Compressed sensing (CS) theory has demonstrated that sparse signals can be reconstructed from far fewer measurements than suggested by the Nyquist sampling theory. CS has received great attention recently as an alternative to the current paradigm of sampling followed by compression. Initial CS operated under the implicit assumption that the sparsity domain coefficients are independently distributed. Recent results, however, show that exploiting statistical dependencies in sparse signals improves the recovery performance of CS. This dissertation proposes model-based CS reconstruction techniques. Statistical dependency models for several CS problems are proposed and incorporated into different CS algorithms. These models allow incorporation of a priori information into the CS reconstruction problems. Firstly, we propose the use of a Bayes least squares-Gaussian scale mixtures (BLS-GSM) model for CS recovery of natural images. The BLS-GSM model is able to exploit dependencies inherent in wavelet coefficients. This model is incorporated into several recent CS algorithms. The resulting methods significantly reduce reconstruction errors and/or the number of measurements required to obtain a desired reconstruction quality, when compared to state-of-the-art model-based CS methods in the literature. The model-based CS reconstruction techniques are then extended to video. In addition to spatial dependencies, video sequences exhibit significant temporal dependencies as well. In this dissertation, a model for jointly exploiting spatial and temporal dependencies in video CS is also proposed. The proposed method enforces structural self-similarity of image blocks within each frame as well as across neighboring frames. By sparsely representing collections of similar blocks, dominant image structures are retained while noise and incoherent undersampling artifacts are eliminated. A new video CS algorithm which incorporates this model is then proposed. The proposed algorithm iterates between enforcement of the self-similarity model and consistency with measurements. By enforcing measurement consistency in residual domain, sparsity is increased and CS reconstruction performance is enhanced. The proposed approach exhibits superior subjective image quality and significantly improves peak-signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM).Finally, a model-based CS framework is proposed for super resolution (SR) reconstruction. The SR reconstruction is formulated as a CS problem and a self-similarity model is incorporated into the reconstruction. The proposed model enforces similarity of collections of blocks through shrinkage of their transform-domain coefficients. A sharpening operation is performed in transform domain to emphasize edge recovery. The proposed method is compared with state-of-the-art SR techniques and provides high-quality SR images, both quantitatively and subjectively.

Purpose: This study aims to (1) describe and analyse the local ground operator’s role in the network of the Botswana tourism industry, (2) to investigate what factors characterize and influence their relationships with foreign tour operators, as well as (3) to provide implications for improving these relations. Methodology: This study has been conducted as a case study, where the empirical data was collected during a two months field trip to Botswana. A qualitative research method, and a deductive approach has been used. Five semi-structured interviews were conducted with ground operators to get their perspective of their own situation, and one with a person representing a governmental organisation. Most data was collected through the interviews, but participating observation also served as a source of information. The validity and reliability of the study has been enhanced by defining core concepts, interviewing several respondents, using an interview guide and recording most of the interviews. Results: Local ground operators play are crucial role in the network of Botswana’s tourism industry, as they are engaged in a high number of business relationships, are bringing the services at the destination together, and are connecting them to the tourists. They play a role as both customers and suppliers. Their relationship to tour operators abroad consists of a lot of resource ties, activity links as well as some actor bonds. Trust is found to be a very essential part of the relationship, and they perceive themselves as being dependent on the tour operators. Culture is not identified as a major influencing factor. As for managerial recommendations, a better communication in expectations and an increased adaptation of products and processes, to create customer dependence, are among the results advised.

This research is aimed at assessing SADCC in relation to the degree to which it has accomplished its own aims, regional economic integration and reduction of dependency. The study has relied on and used the dependency theory which holds that the development in a peripheral capitalist system is a continuous process of dispossessing the less developed countries of their raw materials in favor of maintaining the advancement of the capitalist countries. In short, neo-colonial dependence view of underdevelopment attributes a large part of the Third World's continuing and worsening poverty to the existence and policies of the industrial capitalist and socialist countries and their extensions in the form of small but powerful elite groups in the less developed countries. The research came with the following findings and conclusions. That SADCC countries have been integrated into the capitalist system due to the European colonization. That despite the efforts of SADCC and their proclaimed goals of economic integration and self-reliance, the SADCC region has not reduced dependency but rather there is a new dependency on other external countries. SADCC's committed strategies have not produced self-reliance and economic integration in the region due to the structure and activities of SADCC. In order to correct this imbalance and dependency, few options are possible. SADCC should embark upon the socialist mode of development because socialist methods will diminish the degree of dependency as in the case of Cuba. Intra-regional trade should be encouraged to bring about some form of transaction flows and economic integration. Establish appropriate ways of encouraging agricultural productivity in order to alleviate the shortage of food problems in the region and adopt capital accumulation methods.

