La thèse « l’argent dans les Métamorphoses d’Apulée » est le fruit d’une accumulation de recherches. Apulée nous a paru de suite comme un auteur représentant plus d’une énigme entre sa vie et ses œuvres. Au lieu de faire le point sur les seuls sujets présents dans l’œuvre, nous avons choisi de nous concentrer sur les objets. L’argent nous est apparu comme un objet récurrent sous bien des formes. Nous avons dressé un relevé aussi complet que possible. Il nous a paru essentiel de rechercher l’origine étymologique de chacun. L’idée était de faire apparaître le sens du mot en lui-même et son utilisation en contexte. Quelle vision de l’argent et de la société pouvions-nous en tirer ? Utiliser un terme est effectuer un choix qu’un Romain de l’époque d’Apulée pouvait comprendre. C’était renvoyer à des concepts, à des positionnements, des réflexions qui faisaient sens à l’époque de l’œuvre. A alors surgi la question de l’époque et de la société d’Apulée. Dans quelle mesure l’univers économique et social du IIème siècle ap. J.-C. dépeint fictivement dans les Métamorphoses rejoignait-il la réalité de cette époque ? Restait pourtant un domaine bien difficile à manipuler : celui de la religion. Le domaine religieux n’apparaît pas seulement dans le livre XI. Entre les références à la magie, les cultes locaux, le recours à des pratiques magiques, les religions de Rome et de Grèce, les religions orientales… Dans quelle mesure cette thématique entre-t-elle en relation avec l’argent ? Finalement, l’argent semble participer à la construction de sens d’interprétation différents. C’est un des symboles qui permet des lectures renouvelées des Métamorphoses. / The thesis "Money in Apuleius’ Metamorphoses" is the result of an accumulation of research. Apuleius appeared to us immediately as an author representing more than one enigma between his life and his works. Instead of taking stock of the only subjects present in the work, we chose to focus on objects. Money has appeared to us as a recurring object in many forms. We have made a record as complete as possible. It seemed essential to us to seek the etymological origin of each one. The idea was to bring out the meaning of the word itself and its use in context. What vision of money and society could we draw from it? To use a term is to make a choice that a Roman of the time of Apuleius could understand. It was referring to concepts, positions, reflections that made sense at the time of the work. Then arose the question of the time and society of Apuleius. To what extent the economic and social world of the 2nd century AD J. - C. depicts fictitiously in the Metamorphoses it joined the reality of this time? However, there was one area that was difficult to manipulate: that of religion. The religious domain does not appear only in the book XI. Between the references to the magic, the local cults, the recourse to magic practices, the religions of Rome and Greece, the Eastern religions ... To what extent does this theme have any relationship with money? Finally, money seems to participate in the construction of different interpretations. It is one of the symbols that allow renewed readings of the Metamorphoses.

Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.

<p>The initiation of metamorphosis causes the cessation of the larval growth period which determines the final body size of adult insects. Because larval growth is roughly exponential, differences in timing the initiation of metamorphosis can cause large differences body size. Although many of the processes involved in metamorphosis have been well characterized, little is known about how the timing of the initiation of metamorphosis is determined. </p> <p>Using different strains from <italic>Tribolium castaneum<italic>, <italic>Tribolium freemani<italic>, and <italic>Manduca sexta<italic> and varied nutritional conditions, I was able to document the existence of a threshold size, which determines when the larva becomes competent to metamorphose. Threshold size, however, does not dictate the exact timing of initiation. The exact timing for the initiation of metamorphosis is determined by a pulse of the molting hormone, ecdysone, but only after threshold size has been reached. Ecdysone pulses before the larva attains threshold size only cause the larva to molt to another larval instar. These results indicate the timing of metamorphosis initiation is controlled by two factors: (1) attainment of threshold size, at which the larva becomes competent to initiate metamorphosis and (2) the timing of an ecdysone pulse after attaining threshold size. </p> <p>I hypothesize the attainment of threshold size, and therefore competence to metamorphose, is mediated by the effect of changing juvenile hormone concentrations caused by the increase in size of the larva. While the larval body grows nearly exponentially, the corpora allata, which secretes juvenile hormone, grows very little if at all. The difference in relative growth causes juvenile hormone concentrations to gradually become diluted. When juvenile hormone concentrations fall below a threshold, changes in protein-protein binding occur that can cause changes in signaling networks and ultimately gene expression. These changes make the larva competent for metamorphosis. </p> <p>I have demonstrated that only threshold size is consistently correlated with body size; other growth parameters such as growth rate, duration of instars, or number of instars do not consistently correlate with variation in body size. Using the black mutant strain of <italic>M. sexta<italic> I have shown that lower juvenile hormone titers correlate with lower threshold sizes. My hypothesis is consistent with the large body of literature indicating the involvement of juvenile hormone. I also hypothesize that the diversity of metamorphosis types in holometabolous insects can be explained by heterochronic shifts in the timing of threshold size and other developmental events related to metamorphosis. The heterochronic shifts affect not only the morphology of organs, but can also affect the overall phenotypic response of the larva to changes in the environment. The different phenotypic responses among species may make the more or less suited for certain types of niches.</p> / Dissertation

Originallly presented as the author's Thesis--Harvard, 1971. / Includes bibliographical references (p. 107-114) and index.

