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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

EVENT-METHOD DIRECTED FORGETTING: THE INTENTIONAL FORGETTING OF EVENTS AND ACTIONS

Fawcett, Jonathan 18 June 2012 (has links)
In an event-method directed forgetting task, instructions to remember (R) or forget (F) were integrated throughout the presentation of four videos depicting common events (e.g., baking cookies). In a concurrent-instruction paradigm (Experiments 1-5) participants were instructed to remember (R) anything presented when the video border was green and to forget (F) anything presented when the video border was purple. In a post-instruction paradigm (Experiments 6-10) participants were instructed to remember anything preceding a green circle and to forget anything preceding a purple circle. The R or F segments lasted 35 s and were randomly assigned such that each video always contained 4 R and 4 F segments. Participants responded more accurately to cued-recall questions (Experiments 1 and 6) and true-false statements (Experiments 2-5 and 7-10) regarding R segments than F segments although this difference was found only for relatively specific (the woman added 3 cups of flour) as opposed to general (the woman added flour) information (Experiments 5 and 7-10). Participants retain a general representation of the events they intend to forget – even though this representation is not as specific as the representation of events they intend to remember. At encoding, participants were faster to discriminate targets overlaid upon F segments compared to R segments in the concurrent-instruction paradigm (Experiment 3) but were slower to detect targets presented following F compared to R instructions in the post-instruction paradigm (Experiments 6-7 and 9-10). Therefore, whereas both concurrent- and post-instruction paradigms produced comparable effects on subsequent mnemonic performance, the underlying processes are not identical. In the concurrent-instruction paradigm, participants needed to control access to working memory; in the post-instruction paradigm, participants needed to control the contents of working memory. In the former case, we expect that participants minimized processing of F segments while actively rehearsing R segments. In the latter case, we expect that participants engaged one or more active mechanisms associated with the removal of processing resources from the representation of the F segments (functionally terminating rehearsal) while focusing instead on the elaborative rehearsal of the R segments.
22

The development of sulfamates as latent directed metalation groups. Total synthesis of schumanniophytine. Divergent synthesis of substituted chromone 3- and 8-carboxamides.

Macklin, Todd Kristopher 04 December 2007 (has links)
N,N-Diethyl-O-sulfamate (OSO2NEt2) has been established as a new directed metalation group (DMG). Its similarity to the established O-carbamate DMG has prompted investigation into its potential as a partner in transition metal-catalyzed cross coupling reactions with aryl organometallics with the intention to develop a new route to contiguously substituted aromatics. Furthermore, aryne formation of ortho-magnesiated O-sulfamates at higher temperatures can be trapped with furan to afford cycloaddition products having substitution patterns difficult to prepare by similar methods. Schumanniophytine is a structurally interesting alkaloid possessing anti-viral activity. Thus far, only a single synthesis has been reported which proceeds in poor yield and offers little opportunity for the synthesis of structurally diverse schumanniophytine derivatives. Herein we report the total synthesis of schumanniophytine by a directed ortho metalation (DoM) – cross coupling strategy using a key directed remote metalation (DreM) step. The synthesis proceeds in 10 steps with 24% overall yield, offering plenty of opportunity for structural variation. Naturally abundant chromone derivatives contain an array of biological activities. The ability to prepare differentially substituted chromones in a rapid manner is of great interest in medicinal chemistry. Reported is a general and divergent synthesis of chromone carboxamides, from easily prepared 2-but-2-ynoyl aryl O-carbamates. The reaction proceeds by carbamoyl translocation and anionic Fries rearrangement followed by Michael addition of the initially generated cumulenolate for which evidence is provided. Further metalation and borylation reactions of the synthesized compounds allow the regioselective construction of polysubstituted chromones. / Thesis (Ph.D, Chemistry) -- Queen's University, 2007-11-30 11:18:51.673
23

Development of an enzyme linked immunosorbant assay for quantitative detection of murine anti-human antibodies /

Barboni, Paul, January 2004 (has links)
Thesis (M.A.)--Central Connecticut State University, 2004. / Thesis advisor: Kathy Martin. " ... in partial fulfillment of the requirements for the degree of Master of Arts in Biological Sciences." Includes bibliographical references (leaf 36). Also available via the World Wide Web.
24

Graded traces and irreducible representations of Aut(A(Gamma)) acting on graded A(Gamma) and A(Gamma)!

