Aerobic exercise in adolescence : self-efficacy and stage of change

The purpose of this cross-sectional exploratory study was to examine the relationships among self-efficacy, stage of change, and exercise behaviour in a sample of younger (Grade 9) and older (Grade 12) adolescents. A secondary objective of this study was to apply the transtheoretical model of Stage of Change, as a measure of intention to change, in order to discover the applicability of the model to an adolescent cohort in relation to exercise behaviour. This five-stage model is a self-report measure of an individual's readiness to adopt a new behaviour (e.g., regular exercise). The transtheoretical model incorporates Bandura's self-efficacy factor, which is purported to be a predictive measure of exercise behaviour and a covariant of stage. Exercise behaviour was measured with the Physical Activity Scale, and the University of Rhode Island Change Assessment Scale (URleA) was used to measure the stage of change and self-efficacy variables. The results of this study indicated significant differences between younger and older adolescents, and between males and females in their exercise behaviour. No significant differences were found for grade and gender on stage of change as measured by either a single-item question or a continuous measure of stage. Although grade and gender subgroups were not significantly different in their self-efficacy, significant interaction was found in the grade*gender variable.

An investigation of the nature and role of historicality in the thought of Dilthey and Heidegger

Introduction The question of the meaning, methods and philosophical manifestations of history is currently rife with contention. The problem that I will address in an exposition of the thought of Wilhelm Dilthey and Martin Heidegger, centers around the intersubjectivity of an historical world. Specifically, there are two interconnected issues. First, since all knowledge occurs to a person from within his or her historical age how can any person in any age make truth claims? In order to answer this concern we must understand the essence and role of history. Yet how can we come to an individual understanding ofwhat history is when the meanings that we use are themselves historically enveloped? But can we, we who are well aware of the knowledge that archaeology has dredged up from old texts or even from 'living' monuments of past ages, really neglect to notice these artifacts that exist within and enrich our world? Charges of wilful blindness would arise if any attempt were made to suggest that certain things of our world did not come down to us from the past. Thus it appears more important 2 to determine what this 'past' is and therefore how history operates than to simply derail the possibility for historical understanding. Wilhelm Dilthey, the great German historicist from the 19th century, did not question the existence of historical artifacts as from the past, but in treating knowledge as one such artifact placed the onus on knowledge to show itself as true, or meaningful, in light ofthe fact that other historical periods relied on different facts and generated different truths or meanings. The problem for him was not just determining what the role of history is, but moreover to discover how knowledge could make any claim as true knowledge. As he stated, there is a problem of "historical anarchy"!' Martin Heidegger picked up these two strands of Dilthey's thought and wanted to answer the problem of truth and meaning in order to solve the problem of historicism. This problem underscored, perhaps for the first time, that societal presuppositions about the past and present oftheir era are not immutable. Penetrating to the core of the raison d'etre of the age was an historical reflection about the past which was now conceived as separated both temporally and attitudinally from the present. But further than this, Heidegger's focus on asking the question of the meaning of Being meant that history must be ontologically explicated not merely ontically treated. Heidegger hopes to remove barriers to a genuine ontology by II 1 3 including history into an assessment ofprevious philosophical systems. He does this in order that the question of Being be more fully explicated, which necessarily for him includes the question of the Being of history. One approach to the question ofwhat history is, given the information that we get from historical knowledge, is whether such knowledge can be formalized into a science. Additionally, we can approach the question of what the essence and role of history is by revealing its underlying characteristics, that is, by focussing on historicality. Thus we will begin with an expository look at Dilthey's conception of history and historicality. We will then explore these issues first in Heidegger's Being and Time, then in the third chapter his middle and later works. Finally, we shall examine how Heidegger's conception may reflect a development in the conception of historicality over Dilthey's historicism, and what such a conception means for a contemporary historical understanding. The problem of existing in a common world which is perceived only individually has been philosophically addressed in many forms. Escaping a pure subjectivist interpretation of 'reality' has occupied Western thinkers not only in order to discover metaphysical truths, but also to provide a foundation for politics and ethics. Many thinkers accept a solipsistic view as inevitable and reject attempts at justifying truth in an intersubjective world. The problem ofhistoricality raises similar problems. We 4 -. - - - - exist in a common historical age, presumably, yet are only aware ofthe historicity of the age through our own individual thoughts. Thus the question arises, do we actually exist within a common history or do we merely individually interpret this as communal? What is the reality of history, individual or communal? Dilthey answers this question by asserting a 'reality' to the historical age thus overcoming solipsism by encasing individual human experience within the historical horizon of the age. This however does nothing to address the epistemological concern over the discoverablity of truth. Heidegger, on the other hand, rejects a metaphysical construel of history and seeks to ground history first within the ontology ofDasein, and second, within the so called "sending" of Being. Thus there can be no solipsism for Heidegger because Dasein's Being is necessarily "cohistorical", Being-with-Others, and furthermore, this historical-Being-in-the-worldwith- Others is the horizon of Being over which truth can appear. Heidegger's solution to the problem of solipsism appears to satisfy that the world is not just a subjective idealist creation and also that one need not appeal to any universal measures of truth or presumed eternal verities. Thus in elucidating Heidegger's notion of history I will also confront the issues ofDasein's Being-alongside-things as well as the Being of Dasein as Being-in-the-world so that Dasein's historicality is explicated vis-a-vis the "sending of Being" (die Schicken des S eins).

