Autonomic and electrocortical indices of performance monitoring and source memory discrimination in older and younger adults

Reduced capacity for executive cognitive function and for the autonomic control of cardiac responsivity are both concomitants of the aging process. These may be linked through their mutual dependence on medial prefrontal function, but the specifics ofthat linkage have not been well explored. Executive functions associated with medial prefrontal cortex involve various aspects ofperformance monitoring, whereas centrally mediated autonomic functions can be observed as heart rate variability (HRV), i.e., variability in the length of intervals between heart beats. The focus for this thesis was to examine the degree to which the capacity for phasic autonomic adjustments to heart rate relates to performance monitoring in younger and older adults, using measures of electrocortical and autonomic activity. Behavioural performance and attention allocation during two age-sensitive tasks could be predicted by various aspects of autonomic control. For young adults, greater influence of the parasympathetic system on HRV was beneficial for learning unfamiliar maze paths; for older adults, greater sympathetic influence was detrimental to these functions. Further, these relationships were primarily evoked when the task required the construction and use of internalized representations of mazes rather than passive responses to feedback. When memory for source was required, older adults made three times as many source errors as young adults. However, greater parasympathetic influence on HRV in the older group was conducive to avoiding source errors and to reduced electrocortical responses to irrelevant information. Higher sympathetic predominance, in contrast, was associated with higher rates of source error and greater electrocortical responses tq non-target information in both groups. These relations were not seen for 11 errors associated with a speeded perceptual task, irrespective of its difficulty level. Overall, autonomic modulation of cardiac activity was associated with higher levels of performance monitoring, but differentially across tasks and age groups. With respect to age, those older adults who had maintained higher levels of autonomic cardiac regulation appeared to have also maintained higher levels of executive control over task performance.

The nature of the highly artistic student in visual arts at secondary school /

This qualitative investigation examined the nature of 7 highly artistic visual arts students at 2 secondary schools in southcentral Ontario. Through interviews, questionnaires, observations, and artwork documents, this study attempted to understand these highly artistic students in terms of creativity, motivation, social and emotional perspectives, and cognitive processes. Data collection occuned over a 3-monlh period. and the data analysis program NVivo 7 was used for coding to develop themes and categories for organizing data. The findings of this study illustrate the significant place that \ isual arts can lake in the growth and development for the youth of today. Participants idcniificd dcxclopnig critical thinking and problem-solving skills, taking risks, and meeting challenges ilirouuh their engagement in the creative process. The transferability of these skills \\ as referenced to numerous aspects of their lives. By enhancing individual perspectives through the study of visual arts, their local and world connections were extended, and environmental and societal concerns evolved. In addition, the communicative opportunities that visual arts provided for these students in terms of personal expression provided emotional health and paths of personal discovery. Through the participants' production of artwork with the many stages this involves, combined with insight into their needs, the participants relayed miportant suggestions for programming enhancements and educational settmgs lor \ isiial arts classrooms. These suggestions are meaningful for educators and curriculum developers of the future.

A biochemical predictor of performance during mesophilic anaerobic fermentation of starch wastewater

The aim of this study was to determine the potential of biochemical parameters, such as enzyme activity and adenosine triphosphate (ATP) levels, as monitors of process performance in the Upflow Anaerobic Sludge Blanket (UASB) reactor utilizing a starch wastewater. The acid and alkaline phosphatase activity and the ATP content of the UASB sludge were measured in response to changes in flow rate and nutrient loading. Conventional parameters of process performance, such as gas production, acetic acid production, COD, phosphorus, nitrogen and suspended solids loadings and % COD removal were also monitored. The response of both biochemical and conventional parameters to changing process conditions was then compared. Alkaline phosphatase activity exhibited the highest activity over the entire study perioda A high suspended solids loading was observed to upset the system in terms of gas production, acetic acid production and % COD removala The initial rate of increase in alkaline phosphatase activity following an increase in loading was four times as great during process upset than under conditions of good performance. The change in enzyme actiVity was also more sensitive to process upset than changes in acetic acid production. The change in ATP content of the sludge with time suggested that enzyme actiVity was changing independently of the actual viable biomass present. The bacterial composition of the anaerobic sludge granules was similar to that of other sludge bed systems, at the light and scanning electron microscope level. Isolated serum bottle cultures produced several acids involved in anaerobic carbohydrate metabolism. The overall performance of the UASB system indicated that higher loadings of soluble nutrients could have been tolerated by the system.

