Academic literature on the topic 'Biochemical Study'

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Journal articles on the topic "Biochemical Study"

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SATOH, CHIYOKO. "Biochemical Genetics Study." Journal of Radiation Research 32, SUPPLEMENT (1991): 378–84. http://dx.doi.org/10.1269/jrr.32.supplement_378.

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Kumar L., Pradeep, Harish S. Permi, Murthy Srinivasa V., and Yadavalli Guruprasad. "Study of Biochemical Parameters in Pregnancy Induced Hypertension (PIH)." Indian Journal of Pathology: Research and Practice 5, no. 2 (2016): 191–94. http://dx.doi.org/10.21088/ijprp.2278.148x.5216.21.

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Rutkowski, Tom, Jacob Waples, Jim Gusek, and Brad Shipley. "BIOCHEMICAL REACTOR MEDIA CHARACTERIZATION STUDY." Journal American Society of Mining and Reclamation 2010, no. 2 (June 30, 2010): 888–913. http://dx.doi.org/10.21000/jasmr10010888.

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O, A. "A BIOCHEMICAL STUDY ON HEMOGLOBIN." Mansoura Veterinary Medical Journal 11, no. 1 (June 1, 2009): 1–10. http://dx.doi.org/10.21608/mvmj.2009.159561.

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ALSAWAF, Reem N., and Mohammed A. H. ALOBEADY. "Biochemical Enzymatic Study of Infertility." Eurasia Proceedings of Health, Environment and Life Sciences 6 (December 14, 2022): 24–30. http://dx.doi.org/10.55549/ephels.38.

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This study dealt with the issue of unexplained infertility in men, as it included the measurement of many biochemical variables in the semen plasma, where all of the variables total cholesterol, albumin, thiol group, manganese and zinc were measured TAC. where the results showed the presence of many significant differences between the measured variables when comparing the disease group With the control group, which indicates the different effects of these variables on patients with unexplained infertility. Also, during this study, the effect of hyaluronidase enzyme was followed up and studied by studying the activity of the enzyme as well as the purification stages of the enzyme and estimating the approximate molecular weight using the technique of gel filtration, ion exchange and electro-migration technique (SDS) This enzyme plays a pivotal role in the fertilization process, and any difference in the effectiveness of this enzyme leads to cases of unexplained infertility.
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Arroyo, A., P. Rosel, and T. Marron. "Cerebrospinal fluid: postmortem biochemical study." Journal of Clinical Forensic Medicine 12, no. 3 (June 2005): 153–56. http://dx.doi.org/10.1016/j.jcfm.2004.11.001.

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Naik, Krishna Kumar, and Shivaprasad Shivaprasad. "A Study on Biochemical Parametrs in Patients with Rickettsial Infection." Academia Journal of Medicine 2, no. 2 (July 24, 2019): 46–50. http://dx.doi.org/10.21276/ajm.2019.2.2.13.

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Sivaprasad. S, Sivaprasad S. "A Practical Approach to Study Circadian Biochemical Rhythms in Animals." Indian Journal of Applied Research 4, no. 7 (October 1, 2011): 552–54. http://dx.doi.org/10.15373/2249555x/july2014/176.

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Sayed, Ramadan Hashem, Kamal-Eldin A. Abou-Elhamd, Mohamed Abdel-Kader, and Tahia Hashem Saleem. "Study of surfactant level in cases of primary atrophic rhinitis." Journal of Laryngology & Otology 114, no. 4 (April 2000): 254–59. http://dx.doi.org/10.1258/0022215001905508.

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The surfactant system of the nose was examined biochemically in control cases and compared to cases of primary atrophic rhinitis. The study group included 25 cases with primary atrophic rhinitis compared to 10 normal volunteers. Biochemical analysis of the nasal aspirate in these cases revealed the presence of phospholipids constituting surfactant with phosphatidylcholine constituting 75.35 per cent of the total phospholipids. Biochemical analysis of the nasal aspirate in cases with primary atrophic rhinitis revealed a significant decrease in the total phospholipids compared to normal cases and also a significant change in the phospholipid profile. Thus significant biochemical changes in the surfactant system of the nose is an evident and early finding in cases of primary atrophic rhinitis. This suggests a possible role for surfactant deficiency in the aetiopathogenesis of cases of primary atrophic rhinitis.
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Nair, Dr Neena. "Impact of Nickel Chloride on Wistar Rat Epididymis: A Biochemical Study." Indian Journal of Applied Research 4, no. 6 (October 1, 2011): 528–30. http://dx.doi.org/10.15373/2249555x/june2014/165.

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Dissertations / Theses on the topic "Biochemical Study"

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Paton, F. M. "Biochemical studies of marine fungi." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382060.

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Nabi, A. "Immobilized bioluminescent reagents in flow injection analysis." Thesis, University of Hull, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381888.

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Khan, M. R. "Phytochemical study of some Costa Rican plants." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381696.

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Yi, X. "Immunological and biochemical studies on Schistosoma mansoni surface antigens." Thesis, University College London (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378926.

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Freije, Afnan Mahmood. "A biochemical study of thyroid hormone antibodies." Thesis, University of Surrey, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277595.

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Osborne, Leisa Jane. "Characterisation of Thioredoxin Dimers: A Biochemical Study." Thesis, Griffith University, 2011. http://hdl.handle.net/10072/365531.

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In addition to the conserved active site cysteines that are responsible for the classical redox activity of thioredoxins (Trx’s), vertebrate Trx’s contain an additional three conserved cysteines at position 62, 69 and 73. These structural cysteines are known to be subjected to a variety of post translational modifications including dimerisation that are believed to contribute to the regulation and diversity of function of vertebrate Trx’s. Reports of the formation of “disulphide linked dimers” have been a long standing observation since the earliest studies on vertebrate Trx’s, however detailed studies on dimerisation have been limited in number and the extent of characterisation achieved. Despite the potential for a diversity of dimeric forms with different structural and functional properties there has been a common assumption arising from the literature (despite some evidence to the contrary) that all dimers so far described are much the same and all are redox inactive.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Physical Science
Science, Environment, Engineering and Technology
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Guise, Andrew David. "A biochemical engineering study of lysozyme refolding." Thesis, University of Bath, 1996. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337816.

