A geração de expressão de referência (GER) é um dos principais componentes de aplicações de geração de língua natural a partir de dados não linguísticos. Trabalhos existentes nesta área tendem a se concentrar em domínios bidimensionais e tridimensionais simples. Domínios mais realistas, entretanto, ainda são pouco explorados pela literatura, possivelmente pela dificuldade em produzir modelos computacionais com o grau de complexidade exigido. O recente surgimento de aplicações baseadas em ambientes interativos tridimensionais, todavia, oferece uma ampla gama de oportunidades de pesquisa em GER. Nesse trabalho apresentamos um algoritmo de GER para seleção de atributos espaciais em ambientes interativos tridimensionais do tipo GIVE. A solução proposta é uma extensão de um algoritmo de GER tradicional que utiliza relações espaciais combinado com conhecimento linguístico extraído de corpora e modelos computacionais de referência espacial. Essa solução foi avaliada de forma intrínseca no domínio de instruções em mundos virtuais. / Referring expressions generation (REG) is one of the main components in the generation of Natural Language from non-linguistic data. Existing work in the eld tends to focus on simple two- or three-dimensional domains. More realistic domains, however, are still little investigated, possibly due to the diculties in producing computational models with the required degree of complexity. The recent rise of applications based on three-dimensional interactive environments, however, oers a wide range of research opportunities in REG. In this work we present a REG algorithm for selecting spatial attributes in three-dimensional interactive environments GIVE. The proposed solution is an extension of a traditional REG algorithm that makes use of spatial relations combined with linguistic knowledge extracted from corpora and computational models of spatial reference. The proposal was evaluated intrinsically in the domain of instructions generation in virtual worlds.

Den här rapporten tog sin början i det faktum att många företag och organisationer idag inte är insatta i vad IPv6 innebär och hur de ska gå tillväga för att implementera IPv6. Det fanns vid tillfället ingen komplett metod för hur en analys av ett nätverk gick till, vad som var viktigt att tänka på, vilka tekniker som fanns tillgängliga och hur dessa implementerades. För att underlätta framtida övergångar till IPv6 bestämde vi oss för att utveckla en generell metod som användaren kan följa och läsa sig till vad de behöver tänka på vid varje steg. Metoden ger också exempel på hur användaren kan göra analyser och undersökningar som leder fram till en lösning som kan fungera för deras behov. Metoden besvarade frågeställningen ”Vad behöver ett företag göra för att kunna implementera IPv6 i en existerande nätverksmiljö?” Övergången till IPv6 är igång och många tekniker är inte färdigutvecklade. För att ta fram lösningar som fungerar för olika scenarier gjordes efterforskningar på både IP version fyra och version sex samt vilka övergångs-tekniker som är att rekommendera. Ett antal övergångs-tekniker valdes ut och sattes upp i ett testlabb där IPv6-funktionaliteten verifierades. För att ta fram en metod som täckte upp de vanligaste scenarierna diskuterades frågan med Empir AB, ett företag som arbetar med IT-lösningar och som tillhandahåller egna tjänster. Deras nätverk analyserades och det arbetet låg till grund för utformningen av metoden. Eftersom alla tekniker i metoden testades i laborations-nätverket fastställdes IPv6-funktionalitet genom att testa olika tjänster över nätverket. Testerna visade att det var fullt möjligt att implementera IPv6 efter en steg för steg-modell. Resultatet av arbetet kan användas för att initiera och fullfölja en övergång till IPv6 då användaren har en metod att följa, rekommendationer på vad som behöver göras och föreslagna lösningar som kan implementeras enligt anvisningar. / This report began with the fact that many companies and organizations today do not have any or little knowledge about IPv6 and what it means, nor do they know how to implement it. At the time of writing there were no complete method for how an analysis of a network were done, what was important to think on and which techniques were available. To ease future transitions to IPv6, we decided to develop a general method that a user could follow step by step, with instructions for what to think on at each step. The method also gives examples on how the user could do an analysis and examinations, and it eventually leads to a solution based on their needs. The method answers the question "what does a company need to do to be able to implement IPv6 in an already existing network?" The transition to IPv6 is happening and many techniques is still in development. To be able to present solutions that work with different needs, research in IP version four, version six and in transfer techniques were done as well. A set of transfer techniques was chosen and set up in a lab network where IPv6 functionality was verified. To develop a method that covered most of the common scenarios, the question were discussed with Empir AB, a company that works with IT solutions that hosts their own services. Their network was analyzed and the result was the foundation for the method. Since all techniques in the method were tested in the lab network, the IPv6 functionality was verified by testing different services over the network. The tests showed that it was possible to implement IPv6 after a step by step model. The result of this work can be used to initiate and follow through with a transition to IPv6 since the user have a method to follow, recommendations to what needs to be done and proposed solutions that can be implemented after instructions.

