- 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.
Search results
Showing 21 to 29 of 29 (0.009 seconds)| 21 |
Biologia reprodutiva e presença de cromossomo B em Astyanax scabripinnis (Teleostei: Characidae)Cornelio, Diana 08 February 2013 (has links)
Made available in DSpace on 2017-07-21T19:59:59Z (GMT). No. of bitstreams: 1
Diana Cornelio.pdf: 3420425 bytes, checksum: ff1f9eef75ccbe98d2e754cd2215c5c5 (MD5)
Previous issue date: 2013-02-08 / Fundação de Amparo a Pesquisa do Estado de São Paulo / Astyanax scabripinnis is a species found in the neotropics, this species forms demes isolated populations in headwater streams. It is taxonomically unresolved, but is presented as an interesting model to study the presence of chromosomal B. The occurrence of these chromosomes in A. scabripinnis may be associated with various environmental factors and population, although little savvy about maintaining parasitic or possible heterotic effects of these chromosomes. The reproductive biology related to the presence of B chromosomes in A. scabripinnis never been addressed. Thus, the object of this study was to investigate whether aspects of the reproductive process, fundamental to the adaptive value may be related to the presence of B chromosomes in A. scabripinnis. Samples were collected quarterly between the years 2012 and 2013 in Campos do Jordao, Sao Paulo, Brazil (22 ° 40 '49.5 "S, 45 ° 23` 31.9 "W) at Stream Farm Lavrinha basin of the Paraíba do Sul. The gonads were classified macroscopically and microscopically second stages of development. Settled seasonally sex ratio of the population in the different samples. We calculated the gonadosomatic ratio (GSR) and the relationship hepatossomática (RHS) separately for females with and without chromosome B. The presence of B chromosomes was confirmed by classical cytogenetic and molecular with the use of chromosome specific probe B constructed by chromosome microdissection and amplification Degenerated Oligonucleotids Primers (DOP-PCR) and subsequent in situ hybridization (FISH). Geometric morphometric analysis were performed separately for males and females with and without the presence of chromosomes B. The results indicate that the sex ratio varied seasonally having an increased number of males compared to females. Hermaphrodite individuals were found at a frequency of 7.7%. The reproductive period is characterized by an atypical reproductive peak during the winter period, beyond the period observed pattern from the spring in September. The presence of B chromosomes has been linked to possible reproductive strategies in different populations studied, especially in relation to energy intake and stages of gonadal development. There morphometric differences both between individuals female and male subjects with and without chromosome B. / Astyanax scabripinnis é uma espécie encontrada na Região Neotropical, essa espécie forma demes populacionais isolados em cabeceiras de riachos. Ela é taxonomicamente mal resolvida, mas se apresenta como interessante modelo para o estudo da presença de cromossomos B. A ocorrência desses cromossomos em A. scabripinnis pode estar associada a diversos fatores ambientais e populacionais, embora seja pouco esclarecido sobre a manutenção parasítica ou possíveis efeitos heteróticos desses cromossomos. A biologia reprodutiva relacionada à presença de cromossomo B em A. scabripinnis nunca foi abordada. Assim, foi objeto deste trabalho investigar se aspectos do processo reprodutivo, fundamental para o valor adaptativo, podem estar relacionados à presença de cromossomos B em A. scabripinnis. As coletas foram realizadas trimestralmente entre os anos de 2012 e 2013 na região de Campos do Jordão, São Paulo, Brasil (22°40`49,5”S, 45°23`31,9” W), no Córrego da Fazenda Lavrinha, bacia do rio Paraíba do Sul. As gônadas foram classificadas macro e microscopicamente segundo estádios de desenvolvimento. Estabeleceu-se sazonalmente a proporção sexual da população nas diferentes amostragens. Foi calculada a relação gonadossomática (RGS) e a relação hepatossomática (RHS) separadamente para fêmeas com e sem cromossomo B. A presença de cromossomos B foi confirmada por meio da citogenética clássica e molecular com o emprego de sonda específica do cromossomo B construída por microdissecção cromossômica e amplificação por Degenerated Oligonucleotids Primers (DOP-PCR) e posterior hibridação fluorescente in situ (FISH). Análises de morfometria geométrica foram realizadas separadamente para fêmeas e machos com e sem a presença de cromossomos B. Os resultados indicam que a proporção sexual variou sazonalmente havendo um aumento do número dos machos em relação às fêmeas. Foram encontrados indivíduos hermafroditas na frequência de 7,7%. O período reprodutivo é caracterizado por um pico de reprodução atípico no período do inverno, além do período padrão observado a partir da primavera no mês de setembro. A presença de cromossomos B foi relacionada a possíveis estratégias reprodutivas distintas na população estudada, especialmente em relação ao aporte energético e estádios de desenvolvimento gonadal. Há diferenças morfométrica tanto entre indivíduos fêmeas e machos como entre indivíduos com e sem cromossomo B.