Dependency is defined as authentic or pathological and is seen as a component important to the treatment of patients with chronic illness. It is hypothesized that a significant portion of ecology patients will meet the criteria for pathological dependence and differ on psychological and physiological parameters from those who do not. This study strongly supports the first two hypotheses but does not find that the two groups differ physiologically. One hundred eleven variables are surveyed. Fifty-two show significant differences between the groups and 29 are significant at greater than the .0001 level. A discriminant analysis was used to determine the least number of orthogonal variables that best discriminate between the groups. These are MMPI Scales 8, 3, subscale Ma2, employment status, and early childhood illness.

R, a software package for statistical computing and graphics, has evolved into the lingua franca of (computational) statistics. One of the cornerstones of R's success is the decentralized and modularized way of creating software using a multi-tiered development model: The R Development Core Team provides the "base system", which delivers basic statistical functionality, and many other developers contribute code in the form of extensions in a standardized format via so-called packages. In order to be accessible by a broader audience, packages are made available via standardized source code repositories. To support such a loosely coupled development model, repositories should be able to verify that the provided packages meet certain formal quality criteria and "work": both relative to the development of the base R system as well as with other packages (interoperability). However, established quality assurance systems and collaborative infrastructures typically face several challenges, some of which we will discuss in this paper. / Series: Research Report Series / Department of Statistics and Mathematics

MSc (Med), Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand / Three separate recent publications used genome-wide RNA interference (RNAi) to screen for novel host factors that are required for HIV-1 infection and replication. This was achieved using small interfering RNAs (siRNAs) to silence the expression of ~21 000 human genes and determining the effect of each gene’s loss of function on HIV-1 replication. Collectively, several hundred genes have now been implicated as novel HIV-1 host factors (termed HIV-1 Dependency Factors, HDFs). However, differences in study design resulted in little overlap and limited interpretive value from the three published datasets. To identify novel HDFs that are potential targets for anti-HIV therapy, five putative HDFs (SPTBN1, TMED2, KIAA1012, PRDM14 and SP110) were chosen for validation. RNAi effecters (both siRNAs and expressed short hairpin RNAs) were used to silence the selected genes. Gene suppression was measured by quantitative RT-PCR assay and two candidate genes were studied further (SPTBN1 and SP110) based on efficient mRNA inhibition (over 90%). As efforts to deliver the RNAi effecters to a T-cell line were unsuccessful, the effect of this knockdown on HIV-1 replication (both early- and late-stage) was assessed in cultured TZM-bl cells, a HeLa-derived cell line that expresses HIV-1 entry receptors and an integrated luciferase reporter for HIV-1 transcriptional activity (also used in the first genome-wide RNAi screen). An initial viral challenge assay with Subtype C-enveloped pseudovirus showed a 60% decrease in TZM-bl luciferase reporter activity in cells with suppressed SPTBN1 function, while knockdown of SP110 showed no effect on reporter activity. The final experiment, using fully-replicating Subtype B virus, showed a 75% decrease in late-stage viral replication when SPTBN1 expression was suppressed. In addition, SP110 suppression was confirmed to have no effect on TZM-bl reporter activity during any stage of HIV-1 replication. In conclusion, SPTBN1, but not SP110, is required for late-stage HIV-1 replication, though these results need to be confirmed in CD4+ T-cells. The absence of several important viral accessory factors from vi the virus used in the genome-wide screen may explain these findings and emphasises the need for using physiologically representative viral and cellular models to study the viral/cellular interactome.

Thesis advisor: Richard, S.J. McGowan / The Natural Resource Curse literature proposes to explain why and to what extent resource-wealthy countries have poor economic growth outcomes. Most research focuses on direct economic explanations, considering the role of governing institutions exogenously if at all. One emerging branch of explanations attempts to address this shortcoming, focusing on the indirect effects of institutional deterioration on economic outcomes in resource-rich countries. I add to this emerging literature by performing an econometric analysis of 16 oil-producing nations, examining the impact of national oil rent dependency on 12 dimensions of government quality from 1987-2008. I find that oil dependency has a significant negative impact on government quality in 11 of the 12 dimensions. I also find that controlling for preexisting levels of democracy does not significantly mitigate institutional resource curse effects. This runs counter to findings about economic effects, which tend to disappear when democracy levels are high. / Thesis (BA) — Boston College, 2010. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Economics Honors Program. / Discipline: College Honors Program. / Discipline: Economics.