In this exploratory study of 95 counseling program master's students at a large southwestern public university, students' scores on an admissions Group Interview Sociometric Rating did not correlate with their GRE Analytic Writing (GRE-AW) scores nor their basic skills course instructors' end-of-course assessment of students' counseling-related personality traits (Personality) or mastery of basic counseling skills (Mastery). However, Mastery was predicted by both Personality, with a large effect size, and GRE-AW, with a medium effect size. This study provides promising preliminary evidence that counselor educators may use Counselor Personality Assessment Ratings and GRE-AW scores to screen master's applicants by predicting students' abilities to master basic counseling skills early in their counselor preparation. Limitations of the study and recommendations for future research are discussed.

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Virtualization is the key technology that has provided the Cloud computing platforms a new way for small and large enterprises to host their applications by renting the available resources. Live VM migration allows a Virtual Machine to be transferred form one host to another while the Virtual Machine is active and running. The main challenge in Live migration over WAN is maintaining the network connectivity during and after the migration. We have carried out live VM migration over the WAN migrating different sizes of VM memory states and presented our solutions based on Open vSwitch/VXLAN and Cisco GRE approaches. VXLAN provides the mobility support needed to maintain the network connectivity between the client and the Virtual machine. We have setup an experimental testbed to calculate the concerned performance metrics and analyzed the performance of live migration in VXLAN and GRE network. Our experimental results present that the network connectivity was maintained throughout the migration process with negligible signaling overhead and minimal downtime. The downtime variation experience with change in the applied network delay was relatively higher when compared to variation experienced when migrating different VM memory states. The total migration time experienced showed a strong relationship with size of the migrating VM memory state. / 0763472814

The purpose of the study was to determine the degree of relationships among GRE scores, undergraduate GPA (UGPA), and success in graduate school, as measured by first year graduate GPA (FGPA), cumulative graduate GPA, and degree attainment status. A second aim of the study was to determine whether the relationships between the composite predictor (GRE scores and UGPA) and the three success measures differed by race/ethnicity and sex. A total of 7,367 graduate student records (masters, 5,990; doctoral: 1,377) from 2000 to 2010 were used to evaluate the relationships among GRE scores, UGPA and the three success measures. Pearson’s correlation, multiple linear and logistic regression, and hierarchical multiple linear and logistic regression analyses were performed to answer the research questions. The results of the correlational analyses differed by degree level. For master’s students, the ETS proposed prediction that GRE scores are valid predictors of first year graduate GPA was supported by the findings from the present study; however, for doctoral students, the proposed prediction was only partially supported. Regression and correlational analyses indicated that UGPA was the variable that consistently predicted all three success measures for both degree levels. The hierarchical multiple linear and logistic regression analyses indicated that at master’s degree level, White students with higher GRE Quantitative Reasoning Test scores were more likely to attain a degree than Asian Americans, while International students with higher UGPA were more likely to attain a degree than White students. The relationships between the three predictors and the three success measures were not significantly different between men and women for either degree level. Findings have implications both for practice and research. They will provide graduate school administrators with institution-specific validity data for UGPA and the GRE scores, which can be referenced in making admission decisions, while they will provide empirical and professionally defensible evidence to support the current practice of using UGPA and GRE scores for admission considerations. In addition, new evidence relating to differential predictions will be useful as a resource reference for future GRE validation researchers.

Accurately predicting the success of graduate students is an important aspect of determining which students should be admitted into graduate programs. The GRE is a pivotal factor to examine since it is one of the most widely used criteria for graduate school admission. Even though the GRE is advertised as an accurate tool for predicting first year graduate GPA, there is a lack of research on long term success factors such as time to degree and graduate rate (Luthy, 1996; Powers, 2004). Furthermore, since most studies have low minority sample sizes, the validity of the GRE may not be the same across all groups (ETS, 2008b; Kuncel, Hezlett, & Ones, 2001). Another gap in GRE studies is that few researchers analyze student characteristics, which may alter or moderate the prediction validity of the GRE. Thus, student characteristics such as degree of academic involvement, mentorship interactions, and other academic and social experiences have not been widely examined in this context. These gaps in the analysis of GRE validity are especially relevant given the high attrition rates within of some graduate programs (e.g., an estimated 68% of doctoral student never complete their programs in urban universities; Lovitts, 2001). A sequential mixed methods design was used to answer the research questions in two phases. The quantitative phase used student data files to analyze the relationship of two success variables (graduation rate and graduate GPA) to the GRE scores as well as other academic and demographic graduate student characteristics. The qualitative phase served to complement the first phase by describing a wider range of characteristics from the 11 graduate students who were interviewed. Both proximal and distal moderators influence student behaviors and success in graduate school. In the first phase of the study, the GRE was the distal facilitator under analysis. Findings suggested that both the GRE Quantitative and the GRE Verbal were predictors of success for master’s students, but the GRE Quantitative was not predictive of success for doctoral students. Other student characteristics such as demographic variables and disciplinary area were also predictors of success for the population of students studied. In the second phase of the study, it was inconclusive whether the GRE was predictive of graduate student success; though it did influence access to graduate programs. Furthermore, proximal moderators such as student involvement, faculty/peer interactions, motivational factors, and program structure were perceived to be facilitators and/or detractors for success.