Η μεταμόρφωση (metamorphosis), το πέρασμα δηλαδή των ψαριών από το στάδιο της ιχθυονύμφης στο στάδιο του ιχθυδίου (juvenile), συνδέεται με αλλαγές στη μορφολογία, την αύξηση, τη συμπεριφορά και το ενδιαίτημα, οι οποίες είναι καθοριστικές για την επιβίωση των ατόμων και συνεπώς για τη δομή και τη δυναμική του πληθυσμού στον οποίο πρόκειται να ενσωματωθούν. Στην παρούσα εργασία μελετήθηκε η φάση της μεταμόρφωσης σε τέσσερα είδη της οικογένειας Sparidae με την ταυτόχρονη εξέταση της μορφομετρίας και της μορφολογίας συγκεκριμένων χαρακτήρων. Τα είδη που εξετάστηκαν ήταν τα Oblada melanura (μελανούρι), Diplodus puntazzo (μυτάκι), Diplodus vulgaris (σαργόπαπας ή κακαρέλος) και Diplodus sargus (σαργός). Τα αποτελέσματα της μελέτης, έδειξαν πως με τη μεθοδολογία που ακολουθήθηκε, η φάση της μεταμόρφωσης μπορεί να προσδιοριστεί ικανοποιητικά και να οριστεί ένα μέσο μήκος μεταμόρφωσης. Αποκαλύφθηκαν επίσης διαφορές και ομοιότητες στην αλλομετρική αύξηση των ειδών που εξετάστηκαν, καθώς και ισχυρή συσχέτιση της αλλομετρικής αύξησης με την πρόσφατη θερμοκρασιακή ιστορία του περιβάλλοντος ανάπτυξής για το στάδιο πριν το εκτιμηθέν μέσο μήκος μεταμόρφωσης του κάθε είδους. Τα αποτελέσματα, συζητούνται σε σχέση με τις οικολογικές απαιτήσεις των ψαριών κατά τη μετάβαση από την πελαγική στη βενθική διαβίωση. / During metamorphosis, fish undergo major changes in morphology and growth followed by shifts in behavior and habitat use. In this study, metamorphosis was examined on the early life stages of four Sparidae species, by analyzing their allometric growth patterns concurrently with the evolution of specific morphological characters. The species examined were Oblada melanura (saddled seabream), Diplodus puntazzo (sharpsnout seabream), Diplodus vulgaris (common two-banded seabream) και Diplodus sargus (white seabream). Our results showed that metamorphosis can be adequately defined and an average length at metamorphosis can be estimated, with the use of the methodology proposed. Moreover, specific patterns of allometric growth were detected within each species, as well as, a strong correlation of allometric growth with recent environment temperature, for the stage before the estimated average metamorphosis length. Results are discussed in terms of the ecological demands of fish during their transition from the pelagic to the benthic/coastal existence.

Στην παρούσα εργασία μελετήθηκε α) η επίδραση της θερμοκρασίας άσκησης στην κολυμβητική ικανότητα των μεταμορφούμενων ατόμων σαργού (Diplodus sargus) και μελανουριού (Oblada melanura), β) η συμβολή των μυών και του σχήματος του σώματος στην κολυμβητική ικανότητα κάθε είδους, και γ) η επίδραση της θερμοκρασία διαβίωσης στο ρυθμό αύξησης και επιβίωσης κάθε είδους. Τα αποτελέσματα της παρούσας εργασίας συζητούνται ως προς τη σημασία της κολυμβητικής ικανότητας κατά τη φάση της μεταμόρφωσης, καθώς και συγκριτικά με τα αποτελέσματα άλλων εργασιών για την επίδραση της θερμοκρασίας στην ταχύτητα κολύμβησης, στο ρυθμό αύξησης και επιβίωσης των ψαριών. / The present study examined a) the effect of exercise temperature on swimming performance of white seabream (Diplodus sargus sargus) and saddled seabream (Oblada melanura) juveniles, b) the contribution of muscles and body shape on swimming performance of each species and c) the effect of temperature on growth rate and survival of each species. The results of the present study are discussed with respect to the importance of swimming performance during the metamorphosis stage and are compared to the results of other studies concerning the effect of temperature on swimming speed, growth rate and survival of fish.