The nature of avidyÄ in Buddhism and VedÄ nta

This thesis deals with the nature of ignorance as it was interpreted in the Upani~adic tradition, specifically in Advaita Vedanta, and in early and Mahayana Buddhism , e specially in the Madhyamika school of Buddhism. The approach i s a historical and comparative one. It examines the early thoughts of both the upanis.a ds and Buddhism abou t avidya (ignorance), shows how the notion was treated by the more speculative and philosphically oriented schools which base d themselves on the e arly works, and sees how their views differ. The thesis will show that the Vedinta tended to treat avidya as a topic for metaphysical s peculation as t he s chool developed, drifting from its initial e xistential concerns, while the Madhyamika remained in contact with the e xistential concerns evident in the first discourses of the Buddha. The word "notion" has been chosen for use in referring t o avidya, even though it may have non-intellectual and emotional connotations, to avoid more popular a lternatives such as "concept" or "idea". In neither the Upani,ads, Advaita Vedanta, or Buddhism is ignorance merely a concept or an idea. Only in a secondary sense, in texts and speech , does it become one. Avidya has more to do with the lived situation in which man finds himself, with the subjectobject separation in which he f eels he exists, than with i i i intel lect ual constr ucts . Western thought has begun to r ealize the same with concerns such as being in modern ontology, and has chosen to speak about i t i n terms of the question of being . Avidya, however, i s not a 'question' . If q ue stions we r e to be put regarding the nature of a vidya , they would be more of t he sort "What is not avidya?", though e ven here l anguage bestows a status t o i t which avidya does not have. In considering a work of the Eastern tradition, we f ace t he danger of imposing Western concepts on it. Granted t hat avidya is customari ly r endered i n English as ignorance, the ways i n which the East and West view i gno rance di f f er. Pedagogically , the European cultures, grounded in the ancient Greek culture, view ignorance as a l ack or an emptiness. A child is i gnorant o f certain t hings and the purpose o f f ormal education , in f act if not in theory, is to fill him with enough knowledge so that he can cope wit h t he complexities and the e xpectations of s ociety. On another level, we feel t hat study and research will l ead t o the discovery o f solutions, which we now lack , for problems now defying solut i on . The East, on the o t her hand, sees avidya in a d i fferent light.Ignorance isn't a lack, but a presence. Religious and philosophical l iterature directs its efforts not towards acquiring something new, but at removing t.he ideas and opinions that individuals have formed about themselves and the world. When that is fully accomplished, say the sages , t hen Wisdom, which has been obscured by those opinions, will present itself. Nothing new has to be learned, t hough we do have t o 'learn' that much. The growing interest in t he West with Eastern religions and philosophies may, in time, influence our theoretical and practical approaches to education and learning, not only in the established educati onal institutions, but in religious , p sychological, and spiritual activities as well. However, the requirements o f this thesis do no t permit a formulation of revolutionary method or a call to action. It focuses instead on the textual arguments which attempt to convince readers that t he world in which they take themselves to exist is not, in essence, real, on the ways i n which the l imitations of language are disclosed, and on the provisional and limited schemes that are built up to help students see through their ignorance. The metaphysic s are provisional because they act only as spurs and guides. Both the Upanisadic and Buddhist traditions that will be dealt with here stress that language constantly fails to encompass the Real. So even terms s uch as 'the Real', 'Absolute', etc., serve only to lead to a transcendent experience . The sections dealing with the Upanisads and Advaita Vedanta show some of the historical evolution of the notion of avidya, how it was dealt with as maya , and the q uestions that arose as t o its locus. With Gau?apada we see the beginnings of a more abstract treatment of the topic, and , the influence of Buddhism. Though Sankhara' S interest was primarily directed towards constructing a philosophy to help others attain mok~a ( l iberation), he too introduced t echnica l t e rminology not found in the works of his predecessors. His work is impressive , but areas of it are incomplete. Numbers of his followers tried to complete the systematic presentation of his insi ghts . Their work focuses on expl anat i ons of adhyasa (superimposition ) , t he locus and object of ignorance , and the means by which Brahman takes itself to be the jiva and the world. The section on early Buddhism examines avidya in the context o f the four truths, together with dubkha (suffering), the r ole it p l ays in t he chain of dependent c ausation , a nd t he p r oblems that arise with t he doctrine of anatman. With t he doct rines of e arly Buddhism as a base, the Madhyamika elaborated questions that the Buddha had said t e nded not t o edi f ication. One of these had to do with own - being or svabhava. Thi s serves a s a centr e around which a discussion o f i gnorance unfolds, both i ndividual and coll ective ignorance. There follows a treatment of the cessation of ignorance as it is discussed within this school . The final secti on tries to present t he similarities and differences i n the natures o f ignorance i n t he two traditions and discusses the factors responsible for t hem . ACKNOWLEDGEMENTS I would like to thank Dr. Sinha for the time spent II and suggestions made on the section dealing with Sankara and the Advait.a Vedanta oommentators, and Dr. Sprung, who supervised, direoted, corrected and encouraged the thesis as a whole, but especially the section on Madhyamika, and the final comparison.

