• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 180
  • 38
  • 28
  • 17
  • 16
  • 15
  • 9
  • 6
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 386
  • 138
  • 57
  • 56
  • 53
  • 45
  • 35
  • 26
  • 26
  • 24
  • 23
  • 23
  • 21
  • 21
  • 20
  • 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

Mechanisms of iron acquisition employed by Neisseria gonorrhoeae for survival within cervical epithelial cells /

Hagen, Tracey Ann, January 2006 (has links)
Thesis (Ph. D.)--Virginia Commonwealth University, 2006. / Prepared for: Dept. of Microbiology and Immunology. Bibliography: leaves 134-165.
62

Non-militarization of the final frontier tracing the evolution of norms in outer space / Non-militarization of the final frontier tracing the evolution of norms in outer space

Mráz, Pavel January 2014 (has links)
This diploma thesis critically examines traditional positivist interpretations concerning the birth of four core norms of the current legal regime governing activities of states in Outer Space: a) non-militarization, b) peaceful use, c) non- appropriation, and d) freedom of access. Traditional interpretations often explicate the emergence of the aforementioned principles in static terms, either as a result of universal aspirations of mankind to peaceful explore the final frontier, or alternatively as a product of rational calculations of self-interested states. Analysis of the first decade of the space age through the lens of post-structural genealogical method proposed by Richard Price reveals a much more complex picture. Application of critical genealogical approach indicates that the emergence of the four norms in question was contingent on the presence of particular historical circumstances and cognitive structures of the Cold War: a) fear of nuclear weapons, b) policy of containment, c) trauma of the Second World War, and d) highly politicized outer space discourse due to the presence of the space race. The findings also indicate that without the presence of the particular historical circumstances and cognitive structures that necessitated their emergence, the four principles in question are...
63

Structure of an Inner Membrane Protein Required for PhoPQ-Regulated Increases in Outer Membrane Cardiolipin

Fan, Junping, Petersen, Erik M., Hinds, Thomas R., Zheng, Ning, Miller, Samuel I. 01 January 2020 (has links)
The Salmonella enterica subsp. enterica serovar Typhimurium PhoPQ two-component system is activated within the intracellular phagosome environment, where it promotes remodeling of the outer membrane and resistance to innate immune antimicrobial peptides. Maintenance of the PhoPQ-regulated outer membrane barrier requires PbgA, an inner membrane protein with a transmembrane domain essential for growth, and a periplasmic domain required for PhoPQ-activated increases in outer membrane cardiolipin. Here, we report the crystal structure of cardiolipin-bound PbgA, adopting a novel transmembrane fold that features a cardiolipin binding site in close proximity to a long and deep cleft spanning the lipid bilayer. The end of the cleft extends into the periplasmic domain of the protein, which is structurally coupled to the transmembrane domain via a functionally critical C-terminal helix. In conjunction with a conserved putative catalytic dyad situated at the middle of the cleft, our structural and mutational analyses suggest that PbgA is a multifunction membrane protein that mediates cardiolipin transport, a function essential for growth, and perhaps catalysis of an unknown enzymatic reaction. IMPORTANCE Gram-negative bacteria cause many types of infections and have become increasingly resistant to available antibiotic drugs. The outer membrane serves as an important barrier that protects bacteria against antibiotics and other toxic compounds. This outer membrane barrier function is regulated when bacteria are in host environments, and the protein PbgA contributes significantly to this increased barrier function by transporting cardiolipin to the outer membrane. We determined the crystal structure of PbgA in complex with cardiolipin and propose a model for its function. Knowledge of the mechanisms of outer membrane assembly and integrity can greatly contribute to the development of new and effective antibiotics, and this structural information may be useful in this regard.
64

