Despite the tremendous bandwidth increase in 3rd generation (3G) Broadband Wireless Networks (BWNs) such as Universal Mobile Telecommunication System (UMTS), maintaining the mobile users’ Quality of Service (QoS) requirements while maximizing the network operators’ revenues is still a challenging issue. Moreover, spatial distribution of network traffic has a negative impact on the overall network performance where network resources are overutilized in parts of the network coverage area while such resources are underutilized in other network coverage areas. Therefore, network congestion and traffic imbalance become inevitable. Hence, efficient Radio Resource Management (RRM) techniques which release congestion and balance network traffic are of utmost need for the success of such wireless cellular systems. Congestion control and load balancing in BWNs are, however, challenging tasks due to the complexity of these systems and the multiple dimensions that need to be taken into consideration. Examples of such issues include the diverse QoS requirements of the supported multimedia services, the interference level in the system, which vary the mobile users and base stations allocated transmission powers and transmission rates to guarantee certain QoS levels during the lifetime of mobile users connections. In this thesis, we address the problem of congestion control and load balancing in BWNs and propose efficient network coverage adaptation solution in order to deal with these issues, and hence enhance the QoS support in these systems. Specifically, we propose a directional coverage adaptation framework for BWNs. The framework is designed to dynamically vary the coverage level of network cells to release system congestion and balance traffic load by forcing mobile users handoff from a loaded cell to its nearby lightly loaded cell. The framework consists of three related components, namely directional coverage adaptation module, congestion control and load balancing protocol, and QoS provisioning module. These components interact with each other to release system congestion, balance network load, maximize network resource utilization, while maintaining the required QoS parameters for individual mobile users. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2009-04-24 12:15:54.582

Today, different types of cellular networks are actively working on the radio links. For instance, the Global System for Mobile Communication (GSM) is being used in nearly two hundred countries and currently it has around two and half billion users all over the world. Universal Mobile Telecommunication System (UMTS) is currently deployed in many countries and it is providing increased data rates, coverage and mobility as compared to GSM. Wireless Local Area Networks (WLAN) are very famous when we have a small area and none real time services. Worldwide Interoperability for Microwave Access (WiMAX) is a new technology and it is in deployment phase. In all these cellular technologies, we have very limited recourses and we have to make best use of them by proper management. Radio Resource Management (RRM) is a control mechanism for the overall system which is being used to manage radio resources in the air interface inside a cellular network. The main objective is to utilize the available spectral resources as efficiently as possible. Our aim is to use them in the best possible way to maximize the performance and spectral efficiency in such a way that we have maximum number of users in our network and Quality of Service (QoS) is up to the mark. In a cellular communication system, a service area or a geographical region is divided into a number of cells and each cell is served by an infrastructure element called the base station which works through a radio interface. The frequency license fees, real estate, distribution network and maintenance are the issues which dominates the cost for deploying a cellular network. Management of radio related resources is a critical design component in cellular communications. In RRM, we control parameters like Radio Frequency (RF) planning, link budgeting, modulation schemes, channel access schemes etc. RF planning includes cell planning, coverage of the network and capacity of the network. Our main focus in this thesis will be on cell planning and link budgeting and we will discuss them in context of a WiMAX network.

In this study, it was experimentally proved, for the first time, that it is possible to predict the frequency of electromagnetic radiation that can modulate activity of proteins and more specifically activity of enzymes. The prediction was obtained using the computational model so called the Resonant Recognition Model (RRM). The model was tested here experimentally using the reaction catalysed with the enzyme l-lactate dehydrogenase (LDH). The RRM model was applied to the group of the enzymes belonging to the sub-subclass EC 1.1.1.27 i.e. l-lactate dehydrogenase. The wavelengths of the electro magnetic radiation calculated by the RRM and proposed to alternate activity of l-lactate dehydrogenate were identified at =620 25 nm and =840 25 nm. Enzyme activity was then measured after the exposure to the low-intensity, electromagnetic radiation (EMR) within the proposed EMR range [560-860 nm]. The experimental results have indeed shown that there is a significant increase in the activity of LDH only after irradiation within the range of the frequencies predicted by the RRM: 596nm (12%; P less than 0.001) and 829 nm (11.8%, P less than 0.001). These results prove successfully that activity of proteins and more specifically enzymes could be modified by EMR radiation of specific frequencies and even more that RRM computational model can successfully predict these frequencies.

