Pour déployer la quatrième génération de téléphonie 4G/LTE ou « LTE advanced », les opérateurs mobiles sont confrontés à de fortes contraintes : d’une part assurer une bonne couverture géographique mais aussi une excellente qualité de service. Ceci nécessite une ingénierie du réseau qui dépasse largement ce qui a été mis en place pour les réseaux GSM ou 3G. L’industrie des télécoms a créé pour cela le concept de « small cells » ou petites cellules qui viennent en renfort des « macrocells » ou grosses cellules. Cette thèse cherche à apporter une solution à cette problématique à travers notamment le développement d'antennes pour « smart cells ». Cette étude, supportée par le projet FUI NETCOM, doit permettre aux opérateurs d’étendre la couverture et la capacité de leurs réseaux à moindre coût tout en préservant la qualité de service. Pour cela, l’objectif plus précis de cette thèse est de concevoir un système multi-antennaire multistandard MIMO (Multiple-Input Multiple-Output) dédié à des noeuds relais pour le déploiement de la quatrième génération de téléphonie LTE. Cette conception doit être compatible avec 3 bandes de fréquences du LTE : (700-900 MHz) pour les bandes LTE 700 et LTE 800, (1710-1880 MHz) pour les bandes GSM 1800 / LTE 1800 et la dernière (2500-2690 MHz) pour le LTE 2600. Pour cela, nous avons étudié tout d’abord un système à 4 accès mono-bande, en nous concentrant uniquement sur la bande basse de 700 à 900 MHz. Dans une seconde étude, nous avons cherché à couvrir les deux autres bandes supérieures en nous servant d’éléments parasites pour constituer un système MIMO à 4 accès tri-bande. Nous avons ensuite étudié l’influence de l’environnement proche du système antennaire, avec la présence d’un radiateur métallique. Un problème important et fréquent dans les systèmes multi-antennes étant le couplage, nous avons également étudié et réalisé une technique de découplage. Celle-ci servira à isoler les éléments rayonnants à espacement réduit, conçus pour nos trois bandes LTE. / To deploy the fourth generation called 4G/LTE or "LTE advanced", mobile operators face strong constraints: they must ensure a good geographic coverage but also an excellent quality of service. This requires new methods that go far beyond what has been implemented for GSM or 3G networks. The telecom industry has created the concept of "small cells" that reinforce the "macrocells" deployed by the operators. This thesis tries to provide a solution to this problem and more particularly through the development of antennas for a product called "smart cell". This study, supported by the FUI project NETCOM, should enable mobile operators to extend the coverage and capacity of their networks at a lower cost while maintaining a good quality of service. To do that, the aim of this thesis more particularly is the design of a multi-band multi-antennas MIMO system (Multiple-Input Multiple-Output) dedicated to relay nodes for the deployment of the fourth generation 4G/LTE or "LTE advanced". The antenna design considers the coverage of the three LTE operating frequency bands and must be compatible with them. The (700-900 MHz) frequency band is used for the LTE 700 and LTE 800 bands, (1710-1880 MHz) for the GSM 1800/LTE 1800 bands and the last (2500-2690 MHz) for the LTE 2600 bands. In our first study, a reference system with 4 access was studied in simulation and measured, for only the low band 700-900 MHz. In a second study, we tried to cover the other two higher bands to have a tri-band system using the parasitic elements to get a three-band MIMO system with 4 access. We studied then, the influence of the environment close to the antenna system, with the presence of a metallic radiator. As we often encounter a frequent problem in multi-antenna systems which is the coupling problem between the different access of a multi antenna system, so we have studied and realized a decoupling technique. This technique was used to enhance the isolation between the different access.