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Mojumdar, Aditya. "Structural and Biochemical study of human RECQ4." Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/11141.

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2013/2014
RecQ helicases belong to a ubiquitous family of DNA unwinding enzymes that are essential to maintain genome stability by acting at the interface between DNA replication, recombination and repair. Humans have five different paralogues of RecQ helicases namely RecQ1, BLM, WRN, RecQ4 and RecQ5. This work focuses on the structural and biochemical study of human RecQ4. Germ-line mutations in the RECQ4 gene give rise to three distinct human genetic disorders (Rothmund-Thomson, RAPADILINO and Baller-Gerold syndromes). Despite the important roles of RecQ4 in various cellular processes, RecQ4 have never been fully characterized. In addition to the helicase domain, RecQ4 has a unique N-terminal part that is essential for viability and is constituted by a region homologous to the yeast Sld2 replication initiation factor, followed by a cysteine-rich region, predicted to fold as a Zn knuckle. A part of this work focuses on the structural and biochemical analysis of both the human and Xenopus RecQ4 cysteine-rich regions, and shows by NMR spectroscopy that the Xenopus fragment does indeed assumes the canonical Zn knuckle fold, whereas the human sequence remains unstructured, consistent with the mutation of one of the Zn ligands. Both the human and Xenopus Zn knuckles bind to a variety of nucleic acid substrates, with a preference for RNA. We also investigated the effect of an additional Sld2 homologous region upstream the Zn knuckle. In both the human and Xenopus system, the presence of this region strongly enhances binding to nucleic acids. These results reveal novel possible roles of RecQ4 in DNA replication and genome stability. Recently the catalytic core of RecQ4 has been predicted to include RecQ-like-C-terminal (RQC) domain at the C-terminus of the helicase domain, similar to other RecQ helicases. This domain is composed of a Zn-binding region and a winged helix (WH) domain. Another part of this thesis centers on the structural and biochemical characterization of the catalytic core of RecQ4 including the helicase and RQC domain. The results provide an insight in the Zn binding ligands present in the RQC domain that plays a role in DNA binding and unwinding activity of the protein. Also the presence of the characteristic aromatic residue at the tip of the WH β hairpin and its role in DNA binding and unwinding has been established. Finally, it provides a low resolution SAXS model of the catalytic core of RecQ4.
Elicasi RecQ appartengono a una famiglia ubiquitaria di DNA svolgimento enzimi che sono essenziali per mantenere la stabilità del genoma agendo all'interfaccia tra replicazione del DNA, ricombinazione e riparazione. Gli esseri umani hanno cinque diversi paralogues di RecQ elicasi cioè RecQ1, BLM, WRN, RecQ4 e RecQ5. Questo lavoro si concentra sullo studio strutturale e biochimica di RecQ4 umana. Mutazioni germinali nel gene RECQ4 danno luogo a tre malattie genetiche umane distinte (Rothmund-Thomson, RAPADILINO e sindromi Baller-Gerold). Nonostante i ruoli importanti di RecQ4 in diversi processi cellulari, RecQ4 non sono mai stati pienamente caratterizzato. In aggiunta al dominio elicasi, RecQ4 ha una parte unica N-terminale che è essenziale per la vitalità ed è costituito da una regione omologa al lievito Sld2 fattore di iniziazione replica, seguita da una regione ricca di cisteina, previsto per piegare come stinco Zn . Una parte di questo lavoro si concentra sull'analisi strutturale e biochimica sia della regioni ricche di cisteina Xenopus RecQ4 umana e, e spettacoli di spettroscopia NMR che il frammento Xenopus effettivamente assume la canonica Zn nocca volte, mentre la sequenza di resti umani non strutturato, coerente con la mutazione di uno dei ligandi Zn. Sia il nocche Xenopus Zn umana e si legano ad una varietà di substrati di acido nucleico, con una preferenza per l'RNA. Abbiamo anche studiato l'effetto di un ulteriore regione omologa Sld2 monte la nocca Zn. Sia il sistema Xenopus umano e, la presenza di questa regione migliora fortemente legame ad acidi nucleici. Questi risultati rivelano possibili ruoli nuovi di RecQ4 nella replicazione del DNA e la stabilità del genoma. Recentemente il nucleo catalitico di RecQ4 stato previsto per includere RecQ-like-C-terminale (RQC) dominio al C-terminale del dominio elicasi, simile ad altri elicasi RecQ. Questo dominio è costituito da una regione-Zn vincolanti e un'elica alato (WH) dominio. Un'altra parte di questa tesi incentrata sulla caratterizzazione strutturale e biochimica del nucleo catalitico della RecQ4 compreso il elicasi e il dominio RQC. I risultati forniscono una descrizione nel Zn ligandi presenti nel dominio RQC che svolge un ruolo nel legame al DNA e l'attività svolgimento della proteina legante. Inoltre è stata stabilita la presenza della caratteristica residuo aromatico sulla punta della forcella WH β e il suo ruolo nel legame al DNA e di svolgimento. Infine, esso fornisce una bassa risoluzione SAXS modello del nucleo catalitico di RecQ4.
XXVII Ciclo
1985
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Asante, Emmanuel A. "Biochemical genetics of lipid metabolism in chickens and mice." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/11520.

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Zhang, Jing. "Biochemical Study and Technical Applications of Fungal Pectinase." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6295.

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Books on the topic "Biochemical Study"

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Zerizer, Sakina. Comparative biochemical study of peroxidase assay systems. Salford: University of Salford, 1987.

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Siersema, Peter Derk. The liver in uroporphyria: A biochemical and morphological study. [s.l.]: [s.n.], 1993.

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Farnsworth, Andrew Philip Haydon. A biochemical and biological study of yttrium-90 radiolabelled antibodies. Birmingham: University of Birmingham, 1990.

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Maunders, Michelle Joanne. The Epstein-Barr virus nuclear antigens: A biochemical and functional study. Birmingham: University of Birmingham, 1994.