A feasibility analysis of a directly sun-pumped carbon dioxide laser in space

Morimoto, Seiichi 01 January 1979 (has links)
The possibility of using sunlight to pump a CW carbon dioxide laser has been analyzed. Such a laser could be of interest for such applications as space communication and power transmission. In order to optically pump CO2 using sunlight, the intense vibrational-rotational absorption bands of CO2 in the 4.3 micron spectral region would have to be utilized. The total pumping power from sunlight can be calculated from the known data of the solar spectral irradiance outside the atmosphere and the infrared absorption by carbon dioxide at 4.3 microns. The pumping power is proportional to the collector area of the sunlight and is also dependent on the characteristics of the absorbing gas mixture, such as the gas composition, the gas temperature, the total pressure of the mixture, the partial pressure of CO2, and the absorption path length of the sunlight in the gas. To analyze the carbon dioxide laser system, a thermodynamic approach was used with a simplified CO2 chemical kinetic model. The gain and saturation intensity were obtained by solving a set of energy balance equations which describe the processes among the various vibrational modes. From those results, along with the estimated cavity losses, the output power was found.
65

Space--Our Future: A Script for Group Interpretation

Bishop, Laura M. (Laura Maria) 08 1900 (has links)
The purpose of this thesis has been to prepare a group interpretation script based on the National Aeronautics and Space Administration and its major manned programs. The script is designed to inform high school students and the general public of the space program. Available literature on oral interpretation and readers theatre have been investigated with particular attention given to the value of readers theatre as a means of instruction. Questionnaires were circulated among aerospace professors throughout the country and companies involved in the space industry. In their responses, aerospace company officials indicate strong support of this thesis and indicate a pressing need for such an informative script.
66

Identification of Francisella tularensis Outer Membrane Proteins

Melillo, Amanda Adeline 20 July 2005 (has links)
No description available.
67

Designing for Space, on Earth: Creating More Livable Extraterrestrial Habitats Through Architectural Design

Badger, Jeffrey R. 17 September 2012 (has links)
No description available.
68

A conservative party: pots and people in the Hebridean Neolithic

22 October 2018 (has links)
No / Recent analysis of the ceramic assemblage from the Neolithic loch islet settlement of Eilean Dòmhnuill, North Uist, in the Western Isles of Scotland has highlighted the intense conservatism of the potting traditions over a period of more than 800 years. Hebridean Neolithic pottery exhibits clear relationships with pottery from Argyll, Arran, and Bute, as well as Orkney and the north-east mainland of Scotland. It appears to have developed a distinctive, often decoratively elaborate regional form very soon after its initial appearance, which subsequently appears to have undergone little or no significant change until the introduction of Grooved Ware in the early 3rd millennium BC. An association exists between large assemblages of elaborately decorated Hebridean pottery and a number of artificial islets in freshwater lochs, some very small and producing little or no evidence for domestic activities. This might be explained by the importance of commensality in mediating relations between small communities in the Western Isles at such sites following the introduction of agriculture in the 2nd quarter of the 4th millennium BC. The conservatism and stasis evident at Eilean Dòmhnuill, in the face of environmental decline, raises wider issues around the adaptive capabilities of the first farming communities prior to significant social changes in the earlier 3rd millennium BC. / University of Bradford
69

Settler Colonialism in U.S. Popular Media as Influencing Perceptions of Material Culture and Museum Ethics

Patrick, Cara Rose 12 June 2024 (has links)
The everyday person living in the United States does not first encounter ethics of material culture and collecting solely by visiting a museum. This MA Thesis seeks to look at how action-adventure "treasure-hunting" media introduces people to fields such as archaeology, anthropology, and museum studies through entertainment media. Frameworks of settler colonialism are used to understand the intentionality behind and subsequent impact of these films in a US-based context. Media effects theories of cultivation, framing, and agenda setting are also applied to understand how messages are facilitated through media such as the Indiana Jones (1981-2024), National Treasure (2004-2023), and "Outer Banks" (2020- ) franchises. The core aim for future thought and research is to understand how museums and filmmakers alike may more ethically and equitably represent people and material culture. / Master of Arts / In the United States, the allure of museums is supported by action-adventure "treasure-hunting" media, like the Indiana Jones (1981-2024), National Treasure (2004-2023), and "Outer Banks" (2020- ) franchises. Settler colonial ideologies, which seek to legitimize white settlers' relationship to the land in the United States, are present in the production and consumption of this media. Communication-based media effects theories, which explain how media messages influence an audience's point of view as a result of the media they consume, support that there is a relationship between action-adventure "treasure-hunting" media and museums on audience outlook.
70

