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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.
61

Ideologický základ hnutí FARC a jeho proměna / The Ideological Basis of the FARC Movement and its Transformation

Falc, Martin January 2013 (has links)
(in English): This work studies the genesis of the FARC's ideological nature and the consequences of changes in its development which have had an impact on the conduct of warfare. A number of aspects which, in varying degrees, affect the direction of the guerrilla group are analysed successively. Firstly, the roots of the movement are discussed along with events which led to the creation of the FARC and the legitimacy of its political program. Thereafter, the functionality of the security policy of Colombian presidents for the last thirty years is examined. Participation in the illegal drug trade, which constantly changes the guerrilla's mechanism of functioning, has had appreciable influence on the process of forming the movement and consequently on the public view of the organization. Based on the study of the stated aspects and the analysis of three key constituents of guerrilla movement - political, military and economic components - a scheme describing the hierarchic realignment that has resulted in the consequent transformation of the organization was created.
62

Personalized Cognitive Counseling Reduces Drinking Expectancy Among Men Who Have Sex with Men and Transgender Women in Lima, Peru: A Pilot Randomized Controlled Trial

Passaro, R. Colby, Chávez-Gomez, Susan, Castañeda-Huaripata, Angelica, Gonzales-Saavedra, Williams, Beymer, Matthew R., Segura, Eddy R., Nanclares, Francisco, Dilley, James, Cabello, Robinson, Clark, Jesse L. 01 November 2020 (has links)
Personalized cognitive counseling (PCC) is an evidence-based intervention designed to modify HIV-related risk behavior. We assessed the impact of PCC on sexual behavior, drinking expectancy, and incidence of sexually transmitted infections (STIs) in a 6-month randomized controlled trial among 153 HIV-uninfected men who have sex with men (MSM) and transgender women (TW) in Peru. Study retention was ≥ 90%, with three HIV infections (3 Control) and 19 cases of GC/CT (10 Control, 9 PCC) at 6 months. There was a decline in condomless receptive anal intercourse in the Control (0.74, 95% CI 0.60-0.91; p < 0.01) and PCC arms (0.72, 0.55-0.94; p = 0.02) at 6-month follow-up. There was a decrease in drinking expectancy at 6 months among participants endorsing alcohol use in the PCC arm (0.89, 0.83-0.96; p < 0.01), versus no change in the Control arm (0.98, 0.92-1.04; p = 0.54). PCC was efficacious in reducing drinking expectancy and HIV risk among MSM and TW in Peru. / National Institutes of Health / Revisión por pares
63

Figures of Merit for Photocatalysis: Comparison of NiO/La-NaTaO3 and Synechocystis sp. PCC 6803 as a Semiconductor and a Bio-Photocatalyst for Water Splitting

Welter, Eike S., Kött, Sebastian, Brandenburg, Fabian, Krömer, Jens, Goepel, Michael, Schmid, Andreas, Gläser, Roger 03 May 2023 (has links)
While photocatalysis is considered a promising sustainable technology in the field of heterogeneous catalysis as well as biocatalysis, figures of merit (FOM) for comparing catalytic performance, especially between disciplines, are not well established. Here, photocatalytic water splitting was conducted using a semiconductor (NiO/La-NaTaO3) and a bio-photocatalyst (Synechocystis sp. PCC 6803) in the same setup under similar reaction conditions, eliminating the often ill-defined influence of the setup on the FOMs obtained. Comparing the results enables the critical evaluation of existing FOMs and a quantitative comparison of both photocatalytic systems. A single FOM is insufficient to compare the photocatalysts, instead a combination of multiple FOMs (reaction rate, photocatalytic space time yield and a redefined apparent quantum yield) is superior for assessing a variety of photocatalytic systems.
64

