Alergenos: relación entre función biológica y alergenicidad

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Homero San Juan

1998-03-01

Full Text Available Los alergenos se encuentran en muy diversas fuentes, pero, tienen la particularidad de inducir la producción de inmunoglobulina E (IgE y provocar alergia. No se conoce una característica molecular biológica común entre los alergenos que explique su capacidad alergénica. En los últimos años, se han demostrado o inferido diferentes funciones biológicas en los alergenos, generando nuevas hipótesis sobre el papel de dichas funciones en la actividad alergénica. Con el fin de identificar qué funciones biológicas se han demostrado o inferido en los alergenos y analizar su posible influencia en el papel alergénico, se revisaron aproximadamente doscientos alergenos teniendo como base los ya caracterizados por el Comité de Nomenclatura de Alergenos de la OMS, como también otros menos caracterizados pero con algunas propiedades fisicoquímicas conocidas. Los alergenos se agruparon de acuerdo con la actividad biológica y se tabularon con su fuente de origen, peso molecular (PM, punto isoeléctrico (pl, frecuencia de reactividad en la población alérgica, potenciales sitios de glicosilación y formación de enlaces disulfuro. Se identificaron 88 alergenos en los que se ha informado alguna actividad biológica. El agrupamiento de estos según la actividad produjo los siguientes resultados: enzimática (47,2%, inhibición de enzimas (11,3%, transporte (18,1%, regulación de la actividad celular (15,9% y otras actividades como la de conferir resistencia a enfermedades en plantas y citólisis (7,9%. En muchos de estos alergenos, la actividad biológica ha sido inferida por su homología estructural con proteínas de función conocida, pero los experimentos que corroboren dicha función no se han realizado. La mayoría de estos alergenos tienen en común PM

Evolution of DOI Usage and Registration

Science.gov (United States)

James, N.; Wanchoo, L.

2017-12-01

NASA's Earth Science Data and Information System (ESDIS) Project has implemented an automated system for assigning Digital Object Identifiers (DOIs) to Earth Science data products being managed by its network of 12 distributed active archive centers (DAACs). Using the ESDIS DOI system, over 3000 DOIs have been assigned, registered, and made publicly accessible while over 1000 assigned DOIs are being held in reserve until ready for public use. The goal is to assign a DOI to each of the 8000+ data collections under ESDIS management. DOIs make it easier for researchers to discover and use earth science data and they enable users to provide valid citations for the data they use in research. Also for the researcher wishing to reproduce the results presented in science publications, the DOI can be used to locate the exact data or data products being cited. ESDIS DOIs also provide data "Provenance" which is information about the creation and history of the data in question. This would include when the data was collected, which instrument was used to collect the data, and the version of the product at the time the DOI was assigned. Over the past few years, requests for DOIs have increased significantly as DAACs assign DOIs to both legacy data from earlier missions and new data products from in-orbit missions. This study will evaluate the evolution of DOI registration and its usage over those years comparing data products as they are organized by mission, science discipline and data product level. It is hoped that the study results will help NASA determine how to prioritize future products for DOI assignment and inform future studies that would identify trends over time of increased use of data citations resulting in increased discovery and distribution of NASA Earth science data products.

Flavonoides em Annonaceae: ocorrência e propriedades biológicas

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Clara dos Reis Nunes

2012-05-01

Full Text Available Esta revisão descreve algumas propriedades biológicas e químicas, bem como os usos etnobotânicos e farmacológicos de algumas substâncias isoladas a partir do gênero Annona (família Annonaceae. As espécies dessa família possuem distribuição tropical e subtropical. A Annona muricata L., em especial, possui proeminência na economia de frutos tropicais, além de ser quimicamente caracterizada pela presença de substâncias fenólicas e terpênicas. Logo, este trabalho destaca a importância e ocorrência desses metabólitos, bem como suas atividades biológicas.

Efeito da solarização sobre propriedades físicas, químicas e biológicas de solos

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R. Ghini

2003-02-01

Full Text Available A solarização é um método de desinfestação que consiste na cobertura do solo com um filme de polietileno transparente, durante o período de intensa radiação solar, e atua por meio do aumento da temperatura do solo. Quatro ensaios foram realizados no estado de São Paulo, nos municípios de Mogi das Cruzes, Jarinu, Piracicaba e Itatiba, nos anos de 2000 e 2001, com o objetivo de avaliar os efeitos da solarização nas propriedades físicas, químicas e biológicas dos solos. A solarização reduziu significativamente a resistência à penetração dos solos nos ensaios de Jarinu, Piracicaba e Itatiba. Em Jarinu, oito meses após a retirada do plástico, as diferenças entre os tratamentos permaneceram. Por outro lado, em Mogi das Cruzes, onde o ensaio foi instalado em solo turfoso, a solarização causou aumento na resistência na camada de 2,5 a 5 cm de profundidade. Nos ensaios de Piracicaba e Jarinu, foram feitas avaliações de macro, microporosidade, porosidade total e densidade, não tendo os tratamentos diferido entre si, porém houve uma tendência de redução na densidade dos solos solarizados. A atividade microbiana, avaliada pela hidrólise de diacetato de fluoresceína, foi reduzida pela solarização. A supressividade a Fusarium oxysporum f. sp. phaseoli foi avaliada in vitro, pela colonização de amostras de solo usando um isolado marcado com resistência a benomyl, no ensaio de Mogi das Cruzes. A solarização reduziu a recuperação do patógeno, evidenciando um aumento da supressividade. Nos solos solarizados, houve aumento significativo dos teores de N-NH4+ em todos os experimentos, Mn em três, N-NO3-, Mg2+ e saturação por bases em dois e K+ em um experimento. Ocorreu redução dos teores de Cu, Fe e H + Al em dois experimentos e Zn em um ensaio. Segundo os resultados, a solarização promoveu alterações nas propriedades físicas, químicas e biológicas dos solos, melhorando a estrutura, liberando nutrientes e

The Big Bang of tissue growth: Apical cell constriction turns into tissue expansion.

Science.gov (United States)

Janody, Florence

2018-03-05

How tissue growth is regulated during development and cancer is a fundamental question in biology. In this issue, Tsoumpekos et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201705104) and Forest et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201705107) identify Big bang (Bbg) as an important growth regulator of the Drosophila melanogaster wing imaginal disc. © 2018 Janody.

ESDIS DOI System, Approach, and Future Direction

Science.gov (United States)

Wanchoo, L.; James, N.

2013-12-01

NASA's Earth Science Data and Information System (ESDIS) Project began investigating the use of Digital Object Identifiers (DOIs) in 2010 with the goal of assigning DOIs to various data products. These data products are archived and distributed by various Distributed Active Archive Centers (DAACs) located across the United States. Each data center has a unique approach and process for generating and archiving a variety of data products that are used for global change research. These varied approaches present a challenge for developing a DOI solution that fits all the possible variations. To address this challenge, ESDIS developed processes, guidelines, and several models for creating and assigning DOIs. Initially the system was started as a prototype approach and now it is fully operational. In February 2012, ESDIS joined the California Digital Library (CDL) EZID for registering the EOSDIS-related DOIs. ESDIS's DOI operational process allows for reserving DOIs while data providers are finalizing the DOIs and its associated elements. This flexibility allows data providers to embed and test the DOI in the data product metadata before formally registering with EZID. Data providers can change any DOI metadata, including the DOI name as long as it has not been registered or reserved by another data provider. ESDIS assures the uniqueness of the DOI names before it is registered. Currently, ESDIS has 146 data product DOIs registered with EZID and data providers have reserved an additional 93 DOIs with ESDIS. A semi-automated approach is being developed for processing and validating the DOI information provided by the data providers and will cover all the steps from the collection to the registration of DOIs. ESDIS's DOI concept utilizes a few mandatory metadata elements that effectively identify the data products and the source of availability. Of these elements, the Uniform Resource Locator (URL) attribute has the very important function of identifying the landing page

Control biológico de ácaros Tetranychidae

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Acosta Gómez Alfredo

1992-12-01

Full Text Available En este articulo, se presenta información publicada e inédita y, también, se realiza una revisión bibliográfica exhaustiva de los enemigos naturales de T. cinnabarinus y T. urticae, tanto a nivel mundial, como a nivel nacional, con el propósito de despertar el interés e informar sobre las bondades del control
biológico de los ácaros Tetranychidae y, en los casos donde es posible, se proporciona alguna información correspondiente a su efectividad. Posteriormente, se plantea una discusión resumida y se sugieren algunas propuestas de comportamiento estratégico o de utilidad potencial que podrían ser adoptadas por los profesionales comprometidos o
responsables de los cultivos de flores para promover
la ampliación del uso de enemigos naturales de los ácaros y utilizar, entre otros, métodos o estrategias biológicas, culturales o flsicas, que ayuden a disminuir la frecuencia del uso de agroquímicos y, así, conservar un ambiente menos contaminado y menos perjudicial para la humanidad del futuro.

Nutrient recycling of sorghum straw and soil biological attributes in Eastern Amazon Reciclagem de nutrientes da palhada de sorgo e atributos biológicos do solo na Amazônia Oriental

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Patrícia Ribeiro Maia

2012-10-01

Full Text Available The microbial biomass and activity are biological indicators sensitive to environmental changes caused by agricultural use and can provide important information for the planning of adequate land use. The objective of this research was to evaluate the nutrient recycling, persistence, and biological attributes of sorghum straw in Oxisol as a function of soil management systems. The experiment was carried out at the Federal Rural University of Amazonia in randomized block design with 3 x 2 factorial and four replicates. Three sorghum hybrids and two soil management systems were the factors used to assess straw decomposition. In order to evaluate the biological attributes, a 2 x 2 factorial experiment with four replicates was carried out using two soil management systems and two sampling dates. Total organic carbon (TOC, carbon in the soil microbial biomass (C-SMB, C-SMB/TOC ratio, basal respiration and metabolic quotient (qCO2 were investigated. The Qualimax hybrid presented the highest C/N ratio (55 and longer straw persistence in soil after 120 days of management (35%. The highest TOC, C-SMB, C-SMB/TOC ratio, and basal respiration and the smallest qCO2 were observed during the rainy season and in the no-till system.A atividade e biomassa microbiana são indicadores biológicos sensíveis a alterações ambientais decorrentes do uso agrícola, podendo fornecer informações importantes para o uso adequado do solo. Objetivou-se, com este trabalho, avaliar a ciclagem de nutrientes, atributos biológicos e a persistência da palhada de sorgo em um Latossolo Amarelo distrófico, em função de sistemas de manejo do solo. O experimento foi realizado na Universidade Federal Rural da Amazônia, em um delineamento em blocos casualizados, com fatorial 3 x 2 e quatro repetições. Os fatores foram: três híbridos de sorgo e dois sistemas de manejo do solo, para avaliar a decomposição da palhada. Para avaliar os atributos biológicos, um experimento com

Hipótesis de progresión del conocimiento biológico y del conocimiento didáctico del contenido biológico. Parte I: referentes teóricos

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Édgar Orlay Valbuena Ussa

2012-04-01

Full Text Available Este artículo, constituye el primero de una serie de dos, consistentes en el abordaje de dos constituyentes fundamentales del conocimiento profesional del profesor de Biología. Primero se presenta la perspectiva del autor sobre el conocimiento profesional del profesor de Biología, y el conocimiento didáctico del contenido biológico (CDCB; luego, a partir de la revisión de antecedentes y de referentes teóricos, se propone una hipótesis de progresión tanto para el conocimiento biológico (estructuras sintáctica y sustantiva como para el CDCB. Para el caso del primer conocimiento, la hipótesis plantea dos extremos: la perspectiva fisicalista y la visión estructural-sistémica; en cuanto al CDCB, la hipótesis plantea dos polos: el reduccionismo biológico y la perspectiva integradora-transformadora. Posteriormente, en el segundo artículo se presentarán los resultados de investigación, a partir del análisis de datos de estudios obtenidos con futuros profesores de Biología.

First measurement of target and double spin asymmetries for polarized e- polarized p --> e p pi0 in the nucleon resonance region above the Delta(1232)

Energy Technology Data Exchange (ETDEWEB)

Biselli, Angela; Burkert, Volker; Amaryan, Moscov; Amaryan, Moskov; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Baltzell, Nathan; Battaglieri, Marco; Bedlinskiy, Ivan; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Blaszczyk, Lukasz; Bookwalter, Craig; Boyarinov, Sergey; Bosted, Peter; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Bultmann, S.; Bueltmann, Stephen; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crede, Volker; Dale, Daniel; Dashyan, Natalya; De Masi, Rita; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Deur, Alexandre; Dhamija, Seema; Dickson, Richard; Djalali, Chaden; Dodge, Gail; Doughty, David; Dugger, Michael; Dzyubak, Oleksandr; Egiyan, Hovanes; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feuerbach, Robert; Fersch, Robert; Forest, Tony; Fradi, Ahmed; Garcon, Michel; Gavalian, Gagik; Gevorgyan, Nerses; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gohn, Wesley; Gothe, Ralf; Graham, Lewis; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Hassall, Neil; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Keller, Dustin; Kellie, James; Khandaker, Mahbubul; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Kossov, Mikhail; Krahn, Zebulun; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Mirazita, Marco; Mokeev, Viktor; Moreno, Brahim; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Nasseripour, Rakhsha; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kil; Park, Seungkyung; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pogorelko, Oleg; Pozdnyakov, Sergey; Price, John; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Saini, Mukesh; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schott, Diane; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Sober, Daniel; Sokhan, Daria; Stavinskiy, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Watts, Daniel; Weinstein, Lawrence; Weygand, Dennis; Williams, M.; Wolin, Elliott; Wood, Michael; Yegneswaran, Amrit; Yurov, Mikhail; Zana, Lorenzo; Zhang, Jixie; Zhao, Bo; Zhao, Zhiwen

2008-10-01

DOI: http://dx.doi.org/10.1103/PhysRevC.78.045204
The exclusive channel polarized proton(polarized e,e prime p)pi0 was studied in the first and second nucleon resonance regions in the Q2 range from 0.187 to 0.770 GeV2 at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). Longitudinal target and beam-target asymmetries were extracted over a large range of center-of-mass angles of the pi0 and compared to the unitary isobar model MAID, the dynamic model by Sato and Lee, and the dynamic model DMT. A strong sensitivity to individual models was observed, in particular for the target asymmetry and in the higher invariant mass region. This data set, once included in the global fits of the above models, is expected to place strong constraints on the electrocoupling amplitudes A_{1/2} and S_{1/2} for the Roper resonance N(1400)P11, and the N(1535)S11 and N(1520)D13 states.

Association of Polar Early Career Scientists Promotes Professional Skills

Science.gov (United States)

Pope, Allen; Fugmann, Gerlis; Kruse, Frigga

2014-06-01

As a partner organization of AGU, the Association of Polar Early Career Scientists (APECS; http://www.apecs.is) fully supports the views expressed in Wendy Gordon's Forum article "Developing Scientists' `Soft' Skills" (Eos, 95(6), 55, doi:10.1002/2014EO060003). Her recognition that beyond research skills, people skills and professional training are crucial to the success of any early-career scientist is encouraging.

Accidentes biológicos en estudiantes de medicina de una universidad peruana: prevalencia, mecanismos y factores de riesgo

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Elizabeth Inga

2010-03-01

Full Text Available Introducción: Una de las más serias amenazas que enfrentan los estudiantes de medicina durante su práctica clínica es la posibilidad de exposición a accidentes biológicos, debido en la mayoría de los casos a la inexperiencia y el escaso desarrollo de las habilidades manuales. Objetivos: Establecer la frecuencia, mecanismos, circunstancias y factores de riesgo de los accidentes biológicos ocurridos entre estudiantes de medicina. Diseño: Estudio descriptivo observacional de corte transversal. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Participantes: Estudiantes de medicina. Metodología: Se aplicó una encuesta estructurada anónima, voluntaria y autoadministrada. Principales medidas de resultados: Accidentes biológicos. Resultados: En total fueron 307 entrevistados. La prevalencia de accidentes biológicos en la población estudiada fue de 51,5% (158/307. La media de accidentes biológicos en el último año fue de 1,06. El 91,1% de los estudiantes del último año presentó al menos un accidente biológico, versus 11,9% en los estudiantes del primer año. Los estudiantes del último año informaron con más frecuencia accidentes de riesgo alto para transmisión de infecciones, siendo 47,6% por pinchazo con objeto punzocortante, y 80,6% tuvo exposición a sangre; los accidentes de riesgo alto son mucho más frecuentes en quirófanos y sala de partos (51,9%. Conclusiones: La prevalencia de accidentes biológicos fue 51,5%, siendo el pinchazo la forma más frecuente. Es necesario desarrollar estrategias que permitan velar por la bioseguridad de los estudiantes de medicina.

Polarization-Independent Electrically Tunable Holographic Polymer Dispersed Liquid Crystals Grating Doped with Chiral Molecules

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Hui LI

2017-08-01

Full Text Available This study proposes a holographic grating made of polymer dispersed liquid crystal (PDLC, with a small amount of chiral molecules doped into PDLC material. The major advantage of this grating is that it is independent of light polarization. This characteristic was verified by applying the interference beam intensity of a He-Cd laser at 150 mW/cm2, with an incidence angle between the two interference beams of 24°, for an irradiation curing duration of 120 s. The observed periodic structure of the grating is consistent with the theoretical value. As chiral molecules are doped, nematic-LC experiences a phase-change in the grating. However, the electro-optical features are only slightly affected. This proposed grating has greatly potential in 3D imaging because of its polarization-independent feature.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.16312

Medición de Activos Biológicos en Marcos Conceptuales Comparados

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Beatriz Brozzú

2008-12-01

Full Text Available En este ensayo, no solamente pretendemos seguir probando que las NCP FAPCE (Argentina son la consecuencia de un criterio absolutamente normativista y por lo tanto restrictivo y limitado, mientras que las NIIF y las FASB se fundamentan en un paradigma basado en la “utilidad para el decisor”, o sea en las necesidades del usuario de la información. Lo que también concluiremos es que esta esencial diferencia es la causa por la cual el amplio criterio aplicado por la NIIF 41 –Activos biológicos– y la armoniosa coherencia con su Marco Conceptual, le permiten al Sistema de Información Contable lograr su principal objetivo, cual es mostrar “valor real” para todos los Activos. Por el contrario, y para que las NCP FACPCE argentinas puedan ser realmente un sistema de información útil, y en el caso especifico de la RT22 FAPCE –Activos biológicos–, ésta debe apartarse de su Marco conceptual para poder valuar los Activos Biológicos destinados a ser utilizados en el proceso productivo a un valor corriente (considerado razonablemente representativo de su valor real puesto que de respetar el Marco Conceptual debería valuarlos a valor histórico.

Atividade biológica de Davilla kunthii A. St. –Hil. (Dilleniaceae

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L.S.N. NASCIMENTO

2016-03-01

Full Text Available RESUMO Davilla kunthii A. St. –Hil. (Dilleniaceae tem ampla distribuição vegetal. Sua família agrega uma quantidade significativa de novas substâncias, bem como importantes atividades biológicas. O uso mais comum é na medicina alternativa para combater algumas doenças, mas estudos comprovam diferentes atividades biológicas de interesse farmacológico. A literatura sobre a bioatividade de D. kunthii é incipiente. Por esta razão, os objetivos deste trabalho se concentraram em verificar os efeitos biológicos do extrato das folhas de D. kunthii, através de bioensaios frente a microrganismos patógenos Escherichia coli, Salmonella tiphymurium (bactérias gram-negativa, Staphylococcus aureus e Streptococcus sanguinis (bactérias gram-positiva, ao fungo tipo levedura Candida albicans e aos fungos filamentosos Aspergillus flavus e Fusarium proliferatum. A pesquisa verificou ainda a atividade redutora da enzima de acetilcolinesterase, e, também, foi observada a atividade antioxidante via DPPH (2,2-difenil-1-picril-hidrazila e de toxicidade frente ao microcrustáceo A. salina. Os resultados apontaram significativas atividades antioxidante, antimicrobiano, atingindo até 90% de inibição sobre a levedura C. albicans em todas as concentrações.

Endocardite em prótese biológica por candida parapsilosis

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Luiz Carlos Severo

1987-02-01

Full Text Available Relata-se um caso de endocardite causada pela Candida parapsilosis numa prótese valvular biológica em posição mitral. Revisa-se brevemente a literatura brasileira sobre o assunto.

Guerra biológica, bioterrorismo e saúde pública

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Luiz Jacintho da Silva

Full Text Available O uso de agentes biológicos como arma não é novidade para a humanidade. Durante séculos, até a atualidade, a guerra biológica tem sido objeto de muita pesquisa e especulação, mas de pouca ação. O medo de efeitos contrários e dúvidas sobre sua eficiência como armas devem ter limitado seu uso. Recentemente, se verificou uma nova forma de terrorismo, empregando agentes infecciosos, devagar e sem muito alarde, até as ocorrências recentes com o Bacillus anthracis nos Estados Unidos. A varíola é possivelmente o mais devastador desses agentes. Menos de 25 anos passados desde sua erradicação, a saúde pública tem que lidar com a possibilidade de sua re-introdução. O cenário da re-introdução da varíola no Brasil é discutido.

Guerra biológica, bioterrorismo e saúde pública

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Silva Luiz Jacintho da

2001-01-01

Full Text Available O uso de agentes biológicos como arma não é novidade para a humanidade. Durante séculos, até a atualidade, a guerra biológica tem sido objeto de muita pesquisa e especulação, mas de pouca ação. O medo de efeitos contrários e dúvidas sobre sua eficiência como armas devem ter limitado seu uso. Recentemente, se verificou uma nova forma de terrorismo, empregando agentes infecciosos, devagar e sem muito alarde, até as ocorrências recentes com o Bacillus anthracis nos Estados Unidos. A varíola é possivelmente o mais devastador desses agentes. Menos de 25 anos passados desde sua erradicação, a saúde pública tem que lidar com a possibilidade de sua re-introdução. O cenário da re-introdução da varíola no Brasil é discutido.

Guerra biológica, bioterrorismo e saúde pública

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Luiz Jacintho da Silva

2001-12-01

Full Text Available O uso de agentes biológicos como arma não é novidade para a humanidade. Durante séculos, até a atualidade, a guerra biológica tem sido objeto de muita pesquisa e especulação, mas de pouca ação. O medo de efeitos contrários e dúvidas sobre sua eficiência como armas devem ter limitado seu uso. Recentemente, se verificou uma nova forma de terrorismo, empregando agentes infecciosos, devagar e sem muito alarde, até as ocorrências recentes com o Bacillus anthracis nos Estados Unidos. A varíola é possivelmente o mais devastador desses agentes. Menos de 25 anos passados desde sua erradicação, a saúde pública tem que lidar com a possibilidade de sua re-introdução. O cenário da re-introdução da varíola no Brasil é discutido.

Un Nobel para el tiempo biológico

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Diego Golombek

2018-01-01

Full Text Available El premio Nobel en Fisiología o Medicina de 2017 fue otorgado a tres investigadores norteamericanos pioneros en el descubrimiento del mecanismo de los ritmos circadianos. Ya era hora… y es una excelente excusa para destacar la importancia de la Cronobiología – la ciencia que estudia los ritmos y relojes biológicos - tanto en la vida cotidiana en general como en las ciencias médicas en particular.

História dos tratamentos biológicos Biologicals treatments's history

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Sérgio Paulo Rigonatti

2004-01-01

Full Text Available Contexto: Trata-se de uma discussão de como surgiram os tratamentos biológicos no decorrer da história da psiquiatria.Context: It's about a discussion on how begun the biological treatment throughout Psychiatry History.

Manejo biológico de nematodos fitoparásitos con hongos y bacterias

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Ricardo Piedra Naranjo

2013-05-01

Full Text Available La agricultura actual demanda la reducción de plaguicidas químicos y la introducción de sistemas sostenibles con el uso de agentes de manejo biológico.  La alternativa de usar hongos y bacterias para el manejo de nematodos fitoparásitos puede ser una opción biológica muy importante de actualidad. El manejo biológico de nematodos fitoparásitos es posible si se logra fomentar e investigar la utilización de hongos y bacterias que pueden estar en el suelo o, de lo contrario, reproducirse en laboratorios para uso comercial. En revisión de literatura se encontró varios organismos (hongos y bacterias que pueden ser utilizados por agricultores, y en algunos casos, ya están siendo aplicados. Entre los organismos encontrados, tenemos las bacterias Pasteuria penetrans, Pseudomonas (Burlkoldelia cepacia tipo Wisconsin.  Algunos hongos como: Verticillium chlamydosporium. Arthtrobotrys y Monacrosporium, Catenaria spp, Drechmeria coniospora, Pleurotus ostreatus, Pleurotus spp. Fusarium solani, Cylindrocarpon cylindroides y Paecilomyces lilacinus, Verticillium lecanii, Arthrobotrys conoides, A. musiformis, A.  robusta, Monoacrosporium ellipsosporum, Dactylaria thaumasia, Cylindrocarpon sp., Trichoderma harzianum, Dactylella brochophaga, Arthrobotrys oligospora y Arthrobotrys botryospora y Myrothecium verrucaria. Con este tipo de información, planteada desde el punto de vista en investigaciones agropecuarias, se podría tener posibilidades de utilizar nematicidas biológicos en el manejo de nematodos fitoparásitos, desarrollando un manejo integrado de plagas, donde se tendría la posibilidad de no usar de nematicidas químicos en un futuro, o por lo menos reducir sustancialmente su uso en nuestra agricultura y así mejorar la relación con el medio ambiente y el ser humano.

Griesinger e as bases da "Primeira psiquiatria biológica"

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Mário Eduardo Costa Pereira

2007-12-01

Full Text Available Wilhelm Griesinger foi um personagem central na história da psiquiatria alemã. Considerado por muitos como um dos "pais da psiquiatria biológica", sua obra, na verdade, é extremamente complexa, apoiando-se em uma sofisticada teoria do eu e das desestruturação dos processos mentais na psicopatologia.

Informatividade dos lucros contábeis e divulgação dos ativos biológicos: evidências brasileiras

OpenAIRE

Holanda, Allan Pinheiro

2013-01-01

A pesquisa tem o objetivo de investigar a influência exercida pela divulgação dos ativos biológicos na informatividade dos lucros contábeis nas firmas brasileiras listadas na BM&FBovespa, considerando-se o período de 2010 a 2011. Para a investigação da informatividade dos ativos biológicos foi utilizada a adaptação dos modelos propostos por Easton e Harris (1991) e Francis e Schipper (1999). Os ativos biológicos, por sua vez, foram mensurados de duas maneiras, pela simples existência da c...

El progreso biológico

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Barahona, Ana

1997-12-01

Full Text Available Not available.La idea de progreso en Biología está ligada al concepto de scala naturae o la gran cadena del ser que se puede trazar hasta Aristóteles. Esta noción de que los organismos vivientes pueden clasificarse en una jerarquía de inferior a superior tomó formas nuevas en los siglos XVII y XVIII. En el siglo XVIII, naturalistas como Buffon, Bonnet y Robinet se habían preguntado si podíamos hablar de un patrón definido de desarrollo. En el siglo XIX, Lamarck postula la idea de que existe una progresión de los organismos menos avanzados a los organismos más avanzados. Posteriormente, la teoría de la evolución añade la dimensión temporal y de continuidad genética o histórica a la clasificación jerárquica de los seres vivos. Darwin pensaba que la selección natural traía como resultado el perfeccionamiento y que éste inevitablemente conduciría al progreso gradual de la organización. Herbert Spencer se convirtió en uno de los darwinistas más radicales del siglo XIX y principios del XX. Para Spencer la idea de progreso se aplicaba no solo al mundo biológico sino que era parte de una ley general, que dirigía lo simple hacia lo complejo, lo homogéneo a lo heterogéneo. Posteriormente, Julian Huxley, Theodosius Dobzhansky, Ernst Mayr, George Gaylord Simpson y Ledyard Stebbins —conocidos como los arquitectos de la Sintesis Moderna— comparten una visión progresionista de la evolución biológica. La noción de progreso evolutivo, en la actualidad, es sumamente controvertida, y se pueden distinguir básicamente tres diferentes perspectivas. La primera, defendida por Michael Ruse y David Hull entre otros, sostiene que no existe evidencia científica que nos lleve a aceptar cierta «direccionalidad» en la evolución biológica. Una segunda visión, defendida por Stephen J. Gould, sostiene que, en la medida en que reemplacemos el término de progreso (ya que éste es antropocéntrico por el de «noción operacional de

Summer abundance and activities of bacteria in the freshwater lakes of Schirmacher Oasis, Antarctica

Digital Repository Service at National Institute of Oceanography (India)

Ramaiah, N.

stream_size 7 stream_content_type text/plain stream_name Polar_Biol_15_547.pdf.txt stream_source_info Polar_Biol_15_547.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

Trombose de prótese biológica mitral: importância do ecocardiograma transesofágico no diagnóstico e acompanhamento pós-tratamento Bioprosthetic mitral valve thrombosis: importance of transesophageal echocardiography in the diagnosis and follow-up after treatment

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Adelino Parro Jr

2004-04-01

Full Text Available OBJETIVO: Descrever os achados clínicos e ecocardiográficos de trombose em prótese biológica mitral e o valor do ecocardiograma transesofágico (ETE no diagnóstico e monitoração da lise do trombo. MÉTODOS: Foram estudados ao ETE 111 pacientes com prótese biológica mitral, e incluídos 4 de 7 com suspeita de trombo nestas próteses (idade média = 60,2±10,2 anos; 2 homens. O diagnóstico pôde ser confirmado pela realização seriada do ETE e pela evolução clínica. Investigaram-se os aspectos morfológicos dos folhetos da prótese, e presença e característica das massas ecogênicas anexas. Foram obtidos o gradiente médio pela prótese e a área valvar. RESULTADOS: O diagnóstico de trombo em prótese biológica mitral foi realizado 48,7±55,2 meses após a cirurgia. Dois pacientes apresentaram acidente vascular encefálico isquêmico no pós-operatório imediato. O gradiente médio global estava elevado (11,4±3 mmHg e a área valvar reduzida (1,24±0,3cm². Ao ETE, em todos foram evidenciadas massas ecogênicas em face ventricular esquerda da prótese biológica mitral, sugestivas de trombo. No ETE seriado (136±233 dias, houve desaparecimento do trombo em dois casos e redução do trombo nos outros dois, após tratamento. O gradiente médio reduziu para 6,2±3 mmHg (p=0,004; IC 95%, e a área valvar aumentou para 2,07±0,4 (p=ns. CONCLUSÃO: O ETE mostrou-se útil na detecção de trombo em prótese biológica mitral e eficaz na monitoração do tratamento, em todos casos.OBJECTIVE: To report the clinical and echocardiographic findings of bioprosthetic mitral valve thrombosis and the value of transesophageal echocardiography (TEE in its diagnosis and monitoring of thrombolysis. METHODS: One hundred and eleven patients with mitral bioprostheses underwent TEE, and 4 out of 7 suspected of having a thrombus on these prostheses were included in the study (mean age = 60.2±10.2 years; 2 men. The diagnosis was confirmed with serial

Riesgo biológico y prácticas de bioseguridad en docencia

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Alejandra M. Diaz-Tamayo

2016-02-01

Full Text Available Resumen Los riesgos ocupacionales a los cuales están expuestos los docentes del área de salud, aumentan con el desempeño de sus actividades asistenciales y prácticas formativas con estudiantes, por esto durante su formación profesional se exigen conocimientos, juicio crítico, desarrollo de habilidades y destrezas en el cumplimiento de sus funciones. Objetivo: evaluar el conocimiento en riesgo biológico y el cumplimiento de las prácticas de bioseguridad en el personal docente, responsable de la formación clínica de los estudiantes de los programas académicos de la Facultad de Salud de una Institución de Educación Superior. Metodología: estudio descriptivo, de corte transversal, con una muestra de 78 docentes, entrevistados personalmente y en sus áreas de trabajo. Se evaluaron variables de conocimiento respecto al concepto que tienen los docentes sobre riesgo biológico y bioseguridad y la variable de prácticas respecto al cumplimiento de normas de bioseguridad. Resultados: la tercera parte de los docentes evaluados conocen sobre riesgo biológico y bioseguridad y en un porcentaje menor se evidenció la aplicación de prácticas de bioseguridad. No se observaron relaciones estadísticamente significativas entre conocimiento en riesgo biológico y bioseguridad y tipo de vinculación y antigüedad docente. Discusión: los docentes reconocen la exposición al riesgo biológico, pero preocupa la baja utilización de medidas de bioseguridad y de procedimientos recomendados para prevenir accidentes. Conclusiones: se espera que los docentes del área de la salud tengan un alto conocimiento sobre riesgo biológico y aplicación de normas de bioseguridad, pero esta investigación demostró las deficiencias en este tema por la población estudiada. Abstract Professors working in the field of health are exposed to occupational risks that increase as they perform their care and teaching activities with students. Thus their professional

Control biológico de moscas blancas en cultivo de tomate: interacciones entre sus enemigos naturales

OpenAIRE

Moreno Ripoll, Rafael

2011-01-01

[spa] Para obtener un control biológico adecuado de las plagas presentes en un cultivo es importante determinar las relaciones tróficas que existen entre los enemigos naturales y su efecto sobre el control de estas plagas. Dos de estas interacciones, la depredación intragremial y el canibalismo, pueden condicionar el éxito de los programas de control biológico produciendo efectos aditivos o negativos sobre las poblaciones de la plaga. Para determinar la ingesta de todos los estados de desarro...

Percepción del riesgo biológico en dos entidades de ciencia del sector salud en Holguín: cuba

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Dailín Cobos Valdes

Full Text Available Introducción: La temática sobre la percepción de riesgos resulta de gran actualidad e importancia porque su interpretación conduce al enfrentamiento de comportamientos humanos diversos. La misma puede ser aplicada a problemas de mayor especialización como el riesgo tecnológico o biológico. Las entidades con riesgo biológico deben conocer la percepción de sus trabajadores para poder organizar la Seguridad Biológica y proteger al trabajador ocupacionalmente expuesto. Las dos entidades de ciencia con riesgo biológico del sector salud en Holguín no presentan esta determinación. Objetivo: Determinar la percepción de riesgo biológico en estas entidades. Materiales y Métodos: Para determinar la percepción del riesgo biológico, se empleó el programa RISKPERCEP, se utilizó también el método Delphi para validar la encuesta elaborada ajustada al grupo de estudio. Resultados: La percepción del riesgo en las dos entidades fue baja. Este resultado tiene notables implicaciones en la Bioseguridad, ya que al no valorar el riesgo al que están expuestos, los trabajadores, se familiarizan con las actividades con riesgo biológico que ejecutan diariamente y son proclives a cometer fallas. En sentido general, en las dos entidades, las variables a nivel de individuos y de la naturaleza del riesgo se encuentran subestimadas y las de gestión se encuentran sobrestimadas. Conclusiones: Los estudios realizados permiten determinar sobre qué aspectos debe incidirse para regular la sobrestimación o subestimación del riesgo, los que son esenciales en el diseño de políticas adecuadas de capacitación y en la preparación de mensajes de prevención en el ámbito laboral.

DOI in scientific journals of SciELO portal

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Sandra Gisela Martín

2013-10-01

Full Text Available The research provides a description of the SciELO journals portal and the DOI identifier through its range, year of creation, history, management, policy, structure, ISBN-A and reference sources. It provides information on the implementation of the DOI in citations styles APA and Vancouver, and standards ISO 690-2010 and ABNT6023-2002. The work aimed to explore the degree of implementation of the DOI in scientific journals in SciELO, identify where DOI display, knowing the amount of publishers as DOI prefix, determine the number of journals titles including the ISSN suffix code and identify the degree of implementation of the DOI in the styles and standards of citations available in SciELO. Descriptive methodology was applied where data were collected through direct observation of the websites of the 898 current journals available between the months of December 2012 and January 2013 in SciELO portal. It concludes that less than 50% of the countries in SciELO are currently using the DOI in its publications, primarily displayed code in HTML files, only 30 of the 929 publishers implemented it and most include the ISSN identifier within the suffix. While using the DOI in all citations of the articles, not does so strict as the provisions of the rules and styles.

Caracterização morfológica, perfil químico, atividade biológica e conservação in situ do gênero Lychnophora Mart. (Asteraceae: Vernonieae: Lychnophorinae, Brasil

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Paulo Sérgio Siberti da Silva

2013-02-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n2p9   Muitas pessoas que habitam as regiões do cerrado utilizam espécies vegetais para fins terapêuticos. No entanto, devido ao intenso extrativismo de algumas espécies, populações botânicas nativas correm o risco de desaparecer ou sofrer drástica redução, como exemplo, indivíduos do gênero Lychnophora. Este contém 24 espécies distribuídas nas categorias vulnerável, em perigo, criticamente em perigo e provavelmente extintas. Esses indivíduos são conhecidos na medicina popular como “arnica” e suas folhas e flores são utilizadas, comumente, como anti-inflamatórios, analgésicos e cicatrizantes. O perfil químico do gênero é caracterizado pela presença de lactonas sesquiterpênicas, sesquiterpenos, diterpenos, triterpenos, flavonoides, esteroides, poliacetilenos e derivados de cariofileno, contendo, também, lignanas com atividade analgésica. Estudos com espécies de Lychnophora mostraram resultados significativos quanto às suas atividades biológicas contra Leishmania amazonensis, Staphylococcus aureus e Tripanosoma cruzi. Dessa forma, o objetivo deste trabalho foi realizar um levantamento da morfologia, composição química e atividade biológica, bem como o uso e estado atual de conservação do gênero Lychnophora no Brasil.

The Influence of biol in the crop yield of Lactuca sativa L. variety Iceberg

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Pomboza-Tamaquiza Pablo

2016-11-01

Full Text Available The objective of the research was to assess the influence of biol enriched with efficient micro-organisms, in the ecological cultivation of Lactuca sativa L (lettuce variety "Iceberg". The field test was carried out on the farm of Querochaca, Faculty of Sciences Agriculture, of the Technical University of Ambato. The studied factors were doses of biol (2%, 4% and 6% and frequencies of application (8 and 15 days, I know used the experimental design of complete blocks at random, with factorial arrangement of 3x2 1 with three repetitions. We evaluated: plant height, diameter of the main stem, days to harvest, weight and diameter of the bud commercial, performance in kg/plot neta and performance in kg/experimental unit, conducted the significance test of Duncan to 5%. The results showed that the dose of 6 per cent applied every 15 days treatment D3F2, contributed to the larger diameter of the bud commercial (25.9 cm; the greater weight of cogollo commercial (1.14 kg and the higher performance (549 kg/experimental unit. This suggests that the implementation of biol can be an important ecological alternative to fertilize organic farming as the lettuce by reducing the use of fertilizers in chemical synthesis and production costs.

Electrodo biológico con la enzima hidrogenasa, procedimiento de obtención y sus aplicaciones

OpenAIRE

Fernández López, Víctor Manuel; López de Lacey, Antonio; Rüdiger Ortiz, Olaf

2005-01-01

Electrodo biológico con la enzima hidrogenasa, procedimiento de obtención y sus aplicaciones. En la presente invención se protegen electrodos biológicos modificados con enzimas hidrogenasas (ánodos) mediante los cuales es posible obtener energía eléctrica del hidrógeno en una configuración típica de pilas de combustible; asimismo, con estos electrodos modificados con hidrogenasa (cátodos) es posible producir hidrógeno a partir de agua en una configuración típica de cél...

Contribuições a estudos biológicos com o uso de modelos biofísicos

OpenAIRE

de Cássia Moura do Nascimento, Rita

2004-01-01

Um modelo biofísico é uma representação simplificada e/ou abstrata de processos ou sistemas biológicos. Objetivando ampliar o conhecimento sobre a modelagem biofísica, esta Tese enfoca prioritariamente os modelos que desenvolvemos, visando contribuir com os estudos biológicos. Proteínas transportadoras do tipo canal iônico encontram-se presentes na membrana plasmática de todos os seres vivos e o primeiro modelo biofísico é uma membrana plasmática artificial, na qual há um co...

Biolingüística y capacidad humana Biolinguistics and Human Capacity

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Chomsky Noam Abraham

2006-06-01

Full Text Available Este artículo presenta de manera sucinta el enfoque llamado 'biolingüístico' que empezó a desarrollarse en los primeros años de la posguerra, teniendo en cuenta los avances de la biología y las matemáticas. Se pasa revista a algunos postulados de la neurociencia (i.e. ciencia cognitiva en lo concerniente a la 'facultad del lenguaje', así como a los dos últimos modelos de la GG: el modelo de 'Principios y Parámetros' (P&P y el modelo 'Minimalista'. Estos últimos buscan responder las cuestiones fundamentales de la biología del lenguaje, su naturaleza, uso y evolución. Desde este punto de vista, se trata de caracterizar el equipamiento biológico gracias al cual los seres humanos adquieren una gramática. Así las cosas, se considera el equipamiento biológico como una función que asocia experiencia y gramática.This paper depicts a brief account of the so-called ´biolinguistic´ approach which dates back to the first postwar years, by taking into account progress in biology and mathematics. Some postulates of neuroscience (i.e. cognitive science regarding the ´faculty of language´ as well as the last two models of GG: the ´Principles and Parameters´ (P&P and the ´Minimalist´ models are reviewed. The latter aim to provide answers to key questions on the biology of language, its nature, its use, and its evolution. From this standpoint it has been attempted to characterize the biological endowment which allows human beings to acquire a grammar. Thus the biological endowment is seen as a function relating experience to grammar.

Polarized emission from CsPbX3 perovskite quantum dots

Science.gov (United States)

Wang, Dan; Wu, Dan; Dong, Di; Chen, Wei; Hao, Junjie; Qin, Jing; Xu, Bing; Wang, Kai; Sun, Xiaowei

2016-06-01

Compared to organic/inorganic hybrid perovskites, full inorganic perovskite quantum dots (QDs) exhibit higher stability. In this study, full inorganic CsPbX3 (X = Br, I and mixed halide systems Br/I) perovskite QDs have been synthesized and interestingly, these QDs showed highly polarized photoluminescence which is systematically studied for the first time. Furthermore, the polarization of CsPbI3 was as high as 0.36 in hexane and 0.40 as a film. The CsPbX3 perovskite QDs with high polarization properties indicate that they possess great potential for application in new generation displays with wide colour gamut and low power consumption.Compared to organic/inorganic hybrid perovskites, full inorganic perovskite quantum dots (QDs) exhibit higher stability. In this study, full inorganic CsPbX3 (X = Br, I and mixed halide systems Br/I) perovskite QDs have been synthesized and interestingly, these QDs showed highly polarized photoluminescence which is systematically studied for the first time. Furthermore, the polarization of CsPbI3 was as high as 0.36 in hexane and 0.40 as a film. The CsPbX3 perovskite QDs with high polarization properties indicate that they possess great potential for application in new generation displays with wide colour gamut and low power consumption. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01915c

Medidas de bioseguridad adoptadas en el manejo con materiales biológicos en Laboratorios Liorad

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Nancy Burguet Lago

2013-03-01

Full Text Available Introducción: el trabajo con microorganismos puede conllevar a riesgos tanto para el personal que trabaja con los mismos como para el medio ambiente. La existencia de laboratorios de seguridad biológica y la implementación de medidas en la manipulación de los agentes biológicos minimizan el riesgo. Objetivo: evaluar las medidas de bioseguridad adoptadas en el manejo con materiales biológicos en Laboratorios Liorad. Métodos: empleo de una lista de chequeo y análisis de los resultados a través de una Matriz DAFO para valorar si el diseño de la instalación cumple con la bioseguridad. Además establecer un sistema documental para la manipulación de microorganismos y la confección de un plan de capacitación para el personal que trabaja en el laboratorio de control microbiológico. Resultados: la lista de chequeo permitió identificar como principal debilidad el no disponer de un doble pasillo para el traslado del material limpio y sucio. Como fortalezas, cumplir con las prácticas y procesamientos adecuados y el contar con equipos de seguridad biológica. El sistema documental incorporó a los procedimientos establecidos para la manipulación, un acápite referido a la «Peligrosidad y Medidas de Seguridad». El programa de capacitación desarrollado permitió proveer conocimientos específicos referidos a esta temática. Conclusión: las medidas adoptadas en el laboratorio permiten plantear que de manera general se cumplen los requisitos establecidos en materia de Bioseguridad para el trabajo con microorganismos.

Isolation of 2-deoxy-scyllo-inosose (DOI)-assimilating yeasts and cloning and characterization of the DOI reductase gene of Cryptococcus podzolicus ND1.

Science.gov (United States)

Ara, Satoshi; Yamazaki, Harutake; Takaku, Hiroaki

2018-04-01

2-Deoxy-scyllo-inosose (DOI) is the first intermediate in the 2-deoxystreptamine-containing aminoglycoside antibiotic biosynthesis pathway and has a six-membered carbocycle structure. DOI is a valuable material because it is easily converted to aromatic compounds and carbasugar derivatives. In this study, we isolated yeast strains capable of assimilating DOI as a carbon source. One of the strains, Cryptococcus podzolicus ND1, mainly converted DOI to scyllo-quercitol and (-)-vibo-quercitol, which is a valuable compound used as an antihypoglycemia agent and as a heat storage material. An NADH-dependent DOI reductase coding gene, DOIR, from C. podzolicus ND1 was cloned and successfully overexpressed in Escherichia coli. The purified protein catalyzed the irreversible reduction of DOI with NADH and converted DOI into (-)-vibo-quercitol. The enzyme had an optimal pH of 8.5 and optimal temperature of 35°C, respectively. The k cat of this enzyme was 9.98 s -1 , and the K m values for DOI and NADH were 4.38 and 0.24 mM, respectively. The enzyme showed a strong preference for NADH and showed no activity with NADPH. Multiple-alignment analysis of DOI reductase revealed that it belongs to the GFO_IDH_MocA protein family and is an inositol dehydrogenase homolog in other fungi, such as Cryptococcus gattii, and bacteria, such as Bacillus subtilis. This is the first identification of a DOI-assimilating yeast and a gene involved in DOI metabolism in fungi. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

The establishment of polarized membrane traffic in Xenopus laevis embryos.

Science.gov (United States)

Roberts, S J; Leaf, D S; Moore, H P; Gerhart, J C

1992-09-01

Delineation of apical and basolateral membrane domains is a critical step in the epithelialization of the outer layer of cells in the embryo. We have examined the initiation of polarized membrane traffic in Xenopus and show that membrane traffic is not polarized in oocytes but polarized membrane domains appear at first cleavage. The following proteins encoded by injected RNA transcripts were used as markers to monitor membrane traffic: (a) VSV G, a transmembrane glycoprotein preferentially inserted into the basolateral surface of polarized epithelial cells; (b) GThy-1, a fusion protein of VSV G and Thy-1 that is localized to the apical domains of polarized epithelial cells; and (c) prolactin, a peptide hormone that is not polarly secreted. In immature oocytes, there is no polarity in the expression of VSV G or GThy-1, as shown by the constitutive expression of both proteins at the surface in the animal and vegetal hemispheres. At meiotic maturation, membrane traffic to the surface is blocked; the plasma membrane no longer accepts the vesicles synthesized by the oocyte (Leaf, D. L., S. J. Roberts, J. C. Gerhart, and H.-P. Moore. 1990. Dev. Biol. 141:1-12). When RNA transcripts are injected after fertilization, VSV G is expressed only in the internal cleavage membranes (basolateral orientation) and is excluded from the outer surface (apical orientation, original oocyte membrane). In contrast, GThy-1 and prolactin, when expressed in embryos, are inserted or released at both the outer membrane derived from the oocyte and the inner cleavage membranes. Furthermore, not all of the cleavage membrane comes from an embryonic pool of vesicles--some of the cleavage membrane comes from vesicles synthesized during oogenesis. Using prolactin as a marker, we found that a subset of vesicles synthesized during oogenesis was only released after fertilization. However, while embryonic prolactin was secreted from both apical and basolateral surfaces, the secretion of oogenic prolactin

DOI resolution measurement and error analysis with LYSO and APDs

International Nuclear Information System (INIS)

Lee, Chae-hun; Cho, Gyuseong

2008-01-01

Spatial resolution degradation in PET occurs at the edge of Field Of View (FOV) due to parallax error. To improve spatial resolution at the edge of FOV, Depth-Of-Interaction (DOI) PET has been investigated and several methods for DOI positioning were proposed. In this paper, a DOI-PET detector module using two 8x4 array avalanche photodiodes (APDs) (Hamamatsu, S8550) and a 2 cm long LYSO scintillation crystal was proposed and its DOI characteristics were investigated experimentally. In order to measure DOI positions, signals from two APDs were compared. Energy resolution was obtained from the sum of two APDs' signals and DOI positioning error was calculated. Finally, an optimum DOI step size in a 2 cm long LYSO were suggested to help to design a DOI-PET

Investigador Invitado. Control Biológico en Agroecosistemas Mediante el Manejo de Insectos Entomófagos

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Nicholls Clara Inés

1998-06-01

Full Text Available La importancia que tienen los enemigos naturales de los organismos nocivos ha sido reconocida desde hace varias décadas. Desafortunadamente la implantación del control biológico no ha tenido la dimensión deseada. El empleo indiscriminado de productos biocidas ha alterado la biodiversidad de los agroecosistemas. Los parasitoides y predatores han sufrido los efectos nocivos de los plaguicidas. Los enemigos naturales de las plagas juegan un papel trascendental en la regulación las poblaciones de insectos nocivos. Los predatores de la clase insecta se registran en diversos órdenes y la abundancia de especies es impresionante. Pero el conocimiento que se tiene sobre su importancia aún es parcial. Pero el conocimiento que se tiene sobre su importancia aun es parcial. En muchos países no se ha precisado aun la bondad de estos organismos y se les protege. En el caso de los parasitoides ocurre algo similar. Se afirma que su diversidad biótica es incalculable, pero se explotan muy pocas especies. En estos dos grupos descansan los proyectos de Control Biológico clásico. Los éxitos en proyectos de control biológico se reconocen y se han expandido en varios países pero se requiere de un mayor impulso. Debido a las exigencias de una producción agrícola sostenible se debe de apoyar en Control Biológico de Plagas. En este documento se plantean aspectos generales sobre el tema.

PDS, DOIs, and the Literature

Science.gov (United States)

Raugh, Anne; Henneken, Edwin

The Planetary Data System (PDS) is actively involved in designing both metadata and interfaces to make the assignment of Digital Object Identifiers (DOIs) to archival data a part of the archiving process for all data creators. These DOIs will be registered through DataCite, a non-profit organization whose members are all deeply concerned with archival research data, provenance tracking through the literature, and proper acknowledgement of the various types of efforts that contribute to the creation of an archival reference data set. Making the collection of citation metadata and its ingestion into the DataCite DOI database easy - and easy to do correctly - is in the best interests of all stakeholders: the data creators; the curators; the indexing organizations like the Astrophysics Data System (ADS); and the data users. But in order to realize the promise of DOIs, there are three key issues to address: 1) How do we incorporate the metadata collection process simply and naturally into the PDS archive creation process; 2) How do we encourage journal editors to require references to previously published data with the same rigor with which they require references to previously published research and analysis; and finally, 3) How can we change the culture of academic and research employers to recognize that the effort required to prepare a PDS archival data set is a career achievement on par with contributing to a refereed article in the professional literature. Data archives and scholarly publications are the long-term return on investment that funding agencies and the science community expect in exchange for research spending. The traceability and reproducibility ensured by the integration of DOIs and their related metadata into indexing and search services is an essential part of providing and optimizing that return.