Comparação entre Neisseria meningitidis e Neisseria lactamica: cinética do cultivo e potencial antigênico de OMV e frações. / Comparison between Neisseria meningitidis and Neisseria lactamica: kinetics of bacterial growth and analysis of the antigenic potential of OMV and fractions.

Salustiano, Giovanna Ferreira Costa Leão 24 April 2015 (has links)
Neste trabalho foi avaliado o potencial antigênico das vesículas de membrana externa, OMV, de N. meningitidis, das OMV e componetes protéicos selecionados de N. lactamica. Para tal foram realizados cultivos de ambas as espécies em biorreatores, ensaios de imunização em camundongos, análises de espectrometria de massas, e análises de tamanho das partículas, polidispersabilidade e potencial zeta. As análises da cinética de cultivos levaram a dados inéditos possibilitando uma nova discussão sobre o metabolismo e sobre a produtividade de OMV destas bactérias. N. lactamica obteve valores 5 vezes maiores de concentração máxima de OMV de 152 mg/L e 2,5 vezes maiores de produtividade de OMV de 0,32 g/L.h comparado aos obtidos para N. meningitidis nas mesmas condições de cultivo. OMV obtidas nos cultivos de ambas e componentes proteicos de N. lactamica foram utilizadas para imunizar camundongos com 3 doses subcutâneas. Ensaios de imunoblote e ELISA demonstraram que soros gerados contra as proteínas isoladas de N. lactamica foram reativos com proteínas de N. meningitidis, assim como o soro anti-OMV de N. lactamica que reagiu com 6 proteínas de N. meningitidis, as proteínas de membrana App, Omp85, PilQ, PorA, PorB, e ComL ou Opa/Opc. Análises de espectrometria de massas identificaram 229 proteínas na OMV de N. lactamica, sendo 77 proteínas de membrana e 243 proteínas de N. meningitidis, sendo 54 proteínas de membrana. Os resultados obtidos neste trabalho sugerem a possibilidade do uso das OMV de Neisseria lactamica como abordagem alternativa para o desenvolvimento de vacinas contra a doença meningocócica. / In these studies we evaluated the antigenic potential of outer membrane vesicles (OMV) from N. meningitidis, OMV from N. lactamica and proteic components from N. lactamica. Outer membrane vesicles were obtained from cultures of both species in bioreactors. Immunization tests were conducted in mice. Western-blotting and ELISA techniques were used to evaluate the cross-reactivity of murine sera against outer-membrane proteins from Neisseria meningitidis and Neisseria lactamica. Analysis of mass spectrometry and determination of particle size, polydispersity and zeta potential were also performed. Analysis of bacterial growth kinetics led to new data enabling a discussion about metabolism and OMV productivity. When both species were cultured in the same medium OMV concentration of N. lactamica (152 mg/L) is 5 times higher than that in N. meningitidis and OMV productivity of N. lactamica (0.32 g/L.h) is 2.5 times higher. Mice were vaccinated subcutaneously with 3 doses of OMV from both species and proteins from N. lactamica. These vaccines induced antibodies against N. meningitidis proteins. By mass spectrometry it was possible to identify these membrane proteins as App, Omp85, PilQ, PorA, PorB, and ComL or Opa/Opc. Mass spectrometry analyses also identified 229 proteins in N. lactamica OMV, with 77 predicted as membrane proteins and 243 in N. meningitidis OMV with 54 predicted as membrane proteins. Ours results suggested that OMV from Neisseria lactamica provides protection against N. meningitidis and could be used as an alternative approach for the development of a vaccine against meningococcal disease.

Page generated in 0.0529 seconds