A detecção microscópica de gametócitos pode subestimar sua prevalência e induzir uma avaliação errônea do potencial de transmissão da malária em áreas endêmicas, mantendo desconhecida a proporção de indivíduos infectados que são potenciais transmissores da doença. Este trabalho teve como objetivo a padronização de métodos moleculares para detecção e quantificação de gametócitos de P. falciparum e P. vivax. Descrevemos um método de qRT-PCR, que tem como alvo transcritos do gene pvs25 e pfs25. Detectamos transcritos de pvs25 em 96,4% das amostras sanguíneas provenientes de indivíduos infectados por P. vivax. qRT-PCR foi mais sensível do que a RT-PCR convencional, que tem como alvo o mesmo gene. Descobrimos que a maioria (61,9%) dos portadores de gametócitos são assintomáticos ou tem parasitemias subpatentes e não teriam sido detectados pelas estratégias de controle de rotina da malária. Porém, esses portadores de gametócitos não identificados, geralmente possuem baixas densidades de gametócitos e contribuem com até 4% da carga global de gametócitos na comunidade. / The microscopic detection of gametocytes may underestimate their prevalence, leading to an inaccurate assessment of the potential for malaria transmission in receptive areas and a poor estimate of the proportion of infected individuals who are infectious. We aimed to standardize molecular methods for detection and quantification of gametocytes of Plasmodium falciparum and Plasmodium vivax. Here, we describe a qRT-PCR that targets transcripts of the mature gametocyte-specific pvs25 gene. We found mature gametocytes in 53 of 55 (96.4%) P. vivax infections diagnosed during an ongoing cohort study in a farming settlement located in the southern of Amazonas state. SYBR green qRT-PCR was more sensitive than a conventional RT-PCR that targets the same gene. Most (61.9%) gametocyte carriers were either asymptomatic or had subpatent parasitemias, and would have been missed by routine malaria control strategies. However, potentially undiagnosed gametocyte carriers usually had low-density infections and contributed up to 4% to the overall gametocyte burden in the community.

Plastid genomes of photosynthetic flowering plants are usually highly conserved in both structure and gene content. However, the plastomes of parasitic and mycoheterotrophic plants may be released from selective constraint due to the reduction or loss of photosynthetic ability. Here we present the greatly reduced and highly divergent, yet functional, plastome of the nonphotosynthetic holoparasite Hydnora visseri (Hydnoraceae, Piperales). The plastome is 27 kb in length, with 24 genes encoding ribosomal proteins, ribosomal RNAs, tRNAs and a few non-bioenergetic genes, but no genes related to photosynthesis. The inverted repeat and the small single copy region are only ~1.5 kb, and intergenic regions have been drastically reduced. Despite extreme reduction, gene order and orientation are highly similar to the plastome of Piper cenocladum, a related photosynthetic plant in Piperales. Gene sequences in Hydnora are highly divergent and several complementary approaches using the highest possible sensitivity were required for identification and annotation of this plastome. Active transcription is detected for all of the protein coding genes in the plastid genome, and one of two introns is appropriately spliced out of rps12 transcripts. The whole genome shotgun read depth is 1,400X coverage for the plastome, while the mitochondrial genome is covered at 40X and the nuclear genome at 2X. Despite the extreme reduction of the genome and high sequence divergence, the presence of syntenic, long transcriptionally-active open reading frames with distant similarity to other plastid genomes and a high plastome stoichiometry relative to the mitochondrial and nuclear genomes suggests that the plastome remains functional in Hydnora visseri. A four stage model of gene reduction, including the potential for complete plastome loss, is proposed to account for the range of plastid genomes in nonphotosynthetic plants.

The diploma thesis deals with the modern design of the control circuits for digital potentiometers and their application in analog systems. The concept of the digital control is demonstrated on the electronically controlled active 2-nd order filter and programmable oscillator. The proposed design of the active filter describes a programmable active 2-nd order filter Sallen-Key. In this circuit it is possible independently programme cut-off frequency, Q factor and type of approximation with very good accuracy. The circuits of the designed filter and designed oscillator are simulated in PSpice (OrCAD), parasite effects and effects of the real parts are studied. Properties simulated circuits are compare with experimental results. These results appreciate quality and efficiency of the digitally controlled potentiometers in dependence on variable input circuit parameters. Integral part of this project is author’s universal control program called Digipot and comunications interface for many types of digital potentiometers with I2C, SPI or Up/Down interface. It is possible to use this device for many applications. The constructional details of the filter are presented at the end of this work. The software equipment is availability on enclosed CD.

In introduction of work, I presented the state of the art of measuring insertion loss of the EMI filter and the description of individual methods of measuring is also included. After that I dealt with global optimization methods and some of them I theoretically described. Mainly PSO method was studied carefully, and the principle of optimization in details are presented in the thesis, because this method was used for optimization of the filters parameters in the thesis. Next part of work deals with theoretical and mathematical expression of insertion loss of the EMI filters. Due to the mathematical expression of the insertion loss, the values of parasitic elements of given filter have been optimized in different measuring systems. This optimization was applied on synthetic data. By this step the functionality of optimization was proved and also the fitness function has been tuned and optimised. The last part of thesis works with optimization on measured data of given filters. I found out inaccuracy in mathematical expression of given model of EMI filter, therefore it was necessary to come up with the new filter model. The accuracy increases by using the new filter model. In next step the new model was enlarged by new spurious components.