Tratamiento de aguas industriales mediante reactor biológico de membranas

OpenAIRE

Aznar Jiménez, Antonio

2008-01-01

El Laboratorio de Ingeniería para el Tratamiento de Aguas de la Universidad Carlos III de Madrid, de investigación y servicios en el tratamiento de aguas residuales, optimiza el diseño y puesta a punto de reactores biológicos de membranas (MBR), indicados para obtener agua depurada de alta calidad y/o aumentar la capacidad de tratamiento.

Heterocronía, generadora de cambios biológicos

OpenAIRE

Picasso, Mariana

2007-01-01

El reloj biológico se ha acelerado o retrasado reiteradas veces a lo largo de la historia de los seres vivos. De este modo, se han modificado tanto los tiempos del desarrollo general del cuerpo, como de una estructura en particular, e incluso el tiempo en el que se produce la maduración sexual del organismo. Estos cambios temporales se denominan eventos de heterocronía (del griego, heteros: distinto, chronos: tiempo) y son una piedra angular del proceso evolutivo. Las heterocronías son respon...

Maduración biológica y aptitudes cognitivas

OpenAIRE

Asensio Aguilera, Josep M.

1987-01-01

El avance experimentado por algunas disciplinas biológicas en los ultimos años ha permitido comprender mejor ciertas características de los procesos de desarrollo del cerebro que revelan un claro interés pedagógico. De los datos proporcionados por la Neurobiología y la Cronobiología se desprende la apreciable influencia que ejerce el ambiente en la composición y estructura del neocórtex, al igual que la existencia de un ritmo de desarrollo cerebral variable, segun los sujetos, dentro de las p...

DOI: https://dx.doi.org/10.4314/rj.v2i1.1A Dear Rwanda Journal ...

African Journals Online (AJOL)

Corporate Edition

DOI: https://dx.doi.org/10.4314/rj.v2i1.1A. EDITORIAL. Dear Rwanda Journal Series A readers,. On behalf of the editorial board, I am pleased to have this volume number 2 of Rwanda Journal of. Arts and Humanities out! With contributions from scholars and lecturers in the field of arts and humanities and philosophy, this ...

Fatores associados à exposição ocupacional com material biológico entre profissionais de enfermagem

Directory of Open Access Journals (Sweden)

Nádia Bruna da Silva Negrinho

Full Text Available RESUMO Objetivo: identificar os fatores associados à exposição ocupacional com material biológico entre profissionais de enfermagem. Método: estudo transversal, realizado em um hospital, de alta complexidade, do interior do Estado de São Paulo, Brasil. Foram entrevistados profissionais de enfermagem no período de março a novembro de 2015. Todos os aspectos éticos foram contemplados. Resultado: dentre 226 profissionais entrevistados, 17,3% sofreram exposição ocupacional com material biológico potencialmente contaminado, sendo 61,5% por via percutânea. Fatores, como a faixa etária (p=0,003, a experiência na enfermagem (p=0,015 e na instituição, (p=0,032 estiveram associados ao acidente. Conclusão: a maior parte dos acidentes com material biológico entre os profissionais de enfermagem ocorreu por via percutânea sendo que a idade, experiência profissional e na instituição compreenderam fatores associados à exposição ocupacional.

Study of continuous DOI positioning for solid-state PET detectors

International Nuclear Information System (INIS)

Lee, Chae Hun

2007-02-01

PET is a nuclear imaging technique that measures the spatial and temporal distribution of compounds labeled with a positron emitting radionuclide introduced into a subject to be determined non-invasively. Spatial resolution degradation occurs at the edge of Field Of View (FOV) due to parallax error. To improve spatial resolution at the edge of FOV, Depth-Of-Interaction (DOI) PET has been investigated and there are several methods for DOI positioning. Among DOI positioning methods, sharing scintillation light output is the cost-effective and accurate method while solid-state photosensors such as Avalanche Photodiodes have been well developed. Avalanche photodiodes have internal gain by impact ionizations in high electric field. High gain and low noise are good characteristics for use in PET. In this thesis, DOI-PET detector using two APD with LSO scintillation crystal was designed and evaluated, and parameter to affect DOI positioning was investigated. Energy resolution of the designed detector was 12 % in 662 keV photopeak. Comparing photopeak channels of two APD output, DOI position was measured. DOI positioning error was ±2.5 mm. DOI resolution in current DOI-PET systems is still ∼ cm. Minimum 4 step positions can be obtained with 2 cm long LSO crystal in this result

The Sub-Polar Gyre Index - a community data set for application in fisheries and environment research

DEFF Research Database (Denmark)

Berx, Barbara; Payne, Mark

2017-01-01

Scientific interest in the sub-polar gyre of the North Atlantic Ocean has increased in recent years. The sub-polar gyre has contracted and weakened, and changes in circulation pathways have been linked to changes in marine ecosystem productivity. To aid fisheries and environmental scientists, we...... series length are explored but found not to be important factors in terms of the SPG-I's interpretation. Our time series compares well with indices presented previously. The SPG-I time series is freely available online (http://dx.doi.org/10.7489/1806-1), and we invite the community to access, apply...

Comparação econômica entre controle biológico e químico para o manejo de ácaro-vermelho em macieira Economic comparison of biological and chemical control in the management of red spider mites in apple orchard

Directory of Open Access Journals (Sweden)

Lino Bittencourt Monteiro

2006-12-01

Full Text Available O ácaro-vermelho da macieira, Panonychus ulmi (Acari: Tetranychidae, é uma importante praga na cultura da macieira em Fraiburgo - SC, e o controle biológico aplicado foi implantado em meados dos anos 90. O objetivo deste trabalho foi demonstrar os benefícios econômicos da utilização do controle biológico no manejo do ácaro-vermelho. A avaliação foi realizada em dois pomares comerciais de macieiras. Em um deles, foi implantado o controle biológico aplicado de ácaros, baseado na liberação do ácaro predador Neoseiulus californicus (Acari: Phytoseiidae, seleção de inseticidas e manejo de ervas invasoras, e o outro pomar seguiu o manejo convencional de artrópodes, baseado na aplicação de produtos químicos para o controle de insetos, ácaros fitófagos e ervas invasoras. A análise econômica mostrou que os custos com mão-de-obra e máquinas foram semelhantes em ambos os pomares, entretanto os custos com acaricidas foram significativamente inferiores no pomar onde o manejo foi o controle biológico, demonstrando que, apesar da necessidade de investimentos em instalações para a criação do ácaro predador e custos de manutenção das mesmas, a estratégia biológica foi economicamente viável.Red spider mite, Panonychus ulmi (Acari: Tetranychidae is a significant pest in apple tree in Fraiburgo, Santa Catarina (SC and applied biological control was implemented in the mid-nineties. The objective of this study was to demonstrate the economic benefits of biological control in the management of red spider mite. The assessment was carried out in two commercial orchards, one of which was subjected to biological control of spider mite by releasing the predator Neoseiulus californicus, insecticide selection and weed management, and the other to conventional arthropod management, based on the application of chemicals to control insects, phytofagous mites and weed. Economic analysis showed that the costs for labor and machines were

Dois funcionalistas franceses em confronto

Directory of Open Access Journals (Sweden)

Rafael Eugenio Hoyos-Andrade

2001-02-01

Full Text Available

Comparamos, neste artigo, de modo aproximativo e provisório, dois modelos de análise sintática e dois métodos de representação gráfica dessas análises: trata-se dos modelos e métodos de André Martinet e Lucien Tesnière. Depois de algumas considerações introdutórias relativas ao funcionalismo dos autores em causa, arrolamos um conjunto de características que aproximam ou opõem os seus respectivos modelos. Apresentamos, em seguida, no intuito de beneficiar os estudantes universitários de sintaxe, as representações gráficas de um mesmo enunciado segundo o método estemático de Tesnière e segundo o método de visualização das relações sintáticas de Martinet, para concluir que os dois modelos/métodos, embora diferentes, poderiam eventualmente ser integrados num único sistema de análise e representação.

Poliquetos (Annelida: Polychaeta como indicadores biológicos de contaminación marina: casos en Colombia

Directory of Open Access Journals (Sweden)

Vanessa Fernández Rodríguez

2015-06-01

Full Text Available El concepto de Indicador Biológico ha sido usado sin mayor precaución al momento de emplear ciertos organismos en programas de monitoreo ambiental, lo cual genera confusión. Uno de los objetivos de este trabajo fue resaltar la importancia en la consolidación de una definición precisa de este concepto a partir de información disponible, proponiendo una definición para el mismo. Las características ecológicas de los poliquetos permiten que, al estar en contacto permanente con diferentes tipos de contaminantes, respondan bioacumulando, disminuyendo o aumentando su abundancia, según sea la especie, hecho que posiciona este tipo de organismos como potenciales indicadores de contaminación marina. En este artículo se presenta de manera concreta un análisis de la literatura disponible para poliquetos en el campo de los indicadores biológicos, resaltando cómo éstos han sido usados en diferentes metodologías, con ejemplos a internacionales, así como una selección especial para Colombia. De los resultados más sobresalientes se encontró que Capitella capitata es la especie más estudiada al estar asociada con ambientes contaminados a causa del incremento de materia orgánica y es la única especie reportada en el país como indicador biológico usando las técnicas clásicas de bioindicación. Finalmente, se reitera la importancia de iniciar investigaciones sobre los aspectos ecológicos, ecotoxicológicos y bioensayos de laboratorio con otras especies de poliquetos para validar cuáles especies y por qué pueden ser consideradas como indicadores biológicos para el país.

Ciclo de vida de Triatoma dimidiata Latreille, 1811 (Hemiptera, Reduviidae) en condiciones de laboratorio: producción de ninfas para ensayos biológicos

OpenAIRE

Marlene Reyes; Víctor Manuel Angulo

2009-01-01

Introducción. A pesar de la importancia de Triatoma dimidiata como vector de la enfermedad de Chagas, poco se conoce de su ciclo biológico y de la producción eficiente de insectos disponibles para ensayos biológicos. Objetivo. Determinar las características del ciclo de vida en el laboratorio y establecer las condiciones del estado nutricional para la producción eficiente de ninfas de V estadio para ensayos biológicos. Materiales y métodos. Se determinaron los tiempos de desarrollo de l...

Avaliação do processo de tratamento biológico de águas residuárias sanitária e industrial em sistema combinado com reator biológico de contato seguido de filtro aerado submerso

OpenAIRE

Hércules Antonio de Oliveira

2010-01-01

Este estudo apresenta os resultados da operação de uma planta piloto de tratamento biológico para águas residuárias, em testes realizados em duas fases de estudo, sendo a primeira relacionada com a operação de um reator biológico de contato (RBC) e a segunda com a operação em sistema combinado, com um biofiltro aerado submerso (BAS) à jusante do RBC. As unidades RBC e BAS foram ensaiadas no tratamento de esgoto sanitário. A vazão média de alimentação foi de 82,9 Lh-1, e vazão de recirculação ...

New DOI identification approach for high-resolution PET detectors

International Nuclear Information System (INIS)

Choghadi, Amin; Takahashi, Hiroyuki; Shimazoe, Kenji

2016-01-01

Depth-of-interaction (DOI) Identification in positron emission tomography (PET) detectors is getting importance as it improves spatial resolution in both conventional and time-of-flight (TOF) PET, and coincidence time resolution (CTR) in TOF-PET. In both prototypes, spatial resolution is affected by parallax error caused by length of scintillator crystals. This long length also contributes substantial timing uncertainty to the time resolution of TOF-PET. Through DOI identification, both parallax error and the timing uncertainty caused by the length of crystal can be resolved. In this work, a novel approach to estimate DOI was investigated, enjoying the interference of absorbance spectrum of scintillator crystals with their emission spectrum. Because the absorption length is close to zero for shorter wavelengths of crystal emission spectrum, the counts in this range of spectrum highly depend on DOI; that is, higher counts corresponds to deeper interactions. The ratio of counts in this range to the total counts is a good measure to estimate DOI. In order to extract such ratio, two photodetectors for each crystal are used and an optical filter is mounted only on top of one of them. The ratio of filtered output to non-filtered output can be utilized as DOI estimator. For a 2×2×20 mm 3 GAGG:Ce scintillator, 8-mm DOI resolution achieved in our simulations. (author)

Descrição da larva de último instar e pupa de Epacroplon cruciatum (Aurivillius (Coleoptera, Cerambycidae, Cerambycinae e notas biológica

Directory of Open Access Journals (Sweden)

Juares Fuhrmann

2012-03-01

Full Text Available Descrição da larva de último instar e pupa de Epacroplon cruciatum (Aurivillius (Coleoptera, Cerambycidae, Cerambycinae e notas biológicas. Último instar larval e pupa do Hexoplonini sul-americano Epacroplon cruciatum (Aurivillius, 1899 são descritos, ilustrados e disponibilizadas notas biológicas.

Evolução biológica: ECO-EVO-DEVO na formação inicial de professores e pesquisadores

Directory of Open Access Journals (Sweden)

Thais Benetti Oliveira

2017-07-01

Full Text Available A epistemologia é uma área que fornece aportes para reflexão sobre a natureza e construção dos conhecimentos. No que é referente às Ciências Biológicas, o conceito de evolução é entendido como um eixo integrador dessa Ciência e, portanto, deve representar a integração das diversas áreas da Biologia. Um estudo epistemológico sobre evolução permite que identifiquemos uma abordagem recente de pesquisa denominada ECO-EVO-DEVO, a qual apresenta um sincronismo entre desenvolvimento, organismo e ambiente no processo evolutivo e na constituição da diversidade fenotípica. Entendemos que é de ostensiva importância que essa abordagem seja discutia durante a Formação Inicial de professores e pesquisadores em Ciências Biológicas e, portanto, pretendemos investigar meios de representa-la como uma forma a facilitar sua inserção na sala de aula. Para a realização desta investigação, organizamos um Grupo de Pesquisa em Epistemologia da Biologia (GPEB onde foram propostas discussões acerca da evolução biológica a partir dessa abordagem. Desta forma, este artigo é sistematizado por meio de três principais eixos: 1 as características do conhecimento biológico integrado; 2 a epistemologia como parte fundamental à didática da biologia; 3 o GPEB como um espaço formativo por meio do qual pôde-se obter dados empíricos acerca de possibilidades de didatização do conhecimento biológico e 4 a proposição de diagramas para representar o percurso conceitual da abordagem integrada da evolução. Assim, um estudo aprofundado sobre as compilações contemporâneas acerca da ECO-EVO-DEVO e da pluralidade de processos que envolvem a evolução biológica, as discussões no GPEB e a elaboração de diagramas decorrentes da organização conceitual engendrada pelos participantes do grupo formam estratégias metodológicas que permitiram exemplificar caracterizações sobre a integração dos níveis biológicos no processo evolutivo

Contribución a la mejora del tratamiento biológico de aguas residuales de la industria de curtidos

OpenAIRE

Artiga Acuña, Priscila

2005-01-01

Os obxectivos desta Tese Doutoral son a mellora e a optimización dos procesos empregados no tratamento biolóxico das augas residuais na industria de curtidos, agrupándose os estudos feitos en tres etapas diferenciadas: 1) Posta a punto de novos sistemas de monitorización para o seguimento da actividade e toxicidade microbiana en sistemas de depuración biolóxicos, mediante sistemas de titulación; 2) Avaliación de estratexias para a mellora dos procesos convencionais de lamas ...

La biomonitorización de sustancias tóxicas en muestras biológicas de población general

OpenAIRE

Ibarluzea, Jesús; Aurrekoetxea, Juan José; Porta Serra, Miquel; Sunyer Deu, Jordi; Ballester Díez, Ferran

2016-01-01

La biomonitorización de sustancias tóxicas ha sido incorporada por buena parte de los países más desarrollados, con el objetivo de conocer sus concentraciones en muestras biológicas. Estas sustancias se incorporan al organismo por medio de diferentes exposiciones ambientales. La vigilancia en muestras biológicas debe permitir conocer sus valores en grupos vulnerables y su evolución en el tiempo, comparar con los valores observados en otros países, identificar grupos que presenten valores alto...

Did Oligocene crustal thickening precede basin development in northern Thailand? A geochronological reassessment of Doi Inthanon and Doi Suthep

Science.gov (United States)

Gardiner, Nicholas J.; Roberts, Nick M. W.; Morley, Christopher K.; Searle, Michael P.; Whitehouse, Martin J.

2016-01-01

The Doi Inthanon and Doi Suthep metamorphic core complexes in northern Thailand are comprised of amphibolite-grade migmatitic gneisses mantled by lower-grade mylonites and metasedimentary sequences, thought to represent Cordilleran-style core complexes exhumed through the mobilization of a low-angle detachment fault. Previous studies have interpreted two metamorphic events (Late Triassic and Late Cretaceous), followed by ductile extension between the late Eocene and late Oligocene, a model which infers movement on the detachment at ca. 40 Ma, and which culminates in a rapid unroofing of the complexes in the early Miocene. The Chiang Mai Basin, the largest such Cenozoic Basin in the region, lies immediately to the east. Its development is related to the extension observed at Doi Inthanon and Doi Suthep, however it is not definitively dated, and models for its development have difficulty reconciling Miocene cooling ages with Eocene detachment movement. Here we present new in-situ LA-ICP-MS and SIMS U-Pb age data of zircon and monazite grains from gneiss and leucogranite samples taken from Doi Inthanon and Doi Suthep. Our new zircon data exhibit an older age range of 221-210 Ma, with younger ages of ca. 72 Ma, and 32-26 Ma. Our monazite data imply an older age cluster at 83-67 Ma, and a younger age cluster of 34-24 Ma. While our data support the view of Indosinian basement being reworked in the Cretaceous, they also indicate a late Eocene-Oligocene tectonothermal event, resulting in prograde metamorphism and anatexis. We suggest that this later event is related to localized transpressional thickening associated with sinistral movement on the Mae Ping Fault, coupled with thickening at the restraining bend of the Mae Yuan Fault to the immediate west of Doi Inthanon. Further, this upper Oligocene age limit from our zircon and monazite data would imply a younger Miocene constraint on movement of the detachment, which, when combined with the previously recorded Miocene

Investigación sobre el efecto de la temperatura en los procesos biológicos por fangos activos

OpenAIRE

Francisco Díaz, Juan Pablo de

2003-01-01

Durante la presente Investigación se ha estudiado el efecto que produce la temperatura en los procesos de depuración biológica por fangos activos, desarrollando la influencia de dicho factor en cada una de las etapas de la línea de agua de una estación depuradora. - Pretratamiento - Decantación Primaria - Reactor Biológico - Decantación Secundaria Se ha considerado que los efectos de la temperatura en los procesos meramente físicos, son mínimos, únicamente provocados por la variación de la de...

Parâmetros biológicos e tabela de vida de fertilidade de Neopamera bilobata (Hemiptera: Rhyparochromidae em morangueiro

Directory of Open Access Journals (Sweden)

Taciana Melissa de Azevedo Kuhn

2014-06-01

Full Text Available O objetivo deste trabalho foi avaliar os parâmetros biológicos e determinar a tabela de vida de fertilidade de Neopamera bilobata (Hemiptera: Rhyparochromidae em morangueiro. O experimento foi realizado no Laboratório de Entomologia da Embrapa Uva e Vinho, em Bento Gonçalves, RS, em câmara climatizada (a 23±1°C, 70±10% UR e fotófase de 12 horas. Utilizaram-se folíolos, flores, frutos verdes e maduros de morangueiro 'Aromas' como alimento para os percevejos. O desenvolvimento das fases imaturas e os parâmetros biológicos dos adultos foram monitorados diariamente. O percevejo N. bilobata não completou o ciclo biológico em folíolos e flores de morangueiro. Em frutos maduros e verdes, o tempo de desenvolvimento da ninfa ao adulto foi de 32,8±9,12 e 36,7±6,80 dias, com viabilidade de 27,3 e 51%, respectivamente. O período de oviposição foi de 34,7±21,2 dias, com 319,1±262,7 ovos em frutos maduros, e de 43,9±18,3 dias, com 318,2±144,7 ovos em frutos verdes. Neopamera bilobata completa seu ciclo biológico na cultura do morangueiro. Frutos verdes de morangueiro são mais adequados ao desenvolvimento deste inseto do que frutos maduros.

Atribuição de significados biológicos às variáveis da equação logística: uma aplicação do Cálculo nas Ciências Biológicas Attribution of biological meanings to variables of logistic equation: applying Calculus to Biology

Directory of Open Access Journals (Sweden)

Lilian Akemi Kato

2009-01-01

Full Text Available Este artigo apresenta, como objetivo principal, uma proposta metodológica para o ensino do Cálculo nos cursos de Ciências Biológicas, que privilegia a atribuição de significados biológicos às variáveis e parâmetros que aparecem nos modelos matemáticos no estudo de dinâmica de populações. Utilizou-se, neste estudo, a equação logística como modelo matemático que caracteriza diversos tipos de crescimento populacional, além de apresentar outras complexidades do fenômeno biológico que podem ser melhor caracterizadas e explicadas por meio dos conceitos matemáticos relacionados ao Cálculo Diferencial. Entende-se que estas relações do Cálculo com as Ciências Biológicas contribuem para a compreensão de fenômenos biológicos complexos que podem ser explicados por equações matemáticas bastante simples.A methodological proposal for the teaching of Calculus in Biology courses is suggested. It would highlight the attribution of biological meanings to variables and parameters in mathematical models within the study of population dynamics. Logistic equations have been used as a mathematical model that characterizes several types of population growth and other complexities of the biological phenomenon which may be better explained through mathematical concepts related to Differential Calculus. Relationship between Calculus and Biology may contribute towards the comprehension of complex biological phenomena that may be explained through simple mathematical equations.

Investigation of a whole-body DOI-PET system

International Nuclear Information System (INIS)

Ohi, Junichi; Tonami, Hiromichi

2007-01-01

In this study, we were conducting basic research on a whole-body depth of gamma-ray interaction (DOI) positron emission tomography system which provides spatial resolution that is both high and uniform, and also minimizes costs. The detectors consist of double-layer 9x10 GSO/GSO phoswich crystal blocks, a light guide and two rectangular PMTs. Individual crystal sizes are 2.45x5.1x15 mm 3 , and each layer of crystal blocks has a different decay time. Many of the circuit boards used in our current conventional PET system (SET-3000G SHIMADZU Japan) have been optimized for DOI acquisition. The detectors are arranged to form a 332.5 mm radius detection ring, and spatial resolution is obtained from the center to the edge of the 250 mm radius field of view. The effect of DOI was confirmed using a comparison with the non-DOI systems

Aspectos étnicos, biológicos e químicos de Senna occidentalis (Fabaceae

Directory of Open Access Journals (Sweden)

T. M. KANEKO

2009-08-01

Full Text Available Senna occidentalis (sin. Cassia occidentalis é um arbusto perene nativo da América do Sul e distribuída em regiões tropicais ao redor do mundo, frequentemente contaminando pastos e culturas de cereais. Inúmeros estudos demonstraram que esta planta é tóxica para animais. Na medicina popular, tribos americanas, africanas e indianas usam preparações da S. occidentalis como tônico, estomáquico, febrífugo, laxante e antimicrobiano. Diversas propriedades biológicas da espécie já foram comprovadas, tais como a antibacteriana, antifúngica, antimalárica, antitumoral e hepatoprotetora. As análises fitoquímicas evidenciaram que as antraquinonas, os flavonóides e outros derivados fenólicos são os seus principais constituintes. Esta revisão apresenta dados etnofarmacológicos, químicos e biológicos publicados na literatura sobre S. occidentalis. Palavras-chave: Senna occidentalis. Cassia occidentalis. Fabaceae. Leguminosae. Caesalpinioideae. Fedegoso.

Disponibilidade de azoto para as plantas, a partir de fertilizantes orgânicos autorizados em agricultura biológica

OpenAIRE

Pereira, Anabela; Rodrigues, M.A.; Arrobas, Margarida

2005-01-01

Os fertilizantes orgânicos continuam a ser bastante valorizados pela agricultura. No modo de produção biológico, com as restrições ao uso de fertilizantes de síntese, os fertilizantes autorizados para aquele fim, ganham importância acrescida Neste trabalho reportam-se resultados de um ensaio que incluiu 8 tipos de fertilizantes, alguns dos quais autorizados em agricultura biológica. O trabalho está integrado numa linha de investigação mais ampla que envolve também ensaios de campo. Os fertili...

Resíduos biológicos nos Institutos de Medicina Legal de Goiás: implicações para os trabalhadores

Directory of Open Access Journals (Sweden)

Izildinha Pedreira Barros

2006-12-01

Full Text Available Os objetivos deste estudo foram identificar o manejo dos resíduos biológicos nos Institutos de Medicina legal, segundo as diferentes etapas previstas na legislação nacional vigente; verificar a situação de risco biológico ocupacional para os trabalhadores dos Institutos de Medicina Legal (IML do Estado de Goiás A coleta de dados foi realizada por meio de observação direta, entrevista e questionário com os trabalhadores. Apesar desses serviços gerarem resíduos semelhantes ao de qualquer instituição de saúde, estes não são segregados, acondicionados e dispostos conforme as normas legais vigentes. O manejo de perfurocortantes foi o principal risco para o trabalhador, gerando exposição percutânea. Embora, haja uma consciência, entre os trabalhadores, acerca do risco biológico envolvido em suas atividades, há baixa adesão às medidas de proteção. A maioria não usa os equipamentos de proteção individual recomendados, e não têm esquema completo para as vacinas contra o vírus da hepatite B e contra o tétano. Os resultados mostram a ausência de uma política voltada para o gerenciamento dos resíduos biológicos nos IML, a vulnerabilidade dos profissionais quanto aos riscos com material biológico e a premente necessidade de educação permanente em relação às medidas de biossegurança.

Resíduos biológicos nos institutos de medicina legal de Goiás: implicações para os trabalhadores

Directory of Open Access Journals (Sweden)

Izildinha Pedreira Barros

2006-12-01

Full Text Available Os objetivos deste estudo foram identificar o manejo dos resíduos biológicos nos Institutos de Medicina legal, segundo as diferentes etapas previstas na legislação nacional vigente; verificar a situação de risco biológico ocupacional para os trabalhadores dos Institutos de Medicina Legal (IML do Estado de Goiás A coleta de dados foi realizada por meio de observação direta, entrevista e questionário com os trabalhadores. Apesar desses serviços gerarem resíduos semelhantes ao de qualquer instituição de saúde, estes não são segregados, acondicionados e dispostos conforme as normas legais vigentes. O manejo de perfurocortantes foi o principal risco para o trabalhador, gerando exposição percutânea. Embora, haja uma consciência, entre os trabalhadores, acerca do risco biológico envolvido em suas atividades, há baixa adesão às medidas de proteção. A maioria não usa os equipamentos de proteção individual recomendados, e não têm esquema completo para as vacinas contra o vírus da hepatite B e contra o tétano. Os resultados mostram a ausência de uma política voltada para o gerenciamento dos resíduos biológicos nos IML, a vulnerabilidade dos profissionais quanto aos riscos com material biológico e a premente necessidade de educação permanente em relação às medidas de biossegurança.

FUNGOS MICORRÍZICOS ARBUSCULARES EM DOIS SISTEMAS DE CULTIVO DE MILHO

Directory of Open Access Journals (Sweden)

Amália Aparecida Busoni Campos

2015-07-01

Full Text Available Tendo em vista a utilização dos fungos micorrízicos arbusculares atuando como bioindicadores de qualidade do solo, o objetivo deste trabalho foi avaliar os efeitos sobre a porcentagem de colonização micorrízica, número de esporos viáveis e glomalina facilmente extraível de dois diferentes sistemas de cultivo de milho: milho transgênico em cultivo convencional e milho variedade em cultivo alternativo. Os tratamentos foram semeados em duas faixas paralelas e contíguas, com dois hectares cada, em condições semelhantes de fertilidade de solo e relevo. No cultivo convencional o milho transgênico foi semeado com adubação na linha de 280 kg.ha-1 do fertilizante fórmula NPK 7-28-16, 8% Ca, 1,5% S e 0,3% Zn. Foi utilizado glifosato juntamente com o inseticida Chlorantraniliprole + lambda-cialotrina para o controle de mato e lagartas. No cultivo alternativo o solo foi preparado com a aplicação de 500 kg.ha-1 do condicionador de solo Bokashi e posterior gradagem e nivelamento. Foi aplicado o herbicida atrazina para contenção do mato e uma pulverização de inseticida biológico (Bacillus thuringiensis para controle da lagarta do cartucho (Spodoptera frugiperda. A amostragem de raízes e solo foi feita na profundidade de 0 a 20 cm no estádio R3 (grão pastoso. Foi utilizado o delineamento em faixas de tratamento com dez repetições.  Os dados foram submetidos ao teste de normalidade de Shapiro-Wilk e as médias dos tratamentos comparadas pelo teste t de Student (P<0,05. Os resultados mostram maiores índices de colonização micorrízica e concentração de glomalina no solo no cultivo alternativo com milho variedade, comparado ao cultivo convencional com cultivar transgênico. Em relação ao número de esporos viáveis não houve diferença significativa entre os tratamentos. O milho variedade, submetido ao manejo alternativo, proporcionou melhores condições para o desenvolvimento dos fungos micorrízicos, indicando ser esta a

Entendendo o papel de marcadores biológicos no câncer de pulmão Understanding the role of biological markers in lung cancer

Directory of Open Access Journals (Sweden)

VERA LUIZA CAPELOZZI

2001-11-01

Full Text Available Marcadores biológicos são componentes celulares, estruturais e bioquímicos, que podem definir alterações celulares e moleculares tanto em células normais quanto aquelas associadas a transformação maligna. Podem ser de dois tipos: 1 marcadores intermediários, que medem alterações celulares e moleculares antes do aparecimento da malignidade; 2 marcadores diagnósticos, presentes em associação com a malignidade. O processo de identificação e validação para uso clínico do marcador tem diversas etapas: identificação inicial feita em linhagens celulares do tumor em questão; teste do marcador em tecido proveniente de biópsias de pacientes com diagnóstico estabelecido do tumor em questão; teste em biópsias de tecidos normais e com processo inflamatório; teste em escarro, sangue ou urina para validação como teste não-invasivo que possa ser usado em população de alto risco. Marcadores biológicos diagnósticos sorológicos e histológicos são componentes celulares, estruturais e bioquímicos, presentes não só em células tumorais como também em células normais, que podem ser medidos quantitativamente por métodos bioquímicos, imunológicos e moleculares nos fluidos ou nos tecidos corporais, respectivamente, associados a neoplasias e possivelmente ao órgão de origem da neoplasia. Marcadores biológicos são estudados em diferentes neoplasias primárias, porém poucos tiveram seu valor clínico definido. O papel dos marcadores biológicos em câncer de pulmão ainda é incerto, pois apenas um pequeno número de marcadores foi avaliado de maneira adequada. O objetivo deste trabalho é entender o papel dos marcadores biológicos sorológicos e diagnósticos no prognóstico e sobrevida de pacientes com câncer de pulmão baseado em uma coletânea de trabalhos realizada pela autora. Apresenta-se também uma perspectiva futura para a detecção precoce do câncer de pulmão baseada no papel dos marcadores biol

DOI in scientific journals of SciELO portal

OpenAIRE

Martín, Sandra Gisela

2013-01-01

Se presenta una descripción del portal de revistas científicas SciELO y del identificador DOI a través de su alcance, año de creación, historia, administración, normativa, estructura, ISBN-A y fuentes de consulta. Se brinda información acerca de la aplicación del DOI en las citas bibliográficas: en los estilos APA y Vancouver y en las normas ISO 690 (ISO, 2010) y ABNT 6023 (ABNT, 2002). El trabajo se propuso explorar el grado de implementación del DOI en las revistas científicas disponibles e...

Terapia biológica en enfermedades reumatológicas

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Manuel F Ugarte-Gil

2013-04-01

Full Text Available El advenimiento del uso de terapias biológicas en Reumatología ha modificado significativamente el pronóstico de pacientes portadores de artritis reumatoide (AR, artritis juvenil (AJ, espondilitis anquilosante (EA, entre otras enfermedades. A diferencia de las terapias convencionales estos productos biológicos se dirigen a los llamados blancos terapéuticos ya sea estas una línea celular, un mediador inflamatorio o un receptor de superficie. Estos compuestos son producidos por células vivas mediante la tecnología del ADN recombinante. Estos compuestos pueden tener componentes humano y animal [quiméricos (Xi, humanizados (Zu], o completamente humanos (H lo cual se reconoce por las letras que se incluyen en el nombre de cada uno. En el campo de la Reumatología, el primer compuesto utilizado fue el etanercept (anti-factor de necrosis tumoral o anti-TNF aprobado en 1998, pero otros anti-TNF han demostrado su beneficio en AR, como en EA y AJ. Los inhibidores de Interleucina (IL-1 casi no se usan en AR actualmente, pero si los inhibidores de IL-6, así como los agentes contra las células B y los agonistas de CTLA-4 (Cytotoxic T lymphocyte antigen. Existe asimismo un compuesto dirigido al BLyS (B-lymphocyte stimulator el cual se usa en lupus eritematoso sistémico y otro dirigido al receptor activador del factor nuclear κB (RANKL, receptor activator of nuclear factor-κB ligand que se usa en osteoporosis. Con el avance en el conocimiento de la patogenia de las enfermedades reumαticas, se vienen reconociendo otra blancos terapιuticas. En los aρos venideros, este campo ha de expandirse en proporciones geomιtricas

Ingestão de plástico pelo atobá-mascarado, Sula dactylatra Lesson, 1831, na Reserva Biológica do Atol das Rocas, RN, Brasil

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Erich de Freitas Mariano

2012-08-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2012v25n4p285   Partículas plásticas constituem um dos poluentes mais comuns no ambiente marinho e atingem inclusive regiões com baixa densidade populacional humana. Frequentemente, essas partículas são ingeridas por diversos organismos marinhos, ocasionando problemas no trato digestivo, que podem culminar no enfraquecimento e morte do animal. Em um estudo acerca da alimentação de 631 Atobás-mascarados, Sula dactylatra, na Reserva Biológica do Atol das Rocas, foram encontradas partículas plásticas no conteúdo estomacal de quatro indivíduos adultos. Os artefatos plásticos encontrados constituíam-se de um plástico transparente, um pedaço de rótulo de garrafa de água mineral, dois pedaços de plástico preto e um pedaço rígido pequeno e vermelho. O fluxo de embarcações, tanto pesqueiras quanto turísticas, no entorno da ReBio Atol das Rocas pode ser a fonte de origem das peças plásticas tanto nos conteúdos estomacais quanto os encontrados nas ilhas da reserva, evidenciando que ações antropogênicas já atingem áreas isoladas, as quais deveriam ter um elevado grau de proteção da biodiversidade. Diversas medidas podem ser tomadas para evitar eventos deletérios na biota marinha, porém há uma grande dificuldade em evitar o descarte de lixo proveniente de navios pesqueiros e de turismo, além dos materiais vindos do continente, sendo necessário um incremento nos esforços de conscientização e fiscalização.

A vivência dos trabalhadores de Enfermagem que sofreram acidente com fluido biológico: um olhar fenomenológico

OpenAIRE

Carolina Luiza Bernardes

2014-01-01

RESUMO A exposição ocupacional aos fluidos biológicos é inerente ao trabalho desempenhado pela equipe de enfermagem durante a realização da assistência, tornando o trabalhador susceptível a ocorrência de acidentes e exposto aos fluidos corporais que podem conter diferentes patógenos causadores de doenças como HIV, Hepatite B e C. Trata-se de um estudo de natureza qualitativa que objetivou compreender a experiência do acidente com fluido biológico e da assistência prestada aos trabalhadores de...

Fertilização biológica: técnicas de vanguarda para o desenvolvimento agrícola sustentável

OpenAIRE

Carvajal Muñoz, Juan Sebastián; Mera Benavides, Adriana Consuelo

2010-01-01

El empleo de fertilizantes biológicos ha crecido ostensiblemente en las últimas dos décadas. Tal utilización masiva surge como resultado de la amplia demanda de materia prima para los procesos productivos y abastecimiento de alimentos en el mundo. Los fertilizantes biológicos actúan como sustitutos de fertilizantes químicos tradicionales, brindan buenos rendimientos en las cosechas, favorecen el crecimiento de frutos sanos, resistentes al ataque de plagas y ofrecen facilidades para su aplicac...

Digital Object Identifier (DOI) – a must know for every author of ...

African Journals Online (AJOL)

It is a unique code preferred by publishers in the identification and exchange of the content of a digital object such as journal articles, web documents, or other intellectual property. This article is an eye opener to the features and benefits of DOI, anatomy of a DOI name, citing DOI in references and locating DOI of references.

Depuración de las aguas de lavado de aceitunas negras mediante procesos biológico aerobio y de ozonización

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García Rodríguez, Juan

2001-08-01

Full Text Available The purification of black olive washed waters has been studied by an aerobic biological treatment, an ozonation process and by the combination of both sequential processes: ozone-biological and biological-ozone. Biodegradation experiments have been carried out modifying the initial substrate and biomass concentration. In the ozonation experiments, temperature, pH and ozone partial pressure has been varied. A kinetic study applying the Contois’model to the biological experimental data was performed. In the ozonation process, supposing a firsts-order kinetic reaction with respect to COD and ozone, the kinetic constant was determined. In both combined treatments, the previous stage improved the reaction rate of the second stage. For the purification of these wastewaters, an aerobic biological treatment followed by an ozonation process was the most effective sequence.Se ha estudiado la depuración de las aguas de lavado del procesado de aceitunas negras por tratamientos biológico aerobio y de ozonización y por procesos combinados secuenciales ozono-biológico y biológico-ozono. Se han llevado a cabo experimentos de biodegradación modificando las concentraciones iniciales de sustrato y de biomasa. En los experimentos de ozonización se ha variado la temperatura, el pH y la presión parcial de ozono. Se ha realizado un estudio cinético aplicando el modelo de Contois a los procesos biológicos. Considerando reacciones de primer orden respecto de la DQO, se ha determinado la constante de velocidad en los procesos de ozonización. En los tratamientos combinados, la etapa previa supuso una mejora en la constante de velocidad de la segunda etapa. La secuencia depuración biológica aerobia seguida de ozonización resultó el proceso más eficaz para el tratamiento de estas aguas.

The Polar Rock Repository: Rescuing Polar Collections for New Research

Science.gov (United States)

Grunow, A.

2016-12-01

Geological field expeditions in polar regions are logistically difficult, financially expensive and can have a significant environmental impact on pristine regions. The scarcity of outcrop in Antarctica (98% ice-covered) makes previously collected rock samples very valuable to the science community. NSF recognized the need for preserving rock, dredge, and terrestrial core samples from polar areas and created the Polar Rock Repository (PRR). The PRR collection allows for full and open access to both samples and metadata via the PRR website. In addition to the physical samples and their basic metadata, the PRR archives supporting materials from the collector, field notebooks, images of the samples, field maps, air photos, thin sections and any associated bibliography/DOI's. Many of these supporting materials are unique. More than 40,000 samples are available from the PRR for scientific analysis to researchers around the globe. Most of the samples cataloged at the PRR were collected more than 30 years ago, some more than 100 years ago. The rock samples and metadata are made available online through an advanced search engine for the PRR website. This allows scientists to "drill down" into search results using categories and look-up object fields similar to websites like Amazon. Results can be viewed in a table, downloaded as a spreadsheet, or plotted on an interactive map that supports display of satellite imagery and bathymetry layers. Samples can be requested by placing them in the `shopping cart'. These old sample collections have been repeatedly used by scientists from around the world. One data request involved locating coal deposits in Antarctica for a global compilation and another for looking at the redox state of batholithic rocks from the Antarctic Peninsula using magnetic susceptibilities of PRR rocks. Sample usage has also included non-traditional geologic studies, such as a search for monopoles in Cenozoic volcanic samples, and remote sensing

Análises econômicas de modelos de produção com novilhas de corte primíparas aos dois, três e quatro anos de idade

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Pötter Luciana

2000-01-01

Full Text Available Este trabalho avaliou, por intermédio de simulações, a economicidade de sistemas de produção de bovinos de corte com novilhas primíparas aos dois (sistema "um ano", três (sistema "dois anos" e quatro anos (sistema "tradicional" de idade. No sistema "um ano", as fêmeas tiveram três sistemas nutricionais por 100 dias, após a desmama no primeiro outono-inverno, constituída por uma das três alternativas: a pastejo contínuo em pastagem cultivada de azevém - PAST; b pastejo contínuo em pastagem natural e suplementação com ração - CNR; c confinamento com silagem de sorgo + uréia - SIL. Após os 100 dias, as novilhas foram mantidas em conjunto, utilizando-se pastagens naturais melhoradas. Os modelos usados, para comparar os sistemas foram construídos em uma planilha de cálculo Excel, a partir de um modelo original. Os dados biológicos referentes ao sistema "um ano" foram coletados na Empresa Agropecuária Guatambu, Dom Pedrito, RS, em 395 bezerras de corte. A margem bruta anual correspondeu a R$ 44.066,99, R$ 41.001,32, R$ 40.509,86, R$ 40.045,65 e R$ 14.148,08, respectivamente, para os sistemas "dois anos", "um ano" SIL, "um ano" PAST, "um ano" CNR e "tradicional" de produção de bovinos de corte. O custo variável mais elevado foi do sistema "um ano" CNR. Sistemas de produção que fazem uso de tecnologias mais intensivas apresentam resultados superiores ao sistema "tradicional" de produção de bovinos de corte.

Observación de muestras biológicas al microscopio óptico

OpenAIRE

Alvarez Hornos, Francisco Javier; Izquierdo Sanchis, Marta

2013-01-01

La observación microscópica de muestras de aguas de los reactores biológicos de una Estación Depuradora de Aguas Residuales proporciona información cualitativa sobre la calidad de la población microbiana y del estado de los flóculos. En este vídeo, se muestra la utilización de un microscopio óptico para la observación de muestras de agua de un reactor de fangos activados. Data: 2013 ;

Carbon-free production of 2-deoxy-scyllo-inosose (DOI) in cyanobacterium Synechococcus elongatus PCC 7942.

Science.gov (United States)

Watanabe, Satoru; Ozawa, Hiroaki; Kato, Hiroaki; Nimura-Matsune, Kaori; Hirayama, Toshifumi; Kudo, Fumitaka; Eguchi, Tadashi; Kakinuma, Katsumi; Yoshikawa, Hirofumi

2018-01-01

Owing to their photosynthetic capabilities, there is increasing interest in utilizing cyanobacteria to convert solar energy into biomass. 2-Deoxy-scyllo-inosose (DOI) is a valuable starting material for the benzene-free synthesis of catechol and other benzenoids. DOI synthase (DOIS) is responsible for the formation of DOI from d-glucose-6-phosphate (G6P) in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics such as neomycin and butirosin. DOI fermentation using a recombinant Escherichia coli strain has been reported, although a carbon source is necessary for high-yield DOI production. We constructed DOI-producing cyanobacteria toward carbon-free and sustainable DOI production. A DOIS gene derived from the butirosin producer strain Bacillus circulans (btrC) was introduced and expressed in the cyanobacterium Synechococcus elongatus PCC 7942. We ultimately succeeded in producing 400 mg/L of DOI in S. elongatus without using a carbon source. DOI production by cyanobacteria represents a novel and efficient approach for producing benzenoids from G6P synthesized by photosynthesis.

Polarization measurement for internal polarized gaseous targets

International Nuclear Information System (INIS)

Ye Zhenyu; Ye Yunxiu; Lv Haijiang; Mao Yajun

2004-01-01

The authors present an introduction to internal polarized gaseous targets, polarization method, polarization measurement method and procedure. To get the total nuclear polarization of hydrogen atoms (including the polarization of the recombined hydrogen molecules) in the target cell, authors have measured the parameters relating to atomic polarization and polarized hydrogen atoms and molecules. The total polarization of the target during our measurement is P T =0.853 ± 0.036. (authors)

Investigação de acidentes biológicos entre profissionais de saúde Investigación de accidentes biológicos entre los trabajadores de la salud Investigation of biological accidents among health care workers

Directory of Open Access Journals (Sweden)

Juliana Azevedo da Silva

2009-09-01

Full Text Available Os objetivos deste trabalho foram identificar a principal categoria profissional exposta a risco biológico e os principais tipos de acidentes ocorridos entre trabalhadores da área de saúde, em Campos dos Goytacazes, RJ. A partir da análise das fichas de notificação de acidentes biológicos dos 183 profissionais acidentados entre janeiro de 2005 e setembro de 2005, observamos que a categoria profissional mais exposta foi a dos auxiliares/técnicos de enfermagem (54,1%, seguida pela dos acadêmicos de medicina e odontologia (10,4%. A ocorrência de acidentes com materiais perfurocortantes foi relacionada à manipulação frequente desses objetos e ao comportamento dos profissionais que utilizam práticas que oferecem riscos de acidentes com agulhas, tais como o descarte inadequado de objetos perfurocortantes.El objetivo de este estudio fue identificar las principales categorías profesional expuestas a riesgos biológicos y el principal tipo de accidentes producidos entre los profesionales del área de la salud en Campos dos Goytacazes, RJ. Del análisis de 183 archivos de los trabajadores que sufren accidentes con material biológico, de enero a septiembre de 2005, se observó que la categoría profesional más expuesta a sufrir accidentes fue el de los auxiliares de enfermería (54,1%, seguido por los estudiantes de odontología y medicina (10,4%. La de accidentes se relacionó con la manipulación frecuente de agujas, y con el comportamiento de los trabajadores, que mantienen prácticas que ofrecen riesgos, como la eliminación inadecuada de agujas.The aims of this study were to identify the major professional category exposed to biological risk and the principal type of accident occurred among health care workers in Campos dos Goytacazes, RJ. Based on the analysis of 183 records filled out by the workers who suffered biohazardous accidents between January 2005 and September 2005, we found the nursing auxiliaries and technicians as the

Las ciencias biológicas en el arte argentino contemporáneo

OpenAIRE

Matewecki, Natalia

2008-01-01

En este trabajo se describen las obras más recientes del arte argentino ligado a la ciencia y a la tecnología. Desde las producciones desarrolladas en el marco de la vida artificial que incluyen algoritmos evolutivos, algoritmos genéticos, autómatas celulares y robóticos, hasta los proyectos de bioarte que comprenden el uso de la biotecnología, todas estas obras marcan la pauta de un siglo caracterizado por el despliegue de las ciencias biológicas.

Producción de un tensoactivo biológico

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Rosero N. Gladys

2002-06-01

Full Text Available En este artículo se resume el estudio realizado en el Instituto Colombiano del Petróleo (ICP, para escalar desde el laboratorio hasta la planta piloto, un proceso para la producción de biosurfactante tipo ramnolípido. Mediante el examen de las condiciones de activación del microorganismo y del diseño del medio de cultivo se establecieron condiciones que en forma sistemática disparan el mecanismo productor del microorganismo y permiten incrementar la productividad del biosurfactante. Se demostró la alta eficiencia de este aditivo biológico en aplicaciones, tales como biodegradación de hidrocarburos en medios salinos, control de la corrosión y recuperación de crudo a partir de lodos de fondos de tanques de almacenamiento. 

Utilización de los equipos de protección individual frente al riesgo biológico por el personal sanitario

OpenAIRE

Angelina Constans Aubert; Rosa Mª Alonso Espadalé; Joaquín Pérez Nicolás

2008-01-01

El objetivo de este trabajo ha sido obtener información sobre el nivel de utilización de los equipos de protección individual (EPI) frente al riego biológico entre el personal que desarrolla su actividad profesional en centros sanitarios. Para ello se preparó un cuestionario, que previamente validado se aplicó a un colectivo de distintos centros sanitarios de Cataluña durante los años 2003/2004. La información obtenida en este estudio revela que la utilización de los EPI frente al riesgo biol...

Azeites de produção biológica e produção integrada: avaliação de critérios de qualidade Olive oil from organic agriculture and integrated production: quality parameters evaluation

Directory of Open Access Journals (Sweden)

C. J. M. Pintado

2007-01-01

Full Text Available Os olivais da Beira Baixa têm mostrado aptidão para evoluir para sistemas de agricultura sustentável, capazes de valorizar o ecossistema agrário, a sua biodiversidade, os seus produtos e o rendimento dos olivicultores, de que são exemplo os olivais em modo de produção biológico e em produção integrada. Neste trabalho efectuou-se o acompanhamento de olivais em modo de produção biológico e produção integrada, situados na Beira Baixa. A análise química das características dos azeites da cultivar Galega vulgar não revelou diferenças importantes entre os dois modos de produção, classificando-os na categoria “Azeite virgem extra”. Os resultados preliminares de um primeiro ano de ensaio revelaram que em ambos os sistemas de produção se obtiveram azeites com elevados padrões de qualidade.In Beira Baixa, organic and integrated protection olive grove management are considered as true alternatives and are seen by many as offering considerable benefits over other production systems, particularly with respect to sustainable development. Indeed, these agriculture systems can eradicate or minimize local negative environmental externalities and, simultaneously, bring better profits to the farmer and promote olive products safety. This study was undertaken to evaluate olive oil quality from organic and integrated protection agricultural systems. Analytical parameters of Galega olive oils were widely within European Union ruled limits, so the samples could be labelled “Extra virgin”. Olive oil obtained from both agricultural systems, organic and integrated protection, showed high quality standards.

Registro brasileiro de biológicos: processo de implementação e resultados preliminares do BiobadaBrasil Brazilian biologic registry: BiobadaBrasil implementation process and preliminary results

Directory of Open Access Journals (Sweden)

David C Titton

2011-04-01

Full Text Available OBJETIVOS: O presente estudo teve por objetivo descrever o processo de implementação de um registro nacional em um país em desenvolvimento (Brasil e relatar os principais resultados preliminares do registro BiobadaBrasil. MATERAL E MÉTODOS: Através de um acordo com a PANLAR, o protocolo Biobadaser foi utilizado como modelo para a implementação de um novo registro no nosso país. Durante os dois primeiros anos desse esforço, o protocolo original foi adaptado, traduzido e apresentado a todos os reumatologistas brasileiros. Durante dez meses, dados de 1.037 pacientes (750 tratados com biológicos e 287 controles de 15 centros foram coletados. RESULTADOS: A maioria dos pacientes tinha artrite reumatoide (AR (n = 723. Infliximabe foi o agente anti-TNF mais usado, e a exposição total a biológicos foi 2.101 pacientes-ano. A razão mais comum para suspensão da droga foi ineficiência ou perda de efetividade (50%, e 30% dos pacientes interromperam o tratamento devido a eventos adversos. Três casos de tuberculose foram observados no grupo biológico, representando maior incidência do que aquela da população brasileira geral. Infecções foram observadas em 23% dos pacientes do grupo biológico, sendo o trato respiratório superior o local mais comumente afetado. Apenas um caso de hanseníase tuberculoide foi observado. Nenhuma morte nem malignidade atribuível ao efeito dos medicamentos foi observada até fevereiro de 2010. CONCLUSÕES: A implementação do registro foi bem sucedida. Embora recente, o registro BiobadaBrasil já forneceu importantes dados.OBJECTIVES: The present study aimed at describing the implementation process of a national registry in a developing country (Brazil and at reporting the main preliminary results of the BiobadaBrasil registry. MATERIAL AND METHODS: Through a PANLAR agreement, the Biobadaser protocol was used as a model for implementing the new registry in our country. During the first two years of this

Consideraciones de diseño para la eliminación biológica de fósforo empleando procesos biopelícula

OpenAIRE

Castillo de Castro, Pedro; Tejero Monzón, Iñaki

1999-01-01

El siguiente artículo es un resumen del estado del arte de la Eliminación Biológica de Fósforo (EBF) empleando procesos de biopelícula. En él se describen minuciosamente los mecanismos que intervienen en la eliminación biológica de este elemento, así como las teorías actualmente aceptadas. Se presentan los procesos biopelícula actualmente desarrollados, así como los consideraciones de diseño para reactores biopelícula, y la forma de trabajo necesaria para conseguir la EBF.