Examining the Nature of Published Research About Mentoring in Higher Education

The various forms of mentoring relationships in higher education have all proven to be valuable, offering numerous benefits to mentors and protégés. Research into mentoring provides critical insight into aspects of these relationships, which can be used to advance theoretical and practical understandings of the topic. However, little is known about the methodological characteristics of the mentoring research itself. Using descriptive quantitative content analysis, I examined five years of articles published in five scholarly journals to determine the prevalence of research about mentoring in higher education. Not surprisingly, the prevalence of these articles differed significantly among journals in higher education (1.07% to 3.13%) compared to the considerably higher prevalence rate of 53.15% for the mentoring journal, Mentoring & Tutoring [χ2 (4, N = 82) = 143.98, p < .01]. I also report findings related to the prevalence of different empirical research traditions, research designs, and data sources, as well as various populations, such as faculty members or graduate students who serve as mentors or protégés. Given the limited number of mentoring articles published in higher education journals, I was unable to compare methodological characteristics across journals. Implications for theory, research, and practice in the area of mentoring in higher education are also suggested. Understanding the methodological characteristics of the current literature allows researchers to tailor their current studies by either continuing with existing trends in methodological approaches or seeking opportunities to incorporate under-utilized research traditions, designs, or data sources, with the aim of continuing to improve mentoring knowledge and outcomes.

The nature of compounds: A psychocentric perspective

Although compound words often seem to be words that themselves contain words, this paper argues that this is not the case for the vast majority of lexicalized compounds. Rather, it is claimed that as a result of acts of lexical processing, the constituents of compound words develop into new lexical representations. These representations are bound to specific morphological roles and positions (e.g., head, modifier) within a compound word. The development of these positionally bound compound constituents creates a rich network of lexical knowledge that facilitates compound processing and also creates some of the well-documented patterns in the psycholinguistic and neurolinguistic study of compounding.

Nature of crossmodal plasticity in the blind brain and interplay with sight restoration

Thèse réalisée en cotutelle avec l'Université catholique de Louvain.

Impact of the ego-dystonic nature of obsessions on treatment outcome in eating disorders

Il s'agit d'une hypothèse largement répandue que l’égo-dystonie et l’égo-syntonie caractérisent les obsessions dans les troubles des conduites alimentaires (TCA) et que ces facteurs sont cliniquement pertinents pour la conceptualisation et le traitement des TCA. Cependant, les résultats empiriques sur ce sujet sont rares. Compte tenu du chevauchement reconnu entre les TCA, notamment l'anorexie et la boulimie (BN), et le trouble obsessionnel-compulsif (TOC) dans la phénoménologie et les caractéristiques psychologiques, un programme de thérapie cognitive basée sur les inférences (TBI) de 24 semaines, démontré efficace dans le traitement des TOC, a été adapté pour traiter les TCA. La recherche sur le TOC suggère que la transformation des pensées intrusives en obsessions est liée à la mesure dans laquelle les pensées intrusives menacent des perceptions fondamentales du soi et de l’identité. Cette thèse a pour objectif d'examiner le lien entre l’égo-dystonie et les TCA. Pour se faire, nous avons exploré le lien entre la nature égo-dystone des obsessions chez les patients souffrant d'un TCA et la peur de l'image de soi. Nous avons également étudié la relation entre la sévérité des symptômes TCA et l’égo-dystonie dans les obsessions. En outre, nous avons investigué les différences dans la présence de pensées égo-dystones et de peur face à son identité entre des sujets non-cliniques et des personnes atteintes d’un TCA. Enfin, nous avons comparé le degré d’égo-dystonie dans les pensées de personnes atteintes d’un TCA à celui dans les pensées d’individus souffrant d’un TOC. L’égo-dystonie dans les pensées a été mesurée par l'Ego Dystonicity Questionnaire (EDQ) et le degré de peur face à l’identité a été mesuré par le Fear of Self Questionnaire (FSQ) d’une part dans un échantillon de femmes souffrant d’un TCA (n = 57) et d’autre part dans un échantillon de participantes non-cliniques (n = 45). Les résultats révèlent que l’égo-dystonie et la peur face à l’identité étaient fortement corrélées à la fois dans l’échantillon clinique et non-clinique. Les scores de l’EDQ n’étaient pas significativement corrélés à la sévérité des symptômes TCA à l'exception de la sous-échelle d’irrationalité de l’EDQ qui était fortement associée à la sévérité des comportements compulsifs compensatoires. Les participantes souffrant d'un TCA avaient des scores significativement plus élevés à l’EDQ et au FSQ que les sujets non-cliniques. Ensuite, une étude de cas décrit l’application du programme de thérapie cognitive TBI pour une femme de 35 ans avec un diagnostic de BN. La pathologie TCA s’est significativement améliorée au cours de la TBI et six mois suivant la thérapie. Cette étude de cas met en évidence l'importance de cibler les idées surévaluées, les doutes et le raisonnement face au soi et à l’identité dans le traitement psychologique pour les TCA. Enfin, l’objectif final de cette thèse était d’examiner les changements au niveau (1) des symptômes TCA, (2) du degré d’égo-syntonie dans les obsessions, et (3) des mesures de peur face à l’identité, de motivation, d’humeur et d’anxiété au cours de la TBI et au suivi post six mois. L’égo-dystonie, la peur face à l’identité, les symptômes TCA et le stade motivationnel ont été mesurés chez 15 femmes souffrant de BN au cours du traitement et six mois après la TBI. Quatre vingt pourcent de l’échantillon, soit 12 des 15 participantes, ont démontré une diminution cliniquement significative des symptômes TCA et 53% ont cessé leurs comportements compensatoires au suivi post six mois. Les retombées cliniques relatives au traitement des TCA sont discutées.