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Kim, Sang-gyŏm. Saenghwahakchŏk pʻyojija mit taeri kyŏlgwa pyŏnsu ŭi PK/PD modelling chŏgyong e kwanhan yŏnʼgu =: The study for evaluation of PK/PD modeling using biomarker and surrogate endpoint. [Seoul]: Sikpʻum Ŭiyakpʻum Anjŏnchʻŏng, 2007.

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Dahllöf, Goran. Phenytoin-induced gingival overgrowth in epileptic children: A clinical, histological and biochemical study. Stockholm: Department of Pedodontics, School of Dentistry, Karolinska Institutet, 1986.

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Page, Lisa Jacqueline. Formate-dependent nitrite reduction in Escherichia coli: A physiological, biochemical and genetic study. Birmingham: University of Birmingham, 1991.

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Yŏm, Yŏng-il. Chŏnsachʻe pʻŭropʻail ŭl iyong han hang tangnyo chagyong kijŏn kŏmjŭng yŏnʼgu =: Study of the action mechanism of anti-diabetic drugs by transcriptome profiling. [Seoul]: Sikpʻum Ŭiyakpʻum Anjŏnchʻŏng, 2007.

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Huengsberg, Mia. Investigation of biochemical abnormalities in HIV associated neurological diseases - a prospective and retrospective study. Birmingham: University of Birmingham, 1998.

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George, Poste, and Crooke Stanley T, eds. New frontiers in the study of gene functions. New York: Plenum Press, 1987.

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Book chapters on the topic "Biochemical Study"

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Jian, Chen, and Lun Shi-Yi. "Study on Scale-Up of UASB Reactor." In Biochemical Engineering for 2001, 796–99. Tokyo: Springer Japan, 1992. http://dx.doi.org/10.1007/978-4-431-68180-9_212.

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Takamatsu, Hiroyuki, and Michiyuki Tokashiki. "Study of Hybridoma Cells’ Kinetics in High Density Culture." In Biochemical Engineering for 2001, 315–18. Tokyo: Springer Japan, 1992. http://dx.doi.org/10.1007/978-4-431-68180-9_84.

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Wibowo, Djoko, G. Budiyanto, L. Jan, and J. C. Liu. "Kinetic Study of Lysine Fermentation in Cane Molasses Base Medium." In Biochemical Engineering for 2001, 201–3. Tokyo: Springer Japan, 1992. http://dx.doi.org/10.1007/978-4-431-68180-9_53.

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Sherratt, H. S. A., N. J. Watmough, M. A. Johnson, and D. M. Turnbull. "Methods for Study of Normal and Abnormal Skeletal Muscle Mitochondria." In Methods of Biochemical Analysis, 243–336. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2006. http://dx.doi.org/10.1002/9780470110546.ch6.

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Weuster-Botz, D., and A. A. de Graaf. "Reaction engineering methods to study intracellular metabolite concentrations." In Advances in Biochemical Engineering/Biotechnology, 75–108. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/bfb0102333.

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Hoffmann, Julia, Renja Romey, Christine Fink, and Thomas Roeder. "Drosophila as a Model to Study Metabolic Disorders." In Advances in Biochemical Engineering/Biotechnology, 41–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/10_2013_196.

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Tao, Zhang, Chen Jiang-An, Wu Xing, and Zhang Ke-Chang. "A Study of Ethanol Fermentation Using a Flocculent Strain of Zymomonas mobilis." In Biochemical Engineering for 2001, 771–72. Tokyo: Springer Japan, 1992. http://dx.doi.org/10.1007/978-4-431-68180-9_206.

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Arakawa, Tsutomu, Yoshiko A. Kita, and Linda O. Narhi. "Protein-Ligand Interaction as a Method to Study Surface Properties of Proteins." In Methods of Biochemical Analysis, 87–125. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2006. http://dx.doi.org/10.1002/9780470110560.ch2.

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Jr., Jan Hermans. "Methods for the Study of Reversible Denaturation of Proteins and Interpretation of Data." In Methods of Biochemical Analysis, 81–111. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2006. http://dx.doi.org/10.1002/9780470110317.ch3.

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Tinoco, Ignacio, and Charles R. Cantor. "Application of Optical Rotatory Dispersion and Circular Dichroism to the Study of Biopolymers." In Methods of Biochemical Analysis, 81–203. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2006. http://dx.doi.org/10.1002/9780470110362.ch3.

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Conference papers on the topic "Biochemical Study"

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"Colorectal cancer study using biochemical mechanisms of inflammation." In International Conference on Medicine, Public Health and Biological Sciences. CASRP Publishing Company, Ltd. Uk, 2016. http://dx.doi.org/10.18869/mphbs.2016.36.

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Wang, Chunhong, Yue Zhou, Hongxia Zhao, Jiashi Sun, and Fengkun Zhou. "Study on color difference estimation method of medicine biochemical analysis." In ICO20:Illumination, Radiation, and Color Technologies, edited by Dazun Zhao, M. R. Luo, and Hirohisa Yaguchi. SPIE, 2006. http://dx.doi.org/10.1117/12.668070.

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Huang, Hsiao-Ying Shadow, Brittany N. Balhouse, and Siyao Huang. "A Biomechanical and Biochemical Synergy Study of Heart Valve Tissue." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-87997.

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The function of heart valves is to allow blood to flow through the heart smoothly and to prevent retrograde flow of blood. Previous studies have shown that the mechanical properties of heart valve tissues, microstructures of extracellular matrix, and collagen concentrations are the keys to the healthy heart valves and, therefore, are crucial to the development of viable tissue-engineered heart valve replacements. Therefore, this study investigates the relationship between these factors in native porcine aortic and pulmonary valves and provides insights to the healthy heart valves. Heart valve leaflets are prepared for biaxial stretching to obtain mechanical properties. The average collagen concentrations of heart valve leaflets are determined via an assay kit. The results indicate that aortic valves are stiffer than pulmonary valves macroscopically and stiffness varies more in the circumferential direction for the aortic valve than it does for the pulmonary valve. Microscopically, it is due to collagen fibers in aortic valves are more in alignment than ones in pulmonary valves, which are more randomly in direction. Collagen assay results show that collagen concentrations are higher in the edges of pulmonary valves than in aortic valves. The results also suggest the duration of extraction may have significant affects on the concentration results. This work provides quantified stress and strain environment within heart valve tissues to help further studies on how to treat heart valve disease and create more viable heart valve replacements.
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Chaibakhsh, Ali, Naz Chaibakhsh, and Mohd Basyaruddin Abdul Rahman. "Fuzzy modeling and optimization of biochemical processes: A case study." In 2010 International Conference on Chemistry and Chemical Engineering (ICCCE). IEEE, 2010. http://dx.doi.org/10.1109/iccceng.2010.5560350.

