Academic literature on the topic 'RNA flexibility'
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Journal articles on the topic "RNA flexibility"
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Hagerman, Paul J. "FLEXIBILITY OF RNA." Annual Review of Biophysics and Biomolecular Structure 26, no. 1 (June 1997): 139–56. http://dx.doi.org/10.1146/annurev.biophys.26.1.139.
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Darst, S. A., N. Opalka, P. Chacon, A. Polyakov, C. Richter, G. Zhang, and W. Wriggers. "Conformational flexibility of bacterial RNA polymerase." Proceedings of the National Academy of Sciences 99, no. 7 (March 19, 2002): 4296–301. http://dx.doi.org/10.1073/pnas.052054099.
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Sutton, Julie, and Lois Pollack. "RNA Flexibility Depends on Structural Context." Biophysical Journal 108, no. 2 (January 2015): 27a. http://dx.doi.org/10.1016/j.bpj.2014.11.174.
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Warden, Meghan S., Kai Cai, Gabriel Cornilescu, Jordan E. Burke, Komala Ponniah, Samuel E. Butcher, and Steven M. Pascal. "Conformational flexibility in the enterovirus RNA replication platform." RNA 25, no. 3 (December 21, 2018): 376–87. http://dx.doi.org/10.1261/rna.069476.118.
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Zhuo, Chen, Chengwei Zeng, Rui Yang, Haoquan Liu, and Yunjie Zhao. "RPflex: A Coarse-Grained Network Model for RNA Pocket Flexibility Study." International Journal of Molecular Sciences 24, no. 6 (March 13, 2023): 5497. http://dx.doi.org/10.3390/ijms24065497.
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RNA regulates various biological processes, such as gene regulation, RNA splicing, and intracellular signal transduction. RNA’s conformational dynamics play crucial roles in performing its diverse functions. Thus, it is essential to explore the flexibility characteristics of RNA, especially pocket flexibility. Here, we propose a computational approach, RPflex, to analyze pocket flexibility using the coarse-grained network model. We first clustered 3154 pockets into 297 groups by similarity calculation based on the coarse-grained lattice model. Then, we introduced the flexibility score to quantify the flexibility by global pocket features. The results show strong correlations between the flexibility scores and root-mean-square fluctuation (RMSF) values, with Pearson correlation coefficients of 0.60, 0.76, and 0.53 in Testing Sets I–III. Considering both flexibility score and network calculations, the Pearson correlation coefficient was increased to 0.71 in flexible pockets on Testing Set IV. The network calculations reveal that the long-range interaction changes contributed most to flexibility. In addition, the hydrogen bonds in the base–base interactions greatly stabilize the RNA structure, while backbone interactions determine RNA folding. The computational analysis of pocket flexibility could facilitate RNA engineering for biological or medical applications.
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Hyeon, Changbong, Ruxandra I. Dima, and D. Thirumalai. "Size, shape, and flexibility of RNA structures." Journal of Chemical Physics 125, no. 19 (November 21, 2006): 194905. http://dx.doi.org/10.1063/1.2364190.
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Kilburn, John D., Joon Ho Roh, Liang Guo, Robert M. Briber, and Sarah A. Woodson. "RNA Flexibility and Folding in Crowded Solutions." Biophysical Journal 102, no. 3 (January 2012): 644a. http://dx.doi.org/10.1016/j.bpj.2011.11.3506.
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Rau, M., W. T. Stump, and K. B. Hall. "Intrinsic flexibility of snRNA hairpin loops facilitates protein binding." RNA 18, no. 11 (September 25, 2012): 1984–95. http://dx.doi.org/10.1261/rna.035006.112.
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Fairman, Connor W., Andrew M. L. Lever, and Julia C. Kenyon. "Evaluating RNA Structural Flexibility: Viruses Lead the Way." Viruses 13, no. 11 (October 22, 2021): 2130. http://dx.doi.org/10.3390/v13112130.
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Our understanding of RNA structure has lagged behind that of proteins and most other biological polymers, largely because of its ability to adopt multiple, and often very different, functional conformations within a single molecule. Flexibility and multifunctionality appear to be its hallmarks. Conventional biochemical and biophysical techniques all have limitations in solving RNA structure and to address this in recent years we have seen the emergence of a wide diversity of techniques applied to RNA structural analysis and an accompanying appreciation of its ubiquity and versatility. Viral RNA is a particularly productive area to study in that this economy of function within a single molecule admirably suits the minimalist lifestyle of viruses. Here, we review the major techniques that are being used to elucidate RNA conformational flexibility and exemplify how the structure and function are, as in all biology, tightly linked.
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Hetzke, Thilo, Marc Vogel, Dnyaneshwar B. Gophane, Julia E. Weigand, Beatrix Suess, Snorri Th Sigurdsson, and Thomas F. Prisner. "Influence of Mg2+ on the conformational flexibility of a tetracycline aptamer." RNA 25, no. 1 (October 18, 2018): 158–67. http://dx.doi.org/10.1261/rna.068684.118.
Full textDissertations / Theses on the topic "RNA flexibility"
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Panei, Francesco Paolo. "Advanced computational techniques to aid the rational design of small molecules targeting RNA." Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS106.
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Les molécules d'ARN sont devenues des cibles thérapeutiques majeures, et le ciblage par petites molécules se révèle particulièrement prometteur. Cependant, malgré leur potentiel, le domaine est encore en développement, avec un nombre limité de médicaments spécifiquement conçus pour l'ARN. La flexibilité intrinsèque de l'ARN, bien qu'elle constitue un obstacle, introduit des opportunités thérapeutiques que les outils computationnels actuels ne parviennent pas pleinement à exploiter malgré leur prédisposition. Le projet de cette thèse est de construire un cadre computationnel plus complet pour la conception rationnelle de composés ciblant l'ARN. La première étape pour toute approche structure-based est l'analyse des connaissances structurales disponibles. Cependant, il manquait une base de données complète, organisée et régulièrement mise à jour pour la communauté scientifique. Pour combler cette lacune, j'ai créé HARIBOSS, une base de données de toutes les structures expérimentalement déterminées des complexes ARN-petites molécules extraites de la base de données PDB. Chaque entrée de HARIBOSS, accessible via une interface web dédiée (https://hariboss.pasteur.cloud), est annotée avec les propriétés physico-chimiques des ligands et des poches d'ARN. Cette base de données constamment mise à jour facilitera l'exploration des composés drug-like liées à l'ARN, l'analyse des propriétés des ligands et des poches, et en fin de compte, le développement de stratégies in silico pour identifier des petites molécules ciblant l'ARN. Lors de sa sortie, il a été possible de souligner que la majorité des poches de liaison à l'ARN ne conviennent pas aux interactions avec des molécules drug-like. Cela est dû à une hydrophobicité moindre et une exposition au solvant accrue par rapport aux sites de liaison des protéines. Cependant, cela résulte d'une représentation statique de l'ARN, qui peut ne pas capturer pleinement les mécanismes d'interaction avec de petites molécules. Il était nécessaire d'introduire des techniques computationnelles avancées pour une prise en compte efficace de la flexibilité de l'ARN. Dans cette direction, j'ai mis en œuvre SHAMAN, une technique computationnelle pour identifier les sites de liaison potentiels des petites molécules dans les ensembles structuraux d'ARN. SHAMAN permet d'explorer le paysage conformationnel de l'ARN cible par des simulations de dynamique moléculaire atomistique. Dans le même temps, il identifie efficacement les poches d'ARN en utilisant de petits fragments dont l'exploration de la surface de l'ARN est accélérée par des techniques d'enhanced sampling. Dans un ensemble de données comprenant divers riboswitches structurés ainsi que de petits ARN viraux flexibles, SHAMAN a précisément localisé des poches résolues expérimentalement, les classant les régions d’interaction préférées. Notamment, la précision de SHAMAN est supérieure à celle d'autres outils travaillant sur des structures statiques d'ARN dans un scénario réaliste de découverte de médicaments où seules les structures apo de la cible sont disponibles. Cela confirme que SHAMAN est une plateforme robuste pour les futures initiatives de conception de médicaments ciblant l'ARN avec de petites molécules, en particulier compte tenu de sa pertinence potentielle dans les campagnes de criblage virtuel. Dans l'ensemble, ma recherche contribue à améliorer notre compréhension et notre