or viral infection. In many disease states, the oligosaccharide chains presented on cell surface glycoprotein are altered. In some tumors, the glycan chains of glycoproteins are attenuated to only a few sugar residues. In the case of the TF-antigen, the polysaccharide chains have been shortened to a galactose-β-(1–>3)-N-acetyl-galactosamine disaccharide structure α-linked to a serine or threonine. Immunogenicity of this epitope in synthetic vaccines has been demonstrated. However, this disaccharide conjugate is relatively short-lived in the blood stream because of its hydrolysis catalysed by ubiquitous glycosidases in vivo. C-disaccharides are sugar mimetics whose interglycosidic linkage is non-hydrolysable as required for a disaccharide-based vaccine. In the first part of the work, we report the first synthesis of TF-antigen analogues applying the methodology developed by our group for the synthesis of C(1–>3)-disaccharides. Conjugate addition of diethylaluminium iodide (Et2AlI) to isolevoglucosenone leads to an aluminium enolate, which reacts with the sugar derived carbaldehyde, 2,6-anhydro-3,4,5,7-tetrakis-O-[(tert-butyldimethyl)silyl]-D-glycero-L-manno-heptose, to give an aldol. The convergent and stereoselective synthesis of this adduct allows us to obtain C(1–>3)-disaccharides. Reduction of the moiety derived from isolevoglucosenone with lithium borohydride, followed by cleavage of the 1,6-anhydro bridge produces C-disaccharides with D-galacto configuration. Königs-Knorr glycosidation of N-Fmoc-serine tert-butylester, followed by reduction of azide moiety to the corresponding acetamido group allows us to obtain TF-antigen analogues linked either by hydroxymethano (-CH(OH)-) or methano (-CH2-) group. In a second part we report the synthesis of a fully deprotected thio-glycotripeptide based on the TFantigen -C-analogues linked by hydroxymethano - N-acetyl-O-{α-D-glyco}-D-seryl-O-{α-D-glyco}-D-seryl-rac-N-(3-[(acetylthio)amino]propyl)-O-{α-D-glyco}-D-serinamide, which was covalently conjugated to the KLH protein carrier via Michael addition reaction. Biological trials with the TF (analogues)-KLH are in progress. We report also the synthesis of fully deprotected TF-antigen -C-analogues linked by hydroxymethano (-CH(OH) and methano (-CH2-) group. their conformational analysis is currently in progress
Synthesis of C-linked and glycopeptide towards non-hydrozable T epitopes and artificial Anticancer Vaccines
No full textSCGCDIPLOMES; GR - 53 333; ICO; . Consultable sur demande à la Bibliothèque de l'EPFL / Offered in consultation at the EPFL library
Synthesis of chemical tools to improve water solubility and promote the delivery of salinomycin to cancer cells
No full textChemotherapy and radiation are unable to eliminate all cancer cells, particularly apoptosis-resistant cancer cells, despite their ability to kill cancer cluster cells. Thus, it is important to identify methods that eliminate all cancer cells in order to prevent relapse. Salinomycin has the ability to control and eradicate different types of cancer, including breast cancer; however, its molecular mechanism remains unclear. The main difficulty in testing salinomycin activity and understanding the governing mechanisms is its low solubility in water (17 mg/l), which can hinder convenient delivery of salinomycin to the protein receptor at the cell surface of stem cells. In the present study, salinomycin was conjugated to the trans-activator of transcription-protein in order to facilitate its delivery to the cancer cells. Conjugated salinomycin demonstrated improved solubility in both in vitro. Salinomycin was tested in breast cancer cells (MCF7 and JIMT-1) by the cleavage of the linker through photolysis at l >= 365 nm during in vitro analysis, in the present study.LMN