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Sabri, Laith S., Abbas J. Sultan, and Muthanna H. Al-Dahhan. "Assessment of RPT calibration need during microalgae culturing and other biochemical processes." In 2017 International Conference on Environmental Impacts of the Oil and Gas Industries: Kurdistan Region of Iraq as a Case Study (EIOGI). IEEE, 2017. http://dx.doi.org/10.1109/eiogi.2017.8267626.

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de Oliveira Nunes, Lilian, Airton A. Martin, Landulfo Silveira, Jr., Marcelo Zampieri, and Egberto Munin. "Biochemical changes between normal and BCC tissue: a FT-Raman study." In Biomedical Optics 2003, edited by Britton Chance, Robert R. Alfano, Bruce J. Tromberg, Mamoru Tamura, and Eva M. Sevick-Muraca. SPIE, 2003. http://dx.doi.org/10.1117/12.476884.

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Zemlyanukhina, O. A., E. N. Vasilchenko, N. N. Cherkasova, and N. A. Karpechenko. "Physiological and biochemical markers in the study of sugar beet plants." In CURRENT STATE, PROBLEMS AND PROSPECTS OF THE DEVELOPMENT OF AGRARIAN SCIENCE. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2019. http://dx.doi.org/10.33952/09.09.2019.108.

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"Case Study: Simulating the Biochemical Decomposition Process of Different Organic Wastes." In PROCEEDING BOOK OF 1ST INTERNATIONAL CONFERENCE ON MODERN AND ADVANCED RESEARCH ICMAR 2023. All Sciences Academy, 2023. http://dx.doi.org/10.59287/icmar.1253.

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Horiguchi, Atsushi, and Toshihiko Shiraishi. "Study on a Cell Mechanosensing System by Measuring Structural Deformation and Biochemical Response." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51456.

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Mechanical stimulation induces new bone formation in vivo and promotes the metabolic activity and the gene expression of osteoblasts in vitro. It was reported that biochemical signals of osteoblasts to sense mechanical stimulation are activated according to their actin cytoskeletal deformation. However, there have been not so many researches on the relationship between cytoskeletal deformation and biochemical response. Here we show an original method to investigate a cell mechanosensing system and the quantitative relationship between the deformation of cytoskeletal structure and the change of intracellular calcium ion concentration as biochemical response in a living cell stimulated by a micropipette. Gene transfection of green fluorescent protein to osteoblastic cells enabled visualization of actin in cells. When local deformation was applied to a single osteoblastic cell by a micropipette, the displacement distribution of cytoskeletal structure in the whole cell was automatically obtained from the two images of the cell before and after deformation by using Kanade-Lucas-Tomasi (KLT) method. Intracellular calcium ion response to mechanical stimulation was measured as the spatial and temporal changes of intensity of Fura Red loaded to a cell. As a result, we obtained the quantitative relationship between structural deformation and biochemical response of a cell and found that the change of calcium ion concentration increases with increasing the displacement of actin cytoskeleton. It indicates that the deformation of actin cytoskeleton is highly related to the cell mechanosensing system.
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Wu, Zujian, and Huiqin Du. "A study of parallel and evolutionary framework for modelling biochemical signalling pathways." In 2016 2nd IEEE International Conference on Computer and Communications (ICCC). IEEE, 2016. http://dx.doi.org/10.1109/compcomm.2016.7924810.

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Reports on the topic "Biochemical Study"

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Moran, Nava, Richard Crain, and Wolf-Dieter Reiter. Regulation by Light of Plant Potassium Uptake through K Channels: Biochemical, Physiological and Biophysical Study. United States Department of Agriculture, September 1995. http://dx.doi.org/10.32747/1995.7571356.bard.

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The swelling of plant motor cells is regulated by various signals with almost unknown mediators. One of the obligatory steps in the signaling cascade is the activation of K+-influx channels -K+ channels activated by hyperpolarization (KH channels). We thus explored the regulation of these channels in our model system, motor cell protoplasts from Samanea saman, using patch-clamp in the "whole cell" configuration. (a) The most novel finding was that the activity of KH channels in situ varied with the time of the day, in positive correlation with cell swelling: in Extensor cells KH channels were active in the earlier part of the day, while in Flexor cells only during the later part of the day; (b) High internal pH promoted the activity of these channels in Extensor cells, opposite to the behavior of the equivalent channels in guard cells, but in conformity with the predicted behavior of the putative KH channel, cloned from S. saman recently; (c) HIgh external K+ concentration increased (KH channel currents in Flexor cells. BL depolarized the Flexor cells, as detected in cell-attached patch-clamp recording, using KD channels (the K+-efflux channels) as "voltage-sensing devices". Subsequent Red-Light (RL) pulse followed by Darkness, hyperpolarized the cell. We attribute these changes to the inhibition of the H+-pump by BL and its reactivation by RL, as they were abolished by an H+-pump inhibitor. BL increased also the activity KD channels, in a voltage-independent manner - in all probability by an independent signaling pathway. Blue-Light (BL), which stimulates shrinking of Flexor cells, evoked the IP3 signaling cascade (detected directly by IP3 binding assay), known to mobilize cytosolic Ca2+. Nevertheless, cytosolic Ca2+ . did not activate the KD channel in excised, inside-out patches. In this study we established a close functional similarity of the KD channels between Flexor and Extensior cells. Thus the differences in their responses must stem from different links to signaling in both cell types.
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Jander, Georg, Gad Galili, and Yair Shachar-Hill. Genetic, Genomic and Biochemical Analysis of Arabidopsis Threonine Aldolase and Associated Molecular and Metabolic Networks. United States Department of Agriculture, January 2010. http://dx.doi.org/10.32747/2010.7696546.bard.