Duffy, Colleen M. January 2008 (has links)
Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Mathematics." Includes bibliographical references (p. 82-83).
25

Solid state capacitor discharge pulsed power supply for railguns

Black, Jesse H. January 2007 (has links) (PDF)
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 2007. / Thesis Advisor(s): Alexander L. Julian, William B. Maier. "March 2007." Includes bibliographical references (p. 53). Also available in print.
26

The use of directed evolution towards altering the substrate specificity of acyl-coenzyme A : isopenicillin N acyl transferase and transforming it from generalist to specialist

Doherty, Claire January 2011 (has links)
Acyl Coenzyme A: Isopenicillin N Acyl Transferase (AT) is a key enzyme in the biosynthesis of β-lactam antibiotics in penicillin producing organisms such as P. chrysogenum and A. nidulans. Its natural activity is to exchange the side chain of the low activity antibiotic IPN [18] for the phenylacetyl side chain resulting in the more active antibiotic Penicillin G [5]. The biosynthesis of β-lactams has been exploited towards producing these compounds for therapeutic use. However, increasing bacterial resistance means new analogues in this compound class are constantly sought.As well as improving current production methods of β-lactam antibiotics, AT's broad substrate specificity means it could potentially play a role in the development and production of alternative β-lactam antibiotics that are able to overcome resistance.This thesis describes the identification of an AT mutant with improved acylation activity (AAT activity) via screening of an AT library using a previously developed screening method. Approaches towards the development of a method for the identification of AT mutants with improved hydrolysis activity were also explored. The main problem to overcome in developing such a screen is the inhibitory effect of 6-APA [1], the product of hydrolysis, on AT's IAT activity. The first approach investigated the potential of increasing the sensitivity of an assay by targeting AT to the periplasm. A second approach using β-lactamases to hydrolyse 6-APA [1] thus freeing up the active site of AT was also investigated.
27

Increasing Milk Replacer Crude Protein Concentrations with or without Direct-Fed Microbial Supplementation on Pre-Weaned Holstein Calves during Heat Stress

Geiger, Adam J 11 May 2013 (has links)
This study was conducted to determine the effect of modified crude protein (CP) concentrations and a supplemental directed microbial in the milk replacer fed to Holstein calves during elevated ambient temperatures. Fortyour Holstein calves were randomly assigned treatments in a 2x2 factorial arrangement of treatments. Weekly and daily measurements were taken and analyzed using PROC MIXED in SAS. Calves fed increased CP concentrations in the milk replacer had greater body weight and frame measurements during the pre-weaning phase and at weaning. Directed microbial supplementation led to increased ADG during the post-weaning phase. Directed microbial supplementation and milk replacer modification helped alleviate heat stress through decreased rectal temperatures and rectal scores. Directed microbial supplementation increased fecal scores. Calves fed the control diet had greater volatile fatty acid concentrations in the rumen fluid, showing signs of increased rumen papillae development.
28

Site-Directed Mutagenesis of the -127 Activator Binding Site of the qa-2 Gene of Neurospora crassa

Arnett, Diana January 2000 (has links)
No description available.
29

Packing Directed Joins

Williams, Aaron January 2004 (has links)
Edmonds and Giles conjectured that the maximum number of directed joins in a packing is equal to the minimum weight of a directed cut, for any weighted directed graph. This is a generalization of Woodall's Conjecture (which is still open). Schrijver found the first known counterexample to the Edmonds-Giles Conjecture, while Cornuejols and Guenin found the next two. In this thesis we introduce new counterexamples, and prove that all minimal counterexamples of a certain type have now been found.
30

Packing Directed Joins

Williams, Aaron January 2004 (has links)
Edmonds and Giles conjectured that the maximum number of directed joins in a packing is equal to the minimum weight of a directed cut, for any weighted directed graph. This is a generalization of Woodall's Conjecture (which is still open). Schrijver found the first known counterexample to the Edmonds-Giles Conjecture, while Cornuejols and Guenin found the next two. In this thesis we introduce new counterexamples, and prove that all minimal counterexamples of a certain type have now been found.

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