The commonest reproductive disorders of young men (namely low sperm counts, testicular germ cell cancer) may originate in fetal life similar to established disorders (cryptorchidism, hypospadias) that manifest at birth. These disorders are interlinked and may comprise a testicular dysgenesis syndrome (TDS), a concept supported by animal model studies. The latter have identified the likely time-frame within which TDS disorders may be induced, namely within the so-called masculinisation programming window (MPW). During this critical period, sufficient testosterone (androgen) must be produced by the fetal testis to program the male reproductive tract so that it will differentiate and grow normally after the MPW. Impaired androgen production or action within the MPW can result in smaller reproductive organs and their abnormal formation and function (e.g. cryptorchidism, hypospadias). The MPW is thus of fundamental importance in determining normal, or abnormal, male reproductive development and function for later life. There are two big unanswered questions about the MPW. First, what determines its timing? Second, what mechanisms are controlled by androgens specifically within this time-window and not at later time points? Three approaches were undertaken to address the first question experimentally in rats. First, investigation of whether the availability of androgens and or androgen receptors (AR) plays a role in determining the onset or ‘opening’ of the MPW. Second, investigation of whether the expression of AR co-regulators was a factor in determining androgen sensitivity during the MPW. Third, investigation of whether prostaglandins played a role in mediating androgen action in the MPW, as studies in the 1980s had suggested this possibility. To address what mechanisms are controlled by androgens specifically within the MPW, the expression of selected genes in the genital tubercle was investigated before, during and after the MPW in fetuses that had been exposed to treatments that modulated androgen action. Selection of genes was based on microarray studies and data reported in the literature (ie candidate genes). The studies reported in this thesis show that neither availability of androgens nor the AR are important in determining onset of the MPW, and providing exogenous androgens either prior to or during the MPW does not advance or enhance masculinisation. These studies also showed that females may have a slightly different window of susceptibility to androgen action than do males. Key AR co-regulators have been characterized in the male reproductive tract for the first time, two of which (BRG1, CBP) show changes in expression through development of the testis consistent with a role in Sertoli cells. Another AR co-regulator, RWDD1, was found to switch off in the absence of androgen action in the genital tubercle, pointing to a potential role during and/or after the MPW. Studies involving gestational exposure to indomethacin (a compound which inhibits prostaglandin synthesis) during the MPW showed no detectable effect on masculinisation. Finally, evaluation of candidate genes for mediating androgen action in the genital tubercle during the MPW, failed to identify their key involvement, thus they are unlikely to be involved in penis development and disorders such as hypospadias.

RFID has been characterized as a “disruptive technology” that has the potential to revolutionize numerous key sectors. A key advantage of passive RFID applications is the ability to wirelessly transmit automatic identification and related information using very little power. This paper presents an experimental investigation to inform the optimal configuration for programming passive ultra-high frequency (UHF) RFID media in dynamic applications. Dynamic programming solutions must be designed around the tag’s functionality, the physical programming configuration and environment. In this investigation, we present a methodology to determine an optimal configuration to maximize the systems programming efficiency for dynamic applications.

Les mémoires à nanocristaux de silicium sont considérées comme l'une des solutions les plus intéressantes pour remplacer les grilles flottantes dans les mémoires Flash pour des applications de mémoires non-volatiles embarquées. Ces nanocristaux sont intéressants pour leur compatibilité avec les technologies de procédé CMOS, et la réduction des coûts de fabrication. De plus, la taille des nanocristaux garantie un faible couplage entre les cellules et la robustesse contre les effets de SILC. L'un des principaux challenges pour les mémoires embarquées dans des applications mobiles et sans contact est l'amélioration de la consommation d'énergie afin de réduire les contraintes de design de cellules. Dans cette étude, nous présentons l'état de l'art des mémoires Flash à grille flottante et à nanocristaux de silicium. Sur ce dernier type de mémoire une optimisation des principaux paramètres technologiques a été effectuée pour permettre l'obtention d'une fenêtre de programmation compatible avec les applications à faible consommation d'énergie. L'étude s'attache à l'optimisation de la fiabilité de la cellule à nanocristaux de silicium. On présente pour la première fois une cellule fonctionnelle après un million de cycles d'écriture et effacement dans une large gamme de températures [-40°C;150°C], et qui est capable de retenir l'information pendant dix ans à 150°C. Enfin, une analyse de la consommation de courant et d'énergie durant la programmation montre l'adaptabilité de la cellule pour des applications à faible consommation. Toutes les données expérimentales ont été comparées avec les résultats d'une cellule standard à grille flottante pour montrer les améliorations apportées. / The silicon nanocrystal memories are one of the most attractive solutions to replace the Flash floating gate for nonvolatile memory embedded applications, especially for their high compatibility with CMOS process and the lower manufacturing cost. Moreover, the nanocrystal size guarantees a weak device-to-device coupling in an array configuration and, in addition, for this technology it has been shown the robustness against SILC. One of the main challenges for embedded memories in portable and contactless applications is to improve the energy consumption in order to reduce the design constraints. Today the application request is to use the Flash memories with both low voltage biases and fast programming operation. In this study, we present the state of the art of Flash floating gate memory cell and silicon nanocrystal memories. Concerning this latter device, we studied the effect of main technological parameters in order to optimize the cell performance. The aim was to achieve a satisfactory programming window for low energy applications. Furthermore, the silicon nanocrystal cell reliability has been investigated. We present for the first time a silicon nanocrystal memory cell with a good functioning after one million write/erase cycles, working on a wide range of temperature [-40°C; 150°C]. Moreover, ten years data retention at 150°C is extrapolated. Finally, the analysis concerning the current and energy consumption during the programming operation shows the opportunity to use the silicon nanocrystal cell for low power applications. All the experimental data have been compared with the results achieved on Flash floating gate memory, to show the performance improvement.