utilisation de l'ARN en tant que cible pour les médicaments à petites molécules, ouvrant la voie à des stratégies thérapeutiques plus efficaces dans ce domaine en évolutionRNA molecules have recently gained huge relevance as therapeutic targets. The direct targeting of RNA with small molecule drugs emerges for its wide applicability to different classes of RNAs. Despite this potential, the field is still in its infancy and the number of available RNA-targeted drugs remains limited. A major challenge is constituted by the highly flexible and elusive nature of the RNA targets. Nonetheless, RNA flexibility also presents unique opportunities that could be leveraged to enhance the efficacy and selectivity of newly designed therapeutic agents. To this end, computer-aided drug design techniques emerge as a natural and comprehensive approach. However, existing tools do not fully account for the flexibility of the RNA. The project of this PhD work aims to build a computational framework toward the rational design of compounds targeting RNA. The first essential step for any structure-based approach is the analysis of the available structural knowledge. However, a comprehensive, curated, and regularly updated repository for the scientific community was lacking. To fill this gap, I curated the creation of HARIBOSS ("Harnessing RIBOnucleic acid - Small molecule Structures"), a database of all the experimentally-determined structures of RNA-small molecule complexes retrieved from the PDB database. HARIBOSS is available via a dedicated web interface (https://hariboss.pasteur.cloud), and is regularly updated with all the structures resolved by X-ray, NMR, and cryo-EM, in which ligands with drug-like properties interact with RNA molecules. Each HARIBOSS entry is annotated with physico-chemical properties of ligands and RNA pockets. HARIBOSS repository, constantly updated, will facilitate the exploration of drug-like compounds known to bind RNA, the analysis of ligands and pockets properties and, ultimately, the development of in silico strategies to identify RNA-targeting small molecules. In coincidence of its release, it was possible to highlight that the majority of RNA binding pockets are unsuitable for interactions with drug-like molecules, attributed to the lower hydrophobicity and increased solvent exposure compared to protein binding sites. However, this emerges from a static depiction of RNA, which may not fully capture their interaction mechanisms with small molecules. In a broader perspective, it was necessary to introduce more advanced computational techniques for an effective accounting of RNA flexibility in the characterization of potential binding sites. In this direction, I implemented SHAMAN, a computational technique to identify potential small-molecule binding sites in RNA structural ensembles. SHAMAN enables the exploration of the target RNA conformational landscape through atomistic molecular dynamics. Simultaneously, it efficiently identifies RNA pockets using small probe compounds whose exploration of the RNA surface is accelerated by enhanced-sampling techniques. In a benchmark encompassing diverse large, structured riboswitches as well as small, flexible viral RNAs, SHAMAN accurately located experimentally resolved pockets, ranking them as preferred probe hotspots. Notably, SHAMAN accuracy was superior to other tools working on static RNA structures in the realistic drug discovery scenario where only apo structures of the target are available. This establishes SHAMAN as a robust platform for future drug design endeavors targeting RNA with small molecules, especially considering its potential applicability in virtual screening campaigns. Overall, my research contributed to enhance our understanding and utilization of RNA as a target for small molecule drugs, paving the way for more effective drug design strategies in this evolving field
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Pinheiro, Helano Di?genes. "Redesenho das configura??es estruturais na gest?o universit?ria: a??es derivadas da inova??o e flexibilidade na legisla??o p?s-LDB 1996." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18285.
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Previous issue date: 2011-03-31This paper is set in a scenario in which higher education institutions suffer from external pressure to increase efficiency. The legislation after the Law of Directives and Bases for Education (LDBE), from 1996, is characterized by the fragmentation in its implementation, raising a concern with flexibility and innovation in several normative devices as well as aspects that must be incorporated to its organizational structure. The policies examined in this thesis are: Distance Education (DE); Law of Innovation and the Program of Support to Restructuring and Expansion of Federal Universities (PSREFU). This thesis aims to observe to what extent the characteristics of innovation and flexibility, which mark the new post- LDBE educational legislation, influence the organizational redesign of the Federal University of Cear? (UFC). For being about implementation policies, using contingency approach in order to collect the internal dynamics permeating the redesign of higher education institutions, the thesis focuses on the impacts caused by flexibility and innovation. This is a qualitative research, with case study methods, archive research and semi-structured interviews with members of the university administration. The results don t allow us to confirm the adoption of a more flexible and innovative configuration in the university but it is possible to identify the presence of those elements in the implementation changes, characterizing the hybrid structure. The changes mainly expose the extension of the management of projects to the administrative and academic components related to the institution. In terms of projection, the study found changes in the elements which characterize the current setting and the tendency of the university for adopting a diverse organizational structure. However, if the decentralization of management persists, the academic units may adopt their own structural solutions, but with no evidence of changes in the professional organization in most units. In this perspective, this thesis states that there are difficulties when incorporating innovation and flexibility to their organizational structure, which lead to improvised solutions, superposing skills through the redundancy of structures created with the same purpose or copying exogenous solutions
O trabalho posiciona-se em um cen?rio no qual as institui??es de educa??o superior sofrem press?es externas para o aumento de efici?ncia. A legisla??o ap?s a Lei de Diretrizes e Bases da Educa??o (LDB) de 1996 caracteriza-se pela fragmenta??o na sua implementa??o, traz em v?rios dispositivos normativos a preocupa??o com a flexibilidade e a inova??o, como aspecto a serem incorporadas a estrutura??o organizacional. As pol?ticas em exame nesta tese s?o as de: Educa??o ? Dist?ncia (EAD); Lei de Inova??o e Programa de Apoio a Planos de Reestrutura??o e Expans?o das Universidades Federais (REUNI). A tese objetiva examinar em que medida as caracter?sticas de inova??o e flexibilidade, que balizam a nova legisla??o educacional p?s-LDB, influenciam o redesenho da estrutura organizacional na Universidade Federal do Cear?(UFC). Por tratar-se de pol?ticas em implementa??o utilizando como base te?rica a abordagem contingencial para captar a din?mica interna que permeia o processo de redesenho das organiza??es universit?rias, focando nos impactos relativos ? flexibilidade e inova??o. A pesquisa ? qualitativa, com estrat?gia de estudo de caso, a ado??o de pesquisa documental e entrevistas semi-estruturadas com membros da administra??o da universidade. Os resultados obtidos n?o permitem comprovar a ado??o de uma configura??o mais flex?vel e inovadora na universidade, mas identifica-se a presen?a desses elementos nas mudan?as em implementa??o, o que caracteriza o hibridismo na estrutura. As mudan?as exp?em principalmente a extens?o da gest?o de projetos para o componente administrativo e acad?mico relacionado ?s atividades de ensino da institui??o. Em termos de proje??o, identificaram-se modifica??es nos elementos que caracterizam as configura??es atuais e a tend?ncia da universidade a adotar a estrutura da organiza??o diversificada. No entanto, persistindo o processo de descentraliza??o gerencial, as unidades acad?micas poder?o adotar solu??es estruturais pr?prias, por?m sem evid?ncias de modifica??o na organiza??o profissional na maioria das unidades. Nesta perspectiva, esta tese afirma que existe dificuldades em incorporar a inova??o e a flexibilidade em sua estrutura organizacional gerando solu??es improvisadas, superpondo compet?ncias por duplica??o de estruturas com prop?sitos id?nticos ou copiando solu??es ex?genas
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Fontes, Grazielly dos Anjos. "Novas fronteiras petrol?feras no Brasil : uma an?lise da necessidade de nova regulamenta??o da ?rea do pr?-sal sob a ?tica constitucional." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13911.
