Doctor of Philosophy

dissertationAnimals have developed extraordinary capacities to maintain homeostasis in the face of severe osmoregulatory challenges from their environment. For instance, with respect to salt and water homeostasis, freshwater animals continuously eliminate excess water while conserving solutes, whereas land-dwelling organisms have to conserve water and solutes as much as possible. Comparative morphological studies suggest that animals have tackled the problems of excretion and osmoregulation by evolving a specialized structure: the excretory organ. Animal excretory organs are extremely diverse. Some are unicellular, such as the excretory cell in nematodes. Others are multicellular and highly specialized, such as the protonephridia/metanephridia in invertebrates or the kidneys in vertebrates. In light of such anatomical and functional diversity, the evolutionary origins of animal excretory systems pose an interesting question in biology. However, the hypotheses proposed thus far remain highly controversial for two main reasons. First, many evolutionary arguments are based solely on morphology in organisms for which no molecular data are available, precluding rigorous genetic comparisons. Second, while invertebrates are critical elements of this evolutionary puzzle, the molecularly tractable ones studied to date display highly derived excretory systems. C. elegans possesses a single excretory cell, while the ultrafiltration of nephrocytes is uncoupled from the absorption/secretion of Malpighian tubules in D. melanogaster. Comparative morphological studies have demonstrated the existence of more complex excretory organs amongst many other invertebrates, including planarians. Planarians have a protonephridial excretory system in which each protonephridial unit consists of a tubule, opening distally via a nephridiopore at the surface of the animal and ending proximally in one or more terminal structures called flame cells. Protonephridia are commonly found amongst many invertebrates. Since protonephridia combine ultrafiltration with filtrate modification, planarians close an "invertebrate gap" in the study of excretory system biology. Taking advantage of a rapidly expanding list of molecular tools in recent years, this dissertation project aims to perform a comprehensive molecular and functional study of planarian protonephridia in order to provide new insights into the longstanding question on the evolutionary relationship between vertebrate and invertebrate excretory systems and gauge planarians' potential as a novel invertebrate model for human kidney development and disease

EXPRESSION OF GLUTARYL7-AMINOCEPHALOSPORANIC ACID ACYLASE IN ESCHERICHIA COLI BL21(DE3) AND IMMOBILIZATION OF RECOMBINANT ENZYME ON NANOPOROUS MATERIALS

The synthesis of 7-ACA from cephalosporin C (CPC) by a two-step bioconversion using D-amino acid oxidase (DAAO) and glutaryl 7-ACA acylase (GLA) has been effectively and largely applied in pharmaceutical industry. In this study, the gene gla coding for 720-amino acid GLA from plasmid pUC57::gla was analyzed and successfully inserted into vector pET22b(+) to form expression vector pET22b(+)::gla. The newly constructed expression vector pET22b(+)::gla was cloned and then transformed into Escherichia coli BL21(DE3) to generate recombinant strain E. coli BL21(DE3)[pET22b(+)::gla]. The suitable conditions for expression of gla gene were in LB medium at 30 oC and induced by 0.4 mM of Isopropyl β-D-1-thiogalactopyranoside (IPTG) for 3 hours. Under the chosen culturing parameters, expression of gla gene by E. coli BL21(DE3)/[pET22b(+)::gla] resulted in a recombinant GLA (rGLA) with molecular weight of 83 kDa and catalytic activity of 2.7 U/mg of total protein. Experimental research on immobilization of rGLA onto ten nanoporous materials were showed that, SBA-15 was the best one for immobilization of rGLA, reaching activity of immobilized enzyme of 22.2 U/g matrix. Furthermore, optimal conditions of procedure for immobilizing rGLA on nanomaterials (SBA-15) were determined as follows: temperature is 25 °C, pH7.0 and immobilization time –60 minutes. Therefore the results reported in this study revealed the successfully heterologous expression of GLA in recombinant E. coli and potential immobilization of enzyme on inorganic nano-materials