Locating and sequencing of the E3 and neighbouring regions in bovine advenovirus type 2

Adenoviruses are nonenveloped icosahedral shaped particles. The double stranded DNA viral genome is divided into 5 major early transcription units, designated E1 A, E1 B, and E2 to E4, which are expressed in a regulated manner soon after infection. The gene products of the early region 3 (E3), shown to be nonessential for viral replication in vitro, are believed to be involved in counteracting host immunosurveillance. In order to sequence the E3 region of Bovine adenovirus type 2 (BAV2) it was necessary to determine the restriction map for the plasmid pEA48. A physical restriction endonuclease map for BamHl, Clal, Eco RI, Hindlll, Kpnl, Pstt, Sail, and Xbal was constructed. The DNA insert in pEA48 was determined to be viral in origin using Southern hybridization. A human adenovirus type 5 recombinant plasmid, containing partial DNA fragments of the two transcription units L4 and L5 that lie just outside the E3, was used to localize this region. The recombinant plasmid pEA was subcloned to facilitate sequencing. The DNA sequences between 74.8 and 90.5 map units containing the E3, the hexon associated protein (pVIII), and the fibre gene were determined. Homology comparison revealed that the genes for the hexon associated pV11I and the fibre protein are conserved. The last 70 amino acids of the BAV2 pV11I were the most conserved, showing a similarity of 87 percent with Ad2 pV1I1. A comparison between the predicted amino acid sequences of BAV2 and Ad40, Ad41 , Ad2 and AdS, revealed that they have an identical secondary structure consisting of a tail, a shaft and a knob. The shaft is composed of 22, 15 amino acid motifs, with periodic glycines and hydrophobic residues. The E3 region was found to consist of about 2.3 Kbp and to encode four proteins that were greater than 60 amino acids. However, these four open reading frames did not show significant homology to any other known adenovirus DNA or protein sequence.

Solute effects on the production and decay of primary species in the flash photolysis of indole

Maximum production rates ofs and decay kinetics for the hydrated electron, the indolyl neutral radical and the indole triplet state have been obtained in the microsecond, broadband (X > 260 nm) flash photolysis of helium-saturated, neutral aqueous solutions of indole, in the absence and in the presence of the solutes NaBr, BaCl2*2H20 and CdSCV Fluorescence spectra and fluorescence lifetimes have also been obtained in the absence and in the presence of the above solutes, The hydrated electron is produced monophotonically and biphotonically at an apparent maximum rate which is increased by BaCl2*2H20 and decreased by NaBr and CdSOif. The neutral indolyl radical may be produced monophotonically and biphotonically or strictly monophotonically at an apparent maximum rate which is increased by NaBr and CdSO^ and is unaffected by BaCl2*2H20. The indole triplet state is produced monophotonically at a maximum rate which is increased by all solutes. The hydrated electron decays by pseudo first order processes, the neutral indolyl radical decays by second order recombination and the indole triplet state decays by combined first and second order processes. Hydrated electrons are shown to react with H , H2O, indole, Na and Cd"*""1"". No evidence has been found for the reaction of hydrated electrons with Ba . The specific rate of second order neutral indolyl radical recombination is unaffected by NaBr and BaCl2*2H20, and is increased by CdSO^. Specific rates for both first and second order triplet state decay processes are increased by all solutes. While NaBr greatly reduced the fluorescence lifetime and emission band intensity, BaCl2*2H20 and CdSO^ had no effect on these parameters. It is suggested that in solute-free solutions and in those containing BaCl2*2H20 and CdSO^, direct excitation occurs to CTTS states as well as to first excited singlet states. It is further suggested that in solutions containing NaBr, direct excitation to first excited singlet states predominates. This difference serves to explain increased indole triplet state production (by ISC from CTTS states) and unchanged fluorescence lifetimes and emission band intensities in the presence of BaCl2*2H20 and CdSOt^., and increased indole triplet state production (by ISC from S^ states) and decreased fluorescence lifetime and emission band intensity in the presence of NaBr. Evidence is presented for (a) very rapid (tx ^ 1 us) processes involving reactions of the hydrated electron with Na and Cd which compete with the reformation of indole by hydrated electron-indole radical cation recombination, and (b) first and second order indole triplet decay processes involving the conversion of first excited triplet states to vibrationally excited ground singlet states.