The Cyanobacterial Uptake Hydrogenase : Regulation, Maturation and Function

Holmqvist, Marie January 2010 (has links)
With accellerating global warming and pollution problems a change of energy regime is necessary. Solar energy offers a clean and unlimited energy source of enormous potential. Due to it’s intermittenet nature solar energy must be stored - ideally in the chemical bond of a carrier molecule. Hydrogen gas, H2, an energy carrier with water as only emission when used in a fuel cell, is considered to be the choise for the future. In this context cyanobacteria show promising potential as future H2 factories since they can produce H2 from solar energy and water. The main enzymes directly involved in cyanobacterial hydrogen metabolism are nitrogenases and hydrogenases. Cyanobacterial hydrogenases are either uptake hydrogenases or bidirectional hydrogenases and their maturation requires assistance of six maturation proteins and two hydrogenase specific proteases. In this thesis the transcriptional regulation, maturation and function of the cyanobacterial uptake hydrogenases were investigated in the filamentous, heterocyst forming strains Nostoc punctiforme ATCC 29133 and Nostoc sp. strain PCC 7120. Five genes, encoding proteins putatively involved in the maturation of the uptake hydrogenase were identified upstream the known maturation genes. Two transcription factors, CalA and CalB, were found interacting with the stretch of DNA forming the upstream regions of the uptake hydrogenase structural genes and the novel maturation genes. The expression of the uptake hydrogenase were  heterocysts specific and the specificity mapped to a short promoter region starting -57 bp upstream the transcription start point. In addition, the function of the uptake hydrogenase was inserted in a metabolic context. Among the proteases, a conserved region was discovered possibly involved in determining the hydrogenase specificity. This thesis has given valuable information about the transcriptional regulation, maturation and function of the uptake hydrogenase in filamentous, heterocystous cyanobacteria and identified new targets for bioengineering of mutant strains with higher H2 production rates.
65

FTIR Difference Spectroscopy for the Study of P700, the Primary Electron Donor in Photosystem I

Wang, Ruili 12 January 2006 (has links)
This thesis describes an investigation of the molecular mechanism underlying solar conversion processes that occur in Type I photosynthetic reaction centers, in which P700 plays a central role. Static Fourier transform infrared (FTIR) difference spectroscopy (DS) was used to probe the electronic and structural organization of P700 and P700+. In combination with isotope labeling and site directed mutagenesis we have investigated how protein interactions such as histidine ligation and hydrogen bonding modulate this organization. Comparison of (P700+-P700) FTIR difference spectra (DS) obtained using wild type and mutant PS I led us to suggest that the 131 keto carbonyl group of PA is essentially free from hydrogen bonding in the ground state. Upon cation formation, this hydrogen bonding becomes stronger, probably because of a cation induced reorientation of the hydroxyl group of a nearby threonine residue. We also tentatively suggested that a difference band at 1639(-)/1660(+) cm-1 in (P700+-P700) FTIR DS might be due to a C=C mode of the imidazole side chain of the ligating histidine residues. Most of this thesis is geared towards investigating the validity of this interpretation. (P700+-P700) FTIR DS obtained using mutant PS I particles in which hydrogen bonding to P700 is altered can be reconciled within the context of our new interpretation. (P700+-P700) FTIR DS obtained using uniformly 2H, 15N, and 13C labeled PS I particles also support our new interpretation, and indicate that the difference band at 1639(-)/ 1660(+) cm-1 cannot be associated with a strongly hydrogen bonded keto carbonyl group of PA. To investigate if the imidazole side-chain of ligating histidine residues could contribute to bands in (P700+-P700) FTIR DS vibrational mode frequencies and intensities for several protonation forms of 4-methylimidazole were calculated. The calculations suggest that the 1639(-)/1660(+) cm-1 band in (P700+-P700) FTIR DS may not be due to a C=C mode of the imidazole side chain of the ligating histidine residues. Thus we have produced data that suggests neither of the proposed interpretations alone can adequately explain the origin of the 1639(-)/1660(+) cm-1 difference band in (P700+-P700) FTIR DS. The origin of the 1639(-)/1660(+) cm-1 difference band in (P700+-P700) FTIR DS is therefore still an open question.
66

Impact of Particle Morphology on the Rheology of PCC-Based Coatings

Michel-Sanchez, Enrique 18 May 2005 (has links)
The impact of particle size, size distribution, and particle shape on the rheology of precipitated calcium carbonate (PCC) based coatings was studied. Evaluating the interactions between different particle sizes and shapes leads to a better understanding of the packing fraction of PCC. HIgh packing fraction is desirable because of the positive impact on the fluidity of suspensions. Suspension with higher levels of fluidity can potentially load larger amounts of solids while keeping low viscosities. High solids suspensions are key factors to improve the efficiency of coating processes. To address this issue, PCC of different sizes and shapes where mixed in different ratiosto find mixtures with higher packing fractions that could result in coatings with lower viscosities. When coatings containing 90% of large particles and 10% by weight of small particles of different shape, viscosity decreases by 50% for one combination. The effect is caused by the higher packing fraction achieved. Future research is also described here.
67