Este trabalho busca contribuir para o debate a respeito do desenvolvimento econômico no Brasil, em particular para a busca de explicações a respeito do crescimento baixo e instável apresentado pela economia brasileira desde a década de 90. Ao contrário das interpretações ?endogenistas?, em nossa interpretação é central a condição periférica e dependente da economia brasileira na economia mundial. Partimos da noção de que estamos diante de uma nova fase do capitalismo, caracterizada por um regime de acumulação com dominância financeira, tal como já apontado por outros autores, defendendo-a contra as críticas mais recentes que recebeu, no interior do marxismo: a crítica baseada na teoria das ondas longas do capitalismo, segundo a qual não há nenhuma novidade na atual expansão financeira, e outra baseada na idéia de que, com a pós-grande indústria, o próprio capital produtivo é que teria um caráter rentista, o que levaria à ilusão de estarmos diante de uma dominância financeira. Entretanto, buscamos mostrar que a noção de dominância financeira desenvolvida por Chesnais e outros não trata das relações centro-periferia com profundidade e, por outro lado, as teorias que trataram das relações centro-periferia e da noção de dependência não construíram uma análise adequada a respeito das mudanças do capitalismo desde a década de 70, em particular do regime de acumulação. Por isso, procuramos unir estas duas leituras, para investigar como as relações de dependência dos países periféricos mudaram em função da mudança do regime de acumulação em escala mundial. Nosso foco está numa particular versão da teoria da dependência, que postulava a possibilidade de um desenvolvimento capitalista da periferia, ainda que dependente-associado, e que chega ao poder no Brasil na década de 90. Argumenta-se que o ?ângulo cego? desta teoria, que é a não percepção da mudança do regime de acumulação do capitalismo, trouxe um otimismo infundado sobre os benefícios de uma inserção (feita apressadamente e sem cuidado) no mercado financeiro internacional que aumentou a vulnerabilidade externa da economia brasileira, conduzindo a uma armadilha que impede o desenvolvimento econômico. / This work try to contribute for the debate regarding the economic development in Brazil, in particular for the search of explanations regarding the low and unstable growth presented by the Brazilian economy since the decade of 90. In contrast with the interpretations that emphasize internal factors, in our interpretation the peripheral and dependent condition of the Brazilian economy in the world-wide economy is central. We leave from the notion that we are facing a new phase of capitalism, characterized by a regimen of accumulation with financial domination, such as already pointed by other authors. We defend this vision against the two most recent critics that it has received, within the Marxist view: the first based in the theory of the long waves of capitalism, according to which there is no news in the current financial expansion, and the second based on the idea of that, with the post-great industry, the productive capital assumes a rentist character, that leads to the illusion that there is a financial domination. However, we try to show that the notion of financial domination developed by Chesnais and other authors does not deal adequately with the center-periphery relations. On the other hand, the theories that look for the center-periphery and dependence relations have not taken into account the changes of capitalism since the decade of 70, in particular the change in the regimen of accumulation. Therefore, we try to join these two visions, to investigate how the dependence relations of the peripheral countries have moved together with the change in the regimen of accumulation in a world-wide scale. Our focus is in a particular version of dependence theory, that claimed the possibility of a capitalist development of the periphery, called dependent-associate development. This work argues that the limits of this theory, that is the unperception of the change in the regimen of accumulation of capitalism, led to a baseless optimism on the benefits of a brazilian insertion in the international financial market, which led to a trap that hinders the economic development.

by Wing-hung Tang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 152-169.

Pancreatic ductal adenocarcinomas (PDACs) are highly aggressive malignancies, associated with poor clinical prognosis and limited therapeutic options. The KRAS oncogene is mutated in over 90% of PDACs and plays a pivotal role in tumor progression. Global gene expression profiling of PDAC reveals 3-4 major molecular subtypes with distinct phenotypic traits and pharmacological vulnerabilities, including variations in oncogenic KRAS pathway dependencies. PDAC cell lines of the aberrantly differentiated endocrine exocrine (ADEX) subtype are robustly KRAS-dependent for survival. The KRAS gene is located on chromosome 12p11-12p12, a region amplified in 5-10% of primary PDACs. Within this amplicon, we identified co-amplification of KRAS with the STK38L gene in a subset of primary human PDACs and PDAC cell lines. This provided rationale to determine whether PDAC cell lines are dependent on STK38L expression for proliferation and viability. STK38L (also known as NDR2) encodes a nuclear Dbf2-related (NDR) serine/threonine kinase, which shares homology with Hippo pathway LATS1/2 kinases. We show that STK38L expression levels are elevated in a subset of primary PDACs and PDAC cell lines that display ADEX subtype characteristics, including overexpression of mutant KRAS. RNAi-mediated depletion of STK38L in a subset of ADEX subtype cell lines results in decreased cellular proliferation and increased apoptotic cell death. Concomitant with cytostatic and cytotoxic effects, STK38L depletion causes increased expression of the LATS2 kinase and the cell cycle regulator p21. LATS2 depletion partially rescues the cell proliferation and viability effects of STK38L depletion. Lastly, high STK38L mRNA expression is associated with worse patient prognosis compared to low STK38L expression in PDACs. Taken together, our study uncovers STK38L as a candidate, targetable vulnerability in a subset of molecularly defined PDACs. / 2019-11-01T00:00:00Z