Bacteria have the ability to sense different environmental signals. When an environmental stress is detected, bacteria rapidly adjust their gene expression profile to be able to survive and thrive. The transduction of such environmental signals often requires the coordinated involvement of several factors that constitute complex regulatory networks. Hence, depending on the combination of signals, a unique gene expression profile required to adapt to the specific stress conditions is generated. Proteins are the best-known regulatory factors. However, non-proteinaceous molecules are also important in signal-responsive control of bacterial gene expression. Alarmones are low molecular weight non-proteinaceous regulatory factors which can characteristically be rapidly turned-over to mediate instant changes in gene expression. One such alarmone is the modified nucleotide ppGpp, which directly binds to RNA polymerase to alter its activity. The levels of this alarmone are expected to rapidly increase in response to any environmental stress that result in slow proliferation. DksA, a putative ppGpp co-regulator that likewise directly targets RNA polymerase, has been suggested to be required for both the positive and negative regulation mediated by ppGpp in Escherichia coli. This thesis describes dissection of the role of ppGpp and DksA on transcriptional regulation, primarily using the fim genetic determinant that encodes for the type 1 fimbriae. Type 1 fimbriae are involved in adhesion to abiotic surface and initial adhesion/invasion of bladder cells, as well as in biofilm formation. We found that ppGpp regulates phase variation by increasing the sub-population of cells that express the fimbriae. The effect of ppGpp was ultimately traced to its role in transcription of the fimB gene that encodes a recombinase involved in the phase variation process (paper 1). In contrast, we unexpectedly found that lack of DksA causes an increase, rather than a decrease, in transcription from the fimB P2 promoter in vivo. However, in vitro transcription studies demonstrated that ppGpp and DksA, both independently and co-dependently, stimulate transcription from the fimB P2 promoter. These seemingly contradictory results from the in vivo and in vitro transcriptional studies were shown to be, at least in part, a consequence of the increased association of Gre-factors with RNA polymerase that can occur in the absence of DksA in vivo (paper 2). The results outlined above have implications for the role of ppGpp and/or DksA in global gene expression. Using gene expression profile (microarray analysis) during the transition from logarithmic to stationary phase of E. coli, we found that while most of the genes regulated by ppGpp and DksA are regulated in the same direction by the two factors, many were not. In addition to the fim genes, genes involved in flagella functioning, taxis responses, and a few genes encoding different transport systems are also differentially regulated in ppGpp- and DksA-deficient strains in vivo. Our results clearly indicate that the effect of deficiencies in ppGpp and DksA is far more complex than phenotypic similarity of the corresponding mutants anticipated by the proposed concerted action of ppGpp and DksA on gene expression (paper 2 & 3).