Flicker Source Identification At A Point Of Common Coupling Of The Power System

Altintas, Erinc 01 June 2010 (has links) (PDF)
Voltage fluctuations under 30 Hz in the electricity grid, leads to oscillations in the light intensity that can be perceived by human eye, which is called flicker. In this thesis, the sources of the flicker at a point of common coupling is investigated. When there are more than one flicker sources connected to a PCC, individual effects of each flicker source is determined by using a new method which depends on the reactive current components of the sources. This method is mainly based on the flickermeter design defined by the International Electrotechnical Commission (IEC), but uses the current variations in addition to the voltage variations to compute flicker. The proposed method is applied to several different types of loads supplied from a PCC and their flicker contributions on the busbar are investigated. Experiments are performed on field data obtained by the power quality analyzers (PQ+) developed by the National Power Quality Project and the method has been found to provide accurate results for flicker contributions of various loads. The PQ+ analyzers with the proposed flicker contribution detection algorithm are called Flicker Contribution Meters (FCM) and they will be installed at the points of the Turkish Electricity Transmission Network when required.
68

Etude des mécanismes moléculaires et cellulaires responsables de la malignité des phéochromocytomes et des paragangliomes SDHB-dépendants

Loriot, Céline 30 June 2014 (has links) (PDF)
Les phéochromocytomes (PCC) et les paragangliomes (PGL) sont des tumeurs neuroendocrines rares, pour lesquelles le déterminisme génétique est très important, avec 16 gènes de prédisposition identifiés à ce jour. Au cours de ce travail de thèse, je me suis plus particulièrement intéressée aux conséquences des mutations du gène SDHB, car il avait été préalablement démontré qu'elles constituaient un facteur de risque de mauvais pronostic, associé à un phénotype métastatique et à une réduction de la survie des patients. Grâce à l'analyse du transcriptome d'une large cohorte de 188 échantillons de PCC/PGL humains, j'ai pu mettre en évidence que la voie de la transition épithélio-mésenchymateuse (EMT) était spécifiquement activée dans les tumeurs métastatiques SDHB-dépendantes. En effet, j'ai observé, dans ce sous-groupe de tumeurs, une surexpression de facteurs de transcription et de régulateurs précoces de l'EMT, comme TWIST1, TFC3, ou LOXL2 ; une perte d'expression de marqueurs de jonctions cellulaires, comme CDH2 et KRT19 ; ou encore une induction de gènes codant pour des enzymes pro-invasives, comme MMP1 et MMP2. Dans ces tumeurs, j'ai par ailleurs validé l'induction transcriptionnelle de l'EMT en mettant en évidence la rétention nucléaire de la protéine SNAIL (un facteur de transcription clé de l'EMT) sur des coupes de tissus. Dans cette même cohorte, l'analyse des données de méthylation globale de l'ADN nous a permis d'observer un phénotype hyperméthylateur dans les tumeurs SDHx, qui est expliqué par une inhibition de déméthylases de l'ADN et des histones par le succinate, qui s'accumule dans ces tumeurs où la succinate déshydrogénase est inactivée. Nous avons ainsi pu démontrer que le succinate est un oncométabolite qui induit des modifications épigénétiques impliquées dans l'extinction de nombreux gènes, et en particulier des gènes associés à l'EMT, comme le gène KRT19 (l'un des plus hyperméthylés dans les tumeurs SDHB-malignes, comparativement aux autres). J'ai ensuite caractérisé le premier modèle cellulaire de PCC/PGL porteur d'une inactivation complète du gène Sdhb, dans lequel j'ai confirmé l'activation de l'EMT, au niveau transcriptionnel et au niveau protéique. La caractérisation fonctionnelle de ces cellules m'a ensuite permis de mettre en évidence des propriétés migratoires, invasives, et adhésives spécifiques des cellules chromaffines Sdhb -/-. J'ai par la suite focalisé mon étude sur le gène Krt19, qui code pour une protéine du cytosquelette, la kératine 19 et qui est éteint dans les tumeurs et dans les cellules Sdhb -/-. La réintroduction de ce gène dans les cellules Sdhb -/- et son inhibition dans les cellules sauvages m'ont permis de conclure à l'implication de la kératine 19 dans les processus d'adhésion, de migration et d'invasion. Cependant je n'ai pas pu expliquer l'ensemble du phénotype par la seule modulation de ce gène, ce qui démontre l'implication d'autres acteurs dans la mise en place du phénotype invasif décrit. Mes travaux de thèse ont ainsi permis de démontrer que l'activation de l'EMT est responsable du caractère métastatique et invasif observé dans les tumeurs porteuses d'une mutation sur le gène SDHB et que cette activation est notamment secondaire aux modifications épigénétiques induites par l'inactivation de la succinate déshydrogénase.
69

