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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

CONDENSIN II CHROMOSOME INDIVIDUALIZATION IS NECESSARY FOR MEIOTIC SEGREGATION AND ANTAGONIZES INTERPHASE CHROMOSOME ALIGNMENT

Hartl, Tom A. January 2008 (has links)
Maintenance of an intact genome and proper regulation of the genes within are crucial aspects for life. The work of this dissertation has implicated the Drosophila condensin II complex in both processes. Condensin II's ability to reconfigure chromosomes into spatially separated and discrete units is necessary to ensure proper meiotic segregation. When this "individualization" activity fails in a condensin II mutant, chromosomes remain entangled, and either cosegregate or become lost during cell division. This leads to the creation of aneuploid sperm. We have also implicated condensin II as a factor necessary to individualize interphase somatic chromosomes from one another. This is relevant in Drosophila because the association of homologous chromosomes is thought to facilitate gene regulation activity in trans. We speculate that condensin II individualization spatially distances aligned chromosomes from one another and prevents this trans-communication between allelic loci. This is supported first by an increase of homologous chromosome pairing in a condensin II mutant background. Secondly, loss of condensin II leads to elevated production from alleles that are known to depend on pairing for transcriptional activation. These meiotic and interphase condensin II roles support its necessity to Drosophila genome integrity and transcriptional regulation. Given the conservation of condensin from bacteria to humans, it is likely that equivalent or related roles exist in a variety of species.
82

Digital signal processing extra-tropical cyclones warning system using WiMAX

Al-Breiki, Mohamed Ahmed Mohamed Naser January 2013 (has links)
This research project proposed a unique solution to make use of these base stations to keep all subscribers alerted with warning of possible disaster should that be required. As the current, network does not provide a provision for such a noble approach, a new network model has been developed and simulated to interface a sensor (weather station, WeS), with WiMAX weather station. The weather station is based on DSP processor to receive a digitised sensor values, process these values, analyse them and if they fall within the alert zones, packet them according to WiMAX protocol and send them to subscribers. The developed standard bypasses any commercial network to offer free transmission to subscribers. This setup is also able to extract information on weather condition or react on uncertainty, i.e. disaster scenarios. Natural disasters, such as torrent, tornado/ hurricane, volcano eruption, earthquake, Tsunamis or landslide are increasing. Unfortunately they bring with them human tragedies, environment catastrophes, villages, cities and counties are subject to endless devastation during and after the destructive forces. Water, electricity and gas supply are most disrupted and difficult to restore in short time. However, communication is another item that can be affected adversely but WLAN with specific considerations, should be excluded from the effect. This project presents a solution, albeit minor relative to the maximum effect of the disaster, but will keep the telecommunication/communication in operation. Our novel technique, a “Clone Wireless Wide Area Network (CloneWAN)” is a clone wireless network to the wired Network. In the event of natural calamities, it gives continuity of network operation. It is based on WiMAX. The realization of CloneWAN has been formed and simulated to set the national network of the UAE at its correct form. CloneWAN model has been simulated with Opnet platform. All results revealed that the model is complete. The interface to Alerting System is discussed. Results show that the dynamic behavior of the parameters delay and Throughput of CloneWAN model is stable over various and different load scenarios. WiMAX is a de-facto standard in the current and future network requirement standards. Its main component is the Base Station which is normally stationed in the air, high enough to couple signals from other base stations. It is purpose is merely focused on networking signals for commercial purposes. The suggested hardware interface for the Weather Station is based on DSP SHARC processor. The model has been written in C and simulated under Opnet package. A number of scenarios have been set to represent different disasters worldwide. All results are listed and discussed later in the thesis.
83

Svensk och Finsk jordbrukspolitik, en kalvdans i otakt : – en komparativ teoriprövande fallstudie baserad på historisk institutionalism gällande de jordbrukspolitiska målsättningarna mellan åren 1995-2015.