Magistro darbe atlikta teorinė specialiųjų poreikių vaikų ugdymo proceso bendrojo lavinimo mokykloje ir metaforinio mąstymo patarlėmis ypatumų analizė. Tyrimo hipotezė: tikėtina, kad specialiųjų ugdymosi poreikių mokinių metaforinio mąstymo lygmuo yra žemesnis nei bendraamžių ir tai siejasi su didaktinio proceso ypatumais, todėl sistemingas ir kryptingas mokymas suprasti patarlių perkeltinę prasmę lavins ir spartins metaforinio mąstymo vystymąsi. Tyrimo metodai: mokytojų ir mokinių anketinė apklausa; ugdomasis eksperimentas; duomenų apdorojimas. Tyrime dalyvavo 52 pradinių klasių mokytojai ir 644 mokiniai iš Marijampolės ir Vilkaviškio bendrojo lavinimo mokyklų. Eksperimentiniame tyrime dalyvavo 10 trečios ir 12 ketvirtos klasės specialiųjų ugdymosi poreikių turinčių mokinių iš Vilkaviškio Salomėjos Nėries vidurinės mokyklos. Empirinėje dalyje nagrinėjama: mokinių perkeltinės patarlių prasmės supratimas; mokymo metodų taikymas metaforinio mąstymo lavinimui; metaforinio mąstymo ugdymo rezultatai. Empirinio tyrimo išvados: 1. Inkliuzinio ugdymo idėjos ir heterogeninis mokinių grupavimas lemia ne tik poreikių įvairovę klasėje, bet ir reikalauja individualizuoto požiūrio parenkant ir taikant mokymo metodus, būdus, kurie užtikrintų, kad kiekvienas mokinys įgytų tvirtas žinias, būtų formuojama jo pasaulėžiūra, savarankiškumo įgūdžiai bei lavinami intelektinai gebėjimai. Vienu iš intelektinių gebėjimų galime laikyti metaforinių tekstų – patarlių, supratimą. Heterogeninės klasės... [toliau žr. visą tekstą] / In work of the master was leading the theoretical analysis of features of properties of thinking with metamorphoses of proverbs for process of education of children with special needs. Hypothesis of research: there is an opinion, that for education of pupils with special needs of metamorphosis of thinking the level is below rather than at their schoolfellows and it is connected with didactic of process features, therefore the purposeful and regular doctrine of understanding of proverbs in a portable kind been educate and will accelerate development of metamorphosis a level of thinking. Methods of research: questionnaire of teachers and pupils; educational experiment; data processing. 52 teachers of initial classes participated in research and 644 pupils from comprehensive schools from Marijampoles and Vilkaviskis. In experiment research was participated the ten of third class and twelve pupils from fourth class having special need of education from Vilkaviskio Salomejos Neries high school. In empirical part it has been investigated: portable concept of sense of a proverb pupils; use of methods of training for development of metamorphosis thinking; results of research of metamorphosis thinking. The conclusions of research of metamorphosis thinking: 1. Ideas of inclusive education and the heterogeneous pupils of grouping defines not only a version in a class but also demands an individual sight choosing and using methods of training, kinds which would provide that each pupil... [to full text]

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The ING (INhibitor of Growth) tumor suppressor genes are conserved from yeast to humans and are implicated in several processes important to cell proliferation and apoptosis. ING proteins contain a plant homeodomain (PHD) finger that suggests these proteins may modulate transcription factor-mediated pathways. Little is known about the mechanism of action of INGs, especially in the context of normal development. The ING family of proteins includes at least five different genes, ING1-ING5, with evidence for alternate promoter usage and splicing that generate multiple isoforms. To elucidate the role of ING in different tissues to modulate function, I used amphibian metamorphosis as a model system in which a single stimulus, thyroid hormone (TH), initiates apoptosis, proliferation, and remodeling in the tail, hindlimb, and brain, respectively. I discovered seven ING1 and three ING2 transcript variants in Xenopus laevis and investigated their expression patterns. High expression levels of most variants were found in adult brain, testis, and eye. During natural metamorphosis or precocious metamorphosis induced by treating tadpoles with exogenous TH, ING1 and ING2 transcript variant levels were differentially regulated in a tissue-specific manner. Some variant levels increased with the induction of apoptosis of the tail, while levels of the same variants decreased upon induction of proliferation and differentiation in the hindlimb. Although levels of all INC variants were relatively high in whole brain, they did not change during metamorphosis or TH treatment. Given that ING has previously been shown to modulate apoptosis, it is likely that upregulation of specific isoforms may contribute to the tissue-specific TH-mediated response in the tail, and that downregulation facilitates proliferation of the hindlimb. To further investigate the hypothesis that ING is regulated by TH, an analysis of 1NG1 and ING2 genomic sequences was carried out. Promoter sequences for each variant were determined and putative thyroid hormone response elements (TREs) located. To test whether thyroid hormone receptors associate with these elements, chromatin immunoprecipitations (ChIP) assays were done on tail homogenates from premetamorphic tadpoles treated with TH or vehicle control. Both thyroid hormone receptor α (TRα) and thyroid hormone receptor β (TRβ) differentially associate with ING1 and ING2 promoter regions. TR association increased significantly on promoters for ING variant transcripts that increase upon TH treatment, and decreased significantly on promoters for ING variant transcripts that decrease upon TH treatment. ChIPs also showed that ING associates with TH-regulated promoters including TRβ, TH-Responsive Basic Leucine Zipper Transcription Factor (TH/bZIP), ING1 and ING2. Furthermore, TR and ING were shown to co-immunoprecipitate with both purified proteins and using total tail homogenates from metamorphic tadpoles. The antibodies used for these experiments were made against Xenopus TRβ and ING2 and were characterized as part of this thesis. Bioinformatics revealed that TREs are present in promoters of ING genes for other species including human, mouse, and a related frog species, Xenopus tropicalis; therefore, it is likely that modulation by TH is a conserved mechanism of ING regulation. These data suggest that there may be antagonistic regulation of ING transcript variants by TH that correlates with tissue fate. TRs associate with ING promoters, and ING is associated with TR-regulated promoters. Moreover, TR and ING proteins co-immunoprecipitate. It is therefore likely that TR and ING are co-regulators of gene expression during TH-dependent tadpole metamorphosis. This thesis contributes to the understanding of ING which is relevant to elucidating many disease states, as well as being critical in understanding the role of this tumor suppressor in the context of TH regulation and normal development.