The global re-emergence of TB and other mycobacterial infections have underscored the need for a thorough investigation of the biology of the causative agent, Mycobacterium tuberculosis, at the molecular level. The peculiar features of the bacterium such as slow growth rate, dormancy, unique cell wall composition and resistance towards phagocytosis by macrophages demands a detailed understanding of different essential molecular processes including transcription in this genus. Sequencing of several mycobacterial genomes provided an impetus for understanding the gene function and regulation of this formidable pathogen. Transcriptional regulation is one of the major mechanisms controlling gene expression. While a number of transcription units, promoters, sigma factors, and gene functions were identified and characterized, key features of transcription process are yet to be understood. The current study aims to understand some of the facets of transcription initiation and elongation in mycobacteria. The thesis is divided into five chapters. Chapter 1 introduces the bacterial transcription process. It starts with the description of the central molecule in transcription -the RNA polymerase (RNAP) and its catalytic mechanism. In the next section, each step of the transcription initiation, elongation and termination has been discussed. The mechanistic details as well as the different cellular factors involved in the regulation of the transcription have been discussed. The final part gives an overview of the transcription machinery of the mycobacteria, describing the promoter specificity and regulation of different sigma factors and other transcription factors known till date in mycobacteria. The scope and the objectives of the thesis are presented at the end of this chapter. In Chapter 2, a method of purification of RNAP from mycobacteria for optimized promoter -polymerase interactions is described. In vitro transcription analysis is important to understand the mechanism of transcription. Various assays for the analysis of initiation, elongation and termination form the basis for better understanding of the process. Purified RNAP with high specific activity is necessary to carry out a variety of these specific reactions. The RNAP purified from Mycobacterium smegmatis from exponential phase showed low σA-promoter specificity in promoter -polymerase interaction studies. This is due to the presence of a large number of sigma factors during exponential phase and under-representation of σA required for house - keeping transcription. In vivo reconstitution of RNAP holoenzyme with σA and its purification procedure which resulted in a holoenzyme with stoichiometric σA content is described in this chapter. The reconstituted holoenzyme showed enhanced promoter -specific binding and transcription activity compared to the enzyme isolated using standard procedure. Chapter 3 is aimed at the comparison of promoter - specific events during transcription initiation in mycobacteria. DNA -protein interactions that occur during transcription initiation play an important role in regulating gene expression. To initiate transcription, RNAP binds to promoters in a sequence -specific fashion. This is followed by a series of steps governed by the equilibrium binding and kinetic rate constants, which in turn determine the overall efficiency of the transcription process. The first detailed kinetic analysis of promoter - RNAP interactions during transcription initiation in the σA-dependent promoters PrrnAPCL1, PrrnB and Pgyr of M. smegmatis are presented in this chapter. The promoters show comparable equilibrium binding affinity but differ significantly in open complex formation, kinetics of isomerization and promoter clearance. Furthermore, the two rrn promoters exhibit varied kinetic properties during transcription initiation and appear to be subjected to different modes of regulation. In addition to the distinct kinetic patterns, each one of the house -keeping promoters studied has its own rate-limiting step in the initiation pathway, indicating the differences in their regulation. Moving the focus of the thesis from transcription initiation to elongation, a transcript cleavage factor of M. tuberculosis has been characterized in Chapter 4. After initiation of transcription, a number of proteins participate during elongation and termination by modifying the properties of the RNAP. Gre proteins are one such class of transcription elongation factors which are conserved across bacteria. They regulate transcription by binding near the secondary channel of RNAP, projecting their N-terminal coiled-coil domain into the active center and stimulating hydrolysis of the newly synthesized RNA by RNAP in the backtracked elongation complexes. Rv1080c is a putative gre factor homolog (MtbGre) present in M. tuberculosis.The protein enhanced the efficiency of promoter clearance by lowering the abortive transcription and also rescued the arrested and paused elongation complexes efficiently in the GC rich mycobacterial template. The Gre factor of M. smegmatis encoded by the gene MSMEG_5263 also showed biochemical properties similar to the M. tuberculosis protein. Although the mycobacterial Gre is similar in domain organization and shared the key residues for catalysis and RNAP interaction with Escherichia coli Gre proteins, it could not complement the E. coli strain deficient in Gre factors. Moreover, MtbGre failed to rescue E. coli RNAP stalled elongation complexes, indicating the importance of specific protein - protein interactions for transcript cleavage. Decrease in the level of MtbGre also reduced the bacterial survival by several fold indicating its essential role in mycobacteria and suggesting that a single Gre copes up with the burden of transcription fidelity of the genome. Chapter 5 describes the studies carried out to identify Gre factor homologs in mycobacteria and deciphering their function during transcription. Gre factors are members of a growing family of proteins which regulate RNAP through secondary channel. Apart from the Gre factor, putative members of this class of proteins are identified in both M. smegmatis and M. tuberculosis.The closest homologue of the canonical Gre factor of M. tuberculosis in its genome is Rv3788. The protein has Gre factor like domain organization and possess the key acidic residues required for transcript cleavage activity and the putative hydrophobic RNAP interacting residues in the C-terminus similar to MtbGre. Despite having these common features, Rv3788 did not stimulate transcript cleavage. In contrast, it turns out to be a transcription inhibitor by preventing the binding of NTPs to the enzyme. The transcription inhibition is not promoter specific, and is mediated by its binding to RNAP through the secondary channel with its N-terminus coiled coil domain. Like M. tuberculosis, the fast growing non-pathogenic mycobacteria M. smegmatis also has an ORF (MSMEG_6292) which is homologous to its canonical Gre factor and it interacts with RNAP in a similar manner. However, this protein did not exert any transcript cleavage or inhibitory activities but could compete with the Gre factor for binding to RNAP. The Gre factor homologs in mycobacteria may be involved in regulation by inhibiting transcription or by blocking the RNAP secondary channel from other RNAP active site modulators.