Analyse des environnements supports à l'ingénierie collaborative synchrone à distance (approche ergonomique pour l'amélioration des outils via l'analyse des usages)

La conception de produits industriels complexes exige la collaboration de plusieurs acteurs de différents domaines et est distribuée géographiquement tout au long du processus de conception. Afin d'améliorer les résultats au regard du triptyque qualité, coût, délais et de la mondialisation des marchés, des concepteurs, distribués dans l'espace et dans le temps ont besoin d'un environnement de travail pour collaborer, afin de : créer une compréhension partagée entre les différents acteurs d'une équipe, les concepteurs doivent négocier et argumenter les solutions. partager des informations sur le produit entre différents métiers dans les étapes du processus de conception. synchroniser les différentes versions de modèles du produit entre les concepteurs. Le travail collaboratif s'organisant comme une alternance de travaux synchrones et asynchrones, nous souhaitons améliorer la continuité des flux d'informations entre ces différents modes de collaboration. Ceci passe par une amélioration des outils de communication technique en mode synchrone, et par la possibilité pour les concepteurs de synchroniser les versions de modèles modifiées en mode asynchrone. Ce deuxième point est obtenu par une identification de conflits entre version, et une facilitation du dialogue argumentatif synchrone afin de converger dans la négociation des choix de résolution de ces conflits. La démarche générale de la thèse se base sur la Design Research Methodology, basée sur une observation de situation industrielle et une analyse de scénarios d'usage, la proposition et le développement de nouveaux outils, et finalement une évaluation de l'utilisabilitéThe design of complex industrial products requires the collaboration of several actors of various domains and is geographically distributed throughout the process of design. To improve the results with regard to the triptych quality, cost, time and of the globalization of markets, designers, distributed in the space and in the time need a working environment to collaborate, to: To create an understanding shared between the various actors of a team, the designers have to negotiate and argue the solutions. Share information on the product between various trades in the stages of the process of design. Synchronize the various versions of models of the product between the designers. Collaborative design is organized as alternating synchronous and asynchronous work, we wish to improve continuity of information flow between these different modes of collaboration. This requires improved communication technology tools in synchronous mode, and the possibility for developers to synchronize models modified versions asynchronously. This second point is obtained by identifying conflicts between version, and facilitation of synchronous argumentative dialogue to converge in the negotiation of choice for resolving these conflicts.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Vietnamese rice exports: Do large destination markets stimulate?

What determines Vietnamese rice export flows? Data on rice export from Vietnam and its 124 destination markets in 2010 shows that high-income from agricultural sector of importing countries do not necessarily result in higher rice exports whereas exports tend to be higher to highly populated countries. In order to confirm the negative effect of the importing countries' GDP, We proceed to split the full sample into subsamples for Asian and non-Asian importing countries. While GDP covers the entire income of the whole economy, the value added agriculture performs better in determining the export pattern of firms operating in one sector. Specifically, distance in some cases encourages rice exports if destination markets are non-Asian countries implying a high export capacity of rice firms. For a heavy bulk good such as rice, the effect of landlocked dummy is far more sensitive to rice exports volume than exports value

Vietnamese rice exports: Do large destination markets stimulate?

What determines Vietnamese rice export flows? Data on rice export from Vietnam and its 124 destination markets in 2010 shows that high-income from agricultural sector of importing countries do not necessarily result in higher rice exports whereas exports tend to be higher to highly populated countries. In order to confirm the negative effect of the importing countries' GDP, We proceed to split the full sample into subsamples for Asian and non-Asian importing countries. While GDP covers the entire income of the whole economy, the value added agriculture performs better in determining the export pattern of firms operating in one sector. Specifically, distance in some cases encourages rice exports if destination markets are non-Asian countries implying a high export capacity of rice firms. For a heavy bulk good such as rice, the effect of landlocked dummy is far more sensitive to rice exports volume than exports value