“Enxugando iceberg” como as instituições estatais exercem o controle do crime em São Paulo

Silvestre, Giane 19 August 2016 (has links)
Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-01-11T11:06:18Z No. of bitstreams: 1 TeseGS.pdf: 6224657 bytes, checksum: 1ce36ae40d89c7d6fcd9526473d40e1e (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-13T18:53:59Z (GMT) No. of bitstreams: 1 TeseGS.pdf: 6224657 bytes, checksum: 1ce36ae40d89c7d6fcd9526473d40e1e (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-13T18:54:07Z (GMT) No. of bitstreams: 1 TeseGS.pdf: 6224657 bytes, checksum: 1ce36ae40d89c7d6fcd9526473d40e1e (MD5) / Made available in DSpace on 2017-01-13T18:54:16Z (GMT). No. of bitstreams: 1 TeseGS.pdf: 6224657 bytes, checksum: 1ce36ae40d89c7d6fcd9526473d40e1e (MD5) Previous issue date: 2016-08-19 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / This research aimed to understand how the institutions and state operators’ crime control are being affected by the emergence of new forms of organization of the "world of crime." It wondered how the institutions and operators find themselves affected by the emergence of the First Command of the Capital, the PCC; which the impact on their work, on the ways to exercise control and institutional management of the crime; which representations they elaborate about the changes in the contexts they operate and develop their professional activities. Therefore, it started analyzing two empirical cases that took place in São Paulo, involving the PCC and the so-­‐‑called "debate" -­‐‑ a new management mechanism of violence brought from the consolidation of the CPC in and out of the São Paulo prison system. The cases also help to identify two main strategies to crime control in São Paulo: i) a militarized control guided mainly by lethal and selective fighting with alleged criminals, played by the Military Police and; a classic judicial control, in which the logic of the investigation remains linked to archaic model of the police investigation and prioritizes incarceration for certain types of crimes and people, while holding the low levels of punishment for cases of police lethality. Part of the field work was conducted through interviews with civil and military police, sheriffs, prosecutors and judges who work in crime control, including the Special Group Against Organized Crime of the Prosecutor's Office (GAECO). It was developed a research based on official data on crime and on investments in public safety in order to observe trends, preferences and policy choices of area managers in the last decade. The results indicate that the emergence of the PCC has affected the crime control strategies performed by each of these institutions, although continuities have been observed. The PCC started seen as "organized crime", sign often claimed to justify violent and lethal actions in alleged confrontations. Investigations involving the PCC have been recurrently conducted through a partnership between prosecutors and military police, often rather of the judicial police, which has generated tensions between the institutions and their operators. The Civil Police, in its turn, operates with the coexistence of "inquisitorial logic" of investigation and effort to operates the transformations that the emergence of "organized crime" has imposed, besides seeking to circumvent the arising obstacles "scrapping" of institution. / O objetivo desta pesquisa foi compreender a forma como as instituições e os operadores estatais do controle do crime estão sendo afetados pela emergência das novas formas de organização do “mundo do crime”. Perguntou-se como as instituições e os operadores se veem afetados com a emergência do Primeiro Comando da Capital, o PCC; qual o impacto disto sobre o seu trabalho, sobre os modos de exercer o controle e a administração institucional do crime; quais representações eles elaboram sobre as mudanças nos contextos em que atuam e desenvolvem suas atividades profissionais. Para tanto, partiu-se da análise de dois casos empíricos ocorridos no interior de São Paulo, envolvendo o PCC e o chamado “debate” - um novo mecanismo de gestão da violência trazido com a consolidação do PCC dentro e fora do sistema prisional paulista. Os casos também auxiliaram na identificação de duas estratégias centrais no controle ao crime em São Paulo: i) um controle militarizado pautado, sobretudo, pelo enfrentamento letal e seletivo de supostos criminosos, rotagonizado pela Polícia Militar e; ii) um controle judicial clássico, no qual a lógica da investigação permanece vinculada ao modelo arcaico do inquérito policial e que prioriza o encarceramento para determinados tipos de crimes e sujeitos, ao mesmo tempo em que sustenta os baixos índices de punição para os casos de letalidade policial. Parte do trabalho de campo foi realizado por meio de entrevistas com policiais civis e militares, delegados, promotores e juízes que atuam no controle do crime, incluindo o Grupo de Atuação Especial Contra o Crime Organizado do Ministério Público (GAECO). Também foi elaborada uma pesquisa com base em dados oficiais sobre a criminalidade e sobre os investimentos em segurança pública, a fim observar as tendências, preferências e escolhas políticas dos gestores da área na última década. Os resultados indicam que a emergência do PCC tem afetado as estratégias de controle do crime executada por cada uma destas instituições, ainda que permanências tenham sido observadas. O PCC passou a carregar o signo de “crime organizado”, muitas vezes acionado para justificar ações violentas e letais em supostos confrontos. As investigações que envolvem o grupo têm sido recorrentemente, executada por meio de uma parceria entre Ministério Público e Polícia Militar, muitas vezes, em detrimento da polícia judiciária, o que tem gerado tensões entre as instituições e seus operadores. A polícia civil, por sua vez, convive com a coexistência entre a “lógica inquisitorial” da investigação e o esforço em operar as transformações que a emergência do “crime organizado” tem lhe imposto, além buscar driblar os obstáculos advindos do “sucateamento” da instituição.
70

