11 resultados para Peptide bonds
em Brock University, Canada
Resumo:
The study examines the buddy film genre and the representation of masculinity in relation to the homosocial and the homoerotic. As a genre, the buddy films focus on male relationships, thematically seeking to mediate the boundaries surrounding the homosocial continuum and the intimacy and eroticism implicit in male bonding. Theories of genre, gender and identity are used to analyze the construction of masculine identity within the films. By providing a qualitative analysis of films from the 1960s to contemporary times, the research establishes a relationship between social changes, attitudes toward men and depictions of men. The buddy films adapt to address changes in the representation of masculinity, embodied in the difference between the male couple in the films. The early films of the 1960s served as templates that deconstructed traditional representations of male identity through articulating the tension within homosocial relationships. However, in the later films this tension became a refle~ive convention, acting to undermine the eroticism onto a displaced Other. The buddy film genre highlights the tension inherent to the male masquerade. This tension is situated in the need to represent the protagonist's homosocial relationship, while disavowing the eroticism that surrounds homosocial bonding. The structure of the buddy film genre, which focuses on the exploration of masculinity and representing the bonds of homosocial intimacy, makes these films a significant site for investigating the cultural construction of masculine identities.
Resumo:
A FMRFamide-like neuropeptide with the sequence "DRNFLRF-NH2" was recently isolated from pericardial organs of crayfish (Mercier et aI., Peptides, 14, 137-143, 1993). This neuropeptide, referred to as "DF2'" has already been shown to elicit cardioexcitation and to enhance synaptic transmission at neuromuscular junctions. Possible effects ofDF2 on muscle were investigated using superficial extensor muscles of the abdomen of the crayfish, Procambarus clar/ai. These muscles are of the tonic type and generate slow contractions that affect posture. DF2, at concentrations of 10-8 M or higher, increased muscle tonus and induced spontaneous, rhythmic contractions. These effects were antagonized by 5 rnM Mn2+ but not by lO-7M tetrodotoxin (TTX). Thus, they represent direct actions on muscle cells (rather than effects on motor neurons) and are likely to involve calcium influx. In contrast, deep abdominal extensor muscles, responsible for rapid swimming movements, and superficial flexor muscles do not generate contractions in response to the peptide. 2 Spontaneous contractions were also induced in the superficial extensor muscles by decreasing the temperature to II-13°C. Such contractions were also TTX-insensitive and they were antagonized by adding calcium channel blockers (Mn2+, Cd2+ or Ni2+) or by removing calcium from the bathing solution. This suggests that the spontaneous contractions depend on an influx of calcium from the extracellular solution. N-type and L-type voltage dependent calcium channel blockers did not reduce the effect of the peptide or the spontaneous contractions suggesting that calcium influx is not through N- or L-type calcium channels.
Resumo:
In 2007, Barry Bonds hit his 75 6th home run, breaking Hank Aaron's all-time record for most home runs in a Major League career. While it would be expected that such an accomplishment would induce unending praise and adulationfor the new record-holder, Bonds did not receive the treatment typically reserved for a beloved baseball hero. The purpose of this thesis is to assess media representations of the 2007 home run chase in order to shed light upon the factors which led to the mixed representations which accompanied BOlTds ' assault on Aaron's record. Drawingfrom Roland Barthes ' concept of myth, this thesis proposes that Bonds was portrayed in predominantly negative ways because he was seen as failing to embody the values of baseball's mythology. Using a qualitative content analysis of three major American newspapers, this thesis examines portrayals of Bonds and how he was shown both to represent and oppose elements from baseball's mythology, such as youth, and a distant, agrarian past. Recognizing the ways in which baseball is associated with American life, the media representations of Bonds are also evaluated to discern whether he was portrayed as personifYing a distinctly American set of values. The results indicate that, in media coverage of the 2007 home run chase, Bonds was depicted as a player of many contradictions. Most commonly, Bonds' athletic ability and career achievements were contrasted with unflattering descriptions of his character, including discussions of his alleged use of performance-enhancing substances. However, some coverage portrayed Bonds as embodying baseball myth. The findings contribute to an appreciation of the importance of historical context in examining media representations. This understanding is enhanced by an analysis of a selection of articles on Mark McGwire 's record-breaking season in 1998, and careful consideration of, and comparison to, the context under which Bonds performed in 2007. Findings are also shown to support the contemporary existence of a strong American baseball mythology. That Bonds is both condemned for failing to uphold the mythology and praised for personifYing it suggests that the values seen as inherent to baseball continue to act as an American cultural benchmark.