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Since the amino acids threonine and isoleucine can be limiting in mammalian diet and there is interest in increasing their abundance in certain crop plants. To meet this need, a BARD proposal was written with two main research objectives: (i) investigate new avenues for manipulating threonine and isoleucine content in plants and (ii) study the role of threonine aldolase in plant metabolism. Research conducted to meet these goals included analysis of the sub-cellular localization of threonine aldolase in the plant, analysis of metabolic flux in developing embryos, over- and under-expression of Arabidopsis threonine aldolases, and transcriptional and metabolic analysis of perturbations resulting from altered threonine aldolase expression. Additionally, the broader metabolic effects of increasing lysine biosynthesis were investigated. An interesting observation that came up in the course of the project is that threonine aldolase activity affects methionine gamma-lyase in Arabidopsis. Further research showed that threonine deaminase and methionine gamma-lyase both contribute to isoleucine biosynthesis in plants. Therefore, isoleucine content can be altered by manipulating the expression of either or both of these enzymes. Additionally, both enzymes contribute to the up to 100-fold increase in isoleucine that is observed in drought-stressed Arabidopsis. Toward the end of the project it was discovered that through different projects, both groups had been able to independently up-regulate phenylalanine accumulation by different mechanisms. The Galili lab transformed Arabidopsis with a feedbackinsensitive bacterial enzyme and the Jander lab found a feedback insensitive mutation in Arabidopsis arogenate dehydratase. Exchange of the respective plant lines has allowed a comparative analysis of the different methods for increasing phenylalanine content and the creation of double mutants. The research that was conducted as part of this BARD project has led to new insights into plant amino acid metabolism. Additionally, new approaches that were found to increase the accumulation of threonine, isoleucine, and phenylalanine in plants have potential practical applications. Increased threonine and isoleucine levels can increase the nutritional value of crop plants. Elevated isoleucine accumulation may increase the osmotic stress tolerance of plants. Up-regulation of phenylalanine biosynthesis can be used to increase the production of downstream higher-value plant metabolites of biofuel feed stocks.
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3

Applebaum, Shalom W., Lawrence I. Gilbert, and Daniel Segal. Biochemical and Molecular Analysis of Juvenile Hormone Synthesis and its Regulation in the Mediterranean Fruit Fly (Ceratitis capitata). United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7570564.bard.

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Original Objectives and revisions: (1) "To determine the biosynthetic pathway of JHB3 in the adult C. capitata CA in order to establish parameters for the future choice and synthesis of suitable inhibitors". Modified: to determine the pattern of FR-7 biosynthesis during normal reproductive maturation, and identify enzymes potentially involved in its synthesis. (2) "To correlate allatal epoxidase activity to the biosynthesis of JHB3 at different stages of reproductive maturation/vitellogenesis and evaluate the hypothesis that a specific JH-epoxidase may be rate limiting". Modified: to study the effects of epoxidase inhibitors on the pattern of allatal JH biosynthesis in vitro and on female reproduction in vive. (3) "To probe and clone the gene homologous to ap from C. capitata, determine its exon-intron organization, sequence it and demonstrate its spatial and temporal expression in larvae, pupae and adults." The "Medfly" (Ceratitis capitata) is a serious polyphagous fruit pest, widely distributed in subtropical regions. Damage is caused by oviposition and subsequent development of larvae. JH's are dominant gonadotropic factors in insects. In the higher Diptera, to which the Medfly belongs, JHB3 is a major homolog. It comprises 95% of the total JH produced in vitro in D. melanogaster, with JH-III found as a minor component. The biosynthesis of both JH-III and JHB3 is dependent on epoxidation of double bonds in the JH molecule. The specificity of such epoxidases is unknown. The male accessory gland D. melanogaster produces a Sex Peptide, transferred to the female during copulation. SP reduces female receptivity while activating specific JH biosynthesis in vitro and inducing oviposition in vive. It also reduces pheromone production and activates CA of the moth Helicoverpa armigera. In a previous study, mutants of the apterous (ap) gene of D. melanogaster were analyzed. This gene induces previteilogenic arrest which can be rescued by external application of JH. Considerable progress has been made in recombinant DNA technology of the Medfly. When fully operative, it might be possible to effectively transfer D. melanogaster endocrine gene-lesions into the Medfly as a strategy for their genetic control. A marked heterogeneity in the pattern of JH homologs produced by Medfly CA was observed. Contrary to the anticipated biosynthesis of JHB;, significant amounts of an unknown JH-like compound, of unknown structure and provisionally termed FR-7, were produced, in addition to significant amounts of JH-III and JHB3. Inhibitors of monooxygenases, devised for their effects on ecdysteroid biosynthesis, affect Medfly JH biosynthesis but do not reduce egg deposition. FR-7 was isolated from incubation media of Medfly CA and examined by various MS procedures, but its structure is not yet resolved. MS analysis is being done in collaboration with Professor R.R.W. Rickards of the Australian National University in Canberra, Australia. A homologue of the ap gene of D. melanogaster exists in the Medfly. LIM domains and the homeo-domain, important for the function of the D. melanogaster ap gene, are conserved here too. Attempts to clone the complete gene were unsuccessful. Due to the complexity of JH homologs, presence of related FR-7 in the biosynthetic products of Medfly CA and lack of reduction in eggs deposited in the presence of monooxygenase inhibitors, inhibition of epoxidases is not a feasible alternative to control Medfly reproduction, and raises questions which cannot be resolved within the current dogma of hormonal control of reproduction in Diptera. The Medfly ap gene has similar domains to the D. melanogaster ap gene. Although mutant ap genes are involved in JH deficiency, ap is a questionable candidate for an endocrine lesion, especially since the D. melanogoster gene functions is a transcription factor.
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4

Wurl, Oliver. Biofilm-like habitat at the sea-surface: A mesocosm study, Cruise No. POS537, 14.09.2019 – 04.10.2019, Malaga (Spain) – Cartagena (Spain) - BIOFILM. University of Oldenburg, November 2020. http://dx.doi.org/10.3289/cr_pos537.