Multicomponent image segmentation using a genetic algorithm and artificial neural network
No full textImage segmentation is an essential process for image analysis. Several methods were developed to segment multicomponent images, and the success of these methods depends on several factors including 1) the characteristics of the acquired image and 2) the percentage of imperfections in the process of image acquisition. The majority of these methods require a priori knowledge, which is difficult to obtain. Furthermore, they assume the existence of models that can estimate its parameters and fit to the given data. However, such a parametric approach is not robust, and its performance is severely affected by the correctness of the utilized parametric model. In this letter, a new multicomponent image segmentation method is developed using a nonparametric unsupervised artificial neural network called Kohonen's self-organizing map (SOM) and hybrid genetic algorithm (HGA). SOM is used to detect the main features that are present in the image; then, HGA is used to cluster the image into homogeneous regions without any a priori knowledge. Experiments that are performed on different satellite images confirm the efficiency and robustness of the SOM-HGA method compared to the Iterative Self-Organizing DATA analysis technique (ISODATA). © 2007 IEEE.ARIA EH, 2004, P 20 ISPRS C IST TUR, P117; AWAD M, IN PRESS INT J REMOT; BACAO F, 2005, P ICCS 2005 C, P476; Baker J. E., 1987, P 2 INT C GEN ALG, P14; CHEN Q, 2004, LECT NOTES COMPUT SC, V33, P621; Chun DN, 1996, PATTERN RECOGN, V29, P1195, DOI 10.1016-0031-3203(95)00148-4; Fauzi M., 2003, P BRIT MACH VIS C, P519; HOLLLAND J, 1975, ADAPT NATURAL ARTIFI; HUAPT R, 2004, PRACTICAL GENETIC AL; Jensen J. R., 1996, INTRO DIGITAL IMAGE; Kohavi R., 1998, APPL MACHINE LEARNIN, V30, P271; Levine M. D., 1985, VISION MAN MACHINE; NEVATIA R, 1980, COMPUT VISION GRAPH, V13, P257, DOI 10.1016-0146-664X(80)90049-0; Ng SC, 1996, IEEE SIGNAL PROC MAG, V13, P38, DOI 10.1109-79.543974; PARZEN E, 1962, ANN MATH STAT, V33, P1065, DOI 10.1214-aoms-1177704472; PERKINS S, 2000, FUZZY SYST EVOL COMP, V3, P52; Pina P, 2003, INT GEOSCI REMOTE SE, P3516; PRATT W, 1991, DIGITA IMAGE PROCESS; Tou J.T., 1974, PATTERN RECOGNITION; Wang X., 2004, P IEEE C ROB AUT MEC, P991; Xiaoying Jin, 2003, Proceedings of the 12th IEEE International Conference on Fuzzy Systems (Cat. No.03CH37442); Xu BG, 2002, AATCC REV, V2, P42; Yao KC, 2000, PATTERN RECOGN, V33, P1575, DOI 10.1016-S0031-3203(99)00135-1; YIN HJ, 1995, NEURAL COMPUT, V7, P1178, DOI 10.1162-neco.1995.7.6.117834232
The sorption of ammonia on brown coal
No full text© 1978 Dr. Awad Rizk OussaThis thesis is a report of an investigation carried out by the author between 1st April 1969 to 31st October 1973 on a full time basis and from 1st December 1975 to 31st July 1978 on a part time basis. The research project was conducted by the author in the Department of Chemical Engineering, University of Melbourne, and on the premises of Australian Char Pty. Ltd., Morwell.
The project was based on the premise that useful information on the brown coal-ammonia system can be obtained from sorption isotherms. The author designed and assembled the apparatus with this in mind, and developed a method of obtaining a self-consistent and meaningful interpretation of the sorption isotherms. Thermodynamic data for the ammonia sorption process was derived and used to develop a preliminary model for the ammonia-brown coal system.
No separate literature review has been presented in the thesis, though frequent reference to the literature has been made in the discussions in each chapter.
Finally, the experimental details have been included in the appendices at the end of the thesis
The game changer. Hur AI förändrar undervisning i biologi.