|
| 22 |
An Analysis of Nicotine Exacerbation of Reductions in PPI in a Rodent Model of Schizophrenia.Maple, Amanda Marie 05 May 2007 (has links)
Prepulse inhibition (PPI) is an operational measure of sensorimotor gating and is known to be reduced when the dopamine D2 receptor is activated. We used a rodent model of psychosis in which increases in dopamine D2 receptor sensitivity are produced through neonatal quinpirole (a dopamine D2 / D3 agonist) treatment to rats. Rats were administered quinpirole (1mg/kg) or saline from postnatal day (P) 1-21. Rats were raised to adulthood and tested on PPI. Results showed that neonatal quinpirole treatment produced a significant reduction in PPI, and nicotine exacerbated this reduction. This reduction was partially blocked by the nicotinic antagonist mecamylamine. Brain tissue was analyzed for regulators of G-protein signaling (RGS) and results showed that neonatal quinpirole significantly decreased RGS9, but increased RGS17 as compared to controls. These results appear to indicate that the G-protein couples more efficiently to the D2 receptor, and nicotine exacerbates PPI deficits in D2 receptor-primed rats.
|
| 23 |
Role of molecular chaperones in G protein B5-Regulator of G protein signaling dimer assembly and G protein By dimer specificityHowlett, Alyson Cerny 02 April 2009 (has links) (PDF)
In order for G protein signaling to occur, the G protein heterotrimer must be assembled from its nascent polypeptides. The most difficult step in this process is the formation of the Gβγ dimer from the free subunits since both are unstable in the absence of the other. Recent studies have shown that phosducin-like protein (PhLP1) works as a co-chaperone with the cytosolic chaperonin complex (CCT) to fold Gβ and mediate its interaction with Gγ. However, these studies did not address questions concerning the scope of PhLP1 and CCT-mediated Gβγ assembly, which are important questions given that there are four Gβs that form various dimers with 12 Gγs and a 5th Gβ that dimerizes with the four regulator of G protein signaling (RGS) proteins of the R7 family. The data presented in Chapter 2 shows that PhLP1 plays a vital role in the assembly of Gγ2 with all four Gβ1-4 subunits and in the assembly of Gβ2 with all twelve Gγ subunits, without affecting the specificity of the Gβγ interactions. The results of Chapter 3 show that Gβ5-RGS7 assembly is dependent on CCT and PhLP1, but the apparent mechanism is different from that of Gβγ. PhLP1 seems to stabilize the interaction of Gβ5 with CCT until Gβ5 is folded, after which it is released to allow Gβ5 to interact with RGS7. These findings point to a general role for PhLP1 in the assembly of all Gβγ combinations, and suggest a CCT-dependent mechanism for Gβ5-RGS7 assembly that utilizes the co-chaperone activity of PhLP1 in a unique way. Chapter 4 discusses PhLP2, a recently discovered essential protein, and member of the Pdc family that does not play a role in G protein signaling. Several studies have indicated that PhLP2 acts as a co-chaperone with CCT in the folding of actin, tubulin, and several cell cycle and pro-apoptotic proteins. In a proteomics screen for PhLP2A interacting partners, α-tubulin, 14-3-3, elongation factor 1α, and ribosomal protein L3 were found. Further proteomics studies indicated that PhLP2A is a phosphoprotein that is phosphorylated by CK2 at threonines 47 and 52.