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Previous issue date: 2010-09-06The Oil industry in Brazil has gone through several stages during the economical, political and social historical process. However, the significative changes have happened in the last fifteen years, due to market opening arising from the relaxation of the state monopoly over the Oil deposits and its derivatives. The edition of the Constitutional Amendment #9, changing the first paragraph of the 177th item of the Federal Constitution, marked the end of a stiffness about the monopoly that the Brazilian state kept in relation to the exploration and research of Oil and Gas. The economical order was fundamental to actualize the idea contained in the #9 Amendment, since its contents has the power to set up measures to be adopted by public power in order to organize the economical relations from a social viewpoint. The new brazilian Oil scenery, called pre-salt, presents itself in a way to amaze the economical markets, in addition to creating a new perspective to the social sector. This work will identify, in this new scenario, the need for change in the legal system. Nevertheless, this subject must not be treated in a thoughtless way: being an exhaustible good, we shall not forget that the future generations also must benefit from the exploration of natural resources recently discovered. The settlement of a new regulatory mark, including the change in the concession contract model to production and sharing is one of the suggested solutions as a bill in the National Congress, in an attempt to ensure the sovereignty of the nation. The constitutionality of a new regulatory mark is questioned, starting from an analysis of the state monopoly, grounding the comprehnsions in the brazilian constitutions, the relevance of the creation of Petrobras for self-assertion of the state about the monopoly of Oil and derivatives, and its posture after the Constitutional Amendment n? 9 (1995), when a company stops having control of the state monopoly, beginning to compete in a fairly way with other companies. The market opening and private initiative are emphasized from the viewpoint of the Constitutional Principles of the Economical and Social Order. The relaxation of the monopoly regarding the exploratory activity in the Federal Constitution doesn't deprive from the Union the ownerships of underground goods, enabling to this federal entity to contract, directly or by concession of exploration of goods, to state-owned or private companies. The existing oil in the pre-salt layer transforms the scenario from very high risk to low risk, which gives the Union the possibility of defining another way of exploring this resources in the best interests of the Public Administration
A ind?stria do petr?leo no Brasil passou por v?rias etapas durante o processo hist?rico econ?mico, pol?tico e social. Todavia, suas significativas mudan?as ocorreram nos ?ltimos quinze anos, atrav?s da abertura do mercado decorrente da flexibiliza??o do monop?lio estatal sobre as jazidas de petr?leo e seus derivados. A edi??o da Emenda Constitucional n? 9, alterando o par?grafo 1?, do art. 177 da Constitui??o Federal, caracterizou o fim de uma rigidez quanto ao monop?lio que o Estado brasileiro mantinha em rela??o ? pesquisa e explora??o de petr?leo e g?s. A ordem econ?mica foi fundamental para efetivar a id?ia contida na Emenda n? 9, visto que seu conte?do tem o cond?o de estabelecer medidas a serem adotadas pelo poder p?blico a fim de organizar as rela??es econ?micas, sob o vi?s social. O novo cen?rio petrol?fero brasileiro, denominado pr?-sal, apresenta-se de forma a surpreender os mercados econ?micos, al?m de criar uma nova perspectiva para o setor social. O presente trabalho identificar? no novo cen?rio a necessidade de mudan?a do regime jur?dico, todavia, esse assunto n?o pode ser tratado de forma imediatista: como se trata de um bem esgot?vel n?o se deve esquecer que as gera??es futuras tamb?m precisam beneficiar-se da explora??o dos recursos naturais rec?m-descobertos. O estabelecimento de um novo marco regulat?rio, incluindo a mudan?a do modelo de contrato concess?o para produ??o e partilha ? uma das solu??es propostas a n?vel de projeto de lei no Congresso Nacional na tentativa de garantir a soberania da na??o. Questiona-se a constitucionalidade de um novo marco regulat?rio, partindo-se da an?lise do monop?lio estatal, resgatando a compreens?o nas constitui??es brasileiras, a relev?ncia da cria??o da Petrobras para auto-afirma??o do Estado quanto ao monop?lio de petr?leo e derivados, e sua postura ap?s a Emenda Constitucional n? 9 de 1995 quando a empresa deixa de ter o controle do monop?lio estatal, passando a concorrer de forma igualit?ria com outras empresas. Ressalva-se a abertura do mercado e a iniciativa privada sob ?tica dos Princ?pios Constitucionais da Ordem Econ?mica e Social. A flexibiliza??o do monop?lio quanto a atividade explorat?ria na Constitui??o Federal n?o retira da Uni?o a propriedade dos bens do subsolo, possibilitando a este ente federal a contrata??o direta ou atrav?s de concess?o da explora??o do bem a empresas estatais ou privada. O petr?leo existente na camada pr?-sal, transforma um cen?rio de alt?ssimo risco em baixo risco, o que confere a Uni?o a possibilidade de determina??o de outra forma de explorar esses recursos de forma a fazer vale os interesses prim?rio da Administra??o P?blica
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Floro, Elis?ngela Rodrigues. "Trabalho, qualifica??o e precariedade:perspectivas profissionais de egressos do Curso T?cnico em Agropecu?ria do Campus Crato do Instituto Federal do Cear?" Universidade Federal Rural do Rio de Janeiro, 2012. https://tede.ufrrj.br/jspui/handle/jspui/1660.
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The crisis within the accumulation of capital which has been happening to almost four decades in the capitalist countries brought some deeper changes to the manners of production and in the work environment. Technological developments related to the new forms of production organization turned to require a new profile of worker, different from that one who was imposed by rigidity and fragmentation of the Taylor and Ford?s system. Taking into consideration that thechanges in thework areheterogeneous and comprehending that they need to be analyzed in relation to the geographic region and to the productive sector in which they occur, delimited as an object of study the conditions of employment and labor of agricultural technicians who work in the CRAJUBAR Triangle, (it is how is popularly called a specific territory in the region of Cariri in the Southern Cear?). Our aim was to analyze how the productive restructuring process imposed reforms to the educational systems and caused the crisis to agriculture, affecting the new graduates?s procedures and formation trajectories from the Cratocampus of the Instituto Federal do Cear? (IFCE/Crato). It is a basic research of qualitative analysis and descriptive approach in which was used as data collection instruments, the following primary sources: a) internal documents of IFCE Crato (Institutional Development Plan, Institutional Pedagogical Plan, Educational Project Course, school records of recently new graduates ones and subjects guidelines); b) questionnaires applied to teachers, businessmen and landowners; c) transcription of interviews applied to businessmen and rural producers; d) field diary (record of visits to farmers). For a characterization of the agricultural production in the Crajubar Triangle we used statistical data from IPECE and IBGE. The data which were analyzed reveled that the student?s process of technical-professional education of IFCE/Crato were influenced by the conceptions of the School-farm System and by the conventional agriculture, without taking account of studies about family agriculture (the major responsible for agricultural production in the CRAJUBAR Triangle). The chances of employment for the graduates of IFCE/Crato on medium and large range agricultural companies are very rare. The real job opportunities are in the companies of technical assistance and rural extension, which ones that aim to assist farming families to develop a model of agriculture that must be compatible to the semi arid Northeast region. However, the process of technical-professional education in IFCE/Crato is based on the effort to insert technological advances into the production processes of agribusiness. This option, on the detriment of the studies about family farming, distanced the qualification process of students of IFCE/Crato from reality of farming on the CRAJUBAR triangle, revealing the belief in the universality and neutrality of technology as if it could be simply transplanted business model to the family agricultural development model. Nevertheless, this apolitical character of the technical-professional education of IFCE/Crato adds itself to the fact of the main opportunity for integration of graduates to the labor market consist on the offering of temporary work, with flexible relations and poor working conditions offered, by a public company of the Cear? State.