No full textSammanfattning
Syftet med detta arbete har varit att analysera hur implementering av AI i gymnasieskolan har påverkat biologiundervisningen utifrån lärarens samt elevens perspektiv. Studien har undersökt hur AI:s ökade närvaro i undervisningen påverkar elevers lärandeförmåga samt på vilket sätt AI kan assistera läraren i biologiundervisningen. Relevant litteratur har samlats in från olika sökmotorer och databaser utifrån blocksökningar samt osystematiska sökningar. Litteraturen som användes i arbetet har varit kopplat till biologiundervisningen men även berört andra naturvetenskapliga ämnen till följd av brist på forskning. De senare har sedan härletts till specifikt biologiundervisningen. Inledningsvis presenteras en definition av AI samt dess historiska bakgrund. Därefter presenteras den svenska skolan strategi för att implementera digitala verktyg i undervisningen utifrån gymnasieskolans styrdokument. I resultatet presenteras olika AI-redskap som kan påverka både lärare och elever positivt. Utifrån lärarens perspektiv presenteras litteratur som visar på hur AI kan fungera som ett effektiviserande redskap och kan avlasta lärare från vissa arbetsuppgifter. AI kan även individanpassa undervisningen för varje elev. Dock presenteras även risker med användandet av AI som exempelvis mer belastningen för läraren beroende på implementering samt hämmande av elevernas kreativitet och ökad risk för fusk. I slutsatsen görs flera kopplingar till biologiundervisningen. Det poängteras även att AI med största sannolikhet kommer att finnas kvar inom biologiundervisningen i framtiden och utvecklas ytterligare. Den viktigaste aspekten för en lyckad implementering av AI i undervisningen är att lärare har rätt och tillräcklig kompetens om AI samt har rätt inställning och ett intresse för det. Slutligen poängterar studien att vidare forskning inom området biologi och AI i undervisning behöver utföras för att öka kunskapen om ämnet.The purpose of this work has been to analyze how the implementation of AI in high school has affected biology education from the perspectives of both teachers and students. The study has examined how the increased presence of AI in education affects students' learning ability and how AI can assist the teacher in biology education. Relevant literature has been gathered from various search engines and databases through both block searches and unsystematic searches. The literature used in the work has been related to biology education but has also touched on other natural science subjects due to a lack of research. The latter has then been extrapolated to specifically focus on biology education. Initially, a definition of AI and its historical background is presented. Then, the Swedish school's strategy for implementing digital tools in education is presented based on the high school's official documents. The results present various AI tools that can positively impact both teachers and students. From the teacher's perspective, literature is presented that shows how AI can function as an efficiency tool and can relieve teachers from certain tasks. AI can also personalize education for each student. However, risks of using AI are also presented, such as increased workload for the teacher depending on the implementation and inhibiting students' creativity, as well as an increased risk of cheating. In the conclusion, several connections to biology education are made. It is emphasized that AI is likely to remain in biology education in the future and continue to evolve. The most important aspect for a successful implementation of AI in education is that teachers have the right and sufficient competence in AI and have the right attitude and interest in it. Finally, the study emphasizes the need for further research in the field of biology and AI in education to increase knowledge on the subject. And one last thing. This text has been translated with chatGPT
Superconducting properties of zinc substitution in Tl-2223 phase
