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The MIT Libraries is addressing the problem of maintaining and sharing digital content over the long haul with a project called DSpace. For this digital repository, a simple, open-source software application was built that not only accepts digital materials and makes them available on the Web but also puts them into a data management regime that helps to preserve them for generations to come. Other organizations worldwide have begun similar efforts including Cornell University, and the University of Toronto, the University of Cambridge. DSpace has a growing group of committed programmers distributed across the globe who continually maintain and improve it.

The amount of digital content produced at academic research institutions is large, and libraries and archives at these institutions have a responsibility to bring this digital material under curatorial control in order to manage and preserve it over time. But this is a daunting task with few proven models, requiring new technology, policies, procedures, core staff competencies, and cost models. The MIT Libraries are working with the DSpace(TM) open-source digital repository platform to explore the problem of capturing research and teaching material in any digital format and preserving it over time. By collaborating on this problem with other research institutions using the DSpace platform in the United States, the United Kingdom, Europe, and other parts of the world, as well as with other important efforts in the digital preservation arena, we are beginning to see ways of managing arbitrary digital content that might make digital preservation an achievable goal. / Page image PDF

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M.Sc. / Please refer to full text to view abstract

The refrigeration energy load in a modern day supermarket makes up a large proportion of the total energy bill. Better design of refrigerated display cases would reduce this load and also have a corresponding effect on the running costs of the refrigeration plant. Further enhancements such as the reduction of air overspill from the case would also influence the aisle temperatures and therefore the comfort levels in the store. This research project uses the technique of computational fluid dynamics (CFD) to investigate the contemporary design of a vertical multideck refrigerated display case. From a two dimensional computational model conclusions were drawn as to the principles of operation of the case. During the course of the project, a custom designed experimental facility was constructed, capable of testing the display case according to the relevant test standards. Using this facility, experimental validation was carried on a number of the design modifications to assess the actual refrigeration load against that predicted by the CFD model. The success of this validation allowed further work into the feasibility of certain design changes by making modifications to the CFD model. The work presented in this thesis makes a contribution to the global effort towards the reduction of the energy consumption by retail refrigeration systems. It does this by showing that possibilities do exist for an improvement in the energy efficiency of multideck refrigerated display cases and that CFD provides a useful tool towards this goal. It also demonstrates the design modifications which proved to yield a saving in energy. These were a reduction in the mass flow rate of air around the case, the inclusion of a honeycomb section on the air curtain outlet of the case the addition of a front upstand and the introduction of a second air curtain thus applying a velocity gradient across the curtain.