A crise no ac?mulo do capital que vem ocorrendo h? quase quatro d?cadas nos pa?ses capitalistas trouxe profundas mudan?as nos modos de produ??o e no mundo do trabalho. Os avan?os tecnol?gicos relacionados ?s novas formas de organiza??o da produ??o passaram a exigir novo perfil de trabalhador, diferente daquele imposto pela rigidez e fragmenta??o do taylorismo-fordismo. Considerando que as mudan?as no mundo do trabalho s?o heterog?neas e compreendendo que as mesmas precisam ser analisadas em rela??o ? regi?o geogr?fica e ao ramo produtivo em que ocorrem, delimitamos como objeto de estudo as condi??es de emprego e de trabalho de t?cnicos em agropecu?ria que atuam no Tri?ngulo CRAJUBAR, Regi?o do Cariri, no Sul do Estado do Cear?. Nosso objetivo foi analisar como o processo de reestrutura??o produtiva imp?s reformas aos sistemas educacionais e ocasionou a crise na agropecu?ria, afetando as trajet?rias de forma??o e atua??o de egressos do Campus Crato do Instituto Federal do Cear? (IFCE/Crato). Trata-se de uma pesquisa b?sica, de an?lise qualitativa e de car?ter descritivo que utilizou como instrumentos de coleta de dados as seguintes fontes bibliogr?ficas prim?rias: a) documentos internos do IFCE/Crato (Plano de Desenvolvimento Institucional, Plano Pedag?gico Institucional, Projeto Pedag?gico de Curso, registros escolares de alunos egressos e ementas de disciplinas);b) question?rios aplicados aos docentes, empres?rios e propriet?rios rurais; c) transcri??o de entrevistasa empres?rios e produtores rurais; d) di?rio de campo (registro de visitas aos produtores agr?colas). Para uma caracteriza??o da produ??o agr?cola do Tri?ngulo CRAJUBAR, utilizamos dados estat?sticos do IPECE e do IBGE. Os dados analisados revelaram que o processo de forma??o t?cnico-profissional dos alunos do IFCE/Crato foi influenciado pelas concep??es do Sistema Escola-Fazenda e da agricultura convencional, sem contemplar estudos sobre a agricultura familiar (principal respons?vel pela produ??o agr?cola no Tri?ngulo CRAJUBAR). As chances de emprego para egressos do IFCE/Crato em empresas rurais de m?dio e grande porte s?o rar?ssimas. As oportunidades efetivas de trabalho est?o nas empresas de assist?ncia t?cnica e extens?o rural que t?m como objetivo auxiliar as fam?lias rurais a desenvolver um modelo de agricultura compat?vel com o semi?rido nordestino. Por?m, o processo de forma??o t?cnico-profissional no IFCE/Crato est? baseado no esfor?o em inserir avan?os tecnol?gicos nos processos de produ??o do agroneg?cio. Esta op??o, em detrimento dos estudos sobre agricultura familiar, distanciou o processo de qualifica??o dos alunos do IFCE/Crato da realidade da agropecu?ria do Tri?ngulo CRAJUBAR, revelando a cren?a na universalidade e neutralidade da tecnologia como se esta pudesse ser simplesmente transplantada do modelo empresarial para o modelo de desenvolvimento agr?cola familiar. N?o obstante, este car?ter despolitizado da forma??o t?cnico-profissionaldo IFCE/Crato se soma ao fato de a principal oportunidade de inser??o de seus egressos no mercado de trabalho consistir na oferta de trabalho tempor?rio, com rela??es trabalhistasflexibilizadas e condi??es de trabalho precarizadas, por parte de uma empresa p?blica estadual do Cear?.
Book chapters on the topic "RNA flexibility"
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de Schutter, Kristof, Olivier Christiaens, Clauvis Nji Tizi Taning, and Guy Smagghe. "Boosting dsRNA delivery in plant and insect cells with peptide- and polymer-based carriers: case-based current status and future perspectives." In RNAi for plant improvement and protection, 102–16. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0011.
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Abstract Since the discovery of this naturally occurring endogenous regulatory and defence mechanism, RNA interference (RNAi) has been exploited as a powerful tool for functional genomic research. In addition, it has evolved as a promising candidate for a sustainable, specific and ecofriendly strategy for pest management and plant improvement. A key element in this technology is the efficient delivery of dsRNAs into the pest or plant tissues. While several examples using transgenic plants expressing the dsRNAs have proved the potential of this technology, nontransgenic approaches are investigated as alternatives, allowing flexibility and circumventing technical limitations of the transgenic approach. However, the efficacy of environmental RNAi is affected by several barriers, such as extracellular degradation of the dsRNA, inefficient internalization of the dsRNA in the cell and low endosomal escape into the cytoplasm, resulting in variable or low RNAi responses. In the medical field, carrier systems are commonly used to enhance RNA delivery and these systems are being rapidly adopted by the agricultural industry. Using four case studies, this chapter demonstrates the potential of carriers to improve the RNAi response in pest control for aquatic-living mosquito larvae and RNAi-resilient Lepidoptera and to cross the plant cell wall, allowing efficient environmental RNAi in plants.
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de Schutter, Kristof, Olivier Christiaens, Clauvis Nji Tizi Taning, and Guy Smagghe. "Boosting dsRNA delivery in plant and insect cells with peptide- and polymer-based carriers: case-based current status and future perspectives." In RNAi for plant improvement and protection, 102–16. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0102.
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Abstract Since the discovery of this naturally occurring endogenous regulatory and defence mechanism, RNA interference (RNAi) has been exploited as a powerful tool for functional genomic research. In addition, it has evolved as a promising candidate for a sustainable, specific and ecofriendly strategy for pest management and plant improvement. A key element in this technology is the efficient delivery of dsRNAs into the pest or plant tissues. While several examples using transgenic plants expressing the dsRNAs have proved the potential of this technology, nontransgenic approaches are investigated as alternatives, allowing flexibility and circumventing technical limitations of the transgenic approach. However, the efficacy of environmental RNAi is affected by several barriers, such as extracellular degradation of the dsRNA, inefficient internalization of the dsRNA in the cell and low endosomal escape into the cytoplasm, resulting in variable or low RNAi responses. In the medical field, carrier systems are commonly used to enhance RNA delivery and these systems are being rapidly adopted by the agricultural industry. Using four case studies, this chapter demonstrates the potential of carriers to improve the RNAi response in pest control for aquatic-living mosquito larvae and RNAi-resilient Lepidoptera and to cross the plant cell wall, allowing efficient environmental RNAi in plants.
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Ivanyi-Nagy, Roland, Zuzanna Makowska, and Jean-Luc Darlix. "Intrinsic Flexibility of Nucleic Acid Chaperone Proteins from Pathogenic RNA Viruses." In Protein and Peptide Folding, Misfolding, and Non-Folding, 279–306. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118183373.ch10.
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Schuster, Peter, and Peter F. Stadler. "Modeling Conformational Flexibility and Evolution of Structure: RNA as an Example." In Structural Approaches to Sequence Evolution, 3–36. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-35306-5_1.
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Salzberg, Aaron, Punam Mathur, and Peter Dedon. "The Intrinsic Flexibility and Drug-Induced Bending of Calicheamicin DNA Targets." In DNA and RNA Cleavers and Chemotherapy of Cancer and Viral Diseases, 23–36. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-0251-0_2.
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Gaston, Hui Bon Hoa. "Application of NIR Raman Spectroscopy to Probe the Flexibility of RNA Structure." In Methods in Molecular Biology, 149–64. New York, NY: Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0278-2_12.
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Donohue, Christopher. "“A Mountain of Nonsense”? Czech and Slovenian Receptions of Materialism and Vitalism from c. 1860s to the First World War." In History, Philosophy and Theory of the Life Sciences, 67–84. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-12604-8_5.