|
| 24 |
FBXO44-MEDIATED DEGRADATION OF RGS2Harrison J McNabb (15361621) 27 April 2023 (has links)
<p> G Protein Coupled Receptor (GPCR) signaling plays a key role in intercellular communication and regulates many physiological processes relevant to disease. Approximately 30-40% of all FDA approved drugs target GPCR pathways, but limitations and off-target side effects remain obstacles. Regulator of G protein Signaling (RGS) proteins negatively modulate GPCR signaling by accelerating deactivation of the Gα subunit and thus represent a novel alternative to current approaches. While research on RGS proteins and how they are regulated has expanded rapidly, there are still gaps in knowledge for some members of the RGS family. One example is RGS2, which is selective for Gαq signaling. Lowered RGS2 levels are implicated in numerous diseases, and while the E3 ligase responsible for facilitating degradation of RGS2 has been identified more work needs to be done to viably drug it to enhance RGS2 protein levels. In this thesis, I explore how FBXO44, an E3 ligase substrate recognition component responsible for RGS2 degradation, interacts with RGS2 to explore approaches to inhibit degradation.</p>
<p><br></p>
<p>While the FBXO44-RGS2 interaction has been demonstrated previously, the degron sequence of RGS2 remained unknown. We hypothesized that FBXO44 binds RGS2 at its Nterminus and investigated this using N-terminally truncated RGS2 constructs. Our results indicated that FBXO44 binds between residues 5 and 16 of RGS2, as removal of these stabilized RGS2 against proteasomal degradation. Based on these results we designed a peptide microarray to identify important residues and properties for FBXO44 in vitro and found that Cys13 is essential for FBXO44 binding.</p>
<p><br></p>
<p>We also developed and optimized a high-throughput split luciferase screen to identify potential inhibitors of the FBXO44-RGS2 interaction. After forming a cell-line stably expressing tagged FBXO44 and RGS2 and optimizing assay condition, we achieved a robust assay for screening as determined by Z’-factor. <br>
</p>
|
| 25 |
Retorisk genreanalys som verktygför utvärdering av AI : En jämförelse mellan olika sätt att leda GPT-4 motatt skapa ändamålsenlig kriskommunikationKempe, David January 2023 (has links)
In this thesis, I delve into how Rhetorical Genre Study and Systemic-Functional Grammar can be used to assess the extent to which GPT-4 adheres to generic features and can be deemed adapted for its function. The objective is to establish a systematic model for objectively evaluating the degree to which AI-generated text is suitable for its intended purpose. To achieve this, I perform a rhetorical genre analysis on a crisis communication genre, which I subsequently quantify. I utilize the concept of topoi to pinpoint the arguments that serve to fulfill the functions of crisis communication. Subsequently, I prompt GPT-4 to produce texts within the genre and contrast them with my discoveries. Alongside this, I investigate the disparate results produced when using text and meta-text as input. The findings reveal a functional model to appraise the degree of text adaptation for its purpose within the analyzed genre. Although the model necessitates further fine-tuning, it effectively distinguishes nongeneric texts. The scope of the material selected was too limited to indicate any disparities in outcomes between different types of input. However, all input models generated texts that substantially conformed to the generic features.