Tratamiento biológico aerobio de alpechín depurado previamente con ozono

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Domínguez Vargas, Joaquín R.

2000-10-01

Full Text Available In the present work, the degradation of olive mill wastewaters previously treated by an ozonation stage has been studied by an aerobic biological oxidation. The substrate evolution (based on chemical oxygen demand, biomass (measured as volatile suspended solids and total polyphenolic contents were followed during each experiment. A kinetic study is performed by using the Contois model, which applied to the experimental data, provides the specific kinetic parameters of this model. The deduced kinetic equation for the consume of substrate is q= 17.0 S/(18.2 X + S0 X g COD/ gVSS. day. Moreover, others interesting biological parameters like the cellular yield coefficient and the kinetic rate constant for the endogenous metabolism were determined, obtaining a values of 0.214 g VSS/g COD and 0.167 day-1, respectively.En el presente trabajo se ha estudiado la oxidación biológica aerobia por Iodos activos de las aguas residuales de almazaras (alpechín que previamente habían sido depuradas por una etapa química mediante ozono. La evolución del proceso biológico fue seguida midiendo la concentración de sustrato (en términos de demanda química de oxígeno, la concentración de biomasa (medida como sólidos en suspensión volátiles y el contenido en compuestos polifenólicos totales. Se realiza un estudio cinético basado en el modelo de Contois que, aplicado a los datos experimentales, permite calcular los parámetros cinéticos específicos de este modelo. La ecuación deducida para el consumo de sustrato es q= 17.0 S/(18.2 X + S0 X, g DQO/ gSSV. día. Al mismo tiempo se han determinado otros parámetros biológicos de interés como son el coeficiente de rendimiento celular y la constante cinética correspondiente al metabolismo endógeno, obteniéndose unos valores de 0.214 g SSV/g DQO y 0.167 día-1, respectivamente.

Toxicidad biológica de cepas nativas de Bacillus thuringiensis Berliner en larvas de Tecia solanivora Povolny

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Paola Martínez

2011-11-01

Full Text Available La biodiversidad microbiológica de los suelos del departamento de Boyacá aún no ha sido explorada en toda su magnitud y existen microorganismos, como en el caso de Bacillus thuringiensis Berliner (Bt, que pueden emplearse para el desarrollo de estrategias biológicas de control de plagas en el futuro. Por lo anterior, el presente trabajo evaluó la actividad biológica, expresada como  toxicidad, de cepas nativas de B. thuringiensis en la Polilla Guatemalteca  de  la  papa  Tecia  solanivora Povolny, una de  las plagas más  limitantes en el cultivo de papa en la región andina colombiana. Esta  evaluación  se  realizó con  aislados de  Bt obtenidos y conservados por el Grupo de Manejo Biológico de Cultivos (GMBC en el Laboratorio de Control Biológico de la UPTC, colectados de muestras de  suelo en  la Provincia Centro de Boyacá y  previamente  caracterizados  macro  y microscópicamente.  La   toxicidad  se  evaluó mediante bioensayos con larvas de primer instar de  T.  solanivora,  utilizando  el método  decontaminación superficial de cubos de papa. Se evaluó  la mortalidad  ocho  días  después  de montado  el  bioensayo  y  se  determinó, igualmente,  la Concentración letal media (Cl 50 de las cepas que presentaron  la mayor actividad  tóxica en  los  bioensayos  iniciales.  Los  aislamientosGMBC-B054, GMBC-B071, GMBC-B076, GMBC- B098, GMBC-B111 y GMBC-B117 fueron  los más activos, con Cl 50 de 1.08x106, 4.24x106, 5.12x106, 4.36x103, 3.56x103  y  1.19x104  esporas  · mL-1,respectivamente.

Convection flow structure in the central polar cap

Science.gov (United States)

Bristow, W. A.

2017-12-01

A previous study of spatially averaged flow velocity in the central polar cap [Bristow et al., 2015] observed under steady IMF conditions found that it was extremely rare for the average to exceed 850 m/s (less than 0.2 % of the time). Anecdotally, however it is not uncommon to observe line-of-sight velocities in excess of 100 m/s in the McMurdo radar field of view directly over the magnetic pole. This discrepancy motivated this study, which examines the conditions under which high-velocity flows are observed at latitudes greater than 80° magnetic latitude. It was found that highly structured flows are common in the central polar cap, which leads to the flow within regions to have significant deviation from the average. In addition, the high-speed flow regions are usually directed away from the earth-sun line. No specific set of driving conditions was identified to be associated with high-speed flows. The study did conclude that 1)Polar cap velocities are generally highly structured. 2)Flow patterns typically illustrate narrow channels, vortical flow regions, and propagating features. 3) Persistent waves are a regular occurrence. 3)Features are observed to propagate from day side to night side, and from night side to day side.. 4)Convection often exhibits significant difference between the two hemispheres. And 5)About 10% of the time the velocity somewhere in the cap exceeds 1 Km/s The presentation will conclude with a discussion of the physical reasons for the flow structure. Bristow, W. A., E. Amata, J. Spaleta, and M. F. Marcucci (2015), Observations of the relationship between ionospheric central polar cap and dayside throat convection velocities, and solar wind/IMF driving, J. Geophys. Res. Space Physics, 120, doi:10.1002/2015JA021199.

2552-IJBCS-Article-Kokou Agbekonyi Agbodan

African Journals Online (AJOL)

hp

radicalaire des extraits des fruits de. Raphia gentiliana De Wild (Arecaceae). Int. J. Biol. Chem. Sci., 8(6): 2441-2451. DOI. : http://dx.doi.org/10.4314/ ijbcs.v8i6.7. Popovici I, Saykova I, Tylkowsky B. 2006. Evaluation de l'activité antioxydant des composés phénoliques par la réactivité avec le radical libre DPPH. Revue de.

Las armas biológicas. Perspectivas de futuro

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Nieva Machín

2014-05-01

Full Text Available La valoración de bajo riesgo de sufrir un ataque con armas biológicas realizada por la estrategia nacional de seguridad resulta errónea ya que España como miembro de la OTAN debería recoger en su estrategia nacional de seguridad del año 2013 esta amenaza ya considerada como tal por la OTAN en el año 2002. Para una valoración efectiva del nivel de esta amenaza resulta preciso considerar que esta ha trascendido el ámbito militar. En el presente artículo se presentará la vulnerabilidad de España derivaba de las políticas y protocolos de seguridad de carácter reactivo y no preventivo establecidas en España así como aspectos mutidimensionales que requieren un replanteamiento y mejoras acordes a una valoración de riesgo más precisa.

Nosso corpo nos pertence: a dialética do biológico e do social

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Karen Mary Giffin

1991-06-01

Full Text Available Este artigo visa situar a discussão do biológico e do social no interior da análise da condição feminina. Com o surgimento das análises feministas, a hegemonia anterior das explicações biológicas é substituída por uma ênfase na construção social da identidade feminina. O determinismo biológico é repudiado, mesmo quando a identificação da mulher com o corpo e com a natureza e seu status secundário são considerados como universais. Neste processo de reelaboração do objeto, o papel ideológico da ciência é apontado, na medida em que a dominação masculina na ciência e na sociedade acompanhou a tendência histórica que relegou a questão da mulher à esfera natural. Embora uma crescente apreciação da construção social da atividade científica em si impulsione o abandono da dicotomia biológico/social ao nível conceitual, as diferenças entre homem e mulher na esfera da reprodução continuam a atuar. É argumentado que análise da reprodução requer caracterização dos sexos como entidades biossociais em relacionamento, situados em contextos históricos específicos, e que, na sociedade moderna, a mulher é sujeita a uma dupla contradição reprodutiva.This article aims at reviewing the discussion of biological and social factors in the analysis of women's social condition. With the appearance of a feminist perspective, the dominance of earlier biologically-based explanations was substituted by an emphasis on the social construction of female identity. Even when women's identification with the body and with nature, and their secondary status, were considered universal, biological determinism was rejected. In this process of re-definition of the object of study, the ideological role of science was pointed out, since male dominance in science and society accompanied the historical tendency which relegated "the woman question" to the sphere of natural fact. Although growing awareness of the socially-constructed nature

Comparación visual de grandes jerarquías: El caso de las de taxonomías biológicas

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Liliana Sancho-Chavarría

2017-03-01

Full Text Available La visualización y el análisis de las taxonomías biológicas es un reto monumental: las taxonomías biológicas son voluminosas, pueden cambiar con el tiempo conforme la comunidad científica hace nuevos descubrimientos, la información taxonómica está dispersa en todo el mundo, está incompleta y existen diferentes versiones de las taxonomías ya que los científicos utilizan diferentes criterios de clasificación. Para entender y documentar mejor la biodiversidad, así como para apoyar su conservación, es necesario curar e integrar esta información. Es aquí donde la comparación de grandes jerarquías se convierte en una herramienta sumamente útil. Hasta el momento, la investigación sobre este tema incluye el estado del arte sobre la visualización de la información y técnicas de comparación de jerarquías, el desarrollo de una herramienta de visualización de jerarquías mediante la técnica de árboles de conos y la caracterización de las tareas del trabajo taxonómico que inducen cambios en las taxonomías. Se identificaron 10 tareas: identificar congruencia, identificar correcciones, identificar nuevos nodos, obtener una visión global de los cambios, resumir cambios, encontrar inconsistencias, aplicar filtros, obtener detalles, enfocarse y editar. La contribución de esta investigación es comparar y visualizar las taxonomías biológicas mediante la consideración sistemática de dicha caracterización de las tareas de los usuarios, lo cual es un enfoque novedoso para el desarrollo de propuestas de visualización en el dominio de taxonomías biológicas.

Occupational accidents involving biological material among public health workers Accidentes de trabajo con material biológico entre trabajadores de unidades de salud pública Acidentes de trabalho com material biológico entre trabalhadores de unidades de saúde pública

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Mônica Bonagamba Chiodi

2007-08-01

Full Text Available This descriptive research aimed to recognize the occurrence of work accidents (WA involving exposure to biological material among health workers at Public Health Units in Ribeirão Preto-SP, Brazil. A quantitative approach was adopted. In 2004, 155 accidents were notified by means of the Work Accident Communication (WAC. Sixty-two accidents (40% involved exposure to biological material that could cause infections like Hepatitis and Aids. The highest number of victims (42 accidents came from the category of nursing aids and technicians. Needles were responsible for 80.6% of accidents and blood was the biological material involved in a majority of occupational exposure cases. This subject needs greater attention, so that prevention measures can be implemented, which consider the peculiarities of the activities carried out by the different professional categories.La finalidad de esta investigación descriptiva con aproximación cuantitativa fue investigar la ocurrencia de accidentes de trabajo (AT con exposición a material biológico entre trabajadores de salud que actúan en Unidades de Salud Publica del Municipio de Ribeirão Preto-SP, Brasil. Se registraron, mediante la Comunicación de Accidente de Trabajo (CAT, 155 accidentes durante el año de 2004. En 62 de estos accidentes (40% ocurrió la exposición del trabajador a materiales biológicos que podrían causar infecciones como hepatitis y sida. Ante la proporcionalidad de las categorías expuestas, se observó un mayor número de víctimas en la categoría de auxiliares y técnicos de enfermería, con 42 accidentes. Las agujas fueron responsables por 80,6% de los accidentes y la sangre fue el material biológico involucrado en la mayoría de las exposiciones ocupacionales. El tema merece mayor atención para que medidas preventivas puedan ser implementadas, considerándose las peculiaridades de las actividades realizadas en las diferentes categorías profesionales.Pesquisa descritiva de

Choice of crystal surface finishing for a dual-ended readout depth-of-interaction (DOI) detector

International Nuclear Information System (INIS)

Fan, Peng; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Wei, Qingyang; Yao, Rutao

2016-01-01

The objective of this study was to choose the crystal surface finishing for a dual-ended readout (DER) DOI detector. Through Monte Carlo simulations and experimental studies, we evaluated 4 crystal surface finishing options as combinations of crystal surface polishing (diffuse or specular) and reflector (diffuse or specular) options on a DER detector. We also tested one linear and one logarithm DOI calculation algorithm. The figures of merit used were DOI resolution, DOI positioning error, and energy resolution. Both the simulation and experimental results show that (1) choosing a diffuse type in either surface polishing or reflector would improve DOI resolution but degrade energy resolution; (2) crystal surface finishing with a diffuse polishing combined with a specular reflector appears a favorable candidate with a good balance of DOI and energy resolution; and (3) the linear and logarithm DOI calculation algorithms show overall comparable DOI error, and the linear algorithm was better for photon interactions near the ends of the crystal while the logarithm algorithm was better near the center. These results provide useful guidance in DER DOI detector design in choosing the crystal surface finishing and DOI calculation methods. (paper)

Turismo en espacios naturales: oportunidades en el corredor biológico mesoamericano

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Miguel Panadero Moya

2002-01-01

Full Text Available El Corredor Biológico Mesoamericano es una iniciativa de los presidentes de los Estados centroamericanos para facilitar la integración subregional mediante estrategias fundamentadas en la singularidad e importancia ecológica de sus recursos naturales. Pretende implantar medidas que aseguren la conservación de estos recursos de forma compatible con el aprovechamiento socioeconómico de su potencial turístico. El territorio que lo integra se extiende por todo el istmo centroamericano y posee notables recursos naturales de alto valor ecológico y zonas de interés histórico-artístico con gran importancia cultural. Sus elementos, que se engarzan en una cadena de verdes eslabones de singular vegetación, constituyen reductos de indudable atractivo y aptitud para la práctica del turismo en la naturaleza. La incorporación a los circuitos internacionales de viajeros de este proyecto está limitada por las precarias características socioeconómicas de sus pobladores y por la debilidad de las infraestructuras y equipamientos turísticos de la mayoría de los países implicados en el proyecto. Crear un pasillo biológico en armonía con sus habitantes, en uno de los esfuerzos de conservación para el desarrollo más grande planteado hasta el momento, es la idea de sus promotores que, con esta iniciativa, se muestran participes de la lógica de la globalización.

Espectros biológicos florísticos de Campos Rupestres de afloramento e Campos Úmidos diferem entre si e em relação ao Espectro Biológico Normal de Raunkiaer. Floristic biological spectra of Rock outcrops and Wet grasslands differ between themselves and in relation to the Raunkiaer’s Normal Biological Spectrum.

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Natalia de Oliveira COSTA

2012-12-01

Full Text Available A distribuição de frequência de classes de formas de vida em uma flora, conhecida como espectro biológico florístico, varia em função das condições climáticas e edáficas em que as plantas se desenvolvem. Neste trabalho comparamos os espectros biológicos médios (n = 3 de equivalentes a Campo Rupestre de afloramento e a Campo Úmido no Estado de São Paulo na expectativa de encontrar diferenças significativas entre os dois tipos de comunidade. Os Campos Rupestres (G-corrigido = 23,41; p-valor = 0,0001 e os Campos Úmidos (G-corrigido = 80,34; p < 0,0001 diferiram do Espectro Biológico Normal de Raunkiaer, bem como diferenciaram-se entre si (χ2 = 24,23; p < 0,0001. Uma Análise de Correspondência Distendida separou Campos Rupestres de Campos Úmidos devido às maiores frequências de fanerófitos nos primeiros e de hemicriptófitos e terófitos nos últimos. Sugerimos como hipóteses que os micro-habitats favoráveis ao desenvolvimentode fanerófitos sejam mais comuns nos Campos Rupestres de afloramento do que nos Campos Úmidos, ocorrendo o contrário com os micro-habitats favoráveis aos hemicriptófitos. Esta forma de vida pode apresentar melhor ajustamento ao encharcamento do solo do que os caméfitos e geófitos. A estratégia de escape apresentada pelos terófitos seria pouco eficiente em Campos Rupestres de afloramento devido à escassez de solo para proteção das sementes. The frequency distribution of life forms in a flora, called floristic biological spectrum, varies according to the climatic and edaphic conditions under which plants grow. In this work we compared the average (n = 3 biological spectra of Rock outcrop and Wet grassland like communities in São Paulo state expecting to find significant differences between the two community types. Rock outcrops (G-corrected = 23.41; p-value = 0.0001 and Wet grasslands (G-corrected = 80.34; p < 0.0001 differed from the Raunkiaer’s Normal Biological Spectrum, as did between

Satisfação conjugal e parentalidade biológica e adoptiva

OpenAIRE

Ferreira, Júlia Maria de Araújo

2008-01-01

Tese de mestrado, Psicologia (Psicologia Clínica e da Saúde - Núcleo de Psicologia Clínica Sistémica), 2008, Universidade de Lisboa, Faculdade de Psicologia e de Ciências da Educação O presente estudo, pretendendo uma comparação entre famílias portuguesas biológicas e adoptivas, tem como objectivo analisar a percepção de Satisfação Conjugal e a sua respectiva influência nos Estilos Parentais praticados, com o intuito de compreender a teia de relações existente entre os domínios da Conjugal...

Aislamiento de microorganismos para control biológico de Moniliophthora roreri

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Liliana Yanet Suárez Contreras

2013-12-01

Full Text Available Moniliophthora roreri es un hongo que causa la moniliasis, una enfermedad de la mazorca en el cultivo de cacao (Theobroma cacao, con pérdidas hasta del 60% de la cosecha. El control biológico utilizando microorganismos endófitos surge como una alternativa para el manejo de esta enfermedad. En la presente investigación se evaluaron microorganismos con potencial para control biológico de M. roreri en Norte de Santander, Colombia. Para el efecto, se aisló e identificó este fitopatógeno y se utilizaron protocolos de desinfección de los posibles microorganismos antagonistas con siembras por diluciones seriadas, selección de los géneros microbianos con mayor potencial antagónico y evaluación de las cepas por la prueba de plato dual para evaluar el efecto biocontrolador de los hongos y la antibiosis para bacterias. Se tomaron muestras en los municipios de Cúcuta, Sardinata, El Tarra, Tibú y El Zulia, de las cuales se aislaron 17 cepas del fitopatógeno y 20 entre hongos y bacterias. De éstas se seleccionaron cuatro cepas de hongos y tres de bacterias por su capacidad antagónica contra M. roreri. Los mejores porcentajes de inhibición de crecimiento radial (PICR se alcanzaron con Paecilomyces sp. (HC002 vs M. roreri, con una media de 80.72%, seguido del tratamiento con Paecilomyces sp. (HZ002 vs M. roreri con 79.45%. Se demostró que el hongo Paecilomyces sp. también tiene un alto potencial antagónico in vitro frente a M. roreri. Al evaluar la antibiosis de las bacterias aisladas, se encontró que Bacillus brevis (BZ005 fue la más efectiva en todos los sitios del estudio, con porcentajes superiores a 89%.

Birds of the Reserva Biológica do Mato Grande and surroundings, Rio Grande do Sul, Brazil

DEFF Research Database (Denmark)

Vizentin-Bugoni, Jeferson; Jacobs, Fernando; Coimbra, Marco Antônio Afonso

2015-01-01

The Reserva Biológica do Mato Grande encompasses 5,161 hectares of wetlands, restinga forests and grasslands in southern Brazil. Aiming to assemble a list of bird species occurring in the reserve, we carried out 21 monthly expeditions from July 2007 to March 2009 and an additional visit on October...

Estándares de fermentación y maduración artesanal de Bioles

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Tulio Orellana

2016-06-01

Full Text Available Esta investigación, tuvo como objetivo principal establecer indicadores de calidad en el proceso  de  fermentación  anaerobia  de  bioles  de producción  local  y  conocer  sus principales  componentes   químicos. Se  realizó  la  determinación  periódica   de  los parámetros  físico químicos  "in  situ"  y  en  laboratorio,  luego  se realizó  un  tamizaje químico,  evaluándose  además  su  actividad fertilizante  mediante  la determinación  de macro  y  micronutrientes.  Se  observó  que  los bioles  con  bioactivad  presentan  los siguientes intervalos de confianza en sus parámetros físico-químicos: pH entre 3,4 y 4,6; conductividad  entre  16,2 y  23,84  mS/cm;  densidad  entre  1,030 y 1,060 Kglm3. El tamizaje químico permitió determinar de forma preliminar la presencia de los siguientes grupos químicos: alcaloides, terpenos/esteroides, quinonas, fenoles y taninos, entre otros, algunos de los cuales han sido asociados a su actividad antimicrobiana y promotora del crecimiento vegetal, constituyendo estos resultados los primeros generados en el país sobre el estudio de bioles de producción local, permitiendo el diseño de una metodología útil para la evaluación de otros bioinsumos de uso agrícola. Para el análisis estadístico del proceso de producción, se obtuvo un modelo de regresión polinómica de fado dos, para cada variable;  además del coeficiente de determinación del modelo (R-. También  se analizó la tendencia central y dispersión de las variables (parámetro de calidad, a través del promedio y la desviación estándar en el proceso y producto terminado.

Utilização de carvão ativado biológico para o tratamento de água para consumo humano

OpenAIRE

Westphalen,Ana Paula Campos; Corção,Gertrudes; Benetti,Antônio Domingues

2016-01-01

RESUMO: Este artigo de revisão aborda o uso do carvão ativado biológico no tratamento das águas para consumo humano. O tratamento biológico tem aplicação na redução da instabilidade da água potável causada por matéria orgânica biodegradável e compostos inorgânicos reduzidos presentes em baixas concentrações. A instabilidade tem efeitos prejudiciais à qualidade da água potável, tais como o crescimento de bactérias e a formação de biofilmes na rede de distribuição. O artigo discute as causas e ...

Oscilações entre o reducionismo e o fisicalismo não-redutivo no naturalismo biológico de John Searle

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Tárik de Athayde Prata

2013-08-01

Full Text Available O artigo examina a concepção de Searle sobre a redução da consciência (em especial a sua teoria acerca de seus poderes causais, que se mostra obscura e incoerente. Porém, essa incoerência não é inevitável, pois o naturalismo biológico possui elementos que permitiriam a articulação de uma teoria mais clara a respeito das capacidades causais. O exame da teoria de Pereboom e Kornblith possibilita entender por que a afirmação de identidade das capacidades causais leva a um reducionismo. Essa teoria aponta um caminho promissor para que se possa aprimorar o naturalismo biológico.

A Model for Data Citation in Astronomical Research Using Digital Object Identifiers (DOIs)

Science.gov (United States)

Novacescu, Jenny; Peek, Joshua E. G.; Weissman, Sarah; Fleming, Scott W.; Levay, Karen; Fraser, Elizabeth

2018-05-01

Standardizing and incentivizing the use of digital object identifiers (DOIs) to aggregate and identify both data analyzed and data generated by a research project will advance the field of astronomy to match best practices in other research fields like geoscience and medicine. An increase in the use of DOIs will prepare the discipline for changing expectations among funding agencies and publishers, who increasingly expect accurate and thorough data citation to accompany scientific outputs. The use of DOIs ensures a robust, sustainable, and interoperable approach to data citation in which due credit is given to the researchers and institutions who produce and maintain the primary data. We describe in this work the advantages of DOIs for data citation and best practices for integrating a DOI service in an astronomical archive. We report on a pilot project carried out in collaboration with AAS journals. During the course of the 1.5-year long pilot, over 75% of submitting authors opted to use the integrated DOI service to clearly identify data analyzed during their research project when prompted at the time of paper submission.

Utilização de carvão ativado biológico para o tratamento de água para consumo humano

Directory of Open Access Journals (Sweden)

Ana Paula Campos Westphalen

Full Text Available RESUMO: Este artigo de revisão aborda o uso do carvão ativado biológico no tratamento das águas para consumo humano. O tratamento biológico tem aplicação na redução da instabilidade da água potável causada por matéria orgânica biodegradável e compostos inorgânicos reduzidos presentes em baixas concentrações. A instabilidade tem efeitos prejudiciais à qualidade da água potável, tais como o crescimento de bactérias e a formação de biofilmes na rede de distribuição. O artigo discute as causas e consequências da instabilidade, as medidas de avaliação da matéria orgânica, os mecanismos de formação e controle de biofilmes no carvão ativado granular e as técnicas de avaliação microbiológica e da biodiversidade nos biofilmes. Além disso, analisa-se também a integração do carvão ativado biológico com outros processos usados no tratamento de água para consumo humano.

Contribuições de componentes da licenciatura em Ciências Biológicas na constituição do educador ambiental

Directory of Open Access Journals (Sweden)

Gabriela de Vargas de Rosa

2015-12-01

Full Text Available A educação ambiental é uma construção histórica de valores e responsabilidades, num processo de mudanças de atitudes quanto a relação ser humano e natureza, considerando a vida em sociedade. O objetivo do trabalho é verificar a contribuição da formação profissional na Licenciatura em Ciências Biológicas para a constituição do educador ambiental, numa perspectiva interdisciplinar do conhecimento. Para tanto, foram realizadas as análises das ementas e referências dos componentes curriculares Ecologia, Prática de Ensino I: Fundamentos teóricos e práticos em ciências e Prática de ensino VI: Prática de Pesquisa Biológica inscritos no Projeto Pedagógico do Curso de Ciências Biológicas da Universidade Regional do Noroeste do Estado do Rio Grande do Sul (UNIJUI, implantado em 2009. As discussões propiciadas a partir deste conhecimento, em sala de aula, proporcionam espaços de reflexão sobre a responsabilidade individual e coletiva na mudança de atitude quanto a relação com o ambiente.

Aspectos fundamentais na validação do monitor biológico para a esterilização por óxido de etileno

OpenAIRE

Terezinha de Jesus Andreoli Pinto

1991-01-01

Considerando a importância da garantia de esterilidade em produtos médico-hospitalares, e conhecendo a necessidade de controle do processo esterilizante por óxido de etileno através de vários parâmetros dentre eles pelo sensor biológico, este trabalho teve como objetivo a padronização de alguns aspectos importantes do monitor biológico. Esporos de Bacillus subtilis var. niger foram obtidos em meios sólido e líquido sintético de esporulação, assim como adquiridos no comércio nacional, como sus...

Substrats biològics de la conducta agressiva: Genètica i Neuroanatomia

OpenAIRE

Martí Carbonell, Sunsi

1984-01-01

En este trabajo se exponen los resultados obtenidos por un gran número de investigadores que han intentado explicar cómo intervienen los diferentes substratos biológicos en la agresión. Nos hemos centrado aquí en los substratos genético y neuroanatómico, y en un trabajo posteirior expondremos los substratos neuroquímico y hormonal. This paper is a review of the works dailing with the biological substrate of aggression with special referece to genetic and neuroanatomical findings. In a next...

Actividad biológica de los aceites esenciales de Acmella ciliata (Kunth) Cass

OpenAIRE

Rincón Mejía, Carlos Andrés; Castaño Osorio, Jhon Carlos; Ríos Vázquez, Eunice

2012-01-01

Introducción: Acmella ciliata (Kunth) Cass. es una arvense nativa del norte de Suramérica conocida por su contenido de alcamidas alifáticas, se usa popularmente como anestésico y analgésico contra los dolores de muelas y de garganta. Objetivos: obtener, analizar y evaluar la actividad biológica de los aceites esenciales de las flores y hojas de Acmella ciliata (Kunth) Cass. Métodos: se obtuvieron los aceites esenciales de Acmella ciliata por hidrodestilación e hidrodestilación asistida por mi...

10.5402 | dx.doi.org

Indian Academy of Sciences (India)

Home; public; Volumes; pram; 082; 01; dx.doi.org; 10.5402; 2012; 631504.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th ...

Performance of a DOI-encoding small animal PET system with monolithic scintillators

International Nuclear Information System (INIS)

Carles, M.; Lerche, Ch.W.; Sánchez, F.; Orero, A.; Moliner, L.; Soriano, A.; Benlloch, J.M.

2012-01-01

PET systems designed for specific applications require high resolution and sensitivity instrumentation. In dedicated system design smaller ring diameters and deeper crystals are widely used in order to increase the system sensitivity. However, this design increases the parallax error, which degrades the spatial image resolution gradually from the center to the edge of the field-of-view (FOV). Our group has designed a depth of interaction(DOI)-encoding small animal PET system based on monolithic crystals. In this work we investigate the restoration of radial resolution for transaxially off-center sources using the DOI information provided by our system. For this purpose we have designed a support for point like sources adapted to our system geometry that allows a spatial compression and resolution response study. For different point source radial positions along vertical and horizontal axes of a FOV transaxial plane we compare the results obtained by three methods: without DOI information, with the DOI provided by our system and with the assumption that all the γ-rays interact at half depth of the crystal thickness. Results show an improvement of the mean resolution of 10% with the half thickness assumption and a 16% achieved using the DOI provided by the system. Furthermore, a 10% restoration of the resolution uniformity is obtained using the half depth assumption and an 18% restoration using measured DOI.

Aspectos biológicos de Microcharops anticarsiae (Hymenoptera: Ichneumonidae) parasitando Anticarsia gemmatalis (Lepidoptera: Erebidae)

OpenAIRE

Aguirre-Gil, Oniel Jeremías [UNESP

2016-01-01

Microcharops anticarsiae é um eficiente parasitoide da lagarta-dasoja Anticarsia gemmatalis que, também, parasita lagartas de outras espécies como Chrysodeixis includens e Spodoptera eridania. O objetivo do trabalho foi (1) determinar o ínstar larval de A. gemmatalis preferencialmente parasitado por M. anticarsiae a partir de lagartas coletadas em campo, (2) determinar o efeito de criações sucessivas de M. anticarsiae nos parâmetros biológicos do parasitoide e (3) determinar o efeito da soja ...

Polarization of lanthanum nucleus by dynamic polarization method

International Nuclear Information System (INIS)

Adachi, Toshikazu; Ishimoto, Shigeru; Masuda, Yasuhiro; Morimoto, Kimio

1989-01-01

Preliminary studies have been carried out concerning the application of a dynamic polarization method to polarizing lanthanum fluoride single crystal to be employed as target in experiments with time reversal invariance. The present report briefly outlines the dynamic polarization method and describes some preliminary studies carried out so far. Dynamic polarization is of particular importance because no techniques are currently available that can produce highly polarized static nucleus. Spin interaction between electrons and protons (nuclei) plays a major role in the dynamic polarization method. In a thermal equilibrium state, electrons are polarized almost completely while most protons are not polarized. Positively polarized proton spin is produced by applying microwave to this system. The most hopeful candidate target material is single crystal of LaF 3 containing neodymium because the crystal is chemically stable and easy to handle. The spin direction is of great importance in experiments with time reversal invariance. The spin of neutrons in the target can be cancelled by adjusting the external magnetic field applied to a frozen polarized target. In a frozen spin state, the polarity decreases slowly with a relaxation time that depends on the external magnetic field and temperature. (N.K.)

Polarized neutrons

International Nuclear Information System (INIS)

Williams, W.G.

1988-01-01

The book on 'polarized neutrons' is intended to inform researchers in condensed matter physics and chemistry of the diversity of scientific problems that can be investigated using polarized neutron beams. The contents include chapters on:- neutron polarizers and instrumentation, polarized neutron scattering, neutron polarization analysis experiments and precessing neutron polarization. (U.K.)

Características biológicas del tejido adiposo: el adipocito como célula endocrina

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Reyes J. Marcela, Dra.

2012-03-01

Full Text Available La obesidad se caracteriza por un aumento de la masa adiposa secundaria a un balance energético positivo mantenido en el tiempo. El incremento en el volumen del tejido adiposo se acompaña de otros cambios en las características biológicas habituales de éste, que se vuelve disfuncional. El depósito visceral de la grasa, la hipertrofia y cambio del perfil secretor de los adipocitos, junto con la infiltración del tejido adiposo por células inflamatorias son algunas de las características que determinan una comunicación alterada del tejido adiposo con otros órganos. Se ha planteado que la disfunción del tejido adiposo, explicaría parte de la etiopatogenia de las enfermedades metabólicas y cardiovasculares asociadas a obesidad; sujetos obesos que mantienen un tejido adiposo funcional no presentan las alteraciones metabólicas propias de la malnutrición por exceso. La modulación de las características biológicas del tejido adiposo permitiría tener un menor riesgo cardiovascular asociado a obesidad.

Grupos substitutos, correspondência de assembléias aquáticas em relação a esquemas de classificação regional, e determinantes de diversidade beta em uma planície de inundação neotropical

OpenAIRE

PADIAL, André Andrian

2010-01-01

Um objetivo geral em Ecologia é entender como as comunidades estão organizadas no espaço e no tempo. Um aspecto de grande interesse para conservação é avaliar as similaridades na estrutura espacial e temporal da composição de diferentes grupos biológicos que habitam um mesmo ecossistema. Utilizando a abordagem de grupos substitutos, se dois grupos biológicos apresentam estrutura espacial/temporal similar, apenas um desses grupos concordantes poderia ser avaliado em esforços de ...

Uveomeningencefalites: registro de dois casos

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Wilson Luiz Sanvito

1982-03-01

Full Text Available Após considerações a propósito das manifestações clínicas das uveomeningencefalites, são relatados dois casos com características clínicas ligeiramente diferentes. No caso 1 tratava-se da doença de Harada, tendo o paciente apresentado quadro meningítico agudo acompanhado de confusão mental. O exame do líquido cefalorraquidiano evidenciou um quadro inflamatório do tipo linfo-monocitário e o paciente evoluiu com distúrbios acentuados da memória e uveíte bilateral. Após alguns meses de evolução, a doença deixou como seqüelas uma síndrome de Korsakoff e ambliopia acentuada no olho esquerdo. No caso 2 tratava-se de doença de Behcet, tendo o paciente apresentado dois surtos de meningite do tipo linfomonocitário, lesões herpetiformes na genitalia e uveíte no olho direito que evoluiu para amaurose. São feitas considerações sobre os aspectos etiopatogênicos destas afecções e sobre o controvertido uso dos corticosteróides em seu tratamento.

Factores de riesgo para el desarrollo psicomotor en lactantes nacidos en óptimas condiciones biológicas Risk factors for psychomotor development among infants born under optimal biological conditions

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Isidora de Andraca

1998-04-01

Full Text Available OBJECTIVO: Evaluar el efecto de factores de riesgo para el desarrollo infantil en niños, de nivel socioeconómico bajo, nacidos en óptimas condiciones biológicas pero expuestos a condiciones sociales adversas. METODOLOGÍA: Lactantes de ambos sexos em número de 788, fueron exhaustivamente estudiados en términos de: alimentación, crecimiento, ambiente físico y psicosocial. Se controlaron prospectivamente hasta los 12 meses de edad, momento en que se evaluó el desarrollo mental (MDI y motor (PDI a través de la escala de Bayley. A partir de las variables medidas se identificó 18 factores de riesgo, los que fueron dicotomizados (bajo y alto riesgo. RESULTADOS: Lactancia materna, temperamento del niño, inteligencia materna y estimulación en el hogar se asocian consistentemente con MDI y PDI. Luego de ajustar por covariables, la estimulación en el hogar persiste como factor significativo en la explicación de la variabilidad del MDI y PDI, en tanto que el sexo del niño se consolida como factor condicionante del desarrollo motor. El efecto acumulado de 7 o más factores de riesgo se asocia con una disminución significativa de los puntajes de desarrollo. La combinación de categorías de riesgo de temperamento infantil, inteligencia materna, rol del padre y estimulación en el hogar alcanza mejor predicción del desarrollo infantil que otras combinaciones puestas a prueba en este estudio. CONCLUSIONE: Se concluye que, aún en niños biológicamente indemnes, el desarrollo psicomotor se afecta negativamente ante la presencia de condiciones ambientales adversas que actúan simultáneamente.OBJETIVO: Avaliar o efeito dos fatores de risco para o desenvolvimento infantil em crianças de n��vel socioeconômico baixo, nascidos em ótimas condições biológicas, mas expostos a condições sociais adversas. METODOLOGIA: Lactentes dos dois sexos, no total de 788, foram exaustivamente estudados quanto a alimentação, crescimento, ambiente f

El pelo como matriz biológica alternativa y su uso en la determinación de la exposición intraútero a drogas ilícitas y fármacos

OpenAIRE

Lendoiro Belío, Elena

2016-01-01

El uso de matrices biológicas alternativas en el ámbito de la Toxicología Clínica y Forense se ha incrementado de forma significativa en los últimos años, ay que complementan la información obtenida por las matrices biológicas tradicionales. El pelo es una matriz biológica alternativa muy útil debido a su amplia ventana de detección, de meses o incluso años, que permite realizar el estudio retrospectivo del consumo y establecer el perfil cronológico del mismo. Sin embargo, para su análisis to...

Study of DOI resolution and imaging resolution of a PET device

International Nuclear Information System (INIS)

Saha, Lipika; Saitoh, Kazumi; Kobayashi, Shigeharu

2004-01-01

As a recent trend of DOI measurement for the PET, a simple method of utilizing the light attenuation properties of scintillation materials has been paid attention. We have studied the DOI resolutions for less expensive materials as BGO in both the bench test and the simulation by GEANT4.0. By comparison with both the results, we have recognized the importance of removing the multiple Compton absorption events to obtain the better DOI information. The simulation results for the imaging resolution suggested that its deterioration attributes to the parallax error as well as the systematic displacement inherent in the present method of 3D-reconstruction

A determinação biológica dos transtornos mentais: uma discussão a partir de teses neurocientíficas recentes

Directory of Open Access Journals (Sweden)

Luna Rodrigues Freitas-Silva

2016-01-01

Full Text Available Resumo: A compreensão dos processos de formação dos transtornos mentais vem se mostrando desafiadora desde a fundação do campo psiquiátrico. O desenvolvimento das neurociências proporcionou novo fôlego à expectativa de encontrar estritamente no funcionamento biológico a explicação para o surgimento dos transtornos mentais. No entanto, tal objetivo não vem sendo alcançado com a esperada facilidade, de modo que novas hipóteses começam a se destacar nas pesquisas neurocientíficas. Neste artigo, identificamos as noções de epigenética, neurodesenvolvimento e plasticidade como os principais indicativos de um novo modo de compreender a biologia dos fenômenos mentais. A complexidade genética, o papel formativo do ambiente e as variações que caracterizam a vulnerabilidade implicam importantes modificações nas principais teses sobre a determinação biológica dos transtornos mentais, sugerindo uma reconfiguração dos limites entre o "social" e o "biológico" nas pesquisas em neurociências.

Efeito da idade de Trichogramma exiguum e do desenvolvimento embrionário da Traça-das-Crucíferas sobre as características biológicas do parasitóide - DOI: 10.4025/actascibiolsci.v29i2.522 Effect of the age of Trichogramma exiguum and diamondback moth embryonic development on the biological characteristics of the parasitoid - DOI: 10.4025/actascibiolsci.v29i2.522

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Cácia Leila Tigre Pereira

2007-12-01

Full Text Available Este trabalho teve como objetivo avaliar a influência do desenvolvimento embrionário dos ovos do hospedeiro P. xylostella sobre fêmeas de Trichogramma exiguum, com diferentes idades. Para tanto, cinquenta fêmeas recém-emergidas ou com 24, 48, 72, e 96 horas após a emergência deste parasitóide foram divididas em cinco lotes. Para cada fêmea, foi oferecida uma cartela, contendo 30 ovos de P. xylostella com um, dois e três dias de idade. As maiores taxas de parasitismo foram observadas em ovos de três dias de desenvolvimento embrionário, independente da idade do parasitóide, com exceção daqueles com 72 horas de idade. A viabilidade não foi influenciada pela idade do parasitóide e nem pela fase embrionária do hospedeiro. A razão sexual foi semelhante nas três fases embrionárias do hospedeiro para fêmeas de T. exiguum com 24, 48 e 72 horas de idade. Ao avaliar os descendentes do parasitóide provenientes de ovos com três, dois e um dia de desenvolvimento embrionário, verificou-se que os maiores valores de longevidade foram obtidos quando foram usadas fêmeas recém-emergidas ou com 48 e 72 horas de vida, respectivamente. Estes resultados indicam a importância da idade do parasitóide, bem como o perído de desenvolvimento embrionário do hospedeiro para manter a qualidade de T. exiguum em laboratório, em uma criação massal, e também nas liberações de campo para o controle biológico de pragas.The objective of this work was to evaluate the influence of the embryonic development of eggs from the P. xylostella host on Trichogramma exiguum females of different ages. Fifty females – either just-emerged or 24, 48, 72 and 96 hours after emergence of this parasitoid were divided into five groups. Each female was offered a recipient with 30 P. xylostella eggs, which were 1-, 2- and 3-days-old. The greatest rates of parasitism were observed on eggs with 3 days of embryonic development, with exception of those 72-hours

Materiales de vaciado aglutinados con carbonato cálcico de origen biológico

OpenAIRE

Abelló Ulloa, Sol

2002-01-01

La tesis que se presenta tiene por objeto la obtención de copias que reproduzcan fielmente, obras originales compuestas de carbonato cálcico (ya sea piedra, piezas arqueológicas, pintura mural, etc., así como piezas resultantes de la actividad de distintos organismos vivos, como conchas, marfiles, huesos, etc.), mediante el vaciado de materiales aglutinados con carbonado cálcico de origen biológico. En un principio, este proyecto de investigación se basaba únicamente en la obtención de copias...

Organizational influence on the occurrence of work accidents involving exposure to biological material La influencia de la organización en la ocurrencia de accidentes de trabajo con exposición a material biológico Influência organizacional na ocorrência de acidentes de trabalho com exposição a material biológico

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Maria Helena Palucci Marziale

2013-02-01

instituição de 122 trabalhadores de enfermagem, alocados nos grupo-controle (trabalhadores não acidentados e no grupo-caso (trabalhadores acidentados, ambos compostos por 13 enfermeiros e 48 auxiliares e/ou técnicos de enfermagem. RESULTADOS: 386 acidentes foram registrados, as lesões percutâneas ocorreram em 79% dos casos, as agulhas foram os materiais envolvidos em 69,7% dos acidentes e em 81,9% dos acidentes houve contato com sangue. Quanto à influência da cultura organizacional sobre a ocorrência de acidentes, os resultados obtidos na análise dos dois grupos não demonstraram diferenças significativas entre os escores médios, atribuídos pelos trabalhadores, para cada categoria de valor ou prática organizacional. CONCLUSÃO: conclui-se que os acidentes com exposição a material biológico precisam ser evitados, no entanto, não foi possível constatar a influência dos valores e práticas.

Avaliação do efeito de borda da Reserva Biológica de Pindorama, SP

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M. T. V. N. Abdo

2015-10-01

Full Text Available Caracterizou dois fragmentos de floresta estacional semidecidual da Reserva Biológica de Pindorama, SP. Em 65 parcelas de 400 m2 avaliou-se: grau de infestação na parcela, distância da borda, altura, área basal e grau de infestação das quatro maiores árvores e num quadrante sorteado avaliou-se solo, a altitude, o número de espécies, o número, a área basal e a altura de todos indivíduos arbóreos com diâmetro a altura do peito (DAP ≥ a 5 cm e a fitossociologia. O agrupamento hierárquico dividiu as parcelas em dois grupos onde determinou-se valores médios das variáveis, Índices de diversidade de espécies (H’ e Coeficiente de equabilidade (J e a similaridade entre os grupos com o Índice de similaridade de Jaccard (ISJ. O agrupamento hierárquico, k-médias e componentes principais caracterizaram grupos de parcelas semelhantes e as variáveis com maior poder de discriminação foram: altura das quatro maiores árvores, número de indivíduos por parcelas, área basal total, infestação por parcelas, número de espécies. No Grupo 2 houve maior infestação de plantas invasoras e lianas nas quatro maiores árvores e menor distância das parcelas da borda com mais parcelas sob efeito de borda (31,75%. O Grupo 1  teve menor porcentagem  de parcelas sob efeito de borda (22,22%. Edge effect evaluation of Pindorama Biological Reserve-SPAbstract: Edge effect evaluation in two forest remnants in the Biological Reserve Pindorama, SP, in 65 plots of 400 m2, using data of: degree of infestation in the plot, distance from edge, height, basal area and degree of infestation of the four largest trees. In a random quadrant were evaluated soil and altitude, species number, number, basal area and height of trees with diameter at breast height (DBH ≥ 5 cm and phytosociological describers: density absolute and relative, relative dominancy, frequency relative and absolute , importance value, species diversity index (H ', evenness

Workshop on polarized neutron filters and polarized pulsed neutron experiments

International Nuclear Information System (INIS)

Itoh, Shinichi

2004-07-01

The workshop was held in KEK by thirty-three participants on April 26, 2004. The polarized neutron filter method was only discussed. It consists of three parts; the first part was discussed on the polarized neutron methods, the second part on the polarized neutron experiments and the third on the pulse neutron spectrometer and polarized neutron experiments. The six papers were presented such as the polarized 3 He neutron spin filter, neutron polarization by proton polarized filter, soft master and neutron scattering, polarized neutron in solid physics, polarization experiments by chopper spectroscope and neutron polarization system in superHRPD. (S.Y.)

New Data Services for Polar Investigators from Integrated Earth Data Applications (IEDA)

Science.gov (United States)

Nitsche, F. O.; Ferrini, V.; Morton, J. J.; Arko, R. A.; McLain, K.; O'hara, S. H.; Carbotte, S. M.; Lehnert, K. A.; IEDA Team, I.

2013-12-01

Accessibility and preservation of data is needed to support multi-disciplinary research in the key environmentally sensitive Polar Regions. IEDA (Integrated Earth Data Applications) is a community-based data facility funded by the US National Science Foundation (NSF) to support, sustain, and advance the geosciences by providing data services for observational solid earth data from the Ocean, Earth, and Polar Sciences. IEDA tools and services relevant to the Polar Research Community include the Antarctic and Southern Ocean Data System (ASODS), the U.S. Antarctic Program Data Coordination Center (USAP-DCC), GeoMapApp, as well as a number of services for sample-based data (SESAR and EarthChem). In addition to existing tools, which assist Polar investigators in archiving their data, and creating DIF records for global searches in AMD, IEDA recently added several new tools and services that will provide further support for investigators with the data life cycle process. These include a data management plan (http://www.iedadata.org/compliance/plan) and data compliance reporting tool (http://www.iedadata.org/compliance/report) that will help investigators comply with the requirements of funding agencies such as the National Science Foundation (NSF). Data, especially from challenging Polar Regions, are likely to be used by other scientists for future studies. Therefore, data acknowledgment is an important concern of many investigators. To encourage data acknowledgments by data users, we link references of publications (when known) to datasets and cruises registered within the ASODS system as part of our data curation services (http://www.marine-geo.org/portals/antarctic/references.php). In addition, IEDA offers a data publication service to register scientific data with DOI's, making data sets citable as publications with attribution to investigators as authors. IEDA is a publication agent of the DataCite consortium. Offering such services provides additional incentives

Terapia com agentes biológicos na criança e no adolescente Treatment with biologic agents in child and adolescent

Directory of Open Access Journals (Sweden)

Ricardo Maisse Suehiro

2010-06-01

Full Text Available OBJETIVO: Revisar os mecanismos fisiopatológicos e novos alvos terapêuticos, os agentes biológicos disponíveis, principais indicações e a evidência científica atual para o uso de terapias biológicas na população pediátrica. FONTES DE DADOS: Pesquisa na base de dados Medline e SciELO, nas línguas inglesa e portuguesa, entre 2000 e 2009. As palavras-chave usadas foram "agentes biológicos", "crianças" e "adolescentes". SÍNTESE DOS DADOS: Os agentes biológicos são uma importante opção terapêutica para tratar as doenças autoimunes refratárias às terapias convencionais na infância e na adolescência. Com exceção da artrite idiopática juvenil, a maioria dos estudos em outras doenças autoimunes não é controlada. CONCLUSÕES: Os agentes biológicos têm demonstrado eficácia no tratamento de doenças autoimunes pediátricas como artrite idiopática juvenil, miopatias idiopáticas inflamatórias, lúpus eritematoso juvenil, vasculites, uveítes crônicas, doenças inflamatórias intestinais e púrpura trombocitopênica imune crônica, assim como no linfoma não-Hodgkin. Considerando-se o custo elevado e os potenciais eventos adversos, o uso desses agentes deve ser individualizado e acompanhado por especialista.OBJECTIVE: To review the physiopathology and new therapeutical targets, the available biologic agents, the main indications and the current scientific evidence for the use of biological therapies in the pediatric population. DATA SOURCES: A bibliographical search was obtained from Medline and SciELO databases in English and Portuguese from 2000 to 2009. The key-words included were "biologic agent", "children" and "adolescent". DATA SYNTHESIS: Biologic agents are important therapeutic options to treat refractory autoimmune diseases to conventional therapies in childhood and adolescence. Excluding juvenile idiopathic arthritis, the majority of studies in other autoimmune diseases are uncontrolled trials. CONCLUSIONS

Neutron polarization in polarized 3He targets

International Nuclear Information System (INIS)

Friar, J.L.; Gibson, B.F.; Payne, G.L.; Bernstein, A.M.; Chupp, T.E.

1990-01-01

Simple formulas for the neutron and proton polarizations in polarized 3 He targets are derived assuming (1) quasielastic final states; (2) no final-state interactions; (3) no meson-exchange currents; (4) large momentum transfers; (5) factorizability of 3 He SU(4) response-function components. Numerical results from a wide variety of bound-state solutions of the Faddeev equations are presented. It is found that this simple model predicts the polarization of neutrons in a fully polarized 3 He target to be 87%, while protons should have a slight residual polarization of -2.7%. Numerical studies show that this model works very well for quasielastic electron scattering

When measured spin polarization is not spin polarization

International Nuclear Information System (INIS)

Dowben, P A; Wu Ning; Binek, Christian

2011-01-01

Spin polarization is an unusually ambiguous scientific idiom and, as such, is rarely well defined. A given experimental methodology may allow one to quantify a spin polarization but only in its particular context. As one might expect, these ambiguities sometimes give rise to inappropriate interpretations when comparing the spin polarizations determined through different methods. The spin polarization of CrO 2 and Cr 2 O 3 illustrate some of the complications which hinders comparisons of spin polarization values. (viewpoint)

Histologia do fígado de tilápia do Nilo ( Oreochromis niloticus alimentados com dietas contendo silagem biológica de pescado

Directory of Open Access Journals (Sweden)

Claucia A. Honorato

2014-12-01

Full Text Available Resumo: Este estudo teve como objetivo avaliar as possíveis alterações histopatológicas hepática de tilápias do Nilo alimentadas com dietas contendo silagem biológica de pescado com diferentes concentrações protéicas. Foram utilizados 180 juvenis alimentados com dietas contendo três níveis de proteína (20, 24 and 28% PB, e duas proporções de silagem biológica (¼ e ½ durante 75 dias. Os fragementos de fígado foram fixados em Bouin e inclusos em Histosec®. Posteriorente foram cortados em microtomo com espessura de 2 a 5μm. O método utilizado para coloração foi hematoxilina/eosina e PAS. Os cortes histológicos foram analisados em microscopio de luz. O desarranjo na morfologia do fígado dos peixes alimentados com silagem biológica foi influenciado pelos altos níveis protéicos, e pelo aumento ½ de proporções de proteínas de origem animal das dietas. Foi observado que a variação dos hepatócitos está diretamente ligada com o tipo da dieta fornecida para os peixes. Nos peixes alimentados com as dietas contendo 28% PB, o fígado apresentou desarranjo da estrutura cordonal dos hepatócitos, pontos de necrose e deslocamento do núcleo para periferia. Níveis elevados de silagem biológica de pescado provoca alterações deletérias no fígado. O nível de proteína adequado para manter o desenvolvimento associado à saúde do peixe é de 24%PB.