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AbstractIn general, historians of science and historians of ideas do not focus on critical appraisals of scientific ideas such as vitalism and materialism from Catholic intellectuals in eastern and southeastern Europe, nor is there much comparative work available on how significant European ideas in the life sciences such as materialism and vitalism were understood and received outside of France, Germany, Italy and the UK. Insofar as such treatments are available, they focus on the contributions of nineteenth century vitalism and materialism to later twentieth ideologies, as well as trace the interactions of vitalism and various intersections with the development of genetics and evolutionary biology see Mosse (The culture of Western Europe: the nineteenth and twentieth centuries. Westview Press, Boulder, 1988, Toward the final solution: a history of European racism. Howard Fertig Publisher, New York, 1978; Turda et al., Crafting humans: from genesis to eugenics and beyond. V&R Unipress, Goettingen, 2013). English and American eugenicists (such as William Caleb Saleeby), and scores of others underscored the importance of vitalism to the future science of “eugenics” (Saleeby, The progress of eugenics. Cassell, New York, 1914). Little has been written on materialism qua materialism or vitalism qua vitalism in eastern Europe.The Czech and Slovene cases are interesting for comparison insofar as both had national awakenings in the middle of the nineteenth century which were linguistic and scientific, while also being religious in nature (on the Czech case see David, Realism, tolerance, and liberalism in the Czech National awakening: legacies of the Bohemian reformation. Johns Hopkins University Press, Baltimore, 2010; on the Slovene case see Kann and David, Peoples of the Eastern Habsburg Lands, 1526-1918. University of Washington Press, Washington, 2010). In the case of many Catholic writers writing in Moravia, there are not only slight noticeable differences in word-choice and construction but a greater influence of scholastic Latin, all the more so in the works of nineteenth century Czech priests and bishops.In this case, German, Latin and literary Czech coexisted in the same texts. Thus, the presence of these three languages throws caution on the work on the work of Michael Gordin, who argues that scientific language went from Latin to German to vernacular. In Czech, Slovenian and Croatian cases, all three coexisted quite happily until the First World War, with the decades from the 1840s to the 1880s being particularly suited to linguistic flexibility, where oftentimes writers would put in parentheses a Latin or German word to make the meaning clear to the audience. Note however that these multiple paraphrases were often polemical in the case of discussions of materialism and vitalism.In Slovenia Čas (Time or The Times) ran from 1907 to 1942, running under the muscular editorship of Fr. Aleš Ušeničnik (1868–1952) devoted hundreds of pages often penned by Ušeničnik himself or his close collaborators to wide-ranging discussions of vitalism, materialism and its implied social and societal consequences. Like their Czech counterparts Fr. Matěj Procházka (1811–1889) and Fr. Antonín LenzMaterialismMechanismDynamism (1829–1901), materialism was often conjoined with "pantheism" and immorality. In both the Czech and the Slovene cases, materialism was viewed as a deep theological problem, as it made the Catholic account of the transformation of the Eucharistic sacrifice into the real presence untenable. In the Czech case, materialism was often conjoined with “bestiality” (bestialnost) and radical politics, especially agrarianism, while in the case of Ušeničnik and Slovene writers, materialism was conjoined with “parliamentarianism” and “democracy.” There is too an unexamined dialogue on vitalism, materialism and pan-Slavism which needs to be explored.Writing in 1914 in a review of O bistvu življenja (Concerning the essence of life) by the controversial Croatian biologist Boris Zarnik) Ušeničnik underscored that vitalism was an speculative outlook because it left the field of positive science and entered the speculative realm of philosophy. Ušeničnik writes that it was “Too bad” that Zarnik “tackles” the question of vitalism, as his zoological opinions are interesting but his philosophy was not “successful”. Ušeničnik concluded that vitalism was a rather old idea, which belonged more to the realm of philosophy and Thomistic theology then biology. It nonetheless seemed to provide a solution for the particular characteristics of life, especially its individuality. It was certainly preferable to all the dangers that materialism presented. Likewise in the Czech case, Emmanuel Radl (1873–1942) spent much of his life extolling the virtues of vitalism, up until his death in home confinement during the Nazi Protectorate. Vitalism too became bound up in the late nineteenth century rediscovery of early modern philosophy, which became an essential part of the development of new scientific consciousness and linguistic awareness right before the First World War in the Czech lands. Thus, by comparing the reception of these ideas together in two countries separated by ‘nationality’ but bounded by religion and active engagement with French and German ideas (especially Driesch), we can reconstruct not only receptions of vitalism and materialism, but articulate their political and theological valances.
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Tabler, Martin, and Georg Sczakiel. "Catalytic Antisense RNA Based on Hammerhead Ribozymes." In Antisense Technology, 93–126. Oxford University PressOxford, 1997. http://dx.doi.org/10.1093/oso/9780199635832.003.0005.
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Abstract Some plant viruses are accompanied by so-called satellite RNAs which cannot replicate autonomously but require a helper virus for replication (1). Some of these satellite RNAs, especially the circular satellite RNAs, which are also called virusoids, undergo Mg2 catalysed autocatalytic self-cleavage at a defined position of their RNA genome. A specific phosphodiester bond is chemically cleaved in an intramolecular trans-esterification reaction resulting in a 2’ ,3’ cyclic phosphate located 5’ to the cleavage site, whereas the 3’ cleavage product has a 5’ hydroxyl group. A similar type of reaction can be found in two plant viroids which, unlike the satellite RNAs, do not depend on the presence of a helper virus for replication, and in the RNA transcript of a satellite DNA 2 of newt. A feature common to all these RNAs is the presence of a so-called ‘hammerhead structure’ (2).” The hammerhead structure consists of several conserved nucleotides and three helices that can he drawn such that the resulting secondary structure resembles the head of a carpenter’s hammer. A generally accepted numbering system has been defined (4) which can be seen in Figure 1. Despite the generality of the hammerhead structure and the conservation of the nucleotides that are involved in catalysis, there is considerable flexibility with regard to loop size and length of the helices.
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Dock-Bregeon, A. C., and D. Moras. "Nucleic Acids and Their Complexes." In Crystallization of Nucleic Acids and Proteins. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780199636792.003.0012.
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At first glance crystallizing nucleic acids poses the same problems as crystallizing proteins since most of the variables to investigate are alike. It is thus astonishing that crystallization data banks (1) that describe so many successful protein crystallizations are so poor in information on nucleic acids. This relies on the physico-chemical and biochemical characteristics of nucleic acids distinguishing them from proteins. The aim of this chapter is to underline features explaining the difficulties often encountered in nucleic acid crystallization and to discuss strategies that could help to crystallize them more readily, either as free molecules or as complexes with proteins. Other general principles, in particular for RNA crystallization, are discussed in ref. 2. Among natural nucleic acids only the smaller ones provide good candidates for successful crystallizations. Large DNAs or RNAs can a priori be excluded because of their flexibility that generates conformational heterogeneity not compatible with crystallization. Thus the smaller RNAs with more compact structures (with 75-120 nt), especially transfer RNAs (tRNAs), but also 5S RNA, were the first natural nucleic acids to be crystallized (3, 4). At present attempts are being made with other RNA systems, such as ribozymes and introns, fragments of mRNA, viroids, viral and other tRNA-like RNAs, SELEX-evolved RNAs, and crystallization successes leading to X-ray structure determinations were reported for RNA domains of up to 160 nt long, with the resolution of the P4-P6 domain of the self-splicing Tetrahymena intron (5). The recent excitement in nucleic acid crystallography, and particularly in RNA crystallography, have partly been due to technological improvements in the preparation methods of the molecules. Advances in oligonucleotide chemical synthesis provide opportunity for making large amounts of pure desoxyribo- and more recently of ribo-oligomers of any desired sequence. This led to the crystallization of a number of DNA and RNA fragments and was followed by the co-crystallization of complexes between proteins and such synthetic fragments. Transcription methods of RNAs from synthetic DNA templates were also essential for rejuvenating the structural biology of RNAs. In the case of complexes of proteins with RNAs, the main difficulty was to purify large quantities of homogeneous biological material with well defined physico-chemical properties.
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Shafaati, Maryam, Mohammadreza Salehi, and Maryam Zare. "Revolutionizing HCV Therapy: microRNA Approaches in New Era of Treatment." In Liver Cancer - Multidisciplinary Approach [Working Title]. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1005068.
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Since the development and evolution of COVID-19 immunization, the use of mRNA-based technologies has led to revolutionary changes due to the potential of RNA-based therapies, which are believed to be useful in treating many infectious diseases. Information on the treatment of hepatitis C virus (HCV) following this rule highlights the potential therapeutic use of microRNAs (miRNAs). The advent of direct-acting antivirals (DAAs) has changed the paradigm of HCV treatment. However, challenges remain, particularly in the areas of viral resistance, genetic diversity, and chronic diseases. Among these, miRNAs are a sensible approach to complementing and improving existing models. The implementation of new non-coding RNAs should be investigated. This chapter discusses the potential and public awareness of non-coding RNA (ncRNA) strategies against HCV. From the modification of miRNAs to the discovery of non-coding RNA pathways and focusing on their applications, efficacy, and therapeutic potential in HCV. As the scientific community looks toward the development of antiviral drugs, this chapter demonstrates that the introduction of non-coding RNA drugs into existing health systems holds promise for addressing and providing solutions to challenges such as drug resistance, viral persistence, and more. New non-coding RNAs in HCV therapy not only expand the scope of treatment but also define the therapeutic landscape and increase flexibility and adaptability in the face of HCV challenges.
