No description available.

The Pseudomonas aeruginosa algG gene product is a mannuronan C5-epimerase, which converts mannuronate to guluronate residues within the polysaccharide, alginate. The aim of this work was to purii' the epimerase and determine optimum reaction conditions for its enzymic activity. The epimerase was produced as an over-expressed fusion protein, GST/algG, which was purified by affinity chromatography. Subsequent cleavage of algO from GST produced a yield of 36 % purified epimerase. A poly mannuronate substrate for the epimerase was produced from a mutant strain of Ps. aeruginosa (FRD462). To enable the poly mannuronate to act as substrate for the epimerase it was deacetylated, deacetylation was confirmed by infrared spectroscopy. Activity of the purified epimerase was demonstrated by NMR spectroscopy, and by a coupled assay, which coupled the epimerase activity to the activity of a guluronate specific lyase. Lyase activity was shown to be dependent on environmental conditions and could therefore not be used in the coupled assay to determine optimal conditions for epimerase activity. An assay for epimerase activity was developed from the micro-phenol/sulphuric acid assay of Chang (Chang et aL, 1998). This assay showed activation of the epimerase at low levels of Ca2 (in the range 3 mM -18 mlvi) with higher concentrations showing inhibition. In contrast, higher concentrations of Mg 2 (of the order of 18 mlvi) were needed to induce epimerase activity but no inhibitory effects were observed. Activation of the enzyme was induced by K concentrations in the range 1.5 mM - 8 mlvi, whilst the presence of Ne appeared to have no effect on epimerase activity. These results also suggested that the mannuronan C5-epimerase brings about conversion of the mannuronate residues within the alginate chain by a preferred or processive attack on substrate. Substrate viscosity was found to have an effect on the rate of epimerisation; increased viscosity led to lower activity.

All inbred strains of mice carry the Ren-1 structural gene, which encodes the renin-1 isozyme, the classical renin activity found in kidneys. In addition, some strains carry a second renin structural gene, Ren-2, which encodes the predominantly expressed SMG rennin isozyme, renin-2. Ren-1 and Ren-2 exhibit markedly different patterns of tissue- specific expression. In an effort to understand the molecular basis for this differential expression, a detailed analysis of the transcripts originating from these loci was undertaken. S1 analysis of SMG and kidney RNA populations indicated that the majority of transcripts initiate at one major site on Ren-1 and Ren-2. Interestingly a minor fraction of transcripts in the SMG initiate at two upstream sites. These transcripts encode an upstream ORF which is in frame with that of the renin precursor. The precise tissue-specificities of Ren-1 and Ren-2 were also examined: in the kidney, SMG, and also in several extrarenal tissues, since there is increasing evidence of renin expression in a number of extrarenal sites. To distinguish between the two highly homologous transcripts, an assay was developed exploiting established base sequence differences between Ren-1 and Ren-2 mRNA's by extension of a primer downstream of such a base difference in the presence of the appropriate ddNTP. Using this assay, Ren-1 and Ren-2 were found to be equally well expressed in the kidney, whereas in the SMG only Ren-2 is efficiently expressed. Interestingly in the other extrarenal tissues examined, testis, liver and heart, it is the Ren-1 allele that is preferentially expressed. The assay was also able to demonstrate the similarity in response of Ren-l/Ren-2 to certain physiological stimuli, such as sodium depletion. Thus, this study of the regulation of mouse renin gene expression has demonstrated further striking differences in the tissue-specific expression of Ren-l/Ren-2, and added to the increasingly compelling evidence of extrarenal renin gene expression.

The aim of this work was to implement and compare several activity recognition algorithms which could be used in a smart home environment and would be able to determine the current activity of an observed subject (virtual agent) in the smart home using only data gathered by elementary observations of the environment. Such algorithms are useful in several areas, for example to improve behavior of various virtual agents, making them more aware of actions of the other agents. The algorithms used in this thesis are based on Dynamic Bayesian Networks and have ability to determine whether the observed activity has been completed or just interrupted. An easily extensible 3D interactive simulator of a smart home environment was created to meet the needs of activity recognition and used to gather data for the learning and testing phases of the algorithms. The test subjects were human-controlled virtual agents.

M.Ed. (Education Management) / Please refer to full text to view abstract

No description available.

No description available.

Early menopause, the cessation of menstrual function before age 45, occurs in 10% of women, and is associated with higher premature mortality and increased risk of cardiovascular disease. Lifestyle factors like physical activity may influence menopause timing, but results from prior research are inconsistent. We evaluated the association between physical activity and the occurrence of early natural menopause in the Nurses’ Health Study II. Premenopausal women were followed prospectively from 1989 to 2011. Menopause status was self-reported biennially. Time per week participating in specific activities was reported every four years and used to calculate metabolic task hours (MET). Moderate and vigorous activity in adolescence and young adulthood was reported in 1997. We used Cox proportional hazards model to evaluate the association between physical activity and incidence of natural menopause before age 45 controlling for potential confounding factors. We observed no significant association between adulthood physical activity and early menopause. For example, compared to women with/wk, the hazard ratio for women in the highest category (≥42 MET h/wk) of cumulatively-averaged total physical activity was 0.90 (95% confidence interval: 0.76-1.07; P-trend: 0.63). Similarly, activity in adolescence and young adulthood were unrelated to risk. Body mass index did not modify the relation of physical activity and early menopause. Our findings suggest that physical activity is not associated with incident early menopause.