Hur företag förhåller sig till rankinglistor tros enligt tidigare forskning bero på ett proaktivt agerande från företagens sida för att motverka risken att dras med ett dåligt rykte, vilket är något som företagsledare i dag ser som den mest oroande risken. Ryktet kan ses som en reaktion på ett företags arbete utifrån uppfattningar från dess intressenter gällande företagets beteende. Dessa reaktioner och uppfattningar kan tydliggöras genom bland annat rankingar och andra mätningar. Syftet med denna uppsats är att öka förståelsen för hur företag förhåller sig till rankinglistor. Undersökningen utgår från Sustainable Brand Insights (SBI) årliga index över Sveriges mest hållbara varumärke och genomfördes genom intervjuer med sex av de 20 högst rankade företagen, samt SBI. Studien visar för det första att företagen förhåller sig olika till rankingen. För det andra att det hållbara arbetet är nära knutet till kärnverksamheten och för det tredje att rankingen inte har någon inverkan på hur företagen arbetar med hållbarhet.

Oskar (Osk) is a posterior body patterning determinant in Drosophila melanogaster oocytes. oskar (osk) mRNA is translationally repressed until it reaches the posterior of the oocyte where Osk protein accumulates. Translational repression of osk prior to posterior localization is mediated by the RNA binding protein, Bruno (Bru). To better define Bru binding sites, I performed in vitro selections using full length Bru and the fragments containing either the first two RRMs (RRM1+2) or the third RRM (RRM3+). The aptamers from the final round from each of the selections produced a multitude of overrepresented primary sequence motifs. Examples of each of these motifs were found in the 3’UTRs of the mRNAs that Bru is known to regulate during oogenesis. GFP reporter transgenes under the control of the UAS-Gal4 expression system were constructed with each class of the binding sites within the reporter transgenes’ 3’UTRs to test the motifs’ ability to repress the reporters in vivo. In a wildtype background, the GFP reporters containing the binding sites were translationally repressed. In the aret mutant background, the GFP levels of the repressed GFP reporters increased with reduced Bru activity, suggesting the transgenes’ repression is mediated by Bru. Three of the motifs isolated in the in vitro selections reside in the AB and C regions of the osk 3’UTR, and the three classes of sites were mutated in the AB and C regions. The mutated AB and C regions were used to assay for a reduction of Bru binding affinity for the mutant RNAs. Additionally, the mutations were incorporated into an osk genomic transgene that was introduced into an osk RNA null as well as an Osk protein null background. The mutations reduced Bru binding to the AB and C regions. The transgenes containing the mutated Bru binding sites could not fully rescue the osk RNA null phenotype but can fully rescue the Osk protein null phenotype, suggesting an osk transcript can regulate other osk mRNAs in trans. / text

The differences between networks of mobile operators can be in their achitecture or the optimization of each network. The architecture is standardized which means there will only be differences in the willingness of mobile operators to invest in newer network elements. Network optimization is more important. The way of optimization isn't strictly given and depends on how the operator deals with it. The most important attribute in optimization is balance. The operators try to achieve balance among three important parameters. Those are capacity, coverage and maintaining QoS. Optimization depends on RRM algorithms. The algorithms include various functions such as admission control, congestion control, handover control, power control, etc. These elements don’t only affect the optimization but also affect each other, because they cooperate with each other. For example, an incorrect admission control of the network leads either to frequent network congestion because of a large number of participants in the network (participants are dissatisfied with the services offered by the operator) or to low utilization of the network because of too few participants in the network (the operator is dissatisfied because he is losing the possible earnings). Neither of these posibilities is good for the mobile operator, therefore it is important that the admission control is well balanced.