Conference papers on the topic "RNA flexibility"
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Phan, John H., Po-Yen Wu, and May D. Wang. "Improving the flexibility of RNA-Seq data analysis pipelines." In 2012 IEEE International Workshop on Genomic Signal Processing and Statistics (GENSIPS). IEEE, 2012. http://dx.doi.org/10.1109/gensips.2012.6507729.
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Xie, Qihui, and Michel-Alexandre Cardin. "A Framework for Designing and Managing Flexibility and Real Options in Engineering Systems Based on Decision Rules." In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/detc2017-67042.
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This paper introduces a framework to design and manage flexibility in engineering systems based on the concept of decision rules. A decision rule can be described as a heuristic triggering mechanism that is used to determine when it is appropriate to exercise flexibility in systems operations. The proposed framework differs from existing real options analysis (ROA) approaches used in a design and management setting by focusing on the practicability in the implementation phase of engineering systems. By incorporating decision rules in the design process, this framework not only helps generate better performing designs, it also provides intuitive guidance for decision makers (DMs) to manage the system in operations. The proposed framework is applied as demonstration to the design and management of an anaerobic digestion (AD) waste-to-energy (WTE) plant. It demonstrates significant lifecycle performance improvement as compared to a standard design analysis. A comparison with existing ROA approaches shows that another advantage of the proposed framework is the ability to analyze systems facing multiple uncertainty sources and relying on multiple flexibility strategies as a way to improve expected lifecycle performance.
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Jin, Xiaoning, and Jun Ni. "Dynamic Strategies for Preventive Maintenance Scheduling With Throughput Target Variation." In ASME 2012 International Manufacturing Science and Engineering Conference collocated with the 40th North American Manufacturing Research Conference and in participation with the International Conference on Tribology Materials and Processing. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/msec2012-7384.
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This paper considers a period-review production and preventive maintenance (PM) scheduling problem for manufacturing systems subject to uncertain demand in a finite-horizon. We consider multiple levels of PM which provide the system with flexibility of choosing various types of PM to be adaptive to the throughput target. A model with PM flexibility is proposed to simultaneously determine optimal production quantity and PM level for a single-product manufacturing system. A real option analysis (ROA) is applied to quantify the benefit of PM flexibility so that it can be considered in a cost function. The optimal strategy for a joint maintenance and production system that maximizes the overall expected profit of the system is obtained by a stochastic dynamic programming approach. Results are supported by numerical examples and show the comparison between the proposed PM-flexible model and the conventional PM planning model with single and fixed PM type. Managerial insights are provided on making adaptive PM and production decisions by trading off revenue and costs of corrective actions in different manufacturing applications.
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Peel, Larry D., and Charles Ball. "Fabrication and Testing of a Simple “Bionic Arm” Demonstrator." In ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2010. http://dx.doi.org/10.1115/smasis2010-3658.
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Artificial or “bionic” limbs have been the subject of considerable research, TV shows, and dreams by children. The “Six Million Dollar Man” show was about a man who received artificial limbs after his own were lost in an accident. To get students interested in practical engineering, the current work showcases a simple artificial arm that produces greater force than a typical man, demonstrates the capability of Rubber Muscle Actuators (RMA), and provides a portable “arm wrestling platform” for student recruitment efforts. The actuators for “Kingsville Arm One & Two” are McKibben-like actuators made from fiber-reinforced elastomeric composites. These actuators offer excellent strength-to-weight ratios and contract similar to a human muscle. RMAs produce greater force and have less “blow-outs” than typical McKibben actuators because of optimized braid angles and ends that transfer loads through the braid fibers. Kingsville Arm One (KA1) was developed in just two weeks. It consisted of carbon/fiberglass/epoxy composite tubular bones, a metal clevis “elbow” and four RMAs. With considerable effort, a very large student was able to overcome the force generated in an “arm wrestling” contest. KA1’s actuators had end attachments that transferred loads well and enabled flexibility, but easily tore and had air leaks. Kingsville Arm Two (KA2) had new “bones” and RMAs. Although slightly smaller diameters, the KA2 RMAs produced comparable forces to the KA1 RMAs and had molded end attachments. The rigid ends did not allow as much rotation as expected and necessitated using just 2 RMAs. With only two RMAs, KA2 produced approximately the same “arm strength” as KA1. Future work will focus on flexible but durable RMA molded ends, life-like skins and a realistic “hand.”
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La¨uferts, Ulrike, Charlotte Halbe, and Aliki van Heek. "Value-Creating Investment Strategies to Manage Risk From Structural Market Uncertainties: Switching and Compound Options in (V)HTR Technologies." In Fourth International Topical Meeting on High Temperature Reactor Technology. ASMEDC, 2008. http://dx.doi.org/10.1115/htr2008-58157.
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To measure the value of a technology investment under uncertainty with standard techniques like net present value (NPV) or return on investment (ROI) will often uncover the difficulty to present convincing business case. Projected cash flows are inefficient or the discount rate chosen to compensate for the risk is so high, that it is disagreeable to the investor’s requirements. Decision making and feasibility studies have to look beyond traditional analysis to reveal the strategic value of a technology investment. Here, a Real Option Analysis (ROA) offers a powerful alternative to standard discounted cash-flow (DCF) methodology by risk-adjusting the cash flow along the decision path rather than risk adjusting the discount rate. Within the GEN IV initiative attention is brought not only towards better sustainability, but also to broader industrial application and improved financing. Especially the HTR design is full of strategic optionalities: The high temperature output facilitates penetration into other non-electricity energy markets like industrial process heat applications and the hydrogen market. The flexibility to switch output in markets with multi-source uncertainties reduces downside risk and creates an additional value of over 50% with regard to the Net Present Value without flexibility. The supplement value of deploying a modular (V)HTR design adds over 100% to the project value using real option evaluation tools. Focus of this paper was to quantify the strategic value that comes along a) with the modular design; a design that offers managerial flexibility adapting a step-by-step investment strategy to the actual market demand and b) with the option to switch between two modes of operation, namely electricity and hydrogen production. We will demonstrate that the effect of uncertain electricity prices can be dampened down with a modular HTR design. By using a real option approach, we view the project as a series of compound options — each option depending on the exercise of those that preceded it. At each end of the design phase, the viability will be reviewed conditional on the operating spread at each time step. We quantify the value of being able to wait with the investment into a next block until market conditions are favourable and to be able to abandon one block if market conditions are disapproving. To derive the intrinsic value of this multi block HTR design, it will be compared with a reference investment of a full commitment light water reactor without any managerial flexibility. In another case, we raise the question to what extent product output diversification is a suitable strategy to cope with long term market uncertainty in electricity price. What is the value of a multi-potent technology that is able to produce output for energy markets others than the electricity market? To investigate this, we concentrate on The Netherlands, a country with an intense industrial demand in electricity and hydrogen.
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Shirkhodaie, Amir, Julian Blair, and Kemba Heard. "Failure Diagnosis in Rotory Dynamic Systems Based on Finite Element Prediction Model." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42501.
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Machinery such as steam turbines, compressors, and generators are rotating machines. Over the years these machines have become very complex, due to the increased need for higher speed rotating machinery. Overtime these machines develop excessive dynamic stresses if they are ran at speeds near to their natural frequencies or under abnormal operating conditions. Many technological advances in the aerospace and automotive industries can be held accountable for these faster speeds. Currently, machinery diagnostics is being used to monitor rotating machinery and determine their condition while in operation. To determine how a system will behave under certain operation conditions, a physics-based model of the system can be modeled and analyzed using finite element analysis. These results will provide stress, deformation, flexibility, stiffness, and vibration characteristics of the system. These results can show where the critical points are on the system and how the system’s load is distributed. By using finite element techniques engineers can simulate the behavior of the system under different loading conditions, which can justify the selection of a particular design alternative, and ultimately save time and money. This paper discusses our technical approach used to develop a physics-based model of a rotor dynamic system and discusses results of this research effort.