Gimnospermas, parásitas, rastreras y saprófitas de la Reserva Biológica Indio-Maíz, Río San Juan, Nicaragua.

Directory of Open Access Journals (Sweden)

Franklin Flores

2000-02-01

Full Text Available Se presenta un estudio sobre plantas gimnospermas, rastreras, parásitas y saprofitas de la reserva biológica Indio-Maiz de RIO San Juan, Nicaragua. Se reportan 14 familias de estos grupos, dentrode las cuales hay 22 géneros y 27 especies. Estas familias se distribuyeron en ocho rastreras, tres parásitas, dos gimnospermas y una saprófita. Consideramos que este trabajo contribuirá al conocimiento de la diversidad biológica del país y servirá al desarrollo del país, así como del área de estudio y la región estudiada.

Aspectos biológicos y control de un gracilláriido (Gracillariidae: Lepidóptera) en Caesalpinia spinosa (Mol.) Kuntze (1898), en Cajamarca, Perú

OpenAIRE

Murga Orrillo, Hipólito; Abanto Rodriguez, Carlos; Polo Vargas, Ana Rosa

2016-01-01

Se tuvo por objetivo determinar aspectos biológicos, identificar enemigos naturales, y establecer periodos oportunos de control de un gracillariido plaga de tara. Los aspectos biológicos y los enemigos naturales se evaluaron en campo y en laboratorio, los periodos oportunos de control se determinó por interacción hospedero-plaga. Los resultados, el huevo dura 7,8 días y mide 0,34x0,21mm; la larva presenta 4 instares y dura 35,7 días, variando de medidas entre 1o y 4o instar de 0,09 a 0,65 mm ...

Oncogene-inducible organoids as a miniature platform to assess cancer characteristics

NARCIS (Netherlands)

Mizutani, Tomohiro; Tsukamoto, Yoshiyuki; Clevers, Hans

2017-01-01

Direct effects of oncogenic proteins or inhibitor treatments on signaling pathways are difficult to assess in transgenic mice. In this issue, Riemer et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201610058) demonstrate that oncogene-inducible organoids offer the experimental versatility of

Research on generating various polarization-modes in polarized illumination system

Science.gov (United States)

Huang, Jinping; Lin, Wumei; Fan, Zhenjie

2013-08-01

With the increase of the numerical aperture (NA), the polarization of light affects the imaging quality of projection lens more significantly. On the contrary, according to the mask pattern, the resolution of projection lens can be improved by using the polarized illumination. That is to say, using the corresponding polarized beam (or polarization-mode) along with the off-axis illumination will improve the resolution and the imaging quality of the of projection lens. Therefore, the research on the generation of various polarization modes and its conversion methods become more and more important. In order to realize various polarization modes in polarized illumination system, after read a lot of references, we provide a way that fitting for the illumination system with the wavelength of 193nm.Six polarization-modes and a depolarized mode are probably considered. Wave-plate stack is used to generate linearly polarization-mode, which have a higher degree polarization. In order to generate X-Y and Y-X polarization mode, the equipment consisting of four sectors of λ/2 wave plate was used. We combined 16 sectors of λ/2 wave plate which have different orientations of the "slow" axis to generate radial and azimuthal polarization. Finally, a multi-polarization control device was designed. Using the kind of multi-polarization control device which applying this method could help to choose the polarization modes conveniently and flexibility for the illumination system.

Polarization properties of linearly polarized parabolic scaling Bessel beams

Energy Technology Data Exchange (ETDEWEB)

Guo, Mengwen; Zhao, Daomu, E-mail: zhaodaomu@yahoo.com

2016-10-07

The intensity profiles for the dominant polarization, cross polarization, and longitudinal components of modified parabolic scaling Bessel beams with linear polarization are investigated theoretically. The transverse intensity distributions of the three electric components are intimately connected to the topological charge. In particular, the intensity patterns of the cross polarization and longitudinal components near the apodization plane reflect the sign of the topological charge. - Highlights: • We investigated the polarization properties of modified parabolic scaling Bessel beams with linear polarization. • We studied the evolution of transverse intensity profiles for the three components of these beams. • The intensity patterns of the cross polarization and longitudinal components can reflect the sign of the topological charge.

Comportamento parental de Brachyteles hypoxanthus (Kuhl 1820) (Primates - Atelidae) na estação biológica de Caratinga - MG /

OpenAIRE

Souza, Karynna Tolentino de

2007-01-01

Orientador : Fernando C. Passos Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Zoologia. Defesa: Curitiba, 2007 Inclui bibliografia e anexos Area de concentração: Zoologia

Accidentes ocupacionales de riesgo biológico en Antioquia, Colombia. Enero de 2010 a diciembre de 2011

Directory of Open Access Journals (Sweden)

Franco E Montufar Andrade

Full Text Available Antecedentes: Los accidentes ocupacionales de riesgo biológico tienen como mayor riesgo postexposición la seroconversión para el virus de la inmunodeficiencia humana (VIH y virus de la hepatitis C (VHC y B (VHB. En la literatura latinoamericana aún faltan estudios que aporten información al respecto. Objetivo: Describir las características epidemiológicas de los accidentes ocupacionales de riesgo biológico. Metodología: Estudio descriptivo longitudinal. Resultados: Se describen 231 episodios de riesgo biológico. La mediana de edad fue 30 años. Un 65,8% fueron mujeres. Las principales actividades laborales fueron: auxiliares de enfermería (22,9%, aseo hospitalario (16,5%, estudiantes (14,3%, recolección de basuras (5,2% y médicos (4,8%. El mecanismo del accidente fue: punción (77%, herida cortante (11,3% y contacto con mucosas (9,1%. En 24% la fuente fue conocida y de estas fueron positivas para VIH un 62,5%, para VHB un 3,5% y para VHC un 5,3%. Recibieron profilaxis postexposición (PPE un 75,8% de los 231. Entre los expuestos a fuente VIH positiva, recibieron PPE biconjugada 85,1% y terapia triple 14,8% De los que recibieron profilaxis, 40% presentaron reacciones adversas, siendo las gastrointestinales (77,1% y las neurológicas (45,7% las más frecuentes. Al ingreso, un 67,1% tenían anticuerpos protectores para VHB. Durante el seguimiento se confirmó una seroconversión postexposición para VIH. Conclusión: El riesgo de adquirir infecciones postexposición ocupacional es una realidad en nuestro medio; se debe hacer énfasis en estrategias de prevención de exposición, introyectar la cultura del reporte y el manejo adecuado de la profilaxis postexposición.

Polarized nuclear target based on parahydrogen induced polarization

OpenAIRE

Budker, D.; Ledbetter, M. P.; Appelt, S.; Bouchard, L. S.; Wojtsekhowski, B.

2012-01-01

We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ($\\sim$100 Hz) polarization reversal, and operation with large intensity of an electron beam.

Constitutive equations for the Doi-Edwards model without independent alignment

DEFF Research Database (Denmark)

Hassager, Ole; Hansen, Rasmus

2010-01-01

We present two representations of the Doi-Edwards model without Independent Alignment explicitly expressed in terms of the Finger strain tensor, its inverse and its invariants. The two representations provide explicit expressions for the stress prior to and after Rouse relaxation of chain stretch......, respectively. The maximum deviations from the exact representations in simple shear, biaxial extension and uniaxial extension are of order 2%. Based on these two representations, we propose a framework for Doi-Edwards models including chain stretch in the memory integral form....

Características biológicas de parasitóide de ovos criados em diferentes hospedeiros

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Ariana Lisboa Meira

2017-04-01

Full Text Available As espécies de Trichogramma são agentes biológicos que contribuem para o controle de lepidópteros. Objetivou-se neste trabalho identificar qual espécie de Trichogramma apresenta melhor desempenho biológico quando criados em ovos de Anagasta kuehniella (Lepidoptera: Pyralidae, Helicoverpa zea (Boddie (Lepidoptera: Noctuidae e Plutella xylostella Linnaeus (Lepidoptera: Plutellidae. Desta forma os parâmetros biológicos avaliados no período de ovo a adulto foram duração de ovo a adulto e percentual de emergência e no estágio adulto avaliou-se número de ovos parasitados, número de indivíduos por ovo e razão sexual em Trichogramma atopovirilia Oatman & Planter (Hymenoptera: Trichogrammatidae e Trichogramma exiguum Pinto & Planter (Hymenoptera: Trichogrammatidae.  Para o período de ovo a adulto, A. kuehniella, H. zea e P. xylostella não apresentaram diferença quando criados com as mesmas espécies de Trichogramma para a duração do ciclo de desenvolvimento e não houve diferença para o percentual de emergência entre os três hospedeiros em estudo. Em relação aos parâmetros avaliados no estágio adulto, para número de ovos parasitados, somente A. kuehniella, diferenciou entre as espécies de Trichogramma. O número de indivíduos por ovo, os maiores valores foram observados quando as espécies de Trichogramma foram criadas com ovos de H. zea. A razão sexual, T. atopovirilia diferiu apenas para A. kuehniella. As duas espécies de Trichogramma estão aptas a se desenvolverem nos hospedeiros A. kuehniella e P. xylostella. Contudo para o hospedeiro H. zea, T. exiguum foi à espécie que obteve melhor desempenho, parasitando maior número de ovos e obtendo maior número de indivíduos por ovo.

The arabidopsis thaliana AGRAVITROPIC 1 gene encodes a component of the polar-auxin-transport efflux carrier

Science.gov (United States)

Chen, R.; Hilson, P.; Sedbrook, J.; Rosen, E.; Caspar, T.; Masson, P. H.

1998-01-01

Auxins are plant hormones that mediate many aspects of plant growth and development. In higher plants, auxins are polarly transported from sites of synthesis in the shoot apex to their sites of action in the basal regions of shoots and in roots. Polar auxin transport is an important aspect of auxin functions and is mediated by cellular influx and efflux carriers. Little is known about the molecular identity of its regulatory component, the efflux carrier [Estelle, M. (1996) Current Biol. 6, 1589-1591]. Here we show that mutations in the Arabidopsis thaliana AGRAVITROPIC 1 (AGR1) gene involved in root gravitropism confer increased root-growth sensitivity to auxin and decreased sensitivity to ethylene and an auxin transport inhibitor, and cause retention of exogenously added auxin in root tip cells. We used positional cloning to show that AGR1 encodes a putative transmembrane protein whose amino acid sequence shares homologies with bacterial transporters. When expressed in Saccharomyces cerevisiae, AGR1 promotes an increased efflux of radiolabeled IAA from the cells and confers increased resistance to fluoro-IAA, a toxic IAA-derived compound. AGR1 transcripts were localized to the root distal elongation zone, a region undergoing a curvature response upon gravistimulation. We have identified several AGR1-related genes in Arabidopsis, suggesting a global role of this gene family in the control of auxin-regulated growth and developmental processes.

Síndrome de Cotard: Dois Casos de Recusa Alimentar

OpenAIRE

Teixeira, Bruno Gonçalves; Araújo, Ana Filipa; Perestrelo, João Ferreira

2015-01-01

Introdução: A Síndrome de Cotard é uma condição clínica relativamente rara que se caracteriza por vários graus de delírios niilistas, quase sempre na forma de auto-negação. Objectivos: Descrever dois casos de Síndrome de Cotard associados a recusa alimentar e realizar uma revisão do conceito e das características clínicas desta síndrome. Métodos: Realizou-se a recolha de informa- ção de dois casos clínicos associados a recusa alimentar. Procedeu-se a uma revisão ...

Fusion of a polarized projectile with a polarized target

International Nuclear Information System (INIS)

Christley, J.A.; Johnson, R.C.; Thompson, I.J.

1995-01-01

The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned 165 Ho target with 16 O and polarized 7 Li beams are presented

INFLUENCIA DE LA FERMENTACIÓN LÁCTICA (ABONO BOKASHI) EN EL PRE-COMPOST PARA LA PRODUCCIÓN DE BIOGÁS Y BIOL EN BIODIGESTORES TIPO BATCH

OpenAIRE

Torres T., Allen; Igeniero Ambiental Egresado de la UNALM, Lima (Perú).; Quipuzco U., Lawrence; Universidad Nacional Agraria La Molina (Perú).; Meza C., Víctor; Universidad Nacional Agraria La Molina (Perú).

2015-01-01

El trabajo de investigación titulado: “Influencia de la fermentación láctica (abono bokashi) en el pre-compost para la producción de biogás y biol en biodigestores tipo batch” surge como una alternativa de tratamiento previo a los sustratos antes de colocarlos en los biodigestores y de esta manera mejorar la calidad de los subproductos generados: biogás y biol. La investigación se inició en Agosto del 2012, empleándose reactores que simulan a un biodigestor del tipo batch para tres tratamient...

A dual layer DOI GSO block detector for a small animal PET

International Nuclear Information System (INIS)

Yamamoto, Seiichi

2009-01-01

For a high resolution animal positron emission tomography (PET), depth-of-interaction (DOI) is a useful method to improve both spatial resolution and sensitivity. Gd 2 SiO 5 (GSO) with different amounts of Ce can provide different decay times and is ideal for DOI detector using pulse shape analysis. Dual layer DOI GSO block detectors using different amounts of Ce were developed for a new animal PET. The DOI GSO block detector employed two types of GSOs; one with 1.5 mol% Ce concentration (decay time: 35 ns) and the other with 0.5 mol% (decay time: 60 ns). These two GSO types were optically coupled in the DOI direction. The sizes of single GSOs were 1.9 mmx1.9 mmx6 mm and 1.9 mmx1.9 mmx9 mm, for 1.5 and 0.5 mol%, respectively. These GSO were arranged by 11x37 matrix and optically coupled to three position sensitive photomultiplier tubes (PSPMTs), where the PSPMTs used were Hamamatsu R8520U-00-C12. Different lengths of reflectors were used between crystals to increase the useful field-of-view (FOV) of the PSPMT and to avoid the dead areas between PSPMTs. With this configuration, almost all islands in a 2-D position histogram corresponding to GSO cells could be separated. The width of the GSO block was 22 mm in the transaxial direction and 74 mm in axial direction with no gaps. Also, two types of GSO of different decay time could be separated using dual integration method for pulse shape analysis. These results indicate that developed block detectors might be useful for a high resolution and high sensitivity animal PET with dual layer DOI detection capability, with no gaps in transaxial or axial directions.

Evaluación de riesgo biológico en el Hospital Rey Don Jaime

Directory of Open Access Journals (Sweden)

Salomé Benavent Nácher

2007-03-01

Full Text Available Objetivo: El propósito del presente trabajo es realizar una evaluación del riesgo biológico existente para los trabajadores del Hospital con el fin de identificar los puestos de trabajo y microorganismos que suponen mayor riesgo y poder adoptar medidas preventivas. Métodos: Se aplicó la metodología BIOGAVAL de evaluación de riesgo biológico desarrollado por el Gabinete de Seguridad e Higiene de Valencia. Dicho método contempla una identificación de los microorganismos presentes mas probables, su posible daño a la salud, mecanismos de transmisión, porcentaje de población diana vacunado y el efecto protector de las medidas higiénicas. Se aplicó a los distintos puestos de trabajo que presentan riesgo biológico exceptuando cocina. Resultados: Los resultados evidencian un mayor riesgo para los microorganismos de transmisión aérea y con baja protección vacunal, así como un nivel de riesgo superior (comparado con otros trabajadores de los ATS/DUE de urgencias. Conclusiones: El método se ha revelado útil para evidenciar los puestos de trabajo más peligrosos así como los agentes microbiológicos de mayor riesgo. Igualmente aporta una orientación sobre la prioridad para la aplicación de medidas preventivas de control.Objective: The purpose of this work is to realize an evaluation of the existing biological risk for the staff at the hospital with the aim of both identifying the jobs and microorganisms which mean a higher risk and to be able to adopt preventive measures. Methods: It was applied the BIOGAVAL methodology of evaluation of biological risk developed by the Safety and Hygiene Office in Valencia. This method deals with an identification of the most probable present microorganisms, their possible hurt for health, transmission mechanisms, percentage of target population vaccinated and the protective effect of the hygienic measures. It was applied to the different jobs which show biological risk except for the kitchen ones

77 FR 17493 - Agency Information Collection Activities: Proposed Collection; Comment Request; DOI Generic...

Science.gov (United States)

2012-03-26

... justify the proposed sample size, the expected response rate, methods for assessing potential non...: Proposed Collection; Comment Request; DOI Generic Clearance for the Collection of Qualitative Feedback on... (Generic ICR): ``DOI Generic Clearance for the Collection of Qualitative Feedback on Agency Service...

Riesgos biológico y químico en planta de compostaje de ingenio azucarero, Valle del Cauca, Colombia

Directory of Open Access Journals (Sweden)

Ivá Darío López Villalobos

2016-12-01

Full Text Available El riesgo químico y biológico, son los principales riesgos a los que se exponen los colaboradores de la planta de compostaje del ingenio azucarero, es sin duda una posible causa de enfermedades de tipo respiratorio y de la piel, así como de enfermedades infecciosas, lo cual afecta directamente la productividad de la empresa. Se utilizó un estudio descriptivo cuya metodología se realizó en tres fases, una primera de diagnóstico e identificación de peligros, en seguida según los resultados de las listas de chequeo, se realizó una matriz DOFA, luego los árboles de problemas se convirtieron en arboles de objetivos remplazando cada uno de los problemas y consecuencias por las soluciones, así se definieron los objetivos prioritarios a emprender, para alcanzar las acciones de mejora en el proceso del compostaje. De los resultados obtenidos se resalta que el riesgo biológico tiene una interpretación de riesgo III (alto, mejorable y representa el 55,6%, mientras que el riesgo químico con una interpretación de riesgo I (muy alto, crítico representa el 44,4%. También debe mencionarse que la planta de compostaje presenta un déficit en las medidas de prevención y protección por el incumplimiento de la normatividad legal vigente en seguridad y salud. Es importante que la planta de compostaje empiece a gestionar el cumplimiento de lo establecido en el programa de intervención propuesto para la misma, para de esta forma disminuir la vulnerabilidad del personal expuesto a riesgos biológico y químico.

Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2)

Science.gov (United States)

Wohltmann, Ingo; Lehmann, Ralph; Rex, Markus

2017-07-01

The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs) and Earth system models (ESMs) to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx), HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect caused by the

Human platelet ( sup 125 I)R-DOI binding sites. Characterization by in vitro autoradiography

Energy Technology Data Exchange (ETDEWEB)

Himeno, A.; Saavedra, J.M. (National Institute of Mental Health, Bethesda, MD (USA))

1990-02-01

We quantified binding sites for 2,5-dimethoxy-4-iodo-phenylisopropylamine (DOI), a 5-HT2 agonist and hallucinogen, in human platelets. We incubated sections from human platelet pellets with ({sup 125}I)R-DOI with or without 1 mumol/L ketanserin, followed by autoradiography and computerized microdensitometry. We corrected the values of binding density by the protein content of each section with a densitometric protein assay. The present method revealed a single class of high affinity binding sites for ({sup 125}I)R-DOI, with a Kd of 6.4 +/- 0.7 nmol/L and a Bmax of 100 +/- 10 fmol/mg protein. Kd and Bmax for ({sup 125}I)R-DOI determined by the classical membrane binding assay, were 2.7 +/- 0.4 nmol/L and 100 +/- 10 fmol/mg protein, respectively. The present method is precise, very sensitive, and allows the characterization of ({sup 125}I)R-DOI binding in sections obtained from as little as 3 ml of blood. Standardization is possible after correction by the protein content of each individual section.

Optimization, evaluation and calibration of a cross-strip DOI detector

Science.gov (United States)

Schmidt, F. P.; Kolb, A.; Pichler, B. J.

2018-02-01

This study depicts the evaluation of a SiPM detector with depth of interaction (DOI) capability via a dual-sided readout that is suitable for high-resolution positron emission tomography and magnetic resonance (PET/MR) imaging. Two different 12  ×  12 pixelated LSO scintillator arrays with a crystal pitch of 1.60 mm are examined. One array is 20 mm-long with a crystal separation by the specular reflector Vikuiti enhanced specular reflector (ESR), and the other one is 18 mm-long and separated by the diffuse reflector Lumirror E60 (E60). An improvement in energy resolution from 22.6% to 15.5% for the scintillator array with the E60 reflector is achieved by taking a nonlinear light collection correction into account. The results are FWHM energy resolutions of 14.0% and 15.5%, average FWHM DOI resolutions of 2.96 mm and 1.83 mm, and FWHM coincidence resolving times of 1.09 ns and 1.48 ns for the scintillator array with the ESR and that with the E60 reflector, respectively. The measured DOI signal ratios need to be assigned to an interaction depth inside the scintillator crystal. A linear and a nonlinear method, using the intrinsic scintillator radiation from lutetium, are implemented for an easy to apply calibration and are compared to the conventional method, which exploits a setup with an externally collimated radiation beam. The deviation between the DOI functions of the linear or nonlinear method and the conventional method is determined. The resulting average of differences in DOI positions is 0.67 mm and 0.45 mm for the nonlinear calibration method for the scintillator array with the ESR and with the E60 reflector, respectively; Whereas the linear calibration method results in 0.51 mm and 0.32 mm for the scintillator array with the ESR and the E60 reflector, respectively; and is, due to its simplicity, also applicable in assembled detector systems.

Salud del suelo: en la búsqueda de un indicador biológico de sustentabilidad

OpenAIRE

Ortíz, Jimena; Faggioli, Valeria; Ullé, Jorge A.

2015-01-01

Los indicadores de calidad de suelo han sido motivo de numerosas investigaciones en los últimos años. Sin embargo, la complejidad en la interpretación de los resultados de laboratorio dificulta su implementación tanto para los productores como para el asesor. Es por ello que el objetivo de este trabajo fue evaluar el comportamiento de indicadores biológicos de suelo sobre diferentes intensidades de manejo orgánico, con énfasis en el coeficiente metabólico. Se analizó un set de datos provenien...

Antártica: fuente de recursos biológicos para la biotecnología nacional

OpenAIRE

Blamey, J.

2008-01-01

En diciembre del 2007, Innova-Chile de CORFO aprobó el financiamiento del proyecto “Antártica: Fuente de recursos biológicos para la biotecnología nacional”. Este proyecto tiene como fin crear una plataforma que facilite el acceso a los recursos antárticos de microorganismos y plantas, de una forma que permitirá su valorización para la biotecnología chilena y su desarrollo científico en el área. Por sus únicas condiciones de aislamiento y bajas temperaturas, la Antártica alberga un potencial ...

The digital object identifier (DOI in electronic scientific journals of communication and information

Directory of Open Access Journals (Sweden)

Erik André de Nazaré Pires

2017-06-01

Full Text Available The present study seeks to investigate the use of the Digital Object Identifier (DOI in the scientific journals of Communication and Information and, providing new integration utilities with the Lattes Platform. In this sense, it aims to inform the existing titles in Communication Information in electronic format, demonstrate the importance of DOI in the integration with the Lattes Platform in order to guarantee author credibility and analyze the characteristics of publications that have DOI. The methodology used for the development of this study is bibliographic, research with descriptive-descriptive characteristics. From the development of the research, it is inferred that of all the analyzed journals (33 journals, 10 titles in the evaluation of 2013 and 06 titles of the evaluation of 2014 present DOI in their publications, all have WebQualis classification, Qualis A1 in the area Communication and Information. Most publications are international and only 3 titles are national. It is necessary that journals, principally national ones, accompany new technologies such as DOI for objects and ORCID for the identification of people, bringing more mechanisms that guarantee authors 'credibility and to bring the researchers' connection, and both can already be adopted in the Platform Lattes.

Acerca de la judicialización de la ciudadanía biológica: biomedicina y políticas de la vida

Directory of Open Access Journals (Sweden)

Marisa Germain

2014-09-01

Full Text Available El proceso de judicialización de la biopolítica encuentra en la Argentina contemporánea una forma singular. Las políticas de la vida, a partir del fin de la última dictadura militar (1976-1983 van a ser doblemente condicionadas por los efectos del terrorismo de Estado: por un lado, la búsqueda de la vida constituye el requisito político inicial para legitimar prácticamente todas las formas de interferencia en la vida colectiva; por otro lado, el nexo biológico entre las generaciones prueba ser el más potente soporte material y simbólico que sostiene la urgencia de nuevos movimientos sociales (MADRES, ABUELAS, FAMILIARES, HIJOS proporcionando un formato para desenganchar/reenganchar lo biológico en unas demandas políticas específicas. En este formato, nuevos desarrollos biomédicos se acoplan en direcciones estratégicas opuestas que posibilitan o limitan las atribuciones que el Estado tiene de asumir algún aspecto de la existencia biológica de sus ciudadanos. Para posibilitar este análisis, examinamos críticamente los aspectos de la perspectiva teórica engendrada por Michel Foucault, así como los desarrollos posteriores de Nikolas Rose, que contribuyen a la conceptualización necesaria para una analítica de las políticas de la vida efectivamente en curso.

Neutron polarization

International Nuclear Information System (INIS)

Firk, F.W.K.

1976-01-01

Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

Retraction: Pogačnik M, Žnidarčič D, Strgar J. A school garden in biotechnical education. Arch biol sci. 2014; 66(2:785-92, DOI: 10.2298/ABS1402785P

Directory of Open Access Journals (Sweden)

Editorial

2015-01-01

Full Text Available This is a notice of retraction of the article: A school garden in biotechnical education, published in the Archives of Biological Sciences in 2014, Vol. 66, Issue 2. Due to a printing error, caused by the journal, the same paper has already been published in the Archives of Biological Sciences, Vol. 66, Issue 1, 2014 (DOI: 10.2298/ABS1401393P. Therefore, the latter article is being retracted. The corresponding author has been informed of this error and retraction. We apologize to the authors and to the readers for this error. Link to the retracted article 10.2298/ABS1402785P

Three-photon polarization ququarts: polarization, entanglement and Schmidt decompositions

International Nuclear Information System (INIS)

Fedorov, M V; Miklin, N I

2015-01-01

We consider polarization states of three photons, propagating collinearly and having equal given frequencies but with arbitrary distributed horizontal or vertical polarizations of photons. A general form of such states is a superposition of four basic three-photon polarization modes, to be referred to as the three-photon polarization ququarts (TPPQ). All such states can be considered as consisting of one- and two-photon parts, which can be entangled with each other. The degrees of entanglement and polarization, as well as the Schmidt decomposition and Stokes vectors of TPPQ are found and discussed. (paper)

High production of fructooligosaccharides by levansucrase from ...

African Journals Online (AJOL)

SAM

2014-07-02

Jul 2, 2014 ... production activity of Zymomonas mobilis extracellular levansucrase. Process. Biochem. 38:701-706. http://dx.doi.org/10.1016/S0032-. 9592(02)00189-9. Belghith KM, Dahech I, Belghith H, Mejoud H (2012). Microbial production of levansucrase for synthesis of fructo-oligosaccharide. Int. J. Biol. Macromol.

The Cirque du Soleil of Golgi membrane dynamics.

Science.gov (United States)

Bankaitis, Vytas A

2009-07-27

The role of lipid metabolic enzymes in Golgi membrane remodeling is a subject of intense interest. Now, in this issue, Schmidt and Brown (2009. J. Cell Biol. doi:10.1083/jcb.200904147) report that lysophosphatidic acid-specific acyltransferase, LPAAT3, contributes to Golgi membrane dynamics by suppressing tubule formation.

The Cirque du Soleil of Golgi membrane dynamics

OpenAIRE

Bankaitis, Vytas A.

2009-01-01

The role of lipid metabolic enzymes in Golgi membrane remodeling is a subject of intense interest. Now, in this issue, Schmidt and Brown (2009. J. Cell Biol. doi:10.1083/jcb.200904147) report that lysophosphatidic acid?specific acyltransferase, LPAAT3, contributes to Golgi membrane dynamics by suppressing tubule formation.

Co-branding de marcas colectivas de carne de bovino: avaliação do valor atribuído pelos consumidores

OpenAIRE

Oliveira, Diana Judite Moura de

2014-01-01

Dissertação de Mestrado em Gestão Ocorrendo o Co-branding quando dois ou mais nomes de marcas já estabelecidas de diferentes instituições aparecem num mesmo produto, consideramos como pressuposto para a nossa investigação que uma forma de estimular a produção de carnes bovinas com Denominação de Origem Protegida (DOP) ou produzidas em modo de produção biológico seria pela associação em Co-branding destas duas marcas coletivas de carne bovina (DOP ou Biológica, individualmente ou em simultâ...

Polarization splitter and polarization rotator designs based on transformation optics.

Science.gov (United States)

Kwon, Do-Hoon; Werner, Douglas H

2008-11-10

The transformation optics technique is employed in this paper to design two optical devices - a two-dimensional polarization splitter and a three-dimensional polarization rotator for propagating beams. The polarization splitter translates the TM- and the TE-polarized components of an incident beam in opposite directions (i.e., shifted up or shifted down). The polarization rotator rotates the polarization state of an incoming beam by an arbitrary angle. Both optical devices are reflectionless at the entry and exit interfaces. Design details and full-wave simulation results are provided.

Diseño y construcción de un biodigestor anaeróbica vertical semicontinua para la obtención de gas metano y biol apartir de las cáscaras de naranja y mango.

OpenAIRE

Gonzabay Valdiviezo, Anthony William; Suárez Monroy, Pablo Moises

2016-01-01

En la elaboración del presente proyecto se pretende realizar el diseño y construcción de un biodigestor anaeróbico vertical semicontinuo para la obtención de gas metano y biol a partir de las cáscaras de naranja y mango. Esto se logrará al estimar los parámetros de diseño del Biodigestor anaeróbico, calculando la cantidad de gas metano y biol estimado que podría generar el biodigestor, además de construirlo y operarlo para la obtención de gas metano y biol. In the production of the presen...

Dinosaur demise in light of their alleged perennial polar residency

Science.gov (United States)

Lewy, Zeev

2017-10-01

The end-Cretaceous biological crisis is represented by the demise of the non-avian dinosaurs. However, most crucial biologically was the elimination of the photosynthesizing marine phyto- and zooplankton forming the base of the marine food chain. Their abrupt demise attests to sunlight screening darkening the atmosphere for a few years. Alvarez et al. (Science 208:1095-1108, 1980. doi: 10.1126/science.208.44) noticed in deep marine end-Cretaceous sediments an anomalous rise in the chemical element iridium (Ir), which is rare on planet Earth and thus suggests an extraterrestrial origin through an impact of a large asteroid. This impact would have ejected enormous quantities of particles and aerosols, shading the solar illumination as attested to by the elimination of the marine photosynthesizing plankton. Such a dark period must have affected life on land. The apparent cold-blooded non-avian dinosaurs, which were used to living in open terrains to absorb the solar illumination, became inactive during the dark period and were incapable of withstanding predators. This was in contrast to cold-blooded crocodilians, turtles and lizards that could hide in refuge sites on land and in the water. Dinosaur relics discovered in Cretaceous Polar Regions were attributed to perennial residents, surviving the nearly half-year-long dark winter despite their ability to leave. The polar concentrations of disarticulated dinosaur bones were suggested as having resulted from a catastrophic burial of a population by floods. However, this should have fossilized complete skeletons. Alternatively, herds of dinosaurs living in high latitudes might have been sexually driven to spend the half year of continuously illuminated polar summer for mating rather than for nourishment, in which the lower latitudes provided as well. The aggressive mating competitions would have left victims among the rivals and of young ones incidentally trampled over, all being consumed and their skeletons

Segurança do uso de terapias biológicas para o tratamento de artrite reumatoide e espondiloartrites

Directory of Open Access Journals (Sweden)

Licia Maria Henrique da Mota

2015-06-01

Full Text Available O tratamento das doenças reumáticas autoimunes sofreu uma progressiva melhora ao longo da última metade do século passado, que foi expandida com a contribuição das terapias biológicas ou imunobiológicos. No entanto, há que se atentar para as possibilidades de efeitos indesejáveis advindos da utilização dessa classe de medicações. A Sociedade Brasileira de Reumatologia (SBR elaborou um documento, baseado em ampla revisão da literatura, sobre os aspectos relativos à segurança dessa classe de fármacos, mais especificamente no que diz respeito ao tratamento da artrite reumatoide (AR e das espondiloartrites. Os temas selecionados pelos especialistas participantes, sobre os quais foram estabelecidas considerações quanto à segurança do uso de drogas biológicas, foram: ocorrência de infecções (bacterianas, virais, tuberculose, reações infusionais, reações hematológicas, neurológicas, gastrointestinais, cardiovasculares, ocorrências neoplásicas (neoplasias sólidas e da linhagem hematológica, imunogenicidade, outras ocorrências e reposta vacinal. Optou-se, por motivos didáticos, por se fazer um resumo da avaliação de segurança, de acordo com os tópicos anteriores, por classe de drogas/mecanismo de ação (antagonistas do fator de necrose tumoral, bloqueador da co-estimulação do linfócito T, depletor de linfócito B e bloqueador do receptor de interleucina-6. Em separado, foram tecidas considerações gerais sobre segurança do uso de biológicos na gravidez e na lactação. Esta revisão procura oferecer uma atualização ampla e equilibrada das experiências clínica e experimental acumuladas nas últimas duas décadas de uso de medicamentos imunobiológicos para o tratamento da AR e espondiloartrites.

De la riqueza biológica a la riqueza económica

Directory of Open Access Journals (Sweden)

Gustavo Correa Assmus

2011-01-01

Full Text Available Frente al deterioro ambiental por efectos de la producción y el consumo, la economía debe ofrecer respuestas fundamentadas en procesos de investigación, educación, responsabilidad y regulación, que permitan articular el aprovechamiento de los recursos naturales renovables, administrados y no administrados, con el fin de establecer un crecimiento económico-ambiental sostenible y racionalizado que cualifique la calidad de vida. Para esta propuesta se tomó información secundaria de origen empírico, la cual permitió elaborar una teorización analítica, que expresa de manera clara sus reflexiones y conjeturas, ofreciendo un camino por seguir en el proceso de transición de la riqueza biológica a la económica.

Polarization dynamics and polarization time of random three-dimensional electromagnetic fields

International Nuclear Information System (INIS)

Voipio, Timo; Setaelae, Tero; Shevchenko, Andriy; Friberg, Ari T.

2010-01-01

We investigate the polarization dynamics of random, stationary three-dimensional (3D) electromagnetic fields. For analyzing the time evolution of the instantaneous polarization state, two intensity-normalized polarization autocorrelation functions are introduced, one based on a geometric approach with the Poincare vectors and the other on energy considerations with the Jones vectors. Both approaches lead to the same conclusions on the rate and strength of the polarization dynamics and enable the definition of a polarization time over which the state of polarization remains essentially unchanged. For fields obeying Gaussian statistics, the two correlation functions are shown to be expressible in terms of quantities characterizing partial 3D polarization and electromagnetic coherence. The 3D degree of polarization is found to have the same meaning in the 3D polarization dynamics as the usual two-dimensional (2D) degree of polarization does with planar fields. The formalism is demonstrated with several examples, and it is expected to be useful in applications dealing with polarization fluctuations of 3D light.

Polarized electron sources

Energy Technology Data Exchange (ETDEWEB)

Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

1994-12-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

Polarized electron sources

International Nuclear Information System (INIS)

Prepost, R.

1994-01-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

Data DOIs - virtues and weak points from the perspective of the data journal ESSD

Science.gov (United States)

Pfeiffenberger, Hans; Carlson, David

2016-04-01

Fundamentally, data publication seeks to provide improved access, trust and utility for data users accompanied by improved recognition for data providers. The features of persistent identifier schemes used in this context and the policies of providers of their resolver systems can greatly contribute towards these aims! Unfortunately, we also recognize situations where identifier systems undermine some of our lofty data publication aims. From our 7 years of successful experience with the data journal ESSD, we will present our practical observations as well as future requirements on the DOI-system in particular, such as: * Most scientists contributing to or drawing benefit from ESSD seem to understand the notion of published data in the sense of a static, citable entity to build on, relying on its long term availability and integrity (as is the case with journal articles), secured by DOIs. * It is still true that many data providers - individuals or projects - can not find a repository for their (type of) data which would provide a DOI (or other persistent identifier) and that many data centers and databases holding valuable data have a hard time adding DOIs as a feature of their systems for conceptual, legacy or funding reasons. * The typical evolution of many important data collections or data products - such as the Global Carbon Budget - can adequately be tracked with yearly (or less frequent) issues of dataset and data article, each having a new DOI. However, issuing a new DOI for a dataset extended in time clashes with many producers' wish to amass all references to the developing dataset under one citation (and one DOI). * Current practises with DOIs and metadata associated with DOIs need to be clarified and amended so the identifier systems can and do express and track the relationships between versions of data, addressing extensions, corrections, modifications, revisions and retractions in an unambiguous (and machine readable) manner, while also removing

Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2

Directory of Open Access Journals (Sweden)

I. Wohltmann

2017-07-01

Full Text Available The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs and Earth system models (ESMs to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx, HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect

The Decision-Oriented Interview (DOI as a Marketing Instrument for Obtaining Information about Brands

Directory of Open Access Journals (Sweden)

Karl Westhoff

2014-11-01

Full Text Available The aim of our article is not to report an empirical study but to present a toolkit which can help to collect valid information about brands. The Decision-Oriented Interview, hereafter, DOI presents empirically proven behavior regularities in interviews as a collection of checklists. The DOI has shown its usefulness in different fields of interviewing e.g. as a selection interview, in forensic assessment or a method for oral examinations. The DOI collection of explicit rules for interview design, execution and summary is described as a toolkit for collecting information relevant in marketing. The purchase decisions are presented as a basis for describing brand-differentiating situations. The use of the rules collected in the DOI checklists has clear advantages over the conventional approach in which success depends on the experience of individual project managers.

Brasicáceas y perspectivas de control biológico del insecto plaga Plutella xylostella (Lepidóptera: Plutellidae utilizando Bacillus thuringiensis

Directory of Open Access Journals (Sweden)

Julieth Mena Guerrero

2017-09-01

Full Text Available La Plutella xylostella (L. es un insecto plaga que afecta principalmente los cultivos de brasicáceas o crucíferas como el repollo, coliflor, brócoli y rábano, entre otros. Las limitaciones del rendimiento y calidad de estos cultivos se deben principalmente al difícil manejo de esta plaga. En la actualidad, para controlar la P. xylostella se utilizan insecticidas de síntesis química, como piretroides, carbamatos u organofosforados, los cuales tienen acción inmediata pero causan efectos adversos en la salud y en el ambiente. Adicionalmente, la ausencia de enemigos naturales capaces de controlar a sus poblaciones, y su resistencia a numerosos insecticidas convencionales hacen que este insecto se establezca rápidamente en áreas productoras de brasicáceas. Se calcula que los costos mundiales asociados al control de la P. xylostella, sumados a las pérdidas en la producción agrícola, están entre cuatro y cinco billones de dólares anuales. Se han propuesto alternativas seguras, efectivas y de menor impacto ambiental, como el control biológico, que permite la producción sostenible de los cultivos de brasicáceas. La industria agrícola y forestal reconoce a la bacteria entomopatógena Bacillus thuringiensis (Bt como una buena alternativa biológica a los insecticidas químicos, puesto que es inocua sobre el ambiente y su toxicidad es altamente selectiva, ligada a su estrecho rango de especificidad sobre diferentes insectos plaga de los órdenes Lepidóptera, Coleóptera y Díptera. En esta revisión se presentan las posibilidades actuales que se pueden emplear para el control de la P. xylostella utilizando modelos investigativos basados en ensayos biológicos con Bt. Dichas posibilidades buscan superar las desventajas existentes en relación con la plaga P. xylostella y los cultivos de brasicáceas, además de entender la fisiología de Bt bajo condiciones que permitan incrementar la eficacia en el control biológico.

Estudo morfológico das entero-anastomoses com suturas em pontos separados complementados com adesivo sintético ou biológico em coelho Morphologic study of enteroanastomosis with sutures in separated stitches supplementeds with synthetical adhesive or biological adhesive

Directory of Open Access Journals (Sweden)

Ademir Teixeira do Amaral

2004-08-01

Full Text Available OBJETIVO: Verificar a eficácia dos adesivos de fibrina e cianoacrilato como coadjunvantes nas anastomoses de intestino delgado de coelhos. MÉTODOS: Oitenta coelhos, linhagem Nova Zelândia, machos, adultos, foram submetidos a enterectomia de 3cm e enterorrafia e distribuídos em quatro grupos: Grupo A (dois pontos eqüidistantes; Grupo B (quatro pontos eqüidistantes; Grupo C (seis pontos eqüidistantes; Grupo D (oito pontos eqüidistantes. No 14º dia de observação, os animais foram submetidos a uma laparotomia mediana para estudo macroscópico da cavidade abdominal para identificação e avaliação de aderências, deiscências e/ou fístulas. O segmento intestinal anastomosado foi retirado e feito um molde de alginato para posterior avaliação do índice de estenose. As peças retiradas foram processadas para estudo histológico e avaliação de fibras colágenas, macrófagos, neovascularização e granuloma tipo corpo estranho. RESULTADOS: Não houve diferença significante na avaliação de deiscência e fístulas com os dois adesivos entre os quatros sub-grupos. A aderência ocorreu em maior número nos sub-grupos do adesivo sintético. O índice de estenose foi maior nos animais do adesivo sintético somente nos sub-grupos com dois e oito pontos. A análise histológica mostrou que em todos os parâmetros avaliados (macrófago, neovascularização e granuloma não houve diferença significante entre os dois tipos de adesivos. Em relação a porcentagem de colágeno verificou-se que houve diferença significante somente no grupo B em que o adesivo sintético foi menor que o biológico. CONCLUSÃO: O adesivo biológico de fibrina mostra mais eficácia que o adesivo sintético como complemento de suturas nas anastomoses intestinais.PURPOSE: The aim of the research was to verify the efficacy of the fibrin or cianoacrylate glue as coadjuvant in the intestinals anastomosis of rabbits. METHODS: Eighty rabbits, lineage New Zealand, males

Promoting Diversity Through Polar Interdisciplinary Coordinated Education (Polar ICE)

Science.gov (United States)

McDonnell, J. D.; Hotaling, L. A.; Garza, C.; Van Dyk, P. B.; Hunter-thomson, K. I.; Middendorf, J.; Daniel, A.; Matsumoto, G. I.; Schofield, O.

2017-12-01

Polar Interdisciplinary Coordinated Education (ICE) is an education and outreach program designed to provide public access to the Antarctic and Arctic regions through polar data and interactions with the scientists. The program provides multi-faceted science communication training for early career scientists that consist of a face-to face workshop and opportunities to apply these skills. The key components of the scientist training workshop include cultural competency training, deconstructing/decoding science for non-expert audiences, the art of telling science stories, and networking with members of the education and outreach community and reflecting on communication skills. Scientists partner with educators to provide professional development for K-12 educators and support for student research symposia. Polar ICE has initiated a Polar Literacy initiative that provides both a grounding in big ideas in polar science and science communication training designed to underscore the importance of the Polar Regions to the public while promoting interdisciplinary collaborations between scientists and educators. Our ultimate objective is to promote STEM identity through professional development of scientists and educators while developing career awareness of STEM pathways in Polar science.

Polarization-independent broadband meta-holograms via polarization-dependent nanoholes.

Science.gov (United States)

Zhang, Xiaohu; Li, Xiong; Jin, Jinjin; Pu, Mingbo; Ma, Xiaoliang; Luo, Jun; Guo, Yinghui; Wang, Changtao; Luo, Xiangang

2018-05-17

Composed of ultrathin metal or dielectric nanostructures, metasurfaces can manipulate the phase, amplitude and polarization of electromagnetic waves at a subwavelength scale, which is promising for flat optical devices. In general, metasurfaces composed of space-variant anisotropic units are sensitive to the incident polarization due to the inherent polarization dependent geometric phase. Here, we implement polarization-independent broadband metasurface holograms constructed by polarization-dependent anisotropic elliptical nanoholes by elaborate design of complex amplitude holograms. The fabricated meta-hologram exhibits a polarization insensitive feature with an acceptable image quality. We verify the feasibility of the design algorithm for three-dimensional (3D) meta-holograms with simulation and the feasibility for two-dimensional (2D) meta-holograms is experimentally demonstrated at a broadband wavelength range from 405 nm to 632.8 nm. The effective polarization-independent broadband complex wavefront control with anisotropic elliptical nanoholes proposed in this paper greatly promotes the practical applications of the metasurface in technologies associated with wavefront manipulation, such as flat lens, colorful holographic displays and optical storage.

Ciclos reais brasileiros em dois setores

Directory of Open Access Journals (Sweden)

Fabio Kanczuk

2004-03-01

Full Text Available Construímos um modelo de equilíbrio geral dinâmico de dois setores com o intuito de investigar o comportamento dos ciclos reais brasileiros. Quando os investimentos dos dois setores são agregados de acordo com uma Cobb-Douglas para formação de capital, o modelo é consistente com as volatilidades cíclicas dos componentes das contas nacionais e com a natureza contracíclica das exportações líquidas e do câmbio real. Caso a elasticidade de substituição entre o consumo de comercializáveis e de não comercializáveis seja baixa, o modelo também reproduz a volatilidade observada no câmbio real.We construct a two-sector dynamic general equilibrium model to investigate the behavior of the Brazilian business cycles. When investments from each sector are aggregated according to a Cobb-Douglas for capital formation, the model is consistent with the cyclical volatilities of national income components as well as with the countercyclical character of net exports and real exchange rates. If the elasticity of substitution between consumptions of tradeables and non-tradeables is low, the model can also reproduce the observed real exchange rates volatilities.

DNA binding polarity, dimerization, and ATPase ring remodeling in the CMG helicase of the eukaryotic replisome

Science.gov (United States)

Costa, Alessandro; Renault, Ludovic; Swuec, Paolo; Petojevic, Tatjana; Pesavento, James J; Ilves, Ivar; MacLellan-Gibson, Kirsty; Fleck, Roland A; Botchan, Michael R; Berger, James M

2014-01-01

The Cdc45/Mcm2-7/GINS (CMG) helicase separates DNA strands during replication in eukaryotes. How the CMG is assembled and engages DNA substrates remains unclear. Using electron microscopy, we have determined the structure of the CMG in the presence of ATPγS and a DNA duplex bearing a 3′ single-stranded tail. The structure shows that the MCM subunits of the CMG bind preferentially to single-stranded DNA, establishes the polarity by which DNA enters into the Mcm2-7 pore, and explains how Cdc45 helps prevent DNA from dissociating from the helicase. The Mcm2-7 subcomplex forms a cracked-ring, right-handed spiral when DNA and nucleotide are bound, revealing unexpected congruencies between the CMG and both bacterial DnaB helicases and the AAA+ motor of the eukaryotic proteasome. The existence of a subpopulation of dimeric CMGs establishes the subunit register of Mcm2-7 double hexamers and together with the spiral form highlights how Mcm2-7 transitions through different conformational and assembly states as it matures into a functional helicase. DOI: http://dx.doi.org/10.7554/eLife.03273.001 PMID:25117490

Ride the wave

DEFF Research Database (Denmark)

Sørensen, Jakob B

2017-01-01

The functions of four of the five proteins in the mammalian uncoordinated-13 (Munc13) family have been identified as priming factors in SNARE-dependent exocytosis. In this issue, Zhang et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201702099) show that the fifth member, BAIAP3 (brain...

Guilt by association

DEFF Research Database (Denmark)

Perez-Moreno, Mirna; Fuchs, Elaine

2012-01-01

Members of the p120-catenin family associate with cadherins and regulate their stability at the plasma membrane. How p120-catenin limits cadherin endocytosis has long remained a mystery. In this issue, Nanes et al. (2012. J. Cell Biol. doi:10.1083/jcb.201205029) identify a conserved acidic motif ...

Estudio del Efecto de Acciones Químicas y Biológicas sobre la Masa Panaria

OpenAIRE

Bot, Beatriz Rosalía Ida

2010-01-01

El pan es un producto de consumo masivo al que se le suelen agregar a los ingredientes básicos (harina, agua, levadura y sal) oxidantes, emulsionantes, conservantes, entre otros, para mejorar la calidad del producto. La fermentación es relevante en las características del pan, es realizado por levaduras biológicas ya sean de producción industrial (cepa pura de Saccharomyces cereviceae), o de producción artesanal (masa madre). En el presente trabajo se estudió el efecto d...

Surface Tension of Binary Mixtures Including Polar Components Modeled by the Density Gradient Theory Combined with the PC-SAFT Equation of State

Czech Academy of Sciences Publication Activity Database

Vinš, Václav; Planková, Barbora; Hrubý, Jan

2013-01-01

Roč. 34, č. 5 (2013), s. 792-812 ISSN 0195-928X R&D Projects: GA AV ČR IAA200760905; GA ČR(CZ) GPP101/11/P046; GA ČR GA101/09/1633 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : chemical polarity * gradient theory * surface tension Subject RIV: BJ - Thermodynamics Impact factor: 0.623, year: 2013 http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.1007/s10765-012-1207-z

Polarization digital holographic microscopy using low-cost liquid crystal polarization rotators

Science.gov (United States)

Dovhaliuk, Rostyslav Yu

2018-02-01

Polarization imaging methods are actively used to study anisotropic objects. A number of methods and systems, such as imaging polarimeters, were proposed to measure the state of polarization of light that passed through the object. Digital holographic and interferometric approaches can be used to quantitatively measure both amplitude and phase of a wavefront. Using polarization modulation optics, the measurement capabilities of such interference-based systems can be extended to measure polarization-dependent parameters, such as phase retardation. Different kinds of polarization rotators can be used to alternate the polarization of a reference beam. Liquid crystals are used in a rapidly increasing number of different optoelectronic devices. Twisted nematic liquid crystals are widely used as amplitude modulators in electronic displays and light valves or shutter glass. Such devices are of particular interest for polarization imaging, as they can be used as polarization rotators, and due to large-scale manufacturing have relatively low cost. A simple Mach-Zehnder polarized holographic setup that uses modified shutter glass as a polarization rotator is demonstrated. The suggested approach is experimentally validated by measuring retardation of quarter-wave film.