Le décrochage scolaire est un processus impliquant des facteurs multiples dont la qualité de la relation élève-enseignant n'est pas des moindres. Investir, ou simplement supporter, la relation à l'enseignant en période adolescente ''ne va pas de soi'', notamment parce que cela solliciterait un intense travail d'élaboration de la dynamique passivité-activité : passivité du côté de l'être (dé)formé, affecté, séduit par l'autre enseignant et dépendant de celui-ci; et activité du côté de l'emprise, de l'appropriation subjective et de la création adolescente. Nous proposons dans la présente thèse d'étudier l'hypothèse selon laquelle l'adolescent inscrit dans un processus de décrochage scolaire serait particulièrement en difficulté pour opérer ce travail d'élaboration de la dynamique activité-passivité tant au niveau intrapsychique que dans la relation intersubjective avec les enseignants. Dans cette perspective nous avons rencontré 17 collégiens âgés de 13 à 16 ans inscrits pour la plupart dans des structures de type classe relais. Nous nous sommes également entretenu avec deux enseignantes de classe relais. Notre méthodologie de recherche combine plusieurs outils : l'entretien, les tests projectifs du TAT et du Rorschach, le dessin et quelques observations in situ. Nous observons que la majorité des sujets acceptent, voire investissent, la position passive sur les plans interconnectés des affects (être affecté par l'autre) et de la dépendance dans le rapport à l'enseignant. Ils semblent cependant tenir à préserver et cultiver la position active de celui qui touche affectivement l'enseignant. La dynamique activité-passivité est marquée par un défaut d'élaboration de la fantasmatique de séduction qui semble ressurgir sur la scène de la classe à travers des conflits entre l'élève et l'enseignant. Nous discutons des enjeux de ces analyses pour la pratique clinique et pédagogique auprès des adolescents et pré-adolescents inscrits dans un processus de décrochage scolaire. / School dropout is a process that implies multiple factors, not the least of which is the quality of the teacher-pupil relationship. To invest or to simply put up with this relationship with the teacher during adolescence is not "obvious” at all, especially because it calls upon an intense work of elaboration of the activity-passivity dynamics : passivity from the one who is (de)formed, affected, seduced by the other (the teacher); and activity represented as grip, subjective appropriation and teenage creation. Our purpose in the present thesis is to study the hypothesis according to which teenagers who dropout from school cannot mentally elaborate the activity-passivity dynamics both on the intrapsychic level and that of the intersubjective relationship with teachers. To do so, we met 17 high school students from 13 to 16 years old registered in special classes for marginalized school children (called“classes relais” in French). We also conducted interviews with two teachers operating in those special classes. Our research method combines interviews, administering TAT and Rorschach’s projective tests, drawings and few in situ observations. We notice that most of the participants accepted, even invested the passive position from the perspective of both the interconnected affects (to be affected by the other) and the dependency to the teacher. However, it seems that they want to keep and improve the active position of the one who affectively touches the teacher. The activity-passivity dynamics is marked by a lack of elaboration of the seduction fantasy that spring up in the classroom through conflicts between pupils and teachers. These analyses are discussed in terms of the issues at stake for the clinical and educational practice for adolescents and pre-adolescents in the process of dropout.

BACKGROUND: Physical activity for the majority of individuals is below recommended levels despite strong evidence of its significant health benefits. Activity tracker devices present as a promising and affordable tool to help promote physical activity and active choices. Additionally, young adults present as an ideal age group to implement behavior change interventions. OBJECTIVE: To determine what features of activity tracker hardware and software are helpful in motivating active choices. METHODS: This cross-sectional study included 149 participants ranging in age from 18-29 years old who wore an ActiGraph GT3X+ accelerometer for one week. They then continued to wear the accelerometer in addition to a randomly assigned activity tracker (Apple Watch, Fitbit Surge, Basis Peak, or Microsoft Band 2) for an additional week. They also used the corresponding app for their activity tracker. Participants filled out a survey about their experience at the end of the study RESULTS: Overall hardware rating (p = 0.162) and overall software rating (p = 0.125) did not differ between the four devices. Degree of motivation of the hardware (p = 0.177) and software (p = 0.120) was also similar for all the activity trackers. There were 625 positive comments made about tracker hardware with the majority of these comments concerning mode options (n = 149), other (n = 94), and battery (n = 79). There were 287 positive software comments with the majority in the categories of other (n = 78) and information (n = 68). CONCLUSIONS: The analyses of our data did not show a significant difference between devices in any category. Furthermore, results indicated a high number of positive comments for both hardware and software overall. Users also reported device hardware and software to be personally motivating.