|
| 26 |
O Gaúcho, a Dominação Masculina e a Educação na Fronteira Sul-Riograndense: o Passado no PresenteGuedes, Berenice Lagos 22 March 2004 (has links)
Made available in DSpace on 2014-08-20T13:48:10Z (GMT). No. of bitstreams: 1
Berenice Lagos Guedes_Dissertacao.PDF: 14155869 bytes, checksum: 2b2f1c2bd147dd53553e89c10f58be19 (MD5)
Previous issue date: 2004-03-22 / This paper intends to analyse some effects of male dominance on the borderline area between Rio Grande do Sul, Brazil and the Eastern Republic of Uruguay upon the educational processes and professional carriers of such student-teachers who were attending the Program for Teacher Formation on the Job in the area of Pedagogy sponsored by the Universidade da Região da Campanha (Southernmost Plains Area University)/URCAMP/Bagé/RS, during the month of July 2003. These subjects were either married or engaged in a stable marital-like union and they are expected to build the present day local History of Education. It is comon knowledge that male dominance is inherited from the patriarchal family unit and the androcentric society that significantly influenced the formation of the gaucho society all along the XIXth Century; such a domination process was extended throughout the XXth Century until it began to peter out during the last decades. However, in the borderline area between southern Rio Grande do Sul and northern Uruguay it still makes its presence shown in the first years of the XXIst Century, due to this area peculiarities and by means of the Gaucho myth perpetuation. Gender relationships (particularly those happening within domestic confines) and their effects upon the lives of such female teachers who actually build present day regional History of Education were analysed. This situation is most evident in the country districts, although it is still present in urban areas, especially in the borderline small to middle-size counties. The methodology employed was embased upon the application of open and closed questionnaires, semi-structured interviews for recording subjects memories, along with a reaction-provoking visual technique. Research focal points were the manifestation of Rio Grande do Sul State native imagery, the social build-up of the gaucho culture, and male dominance, along with such interfaces that were built toward participants lives and the historical development of their trajectories on the History of Education area. Research adopted a quanti-qualitative approach, biased toward the qualitative side and data was analysed in a descriptive way. The urgent need for further studies on the gender relationships on Academe to bolster up organized resistance movements leading to the writing of a new local History of Education was perceived. / Este trabalho analisa algumas das repercussões da dominação masculina na região da fronteira do Rio Grande do Sul com o Uruguai no processo educacional e na trajetória profissional das professoras -alunas que cursaram o Programa de Formação de Professores em Serviço/Pedagogia oferecido pela Universidade da Região da Campa nha/URCAMP/Bagé/RS em julho de 2003, casadas ou em união estável e que constroem a História da Educação local no presente. Sabe-se que a dominação masculina é herança da família patriarcal e da sociedade androcêntrica que influenciou significativamente a formação social do gaúcho no século XIX. Verificou-se que esta se estendeu pelo século XX, parecendo abrandar-se no final do século. Entretanto, na região da fronteira do Rio Grande do Sul com o Uruguai esta ainda está presente, em pleno início do século XXI, pelas peculiaridades da região e através da perpetuação do Mito do gaúcho. Foram analisadas as relações de gênero (que se dão principalmente no espaço doméstico) e suas repercussões na vida de professoras que constroem a História da Educação regional no presente. Verificou-se que esta situação se evidencia mais na zona rural, embora também esteja presente na zona urbana dos pequenos e médios municípios da fronteira. A metodologia
baseou-se na aplicação de questionários com questões abertas e fechadas, entrevistas semiestruturadas para captação da memória das entrevistadas e aplicação de uma técnica instigadora. Como eixos de pesquisa trabalhou-se com as manifestações do imaginário Sul-Rio-Grandense, a Formação Social do Gaúcho, a Dominação Masculina e suas interfaces na
vida das participantes e a construção histórica da sua trajetória na História da Educação. A pesquisa seguiu uma abordagem quanti-qualitativa, com predomínio da qualitativa, sendo os dados analisados de forma descritiva. Percebeu-se a necessidade urgente de estudos sobre relações de gênero na Academia, com vistas à construção de nova História da Educação Regional.
|
| 27 |
RLtools : A Toolset For Visual Language Application Development Based on Relational GrammarsSuresh, B G 07 1900 (has links) (PDF)
No description available.