Cirugía biológica pre protésica en artrosis temprana de rodilla

Directory of Open Access Journals (Sweden)

Wainer E. Mauricio, DR

2014-09-01

Full Text Available La artrosis (OA de rodilla es una condición progresiva, incapacitante en distintos grados en sus etapas, terminando en el colapso y destrucción articular que requiere de cirugía protésica en las etapas más avanzadas. La cirugía biológica pre-protésica, concepto que hoy en día se implementa en el manejo de las etapas precoces de la OA, se basa en el diagnóstico precoz de esta condición y de los factores de riesgo que aseguran el progreso a estados más avanzados. Su objetivo es prolongar la vida útil de la articulación nativa y retardar o eliminar la necesidad de una prótesis de rodilla. Esto ha motivado innumerables estudios preclínicos y clínicos en base al uso de nuevos elementos de ingeniería de tejidos, uso de implantes de condrocitos autólogos y manejo de células madre. Los resultados en el corto y mediano plazo son auspiciosos, pero se requieren mejores niveles de evidencia científica de estos estudios y seguimientos más prolongados. En el presente artículo se analiza el concepto de la artrosis temprana, la detección de las lesiones de cartílago y los factores de riesgo de los pacientes que los llevan a una artrosis y los protocolos actuales de tratamiento biológico de Clínica Las Condes.

Juicios morales y fronteras biológicas: más allá de la frontera razón / emoción

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Cabezas, Mar

2013-08-01

Full Text Available We build boundaries that are theoretically based on biological grounds and we derive moral judgments from them. Likewise, we take for granted that emotions such as fear, disgust or rage were the element that led us to this mistake, especially when we realise the logical inconsistency of deriving moral judgments in this way. Consequently, we often associate emotions with prejudices, beliefs or fallacies, which we ought to free ourselves from. However, emotions are not the cause of the problem. Firstly, because the classical dichotomical framework that defends the reason/emotion polarity is also questionable. Secondly, because emotions, as alarms which transmit important information, may be a key element in the discovery and overcoming of the discriminations that arise at the boundaries of dichotomies. Thus, the aim here is to analyse the relationship between these three elements: biological boundaries, moral judgments and emotions. And then toargue in favour of the links between reason and emotions as a way of surpassing the old dichotomic model, and, to conclude, I will point out some of the benefits of replacing a dualistic framework by an interactive one.Construimos fronteras con supuesta base biológica y derivamos juicios morales de ellas. Asimismo, suponemos que fueron nuestras emociones —el miedo, el asco o la rabia— las que nos llevaron a tal error, especialmente cuando nos damos cuenta de la inconsistencia lógica de derivar juicios morales de dichas fronteras. En consecuencia, solemos identificar emociones con prejuicios, creencias u opciones falaces de las que más nos valdría librarnos. Sin embargo, como se tratará de argumentar a continuación, las emociones no son la causa del problema. Primero, porque el marco conceptual clásico dicotómico en el que razón y emoción son dos polos opuestos regidos por una tensión irreconciliable es a su vez cuestionable. Segundo, porque las emociones, en cuanto alarmas transmisoras de

Acidente com material biológico entre trabalhadores da área de expurgo em centros de material e esterilização - DOI: 10.4025/actascihealthsci.v26i2.1577 Accident with biological material with workers of expurgation area in central supply - DOI: 10.4025/actascihealthsci.v26i2.1577

Directory of Open Access Journals (Sweden)

Shellen Bueno de Souza

2004-04-01

Full Text Available A limpeza dos artigos odonto-médico-hospitalares realizada por métodos manuais aumenta o risco de acidentes com material biológico. Foram objetivos deste estudo caracterizar os acidentes envolvendo exposição a material biológico entre trabalhadores de expurgos; identificar a freqüência da subnotificação dos acidentes e descrever as medidas de prevenção adotadas. Após aprovação em comitê de ética e consentimento dos trabalhadores, os dados foram coletados mediante entrevista com 111 trabalhadores de Centros de Material e Esterilização de hospitais da cidade de Goiânia, Estado de Goiás. Evidenciou-se que (33 29,8% dos profissionais relataram ter sofrido acidentes, destes (24 72,7% foram notificados e nove (27,3% não foram. A maioria (92,8% não soube citar os Equipamentos de Proteção Individual indicados para uso no expurgo. Os acidentes foram, predominantemente, ocasionados por objetos perfurocortantes, envolvendo membros superiores. Concluiu-se que a maioria dos profissionais não adere às medidas preventivas, o que os expõem a situações de risco que se agravam quando os acidentes não são notificados.The cleaning of odonto-medical-hospital articles made by handy methods increases the risk of accidents with biological material. This article has as purposes: to characterize accidents involving the exposure of expurgation’s workers to biological material; to identify the incidence of accident’s subnotifications and to describe the prevention’s steps chosen. After the approval of an Ethics Committee and the worker’s permission, the data were collected in an interview with 111 workers of Central Supply. These employers work in hospitals with a hundred or more beds, located in Goiânia-GO. The article showed that (33 29,8% of the workers listened said that they had accidents. Among these accidents, (24 72,7% were notified and nine woren’t. The majority of the workers, 92,8%, didn´t know the individual

“Tomar” e “Zona Monumental de Ajuda Belem”. Dois projectos de salvaguardia, dois casos de estudo

Directory of Open Access Journals (Sweden)

Isabel Maria Augusto de Sousa Rosa

2008-12-01

Full Text Available Prosseguindo os propósitos deste Il Seminário internacional “Conservazione del Património Arquitectónico e Urbano”, onde irão ser confrontadas as experiências realizadas em Itália e Portugal no âmbito da conservação do património arquitectónico e urbano, são apresentados dois casos de estudo, objectivando a salvaguarda dos centros históricos, realizados em duas cidades portuguesas - Tomar (Centro Histórico e Lisboa (Zona Monumental Ajuda-Belém. Os dois Planos então realizados – Tomar, em 1996, e zona monumental Ajuda-Belém, em 2004 – ambos recorrendo a suporte informático, evidenciam na “decalage” de 8 anos, a importância dos avanços tecnológicos e informáticos, patente no projecto mais recente (Zona Monumental Ajuda - Belém, quer na aquisição e processamento de dados, quer ainda na consulta dos mesmos, processos que se têm revelado valiosíssimos para a conservação e salvaguarda do património arquitectónico, urbano e ambiental desta zona da cidade de Lisboa.

Propuestas para una gestión de la diversidad biológica del Perú

OpenAIRE

Vilchez Navarro, María Hortensia; Vilchez Navarro, María Hortensia

2004-01-01

El presente documento representa un esfuerzo por encontrar alternativas para mejorar la gestión de la diversidad biológica del Perú desde de una perspectiva global, procurando integrar conservación y desarrollo, bajo el enfoque del desarrollo sostenible. El trabajo consta de cuatro partes que se desarrollan en 14 capítulos. La Primera parte aborda aspectos relativos a los objetivos, la metodología de investigación y el marco teórico que sirven de base para la comprensión de la gestión de la b...

Disease: H00056 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H00056 Alzheimer's disease (AD) Alzheimer's disease (AD) is a chronic disorder tha...sak JM, Holtzman DM ... TITLE ... The role of apolipoprotein E in Alzheimer's disease. ... JOURNAL ... Neuron 63:2...87-303 (2009) DOI:10.1016/j.neuron.2009.06.026 ... PMID:18802446 ... AUTHORS ... Bertram L, Tanzi RE ... TITLE ... Thirty years of Alzheimer...Cacabelos R ... TITLE ... Pharmacogenomics in Alzheimer's disease. ... JOURNAL ... Methods Mol Biol 448:213-357 (2...008) DOI:10.1007/978-1-59745-205-2_10 ... PMID:17082447 ... AUTHORS ... Goedert M, Spillantini MG ... TITLE ... A century of Alzheimer

PRIMEIRA OCORRÊNCIA DE Lutzomyia (Lutzomyia) longipalpis LUTZ & NEIVA, 1912 (DIPTERA: PSYCHODIDAE: PHLEBOTOMINAE) NO ESTADO DO AMAPÁ, BRASIL.

OpenAIRE

Allan Kardec Ribeiro Galardo; Clicia Denis Galardo; Aderbal Amanajás Santana; José Claudio Cortes Mendes; Francisco Redivaldo Almeida de Souza; Jorge Pereira Duarte; José Ferreira Saraiva; Luiz Carlos Leite Pinna; Raimundo Wilson Carvalho; Ana Paula Sales de Andrade Correa; Ana Cristina da Silva Ferreira Lima

2013-01-01

Relata-se a primeira ocorrência de Lutzomyia longipalpis, o mais importante vetor biológico do agente causador da Leishmaniose Visceral Americana (LVA), no município de Ferreira Gomes, estado do Amapá, Brasil e por tratar-se de uma espécie com grande importância epidemiológica, os autores alertam as autoridades locais.   Palavras-chave: Amapá, Ferreira Gomes, Lutzomyia longipalpis, Leishmaniose Visceral Americana.   DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v3n2p179-...

Polarization holography

DEFF Research Database (Denmark)

Nikolova, L.; Ramanujam, P.S.

Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

Recubrimientos de pisos en áreas controladas de la producción de biológicos

Directory of Open Access Journals (Sweden)

Pedro A. Rodríguez

2007-12-01

Full Text Available El recubrimiento de los pisos, utilizando las resinas sintéticas autonivelantes en la construcción de las áreas controladas, empleadas en las instalaciones de producción de biológicos, en las dedicadas a los procesos de manipulación de microorganismos (contención, así como en las instalaciones para los animales de laboratorio y procesos asépticos de formulación farmacéutica, contribuyen a la seguridad biológica y farmacéutica, según sea el caso, por su continuidad integral y garantía de la calidad microbiológica del aire, así como al ahorro energético, pues disminuyen la ganancia de calor latente atribuido a la humedad incorporada al aire por otros recubrimientos permeables. Las condiciones climáticas de Cuba y la dureza del agua empleada en las mezclas cementosas son un alto potencial para la formación de "burbujas", tema abordado en este trabajo. El conocimiento de los aspectos que provocan la formación de estas ampollas y las vías para evitarlo, son útiles y de un valor apreciable. En este artículo se presentan las experiencias obtenidas con la aplicación de los recubrimientos epoxídicos en las áreas controladas del Instituto Finlay, instalaciones que no han presentado deformaciones apreciables después de 15 años de explotación.

Acidentes com material biológico relacionados ao trabalho: análise de uma abordagem institucional

Directory of Open Access Journals (Sweden)

Ana Isabel Dias da Silva

Full Text Available RESUMO OBJETIVO: analisar o perfil de relatórios, instrumentos de registros e fluxos de tratamento, notificações, acompanhamentos, profilaxias e encaminhamentos devidos a acidentes causados por material perfurocortante em trabalhadores de saúde em uma instituição de saúde pública. Métodos: a coleta de dados usou um questionário semiestruturado aplicado aos profissionais responsáveis pelos registros de acidentes e avaliou os formulários utilizados em três setores da instituição de estudo. RESULTADOS: foram analisados 134 registros de acidentes biológicos. Quando comparamos os registros da instituição com os 50 registrados no mesmo período pelo banco de dados da Secretaria Municipal de Saúde do Rio de Janeiro, apenas 11 casos foram concordantes. Também identificamos falta de padronização nos formulários utilizados, fluxos diferentes e falta de registros de investigações dos casos, além de ausência de acompanhamento do desfecho dos acidentes. CONCLUSÃO: constataram-se subnotificação e discordância entre as fontes. Um formulário de registro para acidentes biológicos foi elaborado para informações de notificação e investigações, bem como criado um programa para monitorar acidentes causados por material perfurocortante, visando melhorar a vigilância de saúde dos trabalhadores da instituição.

Reflexia na stav a perspektívy didaktiky biológie z pohľadu situácie na Prírodovedeckej fakulte Univerzity Komenského v Bratislave.

Directory of Open Access Journals (Sweden)

Katarína Ušáková

2014-12-01

Full Text Available Príspevok popisuje východiská a impulzy rozvoja didaktiky biológie na Slovensku  z pohľadu skúseností edukačnej a výskumnej práce na Katedre didaktiky prírodných vied, psychológie a pedagogiky PRIFUK v Bratislave. Cez stručný historický prehľad od povojnového obdobia až po súčasnosť upriamuje pozornosť na osobnosti, ktoré sú s formovaním didaktiky biológie úzko spojené. Poukazuje na niektoré spoločné problémy prírodovedného vzdelávania v kontexte spoločensko-politických zmien spojených so vstupom do EU a dôsledkami reformného úsilia s cieľom konvergencie vzdelávacích systémov krajín EU. Podrobnejšie sa venuje problémom v doktorandskom štúdiu  a výskumu v didaktike biológie, od kvality ktorého sa odvíja aj úroveň učiteľskej prípravy budúcich učiteľov biológie. Konkretizuje zmeny v obsahu aj v štruktúre didaktických predmetov s cieľom zvýšiť kvalitu a funkčnosť prípravy učiteľov. V závere príspevku autorka upozorňuje na pretrvávajúce problémy didaktiky biológie, ktorých riešenie si vyžaduje potrebu vyššej miery spolupráce všetkých zainteresovaných zložiek.

Polarized neutron spectrometer

International Nuclear Information System (INIS)

Abov, Yu.G.; Novitskij, V.V.; Alfimenkov, V.P.; Galinskij, E.M.; Mareev, Yu.D.; Pikel'ner, L.B.; Chernikov, A.N.; Lason', L.; Tsulaya, V.M.; Tsulaya, M.I.

2000-01-01

The polarized neutron spectrometer, intended for studying the interaction of polarized neutrons with nuclei and condensed media in the area of energies from thermal up to several electron-volt, is developed at the IBR-2 reactor (JINR, Dubna). Diffraction on the Co(92%)-Fe(8%) magnetized monocrystals is used for the neutron polarization and polarization analysis. The neutron polarization within the whole energy range equals ∼ 95% [ru

Nuestra variedad lingüística como variedad biológica

Directory of Open Access Journals (Sweden)

Danilo Salamanca

2014-05-01

Full Text Available El estudio se centra en señalar problemas esenciales sobre las consecuencias culturales ante la pérdida de idiomas ancestrales, en particular referido al patrimonio lingüístico indígena centroamericano. Señala algunas relaciones entre este proceso y las discusiones sobre la protección de los ecosistemas biológicos de la región, y llama la atención sobre las políticas que existen o deberían existir, para recuperar y preservar tanto el componente cultural (los idiomas como el natural. This study examines essential problems related to the cultural consequences due to the loss of ancestral languages, especially Central American Indigenous languages. It mentions relationships between this process and discussions about the protection of biological ecosystems in the region, and addresses policies that exist, or should exist, to recover and preserve both cultural (linguistic and natural components.

Sobre figuras de oposição em dois sonetos de Camões

OpenAIRE

Marnoto, Rita

2012-01-01

(2012). Sobre figuras de oposição em dois sonetos de Camões. In Rita Marnoto (Coord.), Comentário a Camões. Vol. 1. Sonetos (147-204). Lisboa: CIEC, Cotovia. ISBN 978 972 795 330 1 figuras de oposição, visão histórica e seu uso em dois sonetos de Camões

PolarTrack: Optical Outside-In Device Tracking that Exploits Display Polarization

DEFF Research Database (Denmark)

Rädle, Roman; Jetter, Hans-Christian; Fischer, Jonathan

2018-01-01

PolarTrack is a novel camera-based approach to detecting and tracking mobile devices inside the capture volume. In PolarTrack, a polarization filter continuously rotates in front of an off-the-shelf color camera, which causes the displays of observed devices to periodically blink in the camera feed....... The periodic blinking results from the physical characteristics of current displays, which shine polarized light either through an LC overlay to produce images or through a polarizer to reduce light reflections on OLED displays. PolarTrack runs a simple detection algorithm on the camera feed to segment...... displays and track their locations and orientations, which makes PolarTrack particularly suitable as a tracking system for cross-device interaction with mobile devices. Our evaluation of PolarTrack's tracking quality and comparison with state-of-the-art camera-based multi-device tracking showed a better...

Las tecnologías de integración como estructuras biológicas. Establecimiento de un modelo general

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C. de la Torre Cuesta

2000-01-01

Full Text Available Las Tecnolog´ıas de Integraci´on, se ocupan del almacenamiento, transporte y distribuci´on de la informaci´on generada en la sociedad humana,por lo que conviene destacar el papel que dicha informaci´on desempe˜na en la propia estructura de la sociedad y su importancia en la evoluci´on de la misma, siendo las personas un elemento fundamental y critico para su transmisi´on La transmisi´on de las Tecnolog´ıas de Integraci´on, es comparable al de los sistemas biol´ogicos, que se propaga a los individuos del sistema considerado. En esta comunicaci´on, partiendo de una clasificaci´on de la poblaci´on en cinco categor´ıas: Expertos, Activos, Predispuestos, Dudosos y Eliminados, se establece un diagrama compartimental general de la transmisi´on de las tecnolog´ıas, consideradas como un efecto biol´ogico, estableciendo relaciones entre los distintos estados de la poblaci´on. Posteriormente, utilizando la teor´ıa de los sistemas din´amicos no lineales establecer los aspectos para la estructuraci´on temporal, y as´ı desarrollar el modelo matem´atico establecido.

Uso correcto del español en la redacción de artículos biológicos

Directory of Open Access Journals (Sweden)

Julián Monge-Nájera

2008-12-01

Full Text Available Presentamos una lista de los errores más comunes en los manuscritos biológicos redactados en lengua española, explicando cuáles son las palabras recomendadas. Nos basamos en las recomendaciones de la Real Academia Española y los Códigos Internacionales de Nomenclatura, así como en las normas del Consejo de Editores Científicos. Agrupamos las correcciones y recomendaciones en cuatro categorías: léxico (e.g. anglicismos, ortografía (acentuación gráfica, puntuación, mayúsculas, morfología (régimen preposicional y estilo (economía lingüística.Correct use of Spanish when writing biological papers. We present a list of the most frequent errors in biological manuscripts written in Spanish, and we explain which are the recommended options. Our article is based on the International Codes of Nomenclature, and the guidelines of the Real Academia de la Lengua and the Council of Science Editors. We group the indications in four categories: lexical errors (e.g. English cognates; spelling (graphic accents, punctuation, font, morphology (use of prepositions and style (linguistic economy. Rev. Biol. Trop. 56 (4: 1589-1593. Epub 2008 December 12.

Lunar true polar wander inferred from polar hydrogen.

Science.gov (United States)

Siegler, M A; Miller, R S; Keane, J T; Laneuville, M; Paige, D A; Matsuyama, I; Lawrence, D J; Crotts, A; Poston, M J

2016-03-24

The earliest dynamic and thermal history of the Moon is not well understood. The hydrogen content of deposits near the lunar poles may yield insight into this history, because these deposits (which are probably composed of water ice) survive only if they remain in permanent shadow. If the orientation of the Moon has changed, then the locations of the shadowed regions will also have changed. The polar hydrogen deposits have been mapped by orbiting neutron spectrometers, and their observed spatial distribution does not match the expected distribution of water ice inferred from present-day lunar temperatures. This finding is in contrast to the distribution of volatiles observed in similar thermal environments at Mercury's poles. Here we show that polar hydrogen preserves evidence that the spin axis of the Moon has shifted: the hydrogen deposits are antipodal and displaced equally from each pole along opposite longitudes. From the direction and magnitude of the inferred reorientation, and from analysis of the moments of inertia of the Moon, we hypothesize that this change in the spin axis, known as true polar wander, was caused by a low-density thermal anomaly beneath the Procellarum region. Radiogenic heating within this region resulted in the bulk of lunar mare volcanism and altered the density structure of the Moon, changing its moments of inertia. This resulted in true polar wander consistent with the observed remnant polar hydrogen. This thermal anomaly still exists and, in part, controls the current orientation of the Moon. The Procellarum region was most geologically active early in lunar history, which implies that polar wander initiated billions of years ago and that a large portion of the measured polar hydrogen is ancient, recording early delivery of water to the inner Solar System. Our hypothesis provides an explanation for the antipodal distribution of lunar polar hydrogen, and connects polar volatiles to the geologic and geophysical evolution of the Moon

Estudio de procesos biológicos de tratamiento de residuos basado en la modelización

OpenAIRE

Magrí Aloy, Albert; Flotats Ripoll, Xavier; Solé-Mauri, Francina; Illa Alibes, Josep

2006-01-01

Los modelos matemáticos se han convertido en una herramienta básica para aumentar la comprensión de los procesos biológicos relacionados con el tratamiento de residuos orgánicos. En este sentido, la modelación permite crear un lenguaje de comunicación común, orientar el diseño experimental, evaluar resultados, contrastar hipótesis, revelar relaciones entre variables, prever la evolución de sistemas y, en definitiva, diseñar estrategias de gestión y tratamiento op...

Polarized proton beams

International Nuclear Information System (INIS)

Roser, T.

1995-01-01

The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

KRS : A cut away from release in exosomes

NARCIS (Netherlands)

Rabouille, Catherine

2017-01-01

Cancer cells often trigger an inflammatory process, which in some cases may be driven by the presence of lysyltRNA synthetase (KRS) in the medium. Kim et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201605118) now demonstrate that cleavage of the KRS by caspase-8 inside cells triggers its

A novel method to calibrate DOI function of a PET detector with a dual-ended-scintillator readout

International Nuclear Information System (INIS)

Shao Yiping; Yao Rutao; Ma Tianyu

2008-01-01

The detection of depth-of-interaction (DOI) is a critical detector capability to improve the PET spatial resolution uniformity across the field-of-view and will significantly enhance, in particular, small bore system performance for brain, breast, and small animal imaging. One promising technique of DOI detection is to use dual-ended-scintillator readout that uses two photon sensors to detect scintillation light from both ends of a scintillator array and estimate DOI based on the ratio of signals (similar to Anger logic). This approach needs a careful DOI function calibration to establish accurate relationship between DOI and signal ratios, and to recalibrate if the detection condition is shifted due to the drift of sensor gain, bias variations, or degraded optical coupling, etc. However, the current calibration method that uses coincident events to locate interaction positions inside a single scintillator crystal has severe drawbacks, such as complicated setup, long and repetitive measurements, and being prone to errors from various possible misalignments among the source and detector components. This method is also not practically suitable to calibrate multiple DOI functions of a crystal array. To solve these problems, a new method has been developed that requires only a uniform flood source to irradiate a crystal array without the need to locate the interaction positions, and calculates DOI functions based solely on the uniform probability distribution of interactions over DOI positions without knowledge or assumption of detector responses. Simulation and experiment have been studied to validate the new method, and the results show that the new method, with a simple setup and one single measurement, can provide consistent and accurate DOI functions for the entire array of multiple scintillator crystals. This will enable an accurate, simple, and practical DOI function calibration for the PET detectors based on the design of dual-ended-scintillator readout. In

Ratos isogênicos F344 como modelo biológico de sepsis intra-abdominal

Directory of Open Access Journals (Sweden)

Sueli Blanes Damy

2002-01-01

Full Text Available Com o objetivo de estudar um modelo biológico de sepsis intra-abdominal aguda para estudos experimentais, foram infectados ratos isogênicos F344, convencionais, com a bactéria Escherichia coli (E.coli, cepa ATCC 11775, sorotipo H7:O1:K1. Os animais inoculados, machos e fêmeas, apresentaram 6 horas após a inoculação por E.coli os seguintes sintomas: arqueamento do dorso, piloereção, hiperpnéia e diminuição das atividades motoras. A dose que produziu 50% de mortalidade (DL50 após 7 dias, determinada pelo método Reed & Muench, foi de 6 x 10(5 CFU/ml (analisado em 32 machos e 32 fêmeas. A maior concentração de mortalidade foi observada nas primeiras 24 horas. A disfunção hepática, comum em sepsis intra-abdominal, foi avaliada por provas enzimáticas, em 0, 24, 48 e 168 horas após a inoculação. O estudo da migração de células polimorfonucleares-neutrófilos (PMN e mononucleares-macrófagos (MN apontou um aumento significante de PMN entre o grupos de machos (z ³ 4,7; p < 0,003 e de fêmeas (z ³ 6,2; p < 0,0003 inoculados E.coli, quando comparados ao grupos controles. Quanto às células MN, não houve diferença entre os grupos inoculados e os controles, tanto para os machos (z=2,3; p = 0,0107, como para as fêmeas (z=1,8; p =0,0359. Em conclusão, estes resultados demonstram que os ratos isogênicos F344 são modelos biológicos adequados para estudos de sepsis intra-abdominal aguda.

Estudios fisicoqu??micos y biol??gicos de un nuevo derivado de la eritromicina: el folato de eritromicina

OpenAIRE

Manna, P.K.; Kumaran, V.; Mohanta, G.P.

2005-01-01

Se prepar?? un derivado nuevo de la eritromicina, el folato de eritromicina, y se evaluaron sus propiedades fisicoqu??micas y biol??gicas. El derivado presenta una buena solubilidad en metanol, etanol y propileno glicol. Los valores de los coeficientes de partici??n, que fueron 1,12 y 1,10 en sistemas de cloroformo/agua y octanol/agua respectivamente, indican que probablemente se distribuya bien in vivo. La potencia in vitro del derivado, 716 ??g/mg, es mayor que la de derivados e...

Charge transport in non-polar and semi-polar III-V nitride heterostructures

International Nuclear Information System (INIS)

Konar, Aniruddha; Verma, Amit; Fang, Tian; Zhao, Pei; Jana, Raj; Jena, Debdeep

2012-01-01

Compared to the intense research focus on the optical properties, the transport properties in non-polar and semi-polar III-nitride semiconductors remain relatively unexplored to date. The purpose of this paper is to discuss charge-transport properties in non-polar and semi-polar orientations of GaN in a comparative fashion to what is known for transport in polar orientations. A comprehensive approach is adopted, starting from an investigation of the differences in the electronic bandstructure along different polar orientations of GaN. The polarization fields along various orientations are then discussed, followed by the low-field electron and hole mobilities. A number of scattering mechanisms that are specific to non-polar and semi-polar GaN heterostructures are identified, and their effects are evaluated. Many of these scattering mechanisms originate due to the coupling of polarization with disorder and defects in various incarnations depending on the crystal orientation. The effect of polarization orientation on carrier injection into quantum-well light-emitting diodes is discussed. This paper ends with a discussion of orientation-dependent high-field charge-transport properties including velocity saturation, instabilities and tunneling transport. Possible open problems and opportunities are also discussed. (paper)

DOI criticized for failing to inventory hazardous waste sites on federal lands

International Nuclear Information System (INIS)

Anon.

1993-01-01

The Department of the Interior (DOI) manages approximately 440 million acres of public land across the United States, including national parks and forests, wildlife refuges, fish hatcheries, and water and hydroelectric projects. At these facilities, hazardous wastes are commonly generated through such activities as oil and gas drilling, coal mining, hydroelectric plant operation, and pesticide application. Consequently, a significant number of DOI sites are probably contaminated and thus must be identified, assessed, and remediated. 2 refs., 1 tab

2D imaging simulations of a small animal PET scanner with DOI measurement. jPET-RD

International Nuclear Information System (INIS)

Yamaya, Taiga; Hagiwara, Naoki

2005-01-01

We present a preliminary study on the design of a high sensitivity small animal depth of interaction (DOI)-PET scanner: jPET-RD (for Rodents with DOI detectors), which will contribute to molecular imaging. The 4-layer DOI block detector for the jPET-RD that consists of scintillation crystals (1.4 mm x 1.4 mm x 4.5 mm) and a flat panel position-sensitive photomultiplier tube (52 mm x 52 mm) was previously proposed. In this paper, we investigate imaging performance of the jPET-RD through numerical simulations. The scanner has a hexagonal geometry with a small diameter and a large axial aperture. Therefore DOI information is expected to improve resolution uniformity in the whole field of view (FOV). We simulate the scanner for various parameters of the number of DOI channels and the crystal length. Simulated data are reconstructed using the maximum likelihood expectation maximization with accurate system modeling. The trade-off results between background noise and spatial resolution show that only shortening the length of crystal does not improve the trade-off at all, and that 4-layer DOI information improves uniformity of spatial resolution in the whole FOV. Excellent performance of the jPET-RD can be expected based on the numerical simulation results. (author)

Polarization-sensitive color in butterfly scales: polarization conversion from ridges with reflecting elements.

Science.gov (United States)

Zhang, Ke; Tang, Yiwen; Meng, Jinsong; Wang, Ge; Zhou, Han; Fan, Tongxiang; Zhang, Di

2014-11-03

Polarization-sensitive color originates from polarization-dependent reflection or transmission, exhibiting abundant light information, including intensity, spectral distribution, and polarization. A wide range of butterflies are physiologically sensitive to polarized light, but the origins of polarized signal have not been fully understood. Here we systematically investigate the colorful scales of six species of butterfly to reveal the physical origins of polarization-sensitive color. Microscopic optical images under crossed polarizers exhibit their polarization-sensitive characteristic, and micro-structural characterizations clarify their structural commonality. In the case of the structural scales that have deep ridges, the polarization-sensitive color related with scale azimuth is remarkable. Periodic ridges lead to the anisotropic effective refractive indices in the parallel and perpendicular grating orientations, which achieves form-birefringence, resulting in the phase difference of two different component polarized lights. Simulated results show that ridge structures with reflecting elements reflect and rotate the incident p-polarized light into s-polarized light. The dimensional parameters and shapes of grating greatly affect the polarization conversion process, and the triangular deep grating extends the outstanding polarization conversion effect from the sub-wavelength period to the period comparable to visible light wavelength. The parameters of ridge structures in butterfly scales have been optimized to fulfill the polarization-dependent reflection for secret communication. The structural and physical origin of polarization conversion provides a more comprehensive perspective on the creation of polarization-sensitive color in butterfly wing scales. These findings show great potential in anti-counterfeiting technology and advanced optical material design.

Timing resolution improvement using DOI information in a four-layer scintillation detector for TOF-PET

Energy Technology Data Exchange (ETDEWEB)

Shibuya, Kengo [jPET Project Team, Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-0024 (Japan)], E-mail: shibuken@gakushikai.jp; Nishikido, Fumihiko [jPET Project Team, Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-0024 (Japan); Tsuda, Tomoaki [Technology Research Laboratory, Shimadzu Corporation, Hikaridai 3-9-4, Seika-cho, Kyoto 619-0237 (Japan); Kobayashi, Tetsuya [Department of Medical System Engineering, Graduate School of Engineering, Chiba University, Yayoi 1-33, Inage-ku, Chiba 263-8522 (Japan); Lam, Chihfung; Yamaya, Taiga; Yoshida, Eiji; Inadama, Naoko; Murayama, Hideo [jPET Project Team, Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-0024 (Japan)

2008-08-11

Depth-of-interaction (DOI) detectors are considered to be advantageous for time-of-flight positron emission tomography (TOF-PET) because they can correct timing errors arising in the scintillation crystals due to a propagation speed difference between annihilation radiation and scintillation photons. We experimentally measured this timing error, using our four-layer DOI encoding method. The upper layers exhibited the larger timing delays due to the longer path lengths after conversion from annihilation radiation into scintillation photons that traveled by zigzag paths at a speed decreased by a factor of the refractive index (n). The maximum timing delay between the uppermost and the lowermost layers was evaluated as 164 ps when n=1.47. A TOF error correction was demonstrated to improve the timing resolution of the four-layer DOI detector by 10.3%, which would increase the effective sensitivity of the scanner by about 12% comparison with a non-DOI TOF-PET scanner. This is the first step towards combining these two important fields in PET instrumentation, namely DOI and TOF, for the purpose of achieving a higher sensitivity as well as a more uniform spatial resolution.

System for measuring the proton polarization in a polarized target

International Nuclear Information System (INIS)

Karnaukhov, I.M.; Lukhanin, A.A.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

1984-01-01

The system for measuring the proton polarization in a polarized target representing the high-sensitivity nuclear magnetic resonance (NMR) is described Q-meter with series connection and a circuit for measuring system resonance characteristic is used for NMR-absorption signal recording. Measuring coil is produced of a strip conductor in order to obtain uniform system sensitivity to polarization state in all target volume and improve signal-to-noise ratio. Polarization measuring system operates ion-line with the M-6000 computer. The total measuring error for the value of free proton polarization in target taking into account the error caused by local depolarization of working substance under irradiation by high-intense photon beam is <= 6%. Long-term application of the described system for measuring the proton polarization in the LUEh-20000 accelerator target used in the pion photoproduction experiments has demonstrated its high reliability

Sources of polarized neutrons

International Nuclear Information System (INIS)

Walter, L.

1983-01-01

Various sources of polarized neutrons are reviewed. Monoenergetic source produced with unpolarized or polarized beams, white sources of polarized neutrons, production by transmissions through polarized hydrogen targets and polarized thermal neutronsare discussed, with appropriate applications included. (U.K.)

PolarHub: A Global Hub for Polar Data Discovery

Science.gov (United States)

Li, W.

2014-12-01

This paper reports the outcome of a NSF project in developing a large-scale web crawler PolarHub to discover automatically the distributed polar dataset in the format of OGC web services (OWS) in the cyberspace. PolarHub is a machine robot; its goal is to visit as many webpages as possible to find those containing information about polar OWS, extract this information and store it into the backend data repository. This is a very challenging task given huge data volume of webpages on the Web. Three unique features was introduced in PolarHub to make it distinctive from earlier crawler solutions: (1) a multi-task, multi-user, multi-thread support to the crawling tasks; (2) an extensive use of thread pool and Data Access Object (DAO) design patterns to separate persistent data storage and business logic to achieve high extendibility of the crawler tool; (3) a pattern-matching based customizable crawling algorithm to support discovery of multi-type geospatial web services; and (4) a universal and portable client-server communication mechanism combining a server-push and client pull strategies for enhanced asynchronous processing. A series of experiments were conducted to identify the impact of crawling parameters to the overall system performance. The geographical distribution pattern of all PolarHub identified services is also demonstrated. We expect this work to make a major contribution to the field of geospatial information retrieval and geospatial interoperability, to bridge the gap between data provider and data consumer, and to accelerate polar science by enhancing the accessibility and reusability of adequate polar data.

Polarization extinction ratio of the polarization crosstalk caused by point pressure force in the polarization-maintaining fiber

Science.gov (United States)

Mukhtubayev, Azamat B.; Aksarin, Stanislav M.; Strigalev, Vladimir E.

2017-11-01

A study of the orthogonal polarization modes crosstalk changes in the point of different mechanical actions (pressure force) in the polarization-maintaining fiber with straining elliptical cladding is presented. It was found that by increasing of the pressure force the polarization extinction ratio increases nonlinearly. Also revealed the dependence of the extinction coefficient and the angle between vector of the mechanical action and polarization axes of the test fiber, which leads to change the extinction coefficient variable from -57 dB to -25 dB under the pressure force of 0.7 N. Also it was found that the cross angle of the fiber axes doesn't influence on the extinction ratio value of the mechanical induced polarization crosstalk.

Polarized secondary radioactive beams

International Nuclear Information System (INIS)

Zaika, N.I.

1992-01-01

Three methods of polarized radioactive nuclei beam production: a) a method nuclear interaction of the non-polarized or polarized charged projectiles with target nuclei; b) a method of polarization of stopped reaction radioactive products in a special polarized ion source with than following acceleration; c) a polarization of radioactive nuclei circulating in a storage ring are considered. Possible life times of the radioactive ions for these methods are determined. General schemes of the polarization method realizations and depolarization problems are discussed

Actividad biológica e inmunológica de las isoformas de carga de la hormona luteinizante bovina

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Álvaro Ortega

2016-01-01

Full Text Available La hormona luteinizante (LH sufre modificaciones postraduccionales que dan origen a isoformas de carga. El estudio determinó la actividad biológica (B e inmunológica (I de distintas isoformas de LH bovina. Las isoformas se aislaron mediante el cromatoenfoque a partir del extracto glicoprotéico obtenido de lóbulos anteriores de hipófisis de bovino. La actividad biológica se evaluó en un bioensayo in vitro midiendo la producción de AMPc. La actividad inmunológica se midió con un radioinmunoensayo (RIA específico para LH. El USDA-bLH-B5 se utilizó como referencia. Las isoformas se agruparon tomando como referencia el rango de pH de elución, en básicas (A, pH, 10.75-9.75; B, pH, 9.58-8.41, neutras (C, pH, 7.98-6.89 y ácidas (D, pH, 6.88-5.41; E, pH, 5.36-3.46. El peso molecular del heterodímero de cada isoforma y del estándar fue similar, estimado en 36.5 kDa. La actividad inmunológica y biológica se comportó de forma dosis-dependiente. Con respecto al estándar, se requirió una mayor concentración de proteína de cada isoforma para obtener el IC50 en la curva de inhibición. En el bioensayo, el valor EC50 para la producción de AMPc fue significativamente diferente entre isoformas; la isoforma neutra mostró un EC50 inferior lo que se interpretó como la proteína más bioactiva, en contraste, la isoforma ácida, mostró un valor de EC50 superior y resultó ser la menos bioactiva; la básica tuvo un comportamiento intermedio (P<0.05. En conclusión, los resultados sugieren un efecto diferenciado de las isoformas de carga, sobre la producción cuantitativa de AMPc por unidad de LH inmunoreactiva.

KRS : A cut away from release in exosomes

NARCIS (Netherlands)

Rabouille, Catherine

2017-01-01

Cancer cells often trigger an inflammatory process, which in some cases may be driven by the presence of lysyl-tRNA synthetase (KRS) in the medium. Kim et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201605118) now demonstrate that cleavage of the KRS by caspase-8 inside cells triggers its

Scattering of polarized electrons from polarized targets: Coincidence reactions and prescriptions for polarized half-off-shell single-nucleon cross sections

International Nuclear Information System (INIS)

Caballero, J.A.; Massachusetts Inst. of Tech., Cambridge, MA; Donnelly, T.W.; Massachusetts Inst. of Tech., Cambridge, MA; Poulis, G.I.; Massachusetts Inst. of Tech., Cambridge, MA

1993-01-01

Coincidence reactions of the type vector A( vector e, e'N)B involving the scattering of polarized electrons from polarized targets are discussed within the context of the plane-wave impulse approximation. Prescriptions are developed for polarized half-off single-nucleon cross sections; the different prescriptions are compared for typical quasi-free kinematics. Illustrative results are presented for coincidence polarized electron scattering from typical polarized nuclei. (orig.)

Factores de riesgo para el desarrollo psicomotor en lactantes nacidos en óptimas condiciones biológicas

OpenAIRE

Isidora de Andraca; Paulina Pino; Alicia de La Parra; Francisca Rivera; Marcela Castillo

1998-01-01

OBJECTIVO: Evaluar el efecto de factores de riesgo para el desarrollo infantil en niños, de nivel socioeconómico bajo, nacidos en óptimas condiciones biológicas pero expuestos a condiciones sociales adversas. METODOLOGÍA: Lactantes de ambos sexos em número de 788, fueron exhaustivamente estudiados en términos de: alimentación, crecimiento, ambiente físico y psicosocial. Se controlaron prospectivamente hasta los 12 meses de edad, momento en que se evaluó el desarrollo mental (MDI) y motor (PDI...

Actividad contra Leishmania sp. (Kinetoplastida: Trypanosomatidae) de plantas en una Reserva Biológica de Costa Rica

OpenAIRE

Misael Chinchilla-Carmona; Idalia Valerio-Campos; Ronald Sánchez-Porras; Vanessa Bagnarello-Madrigal; Laura Martínez-Esquivel; Antonieta González-Paniagua; Javier Alpizar-Cordero; Maribel Cordero-Villalobos; Daniela Rodríguez-Chaves

2014-01-01

La leishmaniosis es una enfermedad muy importante para el ser humano pero su tratamiento es bastante difícil. Por esta razón muchos investigadores han venido buscando plantas que contengan componentes químicos activos contra esta parasitosis. En Costa Rica no se tienen estudios al respecto y por eso el objetivo de este estudio fue la búsqueda de componentes activos contra Leishmania sp. en plantas de Costa Rica; 67 especies de la Reserva Biológica Alberto Manuel Brenes (REBAMB) fueron selecci...

Ortho-Babinet polarization-interrogating filter: an interferometric approach to polarization measurement.

Science.gov (United States)

Van Delden, Jay S

2003-07-15

A novel, interferometric, polarization-interrogating filter assembly and method for the simultaneous measurement of all four Stokes parameters across a partially polarized irradiance image in a no-moving-parts, instantaneous, highly sensitive manner is described. In the reported embodiment of the filter, two spatially varying linear retarders and a linear polarizer comprise an ortho-Babinet, polarization-interrogating (OBPI) filter. The OBPI filter uniquely encodes the incident ensemble of electromagnetic wave fronts comprising a partially polarized irradiance image in a controlled, deterministic, spatially varying manner to map the complete state of polarization across the image to local variations in a superposed interference pattern. Experimental interferograms are reported along with a numerical simulation of the method.

Coronal Polarization of Pseudostreamers and the Solar Polar Field Reversal

Science.gov (United States)

Rachmeler, L. A.; Guennou, C.; Seaton, D. B.; Gibson, S. E.; Auchere, F.

2016-01-01

The reversal of the solar polar magnetic field is notoriously hard to pin down due to the extreme viewing angle of the pole. In Cycle 24, the southern polar field reversal can be pinpointed with high accuracy due to a large-scale pseudostreamer that formed over the pole and persisted for approximately a year. We tracked the size and shape of this structure with multiple observations and analysis techniques including PROBA2/SWAP EUV images, AIA EUV images, CoMP polarization data, and 3D tomographic reconstructions. We find that the heliospheric field reversed polarity in February 2014, whereas in the photosphere, the last vestiges of the previous polar field polarity remained until March 2015. We present here the evolution of the structure and describe its identification in the Fe XII 1074nm coronal emission line, sensitive to the Hanle effect in the corona.

Color sensitive silicon photomultiplers with micro-cell level encoding for DOI PET detectors

Science.gov (United States)

Shimazoe, Kenji; Koyama, Akihiro; Takahashi, Hiroyuki; Ganka, Thomas; Iskra, Peter; Marquez Seco, Alicia; Schneider, Florian; Wiest, Florian

2017-11-01

There have been many studies on Depth Of Interaction (DOI) identification for high resolution Positron Emission Tomography (PET) systems, including those on phoswich detectors, double-sided readout, light sharing methods, and wavelength discrimination. The wavelength discrimination method utilizes the difference in wavelength of stacked scintillators and requires a color sensitive photodetector. Here, a new silicon photomultiplier (SiPM) coupled to a color filter (colorSiPM) was designed and fabricated for DOI detection. The fabricated colorSiPM has two anode readouts that are sensitive to blue and green color. The colorSiPM's response and DOI identification capability for stacked GAGG and LYSO crystals are characterized. The fabricated colorSiPM is sensitive enough to detect a peak of 662 keV from a 137 Cs source.

Mejora de los indicadores biológicos de exposición al mercurio en trabajadores de una refinería de oro

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Augusto V. Ramírez

2011-07-01

Full Text Available Introducción: La exposición al mercurio asociada a malas prácticas de higiene laboral favorece el desarrollo de la intoxicación ocupacional denominada mercurialismo. Para verificar el impacto que la mejoría de los niveles ambientales de mercurio tendría en trabajadores de la refinería en una empresa aurífera peruana, se elaboró un programa de reingeniería para el control de la exposición que abarca aspectos de salud e higiene laboral y participación activa de la jefatura operativa. Objetivos: Estudiar en trabajadores de una refinería aurífera las variaciones de indicadores de exposición a mercurio al mejorar la calidad del ambiental laboral. Diseño: Estudio prospectivo y descriptivo. Lugar de estudio: Servicio de Salud Ocupacional de una empresa minera aurífera en el Perú. Participantes: Trabajadores de la refinería de oro. Intervenciones: Se modificó la metodología del examen médico y de la evaluación del ambiente laboral de 100 trabajadores de la refinería de oro, durante el periodo 2003-2007, además de mejorar las condiciones de trabajo. Luego, se cuantificó semestralmente los límites ambientales del tóxico y los indicadores de exposición. Se analizó estadísticamente la variación de los valores medios de los indicadores biológicos respecto a la variación del tóxico en el ambiente de trabajo. Principales medidas de resultados: Mejora de los indicadores ambientales y biológicos. Resultados: Los valores medios de los indicadores ambientales mejoraron cada año, al igual que los indicadores biológicos del universo estudiado. El mercurio ambiental en 2 003 fue 6,3 mg/m3 y, en 2 007, 0,03, valor de p < 0,001. El indicador mercurio urinario en 2003 fue 11,9 ug/L y, en 2007, 2,3 con p < 0,01. Conclusiones: En el grupo estudiado, la disminución del tóxico en el ambiente de labor determinó la mejora significativa de los indicadores biológicos de exposición al mercurio en el trabajador.

Experiments with Fermilab polarized proton and polarized antiproton beams

International Nuclear Information System (INIS)

Yokosawa, A.

1990-01-01

We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the π degree production at high p perpendicular and in the Λ (Σ degree), π ± , π degree production at large x F , and Δσ L (pp, bar pp) measurements. 18 refs

A comparison of photograph-interpreted and IfSAR-derived maps of polar bear denning habitat for the 1002 Area of the Arctic National Wildlife Refuge, Alaska

Science.gov (United States)

Durner, George M.; Atwood, Todd C.

2018-05-11

Polar bears (Ursus maritimus) in Alaska use the Arctic National Wildlife Refuge (ANWR) for maternal denning. Pregnant bears den in snow banks for more than 3 months in winter during which they give birth to and nurture young. Denning is one of the most vulnerable times in polar bear life history as the family group cannot simply walk away from a disturbance without jeopardizing survival of newly born cubs. The ANWR includes the “1002 Area”, a region recently opened for oil and gas exploration by the U.S. Department of the Interior (DOI). As a part of its mission, the DOI “… protects and manages the Nation's natural resources …” and is therefore responsible for conserving polar bears and encouraging development of energy potential. Because future industrial activities could overlap habitats used by denning polar bears, identifying these habitats can inform the decisions of resource managers tasked to develop resources and protect polar bears. To help inform these efforts, we qualitatively compared the distribution of denning habitat identified by two different methods: previously published habitat from manual interpretation of aerial photographs, and habitat derived by computer interrogation of interferometric synthetic aperture radar (IfSAR) digital terrain models (DTM). Because photograph-interpreted methods depicted denning habitat as a line and IfSAR-derived methods depicted habitat as a polygon, we assessed agreement between the two methods with distance measurements. We found that 77.5 percent of IfSAR-derived denning habitat (79.6 km2 ; 1.2 percent of the 6,837.0 km2 1002 Area) was within 600 m of photograph-interpreted habitat (3,026.9 km), including 53.9 percent within 200 m. This distribution differed from that of randomly distributed points, as only 49.4 percent of these occurred within 600 m of photograph-interpreted habitat, including 18.3 percent within 200 m. Both methods appear to identify the major physiographic features that polar bears

Recent advance in polar seismology: Global impact of the International Polar Year

Science.gov (United States)

Kanao, Masaki; Zhao, Dapeng; Wiens, Douglas A.; Stutzmann, Éléonore

2015-03-01

The most exciting initiative for the recent polar studies was the International Polar Year (IPY) in 2007-2008. The IPY has witnessed a growing community of seismologists who have made considerable efforts to acquire high-quality data in polar regions. It also provided an excellent opportunity to make significant advances in seismic instrumentation of the polar regions to achieve scientific targets involving global issues. Taking these aspects into account, we organize and publish a special issue in Polar Science on the recent advance in polar seismology and cryoseismology as fruitful achievements of the IPY.

Análisis de percepción de riesgos laborales de tipo biológico con la utilización de un sistema informático especializado

Directory of Open Access Journals (Sweden)

Ana Teresa Carbonell Siam

Full Text Available Introducción: la no disponibilidad e insuficiente flexibilidad de las herramientas de estudio de percepción de riesgo es limitante para alcanzar su generalización en diferentes ámbitos. Objetivo: diseñar un sistema informático para evaluación de percepción de riesgo flexible y demostrar su capacidad a través de aplicaciones a varios casos de estudio. Métodos: a partir del método de evaluación de percepción de riesgo ocupacional (EPRO, se elaboró el algoritmo base del código RISKPERCEP. Resultados: el método EPRO, informatizado a través de RISKPERCEP, se aplicó a escenarios diversos con peligro biológico asociado, como una empresa de producción de productos biológicos, un banco de sangre y las labores de las brigadas de vigilancia y lucha antivectorial. Se obtuvo en general, un perfil de subestimación de los peligros entre el personal ocupacionalmente expuesto. Conclusiones: la herramienta computarizada identificada como RISKPERCEP facilita la evaluación de percepción de riesgo, de manera que flexibiliza el análisis y permite su extensión a diferentes escenarios con riesgo biológico.

Study of excess carrier dynamics in polar, semi-polar, and non-polar (In,Ga)N epilayers and QWs

Energy Technology Data Exchange (ETDEWEB)

Aleksiejunas, R. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Lubys, L.; Jarasiunas, K. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Vengris, M. [Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Wernicke, T.; Hoffmann, V.; Netzel, C.; Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Kneissl, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Institute of Solid State Physics, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)

2011-07-15

We studied carrier recombination and diffusion in GaN/sapphire templates, (In,Ga)N layers, and (In,Ga)N quantum well structures oriented along the polar [0001], semi-polar [11-22], and non-polar [11-20] orientations by means of light induced transient grating, differential transmission, and photoluminescence optical techniques. We show that the lifetime of excess carriers drops by orders of magnitude when changing the orientation from polar to non-polar, both in GaN templates and (In,Ga)N layers. We attribute the shorter lifetime to carrier trapping by extended structural defects that are more abundant in non-polar grown samples. In addition, we observe pronounced carrier localization effects in the semi- and non-polar layers. We show that thick (In,Ga)N layers inherit the properties of the GaN templates. However, the thin quantum well structures show a lower carrier trapping activity. So, a better electrical quality can be assumed as compared to the thick (In,Ga)N layers. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Determinação da segurança biológica do xampu de cetoconazol: teste de irritação ocular e avaliação do potencial de citotoxicidade in vitro Determination of the biological reactivity of ketoconazole in shampoo: draize eye test and cytotoxity test

Directory of Open Access Journals (Sweden)

Inara Staub

2007-06-01

Full Text Available Cetoconazol é um agente antifúngico, que pode ser incorporado em diferentes formas farmacêuticas, como, por exemplo, xampus e cremes. O objetivo do trabalho foi avaliar a segurança biológica in vivo (teste de irritação ocular e in vitro (teste de citotoxicidade do xampu de cetoconazol degradado sob ação da luz. Para tanto, a formulação foi exposta à radiação UV-C (254 nm e foram empregados dois métodos para a determinação quantitativa do cetoconazol: CLAE e ensaio microbiológico. Os resultados demonstraram alteração do cetoconazol em presença da luz - presença de picos secundários no cromatograma e diminuição da atividade antifúngica - entretanto, não demonstraram alteração na segurança biológica entre xampu de cetoconazol e xampu de cetoconazol contendo produtos de degradação.Ketoconazole is an antifungal agent and can be incorporated into several dosage forms, as an example it could be mentioned shampoos and creams. The aim of this work was to assess the biological reactivity in vivo (Draize eye test and in vitro (cytotoxity test of ketoconazole in shampoo degradeted under action of light. The formulation was exposed to UV-C (254 nm radiation and two methods were used for the quantitative determination of ketoconazole: HPLC and microbiological assay. The results showed alteration in ketoconazole in presence of light - secondary peaks in chromatogram and decrease in antifungal activity - however, no alteration on the biological reactivity between ketoconazole shampoo and ketoconazole shampoo containing degradation products was observed.