Determination of the nature of the diperiodatocuprate(III) species in aqueous alkaline medium through a kinetic and mechanistic study on the oxidation of iodide ion

The nature of the diperiodatocuprate(III) (DPC) species present in aqueous alkaline medium has been investigated by a kinetic and mechanistic study on the oxidation of iodide by DPC. The reaction kinetics were studied over the 1.0 ´ 10)3±0.1 mol dm)3 alkali range. The reaction order with respect to DPC, as well as iodide, was found to be unity when [DPC] [I)]. In the 1.0 ´ 10)3±1.0 ´ 10)2 mol dm)3 alkali region, the rate decreased with increase in the alkali concentration and a plot of the pseudo-®rst order rate constant, k versus 1/[OH)] was linear. Above 5.0 ´ 10)2 mol dm)3, a plot of k versus [OH)] was also linear with a non-zero intercept. An increase in ionic strength of the reaction mixtures showed no e ect on k at low alkali concentrations, whereas at high concentrations an increase in ionic strength leads to an increase in k. A plot of 1/k versus [periodate] was linear with an intercept in both alkali ranges. Iodine was found to accelerate the reaction at the three di erent alkali concentrations employed. The observed results indicated the following equilibria for DPC.

Glucoamylase immobilized on montmorillonite: influence of nature of binding on surface properties of clay-support and activity of enzyme

Glucoamylase was immobilized on acid activated montmorillonite clay via two different procedures namely adsorption and covalent binding. The immobilized enzymes were characterized by XRD, NMR and N2 adsorption measurements and the activity of immobilized glucoamylase for starch hydrolysis was determined in a batch reactor. XRD shows intercalation of enzyme into the clay matrix during both immobilization procedures. Intercalation occurs via the side chains of the amino acid residues, the entire polypeptide backbone being situated at the periphery of the clay matrix. 27Al NMR studies revealed the different nature of interaction of enzyme with the support for both immobilization techniques. N2 adsorption measurements indicated a sharp drop in surface area and pore volume for the covalently bound glucoamylase that suggested severe pore blockage. Activity studies were performed in a batch reactor. The adsorbed and covalently bound glucoamylase retained 49% and 66% activity of the free enzyme respectively. They showed enhanced pH and thermal stabilities. The immobilized enzymes also followed Michaelis–Menten kinetics. Km was greater than the free enzyme that was attributed to an effect of immobilization. The immobilized preparations demonstrated increased reusability as well as storage stability.

Existence of multiple attractors and the nature of bifurcations in a discontinuous logistic map

We present the analytical investigations on a logistic map with a discontinuity at the centre. An explanation for the bifurcation phenomenon in discontinuous systems is presented. We establish that whenever the elements of an n-cycle (n > 1) approach the discontinuities of the nth iterate of the map, a bifurcation other than the usual period-doubling one takes place. The periods of the cycles decrease in an arithmetic progression, as the control parameter is varied. The system also shows the presence of multiple attractors. Our results are verified by numerical experiments as well.

Martensitic transitions and the nature of ferromagnetism in the austenitic and martensitic states of Ni-Mn-Sn alloys

Structural and magnetic transformations in the Heusler-based system Ni0.50Mn0.50¿xSnx are studied by x-ray diffraction, optical microscopy, differential scanning calorimetry, and magnetization. The structural transformations are of austenitic-martensitic character. The austenite state has an L21 structure, whereas the structures of the martensite can be 10M , 14M , or L10 depending on the Sn composition. For samples that undergo martensitic transformations below and around room temperature, it is observed that the magnetic exchange in both parent and product phases is ferromagnetic, but the ferromagnetic exchange, characteristic of each phase, is found to be of different strength. This gives rise to different Curie temperatures for the austenitic and martensitic states.

The nature of Medicines

Created using the LLAC LOC tool, this includes links and activities with feedback. The content is an introduction to medicines for healthcare practitioners. It does not inlcude the Rights of Administration which are considered in separate LOC resource.