No full textThe effect of partial replacement of copper by zinc in Tl2Ba2Ca2Cu3O10-δ superconductor phase is studied. Superconducting samples of the nominal composition Tl2Ba2Ca2Cu3-xZnx O10-δ with x ranging from 0 to 0.6 are prepared under normal pressure by a one step of solid-state reaction technique. The samples are characterized by using X-ray powder diffraction, scanning electron microscope (SEM) and EDX. The X-ray data indicate that the partial replacement of Cu2+ions by Zn2+ions does not influence the tetragonal structure of the samples, and the lattice parameters a and c vary according to the difference in the ionic radii of Cu and Zn. The superconducting parameters, such as superconducting transition temperature Tc, critical current density Jc and irreversibility field Bir are calculated from electrical resistivity and AC-magnetic susceptibility measurements. © 2007 Elsevier B.V. All rights reserved.Abou-Aly A.I., 2002, INT C RES TRENDS SCI, V91; ADACHI S, 1990, PHYSICA C, V111, P543; Awad R, 2000, PHYSICA C, V341, P685, DOI 10.1016-S0921-4534(00)00650-X; Awad R, 2007, SUPERCOND SCI TECH, V20, P401, DOI 10.1088-0953-2048-20-4-017; Awad R, 2001, PHYSICA B, V307, P72, DOI 10.1016-S0921-4526(01)00971-1; Batista-Leyva AJ, 2003, SUPERCOND SCI TECH, V16, P857, DOI 10.1088-0953-2048-16-8-305; BEAN CP, 1964, REV MOD PHYS, V36, P31, DOI 10.1103-RevModPhys.36.31; BERKLEY DD, 1993, PHYS REV B, V47, P5524, DOI 10.1103-PhysRevB.47.5524; CHEN DX, 1990, PHYSICA C, V167, P317, DOI 10.1016-0921-4534(90)90349-J; Chu SY, 2000, PHYSICA C, V337, P229, DOI 10.1016-S0921-4534(00)00107-6; Fradina IA, 1999, PHYSICA C, V311, P81, DOI 10.1016-S0921-4534(98)00563-2; Glowacki BA, 1997, CRYOGENICS, V37, P609, DOI 10.1016-S0011-2275(97)00053-2; HAZEN RM, 1988, PHYS REV LETT, V60, P1657, DOI 10.1103-PhysRevLett.60.1657; Isber S, 2005, SUPERCOND SCI TECH, V18, P311, DOI 10.1088-0953-2048-18-3-018; Isber S, 2006, J PHYS CONF SER, V43, P450, DOI 10.1088-1742-6596-43-1-112; Kayed TS, 2003, CRYST RES TECHNOL, V38, P946, DOI 10.1002-crat.200310118; Kuhberger M, 2003, PHYSICA C, V390, P263, DOI 10.1016-S0921-4534(03)00706-8; LEE MW, 1995, PHYSICA C, V245, P6, DOI 10.1016-0921-4534(95)00100-X; Mezzetti E, 2000, PHYSICA C, V332, P115, DOI 10.1016-S0921-4534(00)00008-3; MOHAMMED NH, 2005, ARAB INT C REC ADV P, P9; Nishida A, 2003, PHYSICA C, V392, P349, DOI 10.1016-S0921-4534(03)00848-7; Pavard S, 1999, PHYSICA C, V316, P198, DOI 10.1016-S0921-4534(99)00259-2; Ravi S, 2000, PHYSICA C, V330, P58, DOI 10.1016-S0921-4534(99)00611-5; REN ZF, 1991, PHYSICA C, V184, P24, DOI 10.1016-0921-4534(91)91496-Q; RUCKENSTEIN E, 1989, MATER LETT, V8, P421, DOI 10.1016-0167-577X(89)90065-7; Tang H, 1997, PHYSICA C, V282, P2111, DOI 10.1016-S0921-4534(97)01171-4; Triscone G, 1996, PHYSICA C, V264, P233, DOI 10.1016-0921-4534(96)00262-6; VANDERAH TA, 1992, CHEM SUPERCONDUCTOR, P90; WANG YB, 1993, J LOW TEMP PHYS, V15, P169; WESTERHOLT K, 1989, PHYS REV B, V39, P11680, DOI 10.1103-PhysRevB.39.11680; Wisniewski A, 2000, PHYS REV B, V61, P791, DOI 10.1103-PhysRevB.61.791; XU YW, 1990, PHYSICA C, V169, P205, DOI 10.1016-0921-4534(90)90177-G; Yamauchi H, 1998, SUPERCOND SCI TECH, V11, P1006, DOI 10.1088-0953-2048-11-10-022; Yang Li, 1994, Physics Letters A, V18543
Progressive image transmission using edge detection
No full textIn this paper, a progressive image compression and transmission using edge detection scheme is adopted. The image is decomposed into two (primary and secondary) components. Canny method is adopted to detect the edges of the encoded image. These edges are replaced with a pre-designed nine basis nameplates. Then, the Macro edge detection technique is used to reduce the number of these nameplates and keep only the edges that are necessary for visual quality.
Eight directional predictions and interpolation technique will be performed on the encoded edges to reconstruct the first layer of the primary component at both receiver and transmitter sides. This is called the 1st stage reconstructed image, which is subtracted from the original to have the 1st stage smooth component. Then, this process will be repeated for the 2nd and the 3rd stage components.
The 3rd stage smooth component is filtered using an optimal decomposition filter and then decimated by a factor of 2. The decimated component is encoded using VQ. The decoded result of the smooth image is added to the three layers that form the primary component to have the reconstructed image. An excellent reconstructed images are found at an average of 0.179 bpp (compression ratio 45:1) and with an average PSNR of 39.45 dB. This algorithm is found to be of lower bit rate than existing image compression techniques.Corresponding Author:
Prof. Awad Kh. Al-Asmari
Electrical Engineering Department
College of Engineering in Al-Kharj, King Saud University, Riyadh 11421, Saudi Arabia
E-mail: [email protected]
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