Polarized targets and beams

International Nuclear Information System (INIS)

Meyer, W.

1985-01-01

First the experimental situation of the single-pion photoproduction and the photodisintegration of the deuteron is briefly discussed. Then a description of the Bonn polarization facilities is given. The point of main effort is put on the polarized target which plays a vital role in the program. A facility for photon induced double polarization experiments at ELSA will be presented in section 4. Properties of a tensor polarized deuteron target are discussed in section 5. The development in the field of polarized targets, especially on new target materials, enables a new generation of polarized target experiments with (polarized) electrons. Some comments on the use of a polarized target in combination with electron beams will be discussed in section 6. Electron deuteron scattering from a tensor polarized deuteron target is considered and compared with other experimental possibilities. (orig./HSI)

New developments at INFN-LNS on TOF–DOI PET based on SiPM detectors

International Nuclear Information System (INIS)

Cosentino, L.; Cusanno, F.; De Leo, R.; Di Venti, G.; Finocchiaro, P.; Garibaldi, F.; Loddo, F.; Meddi, F.; Musico, P.; Pappalardo, A.; Perrino, R.; Ranieri, A.

2013-01-01

The development of an endorectal PET Time Of Flight (TOF) probe prototype compatible with MRI, is going to be carried out within the INFN project TOPEM. Time resolution and depth of interaction (DOI) will allow to significantly improve the image quality, by rejecting those events coming from the surrounding tissues and correcting the parallax error. The activity described in this paper is focused on the characterization of the single pixel detector of the probe, consisting of a LYSO finger scintillator read out at both ends by means of a pair of Silicon Photomultipliers (SiPM). Energy, timing and DOI resolutions have been measured with a proper surface treatment and wrapping, finding very competitive results for DOI and timing

Disponibilidade biológica do fósforo de diferentes fontes para eqüinos em crescimento

Directory of Open Access Journals (Sweden)

FURTADO CARLOS EDUARDO

2000-01-01

Full Text Available Objetivou-se neste estudo, determinar a disponibilidade biológica do P de diferentes fontes, para eqüinos em fase de crescimento. Utilizaram-se dezesseis eqüinos machos em fase de crescimento, submetidos à aplicação de quatro fontes fosfatadas -- fosfato de rocha de Tapira (TAP, fosfato de rocha de Patos de Minas (PAT, fosfato bicálcico (BIC e farinha de osso (FOS --, adicionadas à dieta basal em quantidades suficientes para fornecer 22 g de P/animal/dia. No 16º dia, foram-lhes injetados 30 MBq de 32P/animal, e coletaram-se amostras de sangue, fezes e urina, durante sete dias. Foram determinadas as atividades específicas no plasma, fezes e urina e calculou-se a perda endógena fecal e a absorção real de P. Os valores obtidos quanto ao P consumido, P excretado, P no plasma e P retido não apresentaram diferenças estatísticas (P>0,05. Os valores de absorção real do P do TAP, PAT, BIC e da FOS foram, respectivamente, 25,23%, 33,97%, 31,71% e 29,36%. Não houve diferenças estatísticas (P>0,05 entre as fontes estudadas. Em relação ao BIC, as rochas fosfáticas apresentaram altos valores de disponibilidade biológica.

Estudo fitoquímico e ensaios biológicos de Davilla Kunthii A. St. Hil (Dilleniaceae)

OpenAIRE

Leandro da Silva Nascimento

2014-01-01

O uso de plantas ou extratos de plantas para propósitos medicinais tem sido realizado a milhares de anos. O estudo químico e biológico de plantas constitui numa estratégia alternativa na procura de novos agentes terapêuticos para a identificação de compostos bioativos. A espécie Davilla kunthii A. St. Hil, pertencente à família Dilleniaceae, é conhecida popularmente como cipódefogo e podem ser encontradas em regiões de savana. Este trabalho teve como objetivo realizar o estudo fitoquímico e e...

Reduction of coating induced polarization aberrations by controlling the polarization state variation

International Nuclear Information System (INIS)

Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

2011-01-01

The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

Energy Technology Data Exchange (ETDEWEB)

Fischer, W.; Bazilevsky, A.

2011-08-18

The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. {bar P}), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g.

).

Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

International Nuclear Information System (INIS)

Fischer, W.; Bazilevsky, A.

2011-01-01

The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. (bar P)), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g. ).

Japan Link Center (JaLC): link management and DOI assignment for Japanese electronic scholarly contents

Science.gov (United States)

Kato, Takafumi; Tsuchiya, Eri; Kubota, Soichi; Miyagawa, Yoshiyuki

JST, cooperated with several national institutes, is currently developing “Japan Link Center”, which manages Japanese electronic scholarly contents (journal articles, books, dissertations etc.) in an integrated fashion using Digital Object Identifier (DOI). Japan Link Center will manage metadata and whereabouts information of the contents in the digital environment and provide domestic and international linking information, cite/cited information to activate dissemination of S&T information, furthermore, to strengthen transmission of S&T information from Japan. Japan Link Center is expected to be appointed as the 9th DOI registration agency (RA) in the world by the International DOI Foundation (IDF) this spring.

Analysis of accidents with organic material in health workers Análisis de los accidentes con material biológico en trabajadores de la salud Análise dos acidentes com material biológico em trabalhadores da saúde

Directory of Open Access Journals (Sweden)

Mariana Vieira

2011-04-01

Full Text Available This retrospective and descriptive study with a quantitative design aimed to evaluate occupational accidents with exposure to biological material, as well as the profile of workers, based on reporting forms sent to the Regional Reference Center of Occupational Health in Florianópolis/SC. Data collection was carried out through a survey of 118 reporting forms in 2007. Data were analyzed electronically. The occurrence of accidents was predominantly among nursing technicians, women and the mean age was 34.5 years. 73% of accidents involved percutaneous exposure, 78% had blood and fluid with blood, 44.91% resulted from invasive procedures. It was concluded that strategies to prevent the occurrence of accidents with biological material should include joint activities between workers and service management and should be directed at improving work conditions and organization.Estudio retrospectivo descriptivo con abordaje cuantitativo, cuyo objetivo fue conocer los accidentes de trabajo con exposición a material biológico y el perfil de los trabajadores, a partir de las fichas de notificación del Centro de Referencia Regional en Salud del Trabajador de la Macro Región de Florianópolis. La recolección de datos fue realizada por el levantamiento de las 118 fichas de notificación de 2007. Los datos fueron analizados electrónicamente. Los accidentes ocurrieron predominantemente entre los técnicos de enfermería del sexo femenino y edad promedio de 34,5 años; 73% de los accidentes envolvieron exposición percutánea; 78% tuvieron contacto con sangre y/o fluidos con sangre; 44,91% provinieron de procedimientos invasores. Se concluye que las estrategias de prevención a la ocurrencia de los accidentes de trabajo con material biológico deben incluir acciones conjuntas, entre trabajadores y gerencia de los servicios, debiendo estar dirigidas a mejorar las condiciones y organización del trabajo.Este é um estudo retrospectivo descritivo, com

Nuclear polarization and neutrons

International Nuclear Information System (INIS)

Glaettli, H.

1985-01-01

Different possibilities for the use of polarized nuclei in thermal neutron scattering on condensed matter are reviewed. Highly polarized nuclei are the starting point for studying dipolar magnetic order. Systematic measurement of spin-dependent scattering lengths is possible on samples with polarized nuclei. Highly polarized hydrogen should help to unravel complicated structures in chemistry and biology. The use of polarized proton targets as an energy-independent neutron polarizer in the thermal and epithermal region should be considered afresh. (author)

NUCLEON POLARIZATION IN 3-BODY MODELS OF POLARIZED LI-6

NARCIS (Netherlands)

SCHELLINGERHOUT, NW; KOK, LP; COON, SA; ADAM, RM

1993-01-01

Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

Correction to “Advancing the Conversation: Next Steps for Lesbian, Gay, Bisexual, Trans, and Queer (LGBTQ Health Sciences Librarianship” on 105(4 October, page 325. DOI: http://dx.doi.org/10.5195/jmla.2017.206

Directory of Open Access Journals (Sweden)

Katherine G. Akers

2018-01-01

Full Text Available Corrects author name in reference #11 of “Advancing the Conversation: Next Steps For Lesbian, Gay, Bisexual, Trans, and Queer (LGBTQ Health Sciences Librarianship” on 105(4 October, page 325. DOI: http://dx.doi.org/10.5195/jmla.2017.206.

Superconducting polarizing magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for the JINR (Dubna) movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T in the centre with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet contains a main solenoidal winding 558 mm long and 206/144 mm in diameters, and compensating and correcting winding placed at its ends. The windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat. The diameter of the 'warm' aperture of the magnet cryostat is 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements, using a NMR-magnetometer are given. A similar magnet constructed at DAPNIA, CEA/Saclay (France), represented a model for the present development. The MPT array is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the synchrophasotron of the Laboratory of High Energies (LHE), JINR (Dubna)

Efeitos biológicos das radiações ionizantes: acidente radiológico de Goiânia

OpenAIRE

Okuno, Emico

2013-01-01

Neste artigo apresentamos as bases da Física das radiações, as fontes naturais e artificiais, os efeitos biológicos, a proteção radiológica. Examinamos também a sequência de eventos que resultou no acidente de Goiânia com uma fonte de césio-137 de um equipamento de radioterapia abandonado e suas terríveis consequências.This article presents the fundaments of radiation physics, the natural and artificial sources, biological effects, radiation protection. We also examine the sequence of events ...

Sintesis y evaluación biológica de nuevos derivados de tipo imidazolina y etanolamina fluorados

OpenAIRE

Flores Penalba, Sonia

2011-01-01

Una de las principales áreas de interés de la química orgánica es la búsqueda de nuevos compuestos con actividad biológica. En este sentido cabe destacar el especial interés que despiertan los compuestos nitrogenados debido a que constituyen una de las familias más numerosas entre las biomoléculas y que están implicados en múltiples procesos a nivel metabólico y estructural. Un ejemplo representativo los constituyen los compuestos de tipo etanolamina, ampliamente estudiados por sus variad...

El enemigo olvidado: la ricina y su amenaza como arma biológica a los Estados Unidos

OpenAIRE

Martínez Pantoja, Yadira Ixchel

2005-01-01

El riesgo latente de un ataque terrorista con armas nucleares fue el centro de atención de todas las agencias de seguridad de los Estados Unidos y las naciones aliadas durante la Guerra Fría. Sin embargo, los avances en la genética y la biotecnología han puesto en manos terroristas nuevas armas para vulnerar la seguridad nacional estadounidense: los agentes biológicos. Además, los ataques del 11 de Septiembre modificaron el concepto de seguridad nacional forzando a los depar...

Análise conjunta de atributos físicos e biológicos do solo sob sistema de integração lavoura-pecuária

Directory of Open Access Journals (Sweden)

Rogério Ferreira da Silva

2011-10-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos do sistema integração lavoura-pecuária (ILP sobre os atributos morfológicos, físicos e biológicos do solo. O experimento foi realizado em Dourados, MS, em Latossolo Vermelho distroférrico típico. Foram avaliados os seguintes sistemas: monocultura com sistema convencional de preparo do solo, ILP com sistema plantio direto, pastagem contínua de Urochloa decumbens (Syn. Brachiaria decumbens e vegetação nativa. Em cada sistema, foi aberta uma trincheira com o intuito de detectar as modificações morfológicas provocadas pelos diferentes manejos com uso do método do perfil cultural. Os macroinvertebrados do solo foram avaliados conforme o método "Tropical Soil Biology and Fertility". Utilizaram-se, ainda, amostras de solo indeformadas para avaliação dos atributos físicos do solo (densidade do solo, porosidade total, macro e microporosidade. Entre os sistemas produtivos, a melhor estrutura do solo foi verificada no sistema ILP, nas camadas de 0-0,1 e 0,1-0,2 m. Os sistemas sob ILP e em pastagem cultivada continuamente favoreceram um ambiente edáfico biologicamente mais ativo em comparação aos outros sistemas cultivados. A visualização conjunta dos atributos do solo mostrou que a integração lavoura-pecuária é uma estratégia para desenvolver sistemas de produção sustentáveis e que o período de dois anos de manejo é adequado para a rotação lavoura-pecuária.

Cutting edge science: Laser surgery illuminates viscoelasticity of merotelic kinetochores.

Science.gov (United States)

Cabello, Simon; Gachet, Yannick; Tournier, Sylvie

2016-03-28

Increasing evidence in eukaryotic cells suggests that mechanical forces are essential for building a robust mitotic apparatus and correcting inappropriate chromosome attachments. In this issue, Cojoc et al. (2016. J. Cell Biol., http://dx.doi.org/10.1083/jcb.201506011) use laser microsurgery in vivo to measure and study the viscoelastic properties of kinetochores. © 2016 Cabello.

The Tumor Suppressor Actions of the Vitamin D Receptor in Skin

Science.gov (United States)

2013-08-01

beta-catenin signaling. J Cell Biol. 2001; 154:369–387. [PubMed: 11470825] 76. Shah S, Hecht A, Pestell R, Byers SW. Trans-repression of beta-catenin...pMID:15668160; http://dx.doi.org/10.1016/j.cub.2004.12.058. 122. Shah S, hecht a, pestell r, Byers SW. trans‑repression of beta‑catenin activity by

Atendimento e seguimento clínico especializado de profissionais de enfermagem acidentados com material biológico Atención y seguimiento clínico especializado de profesionales de enfermería accidentados con material biológico Care and specialized clinical follow-up of nursing professionals who have been victims of accidents with biological material

Directory of Open Access Journals (Sweden)

Flaviana Regina Pimenta

2013-02-01

Full Text Available O presente trabalho trata-se de estudo de corte transversal, com objetivo de avaliar a conduta dos profissionais de enfermagem vítimas de acidentes com material biológico, do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, no estado de São Paulo, referente ao atendimento e ao seguimento clínico especializado. A população foi composta por 1.215 profissionais de enfermagem, entrevistados entre os anos de 2010 e 2011, dos quais 636 (52,3% sofreram acidentes com material biológico e 182 (28,6% não procuraram atendimento no serviço especializado. O motivo mais frequentemente relatado foi atribuir pouco risco ao acidente. Assim, acredita-se que os motivos alegados pelos profissionais para não procurarem o atendimento, para não completarem a terapêutica e nem o seguimento clínico podem contribuir para a proposição de estratégias capazes de aumentar a adesão às medidas profiláticas após exposição ocupacional a material biológico.Estudio de corte transversal, apuntando a evaluar la conducta de profesionales de enfermería víctimas de accidentes con material biológico, del Hospital de Clínicas de la Facultad de Medicina de Ribeirão Preto, Universidad de São Paulo, en el estado de São Paulo; referente a la atención y seguimiento clínico especializado. La población estuvo integrada por 1215 profesionales de enfermería, entrevistados entre 2010 y 2011, de los cuales 636 (52,3% sufrieron accidentes con material biológico y 182 (28,6% no solicitaron atención en el servicio especializado. El motivo relatado con mayor frecuencia fue atribuir escaso riesgo al accidente. De tal modo, se cree que los motivos alegados por los profesionales para no solicitar atención, para no completar la terapéutica ni el seguimiento clínico pueden ser facilitar la propuesta de estrategias capaces de aumentar su adhesión a las medidas profilácticas luego de exposición laboral a materiales biol

CMB polarization at large angular scales: Data analysis of the POLAR experiment

International Nuclear Information System (INIS)

O'Dell, Christopher W.; Keating, Brian G.; Oliveira-Costa, Angelica de; Tegmark, Max; Timbie, Peter T.

2003-01-01

The coming flood of cosmic microwave background (CMB) polarization experiments, spurred by the recent detection of CMB polarization by the DASI and WMAP instruments, will be confronted by many new analysis tasks specific to polarization. For the analysis of CMB polarization data sets, the devil is truly in the details. With this in mind, we present details of the data analysis for the POLAR experiment, which recently led to the tightest upper limits on the polarization of the cosmic microwave background radiation at large angular scales. We discuss the data selection process, map-making algorithms, offset removal, and likelihood analysis which were used to find upper limits on the polarization. Stated using the modern convention for reporting CMB Stokes parameters, these limits are 5.0 μK on both E- and B-type polarization at 95% confidence. Finally, we discuss simulations used to test our analysis techniques and to probe the fundamental limitations of the experiment

Energy spectra analysis of the four-layer DOI detector for the brain PET scanner: jPET-D4

International Nuclear Information System (INIS)

Yoshida, Eiji; Kitamura, Keishi; Tsuda, Tomoaki; Shibuya, Kengo; Yamaya, Taiga; Inadama, Naoko; Hasegawa, Tomoyuki; Murayama, Hideo

2006-01-01

A depth of interaction (DOI) detector is being developed for the brain PET scanner, jPET-D4. We introduce a light output correction procedure to compensate for variations among the crystal elements in the DOI detector. Under uniform irradiation with 511 keV gamma rays, we estimate the light output of each crystal element by identifying each crystal element, and generate a look-up table (LUT) for light output correction. We evaluate the energy resolution of all crystal elements. The energy resolution of 16% is achieved after light output correction for all crystal elements. The DOI detector can correct light output variations that are related to the DOI. We analyze the crystal position dependence of the energy spectra due to inter-crystal scattering among the multiple crystal elements in the DOI detector. It is highly possible that gamma rays interacting with central crystal elements in the crystal array are absorbed by surrounding crystal elements and the Compton part of the energy spectrum is decreased. Inter-crystal scattering has less impact on the energy resolution of the DOI detector

Few-body experiments with polarized beams and polarized targets

International Nuclear Information System (INIS)

Simmons, J.E.

1983-01-01

A survey is presented concerning recent polarization experiments in the elastic p-d, p- 3 He, and p- 4 He systems. Mention is made of selected neutron experiments. The nominal energy range is 10 to 1000 MeV. Recent results and interpretations of the p-d system near 10 MeV are discussed. New experiments on the energy dependence of back angle p-d tensor polarization are discussed with respect to resolution of discrepancies and difficulty of theoretical interpretation. Progress is noted concerning multiple scattering interpretation of forward p-d deuteron polarization. Some new results are presented concerning the p- 3 He system and higher energy p- 4 He polarization experiments. 52 references

Avaliação da condição actual de três psicinas biológicas localizadas nos concelhos de Vieira do Minho e Póvoa de Lanhoso

OpenAIRE

Geraldes, Ana Maria

2007-01-01

As piscinas biológicas são pequenos lagos construídos onde são recriadas as condições ecológicas que ocorrem em ecossistemas lacustres naturais. Ao contrário das piscinas convencionais a depuração da água é realizada por filtros biológicos de macrófitas e nenhum produto químico é adicionado. À semelhança dos lagos naturais, para além das plantas aquáticas, ocorrem também organismos do fito e do zooplâncton, macro-invertebrados e alguns vertebrados, como é o caso dos anfíbios...

Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

International Nuclear Information System (INIS)

Makita, K.; Meng, C.

1987-01-01

On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

Degree of polarization and source counts of faint radio sources from Stacking Polarized intensity

International Nuclear Information System (INIS)

Stil, J. M.; George, S. J.; Keller, B. W.; Taylor, A. R.

2014-01-01

We present stacking polarized intensity as a means to study the polarization of sources that are too faint to be detected individually in surveys of polarized radio sources. Stacking offers not only high sensitivity to the median signal of a class of radio sources, but also avoids a detection threshold in polarized intensity, and therefore an arbitrary exclusion of sources with a low percentage of polarization. Correction for polarization bias is done through a Monte Carlo analysis and tested on a simulated survey. We show that the nonlinear relation between the real polarized signal and the detected signal requires knowledge of the shape of the distribution of fractional polarization, which we constrain using the ratio of the upper quartile to the lower quartile of the distribution of stacked polarized intensities. Stacking polarized intensity for NRAO VLA Sky Survey (NVSS) sources down to the detection limit in Stokes I, we find a gradual increase in median fractional polarization that is consistent with a trend that was noticed before for bright NVSS sources, but is much more gradual than found by previous deep surveys of radio polarization. Consequently, the polarized radio source counts derived from our stacking experiment predict fewer polarized radio sources for future surveys with the Square Kilometre Array and its pathfinders.

Hidrocefalia multiloculada: relato de dois casos

Directory of Open Access Journals (Sweden)

Marilisa M. Guerreiro

1988-09-01

Full Text Available Hidrocefalia multiloculada é conceituada como quadro clínico-patológico que consiste de ventrículos aumentados e loculados e de cavidades porencefálicas paraventriculares. Apresentamos dois casos de hidrocefalia multiloculada, um provavelmente conseqüente a processo infeccioso do sistema nervoso central e outro em decorrência de malformação congênita. Aspectos tomográficos compatíveis ao diagnóstico são ressaltados. A etiopatogenia, o tratamento e o prognóstico são discutidos em face da literatura compulsada.

Polarization developments

International Nuclear Information System (INIS)

Prescott, C.Y.

1993-07-01

Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

Geographical Income Polarization

DEFF Research Database (Denmark)

Azhar, Hussain; Jonassen, Anders Bruun

inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live...

Perceiving polarization with the naked eye: characterization of human polarization sensitivity

Science.gov (United States)

Temple, Shelby E.; McGregor, Juliette E.; Miles, Camilla; Graham, Laura; Miller, Josie; Buck, Jordan; Scott-Samuel, Nicholas E.; Roberts, Nicholas W.

2015-01-01

Like many animals, humans are sensitive to the polarization of light. We can detect the angle of polarization using an entoptic phenomenon called Haidinger's brushes, which is mediated by dichroic carotenoids in the macula lutea. While previous studies have characterized the spectral sensitivity of Haidinger's brushes, other aspects remain unexplored. We developed a novel methodology for presenting gratings in polarization-only contrast at varying degrees of polarization in order to measure the lower limits of human polarized light detection. Participants were, on average, able to perform the task down to a threshold of 56%, with some able to go as low as 23%. This makes humans the most sensitive vertebrate tested to date. Additionally, we quantified a nonlinear relationship between presented and perceived polarization angle when an observer is presented with a rotatable polarized light field. This result confirms a previous theoretical prediction of how uniaxial corneal birefringence impacts the perception of Haidinger's brushes. The rotational dynamics of Haidinger's brushes were then used to calculate corneal retardance. We suggest that psychophysical experiments, based upon the perception of polarized light, are amenable to the production of affordable technologies for self-assessment and longitudinal monitoring of visual dysfunctions such as age-related macular degeneration. PMID:26136441

43 CFR 2.2 - What is DOI's policy regarding release of records under the FOIA?

Science.gov (United States)

2010-10-01

... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false What is DOI's policy regarding release of... RECORDS AND TESTIMONY; FREEDOM OF INFORMATION ACT General Information § 2.2 What is DOI's policy regarding... public consistent with the spirit of the FOIA and the Privacy Act. ...

Cronobiologia e inclusão educacional de pessoas cegas: do biológico ao social

Directory of Open Access Journals (Sweden)

Camila Fabiana Rossi Squarcini

2013-12-01

Full Text Available Estudos sobre inclusão educacional têm apontado alguns caminhos para garantir a inserção da pessoa com deficiência no espaço regular de ensino. Entretanto, pouco se tem falado a respeito das implicações do ritmo circadiano na inclusão da pessoa totalmente cega nesse espaço. Assim, o presente artigo teve como objetivo descrever como o ritmo circadiano pode influenciar na inclusão educacional do aluno com deficiência visual. A partir da revisão literária foram apresentadas as ideias fundamentais a respeito da cronobiologia, ciência que estuda a capacidade dos seres vivos em expressar de forma recorrente e periódica o seu comportamento e a sua fisiologia. Uma de suas expressões tem uma duração próxima há 24 horas, conhecido como ritmo circadiano. Esse ritmo é regido pelo relógio biológico que é controlado pela luz. Entretanto, na ausência da luz, caso de pessoas totalmente cegas, quem passa a reger os ritmos circadianos é apenas o relógio biológico. Nessa condição, conhecida como livrecurso, as pessoas totalmente cegas podem apresentar uma queda no desempenho acadêmico de tempos em tempos por causa da sonolência excessiva durante as horas de estudo, além de distúrbio no humor, no alerta e na atenção. Neste contexto, se faz necessário a divulgação desse conhecimento para que sejam reconhecidas as condições de déficit de atenção, irritabilidade, isolamento social e/ou sonolência excessiva durante o dia, oriundas do livre-curso afim de respeitar a individualidade dos alunos totalmente cegos e garantir o acesso à inclusão educacional em sua completude.

Measurement of the polarized neutron---polarized 3He total cross section

International Nuclear Information System (INIS)

Keith, C.D.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Huffman, P.R.; Roberson, N.R.; Tornow, W.; Wilburn, W.S.

1995-01-01

The first measurements of polarized neutron--polarized 3 He scattering in the few MeV energy region are reported. The total cross section difference Δσ T for transversely polarized target and beam has been measured for neutron energies between 1.9 and 7.5 MeV. Comparison is made to predictions of Δσ T using various descriptions of the 4 He continuum. A brute-force polarized target of solid 3 He has been developed for these measurements. The target is 4.3x10 22 atoms/cm 2 thick and is polarized to 38% at 7 Telsa and 12 mK. copyright 1995 American Institute of Physics

Scattering with polarized neutrons

International Nuclear Information System (INIS)

Schweizer, J.

2007-01-01

In the history of neutron scattering, it was shown very soon that the use of polarized neutron beams brings much more information than usual scattering with unpolarized neutrons. We shall develop here the different scattering methods that imply polarized neutrons: 1) polarized beams without polarization analysis, the flipping ratio method; 2) polarized beams with a uniaxial polarization analysis; 3) polarized beams with a spherical polarization analysis. For all these scattering methods, we shall give examples of the physical problems which can been solved by these methods, particularly in the field of magnetism: investigation of complex magnetic structures, investigation of spin or magnetization densities in metals, insulators and molecular compounds, separation of magnetic and nuclear scattering, investigation of magnetic properties of liquids and amorphous materials and even, for non magnetic material, separation between coherent and incoherent scattering. (author)

Dynamically polarized hydrogen target as a broadband, wavelength-independent thermal neutron spin polarizer

International Nuclear Information System (INIS)

Zhao Jinkui; Garamus, Vasil M.; Mueller, Wilhelm; Willumeit, Regine

2005-01-01

A hydrogen-rich sample with dynamically polarized hydrogen nuclei was tested as a wavelength-independent neutron transmission spin polarizer. The experiment used a modified setup of the dynamic nuclear polarization target station at the GKSS research center. The standard solvent sample at the GKSS DNP station was used. It is 2.8mm thick and consists of 43.4wt% water, 54.6wt% glycerol, and 2wt% of EHBA-Cr(v) complex. The wavelength of the incident neutrons for the transmission experiment was λ=8.1A with Δλ/λ=10%. The polarization of neutron beam after the target sample was analyzed with a supermirror analyzer. A neutron polarization of -52% was achieved at the hydrogen polarization of -69%. Further experiments will test the feasibility of other hydrogen-rich materials, such as methane, as the polarizer. A theoretical calculation shows that a polarized methane target would allow over 95% neutron polarizations with more than 30% transmission

String theory in polar coordinates and the vanishing of the one-loop Rindler entropy

Energy Technology Data Exchange (ETDEWEB)

Mertens, Thomas G. [Joseph Henry Laboratories, Princeton University,Princeton, NJ 08544 (United States); Verschelde, Henri [Ghent University, Department of Physics and Astronomy,Krijgslaan, 281-S9, 9000 Gent (Belgium); Zakharov, Valentin I. [ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation); Moscow Inst Phys & Technol,Dolgoprudny, Moscow Region, 141700 (Russian Federation); School of Biomedicine, Far Eastern Federal University,Sukhanova str 8, Vladivostok 690950 (Russian Federation)

2016-08-19

We analyze the string spectrum of flat space in polar coordinates, following the small curvature limit of the SL(2,ℝ)/U(1) cigar CFT. We first analyze the partition function of the cigar itself, making some clarifications of the structure of the spectrum that have escaped attention up to this point. The superstring spectrum (type 0 and type II) is shown to exhibit an involution symmetry, that survives the small curvature limit. We classify all marginal states in polar coordinates for type II superstrings, with emphasis on their links and their superconformal structure. This classification is confirmed by an explicit large τ{sub 2} analysis of the partition function. Next we compare three approaches towards the type II genus one entropy in Rindler space: using a sum-over-fields strategy, using a Melvin model approach as in http://dx.doi.org/10.1007/JHEP05(2015)106 and finally using a saddle point method on the cigar partition function. In each case we highlight possible obstructions and motivate that the correct procedures yield a vanishing result: S=0. We finally discuss how the QFT UV divergences of the fields in the spectrum disappear when computing the free energy and entropy using Euclidean techniques.

Possibility of determining gluon polarization via polarized top pairs in gamma-proton scattering

International Nuclear Information System (INIS)

Atag, S.; Billur, A.A.

2009-01-01

We study the possibility for directly measuring the polarized gluon distribution in the process γp→t-bar t. It is shown that polarization asymmetry of the final top quarks is proportional to the gluon polarization. With available energy and luminosity, the collision of a polarized proton beam and a Compton backscattered photon beam can create polarized top quarks which carry the spin information of the process. Energy dependence and angular distributions of the polarization asymmetry of the top pairs has been discussed including statistical uncertainty.

Material and device studies for the development of ultra-violet light emitting diodes (UV-LEDS) along polar, non-polar and semi-polar directions

Science.gov (United States)

Chandrasekaran, Ramya

Over the past few years, significant effort was dedicated to the development of ultraviolet light emitting diodes (UV-LEDs) for a variety of applications. Such applications include chemical and biological detection, water purification and solid-state lighting. III-Nitride LEDs based on multiple quantum wells (MQWs) grown along the conventional [0001] (polar) direction suffer from the quantum confined Stark effect (QCSE), due to the existence of strong electric fields that arise from spontaneous and piezoelectric polarization. Thus, there is strong motivation to develop MQW-based III-nitride LED structures grown along non-polar and semi-polar directions. The goal of this dissertation is to develop UV-LEDs along the [0001] polar and [11 2¯ 0] non-polar directions by the method of Molecular Beam Epitaxy (MBE). The polar and non-polar LEDs were grown on the C-plane and R-plane sapphire substrates respectively. This work is a combination of materials science studies related to the nucleation, growth and n- and p-type doping of III-nitride films on these two substrates, as well as device studies related to fabrication and characterization of UV-LEDs. It was observed that the crystallographic orientation of the III-nitride films grown on R-plane sapphire depends strongly on the kinetic conditions of growth of the Aluminum Nitride (AIN) buffer. Specifically, growth of the AIN buffer under group III-rich conditions leads to nitride films having the (11 2¯ 0) non polar planes parallel to the sapphire surface, while growth of the buffer under nitrogen rich conditions leads to nitride films with the (11 2¯ 6) semi-polar planes parallel to the sapphire surface. The electron concentration and mobility for the films grown along the polar, non-polar and semi-polar directions were investigated. P-type doping of Gallium Nitride (GaN) films grown on the nonpolar (11 2¯ 0) plane do not suffer from polarity inversion and thus the material was doped p-type with a hole concentration

Peculiarities of annihilation of polarized positronium in polarized media

International Nuclear Information System (INIS)

Silenko, A.Ya.

2005-01-01

Features of positronium annihilation (PA) in polarized media are investigated. Strong exchange interaction with nonpaired electrons of paramagnetic atoms essentially accelerates the PA in comparison with annihilation of free positrons. The value of the spin projection on the direction of polarized nonpaired electrons has essential effect on the orthopositronium lifetime and on the width of the gamma spectrum annihilation line. It is shown that these features of PA permit to use it for studying the paramagnetic polarization [ru

Angular distribution coefficients for γ-ray polarization produced in polarized capture reactions

International Nuclear Information System (INIS)

Wulf, E.A.; Guillemette, J.; Weller, H.R.; Seyler, R.G.

1999-01-01

The previous publications have dealt with the angular momentum formalism of both linear and circularly polarized photons in (γ, x) reactions on both polarized and unpolarized targets, and the inverse (capture) reactions initiated by polarized beams. In the present work, utilizing the general formalism of Welton, the authors deal with the linear polarization of the γ-rays which are produced in capture reactions on unpolarized targets, including the possibility of having incident polarized spin 1/2 projectiles. These capture reactions are denoted by a(rvec x, rvec L)c, where rvec x is the incident polarized spin 1/2 projectile and rvec L represents the outgoing polarized γ-ray. They present here the formalism in a convenient form, display a sample table of coefficients, and illustrate its use by means of several examples. A FORTRAN code will be made available for generating similar coefficients for other reactions

Polarization effects. Volume 2

Energy Technology Data Exchange (ETDEWEB)

Courant, E.

1981-01-01

The use of polarized proton beams in ISABELLE is important for several general reasons: (1) With a single longitudinally polarized proton beam, effects involving parity violation can be identified and hence processes involving weak interactions can be separated from those involving strong and electromagnetic interactions. (2) Spin effects are important in the strong interactions and can be useful for testing QCD. The technique for obtaining polarized proton beams in ISABELLE appears promising, particularly in view of the present development of a polarized proton beam for the AGS. Projections for the luminosity in ISABELLE for collisions of polarized protons - one or both beams polarized with longitudinal or transverse polarization - range from 1/100 to 1 times the luminosity for unpolarized protons.

Instrumentation with polarized neutrons

International Nuclear Information System (INIS)

Boeni, P.; Muenzer, W.; Ostermann, A.

2009-01-01

Neutron scattering with polarization analysis is an indispensable tool for the investigation of novel materials exhibiting electronic, magnetic, and orbital degrees of freedom. In addition, polarized neutrons are necessary for neutron spin precession techniques that path the way to obtain extremely high resolution in space and time. Last but not least, polarized neutrons are being used for fundamental studies as well as very recently for neutron imaging. Many years ago, neutron beam lines were simply adapted for polarized beam applications by adding polarizing elements leading usually to unacceptable losses in neutron intensity. Recently, an increasing number of beam lines are designed such that an optimum use of polarized neutrons is facilitated. In addition, marked progress has been obtained in the technology of 3 He polarizers and the reflectivity of large-m supermirrors. Therefore, if properly designed, only factors of approximately 2-3 in neutron intensity are lost. It is shown that S-benders provide neutron beams with an almost wavelength independent polarization. Using twin cavities, polarized beams with a homogeneous phase space and P>0.99 can be produced without significantly sacrificing intensity. It is argued that elliptic guides, which are coated with large m polarizing supermirrors, provide the highest flux.

Marcadores tumorais no câncer de pulmão: um caminho para a terapia biológica

OpenAIRE

PACHECO FERNANDO AZEVEDO; PASCHOAL MARCOS EDUARDO MACHADO; CARVALHO MARIA DA GLÓRIA DA COSTA

2002-01-01

Os avanços recentes na genética e na biologia molecular permitiram a identificação de genes e proteínas produzidos ou superexpressados pelos tumores. Tais produtos, os chamados marcadores tumorais, antes utilizados apenas como ferramentas de diagnóstico e prognóstico, vêm atualmente tomando papel importante no desenvolvimento de novas modalidades de tratamento, direcionadas a quebrar o ciclo biológico da progressão tumoral. Neste artigo, revisa-se o papel de alguns marcadores tumorais tradici...

Feasibility studies of a polarized positron source based on the Bremsstrahlung of polarized electrons

International Nuclear Information System (INIS)

Dumas, J.

2011-09-01

The nuclear and high-energy physics communities have shown a growing interest in the availability of high current, highly-polarized positron beams. A sufficiently energetic polarized photon or lepton incident on a target may generate, via Bremsstrahlung and pair creation within a solid target foil, electron-positron pairs that should carry some fraction of the initial polarization. Recent advances in high current (> 1 mA) spin polarized electron sources at Jefferson Lab offer the perspective of creating polarized positrons from a low energy electron beam. This thesis discusses polarization transfer from electrons to positrons in the perspective of the design optimization of a polarized positron source. The PEPPo experiment, aiming at a measurement of the positron polarization from a low energy (< 10 MeV) highly spin polarized electron beam is discussed. A successful demonstration of this technique would provide an alternative scheme for the production of low energy polarized positrons and useful information for the optimization of the design of polarized positron sources in the sub-GeV energy range. (author)

Dispersing surface-modified imogolite nanotubes in polar and non-polar solvents

Science.gov (United States)

Li, Ming; Brant, Jonathan A.

2018-02-01

Furthering the development of nanocomposite structures, namely membranes for water treatment applications, requires that methods be developed to ensure nanoparticle dispersion in polar and non-polar solvents, as both are widely used in associated synthesis techniques. Here, we report on a two-step method to graft polyvinylpyrrolidone (PVP), and a one-step method for octadecylphosphonic acid (OPA), onto the outer surfaces of imogolite nanotubes. The goal of these approaches was to improve and maintain nanotube dispersion in polymer compatible polar and non-polar solvents. The PVP coating modified the imogolite surface charge from positive to weakly negative at pH ≤ 9; the OPA made it weakly positive at acidic pH values to negative at pH ≥ 7. The PVP surface coating stabilized the nanotubes through steric hindrance in polar protic, dipolar aprotic, and chloroform. In difference to the PVP, the OPA surface coating allowed the nanotubes to be dispersed in n-hexane and chloroform, but not in the polar solvents. The lack of miscibility in the polar solvents, as well as the better dispersion in n-hexane, was attributed to the stronger hydrophobicity of the OPA polymer relative to the PVP. [Figure not available: see fulltext.

Use of internal scintillator radioactivity to calibrate DOI function of a PET detector with a dual-ended-scintillator readout

International Nuclear Information System (INIS)

Bircher, Chad; Shao Yiping

2012-01-01

Purpose: Positron emission tomography (PET) detectors that use a dual-ended-scintillator readout to measure depth-of-interaction (DOI) must have an accurate DOI function to provide the relationship between DOI and signal ratios to be used for detector calibration and recalibration. In a previous study, the authors used a novel and simple method to accurately and quickly measure DOI function by irradiating the detector with an external uniform flood source; however, as a practical concern, implementing external uniform flood sources in an assembled PET system is technically challenging and expensive. In the current study, therefore, the authors investigated whether the same method could be used to acquire DOI function from scintillator-generated (i.e., internal) radiation. The authors also developed a method for calibrating the energy scale necessary to select the events within the desired energy window. Methods: The authors measured the DOI function of a PET detector with lutetium yttrium orthosilicate (LYSO) scintillators. Radiation events originating from the scintillators' internal Lu-176 beta decay were used to measure DOI functions which were then compared with those measured from both an external uniform flood source and an electronically collimated external point source. The authors conducted these studies with several scintillators of differing geometries (1.5 x 1.5 and 2.0 x 2.0 mm 2 cross-section area and 20, 30, and 40 mm length) and various surface finishes (mirror-finishing, saw-cut rough, and other finishes in between), and in a prototype array. Results: All measured results using internal and external radiation sources showed excellent agreement in DOI function measurement. The mean difference among DOI values for all scintillators measured from internal and external radiation sources was less than 1.0 mm for different scintillator geometries and various surface finishes. Conclusions: The internal radioactivity of LYSO scintillators can be used to

Modeling optical and UV polarization of AGNs. IV. Polarization timing

Science.gov (United States)

Rojas Lobos, P. A.; Goosmann, R. W.; Marin, F.; Savić, D.

2018-03-01

Context. Optical observations cannot resolve the structure of active galactic nuclei (AGN), and a unified model for AGN was inferred mostly from indirect methods, such as spectroscopy and variability studies. Optical reverberation mapping allowed us to constrain the spatial dimension of the broad emission line region and thereby to measure the mass of supermassive black holes. Recently, reverberation was also applied to the polarized signal emerging from different AGN components. In principle, this should allow us to measure the spatial dimensions of the sub-parsec reprocessing media. Aim. We conduct numerical modeling of polarization reverberation and provide theoretical predictions for the polarization time lag induced by different AGN components. The model parameters are adjusted to the observational appearance of the Seyfert 1 galaxy NGC 4151. Methods: We modeled scattering-induced polarization and tested different geometries for the circumnuclear dust component. Our tests included the effects of clumpiness and different dust prescriptions. To further extend the model, we also explored the effects of additional ionized winds stretched along the polar direction, and of an equatorial scattering ring that is responsible for the polarization angle observed in pole-on AGN. The simulations were run using a time-dependent version of the STOKES code. Results: Our modeling confirms the previously found polarization characteristics as a function of the observer`s viewing angle. When the dust adopts a flared-disk geometry, the lags reveal a clear difference between type 1 and type 2 AGN. This distinction is less clear for a torus geometry where the time lag is more sensitive to the geometry and optical depth of the inner surface layers of the funnel. The presence of a scattering equatorial ring and ionized outflows increased the recorded polarization time lags, and the polar outflows smooths out dependence on viewing angle, especially for the higher optical depth of the

Study on polarized optical flow algorithm for imaging bionic polarization navigation micro sensor

Science.gov (United States)

Guan, Le; Liu, Sheng; Li, Shi-qi; Lin, Wei; Zhai, Li-yuan; Chu, Jin-kui

2018-05-01

At present, both the point source and the imaging polarization navigation devices only can output the angle information, which means that the velocity information of the carrier cannot be extracted from the polarization field pattern directly. Optical flow is an image-based method for calculating the velocity of pixel point movement in an image. However, for ordinary optical flow, the difference in pixel value as well as the calculation accuracy can be reduced in weak light. Polarization imaging technology has the ability to improve both the detection accuracy and the recognition probability of the target because it can acquire the extra polarization multi-dimensional information of target radiation or reflection. In this paper, combining the polarization imaging technique with the traditional optical flow algorithm, a polarization optical flow algorithm is proposed, and it is verified that the polarized optical flow algorithm has good adaptation in weak light and can improve the application range of polarization navigation sensors. This research lays the foundation for day and night all-weather polarization navigation applications in future.

Development of GAGG depth-of-interaction (DOI) block detectors based on pulse shape analysis

International Nuclear Information System (INIS)

Yamamoto, Seiichi; Kobayashi, Takahiro; Yeol Yeom, Jung; Morishita, Yuki; Sato, Hiroki; Endo, Takanori; Usuki, Yoshiyuki; Kamada, Kei; Yoshikawa, Akira

2014-01-01

A depth-of-interaction (DOI) detector is required for developing a high resolution and high sensitivity PET system. Ce-doped Gd 3 Al 2 Ga 3 O 12 (GAGG fast: GAGG-F) is a promising scintillator for PET applications with high light output, no natural radioisotope and suitable light emission wavelength for semiconductor based photodetectors. However, no DOI detector based on pulse shape analysis with GAGG-F has been developed to date, due to the lack of appropriate scintillators of pairing. Recently a new variation of this scintillator with different Al/Ga ratios—Ce-doped Gd 3 Al 2.6 Ga 2.4 O 12 (GAGG slow: GAGG-S), which has slower decay time was developed. The combination of GAGG-F and GAGG-S may allow us to realize high resolution DOI detectors based on pulse shape analysis. We developed and tested two GAGG phoswich DOI block detectors comprised of pixelated GAGG-F and GAGG-S scintillation crystals. One phoswich block detector comprised of 2×2×5 mm pixel that were assembled into a 5×5 matrix. The DOI block was optically coupled to a silicon photomultiplier (Si-PM) array (Hamamatsu MPPC S11064-050P) with a 2-mm thick light guide. The other phoswich block detector comprised of 0.5×0.5×5 mm (GAGG-F) and 0.5×0.5×6 mm 3 (GAGG-S) pixels that were assembled into a 20×20 matrix. The DOI block was also optically coupled to the same Si-PM array with a 2-mm thick light guide. In the block detector of 2-mm crystal pixels (5×5 matrix), the 2-dimensional histogram revealed excellent separation with an average energy resolution of 14.1% for 662-keV gamma photons. The pulse shape spectrum displayed good separation with a peak-to-valley ratio of 8.7. In the block detector that used 0.5-mm crystal pixels (20×20 matrix), the 2-dimensional histogram also showed good separation with energy resolution of 27.5% for the 662-keV gamma photons. The pulse shape spectrum displayed good separation with a peak-to-valley ratio of 6.5. These results indicate that phoswich DOI

Design and simulation of a novel circularly polarized antenna with polarization reconfigurable characteristics

Directory of Open Access Journals (Sweden)

Zhang Hai

2016-01-01

Full Text Available A novel circularly polarized antenna with polarization reconfigurable characteristics was designed using co-simulation of Ansoft HFSS and Designer software. It consists of a dual-polarized antenna and phase switching network which act as the feed network for the dual-polarized antenna. The phase switching network was designed based on a Wilkinson power divider, where the output port was connected with SPDT to form a switching network. By controlling the SPDT state-off / on, the phase difference of the two ports could be alternated, which generated the orthogonal modes between the two ports of dual-polarized antenna. So that Left-hand circular polarization (LHCP and Right-hand circular polarization (RHCP could be achieved. The simulation shown that reflection coefficient was less than -12 dB and the axial ratio was below 3 dB between 1.8 GHz and 2.4 GHz with polarization reconfigurable characteristics.

Solución numérica de modelos biológicos de reacción difusión en dominios fijos mediante el método de los elementos finitos

OpenAIRE

Libardo Andrés González; Juan Carlos Vanegas; Diego Alexander Garzón

2009-01-01

Múltiples fenómenos biológicos se han descrito mediante modelos matemáticos formulados a partir de ecuaciones de reacción difusión. La solución de este tipo de ecuaciones da lugar a la formación de patrones espacio-temporales que se ajustan a la realidad biológica del fenómeno modelado. En este artículo se describe la implementación numérica de tres modelos de reacción difusión bien referenciados: el modelo de morfogénesis de Schnakenberg, y los modelos de reacción cinética de Gierer-Meinhard...

VIIRS-J1 Polarization Narrative

Science.gov (United States)

Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith; Butler, James; Meister, Gerhard; Thome, Kurtis J.

2015-01-01

The VIS/NIR bands polarization sensitivity of Joint Polar Satellite Sensor 1 (JPSS1) Visible/Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5%, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4%, 4.4%, 3.1%, and 4.3%, respectively with a polarization characterization uncertainty of less than 0.3%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands was mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the instruments two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at Goddard and NIST and the use of NIST's T-SIRCUS for polarization testing and associated analyses and results.

Polarization of Be stars

International Nuclear Information System (INIS)

Johns, M.W.

1975-01-01

Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

Ionic polarization

International Nuclear Information System (INIS)

Mahan, G.D.

1992-01-01

Ferroelectricity occurs in many different kinds of materials. Many of the technologically important solids, which are ferroelectric, can be classified as ionic. Any microscopic theory of ferroelectricity must contain a description of local polarization forces. We have collaborated in the development of a theory of ionic polarization which is quite successful. Its basic assumption is that the polarization is derived from the properties of the individual ions. We have applied this theory successfully to diverse subjects as linear and nonlinear optical response, phonon dispersion, and piezoelectricity. We have developed numerical methods using the local Density approximation to calculate the multipole polarizabilities of ions when subject to various fields. We have also developed methods of calculating the nonlinear hyperpolarizability, and showed that it can be used to explain light scattering experiments. This paper elaborates on this polarization theory

Aprendizagem motora baseada em demonstrações de movimento biológico Motor learning based on biological motion demonstrations

Directory of Open Access Journals (Sweden)

Sérgio Tosi Rodrigues

2012-12-01

Full Text Available O objetivo deste estudo foi avaliar o processo de aprendizagem motora de uma habilidade complexa da Ginástica Artística a partir da observação de demonstrações de modelos de pontos de luz e vídeo. Dezesseis participantes divididas em grupos dos respectivos modelos executaram um pré-teste, seguido de 100 tentativas de uma parada de mãos, igualmente distribuídas em blocos de 10 tentativas em dois dias, alternando períodos de demonstração e prática, com um teste de retenção após um dia. Cinemática de braço, tronco e perna das participantes possibilitaram análise da semelhança entre a coordenação de cada participante e do modelo e do tempo de movimento; a performance das participantes também foi avaliada por duas especialistas em Ginástica Artística. Ambas as análises indicaram que os grupos não diferiram. Os resultados são discutidos em termos da hipótese de suficiência de informação nos modelos de movimento biológico particularmente aplicada ao processo de aprendizagem de habilidades motoras complexas.The aim of this study was to evaluate the motor learning process of a complex Artistic Gymnastics skill following demonstrations of point-light and video models. Sixteen participants divided into the respective model groups performed a pre-test and 100 trials of a handstand, equally distributed in blocks of 10 trials in two days, alternating periods of demonstration and practice, with retention test a day later. Participants' kinematics of arm, trunk, and leg was used to analyze the coordination similarities between each participant and the model and movement time; participants' performance was also evaluated by two Artistic Gymnastics experts. Both analyses revealed that the groups did not differ. Results are discussed in terms of the hypothesis of information sufficiency in biological motion models particularly applied to the learning process of complex motor skills.

Bioseguridad y armas biológicas:\tLa amenaza de Andrómeda (1971

Directory of Open Access Journals (Sweden)

Manuel SÁNCHEZ

2016-11-01

Full Text Available La amenaza de Andrómeda es la adaptación cinematográfica de la obra homónima escrita por Michael Crichton. Puede considerarse como la película más “microbiológica” del Séptimo Arte. Dirigida por Robert Wise, este tecno-thriller describe los esfuerzos de un equipo de científicos para caracterizar y contener a un microorganismo patógeno extraterrestre. A pesar de haber sido realizada hace 40 años, se tratan temas de plena actualidad como es el de las armas biológicas, las medidas de aislamiento y protección, la automatización en los procedimientos sanitarios y la toma de decisiones ante una situación grave e inesperada.

Internação domiciliar: risco de exposição biológica para a equipe de saúde

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Rosely Moralez de Figueiredo

2012-02-01

Full Text Available Estudo exploratório e prospectivo, de abordagem quantitativa que visou caracterizar as ações que envolviam risco biológico durante o atendimento de profissionais no Serviço de Internação Domiciliar do Hospital Municipal de São Carlos, SP. No acompanhamento das 159 visitas, realizadas no período de junho de 2008 a janeiro de 2009, foram observados 347 procedimentos sendo que, entre os com risco de exposição biológica, foram identificados curativos (31,1%, glicemia capilar (14,4% e acesso vascular (3,1%. A ocorrência de adesão à higienização prévia das mãos foi de 21,5%, 66,3% no uso de luvas e de 83,5% no descarte adequado do perfurocortante. Conclui-se que esses profissionais estão sujeitos a riscos semelhantes aos encontrados na área hospitalar, uma vez que também manipulam sangue e material perfurocortante com muita frequência e apresentam baixa adesão às precauções padrão. Estudos que avaliem a influência das características dos domicílios nesse risco devem ser estimulados.

POLARIZED BEAMS: 1 - Longitudinal electron spin polarization at HERA

Energy Technology Data Exchange (ETDEWEB)

Anon.

1994-09-15

Wednesday 4 May marked a turning point in the art of the manipulation of spins in electron storage rings: longitudinal electron spin polarization (with the spins oriented along the electrons' direction of motion) was established in the electron ring of HERA, the electronproton collider at DESY in Hamburg. A polarization level of about 55% was obtained and polarizations of over 60% were reproducibly obtained in the following days. The beam energy was 27.52 GeV, corresponding to half integer spin tune of 62.5.