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Fu, Xin, and Huayong Yang. "Development of an Anti-Interference Swirl Meter Based on Numerical Simulation of Hydrodynamic Vibration." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2095.
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Abstract Having the advantages of no motion elements, high reliability, undemanding maintenance and good medium flexibility, the swirl meter has been widely used to measure the gas, liquid and steam in chemical, petroleum as well as processing industries. For the current one-piezoelectric-pressure-sensor swirl meter, however, the measuring error caused by the interference pressure oscillation limits its application in the system where pressure is unsteady, or a noisemaker is nearby. In this paper, the fluid dynamic features inside the channel of the swirl meter are studied numerically and by experiment. The time dependent vortex motions as well as the hydrodynamic vibrations within the channel of the swirl meter are simulated using the CFD approaches of the RNG k-ε model. The computed flow fields indicate that the eccentric motion of vortexes initiates an axisymmetric pressure oscillation within the vortex precession area of the swirl meter. The frequency of the oscillation shifts linearly with volume flow rates. Both the calculated and the measured results prove that the hydrodynamic vibrations on the arbitrary axisymmetric points are equal in amplitude and frequency but with a 180 degree phase difference. By installing differential pressure transducers on such the axisymmetric points, the signals of the vortex pressure oscillations are enhanced, while the interferential signals are suppressed, enabling the anti-interference performance and low-flowrate sensibility of the swirmeter to be effectively improved.
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Mosoiu, Ovidiu, Catalin Cioaca, and Ion Balaceanu. "USING THE CAPITAL ASSET PRICING MODEL IN INFORMATION SECURITY INVESTMENTS." In eLSE 2018. Carol I National Defence University Publishing House, 2018. http://dx.doi.org/10.12753/2066-026x-18-220.
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Interest in real option theory has intensified over the last decade due to the high uncertainty faced by some private and public organizations when deciding to make a strategic investment (competitive environment) or when faced with an external requirement of the organizational environment (ensuring security standards). Traditional methods of investment analysis define the existence of investment opportunity by net present value (NPV), ignoring the possibility that an investment will start from a certain moment in the future. In this way, it is not possible to capture the phenomenon in dynamics, which leads to limiting the possibility of solving the existing uncertainty over the time regarding the optimal use of resources. The need to optimize managerial strategies and give some flexibility to decision-makers in relation to the changes in the organization's external environment has triggered the real options analysis (ROA). By using ROA, a win-win situation is created in which the available policy options mitigate uncertainty fluctuations of updated net worth (based on new information available) and, at the same time, by applying the best strategy, maximize earnings. Information security systems are designed on a layered architecture and the decision to improve performance on each layer is the responsibility of strategic management. Being a modular system, it is recommended to build the architecture by stages, depending on the value of the assets. Also, the relatively long duration and costs of implementation, limited resources, irreversible character, and project risks determine the value and evaluation of the investment, involving its representation as a combined option associated with a succession of decisions. The proposed model is inspired from the theory of financial and real options, but also from the fuzzy logic. This approach seeks to anchor specific mechanisms for the study of asymmetric risk events in the security market (perfect market assumptions are of course limiting but provide a quick overview, which is essential for the proposed application). Using the capital asset pricing model (CAPM), the return on investments in the security of IT & C systems, by reference to the investment risk as the estimated value, is defined. Investors can take risks that can be broken down into two components: systematic risks and non-systemic risks. Systematic risk refers to the variability of income caused by external factors (macroeconomic conditions), being a measure of the relative market volatility of relative incomes. Unsystematic risk refers to income variability caused by unpredictable factors (mismanagement decisions, abrupt technologies overtaken). The depreciation of security investments is inherent and leads to the dilemma of small and frequent investments or major and rare investments. On this issue, the proposed model can provide solutions to decision-makers. Uncertainty, irreversibility, growth potential and competition are factors that influence the behavior and investment decision. We consider that by using the capital asset pricing model in the security investments associated with eLerning training systems, we can increase the precision of optimal investment in terms of risk and opportunity balancing.
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Omeke, James, and Albertus Retnanto. "Advances in Virtual Flow Metering Using Deep Composite Lstm-Autoencoder Network for Gas-Condensate Wells." In Middle East Oil, Gas and Geosciences Show. SPE, 2023. http://dx.doi.org/10.2118/213614-ms.
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Abstract In terms of cost and execution time, data-driven Virtual Flow Meters (VFM) are alternative solutions to traditional well testing (WT) and physical multiphase flow meters (MPFM) for production rate determination which is needed for critical decisions by operators but faced with the challenge of low accuracy due to the transient and dynamic state of multiphase flow systems. Recently, some progress has been recorded by training steady-state feed-forward neural networks to learn to approximate production rate based on a certain number of input features (e.g., choke opening, pressure, temperature, etc.) without any recursive feedback connection between the network outputs and inputs. This disconnection has impacted their accuracy. Dynamic artificial neural network, for example, the recurrent neural networks (RNN), e.g., LSTM has shown good performance as their architecture allows for the usage of data from the past time step to predict the current time step. Forecast accuracy for RNNs is limited to a short period due to their inherent vanishing gradient issues. While a majority of VFM applications have been developed for oil and gas systems, little or non is applied to gas condensate systems. In this project, a sequence-to-sequence deep composite LSTM-Autoencoders neural network (LSTM-A-NN) was explored and used to demonstrate the ability to leverage its architecture to accurately predict multiphase flow rate for highly dynamic multiphase flow phenomenon associated with retrograde condensate reservoirs. Data used in training and validating the LSTM-A-NN were generated from simulations. First, a 3D compositional simulator (ECLIPSE 300) was used to simulate, as close as possible, a realistic case of a compositional reservoir with flow from the subsurface to the wellhead to generate production rate data. Secondly, an integrated production system was built using GAP to simulate a coupled material-balanced-based inflow with wells and a surface separator. The production output data in this case includes production rates, wellhead pressure, bottom-hole pressure, temperatures, condensate-gas ratio, etc. For both cases, the LSTM-A-NN performance was impressive (mean square error less than 1) and demonstrated its flexibility and scalability with an increasing number of input features (production data). The LSTM-A-NN learns the physics of complex fluid flow through non-linear dimensionality reduction while passing the temporal sequence of production data through its encoder network. The encoded data representation is thereafter decoded and reconstructed such that the output is in the same dimension as the input. The ability to leverage some advanced artificial intelligence frameworks such as a composite LSTM-A-NN has proven that it is possible to achieve the desired accuracy needed in data-driven VFM to meet the requirement of low cost, low execution time, and high accuracy. This project has also demonstrated the ability of the data-driven model to learn the complex dynamics within the temporal ordering of input sequences of production data, with an internal memory adapted to remember or use information across long input sequences, hence, yielding longer and more reliable forecasts, unlike other networks.
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Schilberg, Daniel, Jelena Borovica, Lea Vianden, Meiko Litzba, and Florian Millmann. "Robots in Popular Sciences Compared with their Real Capabilities." In 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1002316.