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OceanRep OceanRep Startseite Kontakt Schnellsuche Einfache Suche Erweiterte Suche Blättern Autor Forschungsbereich Publikationsart Jahr Studiengang Neuzugänge Artikel – begutachtet Alle Über uns GEOMAR Bibliothek Open Access Policies Grundsätze Hilfe FAQs Statistik Impressum Biofilm-like habitat at the sea-surface: A mesocosm study, Cruise No. POS537, 14.09.2019 – 04.10.2019, Malaga (Spain) – Cartagena (Spain) - BIOFILM . Logged in as Heidi Düpow Einträge verwaltenManage recordsManage shelvesProfilGespeicherte SuchenBegutachtungAdminLogout - Tools Wurl, Oliver, Mustaffa, Nur Ili Hamizah, Robinson, Tiera-Brandy, Hoppe, Jennifer, Jaeger, Leonie, Striebel, Maren, Heinrichs, Anna-Lena, Hennings, Laura Margarethe, Goncalves, Rodrigo, Ruiz Gazulla, Carlota und Ferrera, Isabel (2020) Biofilm-like habitat at the sea-surface: A mesocosm study, Cruise No. POS537, 14.09.2019 – 04.10.2019, Malaga (Spain) – Cartagena (Spain) - BIOFILM . Open Access . POSEIDON Berichte . University of Oldenburg, Oldenburg, 35 pp. [img] Text Cruise_Reports_POS537_final.pdf - publizierte Version Available under License Creative Commons: Attribution 4.0. Download (2417Kb) | Vorschau Abstract Biofilm-like properties can form on sea surfaces, but an understanding of the underlying processes leading to the development of these biofilms is not available. We used approaches to study the development of biofilm-like properties at the sea surface, i.e. the number, abundance and diversity of bacterial communities and phytoplankton, the accumulation of gel-like particles and dissolved tracers. During the expedition POS537 we used newly developed and free drifting mesocosms and performed incubation experiments. With these approaches we aim to investigate the role of light and UV radiation as well as the microbes themselves, which lead to the formation of biofilms. With unique microbial interactions and photochemical reactions, sea surface biofilms could be biochemical reactors with significant implications for ocean and climate research, e.g. with respect to the marine carbon cycle, diversity of organisms and oceanatmosphere interactions.
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Fallik, Elazar, Robert Joly, Ilan Paran, and Matthew A. Jenks. Study of the Physiological, Molecular and Genetic Factors Associated with Postharvest Water Loss in Pepper Fruit. United States Department of Agriculture, December 2012. http://dx.doi.org/10.32747/2012.7593392.bard.

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The fruit of pepper (Capsicum annuum) commonly wilts (or shrivels) during postharvest storage due to rapid water loss, a condition that greatly reduces its shelf life and market value. The fact that pepper fruit are hollow, and thus have limited water content, only exacerbates this problem in pepper. The collaborators on this project completed research whose findings provided new insight into the genetic, physiological, and biochemical basis for water loss from the fruits of pepper (Capsicum annuum and related Capsicum species). Well-defined genetic populations of pepper were used in this study, the first being a series of backcross F₁ and segregating F₂, F₃, and F₄ populations derived from two original parents selected for having dramatic differences in fruit water loss rate (very high and very low water loss). The secondly population utilized in these studies was a collection of 50 accessions representing world diversity in both species and cultivar types. We found that an unexpectedly large amount of variation was present in both fruit wax and cutin composition in these collections. In addition, our studies revealed significant correlations between the chemical composition of both the fruit cuticular waxes and cutin monomers with fruit water loss rate. Among the most significant were that high alkane content in fruit waxes conferred low fruit water loss rates and low permeability in fruit cuticles. In contrast, high amounts of terpenoids (plus steroidal compounds) were associated with very high fruit water loss and cuticle permeability. These results are consistent with our models that the simple straight chain alkanes pack closely together in the cuticle membrane and obstruct water diffusion, whereas lipids with more complex 3-dimensional structure (such as terpenoids) do not pack so closely, and thus increase the diffusion pathways. The backcross segregating populations were used to map quantitative trait loci (QTLs) associated with water loss (using DART markers, Diversity Arrays Technology LTD). These studies resulted in identification of two linked QTLs on pepper’s chromosome 10. Although the exact genetic or physiological basis for these QTLs function in water loss is unknown, the genotypic contribution in studies of near-isogenic lines selected from these backcross populations reveals a strong association between certain wax compounds, the free fatty acids and iso-alkanes. There was also a lesser association between the water loss QTLs with both fruit firmness and total soluble sugars. Results of these analyses have revealed especially strong genetic linkages between fruit water loss, cuticle composition, and two QTLs on chromosome 10. These findings lead us to further speculate that genes located at or near these QTLs have a strong influence on cuticle lipids that impact water loss rate (and possibly, whether directly or indirectly, other traits like fruit firmness and sugar content). The QTL markers identified in these studies will be valuable in the breeding programs of scientists seeking to select for low water loss, long lasting fruits, of pepper, and likely the fruits of related commodities. Further work with these newly developed genetic resources should ultimately lead to the discovery of the genes controlling these fruit characteristics, allowing for the use of transgenic breeding approaches toward the improvement of fruit postharvest shelf life.
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Fridman, Eyal, and Eran Pichersky. Tomato Natural Insecticides: Elucidation of the Complex Pathway of Methylketone Biosynthesis. United States Department of Agriculture, December 2009. http://dx.doi.org/10.32747/2009.7696543.bard.