O significado do acidente de trabalho com material biológico para os profissionais de enfermagem El significado del accidente de trabajo con material biológico para los profesionales de enfermería The significance of accidents involving biological material to nursing professionals

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Maristela Aparecida Magri Magagnini

2011-06-01

Full Text Available O objetivo deste estudo foi compreender o significado dos acidentes de trabalho com exposição a material biológico na perspectiva dos profissionais de enfermagem. De caráter exploratório com abordagem qualitativa pela análise de conteúdo de Bardin. No período de 2001 a 2006 ocorreram 87 acidentes com material biológico, sendo que destes, oito eram soropositivos para hepatite B e C e Síndrome da Imunodeficiência Adquirida/Vírus da Imunodeficiência Humana. Para coleta de dados utilizou-se entrevista com perguntas norteadoras. Ao indagar esses profissionais sobre o significado dos acidentes, emergiram quatro categorias: situação de risco; percepção de perigo; fatalidade e sentimentos. Embora não seja estratégia de esclarecimento, mas é fato que organização de trabalho e ações educativas tem impacto considerável para diminuir esse tipo de acidente, diminuindo prejuízos na vida dos acidentados.El objetivo de este estudio ha sido comprender el significado de accidentes de trabajo con exposición a material biológico, desde la perspectiva de los profesionales de enfermería. De carácter exploratorio con enfoque cualitativo por el análisis de contenido de Bardin. En el período de 2001 a 2006 ocurrieron 87 accidentes con material biológico, de estos, ocho eran seropositivos para hepatitis B y C y Síndrome de la Inmunodeficiencia Adquirida/Virus de la Inmunodeficiencia Humana. Para recoger datos se ha utilizado entrevista con preguntas. Al preguntar a esos profesionales sobre el significado de los accidentes, han surgido cuatro categorías: situación de riesgo, percepción de peligro, fatalidad y sentimientos. Aunque no sea estrategia de aclaración, pero es un hecho que la organización de trabajo y acciones educativas tienen impacto considerable para disminuir ese tipo de accidente, disminuyendo perjuicios en la vida de los accidentados.The objective of this present study was to understand the significance of

Las técnicas de secuenciación masiva en el estudio de la diversidad biológica.

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Unai López de Heredia

2016-01-01

Full Text Available Las técnicas de análisis genómico que se basan en la secuenciación masiva han supuesto una revolución en la última década no sólo en biomedicina o agronomía, sino también en el estudio de la diversidad biológica. Las plataformas de secuenciación de segunda y tercera generación que vienen a complementar a la tradicional secuenciación por el método Sanger, permiten analizar un gran número de individuos obteniendo una profundidad de secuenciación significativa de sus genomas o transcriptomas. Así, aunque todavía de manera incipiente, se vienen realizando estudios sobre la flora y fauna silvestre a escala poblacional, con especial énfasis en la determinación de patrones adaptativos frente a los cambios ambientales. En la presente revisión se describe la situación actual de las plataformas de secuenciación masiva, señalando sus ventajas y limitaciones para el análisis en organismos no modelo, para a continuación detallar las bases de dos de las técnicas más populares que se benefician de la secuenciación masiva (RAD-seq y RNA-seq y señalar algunos ejemplos de su uso para el estudio de la diversidad biológica.

Polarized Electrons at Jefferson Laboratory

Energy Technology Data Exchange (ETDEWEB)

Sinclair, C.K.

1997-12-31

The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously.initial operational experience with the polarized source will be presented.

Adapting the HSV polarization-color mapping for regions with low irradiance and high polarization.

Science.gov (United States)

Scott Tyo, J; Ratliff, Bradley M; Alenin, Andrey S

2016-10-15

Many mappings from polarization into color have been developed so that polarization information can be displayed. One of the most common of these maps the angle of linear polarization into color hue and degree of linear polarization into color saturation, while preserving the irradiance information from the polarization data. While this strategy enjoys wide popularity, there is a large class of polarization images for which it is not ideal. It is common to have images where the strongest polarization signatures (in terms of degree of polarization) occur in regions of relatively low irradiance: either in shadow in reflective bands or in cold regions in emissive bands. Since the irradiance is low, the chromatic properties of the resulting images are generally not apparent. Here we present an alternate mapping that uses the statistics of the angle of polarization as a measure of confidence in the polarization signature, then amplifies the irradiance in regions of high confidence, and leaves it unchanged in regions of low confidence. Results are shown from an LWIR and a visible spectrum imager.

Polarized Moessbauer transitions

International Nuclear Information System (INIS)

Barb, D.

1975-01-01

Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

Polarization division multiple access with polarization modulation for LOS wireless communications

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Cao Bin

2011-01-01

Full Text Available Abstract In this paper, we discuss a potential multiple access and modulation scheme based on polarized states (PS of electromagnetic (EM waves for line-of-sight (LOS communications. The proposed scheme is theoretic different from the existing polar modulation for EDGE and WCDMA systems. We propose the detailed bit representation (modulation and multiple access scheme using PS. Because of the inflexibility of polarization information in the time and frequency domains, as well as independence of frequency and space, the polarization information can be used independently for wireless communications, i.e., another independent resource domain that can be utilized. Due to the independence between the PS and the specific features of signals (such as waveform, bandwidth and data rate, the discussed polarization division multiple access (PDMA and polarization modulation (PM are expected to improve the spectrum utilization effectively. It is proved that the polarization filtering technique can be adopted in the PDMA-PM wireless communications to separate the multiuser signals and demodulate the bit information representing by PS for desired user. Some theoretical analysis is done to demonstrate the feasibility of the proposed scheme, and the simulation results are made to evaluate the performance of the suggested system.

Progranulin and the receptor tyrosine kinase EphA2, partners in crime?

Science.gov (United States)

Chitramuthu, Babykumari; Bateman, Andrew

2016-01-01

Progranulin is a secreted protein with roles in tumorigenesis, inflammation, and neurobiology, but its signaling receptors have remained unclear. In this issue, Neill et al. (2016. J. Cell Biol. https://doi.org/10.1083/jcb.201603079) identify the tyrosine kinase EphA2 as a strong candidate for such a receptor, providing insight into progranulin and EphA2 signaling. PMID:27903608

Spatial resolution of cAMP signaling by soluble adenylyl cyclase

Science.gov (United States)

Caldieri, Giusi

2016-01-01

G protein–coupled receptor signaling starts at the plasma membrane and continues at endosomal stations. In this issue, Inda et al. (2016. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201512075) show that different forms of adenylyl cyclase are activated at the plasma membrane versus endosomes, providing a rationale for the spatial encoding of cAMP signaling. PMID:27402955

From DNA binding to transcriptional activation: Is the TALE complete?

Science.gov (United States)

Bobola, Nicoletta

2017-09-04

How transcription factors (TFs) control enhancer and promoter functions to effect changes in gene expression is an important question. In this issue, Hau et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201701154) show that the TALE TF MEIS recruits the histone modifier PARP1/ARTD1 at promoters to decompact chromatin and activate transcription. © 2017 Bobola.

Polarization at SLC

International Nuclear Information System (INIS)

Swartz, M.L.

1988-07-01

The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

Polarized electrons at Jefferson laboratory

International Nuclear Information System (INIS)

Sinclair, C.K.

1998-01-01

The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously. Initial operational experience with the polarized source will be presented. copyright 1998 American Institute of Physics

Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis

Science.gov (United States)

Sun, Junqiang; Xiong, Xiaoxiong; Waluschka, Eugene; Wang, Menghua

2016-01-01

The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of five instruments onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite that launched from Vandenberg Air Force Base, California, on October 28, 2011. It is a whiskbroom radiometer that provides +/-56.28deg scans of the Earth view. It has 22 bands, among which 14 are reflective solar bands (RSBs). The RSBs cover a wavelength range from 410 to 2250 nm. The RSBs of a remote sensor are usually sensitive to the polarization of incident light. For VIIRS, it is specified that the polarization factor should be smaller than 3% for 410 and 862 nm bands and 2.5% for other RSBs for the scan angle within +/-45deg. Several polarization sensitivity tests were performed prelaunch for SNPP VIIRS. The first few tests either had large uncertainty or were less reliable, while the last one was believed to provide the more accurate information about the polarization property of the instrument. In this paper, the measured data in the last polarization sensitivity test are analyzed, and the polarization factors and phase angles are derived from the measurements for all the RSBs. The derived polarization factors and phase angles are band, detector, and scan angle dependent. For near-infrared bands, they also depend on the half-angle mirror side. Nevertheless, the derived polarization factors are all within the specification, although the strong detector dependence of the polarization parameters was not expected. Compared to the Moderate Resolution Imaging Spectroradiometer on both Aqua and Terra satellites, the polarization effect on VIIRS RSB is much smaller.

Tratamento de águas residuárias de suinocultura em reator UASB e filtro anaeróbio em série seguidos de filtro biológico percolador Treatment of swine wastewater in UASB reactor and anaerobic filter in series followed of trickling filter

Directory of Open Access Journals (Sweden)

Rose Maria Duda

2011-03-01

Full Text Available Avaliou-se o desempenho de um reator anaeróbio de fluxo ascendente com manta de lodo (UASB seguido de um filtro anaeróbio, instalados em série, com volume total de 300 L e 190 L, respectivamente, no tratamento de águas residuárias de suinocultura. As cargas orgânicas volumétricas aplicadas no reator UASB foram de 12,4;15,5; 23,2 e 26,3 g DQOtotal (L d-1. Para o pós-tratamento do efluente do sistema anaeróbio em dois estágios utilizou-se um filtro biológico percolador com volume total de 250 L. O meio suporte utilizado nos filtros anaeróbio e biológico percolador foi composto por anéis de bambu. No sistema de tratamento anaeróbio e de pós-tratamento foram observadas eficiências médias de remoção de demanda química de oxigênio total (DQOtotal, sólidos suspensos totais (SST, nitrogênio total (NT, fósforo total (P-total, Cu e Zn de até 98, 99, 78, 84, 99 e 98%, respectivamente.The performance of an upflow anaerobic sludge blanket (UASB followed by the anaerobic filter, installed in series, was evaluated for the treatment of swine wastewater. The total volume of UASB and anaerobic filter were of 300 L and 190 L, respectively. The organic load rate applied on the reactor UASB were of 12.4, 15.5, 23.2 and 26.3 g total COD (L d-1. For the post-treatment of effluent the anaerobic system was used a trickling filter with total volume of 250 L. The supports used in the anaerobic filter and trickling filter were composed by bamboo rings. The efficiencies of removal the chemical oxygen demand, total solids suspended, nitrogen, total phosphorus, Cu and Zn were of up to 98, 99, 78, 84, 99 and 98%, respectively, for the anaerobic and aerobic treatment system.

A Si nanocube array polarizer

Science.gov (United States)

Chen, Linghua; Jiang, Yingjie; Xing, Li; Yao, Jun

2017-10-01

We have proposed a full dielectric (silicon) nanocube array polarizer based on a silicon dioxide substrate. Each polarization unit column includes a plurality of equal spaced polarization units. By optimizing the length, the width, the height of the polarization units and the center distance of adjacent polarization unit (x direction and y direction), an extinction ratio (ER) of higher than 25dB was obtained theoretically when the incident light wavelength is 1550nm. while for applications of most polarization optical elements, ER above 10dB is enough. With this condition, the polarizer we designed can work in a wide wavelength range from 1509.31nm to 1611.51nm. Compared with the previous polarizer, we have introduced a polarizer which is a full dielectric device, which solves the problems of low efficiency caused by Ohmic loss and weak coupling. Furthermore, compared with the existing optical polarizers, our polarizer has the advantages of thin thickness, small size, light weight, and low processing difficulty, which is in line with the future development trend of optical elements.

Polarization: A Must for Fusion

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Guidal M.

2012-10-01

Full Text Available Recent realistic simulations confirm that the polarization of the fuel would improve significantly the DT fusion efficiency. We have proposed an experiment to test the persistence of the polarization in a fusion process, using a terawatt laser hitting a polarized HD target. The polarized deuterons heated in the plasma induced by the laser can fuse producing a 3He and a neutron in the final state. The angular distribution of the neutrons and the change in the corresponding total cross section are related to the polarization persistence. The experimental polarization of DT fuel is a technological challenge. Possible paths for Magnetic Confinement Fusion (MCF and for Inertial Confinement Fusion (ICF are reviewed. For MCF, polarized gas can be used. For ICF, cryogenic targets are required. We consider both, the polarization of gas and the polarization of solid DT, emphasizing the Dynamic Nuclear polarization (DNP of HD and DT molecules.

PolarTREC—A Model Program for Taking Polar Literacy into the Future

Science.gov (United States)

Warburton, J.; Timm, K.; Larson, A. M.

2009-12-01

Polar TREC—Teachers and Researchers Exploring and Collaborating, is a three-year (2007-2009) NSF-funded International Polar Year (IPY) teacher professional development program that advances Science, Technology, Engineering, and Mathematics (STEM) education by improving teacher content knowledge and instructional practices through Teacher Research Experiences (TRE) in the Arctic and Antarctic. Leveraging profound changes and fascinating science taking place in the polar regions, PolarTREC broadly disseminates activities and products to students, educators, researchers, and the public, connecting them with the Arctic and Antarctica and sustaining the widespread interest in the polar regions and building on the enthusiasm that was generated through IPY. Central to the PolarTREC Teacher Research Experience Model, over 40 teachers have spent two to eight weeks participating in hands-on research in the polar regions and sharing their experiences with diverse audiences via live events, online multimedia journals, and interactive bulletin boards. The Connecting Arctic/Antarctic Researchers and Educators (CARE) Network unifies learning community members participants, alumni, and others, developing a sustainable association of education professionals networking to share and apply polar STEM content and pedagogical skills. Educator and student feedback from preliminary results of the program evaluation has shown that PolarTREC’s comprehensive program activities have many positive impacts on educators and their ability to teach science concepts and improve their teaching methods. Additionally, K-12 students polled in interest surveys showed significant changes in key areas including amount of time spent in school exploring research activities, importance of understanding science for future work, importance of understanding the polar regions as a person in today’s world, as well as increased self-reported knowledge and interest in numerous science content areas. Building

Generating highly polarized nuclear spins in solution using dynamic nuclear polarization

DEFF Research Database (Denmark)

Wolber, J.; Ellner, F.; Fridlund, B.

2004-01-01

A method to generate strongly polarized nuclear spins in solution has been developed, using Dynamic Nuclear Polarization (DNP) at a temperature of 1.2K, and at a field of 3.354T, corresponding to an electron spin resonance frequency of 94GHz. Trityl radicals are used to directly polarize 13C...... and other low-γ nuclei. Subsequent to the DNP process, the solid sample is dissolved rapidly with a warm solvent to create a solution of molecules with highly polarized nuclear spins. Two main applications are proposed: high-resolution liquid state NMR with enhanced sensitivity, and the use...

Polarized Light Microscopy

Science.gov (United States)

Frandsen, Athela F.

2016-01-01

Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

Non-polar InGaN quantum dot emission with crystal-axis oriented linear polarization

Energy Technology Data Exchange (ETDEWEB)

Reid, Benjamin P. L., E-mail: benjamin.reid@physics.ox.ac.uk; Chan, Christopher C. S.; Taylor, Robert A. [Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Kocher, Claudius [Department of Physics, University of Konstanz, Konstanz 78457 (Germany); Zhu, Tongtong; Oehler, Fabrice; Oliver, Rachel A. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2015-04-27

Polarization sensitive photoluminescence is performed on single non-polar InGaN quantum dots. The studied InGaN quantum dots are found to have linearly polarized emission with a common polarization direction defined by the [0001] crystal axis. Around half of ∼40 studied dots have a polarization degree of 1. For those lines with a polarization degree less than 1, we can resolve fine structure splittings between −800 μeV and +800 μeV, with no clear correlation between fine structure splitting and emission energy.

The Physics of Polarization

Science.gov (United States)

Landi Degl'Innocenti, Egidio

2015-10-01

The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

Fiber-Based Polarization Diversity Detection for Polarization-Sensitive Optical Coherence Tomography

Directory of Open Access Journals (Sweden)

Hamid Pahlevaninezhad

2014-09-01

Full Text Available We present a new fiber-based polarization diversity detection (PDD scheme for polarization sensitive optical coherence tomography (PSOCT. This implementation uses a new custom miniaturized polarization-maintaining fiber coupler with single mode (SM fiber inputs and polarization maintaining (PM fiber outputs. The SM fiber inputs obviate matching the optical lengths of the two orthogonal OCT polarization channels prior to interference while the PM fiber outputs ensure defined orthogonal axes after interference. Advantages of this detection scheme over those with bulk optics PDD include lower cost, easier miniaturization, and more relaxed alignment and handling issues. We incorporate this PDD scheme into a galvanometer-scanned OCT system to demonstrate system calibration and PSOCT imaging of an achromatic quarter-wave plate, fingernail in vivo, and chicken breast, salmon, cow leg, and basa fish muscle samples ex vivo.

Bringing Society to a Changing Polar Ocean: Polar Interdisciplinary Coordinated Education (ICE)

Science.gov (United States)

Schofield, O.

2015-12-01

Environmental changes in the Arctic and Antarctic appear to be accelerating and scientists are trying to understand both the patterns and the impacts of change. These changes will have profound impact on humanity and create a need for public education about these critical habitats. We have focused on a two-pronged strategy to increase public awareness as well as enable educators to discuss comfortably the implications of climate change. Our first focus is on entraining public support through the development of science documentaries about the science and people who conduct it. Antarctic Edge is a feature length award-winning documentary about climate change that has been released in May 2015 and has garnered interest in movie theatres and on social media stores (NetFlix, ITunes). This broad outreach is coupled with our group's interest assisting educators formally. The majority of current polar education is focused on direct educator engagement through personal research experiences that have impact on the participating educators' classrooms. Polar Interdisciplinary Coordinated Education (ICE) proposes to improve educator and student engagement in polar sciences through exposure to scientists and polar data. Through professional development and the creation of data tools, Polar ICE will reduce the logistical costs of bringing polar science to students in grades 6-16. We will provide opportunities to: 1) build capacity of polar scientists in communicating and engaging with diverse audiences; 2) create scalable, in-person and virtual opportunities for educators and students to engage with polar scientists and their research through data visualizations, data activities, educator workshops, webinars, and student research symposia; and 3) evaluate the outcomes of Polar ICE and contribute to our understanding of science education practices. We will use a blended learning approach to promote partnerships and cross-disciplinary sharing. This combined multi-pronged approach

Atividades biológicas das lectinas PHA, WGA, jacalina e artocarpina Biological activities of PHA, WGA, jacalin and artocarpin lectins

Directory of Open Access Journals (Sweden)

Ana Maria Sell

2000-05-01

Full Text Available As lectinas são (glicoproteínas que se ligam a açúcares. O interesse destas moléculas na investigação científica se deve às diversas atividades biológicas a elas atribuídas. Além da identificação de grupos sangüíneos, da caracterização de microorganismos e da estimulação mitogênica de células imunes, as lectinas estão envolvidas nos processos de reconhecimento e das interações celulares. No presente trabalho, revisamos algumas atividades biológicas das lectinas PHA (fitohemaglutinina de Phaseolus vulgaris, WGA (aglutinina de germe de trigo, jacalina e artocarpina (lectinas de Artocarpus integrifolia. PHA, jacalina e artocarpina são mitogênicas para os linfócitos, estimulam a produção de citocinas endógenas, a atração e a ativação de leucócitos. WGA é uma lectina não-mitogênica, no entanto, modula a resposta de defesa estimulando a liberação de superóxido pelos neutrófilos. O entendimento das atividades biológicas permitirá o uso destas moléculas como uma ferramenta útil no diagnóstico e tratamento de muitas doenças.Lectins are ubiquitous (glycoproteins, which exhibit a specific and reversibly carbohydrate binding activity. Because of their structural complexity and variability, they can participate in many physiological functions. Besides the blood groups identification, microorganism characterization and mitogenic immune cell proliferation, they are involved in the cell recognition and cell-cell interaction. In the present work we revised some biological activities of the PHA (Phaseolus vulgaris phytohemagglutinin, WGA (wheat germ agglutinin, jacalin and artocarpin (Artocarpus integrifolia lectins. PHA, jacalin and artocarpin may stimulate lymphocyte proliferation, attract and activate mononuclear cells and stimulate endogenous citokines production. WGA is a nonmitogenic lectin, however it may stimulate neutrophil superoxide production. The understanding of the lectin biological activities may

Guerra biológica, bioterrorismo e saúde pública Biological warfare, bioterrorism and public health

Directory of Open Access Journals (Sweden)

Luiz Jacintho da Silva

2001-12-01

Full Text Available O uso de agentes biológicos como arma não é novidade para a humanidade. Durante séculos, até a atualidade, a guerra biológica tem sido objeto de muita pesquisa e especulação, mas de pouca ação. O medo de efeitos contrários e dúvidas sobre sua eficiência como armas devem ter limitado seu uso. Recentemente, se verificou uma nova forma de terrorismo, empregando agentes infecciosos, devagar e sem muito alarde, até as ocorrências recentes com o Bacillus anthracis nos Estados Unidos. A varíola é possivelmente o mais devastador desses agentes. Menos de 25 anos passados desde sua erradicação, a saúde pública tem que lidar com a possibilidade de sua re-introdução. O cenário da re-introdução da varíola no Brasil é discutido.Biological agents as weapons are not new to mankind. For centuries and into the present, biological warfare has been the subject of much research and speculation, but little action. Their limited use has probably been due to fear of unexpected counter-effects and doubts about their efficiency as weapons. Recently a new form of terrorism employing infectious agents has emerged slowly and without much fanfare, until the recent events with Bacillus anthracis in the United States. Smallpox is potentially the most devastating of these agents. Less than 25 years after the eradication of smallpox, the public health field is now forced to deal with the possibility of its re-introduction. The author discusses the scenario of smallpox re-introduction into Brazil.

Techniques in polarization physics

International Nuclear Information System (INIS)

Clausnitzer, G.

1974-01-01

A review of the current status of the technical tools necessary to perform different kinds of polarization experiments is presented, and the absolute and relative accuracy with which data can be obtained is discussed. A description of polarized targets and sources of polarized fast neutrons is included. Applications of polarization techniques to other fields is mentioned briefly. (14 figures, 3 tables, 110 references) (U.S.)

Polarization: A must for fusion

Directory of Open Access Journals (Sweden)

Didelez J.-P.

2013-11-01

Full Text Available The complete polarization of DT fuel would increase the fusion reactivity by 50% in magnetic as well as in inertial confinements. The persistence of polarization in a fusion process could be tested, using a terawatt laser hitting a polarized HD target. The polarized deuterons heated in the plasma induced by the laser can fuse producing a 3He and a neutron in the final state. The angular distribution of the emitted neutrons and the change in the corresponding total Cross Section (CS can sign the polarization persistence. The polarization of solid H2, D2 or T2 Hydrogen isotopes is very difficult. However, it has been possible to polarize HD, a hetero-molecular form of Hydrogen, by static polarization, at very low temperature and very high field. The radioactivity of DT molecules forbids there high polarization by the static method, therefore one has to develop the Dynamic Nuclear Polarization (DNP by RF transitions. The DNP of HD has been investigated in the past. The magnetic properties of HD and DT molecules are very similar, it is therefore expected that any polarization result obtained with HD could be extrapolated to DT.

An elliptically-polarizing undulator with phase adjustable energy and polarization

International Nuclear Information System (INIS)

Lidia, S.

1993-08-01

The authors present a planar helical undulator designed to produce elliptically polarized light. Helical magnetic fields may be produced by a variety of undulators with four parallel cassettes of magnets. In their design, all cassettes are mounted in two planes on slides so that they may be moved parallel to the electron beam. This allows the undulator to produce x-rays of left- or right-handed elliptical or circular polarization as well as horizontal or vertical linear polarization. In model calculations, they have found that by sliding the top pair of rows with respect to the bottom pair, or the left pair with respect to the right pair, they retain the polarization setting but change the magnetic field strength, and hence the x-ray energy. This allows them to select both energy and polarization by independent phase adjustments alone, without changing the gap between the rows. Such a design may be simpler to construct than an adjustable gap machine. The authors present calculations that model its operation and its effects on an electron beam

Linearly polarized photons at ELSA

Energy Technology Data Exchange (ETDEWEB)

Eberhardt, Holger [Physikalisches Institut, Universitaet Bonn (Germany)

2009-07-01

To investigate the nucleon resonance regime in meson photoproduction, double polarization experiments are currently performed at the electron accelerator ELSA in Bonn. The experiments make use of a polarized target and circularly or linearly polarized photon beams. Linearly polarized photons are produced by coherent bremsstrahlung from an accurately aligned diamond crystal. The orientation of the crystal with respect to the electron beam is measured using the Stonehenge-Technique. Both, the energy of maximum polarization and the plane of polarization, can be deliberately chosen for the experiment. The linearly polarized beam provides the basis for the measurement of azimuthal beam asymmetries, such as {sigma} (unpolarized target) and G (polarized target). These observables are extracted in various single and multiple meson photoproduction channels.

Polarized atomic beams for targets

International Nuclear Information System (INIS)

Grueebler, W.

1984-01-01

The basic principle of the production of polarized atomic hydrogen and deuterium beams are reviewed. The status of the present available polarization, density and intensity are presented. The improvement of atomic beam density by cooling the hydrogen atoms to low velocity is discussed. The possible use of polarized atomic beams as targets in storage rings is shown. It is proposed that polarized atomic beams can be used to produce polarized gas targets with high polarization and greatly improved density

Isolamento , caracterização parcial e atividades biológicas da lectina de entrecasca de aroeira(Schinus terebinthifolius Raddi.)

OpenAIRE

Mary Alves Viana, Ana

2002-01-01

Infusão de entrecasca de Schinus terebinthifolius Raddi., família Anacardiaceae (aroeira), tem sido comumente usada em medicina popular. Lectinas constituem um grupo heterogêneo de proteínas capaz de reconhecer e reversivelmente ligar a carboidratos. O objetivo deste trabalho foi isolar a lectina de entrecasca de S. terebinthifolius e avaliar suas propriedades biológicas. Extrato obtido do pó de entrecasca foi submetido a ensaios de atividade hemaglutinante (AH) usando eritr...

Polarized Proton Collisions at RHIC

CERN Document Server

Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

2005-01-01

The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

Polarization recovery through scattering media.

Science.gov (United States)

de Aguiar, Hilton B; Gigan, Sylvain; Brasselet, Sophie

2017-09-01

The control and use of light polarization in optical sciences and engineering are widespread. Despite remarkable developments in polarization-resolved imaging for life sciences, their transposition to strongly scattering media is currently not possible, because of the inherent depolarization effects arising from multiple scattering. We show an unprecedented phenomenon that opens new possibilities for polarization-resolved microscopy in strongly scattering media: polarization recovery via broadband wavefront shaping. We demonstrate focusing and recovery of the original injected polarization state without using any polarizing optics at the detection. To enable molecular-level structural imaging, an arbitrary rotation of the input polarization does not degrade the quality of the focus. We further exploit the robustness of polarization recovery for structural imaging of biological tissues through scattering media. We retrieve molecular-level organization information of collagen fibers by polarization-resolved second harmonic generation, a topic of wide interest for diagnosis in biomedical optics. Ultimately, the observation of this new phenomenon paves the way for extending current polarization-based methods to strongly scattering environments.

An inter-crystal scatter correction method for DOI PET image reconstruction

International Nuclear Information System (INIS)

Lam, Chih Fung; Hagiwara, Naoki; Obi, Takashi; Yamaguchi, Masahiro; Yamaya, Taiga; Murayama, Hideo

2006-01-01

New positron emission tomography (PET) scanners utilize depth-of-interaction (DOI) information to improve image resolution, particularly at the edge of field-of-view while maintaining high detector sensitivity. However, the inter-crystal scatter (ICS) effect cannot be neglected in DOI scanners due to the use of smaller crystals. ICS is the phenomenon wherein there are multiple scintillations for irradiation of a gamma photon due to Compton scatter in detecting crystals. In the case of ICS, only one scintillation position is approximated for detectors with Anger-type logic calculation. This causes an error in position detection and ICS worsens the image contrast, particularly for smaller hotspots. In this study, we propose to model an ICS probability by using a Monte Carlo simulator. The probability is given as a statistical relationship between the gamma photon first interaction crystal pair and the detected crystal pair. It is then used to improve the system matrix of a statistical image reconstruction algorithm, such as maximum likehood expectation maximization (ML-EM) in order to correct for the position error caused by ICS. We apply the proposed method to simulated data of the jPET-D4, which is a four-layer DOI PET being developed at the National Institute of Radiological Sciences. Our computer simulations show that image contrast is recovered successfully by the proposed method. (author)

Análise da resposta tecidual de dois cimentos endodônticos Analysis of the tissue answer regarding two root canal sealers

Directory of Open Access Journals (Sweden)

Maria Renata Giazzi Nassri

2003-03-01

Full Text Available No presente estudo foram analisados comparativamente dois cimentos endodônticos, Sealapex® e Apexit®, em relação à sua compatibilidade biológica, em tecido subcutâneo. Para tanto, foram utilizados doze ratos, machos, pesando em média 250g, divididos em três grupos, de acordo com o tempo de observação de 7, 21 e 45 dias. Como parte do estudo, foram feitas quatro incisões na região dorsal de cada rato, onde foram implantados quatro tubos de polietileno preenchidos com os cimentos em teste. Decorridos sete, vinte e um e quarenta e cinco dias da cirurgia, os animais foram sacrificados e os tecidos passaram por tramitação laboratorial para obtenção de cortes histológicos corados por hematoxilina-eosina, e posterior análise qualitativa dos resultados. Verificou-se que houve constante atividade macrofágica com o uso dos dois materiais, tendo o cimento Apexit® provocado uma reação tecidual mais agressiva em relação ao cimento Sealapex®, ao mesmo tempo em que, este último, mostrou melhores resultados quando analisadas a intensidade inflamatória provocada e a evolução da reparação tecidual.On the present study, two root canal sealers have been comparatively analysed, Sealapex® and Apexit®, in relation to its biological compatibility to subcutaneous tissue. For this analysis, twelve male rats weighing in average 250 g have been used, divided in three groups, according with its experimental time, 7, 21 and 45 days. Making part of the study, four incisions on the dorsal area of each rat have been made, where were implanted four polyetilene tubes, filled with the testing root canal sealers. After seven, twenty-one and forty-five days of the surgery, the animals have been sacrified and the tissues have been laboratory processed to obtain the histological cut coloured by hematoxilin-eosin, and subsequent quality analysis of the results. From this results, were verified that both sealers caused tissue's intense macrofagic

On feasibility of the experiments with a polarized deuteron beam and a polarized target at Charles University in relation with polarized fusion

International Nuclear Information System (INIS)

Plis, Yu.A.

2001-01-01

There is an interest in the problem of polarized fusion with the neutron-free d 3 He reaction. Up to now, the experimental data on the cross sections of two dd reactions, which produce neutrons at once or through secondary dt reaction, are absent for polarized deuterons. There is a relatively cheap way to carry out the experiments with polarized deuterons at the Charles University in Prague. A polarized deuteron beam with energy from 100 keV up to approximately 1 MeV may be produced on the Van de Graaff accelerator by the channeling of a deuteron beam through magnetized Ni single crystal foil, according M. Kaminsky [Phys. Rev. Lett. 23, 819 (1969)]. This method permits to produce a polarized deuteron beam of an energy ≤1 MeV with a current of ∼1 nA, vector polarization P 3 up to 2/3 and tensor polarization P 33 =0. It will be necessary to modify the existing polarized target at Charles University for work with a low energy deuteron beam [N. S. Borisov et al., Nucl. Instr. and Meth. A 345, 421 (1994)

Polarized particles in storage rings

International Nuclear Information System (INIS)

Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

1977-01-01

Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

Polarized neutron capture in polarized 59Co and 165Ho nuclei

International Nuclear Information System (INIS)

Bosman, J.J.

1976-01-01

Gamma spectroscopy on the reactions 59 Co(n,γ) 60 Co and 165 Ho(n,γ) 166 Ho with polarized neutrons and polarized targets enabled the assignment of spins to 36 levels in 60 Co and 15 levels in 166 Ho. Several of them had not been reported earlier. The techniques used to polarize neutron beams and targets and the gamma-spectroscopy are extensively discussed

Review of polarized ammonium target

International Nuclear Information System (INIS)

Matsuda, Tatsuo

1987-01-01

Recently, ammonia (NH 3 ) and deutron ammonia (ND 3 ), instead of conventional alcohol substances, have been used more frequently as a polarized target substance for experiments of polarization at high energy regions. This article reviews major features of the polarized (deutron) ammonia targets. The dynamic nuclear polarization (DNT) method is widely used in high energy polarization experiments. While only a low polarization degree of hydrogen nucleus of 1.7 percent can be obtained by the Brute force method, DNP can produce polarization as high as ∼ 90 percent (2.5 T, ∼ 200 mK). In 1979, ammonia was irradiated with radiations to form NH 2 free radicals, resulting in the achievement of a high polarization degree of greater than 90 percent (hydrogen). Since then, ammonia and deutron ammonia have increasingly been replacing alcohols including butanol. Irradiation of a target substance with radiations destroys the structure of the substance, leading to a decrease in polarization degree. However, ammonia produces unpaired electrons as a result of irradiation, allowing it to be highly resistant to radiation. This report also present some study results, including observations on effects of radiation on the polarization degree of a target, effects of annealing, and polarization of 14 N. A process for producing an ammonia target is also described. (Nogami, K.)

Achievement of transportable polarized D, in solid HD, with a one day passively maintained polarization

International Nuclear Information System (INIS)

Honig, A.; Alexander, N.; Fan, Q.; Wei, X.; Yu, Y.Y.

1993-01-01

At a previous workshop, we discussed evaporating solid HD with spin-polarized deuterons to produce a high density polarized deuteron gaseous internal target. Since then, we have achieved in solid HD 38% polarized D, whose spin-lattice relaxation time at 1.5 K in a field of 0.1 T is of the order of a day. Optimization of the procedure with the present apparatus should result in 60% D polarization, and longer polarization holding times. The polarized sample of approximately 0.2 cm 3 volume used here is extractable from the dilution refrigerator with a cold-transfer apparatus which maintains the sample at or below 5 K, insuring retention of the high polarization. It is subsequently insertable into a variety of systems, and employable as a polarized solid, liquid, or gas. We are exploring the possibility of extending the polarization maintenance time to about a month (with a matched 1 month preparation time), of polarizing metastably H as well as D, and of producing much larger samples, of the order of 100 cm 3

Acceleration of polarized particles

International Nuclear Information System (INIS)

Buon, J.

1992-05-01

The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

Determination of the polarization states of an arbitrary polarized terahertz beam: vectorial vortex analysis.

Science.gov (United States)

Wakayama, Toshitaka; Higashiguchi, Takeshi; Oikawa, Hiroki; Sakaue, Kazuyuki; Washio, Masakazu; Yonemura, Motoki; Yoshizawa, Toru; Tyo, J Scott; Otani, Yukitoshi

2015-03-24

Vectorial vortex analysis is used to determine the polarization states of an arbitrarily polarized terahertz (0.1-1.6 THz) beam using THz achromatic axially symmetric wave (TAS) plates, which have a phase retardance of Δ = 163° and are made of polytetrafluorethylene. Polarized THz beams are converted into THz vectorial vortex beams with no spatial or wavelength dispersion, and the unknown polarization states of the incident THz beams are reconstructed. The polarization determination is also demonstrated at frequencies of 0.16 and 0.36 THz. The results obtained by solving the inverse source problem agree with the values used in the experiments. This vectorial vortex analysis enables a determination of the polarization states of the incident THz beam from the THz image. The polarization states of the beams are estimated after they pass through the TAS plates. The results validate this new approach to polarization detection for intense THz sources. It could find application in such cutting edge areas of physics as nonlinear THz photonics and plasmon excitation, because TAS plates not only instantaneously elucidate the polarization of an enclosed THz beam but can also passively control THz vectorial vortex beams.

Una perspectiva de los problemas éticos derivada de la investigación biológica: los avatares del evolucionismo

Directory of Open Access Journals (Sweden)

Castrodeza, Carlos

1999-02-01

Full Text Available Not available.En la ciencia actual, el comportamiento ético es una práctica asumida. Es más, la ética como dimensión axiológica del conocimiento está relacionada con otros valores que le colocan al hombre en la cúspide de los seres vivos, confiriéndole así un derecho de uso sobre toda otra forma de vida. Ahora bien, dichos valores son cuestionables en cuanto que no son compatibles con el conocimiento biológico actual. Dicha falta de coherencia se ejemplifica en la influyente obra —en su día y en la actualidad— El Azar y la Necesidad de Jacques Monod. Estas ideas se contrastan con el pensamiento sociobiológico de los últimos tiempos. De este modo, se ilustra y subraya cómo en toda relación biológica mínimamente simbiótica todo ser vivo intenta romper a su favor la relación contractual subyacente mediante el engaño y, asimismo, intenta detectar el engaño potencial en su interlocutor, pretensión que se da tácitamente por supuesta. De manera que la única doctrina ética acorde con el conocimiento bioevolucionista actual sería un «altruismo recíproco vigilado».

Polarized light and optical measurement

CERN Document Server

Clarke, D N; Ter Haar, D

2013-01-01

Polarized Light and Optical Measurement is a five-chapter book that begins with a self-consistent conceptual picture of the phenomenon of polarization. Chapter 2 describes a number of interactions of light and matter used in devising optical elements in polarization studies. Specific optical elements are given in Chapter 3. The last two chapters explore the measurement of the state of polarization and the various roles played in optical instrumentation by polarization and polarization-sensitive elements. This book will provide useful information in this field of interest for research workers,

El derecho a conocer los orígenes biológicos. La necesidad de su reconocimiento para garantizar el derecho a la identidad personal de los adoptados y nacidos por reproducción humana asistida

OpenAIRE

Lorenzi, Mariana de

2015-01-01

[spa] La identidad personal comienza a forjarse en el pasado del ser humano, en sus mismos orígenes biológicos. Desde este axioma, la verdad biológica ha devenido un principio clave del Derecho de Familia occidental. Tradicional paradigma de la filiación por naturaleza, su trascendencia se extiende en la actualidad a los supuestos de filiación adoptiva y por reproducción humana asistida, en gran medida, impulsada por la C.D.N. Este instrumento ha sido esencial, ante todo, para reafirmar el...

Towards helium-3 neutron polarizers

International Nuclear Information System (INIS)

Tasset, F.

1995-01-01

With a large absorption cross-section entirely due to antiparallel spin capture, polarized helium-3 is presently the most promising broad-band polarizer for thermal and epithermal neutrons. Immediate interest was raised amongst the neutron community when a dense gaseous 3 He polarizer was used for the first time in 1988, on a pulsed neutron beam at Los Alamos. With 20 W of laser power on a 30 cm long, 8.6 atm target, 40% 3 He polarization was achieved in a recent polarized electron scattering experiment at SLAC. In this technique the 3 He nuclei are polarized directly at an appropriate high pressure through spin-exchange collisions with a thick, optically pumped rubidium vapor. A different and competitive approach is being presently developed at Mainz University in collaboration with ENS Paris and now the ILL. A discharge is established in pure 3 He at low pressure producing excited metastable atoms which can be optically pumped with infra-red light. Highly effective exchange collision with the atoms remaining in the ground state quickly produces 75% polarization at 1.5 mbar. A truly non-magnetic system then compresses the polarized gas up to several bars as required. The most recent machine comprises a two-stage glass-titanium compressor. In less than 1 h it can inflate a 100 cm 3 target cell with three bars of polarized gas. The very long relaxation times (several days) now being obtained at high pressure with a special metallic coating on the glass walls, the polarized cell can be detached and inserted in the neutron beam as polarizer. We expect 50% 3 He-polarization to be reached soon, allowing such filters to compete favorably with existing Heusler-crystal polarizers at thermal and short neutron wavelengths. It must be stressed that such a system based on a 3 He polarization factory able to feed several passive, transportable, polarizers is well matched to neutron scattering needs. (orig.)

Design of reproducible polarized and non-polarized edge filters using genetic algorithm

International Nuclear Information System (INIS)

Ejigu, Efrem Kebede; Lacquet, B M

2010-01-01

Recent advancement in optical fibre communications technology is partly due to the advancement of optical thin film technology. The advancement of optical thin film technology includes the development of new and existing optical filter design methods. The genetic algorithm is one of the new design methods that show promising results in designing a number of complicated design specifications. It is the finding of this study that the genetic algorithm design method, through its optimization capability, can give more reliable and reproducible designs of any specifications. The design method in this study optimizes the thickness of each layer to get to the best possible solution. Its capability and unavoidable limitations in designing polarized and non-polarized edge filters from absorptive and dispersive materials is well demonstrated. It is also demonstrated that polarized and non-polarized designs from the genetic algorithm are reproducible with great success. This research has accomplished the great task of formulating a computer program using the genetic algorithm in a Matlab environment for the design of a reproducible polarized and non-polarized filters of any sort from any kind of materials

Polarized target as analyzer of polarization of particle beam with spin Ssub(B)=1/2

International Nuclear Information System (INIS)

Golovin, V.M.; Golubeva, M.B.; Gornushkin, Yu.A.

1982-01-01

A possibility of using a polarized target as a target analyzer of beam particle polarization (Ssub(T)=1/2 Psub(T) vector) so that all the components of beam polarization Ssub(B)=1/2 anti Psub(B) should be determined in one experiment, is revealed. A proton polarization target is considered as a polarization target-analyzer. Asub(SK) and Asub(kk) asymmetry tensors are considered for elastic pp and pn scatterings by amplitudes of NN scattering which attain the values of 0.3-0.9 at 95-400 MeV. Asub(kk)(pp) and Asub(sk)(pp) are experimentally measured in the 445-576 MeV range. It is found that their highest absolute values are equal to 0.4-0.5 and 0.2-0.3 respectively. Elastic proton scattering on polarized electrons may be another variant of using polarized target for measuring proton beam polarization. Asub(sk) and Asub(kk) components of asymmetry tensor of elastic pe scattering are graphically presented. A possibility of using a polarized charge with spin I=1/2 as a target-analyzer of particle beam polarization is marked

Condensins under the microscope.

Science.gov (United States)

Maeshima, Kazuhiro; Hibino, Kayo; Hudson, Damien F

2018-04-30

Condensins are key players in mitotic chromosome condensation. Using an elegant combination of state-of-the-art imaging techniques, Walther et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201801048) counted the number of Condensins, examined their behaviors on human mitotic chromosomes, and integrated the quantitative data to propose a new mechanistic model for chromosome condensation. © 2018 Maeshima et al.

Fungos micorrízicos arbusculares em solos da Reserva Biológica Municipal Serra dos Toledos, Itajubá/MG

OpenAIRE

Rogério Melloni; Elisa da Costa Guida; Marielle Rezende de Andrade; Eliane Guimarães Pereira Melloni

2011-01-01

A Reserva Biológica Municipal Serra dos Toledos é um importante remanescente de Mata Atlântica no sul de Minas Gerais, com elevada biodiversidade e riqueza em recursos hídricos. Estudos relacionados à qualidade de solos são necessários em planos de manejo de reservas, os quais objetivam manter ou melhorar a sustentabilidade ambiental dessas áreas. Assim, o objetivo do presente trabalho foi avaliar o potencial de inóculo de fungos micorrízicos arbusculares (MAs) em amostras de solo característ...

Variaciones sobre el modelo psicológico de salud biológica de Ribes: justificación y desarrollo

OpenAIRE

Piña López, Julio Alfonso

2007-01-01

Con base en la propuesta interconductual de Kantor, en este trabajo se presentan algunas variaciones sobre el modelo psicológico de salud biológica de Ribes. Tanto por la lógica que le subyace como por las características de los elementos que lo conforman, se trata de un modelo de campo y multifactorial que pone especial énfasis en la interacción de un conjunto de variables psicológicas de tipo histórico y situacional, que probabilizan la práctica de los comportamientos instrumentales de prev...

Estudio de los factores biológicos del adenocarcinoma de endometrio y su relación con la supervivencia.

OpenAIRE

Bou Serra, José

2008-01-01

RESUMEN Introducción: Los factores pronósticos utilizados en el adenocarcinoma de endometrio para predecir el riesgo de recurrencia son los relacionados con el tipo de tumor (subtipo histológico y grado de diferenciación) y el estadio de diseminación. Otros factores de tipo molecular o biológico se han propuesto por algunos autores como factores pronósticos independientes de recurrencia y muerte por la enfermedad pero sin consenso entre todos los autores. Hipótesis: además de la existencia...

Accidentabilidad laboral con productos biológicos en profesionales sanitarios de Atención Primaria de Guadalajara (1994-2000)

OpenAIRE

J. Cobos López; G. de la Rosa Rodríguez; A. D. Prieto Merino; A. Silva Mato; M. I. Fernández San Martín

2001-01-01

Las infecciones por Virus de la Inmunodeficiencia Humana (VIH),Virus de la Hepatitis B (VHB) y Virus de la Hepatitis C (VHC), de graves consecuencias médicas y sociales, se transmiten por contacto con sangre u otros fluídos orgánicos. El personal sanitario puede infectarse mediante el contacto con fluídos corporales y también transmitir dichas infecciones a los pacientes. Los objetivos de este estudio son conocer la magnitud y distribución de la accidentabilidad laboral con productos biológic...

Estudi de la variabilitat biològica en el posttrasplantament renal optimització del protocol analític assistencial /

OpenAIRE

Biosca i Adzet, Carme

2002-01-01

Consultable des del TDX Títol obtingut de la portada digitalitzada El motiu d'aquesta tesi ha estat trobar indicadors analítics capaços de senyalar canvis significatius en l'estat de salut dels pacients transplantats renals, abans de qualsevol manifestació clínica. En el seguiment de pacients es sol·liciten repetidament proves analítiques al llarg del temps, essent molt important determinar la diferència mínima entre resultats consecutius, d'una mateixa magnitud biològica, que expressen...

Estudo da reatividade química e atividade biológica de biflavonóides isolados da Rheedia gardneriana

OpenAIRE

Verdi, Luiz Gonzaga

2000-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Extração, purificação e identificação de princípios ativos a partir da Rheedia gardneriana (Guttiferae), planta utilizada na medicina popular, principalmente como analgésico e antiinflamatório, com potencial atividade biológica. A partir do extrato hidroalcoólico bruto obtido das folhas, foram realizadas extrações com hexano e acetato de etila. O fracionamento do extrato em acetato de...

Calculation of polarization effects

International Nuclear Information System (INIS)

Chao, A.W.

1983-09-01

Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful

Preliminary Analysis of Chinese GF-3 SAR Quad-Polarization Measurements to Extract Winds in Each Polarization

Directory of Open Access Journals (Sweden)

Lin Ren

2017-11-01

Full Text Available This study analyzed the noise equivalent sigma zero (NESZ and ocean wind sensitivity for Chinese C-band Gaofen-3 (GF-3 quad-polarization synthetic aperture radar (SAR measurements to facilitate further operational wind extraction from GF-3 data. Data from the GF-3 quad-polarization SAR and collocated winds from both NOAA/NCEP Global Forecast System (GFS atmospheric model and National Data Buoy Center (NDBC buoys were used in the analysis. For NESZ, the co-polarization was slightly higher compared to the cross-polarization. Regarding co-polarization and cross-polarization, NESZ was close to RadarSAT-2 and Sentinel-1 A. Wind sensitivity was analyzed by evaluating the dependence on winds in terms of normalized radar cross-sections (NRCS and polarization combinations. The closest geophysical model function (GMF and the polarization ratio (PR model to GF-3 data were determined by comparing data and the model results. The dependence of co-polarized NRCS on wind speed and azimuth angle was consistent with the proposed GMF models. The combination of CMOD5 and CMOD5.N was considered to be the closest GMF in co-polarization. The cross-polarized NRCS exhibited a strong linear relationship with moderate wind speeds higher than 4 m·s−1, but a weak correlation with the azimuth angle. The proposed model was considered as the closest GMF in cross-polarization. For polarization combinations, PR and polarization difference (PD were considered. PR increased only with the incidence angle, whereas PD increased with wind speed and varied with azimuth angle. There were three very close PR models and each can be considered as the closest. Preliminary results indicate that GF-3 quad-polarization data are valid and have the ability to extract winds in each polarization.

[Intermediate energy studies of polarization transfer, polarized deuteron scattering, and (p,π+-) reactions: Rapporteur's report

International Nuclear Information System (INIS)

Moss, J.M.

1985-01-01

An overview of intermediate energy (80 to 1000 MeV) study contributions to the International Polarization Symposium in Osaka, Japan, August 1985 is presented in this report. Contributions fall into three categories: polarization transfer, polarized deuteron scattering and polarized (p,π +- ) reactions

Enhancement of molecular NMR signal induced by polarization transfer from laser-polarized 129Xe

International Nuclear Information System (INIS)

Sun Xianping

2001-01-01

There is a large non-equilibrium nuclear polarization and a longer relaxation time in the laser-polarized 129 Xe produced by means of optical pumping and spin exchange. The characteristics of the laser-polarized 129 Xe permit the transfer of the polarization to enhance the atomic nuclear spin in liquid, solid and surface of solid molecules. Therefore, the sensitivity in nuclear magnetic resonance measurements for the molecules is enhanced and applications in the investigations of materials and surface sciences are expanded. The progress in the investigations of materials and surface sciences are expanded. The progress in the investigations of the polarization transfer between laser-polarized 129 Xe and the atomic nuclei in the molecules, the relative physics and the measurement of some parameters are introduced

Graphics of polar figure; Graficado de figura polar

Energy Technology Data Exchange (ETDEWEB)

Macias B, L.R

1991-11-15

The objective of this work, is that starting from a data file coming from a spectra that has been softened, and of the one that have been generated its coordinates to project it in stereographic form, to create the corresponding polar figure making use of the Cyber computer of the ININ by means of the GRAPHOS package. This work only requires a Beta, Fi and Intensity (I) enter data file. It starts of the existence of a softened spectra of which have been generated already with these data, making use of some language that in this case was FORTRAN for the Cyber computer, a program is generated supported in the Graphos package that allows starting of a reading of the Beta, Fi, I file, to generate the points in a stereographic projection and that it culminates with the graph of the corresponding polar figure. The program will request the pertinent information that is wanted to capture in the polar figure just as: date, name of the enter file, indexes of the polar figure, number of levels, radio of the stereographic projection (cms.), crystalline system to which belongs the sample, name the neuter graph file by create and to add the own general data. (Author)

Airborne Laser Polarization Sensor

Science.gov (United States)

Kalshoven, James, Jr.; Dabney, Philip

1991-01-01

Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

Polarization-preserving holey fibers

DEFF Research Database (Denmark)

Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou

2001-01-01

In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization......In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...

Development of polarized {sup 3}He filter for polarized neutron experiment

Energy Technology Data Exchange (ETDEWEB)

Sakai, K.; Sato, H.; Yoshimi, A.; Asahi, K. [Tokyo Inst. of Tech. (Japan). Faculty of Science; Masuda, Y.; Muto, S.; Ishimoto, S.; Morimoto, K.