Une des contraintes biotiques majeures de la riziculture de bas-fond au nord du Togo est l’adventice parasite Rhamphicarpa fistulosa (Hochst.) Benth. Afin d’évaluer les options stratégiques pour contrôler efficacement R. fistulosa, notre étude a été conduite avec comme principaux objectifs : 1) l’identification de la répartition de R. fistulosa et l’étude des facteurs qui favorisent son infestation, 2) l’étude de l’impact des niveaux d’infestation sur la flore adventice du riz, et 3) la caractérisation des interactions hôte-parasite et de leurs impacts sur le développement de l’hôte et les performances reproductives du parasite. A l’issu des prospections de terrain, les plus fortes infestations ont été retrouvées sur des sols majoritairement à texture sableuse et très pauvres en matière organique. Une flore adventice très diversifiée a été retrouvée en présence de R. fistulosa, certaines adventices pouvant être parasitées et constituer éventuellement un réservoir pour accroître le stock semencier du parasite. En conditions contrôlées, R. fistulosa se développe et se reproduit aussi bien sur le riz que sur la tomate, alors que le soja retarde la reproduction du parasite. La germination des graines de R. fistulosa est maximale en présence de graines de plantes cultivées ou adventices. Les graines nouvellement récoltées ont une dormance de plus de six mois, mais leur germination a été stimulée par la présence de phytohormones. En conclusion, les meilleures stratégies de lutte doivent impliquer le contrôle par les semis tardifs, les rotations culturales avec les légumineuses comme le soja, l’arachide ou le niébé, et les cultures maraîchères. / Main biotic constraints to rain-fed lowland rice cultivation in northern Togo include the parasitic weed Rhamphicarpa fistulosa (Hochst.) Benth. In order to evaluate efficient strategies to control R. fistulosa, our study was performed taking into account the following main objectives: 1) Identification of the distribution of R. fistulosa and study of the factors favouring its infestation, 2) Study of the impacts of infestation levels on rice weed communities, and 3) Characterization of the host-parasite interactions and their impacts on the host development and the parasite reproduction. Following fields investigations, highest infestations were observed on sandy soils with low levels of organic matter.In addition, weed flora found in the presence of R. fistulosa was much diversified and some weeds were found to been parasitized and could possibly constitute reservoirs to increase the seed stock of the parasite. In controlled experiments, R. fistulosa grown and reproduced better on rice and tomato crops, than on soybean which delayed the reproduction of the parasite. Germination of R. fistulosa seeds was stimulated in presence of cultivated crops or weeds. New collected seeds shown six months dormancy but their germination was stimulated in presence of phytohormones. In conclusion, the best strategies to control R. fistulosa must include delayed sowing, crop rotation with leguminous species (i.e. soybean, peanut or cowpea) and vegetable cropsKeywords: Rhamphicarpa fistulosa, rice, lowland, parasitism, host-parasite interaction, weeds.