Petersson, Kristin January 2016 (has links)
This study aims at examine why the agricultural policy in Sweden and Finland has turned out different, despite the Common Agricultural Policy (CAP). The study is a compare case study where Sweden and Finland are used to draw general conclusions. The question asked to pursue the aim are; what kind of agricultural goals did Sweden and Finland negotiate for during the membership-process to the European Union (EU), what kind of agricultural goals did the both states negotiate for during the reform of CAP 2003 and 2015, are their differences in the national regulations that can explain the actual development and can the agricultural policy today be seen as a result from the goals during the membership-process? In this study an analytical model is created and used to analyze the aim, the model is based on the theory of historical institutionalism to describe the general development and it’s also applied in the empirical analysis. The empirical material consists of books, articles and primary document etc. One general conclusion asserts that the actual development in the agricultural policy can be traced back in the historic context. In Sweden’s case the process can be connected to the agricultural deregulation that took place before the membership. In Finland’s case the development can be associated with the overproduction during the 1960-1970 and its goals with a high level of self-sufficiency. Another conclusion affirms that the national regulation where Sweden and Finland has had the opportunity to shape their own regulations and structures is one of several explanations to the aim.
84

Theta liftings on higher covers of symplectic groups

Leslie, Spencer January 2018 (has links)
Thesis advisor: Solomon Friedberg / We study a new lifting of automorphic representations using the theta representation ϴ on the 4-fold cover of the symplectic group, $\overline{\Sp}_{2r}(\A)$. This lifting produces the first examples of CAP representations on higher degree metaplectic covering groups. Central to our analysis is the identification of the maximal nilpotent orbit associated to ϴ. We conjecture a natural extension of Arthur's parameterization of the discrete spectrum to $\overline{\Sp}_{2r}(\A)$. Assuming this, we compute the effect of our lift on Arthur parameters and show that the parameter of a representation in the image of the lift is non-tempered. We conclude by relating the lifting to the dimension equation of Ginzburg to predict the first non-trivial lift of a generic cuspidal representation of $\overline{\Sp}_{2r}(\A)$. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Mathematics.
85

S čepičkou nebo bez čepičky? Iniciace translace eukaryot se zaměřením na opurtunního patogena C. albicans / To cap or not to cap? Eukaryotic translation initiation with a special interest in human opportunistic pathogen C. albicans

Feketová, Zuzana January 2011 (has links)
Candida albicans belongs to serious human opportunistic pathogens, causing severe health complications to immunocompromised patients. To my best knowledge, it is the only organism that survives with unmethylated cap structures found on the 5'ends of mRNA molecules. Using functional assay, I demonstrated that orf19.7626 codes for C. albicans translation initiation factor 4E (Ca4E). We couldn't prove our hypothesis, that Ca4E could be responsible for the unmethylated cap recognition in our model organism S. cerevisiae. Candida sp. possesses also another rather unusual feature - ambiguous CUG codon. In most of the cases, CUG is decoded as a serine, but sometimes also as a leucine. This gives rise to a so called "statistical proteome". One CUG codon is also part of the mRNA coding for Ca4E protein, therefore two versions of Ca4E-Ca4ELeu and Ca4ESer -might occur in C. albicans simultaneously. Both of them are able to rescue deletion of S. cerevisiae eIF4E gene, but they confer temperature sensitivity to the heterologous host. This phenotype is more pronounced with the Ca4ELeu version. We observed milder temperature sensitive phenotype after co-expression of Ca4E together with C. albicans eIF4G (Ca4G). Conformational coupling between eIF4E and eIF4G leads to enhanced affinity of eIF4E to the cap...
86

Policies to Reduce CO2 Emissions: Fallacies and Evidence from the United States and California

Granados, José A. Tapia, Spash, Clive L. January 2019 (has links) (PDF)
Since the 1990s, advocates of policy to prevent catastrophic climate change have been divided over the appropriate economic instruments to curb CO2 emissions-carbon taxes or schemes of emission trading. Barack Obama claimed that policies implemented during his presidency set in motion irreversible trends toward a clean-energy economy, with the years 2008-2015 given as evidence of decoupling between CO2 emissions and economic growth. This is despite California being the only state in the USA that has implemented a specific policy to curb emissions, a cap-and-trade scheme in place since 2013. To assess Obama's claims and the effectiveness of policies to reduce CO2 emissions, we analyze national and state-level data from the USA over the period 1990-2015. We find: (a) annual changes in emissions strongly correlated with the growth conditions of the economy; (b) no evidence for decoupling; and (c) a trajectory of CO2 emissions in California which does not at all support the claim that the cap-and-trade system implemented there has reduced CO2 emissions. / Series: SRE - Discussion Papers
87