Résumé: Lorsqu’une femme en âge de reproduction est diagnostiquée avec un cancer du sein, le traitement comprend entre autres de la chimiothérapie et/ou une hormonothérapie. Malheureusement, certaines patientes deviendront infertiles suite à la chimiothérapie qui est gonadotoxique, ce qui diminue leurs chances de devenir mères avec leurs propres gamètes. Etant donné que la grossesse après un cancer du sein n’est plus considérée comme un facteur de risque de récidive de la maladie, l’accès à la maternité chez ces jeunes patientes est devenu un enjeu majeur. Cependant, peu de données ont été publiées concernant la sécurité de concevoir grâce à la PMA chez une patiente devenue infertile suite au traitement du cancer du sein.Il est donc primordial d’offrir aux femmes qui le désirent une méthode de préservation de la fertilité avant tout traitement gonadotoxique.La conservation d’ovocytes ou d’embryons après hyperstimulation ovarienne est une des techniques offertes aux patientes. Néanmoins, en cas de maladie hormono- sensible tel que le cancer du sein, une élévation d’hormones stéroïdiennes accompagnant la réponse ovarienne est peu souhaitable. Des protocoles modifiés ont donc été développés, tel que l’hyperstimulation ovarienne aux gonadotrophines associée au letrozole, un inhibiteur de l’aromatase.Malgré certains résultats rassurants dans la littérature, les données concernant l’efficacité et la sécurité de ce protocole sont toutefois limitées.Notre projet comporte 2 objectifs:1. Evaluation d’une procédure de préservation de la fertilité associant une hyperstimulation ovarienne au letrozole (Let-COH), dans une étude prospective non randomisée (BROVALE).2. Evaluation de la sécurité de la grossesse associée à la PMA chez des patientes ayant été traitées pour un cancer du sein.Dans la première partie nous avons confirmé l’efficacité du Let-COH sur base du taux de maturation ovocytaire similaire à une population contrôle de patientes7infertiles ayant bénéficié d’une hyperstimulation ovarienne conventionnelle sans letrozole (groupe contrôle) quel que soient les modes de déclenchement de la maturation ovocytaires utilisés, human chorionic gonadotropin (hCG) ou l’agoniste de la gonadotropin-releasing hormone (GnRHa). Par ailleurs, les modifications endocriniennes dans le liquide folliculaire, et l’expression de gènes liés à la qualité ovocytaire au niveau des cellules du cumulus oophorus (CC) ont été analysées. Dans le microenvironnement entourant l’ovocyte, nous avons observé un taux d’œstradiol significativement plus bas et un taux de testostérone significativement plus élevé dans le groupe Let-COH, comparé au groupe contrôle. Par ailleurs, l’expression génique au niveau des CC était plus basse dans le groupe Let-COH déclenché à l’hCG comparé au groupe contrôle. Cependant l’inverse était observé lorsque le GnRHa était utilisé comme déclencheur de l’ovulation. Ces résultats suggèrent donc un effet bénéfique des analogues de la GnRH sur la qualité ovocytaire avec le Let-COH.Nous avons montré que le taux d’oestradiol était bas durant la stimulation, mais que le taux de progestérone durant la phase lutéale était supra-physiologique chez les patientes ayant reçu le Let-COH, comparable au taux des patientes contrôles.Etant donné le rôle potentiel de la progestérone dans la carcinogenèse mammaire, nous avons modifié le protocole de déclenchement de l’ovulation, pour administrer le GnRHa au lieu de l’hCG.Dans la seconde partie de notre travail, nous avons réalisé une étude rétrospective multicentrique afin de comparer les issues oncologiques et de grossesse de patientes ayant été enceintes après cancer du sein, naturellement (n=173) ou grâce à la PMA (n=25). Malgré la petite taille de l’échantillon obtenu, nous n’avons pas observé plus de récidives chez les patientes ayant eu recours à la PMA.En conclusion, ce projet nous a permis de démontrer l’efficacité de la préservation de la fertilité chez les jeunes patientes atteintes de cancer du sein, par hyperstimulation associée au letrozole. Nous avons également observé que le risque de récidive de la maladie n’était pas majoré dans notre échantillon limité de patientes enceintes suite à la PMA après cancer du sein. / Abstract:Young women diagnosed with breast cancer are often treated with adjuvant primary therapy, including chemo and/or endocrine therapy. These women may face infertility or premature ovarian failure due to the gonadotoxicity of chemotherapy regimens or to aging, which significantly decreases their chances to become mothers with their own gametes. Since it has been established that pregnancy after breast cancer does not increase the risk of relapse, assisting young breast cancer survivors to access motherhood has become a major quality of life issue. However, data on the safety of pregnancies associated with ART in patients who became infertile are scarce. Therefore, it is recommended that young patients diagnosed with breast cancer be informed about treatment-related infertility risks and available procedures to preserve their fertility before undergoing gonadotoxic treatment.Oocyte and/or embryo cryopreservation following controlled ovarian hyperstimulation (COH) is the most established fertility preservation procedure that patients can undergo before initiation of chemotherapy. However, this procedure induces an increase in steroid levels, which may be detrimental in hormonally sensitive diseases such as breast cancer. In order to avoid this issue, a modified protocol has been developed a decade ago, combining letrozole (an aromatase inhibitor) with conventional COH (Let-COH).Despite recent reassuring preliminary results reported in the literature, data are still very limited regarding the efficiency and the safety of this protocol.Thus, the aims of this project were:1. Evaluation of the efficiency of Let-COH before adjuvant therapy, in anonrandomized prospective study (BROVALE).2. Evaluation of the safety of ART-associated pregnancy in breast cancersurvivors.In the first part, we confirmed the efficiency of Let-COH (study group) based on similar oocyte maturation rates when compared to infertile patients undergoing conventional COH without letrozole (control group), regardless of the triggering5method, human chorionic gonadotropin (hCG) or GnRH-agonist (GnRHa). Oocyte quality was indirectly assessed by analysis of follicular fluid (FF) steroid levels and cumulus cell (CC) gene expression (HAS2, PTGS2, and GREM1). We found that estradiol levels were significantly lower and testosterone levels significantly higher in the study compared to the control group, suggesting lower oocyte quality. Nevertheless, when GnRHa was used as ovulation trigger, differences in estradiol levels between the groups were reduced. Similarly, CC gene expression was lower in the study group compared to the control group in the hCG triggered subpopulation, while the opposite effect was observed in the GnRH-agonist triggered subpopulation. Altogether, the results suggest a benefit of GnRHa trigger on oocyte quality in Let- COH protocol.The safety of the protocol was assessed by measuring estradiol and progesterone levels during and after Let-COH. We confirmed that estradiol levels remained low during treatment. However, during luteal phase, progesterone levels were comparable to conventional COH when triggered with hCG, but not with GnRHa. Since progesterone may be as important as estradiol in promoting breast carcinogenesis, we modified the protocol to systematically use GnRH-agonist as ovulation trigger.In the second part of our project, we conducted a retrospective multicenter study to compare pregnancy and oncological outcomes among breast cancer survivors who subsequently conceived spontaneously (n=173) or following ART (n=25). Although the ART group’s sample size was small, we did not observe an increased relapse rate after ART compared to patients who conceived naturally.In conclusion, we confirmed the feasibility and efficiency of Let-COH as a method of fertility preservation in breast cancer patients. Moreover, in our small series of ART- associated pregnancies in breast cancer survivors we did not observe an increased risk of disease recurrence. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

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Historic landscapes are vital elements of our nation's cultural continuum and must be protected as a part of living fabric of the community. This thesis addressed the preservation of historic landscape gardens, focusing on design strategies that can make historic time legible in landscape. It proposed a landscape plan for the preservation of Palm Cottage Garden in Gotha, Florida, a significant historic landscape resource. To determine the criteria used to establish how and to what period the estate should be restored, the Secretary of the Interior's Guidelines for the Treatment of Cultural Landscapes was followed. This process involved documenting the current site conditions and evaluating natural and cultural resources. For the garden to continue to keep its historic fabric, rehabilitation was selected. The garden was designed to preserve existing features and make efficient contemporary use of the garden possible. The landscape plan focused on strategies that reveal the site's significant past through new design elements while adapting to current and future needs.