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Plant species synthesize a multitude of specialized compounds 10 help ward off pests. and these in turn may well serve as an alternative to synthetic pesticides to reduce environmental damage and health risks to humans. The general goal of this research was to perform a genetic and biochemical dissection of the natural-insecticides methylketone pathway that is specific to the glandular trichomes of the wild species of tomato, Solanumhabrochaites f. glabratum (accession PI126449). Previous study conducted by us have demonstrated that these compounds are synthesized de novo as a derivate pathway of the fatty acid biosynthesis, and that a key enzyme. designated MethylketoneSynthase 1 (MKS 1). catalyzes conversion of the intermediate B-ketoacyl- ACPs to the corresponding Cn-1 methylketones. The approach taken in this proposed project was to use an interspecific F2 population. derived from the cross between the cultivated lV182 and the wild species PIl26449. for three objectives: (i) Analyze the association between allelic status of candidate genes from the fatty acid biosynthesis pathway with the methylketone content in the leaves (ii) Perform bulk segregant analysis of genetic markers along the tomato genome for identifying genomic regions that harbor QTLs for 2TD content (iii) Apply differential gene expression analysis using the isolated glands of bulk segregant for identifying new genes that are involved in the pathway. The genetic mapping in the interspecific F2 population included app. 60 genetic markers, including the candidate genes from the FAS pathway and SSR markers spread evenly across the genome. This initial; screening identified 5 loci associated with MK content including the candidate genes MKS1, ACC and MaCoA:ACP trans. Interesting observation in this genetic analysis was the connection between shape and content of the glands, i.e. the globularity of the four cells, typical to the wild species. was associated with increased MK in the segregating population. In the next step of the research transcriptomic analysis of trichomes from high- and 10w-MK plants was conducted. This analysis identified a new gene, Methy1ketone synthase 2 (MKS2), whose protein product share sequence similarity to the thioesterase super family of hot-dog enzymes. Genetic analysis in the segregating population confirmed its association with MK content, as well as its overexpression in E. coli that led to formation of MK in the media. There are several conclusions drawn from this research project: (i) the genetic control of MK accumulation in the trichomes is composed of biochemical components in the FAS pathway and its vicinity (MKS 1 and MKS2). as well as genetic factors that mediate the morphology of these specialized cells. (ii) the biochemical pathway is now realized different from what was hypothesized before with MKS2 working upstream to I\1KS 1 and serves as the interface between primary (fatty acids) and secondary (MK) metabolism. We are currently testing the possible physical interactions between these two proteins in vitro after the genetic analysis showed clear epistatic interactions. (iii) the regulation of the pathway that lead to specialized metabolism in the wild species is largely mediated by transcription and one of the achievements of this project is that we were able to isolate and verify the specificity of the MKS1 promoter to the trichomes which allows manipulation of the pathways in these cells (currently in progress). The scientific implications of this research project is the advancement in our knowledge of hitherto unknown biochemical pathway in plants and new leads for studying a new family in plants (hot dog thioesterase). The agricultural and biotechnological implication are : (i) generation of new genetic markers that could assist in importing this pathway to cultivated tomato hence enhancing its natural resistance to insecticides, (ii) the discovery of MKS2 adds a new gene for genetic engineering of plants for making new fatty acid derived compounds. This could be assisted with the use of the isolated and verified MKS1 promoter. The results of this research were summarized to a manuscript that was published in Plant Physiology (cover paper). to a chapter in a proceeding book. and one patent was submitted in the US.
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7

Freeman, Stanley, and Russell J. Rodriguez. The Interaction Between Nonpathogenic Mutants of Colletotrichum and Fusarium, and the Plant Host Defense System. United States Department of Agriculture, September 2000. http://dx.doi.org/10.32747/2000.7573069.bard.

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The intent of this proposal was to study the interaction between nonpathogenic mutants of Colletotrichum magna and Fusarium oxysporum, and the cucurbit host defense system. We had shown previously that a nonpathogenic endophytic mutant path- 1 of C. magna, caused no visible disease symptoms but protected watermelon seedlings from disease caused by the wildtype isolate and F. o. niveum. Objectives were: 1) Determine the microscopic, biochemical and molecular genetic interaction between "protected" (path- 1 colonized) cucurbit hosts and wildtype isolates of C. magna; 2) Isolate non-pathogenic mutants of F.o. melonis and test feasibility for protecting plants against fungal diseases. We found that path-1 caused no visible disease symptoms in cucurbit seedlings but conferred disease resistance against pathogenic isolates of C. magna, C. orbiculare, and F. oxysporum. Disease resistance conferred by path-1 correlated to a decrease in the time of activation of host defense systems after exposure of path-1 colonized plants to virulent pathogens. This was determined by monitoring the biochemical activity of PAL and peroxidase, and the deposition of lignin. It appears that path-1-conferred disease resistance is a multigenic phenomenon which should be more difficult for pathogen to overcome than single gene conferred resistance. Based on the benefits conferred by path-1, we have defined this mutant as expressing a mutualistic lifestyle. REMI (restriction enzyme-mediated integration) nonpathogenic mutants were also isolated using pHA1.3 plasmid linearized with Hind III and transformed into wildtype C. magna. The integrated vector and flanking genomic DNA sequences in REMI mutant R1 was re-isolated and cloned resulting in a product of approximately 11 kb designated pGMR1. Transformations of wildtype C. magna with pGMR1 resulted in the same non-pathogenic phenotype. A nonpathogenic mutant of F.o. melonis (pathogenic to melon) was isolated that colonized melon plants but elicited no disease symptoms in seedlings and conferred 25 - 50% disease protection against the virulent wildtype isolate. Subsequently, nonpathogenic mutant isolates of F.o. niveum (pathogenic to watermelon) were also isolated. Their protection capacity against the respective wildtype parent is currently under investigation. This research has provided information toward a better understanding of host-parasite interactions; specifically, endophytes, pathogens and their hosts. It will also allow us to assess the potential for utilizing nonpathogenic mutants as biological control agents against fungal pathogens and isolating molecular genetic factors of pathogenicity in Fusarium.
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8

Chamovitz, Daniel A., and Zhenbiao Yang. Chemical Genetics of the COP9 Signalosome: Identification of Novel Regulators of Plant Development. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7699844.bard.