Economic Subterfuge and the NBA Lockout

Shah, Parin January 2012 (has links)
Thesis advisor: Richard, S.J. McGowan / At the very core of the National Basketball Association’s labor negotiations between the owners and the players during the 2011 lockout was the league’s argument that its economic structure was broken. Owners contended that the NBA’s soft salary cap system, and the resulting payroll disparity, has put small-market franchises at a talent disadvantage and produced a league of haves and have-nots. To remedy this purported competitive balance problem, the owners demanded severe policy measures to decrease the pay dispersion among teams. However, the players union cautioned that these hardline provisions were merely an attempt to transfer wealth from players to owners. This charge warranted further analysis. Existing literature on this topic is either outdated or insufficient in scope. As such, using regression analysis, this thesis evaluated the league’s argument and determined to what extent the league’s soft salary cap system has contributed to its competitive imbalance.The empirical analysis of this thesis produced several meaningful conclusions. While the NBA has relative imbalance, it does not affect consumer demand for the regular season product. Moreover, while pay dispersion exists, additional salary expenditures only marginally add to a team’s winning percentage. There is no significant relationship between payroll disparity and competitive balance. Finally, with the escalating importance of media rights contracts and the historical appreciation of franchise valuation, the league overstated the financial distress of most of its small-market owners. Overall, the NBA and its owners used deceptive rhetoric and misleading economic policies to decrease player salaries, not to increase competitive balance, in a collusive effort to maximize profits and reassert its diminishing monopsony power in an increasingly star-driven league. / Thesis (BS) — Boston College, 2012. / Submitted to: Boston College. Carroll School of Management. / Discipline: Carroll School of Management Honors Program. / Discipline: Economics.
88

Estudo das interações hiperfinas em nanopartículas de Fe3O4  e  Fe3O4  dopadas com gadolínio pela espectroscopia de correlação angular perturbada / Study of hyperfine interactions in nanoparticles of Fe3O4 and Gd-doped Fe3O4 by perturbed angular correlation spectroscopy

Huet, Sarah Damasceno Pinheiro 22 April 2014 (has links)
Neste trabalho foram estudadas as nanopartículas magnéticas (NPs) de interesse em biomedicina de Fe3O4 e de Fe3O4 dopadas com Gd 5% pela técnica de Espectroscopia de correlação angular gama-gama perturbada (CAP). As amostras de Fe3O4 foram sintetizadas pelos métodos de co-precipitação e decomposição térmica e as nanopartículas de Fe3O4 dopadas com Gd 5% foram sintetizadas pelo método da coprecipitação. As amostras de nanoparticulas foram caracterizadas quanto a sua estrutura pela difração de raios X (DRX) e quanto ao seu tamanho pela técnica de microscopia eletrônica de transmissão (TEM). Os resultados mostram que as nanoparticulas de ferrita mostram estrutura pertencente ao grupo espacial Fd3m e que seu tamanho é de 10 nm quando sintetizada por decomposição térmica e entre 7 e 15 nm quando sintetizada por co-precipitação. As nanopartículas de Fe3O4 sintetizadas pelo método de decomposição térmica apresentaram maior monodispersão do que as nanopartículas sintetizadas pelo método de co-precipitação, ou seja, o tamanho de grão estava mais homogêneo. A técnica CAP mostrou que a variação de tamanho das nanopartículas infuencia no comportamento magnético das mesmas e o dopante Gd atrapalha a introdução da sonda radioativa por competir pelos sítios de Fe. / In the work reported in this dissertation, magnetic nanoparticles of Fe3O4 and 5% Gddoped Fe3O4, which have applications in biomedicine, were studied by Perturbed Gamma-Gamma Angular correlation spectroscopy (PAC). Fe3O4 samples were synthesized by both, co-precipitation and thermal decomposition methods. Gd-doped Fe3O4 magnetic nanoparticles were synthesized only by co-precipitation method. Analysis of X-ray diffraction (XRD) showed that the samples belong to Fd3m space group. Transmission Electron Microscopy (TEM) showed that nanoparticles have sizes between 5 and 14 nm, suitable for biomedical applications. Fe3O4 nanoparticles synthesized by thermal decomposition method showed greater monodispersed nanoparticles than the samples synthesized by co-precipitation method. PAC technique using radioactive probe 111In (111Cd) showed that the size of the nanoparticles changes magnetic behavior and for the Gd-doped sample PAC measurements results showed that the introduction of radioactive probe is difficult due the presence of an impurity (Gd) and there is a competition for Fe sites between Gd and nuclear probe.
89