Many virus infections induce a transient state of immune suppression in the infected host. Virus-induced T cell suppression can be caused by T cell activation-induced cell death (AICD), dendritic cell (DC) apoptosis, DC dysfunction, and/or the enhanced expression of immune-suppressive cytokines. It has been previously demonstrated that naïve bystander CD8 T cells derived from hosts experiencing an acute virus-specific T cell response underwent AICD when polyclonally activated by anti-CD3 in vitro (Zarozinski et al., 2000). Susceptibility of naïve bystander T cells to AICD could prevent the development of a new T cell response during an ongoing immune response, and thus render infected hosts immune suppressed. Although immune suppression could result in an enhanced susceptibility to superinfections, virus-infected individuals are more commonly resistant to superinfecting pathogens. Because of these seemingly contradictory conditions, we sought to investigate how acute viral infections impact naïve bystander CD8 T cells in vivo. More specifically, we asked whether bystander CD8 T cells are susceptible to immune suppression or whether they can contribute to the resistance to superinfections. In order to address this, we examined the responses of bystander CD8 T cells activated with cognate antigen during acute viral infections in vivo. We generated several in vivomodels using P14 (LCMV glycoprotein-specific), HY (male antigen-specific), and OT-I (ovalbumin-specific) transgenic CD8 T cells, which we defined as bystander during acute infections with lymphocytic choriomeningitis virus (LCMV), Pichinde virus (PV), vaccinia virus (VV), and murine cytomegalovirus (MCMV). Consistent with the enhanced susceptibility to cell death noted in vitro, we found that bystander CD8 T cells activated with cognate antigen in vivo during acute viral infections underwent markedly reduced proliferation. Virus-induced transient T cell suppression in vivo was not exclusively mediated by Fas-FasL- or TNF-induced AICD or due to an enhanced susceptibility to apoptosis. Instead, immune suppression in vivowas associated with a delayed onset of division, which we found not to be due to a defect in antigen presentation, but rather due to a T cell intrinsic defect. Despite the suppressed proliferation of TCR-stimulated bystander CD8 T cells in vivo, we found an enhancement of the effector functions exerted by bystander CD8 T cells activated during acute viral infections. During acute viral infections or after stimulation with type 1 IFN (IFN-αβ) inducers, some bystander CD8 T cells were sensitized to immediately exert effector functions such as IFN-γ production and degranulation upon stimulation with high affinity cognate antigen. Sensitization of naïve CD8 T cells required self-MHC I and indirect effects of IFN-αβ, while IL-12, IL-18, and IFN-γ were not individually required. IL-15 was not required for the rapid expression of IFN-γ, but was required for up-regulation of granzyme B (GrzB). P14 and OT-I CD8 T cells, which are capable of homeostatic proliferation, could be sensitized by poly(I:C), but HY CD8 T cells, which are poor at homeostatic proliferation, could not, suggesting that the requirement for MHC I may be to present low affinity cryptically cross-reactive self antigens. Sensitized naive CD8 T cells up-regulated the t-box transcription factor Eomesodermin (Eomes), which can regulate these rapid effector functions. In conclusion, we demonstrate in this thesis that acute viral infections impact naïve bystander CD8 T cells such that their response to cognate antigen is altered. Prior to cognate antigen engagement, bystander CD8 T cells up-regulated Eomes, CD122, and GrzB. Following cognate antigen engagement, bystander CD8 T cells rapidly degranulated and expressed the effector cytokine IFN-γ. The ability of bystander CD8 T cells to rapidly exert effector functions may contribute to the resistance of virus-infected individuals to superinfections. Despite these rapid effector functions, the proliferation of TCR-stimulated bystander CD8 T cells was markedly inhibited. This reduced proliferation was found not to be a defect in antigen presentation, but was a T cell intrinsic defect in initiating division. Thus, bystander CD8 T cells were also susceptible to virus-induced immune suppression. It is also likely that virus-specific CD8 T cells that are not activated until later in the response, so-called latecomer CD8 T cells, may also be susceptible to immune enhancement and suppression. Thus, latecomer CD8 T cells would be able to rapidly exert effector functions at the expense of proliferation. Taken together, we propose that during an immune response, due to spatial and temporal gradients of antigen and inflammation, it is likely that a combination of heterogeneous T cells with different signal strengths and sequences of exposure from cytokines and peptide-MHC constitute the total T cell response to pathogens.

Tato disertační práce prezentuje nový koncept kruhově polarizovaných anténních řad na bázi vlnovodu integrovaného do substrátu. Hlavní devízou konceptu je modularita, kdy je základní stavební blok řady použitelný pro tvorbu komplexnějších řad a tento blok zároveň slouží jako šablona pro návrh komplexnější struktury. Anténní řada byla simulována a experimentálně ověřena pro frekvence 17 a 60 GHz. Na základě dosažených výsledků byla odvozena metodologie pro návrh a identifikovány klíčové oblasti návrhu. Následně práce představuje techniku zvýšení šířky pásma osového poměru kruhově polarizovaných anténních řad pomoci parazitních flíčků, které jsou umístěny nad zářiče v definované vzdálenosti. Anténní řada z první části práce byla použita v simulacích a experimentálním ověření pro frekvence 17 a 60 GHz, kdy byla tato řada rozšířena o parazitní strukturu, přidávajíc další vrstvu modularity do konceptu.

This project is a reaction towards the static nature of the built world, and seeks to empower the end-user in the housing market by developing a highly customizable non-load bearing prefabricated panel system that allows for people to design, build, own, change and move their own apartments. It then explores the potential for it to resolve the current housing situation - both as new construction and through parasitic means (inhabiting parking garages, industrial buildings, renovation projects) - and the dynamics of user-defined living within society as a whole.