Pingu och PSC: språkljudsproduktion hos barn med språkljudsstörning vid fyra olika taluppgifter : Analys av träffsäkerhet och avvikelsetyper samt utvärdering av en ny eliciteringsmetod och ett nytt träffsäkerhetsmått

Ode, Carina, Öster Cattu Alves, Mirjam January 2018 (has links)
ABSTRACT The purpose of the current study was to compare speech samples elicited with four different methods regarding speech sound production errors. Nine Swedish-speaking children with SSD (Speech Sound Disorder) participated. A new method of speech elicitation was introduced, a narrative task using a silent short film as a prompt. Severity of involvement of the speech sound production was measured using PCC-R (Percentage of Consonants Correct-Revised), as well as a new severity metric, PSC (Percentage of Syllables Correct). Speech error patterns were also analyzed. All four methods of speech elicitation are suggested to be useful clinical tools for phonological assessment. The elicitation methods yielded similar results. However, the results indicated that a higher degree of control and phonological complexity in a task generally yield lower severity measures and more types of speech error patterns. The definition of SSD used in this study includes several clinical diagnoses used by speech and language pathologists. The participants’ results were therefore analyzed regarding clinical diagnosis. No difference was found. This first evaluation of PSC shows that it is a promising new severity metric, and that its strength lies first and foremost in the possibility to include unintelligible speech. The evaluation of the new elicitation task shows that narration of a silent short film as a prompt is promising as well. The results yielded indicate a gain in degree of control combined with a preserved high ecological validity associated with speech elicitation methods yielding conversational speech. SAMMANFATTNING Syftet med den här studien var att undersöka variation av avvikelser i språkljudsproduktionen hos nio svensktalande barn med språkljudsstörning vid fyra olika taluppgifter. En av de fyra uppgifterna innefattade en ny eliciteringsstrategi: berättande till ljudlös film. Grad av avvikelse undersöktes genom beräkning av PCC-R (Percentage of Consonants Correct-Revised), samt ett nytt mått, PSC (Percentage of Syllables Correct). Även avvikelsetyper undersöktes. Resultatet tyder på att samtliga undersökta taluppgifter kan vara användbara kliniska verktyg. Även om ingen skillnad kunde påvisas mellan deltagarnas grad av avvikelse vid de fyra taluppgifterna, sågs en tendens till att en hög styrningsgrad och fonologisk komplexitet av målorden ger upphov till en lägre träffsäkerhet i språkljudsproduktionen och ökar antalet olika avvikelsetyper som förekommer. Definitionen av språkljudsstörning inkluderar olika logopediska diagnoser. I denna studie kunde barnens diagnostillhörighet inte förklara variationer i resultaten. Den första utvärderingen av PSC visar att det är ett lovande nytt mått på träffsäkerhet i språkljudsproduktionen, och att dess styrka framför allt ligger i möjligheten att inkludera oförståeligt tal. Även denna första utvärdering av den nya eliciteringsmetoden berättande till ljudlös film är lovande. Resultaten tyder på en högre styrningsgrad samtidigt som den ekologiska validiteten i sammanhängande tal till stor del bibehållits.

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