Estudo das interações hiperfinas em nanopartículas de Fe3O4  e  Fe3O4  dopadas com gadolínio pela espectroscopia de correlação angular perturbada / Study of hyperfine interactions in nanoparticles of Fe3O4 and Gd-doped Fe3O4 by perturbed angular correlation spectroscopy

Sarah Damasceno Pinheiro Huet 22 April 2014 (has links)
Neste trabalho foram estudadas as nanopartículas magnéticas (NPs) de interesse em biomedicina de Fe3O4 e de Fe3O4 dopadas com Gd 5% pela técnica de Espectroscopia de correlação angular gama-gama perturbada (CAP). As amostras de Fe3O4 foram sintetizadas pelos métodos de co-precipitação e decomposição térmica e as nanopartículas de Fe3O4 dopadas com Gd 5% foram sintetizadas pelo método da coprecipitação. As amostras de nanoparticulas foram caracterizadas quanto a sua estrutura pela difração de raios X (DRX) e quanto ao seu tamanho pela técnica de microscopia eletrônica de transmissão (TEM). Os resultados mostram que as nanoparticulas de ferrita mostram estrutura pertencente ao grupo espacial Fd3m e que seu tamanho é de 10 nm quando sintetizada por decomposição térmica e entre 7 e 15 nm quando sintetizada por co-precipitação. As nanopartículas de Fe3O4 sintetizadas pelo método de decomposição térmica apresentaram maior monodispersão do que as nanopartículas sintetizadas pelo método de co-precipitação, ou seja, o tamanho de grão estava mais homogêneo. A técnica CAP mostrou que a variação de tamanho das nanopartículas infuencia no comportamento magnético das mesmas e o dopante Gd atrapalha a introdução da sonda radioativa por competir pelos sítios de Fe. / In the work reported in this dissertation, magnetic nanoparticles of Fe3O4 and 5% Gddoped Fe3O4, which have applications in biomedicine, were studied by Perturbed Gamma-Gamma Angular correlation spectroscopy (PAC). Fe3O4 samples were synthesized by both, co-precipitation and thermal decomposition methods. Gd-doped Fe3O4 magnetic nanoparticles were synthesized only by co-precipitation method. Analysis of X-ray diffraction (XRD) showed that the samples belong to Fd3m space group. Transmission Electron Microscopy (TEM) showed that nanoparticles have sizes between 5 and 14 nm, suitable for biomedical applications. Fe3O4 nanoparticles synthesized by thermal decomposition method showed greater monodispersed nanoparticles than the samples synthesized by co-precipitation method. PAC technique using radioactive probe 111In (111Cd) showed that the size of the nanoparticles changes magnetic behavior and for the Gd-doped sample PAC measurements results showed that the introduction of radioactive probe is difficult due the presence of an impurity (Gd) and there is a competition for Fe sites between Gd and nuclear probe.
90

Modeling and Analysis of a Four-Switch Buck-Boost Dynamic Capacitor

Plasencia, Oscar 01 December 2011 (has links)
Modern electric power utilities are facing a variety of challenges introduced by the increasing complexity of their operation, structure, and consumer loads. One such challenge has been to supply the ever growing demand for reactive power which is essential for grid support. For this reason dynamic VAR technologies are becoming much more important to modern day power systems. A recent dynamic VAR technology known as the Dynamic Capacitor offers full quadrant capacitive VAR control through the combination of AC/AC buck and boost cells. This paper introduces a new topology deemed the “Four-Switch Buck-Boost Dynamic Capacitor” which promises to combine the performance of the AC/AC buck and boost cells into a single power electronic device. This is done in an effort to reduce the required component count and thus reduce the overall device footprint and implementation cost of the Dynamic Capacitor technology. Derivations and analysis will detail the workings of the Four-Switch Buck-Boost Dynamic Capacitor, while simulations in LTSpice and Matlab Simulink will demonstrate the functionality and performance of the proposed topology. The results of this thesis prove the Four-Switch Buck-Boost Dynamic Capacitor to be a feasible shunt reactive compensating device.

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