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In this paper, statements from popular science sources are contrasted with data from primary science articles and studies. It is observed to what extent the opinions and statements of the popular science articles differ from the studies and scientific articles in terms of ethics and acceptance. For this purpose, the field is divided into 4 fields, which are processed independently.To begin with, the industrial robots are examined. These are used in the area of production as well as in the area of maintenance and repair. These robots are able to learn from each other and to work with each other and with humans. Even a tire change can be carried out by an industrial robot today. Likewise, new developments offer construction spaces that are difficult for humans to access. Activities that do not serve industrial production, but rather the performance of services for people and facilities, are carried out by service robots. They are freely programmable motion devices that perform services partially or fully automatically and are used in the areas of care, gastronomy, tourism, as well as private households. In the future, skills such as flexibility and judgment must be perfected. The use of some service robots is already safe for humans. Similar to service robots, social robotics also focuses on interaction between humans and robots. These are sensorimotor robots that can communicate with humans in a social manner. In doing so, they can build social relationships and constantly learn. The social robots are usually in a human-like (humanoid) or animal-like (animaloid) body, but can also be used merely as software. Examples for application are care, therapy and entertainment robots. In addition to the three physical robots, software robots (software bots) are virtual robots used for process automation. They are the result of the application of Robotic Process Automation (RPA), which includes various approaches and technologies. They are used in almost every industry. In the following paper, the applications of softwarebots in finance, healthcare, public administration, and law are examined. Only minor discrepancies between the secondary literature studied and the state of the art can be observed in the texts examined.For the industrial robots, no deviations from statements from popular science sources can be found. In the secondary literature, however, these are not found as frequently as the other robot types studied. This is probably since the interested parties tend to be companies that are advertised through other channels. Nevertheless, some publications can be found for the manufacturing and maintenance and repair sectors. The largest application area today is still manufacturing. However, current robot developments offer promising and potential benefits for the maintenance and repair of industrial plants. In comparison, the research on service robots have shown that a variety of characteristics and capabilities are attributed to them in the secondary literature, most of which are consistent with the status quo of service robotics. In the next area examined, social robotics, the claims from the secondary literature, as with the previous robot types, deviate little from the primary scientific facts. In the technical area, the claims of the secondary literature are fundamentally true, although the ability of robots is generalized in some aspects. Softawarebots, on the other hand, are partially distinct from the previously mentioned robots. Especially the terms used for software applications as software bots in popular science articles do not refer to scientific classifications.
Reports on the topic "RNA flexibility"
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Bloch, G., and H. S. Woodard. regulation of size related division of labor in a key pollinator and its impact on crop pollination efficacy. Israel: United States-Israel Binational Agricultural Research and Development Fund, 2021. http://dx.doi.org/10.32747/2021.8134168.bard.
Full textAbstract:
Despite the rapid increase in reliance on bumble bees for food production and security, there are many critical knowledge gaps in our understanding of bumble bee biology that limit their colony production, commercial management, and pollination services. Our project focuses on the social, endocrine, and molecular processes regulating body size in the two bumble bee species most important to agriculture: Bombus terrestris in Israel, and B. impatiens in the USA. Variation in body size underline both caste (queen/worker) differentiation and division of labor among workers (foragers are typically larger than nest bees), two hallmarks of insect sociality which are also crucial for the commercial rearing and crop pollination services of bumble bees. Our project has generated several fundamental new insights into the biology of bumble bees, which can be integrated into science-based management strategies for commercial pollination. Using transcriptomic and behavioral approaches we show that in spite of high flexibility, task performance (brood care or foraging) in bumble bee colonies is associated with physiological variation and differential brain gene expression and RNA editing patterns. We further showed that interactions between the brood, the queen, and the workers determine the developmental program of the larva. We identified two important periods. The first is a critical period during the first few days after hatching. Larvae fed by queens during this period develop over less days, are not likely to develop into gynes, and commonly reach a smaller ultimate body size compared to workers reared mostly or solely by workers. The facial exocrine (mandibular and hypopharangeal) glands are involved in this queen effect on larva development. The second period is important for determining the ultimate body size which is positively regulated by the number of tending workers. The presence of the queen during this stage has little, if at all, influence. We further show that stressors such as agrochemicals that interfere with foraging or brood care specific processes can compromise bumble bee colony development and their pollination performance. We also developed new technology (an RFID system) for automated collection of foraging trip data, for future deployment in agroecosystems. In spite of many similarities, our findings suggest important differences between the Eurasian model species (B. terrestris) and the North American model species (B. impatiens) that impact how management strategies translate across the two species. For example, there is a similar influence of the queen on offspring body size in both species, but this effect does not appear to be mediated by development time in B. impatiens as it is in B. terrestris. Taken together, our collaboration highlights the power of comparative work, to show that considerable differences that exist between these two key pollinator species, and in the organization of young bumble bee nests (wherein queens provide the majority of care and then transition away from brood care) relative to later stages of nest development.
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Gelb, Jr., Jack, Yoram Weisman, Brian Ladman, and Rosie Meir. Identification of Avian Infectious Brochitis Virus Variant Serotypes and Subtypes by PCR Product Cycle Sequencing for the Rational Selection of Effective Vaccines. United States Department of Agriculture, December 2003. http://dx.doi.org/10.32747/2003.7586470.bard.
Full textAbstract:
Objectives 1. Determine the serotypic identities of 40 recent IBV isolates from commercial chickens raised in the USA and Israel. 2. Sequence all IBV field isolates using PCR product cycle sequencing and analyze their S 1 sequence to detennine their homology to other strains in the Genbank and EMBL databases. 3. Select vaccinal strains with the highest S 1 sequence homology to the field isolates and perform challenge of immunity studies in chickens in laboratory trials to detennine level of protection afforded by the vaccines. Background Infectious bronchitis (IB) is a common, economically important disease of the chicken. IB occurs as a respiratory form, associated with airsacculitis, condemnation, and mortality of meat-type broilers, a reproductive form responsible for egg production losses in layers and breeders, and a renal form causing high mortality in broilers and pullets. The causative agent is avian coronavirus infectious bronchitis virus (IBV). Replication of the virus' RNA genome is error-prone and mutations commonly result. A major target for mutation is the gene encoding the spike (S) envelope protein used by the virus to attach and infect the host cell. Mutations in the S gene result in antigenic changes that can lead to the emergence of variant serotypes. The S gene is able to tolerate numerous mutations without compromising the virus' ability to replicate and cause disease. An end result of the virus' "flexibility" is that many strains of IBV are capable of existing in nature. Once formed, new mutant strains, often referred to as variants, are soon subjected to immunological selection so that only the most antigenically novel variants survive in poultry populations. Many novel antigenic variant serotypes and genotypes have been isolated from commercial poultry flocks. Identification of the field isolates of IBV responsible for outbreaks is critical for selecting the appropriate strain(s) for vaccination. Reverse transcriptase polymerase chain reaction (RT-PCR) of the Sl subunit of the envelope spike glycoprotein gene has been a common method used to identify field strains, replacing other time-consuming or less precise tests. Two PCR approaches have been used for identification, restriction fragment length polymorphism (RFLP) and direct automated cycle sequence analysis of a diagnostically relevant hypervariab1e region were compared in our BARD research. Vaccination for IB, although practiced routinely in commercial flocks, is often not protective. Field isolates responsible for outbreaks may be unrelated to the strain(s) used in the vaccination program. However, vaccines may provide varying degrees of cross- protection vs. unrelated field strains so vaccination studies should be performed. Conclusions RFLP and S1 sequence analysis methods were successfully performed using the field isolates from the USA and Israel. Importantly, the S1 sequence analysis method enabled a direct comparison of the genotypes of the field strains by aligning them to sequences in public databases e.g. GenBank. Novel S1 gene sequences were identified in both USA and Israel IBVs but greater diversity was observed in the field isolates from the USA. One novel genotype, characterized in this project, Israel/720/99, is currently being considered for development as an inactivated vaccine. Vaccination with IBV strains in the US (Massachusetts, Arkansas, Delaware 072) or in Israel (Massachusetts, Holland strain) provided higher degrees of cross-protection vs. homologous than heterologous strain challenge. In many cases however, vaccination with two strains (only studies with US strains) produced reasonable cross-protection against heterologous field isolate challenge. Implications S1 sequence analysis provides numerical similarity values and phylogenetic information that can be useful, although by no means conclusive, in developing vaccine control strategies. Identification of many novel S1 genotypes of IBV in the USA is evidence that commercial flocks will be challenged today and in the future with strains unrelated to vaccines. In Israel, monitoring flocks for novel IBV field isolates should continue given the identification of Israel/720/99, and perhaps others in the future. Strains selected for vaccination of commercial flocks should induce cross- protection against unrelated genotypes. Using diverse genotypes for vaccination may result in immunity against unrelated field strains.