Dans les cellules eucaryotes, l’expression d’un gène peut être régulée à de nombreux niveaux. Les études réalisées sur le contrôle de l’expression génique se sont généralement intéressées aux mécanismes de contrôle transcriptionnel. Cependant de nombreux exemples mettent de plus en plus en évidence l’importance des mécanismes post-transcriptionnels dans cette régulation. Les contrôles post-transcriptionnels de l’expression génique reposent essentiellement sur des interactions spécifiques entre les régions 5’ et 3’ non traduites de l’ARNm et des protéines agissant en trans qui contrôlent spécifiquement la maturation des ARNs messagers (ARNms), leur localisation cytoplasmique, leur stabilité et/ou leur traduction. Les éléments riches en adénine et en uridine (ARE), localisés dans la région 3’ non traduite de nombreux ARNms, font partie des séquences régulatrices les plus étudiées. Elles sont notamment présentes dans les ARNms codant pour des cytokines et des proto-oncogènes. Les protéines de liaison à l’ARN jouent donc un rôle central dans la régulation de l’expression des gènes. Les protéines TIA-1 et TIAR appartiennent à la famille des protéines qui fixent l’ARN et qui contiennent des domaines RRM (RNA Recognition Motif). Elles sont impliquées dans des mécanismes permettant la régulation de l’expression génique tels que l’épissage alternatif et la traduction. En particulier, elles participent à l’arrêt général de la traduction qui accompagne un stress environnemental en séquestrant les ARNms poly(A)+ non traduits dans des foci cytoplasmiques appelés granules de stress (SGs). Elles sont également impliquées dans la répression traductionnelle d’ARNms spécifiques en liant les ARE présents dans les extrémités 3’ non traduites de certains ARNms, et notamment des ARNs messagers codant pour le TNF-α et la cyclooxygénase-2 (Cox-2). L’invalidation des gènes tia-1 et tiar chez la souris conduit à une létalité embryonnaire élevée suggérant que ces protéines jouent également un rôle important au cours de l’embryogenèse. Afin de comprendre les mécanismes par lesquels les protéines TIA-1 et TIAR remplissent leurs différentes fonctions, nous avons réalisé un criblage par la technique du double hybride en levure afin d'identifier des partenaires d’interaction de ces deux protéines. Les protéines TIA-1 et TIAR interagissent avec les protéines FBPs (Fuse Binding Proteins). Celles-ci participent notamment à la maturation et à la dégradation des ARNs. Nous avons montré que les protéines FBPs co-localisent parfaitement avec TIA-1 dans le noyau et migrent dans les granules de stress en réponse à un stress oxydatif. De plus, des expériences de retard de migration sur gel réalisées à partir d’extrait cytosolique de macrophages ont montré que les protéines FBPs sont présentes dans le même complexe liant l’ARE du TNF-α que TIA-1. Enfin, la surexpression du domaine de liaison à l’ARN KH3 de FBP2 en fusion à l’EGFP induit la séquestration spécifique des protéines TIA-1 et TIAR dans des foci cytoplasmiques, empêchant ainsi leur accumulation nucléaire. Nos résultats indiquent que les protéines TIA-1/R et FBPs pourraient être fonctionnellement impliquées dans des étapes communes du métabolisme de l’ARN dans le noyau et/ou le cytoplasme.

A radio resource management scheme for WCDMA uplinks is proposed that manages quality of service (QoS) for heterogeneous services whilst maintaining high channel utilisation efficiency. The proposed system is partitioned into the 3 modules, viz. a QoS-sensitive rate scheduler, an inter-service and intra-service user prioritisation schemes, and a frame admission controller for dynamic resource reallocation. Users are allocated the minimum resources required to manage their QoS requirements through just-in-time delivery of payload, leaving more room for best-effort service users. The transmission urgency of each user is estimated by the rate scheduler based on a target transmission delay - a unique parameter used in the proposed resource management strategy to enable just-in-time payload delivery, service differentiation, and uncomplicated mapping of application requirements to QoS parameters. Transmission rate change requests from the rate schedulers are collectively processed through inter-service and intra-service priority queuing in a manner that is shown to exhibit fairness in allocation of resources amongst users of a heavily loaded network. The performance of the proposed strategy is explored through discrete-event simulations for 3 classes of traffic - voice, video and data, over the WCDMA uplink in the presence of short-term Rayleigh fading, ARQ, FEC, target transmission delays and FER targets in a multi-cell environment. Two alternatives for distributed resource management have been studied, with the UE or Node-B in control of resource allocation. The UE controlled resource management system is shown to achieve higher channel utilisation efficiency at the cost of fairness. The Node-B controlled resource manager respects the priority of speech, video and data traffic in heavily loaded systems, as reflected in 95 percentile packet transmission delays. / PhD Doctorate