Resumo:
Neuropeptides are the largest group of signalling chemicals that can convey the information from the brain to the cells of all tissues. DPKQDFMRFamide, a member of one of the largest families of neuropeptides, FMRFamide-like peptides, has modulatory effects on nerve-evoked contractions of Drosophila body wall muscles (Hewes et aI.,1998) which are at least in part mediated by the ability of the peptide to enhance neurotransmitter release from the presynaptic terminal (Hewes et aI., 1998, Dunn & Mercier., 2005). However, DPKQDFMRFamide is also able to act directly on Drosophila body wall muscles by inducing contractions which require the influx of extracellular Ca 2+ (Clark et aI., 2008). The present study was aimed at identifying which proteins, including the membrane-bound receptor and second messenger molecules, are involved in mechanisms mediating this myotropic effect of the peptide. DPKQDFMRFamide induced contractions were reduced by 70% and 90%, respectively, in larvae in which FMRFamide G-protein coupled receptor gene (CG2114) was silenced either ubiquitously or specifically in muscle tissue, when compared to the response of the control larvae in which the expression of the same gene was not manipulated. Using an enzyme immunoassay (EIA) method, it was determined that at concentrations of 1 ~M- 0.01 ~M, the peptide failed to increase cAMP and cGMP levels in Drosophila body wall muscles. In addition, the physiological effect of DPKQDFMRFamide at a threshold dose was not potentiated by 3-lsobutyl-1-methylxanthine, a phosphodiesterase inhibitor, nor was the response to 1 ~M peptide blocked or reduced by inhibitors of cAMP-dependent or cGMP-dependent protein kinases. The response to DPKQDFMRFamide was not affected in the mutants of the phosholipase C-~ (PLC~) gene (norpA larvae) or IP3 receptor mutants, which suggested that the PLC-IP3 pathway is not involved in mediat ing the peptide's effects. Alatransgenic flies lacking activity of calcium/calmodul in-dependent protein kinase (CamKII showed an increase in muscle tonus following the application of 1 JlM DPKQDFMRFamide similar to the control larvae. Heat shock treatment potentiated the response to DPKQDFMRFamide in both ala1 and control flies by approximately 150 and 100 % from a non heat-shocked larvae, respectively. Furthermore, a CaMKII inhibitor, KN-93, did not affect the ability of peptide to increase muscle tonus. Thus, al though DPKQDFMRFamide acts through a G-protein coupled FMRFamide receptor, it does not appear to act via cAMP, cGMP, IP3, PLC or CaMKl1. The mechanism through which the FMRFamide receptor acts remains to be determined.
Resumo:
For the past 20 years, researchers have applied the Kalman filter to the modeling and forecasting the term structure of interest rates. Despite its impressive performance in in-sample fitting yield curves, little research has focused on the out-of-sample forecast of yield curves using the Kalman filter. The goal of this thesis is to develop a unified dynamic model based on Diebold and Li (2006) and Nelson and Siegel’s (1987) three-factor model, and estimate this dynamic model using the Kalman filter. We compare both in-sample and out-of-sample performance of our dynamic methods with various other models in the literature. We find that our dynamic model dominates existing models in medium- and long-horizon yield curve predictions. However, the dynamic model should be used with caution when forecasting short maturity yields
Resumo:
Form letter: a printed, 2 1/2 page copy of Jarvis Conklin and Co. Mortgage, Loans and Municipal Bonds letter to S.D. Woodruff, signed by James Conklin, n.d.
Printed blank to S.D. Woodruff from Jarvis, Conklin and Co. regarding enclosure of coupons for bonds
Resumo:
Printed blank to S.D. Woodruff from Jarvis, Conklin and Co. regarding enclosure of coupons for bonds, Jan. 24, 1885.
Resumo:
Printed blank of Statement of Security Form naming the bond as Jones County Texas Bonds for the purpose of building a courthouse. It is made out to S.D. Woodruff and dated June 12, 1885. An envelope addressed to Mr. S.D. Woodruff is also included. The postmarks are Kansas, 1885 and St. Catharines, June 13, 1885.
Resumo:
Notice regarding bonds and shareholders and the rights of the directors of the Long Point Company, n.d.
Resumo:
Flyer (2 double sided pages, printed) about the Dominion Power and Transmission Company bonds from R.W. Harris and Co. Bankers, New York, n.d.
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Flyer (2 double sided pages, printed) about railroad bonds from E.D. Shepard and Co. Bankers, New York, n.d.