Nanoparticles (NPs) are engineered in the nanoscale (<100nm) to have unique physico-chemical properties from their bulk counterparts. Nanosilver (nAg) is the most prevalent nanoparticle in consumer products due to its strong antimicrobial action and can be released to the environment during product manufacture, usage and disposal. The predicted environmental concentrations are within the North American guidelines for the protection of aquatic life and in drinking water. While nAg toxicity at high concentrations has been well described, the sublethal effects at environmentally-relevant concentrations are relatively unknown. Initial screening in our lab showed nAg was a potential endocrine disrupting chemical (EDC). Amphibian metamorphosis is mediated by thyroid hormone (TH), and nAg perturbed TH-dependent transcriptional responses in the tailfin of bullfrog (Rana catesbeiana) tadpoles. The primary objective of this thesis was to further investigate and characterize the effects of low, environmentally relevant concentrations of nAg on TH-dependent metamorphosis in R. catesbeiana and Xenopus laevis. Two chronic, 28 day in vivo exposures at 0.06 and 6µg/L nAg were conducted with premetamorphic R. catesbeiana tadpoles using TH to induce precocious metamorphosis. Ionic silver (iAg) was also examined to control for the complete dissolution of Ag. Analysis of metamorphic stage progression demonstrated nAg-induced acceleration of hindlimb growth and development. After 6 days of nAg exposure, analysis with quantitative real-time polymerase chain reaction (QPCR) demonstrated nAg-induced disruption of TH-responsive transcripts in a tissue-specific manner. Furthermore, the nAg effects could not be fully explained by iAg, indicating NP-specific disruption. Two chronic, 28 day exposures to 0.018-1.8 µg/L nAg were conducted on X. laevis premetamorphic and prometamorphic tadpoles. nAg was found to significantly bioaccumulate in tadpole tissue after 28 days. Furthermore, nAg increased the hindlimb length during early premetamorphosis and in post-metamorphic juvenile tadpoles. Using an in-house MAGEX microarray and QPCR transcriptional analysis, 7 biomarkers of nAg exposure were validated. Five of these targets showed disruption to their TH-response. Furthermore, the increased mRNA abundance of two peroxidases indicated that nAg generated reactive oxygen species (ROS) even at low, environmental concentrations. This thesis demonstrates that nAg has consistent EDC actions across two distinct amphibian species, and the data suggest that regulatory guidelines for silver may need revision. A X. laevis derived fibroblast-like TH-responsive cell line, XTC-2, was used in conjunction with the 7 biomarkers of nAg exposure to gain mechanistic insight into the role of ROS in TH signaling disruption. Monocultures were created and validated to increase the specificity of TH-response. While the monocultures were successfully created, the biomarkers were not responsive to nAg in this cell line. Additional investigations were made into the relationship between genetic sex and responsiveness to TH. Genetic sexing methods were used to investigate transcriptional differences between males and females during natural and TH-induced metamorphosis. The sexing protocol was optimized and validated successfully. The genetic sex was determined for premetamorphic and prometamorphic X. laevis tadpoles exposed to TH for 48 h. QPCR and microarray analysis were used to identify three markers that demonstrated transcriptional sex-bias during early gonadal differentiation stages. / Graduate / 0307 / 0383 / 0487 / amanda_carew14@yahoo.ca