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This was an exploratory one-year study to identify chemical regulators of the COP9 signalosome. Chemical Genetics uses small molecules to modify or disrupt the function of specific genes/proteins. This is in contrast to classical genetics, in which mutations disrupt the function of genes. The underlying concept is that the functions of most proteins can be altered by the binding of a chemical, which can be found by screening large libraries for compounds that specifically affect a biological, molecular or biochemical process. In addition to screens for chemicals which inhibit specific biological processes, chemical genetics can also be employed to find inhibitors of specific protein-protein interactions. Small molecules altering protein-protein interactions are valuable tools in probing protein-protein interactions. In this project, we aimed to identify chemicals that disrupt the COP9 signalosome. The CSN is an evolutionarily conserved eight-subunit protein complex whose most studied role is regulation of E3 ubiquitinligase activity. Mutants in subunits of the CSN undergo photomorphogenesis in darkness and accumulate high levels of pigments in both dark- and light-grown seedlings, and are defective in a wide range of important developmental and environmental-response pathways. Our working hypothesis was that specific molecules will interact with the CSN7 protein such that binding to its various interacting proteins will be inhibited. Such a molecule would inhibit either CSN assembly, or binding of CSN-interacting proteins, and thus specifically inhibit CSN function. We used an advanced chemical genetic screen for small-molecule-inhibitors of CSN7 protein-protein interactions. In our pilot study, following the screening of ~1200 unique compounds, we isolated four chemicals which reproducibly interfere with CSN7 binding to either CSN8 or CSN6.
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9

Naim, Michael, Andrew Spielman, Shlomo Nir, and Ann Noble. Bitter Taste Transduction: Cellular Pathways, Inhibition and Implications for Human Acceptance of Agricultural Food Products. United States Department of Agriculture, February 2000. http://dx.doi.org/10.32747/2000.7695839.bard.

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Historically, the aversive response of humans and other mammals to bitter-taste substances has been useful for survival, since many toxic constituents taste bitter. Today, the range of foods available is more diverse. Many bitter foods are not only safe for consumption but contain bitter constituents that provide nutritional benefits. Despite this, these foods are often eliminated from our current diets because of their unacceptable bitterness. Extensive technology has been developed to remove or mask bitterness in foods, but a lack of understanding of the mechanisms of bitterness perception at the taste receptor level has prevented the development of inhibitors or efficient methods for reducing bitterness. In our original application we proposed to: (a) investigate the time course and effect of selected bitter tastants relevant to agricultural products on the formation of intracellular signal molecules (cAMP, IP3, Ca2+) in intact taste cells, in model cells and in membranes derived therefrom; (b) study the effect of specific bitter taste inhibitors on messenger formation and identify G-proteins that may be involved in tastant-induced bitter sensation; (c) investigate interactions and self-aggregation of bitter tastants within membranes; (d) study human sensory responses over time to these bitter-taste stimuli and inhibitors in order to validate the biochemical data. Quench-flow module (QFM) and fast pipetting system (FPS) allowed us to monitor fast release of the aforementioned signal molecules (cGMP, as a putative initial signal was substituted for Ca2+ ions) - using taste membranes and intact taste cells in a time range below 500 ms (real time of taste sensation) - in response to bitter-taste stimulation. Limonin (citrus) and catechin (wine) were found to reduce cellular cAMP and increase IP3 contents. Naringin (citrus) stimulated an IP3 increase whereas the cheese-derived bitter peptide cyclo(leu-Trp) reduced IP3 but significantly increased cAMP levels. Thus, specific transduction pathways were identified, the results support the notion of multiple transduction pathways for bitter taste and cross-talk between a few of those transduction pathways. Furthermore, amphipathic tastants permeate rapidly (within seconds) into liposomes and taste cells suggesting their availability for direct activation of signal transduction components by means of receptor-independent mechanisms within the time course of taste sensation. The activation of pigment movement and transduction pathways in frog melanophores by these tastants supports such mechanisms. Some bitter tastants, due to their amphipathic properties, permeated (or interacted with) into a bitter tastant inhibitor (specific phospholipid mixture) which apparently forms micelles. Thus, a mechanism via which this bitter taste inhibitor acts is proposed. Human sensory evaluation experiments humans performed according to their 6-n-propyl thiouracil (PROP) status (non-tasters, tasters, super-tasters), indicated differential perception of bitterness threshold and intensity of these bitter compounds by different individuals independent of PROP status. This suggests that natural products containing bitter compounds (e.g., naringin and limonin in citrus), are perceived very differently, and are in line with multiple transduction pathways suggested in the biochemical experiments. This project provides the first comprehensive effort to explore the molecular basis of bitter taste at the taste-cell level induced by economically important and agriculturally relevant food products. The findings, proposing a mechanism for bitter-taste inhibition by a bitter taste inhibitor (made up of food components) pave the way for the development of new, and perhaps more potent bitter-taste inhibitors which may eventually become economically relevant.
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10

Shoseyov, Oded, Steven A. Weinbaum, Raphael Goren, and Abhaya M. Dandekar. Biological Thinning of Fruit Set by RNAase in Deciduous Fruit Trees. United States Department of Agriculture, August 1993. http://dx.doi.org/10.32747/1993.7568110.bard.

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Fruit thinning is a common and necessary practice for commercial fruit production in many deciduous tree fruit species. Fruit thinning in apple may be accomplished with a variety of chemical thinning agents, but the use of these chemicals is a subject of environmental concern. It has been shown recently that RNase enzyme, secreted from the stigma and the style, inhibits pollen germination and pollen tube elongation. In this study we have been able to show that Aspergillus niger B-1 RNase can effectively inhibit peach and apple pollen germination, and tube elongation in-vitro, as well as thin fruit in peach and apple, and reduce the number of seeds in citrus. The objectives of the research were to detrmine the conditions for effective thinning of (USA and Israel), develop fermentation process for cost effective production of RNase from A. niger. (Israel), and clone apple S-RNase cDNA (USA). All the objectives of the research were addressed. We have determined the optimal fermentation conditions for cost effective production of the A. niger at a 20,000 liters scale. TheA. niger B1 RNase was isolated to homogeneity and its kinetic and biochemical properties including its N-terminal sequence were fully characterized. The field test results both in Israel and California have shown variability in effectiveness and more work is needed to define the RNase concentration necessary to completely inhibit pollen development. Plant transformation vectors expressing anti-sense apple S-RNase genes were constructed (USA) with an attempt to produce self compatible transgenic apple trees. Bovine S-Protein cDNA was cloned and successfully expressed in E. coli (Israel). Plant transformation vector expressing the S-Protein gene was constructed (USA) with an attempt to produce transgenic plants expressing S-protein in the style. Exogenous application of S-peptide to these plants will result in active RNase and consequently prevention of fertilization.
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