Post-transcriptional regulations (PTRs) have always been considered features of organisms with higher complexity. However recently, the interest toward the post- transcriptional mechanisms in prokaryotes increased. The bacterial proteome is much more complex compared to the genome size, suggesting a tight and articulate regulation of proteins production, extremely important for the bacterial adaptation to an always changing environment. Bacterial PTRs are responsible of modulation of mRNA stability and decay, translation initiation and elongation, modulation of the access of ribosome to the ribosome binding site and control of termination of the transcript. The main actors in the PTRs are small non-coding RNA (responsible of the inhibition of the transcription) and RNA binding proteins (RBPs), which modulate the translation and half-life of the mRNA. RBPs, are particularly of my interest since I wanted to find a possible orthologous of the eukaryotic Elav-like (Elavl) family of proteins in Acinetobacter baumannii. Elav-like proteins are present in all metazoans and are characterized by two highly conserved sequences: RNP-1 (a quite well conserved hexamer) and RNP-2 (a really well conserved octamer) that are responsible of binding to the mRNA. Each species has a different number of Elavl paralogous that is totally independent from the complexity of the organisms, suggesting a more ancient origin. In particular, I focused on the human paralog HuR (human antigen R). HuR is characterized by three RNA Recognition motif (RRM) -domains, is ubiquitously expressed and is mainly localized into the nucleus (where it is responsible of maturation of the mRNA), but under stress stimuli, can shuttle into the cytoplasm where protect the target mRNA from degradation, by binding AU/U rich sequences (ARE sequences). Its high concentration into the cytoplasm can lead to the overexpression of oncogenes and pro-tumorigenic factors. The choice of Acinetobacter baumannii comes from the increasing worldwide concern toward this pathogen that is becoming multidrug resistant. Indeed, in Italy, more the 50% of nosocomial infections are caused by A. baumannii. I found a putative protein (AB-Elavl), composed by a single RRM domain endowed with similar features of the eukaryotic RRM domain as the presence of a quite well conserved RNP-2 and a less conserved RNP-1. I expressed this protein with recombinant tools and confirmed the production of the protein in the host by western blot and mass spectrometry. I evaluated the binding activity of AB-Elavl testing the EC50 and the Kd with different biochemical assays (EMSA, AlphaScreen and HTRF- FRET) toward three different RNA sequences, in order to test the specificity. By X- RAY and NMR, I confirmed the folded structure that can be overlapped to the HuR’s one and the interaction with the probes tested, highlighting the presence of binding, but with different specificity. I also tested some small molecules developed for interfering in the binding of HuR with the target sequence and found a possible compound able to interact with AB-Elavl, by disrupting the binding with the target probe. All these results suggest an ancient origin of the metazoans’ Elavl family of proteins that probably share a common ancestor with AB-Elavl. More studies should be performed to better understand the role of AB-Elavl in A. baumannii as well as in other bacteria. In fact, I found the presence of other ARE sequence-binding proteins also in Pseudomonas aeruginosa. Interesting would be to check the presence of this protein in all the multidrug resistant ESKAPE bacteria.

No / This paper presents a Master/Slave redundancy mechanism for the airborne Integrated Modular Radio to improve the reliability of the joint radio resource management (JRRM) system. The proposed mechanism adopts keep-alive heart beat messages and real time information synchronization to ensure a smooth switchover in the event of a platform failure. To enhance the scalability and decoupling of the system, the proposed hot swap solution makes the JRRM switchover transparent to both the higher layers and the lower layers. The experiment results and the performance obtained from the test-bed has proved the validity of the solution.