Gallium nitride (GaN) high-electron-mobility transistors (HEMTs) are favored for their smaller specific on-resistance, lower switching losses, and higher theoretical temperature limits as compared to traditional silicon (Si) power switches. They have the potential to dramatically increase the power density and efficiency of power electronics systems by replacing traditional Si-based switches. However, GaN HEMTs have a faster switching speed compared to their Si-based counterparts. Minimizing the parasitic loop inductances of the GaN HEMT package is crucial for reducing electromagnetic interference (EMI) noise and voltage spikes. Another concern with GaN HEMTs comes from their lower thermal conductivity and smaller die size. The HEMTs generally have a higher heat flux density, and accordingly, demand better heat dissipation. Thus, innovations are needed for making GaN HEMT packages with low parasitic inductances and higher thermal performances to further their applications in high-frequency, high-power-density converters. To reduce loop inductance, other researchers have embedded GaN HEMTs in a printed circuit board (PCB) and used plated vias for interconnections and heat dissipation. However, this approach requires more complex manufacturing steps and has lower thermal performance. This dissertation introduces different embedded packaging techniques for 650V, 150A GaN HEMTs; this method involves interconnecting the bare chips between direct-bonded copper (DBC) and a PCB or between two DBCs, as discussed in Chapter 2. Vertical interconnections by gold pins and silver rods are introduced and implemented in embedded packages to limit the parasitic loop inductance within 1.5 nH and parasitic resistances within 1.5 mΩ. The thermal performance of the embedded GaN HEMT packages is experimentally verified in Chapter 2; then, the junction-to-case thermal resistance (RthJC) measurement is discussed in Chapter 3. The common temperature-sensitive electrical parameters (TSEPs) of a GaN HEMT for junction temperature measurement lack sufficient sensitivity or stability due to the electron-trapping effect. The non-uniform distribution of the case temperature and a large temperature gradient between the case and heatsink also make it difficult to accurately measure the case temperature. In Chapter 3, gate-to-gate resistance (Rg2g) is selected as the TSEP for junction temperature measurement. The stacked thermal interface material (TIM) technique was used to reduce errors in case temperature measurement. This technique was implemented in a custom GaN HEMT package and in embedded GaN HEMT packages for measuring junction-to-case thermal resistance. The discrepancy between measurement and simulation is less than 20%, and the junction-to-case thermal resistance for embedded packages is within 0.1 °C/W. Chapter 4 evaluates the reliability of the GaN HEMT embedded packages developed in Chapter 2 by utilizing a power cycling test. Monitoring the junction temperature of the embedded packages online is challenging during the power cycling test. Other approaches have used the on-resistance as the TSEP in order to monitor junction temperature for GaN HEMTs but this is not accurate due to electron trapping. As discussed in Chapter 3, Rg2g is chosen as the TSEP to monitor the junction temperature without worrying about the influence of electron trapping, and this approach cycles the embedded packages at 75 A from 25°C to 125°C. The packages can endure 23,000 power cycles before failure. This work is the first to develop, fabricate, and characterize embedded packages for 650V, 150A GaN HEMT bare chips. These embedded packages with high-power-rated GaN HEMT bare dice provide an opportunity to reduce the number of paralleled power switches, reduce the system's cooling size, and increase the system's power density. In addition, this work is the first to develop the junction-to-case thermal resistance measurement technique by gate-to-gate electrical resistance and stacked-TIM for GaN HEMT packages. The technique helps enable solid thermal design for power electronics systems. / Doctor of Philosophy / Power switches are everywhere in our daily life. They are the fundamental elements in power converters for converting power to electric vehicles. As global power demand for these applications continues to increase, high levels of both efficiency and power density are crucial for power switches. However, traditional silicon-based switches are already very mature, and their properties are very close to their theoretical limits. For further improvement, researchers have tried to replace traditional Si switches with wide-bandgap switches, which have much higher theoretical limits. Gallium nitride high-electron-mobility transistors (GaN HEMTs) are one of the candidates. However, packaging these switches (GaN HEMTs) is challenging due to their initial properties. They naturally switch very quickly and have smaller sizes compared to traditional Si-based switches. The fast switching speed brings high dv/dt and di/dt during the switching period. It causes voltage spikes and electromagnetic interference (EMI) issues. And the smaller size contributes to higher heat flux density, thus requiring more efficient heat dissipation. To solve the challenge of packaging GaN HEMTs, this dissertation has developed embedded packaging techniques to achieve quiet switching and good heat dissipation. These packaging techniques enable GaN HEMTs' advantages and increase the power density and efficiency of power electronics systems. To experimentally verify the thermal performance of the embedded packages developed a junction-to-case thermal resistance measurement technique was introduced. The thermal resistance of a custom GaN HEMT package was measured, as were those of the embedded packages CPES also developed. The simulation results and the experimental results are close to each other. Finally, to further evaluate whether or not the newly developed embedded packages are reliable, power cycling tests were carried out at I = 75 A. The packages survived over 23,000 cycles before failure.