Vietnamese footwear export: The direction of trade and determinants of firms’ market penetration

We investigate determinants of firms’ direction of trade by using panel data of Vietnam’s footwear firms for the 2006-2010 period. Since no variance was found between firms, a pooled multinomial logit model is consequently preferable. Notably, the economies of scale show positive and significant effects for footwear firms serving the USA and EU markets. Although Vietnamese footwear firms are less likely to export to the ASEAN countries, they tend to focus on the diversification of products in this market. Both private and FDI firms are less likely to export to the EU compared with their counter parts owned by the State (SOEs). However, private firms outperform SOES in the U.S market

Preschool STEM Activities and Associated Outcomes: A Scoping Review

This review highlights the need for further investigation into the benefits of STEM activities in preschool children’s learning, girls’ engagement and learning of children with disabilities in the STEM field. The review process involved accessing 19 relevant studies from Scopus, ERIC and Google Scholar databases in March 2023. Through the synthesis of information from these studies, seven STEM activities were identified as effective in enhancing preschool children’s learning: educational robots, educational games, argumentative interactions, inquiry-based learning and engineering design, drawing and telling about engineers, free play and pretend play, and group membership. Each of these activities contributes to different learning outcomes for children. Moreover, the review emphasizes the importance of role-playing activities ‘as if’ engineers and scientists, facilitated by teachers, in fostering girls’ motivation and engagement in the STEM field from an early age. Long-term scientific interventions at home have a significant positive impact on the science literacy skills of deaf children. The implications of this review are particularly relevant for early childhood educators, as it provides valuable insights into the use of STEM activities to enhance children’s learning outcomes

Using flat phosphor layer in dual-layer remote phosphor configuration to improve luminous efficacy

The phosphor layer shape and components distances are the subjects proposed to advance the quality of WLEDs in this article. The two distances, between phosphor layers (d1) and between the phosphor layer and the LED chip (d2) in Flat dual-remote phosphor (FDRP) and Concave dual-remote phosphor (CDRP) were examined by experiments to determine their impacts on WLEDs lighting performances. The results suggest that FDRP is a better option than CDRP for lighting performance. In each respective structure, the distances influence the lighting capacity and color output whenever they fluctuate. Therefore, to effectively control and study this phenomenon, the correlated color temperature is maintained at 8500 K, and the concentration of phosphor material is altered while the distances are changing. When d1 and d2 are at the starting value of 0, the recorded lumen output and chromatic performance of lighting devices are the lowest and begin to increase as d1 and d2 expand. Bigger d1 and d2 mean bigger scattering area and better chromatic light integration, which leads to higher color quality. Detailed results present that optimal values of d1 or d2 for the highest lumen output of 1020 lm are 0.08 mm or 0.63 mm, respectively. Meanwhile the lowest color deviation is accomplished with d1=0.64 mm or d2=1.35 mm

THE SITUATION OF MENTAL HEALTH OF VIETNAM DISABLED ATHLETES IN WEIGHTLIFTING AND JAVELIN BEFORE PARALYMPIC GAMES 2021

The purpose of this study was to find out the situation of Vietnam disabled athletes' mental health before Paralympic Games 2021. Seven athletes from the Vietnam disabled team (including 4 male and 3 female athletes in weightlifting and javelin contents) were chosen to identify their mental health before Paralympic Games. The International Olympic Committee's (IOC) Sports Metal Health Assessment Tool 1 (SMHAT-1) was used to determine the risk or experience of symptoms and mental health disorders of national team athletes with disabilities, facilitating timely referral for athletes in need of adequate support and treatment. The study identified the mental health of disabled Vietnam athletes in weightlifting and javelin. Thus, it led the management and coaches to have a specific plan for the appropriate pre-competition preparation for athletes, thereby getting good results in the upcoming Paralympic Games 2021.  Article visualizations