|
| 28 |
Methodenentwicklung zur Simulation von Strömungen mit freier Oberfläche unter dem Einfluss elektromagnetischer WechselfelderBeckstein, Pascal 16 February 2018 (has links) (PDF)
Im Bereich der industriellen Metallurgie und Kristallzüchtung treten bei zahlreichen Anwendungen, wo magnetische Wechselfelder zur induktiven Beeinflussung von leitfähigen Werkstoffen eingesetzt werden, auch Strömungen mit freier Oberfläche auf. Das Anwendungsspektrum reicht dabei vom einfachen Aufschmelzen eines Metalls in einem offenen Tiegel bis hin zur vollständigen Levitation. Auch der sogenannte RGS-Prozess, ein substratbasiertes Kristallisationsverfahren zur Herstellung siliziumbasierter Dünnschichtmaterialien, ist dafür ein Beispiel. Um bei solchen Prozessen die Interaktion von Magnetfeld und Strömung zu untersuchen, ist die numerische Simulationen ein wertvolles Hilfsmittel. Für beliebige dreidimensionale Probleme werden entsprechende Berechnungen bisher durch eine externe Kopplung kommerzieller Programme realisiert, die für Magnetfeld und Strömung jeweils unterschiedliche numerische Techniken nutzen. Diese Vorgehensweise ist jedoch im Allgemeinen mit unnötigem Rechenaufwand verbunden. In dieser Arbeit wird ein neu entwickelter Methodenapparat auf Basis der FVM vorgestellt, mit welchem sich diese Art von Berechnungen effizient durchführen lassen. Mit der Implementierung dieser Methoden in foam-extend, einer erweiterten Version der quelloffenen Software OpenFOAM, ist daraus ein leistungsfähiges Werkzeug in Form einer freien Simulationsplattform entstanden, welches sich durch einen modularen Aufbau leicht erweitern lässt. Mit dieser Plattform wurden in foam-extend auch erstmalig dreidimensionale Induktionsprozesse im Frequenzraum gelöst.
|
| 29 |
Methodenentwicklung zur Simulation von Strömungen mit freier Oberfläche unter dem Einfluss elektromagnetischer WechselfelderBeckstein, Pascal 08 January 2018 (has links)
Im Bereich der industriellen Metallurgie und Kristallzüchtung treten bei zahlreichen Anwendungen, wo magnetische Wechselfelder zur induktiven Beeinflussung von leitfähigen Werkstoffen eingesetzt werden, auch Strömungen mit freier Oberfläche auf. Das Anwendungsspektrum reicht dabei vom einfachen Aufschmelzen eines Metalls in einem offenen Tiegel bis hin zur vollständigen Levitation. Auch der sogenannte RGS-Prozess, ein substratbasiertes Kristallisationsverfahren zur Herstellung siliziumbasierter Dünnschichtmaterialien, ist dafür ein Beispiel. Um bei solchen Prozessen die Interaktion von Magnetfeld und Strömung zu untersuchen, ist die numerische Simulationen ein wertvolles Hilfsmittel. Für beliebige dreidimensionale Probleme werden entsprechende Berechnungen bisher durch eine externe Kopplung kommerzieller Programme realisiert, die für Magnetfeld und Strömung jeweils unterschiedliche numerische Techniken nutzen. Diese Vorgehensweise ist jedoch im Allgemeinen mit unnötigem Rechenaufwand verbunden. In dieser Arbeit wird ein neu entwickelter Methodenapparat auf Basis der FVM vorgestellt, mit welchem sich diese Art von Berechnungen effizient durchführen lassen. Mit der Implementierung dieser Methoden in foam-extend, einer erweiterten Version der quelloffenen Software OpenFOAM, ist daraus ein leistungsfähiges Werkzeug in Form einer freien Simulationsplattform entstanden, welches sich durch einen modularen Aufbau leicht erweitern lässt. Mit dieser Plattform wurden in foam-extend auch erstmalig dreidimensionale Induktionsprozesse im Frequenzraum gelöst.
|
Page generated in 0.0211 seconds