1996-08-01

A high-pressure polarized {sup 3}He gas cell, pumped with two diode lasers, has been developed at KEK for use as a polarizer and a spin analyzer for low energy neutrons. The polarization attained of {sup 3}He was determined through the measurement of the transmission of the unpolarized neutrons through the {sup 3}He cell. So far we obtained P{sub He}=18% at 10 atm and P{sub He}=12% at 20 atm. (author)

Thermal stability study of Cr/Au contact formed on n-type Ga-polar GaN, N-polar GaN, and wet-etched N-polar GaN surfaces

International Nuclear Information System (INIS)

Choi, Yunju; Kim, Yangsoo; Ahn, Kwang-Soon; Kim, Hyunsoo

2014-01-01

Highlights: • The Cr/Au contact on n-type Ga-polar (0 0 0 1) GaN, N-polar (0 0 0 −1) GaN, and wet-etched N-polar GaN were investigated. • Thermal annealing led to a significant degradation of contact formed on N-polar n-GaN samples. • Contact degradation was shown to be closely related to the increase in the electrical resistivity of n-GaN. • Out-diffusion of Ga and N atoms was clearly observed in N-polar samples. - Abstract: The electrical characteristics and thermal stability of a Cr/Au contact formed on n-type Ga-polar (0 0 0 1) GaN, N-polar GaN, and wet-etched N-polar GaN were investigated. As-deposited Cr/Au showed a nearly ohmic contact behavior for all samples, i.e., the specific contact resistance was 3.2 × 10 −3 , 4.3 × 10 −4 , and 1.1 × 10 −3 Ω cm 2 for the Ga-polar, flat N-polar, and roughened N-polar samples, respectively. However, thermal annealing performed at 250 °C for 1 min in a N 2 ambient led to a significant degradation of contact, i.e., the contact resistance increased by 186, 3260, and 2030% after annealing for Ga-polar, flat N-polar, and roughened N-polar samples, respectively. This could be due to the different disruption degree of Cr/Au and GaN interface after annealing, i.e., the insignificant interfacial reaction occurred in the Ga-polar sample, while out-diffusion of Ga and N atoms was clearly observed in N-polar samples

Thermal stability study of Cr/Au contact formed on n-type Ga-polar GaN, N-polar GaN, and wet-etched N-polar GaN surfaces

Energy Technology Data Exchange (ETDEWEB)

Choi, Yunju [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Kim, Yangsoo [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Ahn, Kwang-Soon, E-mail: kstheory@ynu.ac.kr [School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of); Kim, Hyunsoo, E-mail: hskim7@jbnu.ac.kr [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

2014-10-30

Highlights: • The Cr/Au contact on n-type Ga-polar (0 0 0 1) GaN, N-polar (0 0 0 −1) GaN, and wet-etched N-polar GaN were investigated. • Thermal annealing led to a significant degradation of contact formed on N-polar n-GaN samples. • Contact degradation was shown to be closely related to the increase in the electrical resistivity of n-GaN. • Out-diffusion of Ga and N atoms was clearly observed in N-polar samples. - Abstract: The electrical characteristics and thermal stability of a Cr/Au contact formed on n-type Ga-polar (0 0 0 1) GaN, N-polar GaN, and wet-etched N-polar GaN were investigated. As-deposited Cr/Au showed a nearly ohmic contact behavior for all samples, i.e., the specific contact resistance was 3.2 × 10{sup −3}, 4.3 × 10{sup −4}, and 1.1 × 10{sup −3} Ω cm{sup 2} for the Ga-polar, flat N-polar, and roughened N-polar samples, respectively. However, thermal annealing performed at 250 °C for 1 min in a N{sub 2} ambient led to a significant degradation of contact, i.e., the contact resistance increased by 186, 3260, and 2030% after annealing for Ga-polar, flat N-polar, and roughened N-polar samples, respectively. This could be due to the different disruption degree of Cr/Au and GaN interface after annealing, i.e., the insignificant interfacial reaction occurred in the Ga-polar sample, while out-diffusion of Ga and N atoms was clearly observed in N-polar samples.

Polarized proton colliders

International Nuclear Information System (INIS)

Roser, T.

1995-01-01

High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

Polar localization of plasma membrane Ca2+/Mg2+ ATPase correlates with the pattern of steady ionic currents in eggs ofLymnaea stagnalis andBithynia tentaculata (Mollusca).

Science.gov (United States)

Zivkovic, Danica; Créton, Robbert; Zwaan, Gideon; de Bruijn, Willem C; Dohmen, M René

1990-11-01

During extrusion of the first polar body in eggs ofLymnaea stagnalis andBithynia tentaculata a localized Ca 2+ /Mg 2+ ATPase activity was detected, using Ando's enzyme-cytochemical method for electron microscopy [Ando et al. (1981) Acta Histochem Cytochem 14:705-726]. The enzyme activity was distributed in a polar fashion, along the cytoplasmic face of the plasma membrane. In the eggs ofLymnaea it was found only in the vegetal hemisphere, whereas inBithynia eggs it was localized both in the vegetal hemisphere and at the animal pole. This pattern of enzyme activity corresponds to the polar pattern of transcellular ionic currents measured with the vibrating probe, which we showed to be partially carried or regulated by calcium [Zivkovic and Dohmen (1989) Biol Bull (Woods Hole) 176 (Suppl):103-109]. The characteristics of the ATPase were studied using a variety of approaches such as ion and substrate depletions and substitutions, addition of specific inhibitors of ATPase activity, treatment with EDTA/EGTA and electron energy-loss spectrometry. The results indicate that, inLymnaea, there are at least two enzymatic entities. The first one is a Ca 2+ /Mg 2+ ATPase localized along the membrane and in the cortex of the vegetal hemisphere. The second one is a Ca 2+ -stimulated ATPase (calcium pump of the plasma membrane) localized in a small region of the membrane at the vegetal pole. We speculate that in the eggs ofLymnaea andBithynia a functional relationship exists between the plasma-membrane-associated ATPase activity and the transcellular ionic currents measured in the same region.

Polarization and Persuasion: Integrating the Elaboration Likelihood Model with Explanations of Group Polarization.

Science.gov (United States)

Mongeau, Paul A.

Interest has recently focused on group polarization as a function of attitude processes. Several recent reviewers have challenged polarization researchers to integrate the explanations of polarization to existing theories of attitude change. This review suggests that there exists a clear similarity between the social comparison and persuasive…

Polar bears at risk

Energy Technology Data Exchange (ETDEWEB)

Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

2002-05-01

Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

Asymptotic behaviour in polarized and half-polarized U(1) symmetric vacuum spacetimes

International Nuclear Information System (INIS)

Isenberg, James; Moncrief, Vincent

2002-01-01

We use the Fuchsian algorithm to study the behaviour near the singularity of certain families of U(1) symmetric solutions of the vacuum Einstein equations (with the U(1) isometry group acting spatially). We consider an analytic family of polarized solutions with the maximum number of arbitrary functions consistent with the polarization condition (one of the 'gravitational degrees of freedom' is turned off) and show that all members of this family are asymptotically velocity term dominated (AVTD) as one approaches the singularity. We show that the same AVTD behaviour holds for a family of 'half-polarized' solutions, which is defined by adding one extra arbitrary function to those characterizing the polarized solutions. (The full set of nonpolarized solutions involves two extra arbitrary functions.) Using SL(2, R) Geroch transformations, we produce a further class of U(1) symmetric solutions with AVTD behaviour. We begin to address the issue of whether AVTD behaviour is independent of the choice of time foliation by showing that indeed AVTD behaviour is seen for a wide class of choices of harmonic time in the polarized and half-polarized (U(1) symmetric vacuum) solutions discussed here

The polarization of fast neutrons

International Nuclear Information System (INIS)

Talov, V.V.

2000-01-01

The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li(p,n) 7 Be, and T(p,n) 3 He reactions. (authors)

Elite Polarization and Public Opinion

DEFF Research Database (Denmark)

Robison, Joshua; Mullinix, Kevin

2016-01-01

Elite polarization has reshaped American politics and is an increasingly salient aspect of news coverage within the United States. As a consequence, a burgeoning body of research attempts to unravel the effects of elite polarization on the mass public. However, we know very little about how...... polarization is communicated to the public by news media. We report the results of one of the first content analyses to delve into the nature of news coverage of elite polarization. We show that such coverage is predominantly critical of polarization. Moreover, we show that unlike coverage of politics focused...... on individual politicians, coverage of elite polarization principally frames partisan divisions as rooted in the values of the parties rather than strategic concerns. We build on these novel findings with two survey experiments exploring the influence of these features of polarization news coverage on public...

FDTD simulation of trapping nanowires with linearly polarized and radially polarized optical tweezers.

Science.gov (United States)

Li, Jing; Wu, Xiaoping

2011-10-10

In this paper a model of the trapping force on nanowires is built by three dimensional finite-difference time-domain (FDTD) and Maxwell stress tensor methods, and the tightly focused laser beam is expressed by spherical vector wave functions (VSWFs). The trapping capacities on nanoscale-diameter nanowires are discussed in terms of a strongly focused linearly polarized beam and radially polarized beam. Simulation results demonstrate that the radially polarized beam has higher trapping efficiency on nanowires with higher refractive indices than linearly polarized beam.

Avaliação do tratamento biológico de lixiviado de aterro sanitário em escala real na Região Sul do Brasil

Directory of Open Access Journals (Sweden)

Iracema Souza Maia

2015-12-01

Full Text Available RESUMO Esta pesquisa avaliou o desempenho do sistema de tratamento biológico de lixiviado de um aterro sanitário em escala real formado por duas lagoas anaeróbias (LAs operadas em série, um sistema de lodos ativados (SLOA e uma lagoa facultativa (LF. O objetivo do estudo foi avaliar a eficiência desse sistema biológico por meio do monitoramento de variáveis físico-químicas e ensaios de toxicidade, já que existe carência de artigos científicos para estudos em escala real e para esse tipo de configuração no tratamento de lixiviados. As coletas foram realizadas com frequência quinzenal, seguidas de análises laboratoriais para caracterização dos diferentes lixiviados coletados ao longo do tratamento. A eficiência de remoção de matéria orgânica observada foi de 80 e 60% para carbono orgânico dissolvido e demanda química de oxigênio, respectivamente. O sistema apresentou ainda eficiência de 83 e 73% para remoção de nitrogênio amoniacal e fósforo, respectivamente. Observou-se uma diminuição média de 44% de toxicidade do lixiviado tratado, que apresentou características tóxicas para o organismo teste Daphnia magna . A configuração do sistema biológico demonstrou-se vantajosa na remoção de matéria orgânica e fração nitrogenada, contudo os resultados indicam a necessidade de tratamento complementar.

Accidentes biológicos en estudiantes de Medicina de la Universidad Industrial de Santander, Bucaramanga, Colombia Biological accidents among Medical students from Universidad Industrial de Santander, Bucaramanga, Colombia

Directory of Open Access Journals (Sweden)

Luis Felipe Tapias-Vargas

2010-12-01

Full Text Available Introducción: Los accidentes biológicos representan un riesgo ocupacional significativo para los trabajadores de la salud, y para los estudiantes de medicina. Objetivo: Establecer la prevalencia de accidentes biológicos y los factores y comportamientos asociados en la población de estudiantes de medicina. Materiales y métodos: Se encuestaron los estudiantes de medicina del área clínica de la Universidad Industrial de Santander. El instrumento de encuesta preguntaba sobre utilización de elementos de protección, caracterización y comportamientos asociados al último accidente biológico sufrido. La información obtenida fue analizada mediante porcentajes y promedios. Para evaluar los factores asociados al accidente se calcularon Razones de Prevalencia y sus IC 95%. Resultados: Se encuestaron 330 estudiantes. El uso rutinario de guantes se reportó en un 99,3%, de doble guante en 13,9%, tapabocas en 77,4% y de gafas en 30,7%. La prevalencia de accidentes biológicos fue de 18%, la cual aumentaba de acuerdo al año de estudio. El accidente no fue reportado en 48% de los casos. Se encontró una asociación positiva entre el sufrimiento de al menos un accidente biológico durante lo cursado de la carrera y el uso completo de medidas de protección en tercer y cuarto año, RP=2,92 (IC 95% 0,95 - 8,93; y negativa para quinto y sexto año, RP=0,84 (IC 95% 0,50-1,41, p=0,0479. Conclusión: Los accidentes biológicos son frecuentes en nuestros estudiantes de medicina. Se debe insistir desde los primeros semestres en la importancia del uso de elementos de protección, el reporte del accidente y los protocolos postexposición. Salud UIS 2010; 42: 192-199Introduction: Biological accidents represent a significant occupational risk to healthcare workers including medical students. Objective: To establish the prevalence of biological accidents, and its associated factors and behaviors among medical students. Materiales and methods: Medical students in

Solución numérica de modelos biológicos de reacción difusión en dominios fijos mediante el método de los elementos finitos

Directory of Open Access Journals (Sweden)

Libardo Andrés González

2009-01-01

Full Text Available Múltiples fenómenos biológicos se han descrito mediante modelos matemáticos formulados a partir de ecuaciones de reacción difusión. La solución de este tipo de ecuaciones da lugar a la formación de patrones espacio-temporales que se ajustan a la realidad biológica del fenómeno modelado. En este artículo se describe la implementación numérica de tres modelos de reacción difusión bien referenciados: el modelo de morfogénesis de Schnakenberg, y los modelos de reacción cinética de Gierer-Meinhardt y Thomas. El objetivo es analizar el conjunto de parámetros asociados con la formación de los patrones espaciotemporales. La implementación numérica se realiza utilizando el método de los elementos finitos en dominios unidimensionales y bidimensionales. Se concluye que la formación de patrones espacio-temporales en modelos de reacción difusión depende de los parámetros constantes del modelo, de las condiciones iniciales y de la técnica de implementación. El análisis de estas dependencias es útil para la formulación y validación de nuevos modelos matemáticos que describan fenómenos biológicos.

Polarization Property Measurement of the Long Undulator Radiation Using Cr/C Multilayer Polarization Elements

International Nuclear Information System (INIS)

Niibe, Masahito; Mukai, Mikihito; Shoji, Yoshihiko; Kimura, Hiroaki

2004-01-01

A rotating analyzer ellipsometry (RAE) system was developed with Cr/C multilayers that function as polarization elements for photon energy range of 110 - 280 eV. Polarization properties of a planar undulator change axisymmetrically in off-axial manner, and the second harmonic is more remarkable for the change. By using the RAE system, the polarization property of the second harmonic radiation from the NewSUBARU long undulator at the energy of 180 eV was examined. The degree of linear polarization of the on-axis radiation was over 0.996. The spatial distribution of the polarization azimuth was measured and was in fair agreement with the theoretical calculation. A peculiar behavior of the polarization property near the radiation peak of the second harmonic was observed by changing the height of the undulator gap

PolarTREC: Successful Methods and Tools for Attaining Broad Educational Impacts with Interdisciplinary Polar Science

Science.gov (United States)

Timm, K. M.; Warburton, J.; Owens, R.; Warnick, W. K.

2008-12-01

PolarTREC--Teachers and Researchers Exploring and Collaborating, a program of the Arctic Research Consortium of the U.S. (ARCUS), is a National Science Foundation (NSF)-funded International Polar Year (IPY) project in which K-12 educators participate in hands-on field experiences in the polar regions, working closely with IPY scientists as a pathway to improving science education. Developing long-term teacher- researcher collaborations through PolarTREC ensures up-to-date climate change science content will permeate the K-12 education system long after the IPY. By infusing education with the cutting edge science from the polar regions, PolarTREC has already shown an increase in student and public knowledge of and interest in the polar regions and global climate change. Preliminary evaluations have shown that PolarTREC's program activities have many positive impacts on educators and their ability to teach science concepts and improve their teaching methods. Additionally, K-12 students polled in interest surveys showed significant changes regarding the importance of understanding the polar regions as a person in today's world. Researchers have been overwhelmingly satisfied with PolarTREC and cited several specific strengths, including the program's crucial link between the teachers' field research experiences and their classroom and the extensive training provided to teachers prior to their expedition. This presentation will focus on other successful components of the PolarTREC program and how researchers and organizations might use these tools to reach out to the public for long-term impacts. Best practices include strategies for working with educators and the development of an internet-based platform for teachers and researchers to interact with the public, combining several communication tools such as online journals and forums, real-time Internet seminars, lesson plans, activities, audio, and other educational resources that address a broad range of scientific

Claritromicina associada com pirímetamina na toxoplasmose cerebral - relato de dois casos

Directory of Open Access Journals (Sweden)

Marcos Olivicr Dalston

1995-12-01

Full Text Available Os autores relatam a resposta terapêutica da claritromicina associada com pirímetamina em dois casos de toxoplasmose cerebral ocorridos em pacientes com Síndrome de Imunodeficiência Adquirida (SIDA. Nos dois casos o diagnóstico foi presuntivo, baseando-se nas manifestações clínicas e na presença de lesões expansivas hipercaptantes detectadas na tomografia computadorizada (TC de crânio. Em ambos os casos, observou-se exantema com o uso da sulfadiazina e da clindamicina, razão pela qual tais medicamentos foram substituídos pela claritromicina (1,5 a 2g/dia associada à pirímetamina (25mg/dia. A resposta terapêutica foi favorável nos dois casos com melhora das manifestações neurológicas e dos achados neurorradiológicos. Os autores sugerem que a associação claritromicina com pirímetamina pode ser útil como opção terapêutica na toxoplasmose cerebral em pacientes com SIDA que apresentam intolerância ou outra contra-indicação ao emprego das sulfonamidas.

Aspectos jurídico internacionales del acceso a los recursos genéticos que componen la diversidad biológica

OpenAIRE

Rodrigues Bertoldi, Márcia

2003-01-01

Actualmente nos encontramos en un momento de profunda transformación en la historia de la humanidad y de las leyes de la naturaleza caracterizada, entre otras cosas, por un desarrollo expansivo de la industria biotecnológica. La biotecnología tiene como materia prima los recursos genéticos y, también, los extractos bioquímicos de las especies vegetales, animales y microbianas que componen la diversidad biológica, la cual permite un sin fin de posibilidades alimenticias, medicinales, energétic...

Redução química e biológica do cromo hexavalente aplicado ao solo

Directory of Open Access Journals (Sweden)

D. D. Castilhos

2001-06-01

Full Text Available Realizou-se um experimento em laboratório, com o objetivo de avaliar não só a redução do cromo hexavalente aplicado ao solo com ênfase ao efeito da aplicação de carbono orgânico, manganês divalente, mas também a participação da microbiota do solo. Utilizaram-se, como unidades experimentais, amostras de 50 g de um Argissolo, acondicionadas em sacos de polipropileno e incubadas durante 42 dias com calcário para elevar o pH a 6,0 (2,0 t ha-1 de CaCO3 + MgCO3 na proporção de 2:1, Cr6+, esterco bovino e Mn2+ nas doses de 20, 50 e 40 mg kg-1, respectivamente. Metade das amostras foi sujeita à esterilização por autoclavagem com o objetivo de eliminar a atividade biológica. A aplicação de esterco bovino e sulfato de manganês promoveu a total redução do cromo hexavalente para cromo trivalente (Cr6+ → Cr3+ no solo, em 42 dias. Os modelos, quadrático e exponencial, foram os que melhor descreveram a cinética de redução com o tempo. A redução do Cr6+ foi estimulada pela atividade microbiana, sendo 16% maior em amostras de solo não esterilizadas, que continham esterco bovino, em comparação com as mesmas amostras esterilizadas por autoclavagem. Os resultados demonstraram que a descontaminação do solo que contém teores tóxicos de Cr6+ pode ser viabilizada tanto pela incorporação de adubo orgânico como pela manutenção de sua atividade biológica.

Factores de riesgo para el desarrollo psicomotor en lactantes nacidos en óptimas condiciones biológicas

Directory of Open Access Journals (Sweden)

Isidora de Andraca

1998-04-01

Full Text Available OBJECTIVO: Evaluar el efecto de factores de riesgo para el desarrollo infantil en niños, de nivel socioeconómico bajo, nacidos en óptimas condiciones biológicas pero expuestos a condiciones sociales adversas. METODOLOGÍA: Lactantes de ambos sexos em número de 788, fueron exhaustivamente estudiados en términos de: alimentación, crecimiento, ambiente físico y psicosocial. Se controlaron prospectivamente hasta los 12 meses de edad, momento en que se evaluó el desarrollo mental (MDI y motor (PDI a través de la escala de Bayley. A partir de las variables medidas se identificó 18 factores de riesgo, los que fueron dicotomizados (bajo y alto riesgo. RESULTADOS: Lactancia materna, temperamento del niño, inteligencia materna y estimulación en el hogar se asocian consistentemente con MDI y PDI. Luego de ajustar por covariables, la estimulación en el hogar persiste como factor significativo en la explicación de la variabilidad del MDI y PDI, en tanto que el sexo del niño se consolida como factor condicionante del desarrollo motor. El efecto acumulado de 7 o más factores de riesgo se asocia con una disminución significativa de los puntajes de desarrollo. La combinación de categorías de riesgo de temperamento infantil, inteligencia materna, rol del padre y estimulación en el hogar alcanza mejor predicción del desarrollo infantil que otras combinaciones puestas a prueba en este estudio. CONCLUSIONE: Se concluye que, aún en niños biológicamente indemnes, el desarrollo psicomotor se afecta negativamente ante la presencia de condiciones ambientales adversas que actúan simultáneamente.

Factores de riesgo para el desarrollo psicomotor en lactantes nacidos en óptimas condiciones biológicas

Directory of Open Access Journals (Sweden)

Andraca Isidora de

1998-01-01

Full Text Available OBJECTIVO: Evaluar el efecto de factores de riesgo para el desarrollo infantil en niños, de nivel socioeconómico bajo, nacidos en óptimas condiciones biológicas pero expuestos a condiciones sociales adversas. METODOLOGÍA: Lactantes de ambos sexos em número de 788, fueron exhaustivamente estudiados en términos de: alimentación, crecimiento, ambiente físico y psicosocial. Se controlaron prospectivamente hasta los 12 meses de edad, momento en que se evaluó el desarrollo mental (MDI y motor (PDI a través de la escala de Bayley. A partir de las variables medidas se identificó 18 factores de riesgo, los que fueron dicotomizados (bajo y alto riesgo. RESULTADOS: Lactancia materna, temperamento del niño, inteligencia materna y estimulación en el hogar se asocian consistentemente con MDI y PDI. Luego de ajustar por covariables, la estimulación en el hogar persiste como factor significativo en la explicación de la variabilidad del MDI y PDI, en tanto que el sexo del niño se consolida como factor condicionante del desarrollo motor. El efecto acumulado de 7 o más factores de riesgo se asocia con una disminución significativa de los puntajes de desarrollo. La combinación de categorías de riesgo de temperamento infantil, inteligencia materna, rol del padre y estimulación en el hogar alcanza mejor predicción del desarrollo infantil que otras combinaciones puestas a prueba en este estudio. CONCLUSIONE: Se concluye que, aún en niños biológicamente indemnes, el desarrollo psicomotor se afecta negativamente ante la presencia de condiciones ambientales adversas que actúan simultáneamente.

Dynamics of Venus' Southern hemisphere and South Polar Vortex from VIRTIS data obtained during the Venus Expres Mission

Science.gov (United States)

Hueso, R.; Garate-Lopez, I.; Sanchez-Lavega, A.

2011-12-01

The VIRTIS instrument onboard Venus Express observes Venus in two channels (visible and infrared) obtaining spectra and multi-wavelength images of the planet. The images have been used to trace the motions of the atmosphere at different layers of clouds [1-3]. We review the VIRTIS cloud image data and wind results obtained by different groups [1-3] and we present new results concerning the morphology and evolution of the South Polar Vortex at the upper and lower cloud levels with data covering the first 900 days of the mission. We present wind measurements of the South hemisphere obtained by cloud tracking individual cloud features and higher-resolution wind results of the polar region covering the evolution of the South polar vortex. The later were obtained by an image correlation algorithm run under human supervision to validate the data. We present day-side data of the upper clouds obtained at 380 and 980 nm sensitive to altitudes of 66-70 km, night-side data in the near infrared at 1.74 microns of the lower cloud (45-50 km) and day and night-side data obtained in the thermal infrared (wavelengths of 3.8 and 5.1 microns) which covers the dynamical evolution of Venus South Polar vortex at the cloud tops (66-70 km). We explore the different dynamics associated to the varying morphology of the vortex, its dynamical structure at different altitudes, the variability of the global wind data of the southern hemisphere and the interrelation of the polar vortex dynamics with the wind dynamics at subpolar and mid-latitudes. Acknowledgements: Work funded by Spanish MICIIN AYA2009-10701 with FEDER support and Grupos Gobierno Vasco IT-464-07. References [1] A. Sánchez-Lavega et al., Geophys. Res. Lett. 35, L13204, (2008). [2] D. Luz et al., Science, 332, 577-580 (2011). [3] R. Hueso, et al., Icarus doi:10.1016/j.icarus.2011.04.020 (2011)

The evolution of tensor polarization

International Nuclear Information System (INIS)

Huang, H.; Lee, S.Y.; Ratner, L.

1993-01-01

By using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization, the spin transfer matrix for spin tensor polarization is derived. The evolution equation for the tensor polarization is studied in the presence of an isolate spin resonance and in the presence of a spin rotor, or snake

System for measuring of proton polarization in polarized target

International Nuclear Information System (INIS)

Derkach, A.Ya.; Lukhanin, A.A.; Karnaukhov, I.M.; Kuz'menko, V.S.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

1981-01-01

Measurement system of proton polarization in the target, which uses the method of nuclear magnetic resonance is described. To record the signal of NMR-absorption a parallel Q-meter of voltage with analogous subtraction of resonance characteristics of measurement circuit is used. To obtain gradual sensitivity of the system to polarization state in the whole volume of the target the measurement coils is made of tape conductor. The analysis and mathematical modelling of Q-meter are carried out. Corrections for nonlinearity and dispersion are calculated. Key diagrams of the main electron blocks of Q-meter are presented. The system described operates on line with the M6000 computer. Total error of measurement of polarization value of free protons in the target does not exceed 6% [ru

Polarization experiments

International Nuclear Information System (INIS)

Halzen, F.

1977-02-01

In a theoretical review of polarization experiments two important points are emphasized: (a) their versatility and their relevance to a large variety of aspects of hadron physics (tests of basic symmetries; a probe of strong interaction dynamics; a tool for hadron spectroscopy); (b) the wealth of experimental data on polarization parameters in pp and np scattering in the Regge language and in the diffraction language. (author)

Study of Jupiter polarization properties

International Nuclear Information System (INIS)

Bolkvadze, O.R.

1980-01-01

Investigations into polarization properties of the Jupiter reflected light were carried on at the Abastumani astrophysical observatory in 1967, 1968 and 1969 in the four spectral ranges: 4000, 4800, 5400 and 6600 A deg. Data on light polarization in different parts of the Jupiter visible disk are given. Curves of dependence of the planet light polarization degree on a phase angle are plotted. It is shown that in the central part of the visible planet disk the polarization degree is low. Atmosphere is in a stable state in this part of Jupiter. Mean radius of particles of a cloud layer is equal to 0.26μ, and optical thickness of overcloud atmosphere tau=0.05. Height of transition boundary of the cloud layer into overcloud gas atmosphere changes from year to year at the edges of the equatorial zone. Optical thickness of overcloud atmosphere changes also with changing height of a transient layer. The polar Jupiter regions possess a high degree of polarization which depends on a latitude. Polarization increases monotonously with the latitude and over polar regions accepts a maximum value [ru

High energy polarized electron beams

International Nuclear Information System (INIS)

Rossmanith, R.

1987-01-01

In nearly all high energy electron storage rings the effect of beam polarization by synchrotron radiation has been measured. The buildup time for polarization in storage rings is of the order of 10 6 to 10 7 revolutions; the spins must remain aligned over this time in order to avoid depolarization. Even extremely small spin deviations per revolution can add up and cause depolarization. The injection and the acceleration of polarized electrons in linacs is much easier. Although some improvements are still necessary, reliable polarized electron sources with sufficiently high intensity and polarization are available. With the linac-type machines SLC at Stanford and CEBAF in Virginia, experiments with polarized electrons will be possible

Alimentação complementar e características maternas de crianças menores de dois anos de idade em Florianópolis (SC Complementary feeding and maternal characteristics of children younger than two years old in Florianópolis, Santa Catarina, Brazil

Directory of Open Access Journals (Sweden)

Elizabeth Nappi Corrêa

2009-09-01

Full Text Available OBJETIVO: Verificar a associação entre o período de introdução de alimentos complementares e características socioeconômicas maternas e biológicas de crianças menores de dois anos de idade. MÉTODOS: Estudo transversal com 516 mães de crianças com menos de dois anos de idade entrevistadas no dia da Campanha Nacional de Vacinação em Unidades de Saúde de 2004 na cidade de Florianópolis (SC. Foram coletados dados sobre a época de introdução de alimentos complementares e características socioeconômicas maternas e biológicas da criança. A análise de regressão logística múltipla foi aplicada para verificar a associação da introdução de cada tipo de alimento com as características estudadas. RESULTADOS: Constatou-se que, dentre as crianças menores de dois anos de idade, apenas 28,7% haviam recebido aleitamento materno exclusivo até os seis meses e, dentre as crianças que estavam com menos de seis meses no momento da pesquisa, apenas 49,6% estavam recebendo aleitamento materno exclusivo. Observou-se, ainda, que 80% das crianças receberam fruta, 77,5% receberam suco natural associados ao aleitamento materno e 36,8% receberam leite modificado, em substituição ao aleitamento materno, antes de completarem seis meses de idade. A análise de regressão multivariada identificou que as mães com menor grau de escolaridade e que trabalhavam fora de casa apresentaram mais chance de introduzir precocemente alimentos aos seus filhos. CONCLUSÕES: Baixa escolaridade materna e atividade fora do lar se associaram à introdução precoce de alimentos.OBJECTIVE: In children younger than two years old, to verify the association between complementary food introduction, socioeconomic characteristics of mothers and biological characteristics of children. METHODS: Cross-sectional study of 516 mothers of children younger than two years old who were interviewed during 2004 national campaign for vaccination in health care clinics of Florian

Interferometric polarization control

International Nuclear Information System (INIS)

Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey; Novak, Giles

2006-01-01

We develop the Jones and Mueller matrices for structures that allow control of the path length difference between two linear orthogonal polarizations and consider the effect of placing multiple devices in series. Specifically, we find that full polarization modulation (measurement of Stokes Q, U, and V) can be achieved by placing two such modulators in series if the relative angles of the beam-splitting grids with respect to the analyzer orientation are appropriately chosen. Such a device has several potential advantages over a spinning wave plate modulator for measuring astronomical polarization in the far infrared through millimeter: (i) The use of small, linear motions eliminates the need for cryogenic rotational bearings; (ii) the phase flexibility allows measurement of circular as well as linear polarization; and (iii) this architecture allows for both multiwavelength and broadband modulation. We also present initial laboratory results

Photonic Crystal Polarizing and Non-Polarizing Beam Splitters

International Nuclear Information System (INIS)

Chun-Ying, Guan; Jin-Hui, Shi; Li-Boo, Yuan

2008-01-01

A polarizing beam splitter (PBS) and a non-polarizing beam splitter (NPBS) based on a photonic crystal (PC) directional coupler are demonstrated. The photonic crystal directional coupler consists of a hexagonal lattice of dielectric pillars in air and has a complete photonic band gap. The photonic band structure and the band gap map are calculated using the plane wave expansion (PWE) method. The splitting properties of the splitter are investigated numerically using the finite difference time domain (FDTD) method

Polarity-sensitive nanocarrier for oral delivery of Sb(V and treatment of cutaneous leishmaniasis

Directory of Open Access Journals (Sweden)

Lanza JS

2016-05-01

Full Text Available Juliane S Lanza,1 Flaviana R Fernandes,1 José D Corrêa-Júnior,2 José MC Vilela,3 Rogério Magalhães-Paniago,4 Lucas AM Ferreira,5 Margareth S Andrade,3 Cynthia Demicheli,6 Maria N Melo,7 Frédéric Frézard1 1Department of Physiology and Biophysics, 2Department of Morphology, Instituto de Ciências Biológicas (ICB, Universidade Federal de Minas Gerais (UFMG, 3Innovation and Technology Center SENAI FIEMG – Campus CETEC, 4Department of Physics, Instituto de Ciências Exatas (ICEX, 5Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais (UFMG, 6Department of Chemistry, Instituto de Ciências Exatas (ICEX, 7Department of Parasitology, Instituto de Ciências Biológicas (ICB, Universidade Federal de Minas Gerais (UFMG, Belo Horizonte, Brazil Abstract: There is a great need for orally active drugs for the treatment of the neglected tropical disease leishmaniasis. Amphiphilic Sb(V complexes, such as 1:3 Sb–N-octanoyl-N-methylglucamide complex (SbL8, are promising drug candidates. It has been previously reported that SbL8 forms kinetically stabilized nanoassemblies in water and that this simple dispersion exhibits antileishmanial activity when given by oral route to a murine model of visceral leishmaniasis. The main objective of the present work was to interfere in the structural organization of these nanoassemblies so as to investigate their influence on the oral bioavailability of Sb, and ultimately, optimize an oral formulation of SbL8 for the treatment of cutaneous leishmaniasis. The structural organization of SbL8 nanoassemblies was manipulated through addition of propylene glycol (PG to the aqueous dispersion of SbL8. The presence of 50% (v/v PG resulted in the loss of hydrophobic microenvironment, as evidenced by fluorescence probing. However, nanostructures were still present, as demonstrated by dynamic light scattering, small-angle X-ray scattering, and atomic force microscopy (AFM. A

Recent results on polarizations and the present status of the Fermilab polarized beams

International Nuclear Information System (INIS)

Yokosawa, Akihiko.

1986-01-01

Experimental results are reviewed on polarization phenomena in nucleon-nucleon scattering at intermediate energies. The present status of S = 0 dibaryon resonances is presented. The status of the Fermilab polarized beam program is presented, including the construction of polarized beam, two polarimeters being installed in the experimental hall, and the experimental program

Polarization transfer from polarized nuclear spin to μ- spin in muonic atom

International Nuclear Information System (INIS)

Kuno, Yoshitaka; Nagamine, Kanetada; Yamazaki, Toshimitsu.

1987-02-01

A theoretical study of polarization transfer from an initially-polarized nuclear spin to a μ - spin in a muonic atom is given. The switching of the hyperfine interaction at excited muonic states as well as at the ground 1s state is taken into account. The upper state of hyperfine doublet at the muonic 1s state is considered to proceed down to the lower state. It is found that as the hyperfine interaction becomes effective at higher excited muonic orbitals, a less extent of polarization is transferred from the nuclear spin to the μ - spin. The theoretical values obtained are compared with the recent experiment of μ - repolarization in a polarized 209 Bi target. (author)

Polarized proton beams since the ZGS

International Nuclear Information System (INIS)

Krisch, A.D.

1994-01-01

The author discusses research involving polarized proton beams since the ZGS's demise. He begins by reminding the attendee that in 1973 the ZGS accelerated the world's first high energy polarized proton beam; all in attendance at this meeting can be proud of this accomplishment. A few ZGS polarized proton beam experiments were done in the early 1970's; then from about 1976 until 1 October 1979, the majority of the ZGS running time was polarized running. A great deal of fundamental physics was done with the polarized beam when the ZGS ran as a dedicated polarized proton beam from about Fall 1977 until it shut down on 1 October 1979. The newly created polarization enthusiats then dispersed; some spread polarized seeds al over the world by polarizing beams elsewhere; some wound up running the High Energy and SSC programs at DOE

Polarization Optics in Telecommunications

CERN Document Server

Damask, Jay N

2005-01-01

The strong investments into optical telecommunications in the late 1990s resulted in a wealth of new research, techniques, component designs, and understanding of polarization effects in fiber. Polarization Optics in Telecommunications brings together recent advances in the field to create a standard, practical reference for component designers and optical fiber communication engineers. Beginning with a sound foundation in electromagnetism, the author offers a dissertation of the spin-vector formalism of polarization and the interaction of light with media. Applications discussed include optical isolators, optical circulators, fiber collimators, and a variety of applied waveplate and prism combinations. Also included in an extended discussion of polarization-mode dispersion (PMD) and polarization-dependent loss (PDL), their representation, behavior, statistical properties, and measurement. This book draws extensively from the technical and patent literature and is an up-to-date reference for researchers and c...

Avaliação do potencial biológico da Tabebuia aurea(Silva Manso como fonte de moléculas bioativas para atividade antimicrobiana, antiedematogênica e antirradicalar

Directory of Open Access Journals (Sweden)

R.F.E.P. SANTOS

2015-01-01

Full Text Available RESUMO As espécies da família Bignoniaceae e do gênero Tabebuia são amplamente utilizadas na medicina tradicional e possuem um forte potencial terapêutico. Diante disso, objetivou-se avaliar o potencial biológico da Tabebuia aurea, determinando a atividade antimicrobiana; por meio do método da microdiluição em caldo, para a determinação da Concentração Inibitória Mínima (CIM; antiedematogênica, pelo ensaio de edema de orelha induzido por capsaicina; e antirradicalar, frente ao radical DPPH. Os extratos etanólicos de T. aurea não evidenciaram citotoxicidade, exceto o extrato etanólico da flor nas concentrações > 0,5 mg mL-1. O extrato etanólico da flor foi ativo com ação bactericida frente a S. epidermidis (CIM de 0,06 mg mL-1 enquanto o extrato etanólico da folha foi moderadamente ativo frente a S. epidermidis (CIM: 0,25 mg mL-1 e S. aureus (CIM: 0,50 mg mL-1 sugerindo ação bacteriostática para ambas as linhagens. Os dois extratos apresentaram ação antiedematogênica, com inibição do edema de 40,50% pelo extrato etanólico da flor e de 41,73% pelo extrato da folha. T. aurea não apresentou atividade antirradicalar. Os resultados comprovam o perfil antibacteriano e antiedematogênico com ausência de citotoxidade pela T. aurea. Sugere-se a continuação dos testes com frações e substâncias isoladas das flores e folhas da referida espécie vegetal, bem como de experimentos in vivo, como forma de agregar evidências visando à busca de novos fitoterápicos.

Electroproduction of polarized Λ's

International Nuclear Information System (INIS)

Kunne, R.A.

1992-01-01

Lambdas are a powerful tool to explore spin effects of QCD. The λ polarization is self analyzing, as it is measurable from the angular distribution of the decay products. Two applications of polarized electroproduced λ's are suggested: the measurement of λ polarization at large transverse momentum as a possible test of QCD and the measurement of transversely polarized parton distributions

Polarized proton collider at RHIC

International Nuclear Information System (INIS)

Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N.

2003-01-01

In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to √s=500 GeV

Optical properties of polarization-dependent geometrical phase elements with partially polarized light

International Nuclear Information System (INIS)

Gorodetski, Y.; Biener, G.; Niv, A.; Kleiner, V.; Hasman, E.

2005-01-01

Full Text:The behavior of geometrical phase elements illuminated with partially polarized monochromatic beams is being theoretically as well as experimentally investigated. The element discussed in this paper is composed of wave plates with retardation and space-variant orientation angle. We found that a beam emerging from such an element comprises two polarization orders of right and left-handed circularly polarized states with conjugate geometrical phase modification. This phase equals twice the orientation angle of the space-variant wave plate comprising the element. Apart from the two polarization orders, the emerging beam coherence polarization matrix comprises a matrix termed as the vectorial interference matrix. This matrix contains the information concerning the correlation between the two orthogonal circularly polarized portions of the incident beam. In this paper we measure this correlation by a simple interference experiment. Furthermore, we found that the equivalent mutual intensity of the emerging beam is being modulated according to the geometrical phase induced by the element. Other interesting phenomena along propagation will be discussed theoretically and experimentally demonstrated. We demonstrate experimentally our analysis by using a spherical geometrical phase element, which is realized by use of space-variant sub wavelength grating and illuminated with a CO 2 laser radiation of 10.6μm wavelength

Aspectos biológico-pesqueros del pejerrey (Odontesthes regia regia) en el puerto de Ilo durante 1996-1998

OpenAIRE

Hugo Treviño; Walter Condori; Martín Zambrano

2014-01-01

Se analizaron los aspectos biológicos y pesqueros del pejerrey peruano (Odontesthes regia regia) población en Ilo, desde enero de 1996 a septiembre de 1998. Las capturas fueron tres veces más alta (72,76 t) que las de 1996 hasta 1997, mientras que con el calentamiento de "El Niño" en 1998 éstas se redujeron a 0,62 t. Durante el evento "El Niño 1997-1998" la población mostró también una serie de cambios en la distribución, la reproducción y la composición de la dieta. Estos cambios se asociaro...

POLARIZED BEAMS: 2 - Partial Siberian Snake rescues polarized protons at Brookhaven

International Nuclear Information System (INIS)

Huang, Haixin

1994-01-01

To boost the level of beam polarization (spin orientation), a partial 'Siberian Snake' was recently used to overcome imperfection depolarizing resonances in the Brookhaven Alternating Gradient Synchrotron (AGS). This 9-degree spin rotator recently permitted acceleration with no noticeable polarization loss. The intrinsic AGS depolarizing resonances (which degrade the polarization content) had been eliminated by betatron tune jumps, but the imperfection resonances were compensated by means of harmonic orbit corrections. However, at high energies these orbit corrections are difficult and tedious and a Siberian Snake became an attractive alternative

Nuclear physics with polarized particles

CERN Document Server

Paetz gen Schieck, Hans

2012-01-01

The measurement of spin-polarization observables in reactions of nuclei and particles is of great utility and advantage when the effects of single-spin sub-states are to be investigated. Indeed, the unpolarized differential cross-section encompasses the averaging over the spin states of the particles, and thus loses details of the interaction process. This introductory text combines, in a single volume, course-based lecture notes on spin physics and on polarized-ion sources with the aim of providing a concise yet self-contained starting point for newcomers to the field, as well as for lecturers in search of suitable material for their courses and seminars. A significant part of the book is devoted to introducing the formal theory-a description of polarization and of nuclear reactions with polarized particles. The remainder of the text describes the physical basis of methods and devices necessary to perform experiments with polarized particles and to measure polarization and polarization effects in nuclear rea...

The polarization of fast neutrons

International Nuclear Information System (INIS)

Talov, V.V.

2001-01-01

It is insufficient to know coordinates and momentum to describe a state of a neutron. It is necessary to define a spin orientation. As far as it is known from quantum mechanics, a half spin has a projection in the positive direction or in the negative direction. The probability of both projections in an unpolarized beam is equal. If a direction exists, in which the projection is more probably then beam is called polarized in this direction. It is essential to know polarization of neutrons for characteristics of a neutron source, which is emitting it. The question of polarization of fast neutrons came up in 50's. The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li (p,n) 7 Be, T(p,n) 3 He reactions. (authors)

Una reacción de bioluminiscencia que detecta Trifosfato de Adenosina (ATP) como determinante de suciedad biológica

OpenAIRE

Temprano, Guillermo; D'Aquino, Miguel

2004-01-01

Por medio de la bioluminiscencia se puede detectar la cantidad de ATP presente en una superficie. Esto se relaciona directamente con la suciedad biológica, entendiéndose por tal a la constituída por sustancias orgánicas de origen vegetal o animal, incluyéndose a los microorganismos. Es opinión generalizada que el ATP es rápidamente destruído luego de la muerte celular por acción de la ATPasa. En la presente comunicación se publican resultados que ponen en discusión esta afirmación...

Aspectos biológicos, morfológicos y genéticos de Hypothenemus obscurus e Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae)

OpenAIRE

CONSTANTINO, LUIS M.; NAVARRO, LUCIO; BERRIO, ALEJANDRO; ACEVEDO, FLOR E.; RUBIO, DAVID; BENAVIDES, PABLO

2011-01-01

Existen dos especies de Hypothenemus en Colombia de importancia económica: H. hampei y H. obscurus. La primera es la plaga más destructiva del café, mientras que la segunda ataca varias especies, incluyendo macadamia y café. El objetivo de esta investigación fue comparar estas dos especies, biológica, morfológica y genéticamente, con el fin de establecer diferencias que expliquen la adaptación de la broca al café. Los insectos fueron criados en dieta artificial de café y macadamia para estudi...

Stanford polarized atomic beam target

International Nuclear Information System (INIS)

Mavis, D.G.; Dunham, J.S.; Hugg, J.W.; Glavish, H.F.

1976-01-01

A polarized atomic beam source was used to produce an atomic hydrogen beam which was in turn used as a polarized proton target. A target density of 2 x 10'' atoms/cm 3 and a target polarization of 0.37 without the use of rf transitions were measured. These measurements indicate that a number of experiments are currently feasible with a variety of polarized target beams

Contaminación biológica intradomiciliaria y su relación con síntomas respiratorios indicativos de asma bronquial en preescolares de Bucaramanga, Colombia

Directory of Open Access Journals (Sweden)

Astrid Berena Herrera

2011-03-01

Conclusiones. La exposición a contaminantes biológicos intramurales (ácaros y hongos, los antecedentes personales de prematuridad, neumonía o rinitis y el antecedente familiar de asma, incrementan la probabilidad de presentación de síntomas indicativos de asma bronquial en la población estudiada.

Solar Spectral Lines with Special Polarization Properties for the Calibration of Instrument Polarization

Energy Technology Data Exchange (ETDEWEB)

Li, W.; Casini, R.; Alemán, T. del Pino; Judge, P. G. [High Altitude Observatory, National Center for Atmospheric Research 1, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

2017-10-20

We investigate atomic transitions that have previously been identified as having zero polarization from the Zeeman effect. Our goal is to identify spectral lines that can be used for the calibration of instrumental polarization of large astronomical and solar telescopes, such as the Daniel K. Inouye Solar Telescope, which is currently under construction on Haleakala. We use a numerical model that takes into account the generation of scattering polarization and its modification by the presence of a magnetic field of arbitrary strength. We adopt values for the Landé factors from spectroscopic measurements or semi-empirical results, thus relaxing the common assumption of LS-coupling previously used in the literature. The mechanisms dominating the polarization of particular transitions are identified, and we summarize groups of various spectral lines useful for the calibration of spectropolarimetric instruments, classified according to their polarization properties.

La Evolución biológica en la Biofilosofía de F. J. Ayala

Directory of Open Access Journals (Sweden)

Diego Cano Espinosa

2016-02-01

Full Text Available El discurso biológico de Ayala se centra en estas tres cuestiones: 1 El hecho de la evolución. 2 Historia de la evolución. 3 Mecanismos del desarrollo y cambio evolutivos. El hecho determinante y cierto, según Ayala, es la evidencia de relaciones entre todos los organismos debidas a una común descendencia con modificaciones como lo han demostrado con abundancia la Paleontología, Anatomía comparada, Biogeografía, Embriología, Genética Molecular, Bioinformática y otras disciplinas biológicas que nos llevan a la afirmación de que el hecho de la evolución de los seres vivos tiene el mismo grado de certeza que poseen los hechos históricos y científicos ampliamente confirmados. Para Ayala, explicaciones acerca del origen del mundo, del hombre y de otras criaturas se encuentran en todas las culturas. Tras la publicación del Origen de las Especies de C. Darwin en 1859, se produce gran polémica en los medios científicos, culturales y religiosos, pero pasado un período de maduración, el darwinismo logra ser aceptado especialmente bajo las formas de Neo-darwinismo y Teoría Sintética. Otro asunto muy distinto son las diversas teorías y micro-teorías que se proponen para explicar los mecanismos de la evolución de los organismos vivos que presentan todavía profundas lagunas, deficiencias y controversias que han provocado la aparición de teorías alternativas. No obstante, el darwinismo moderno constituye un peldaño importante en la reconstrucción del sinuoso y complejo proceso evolutivo de la vida a través de millones de años acudiendo a una razonable explicación causal sin que esto atente contra ningún supuesto religioso.

Polar transport in plants mediated by membrane transporters: focus on mechanisms of polar auxin transport.

Science.gov (United States)

Naramoto, Satoshi

2017-12-01

Directional cell-to-cell transport of functional molecules, called polar transport, enables plants to sense and respond to developmental and environmental signals. Transporters that localize to plasma membranes (PMs) in a polar manner are key components of these systems. PIN-FORMED (PIN) auxin efflux carriers, which are the most studied polar-localized PM proteins, are implicated in the polar transport of auxin that in turn regulates plant development and tropic growth. In this review, the regulatory mechanisms underlying polar localization of PINs, control of auxin efflux activity, and PIN abundance at PMs are considered. Up to date information on polar-localized nutrient transporters that regulate directional nutrient movement from soil into the root vasculature is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Parallel Polarization State Generation.

Science.gov (United States)

She, Alan; Capasso, Federico

2016-05-17

The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

Miopia aguda induzida por topiramato: relato de dois casos

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Kathy Dadam Sgrott

2011-06-01

Full Text Available RESUMO A miopia aguda pode ser desencadeada pelo uso de medicações sistêmicas, dentre elas, o anticonvulsivante topiramato. Este trabalho descreve dois casos de pacientes jovens com quadro agudo bilateral de miopia induzida por terapia com topiramato para controle de síndrome depressiva, fazendo relação com casos semelhantes descritos na literatura e revisão bibliográfica pertinente.

Polarized deuteron elastic scattering from a polarized proton target

International Nuclear Information System (INIS)

Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R.; Zankel, H.

1983-01-01

Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76 0 ,85 0 ,98 0 ,115 0 ,132 0 ). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results. (orig.)

Polarized vacuum ultraviolet and X-radiation

International Nuclear Information System (INIS)

Samson, J.A.R.

1978-01-01

The most intense source of polarized vacuum UV and X-radiation is synchrotron radiation, which exhibits a degree of partially polarized light between about 80-100%. However, the radiation transmitted by vacuum UV monochromators can also be highly polarized. The Seya-Namioka type of monochromator can produce partially polarized radiation between 50-80%. For certain experiments it is necessary to know the degree of polarisation of the radiation being used. Also, when synchrotron radiation and a monochromator are combined the polarization characteristic of both should be known in order to make full use of these polarization properties. The polarizing effect on monochromators (i.e. diffraction gratings) have been measured at the Seya angle and at grazing angles for various spectral orders. The author presents the first experimental evidence that the reciprocity law holds for polarization by reflection where the angle of incidence and diffraction are unequal. These results are reviewed along with the techniques for measuring the degree of polarization. (Auth.)

Broadband dielectric spectroscopy of phonons and polar nanoclusters in PbMg.sub.1/3./sub.Nb.sub.2/3./sub.O.sub.3./sub.-35%PbTiO.sub.3./sub. ceramics: Grain size effects

Czech Academy of Sciences Publication Activity Database

Bovtun, Viktor; Kamba, Stanislav; Veljko, Sergiy; Nuzhnyy, Dmitry; Kroupa, Jan; Savinov, Maxim; Vaněk, Přemysl; Petzelt, Jan; Holc, J.; Kosec, M.; Amorin, H.; Alguero, M.

2009-01-01

Roč. 79, č. 10 (2009), 104111/1-104111/12 ISSN 1098-0121 R&D Projects: GA MŠk OC 101; GA ČR(CZ) GA202/09/0682; GA ČR(CZ) GA202/06/0403; GA MŠk OC09023 Institutional research plan: CEZ:AV0Z10100520 Keywords : polar clusters * relaxor ferroelectrics * soft modes * phonons Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.475, year: 2009 http://link.aps.org/doi/10.1103/PhysRevB.79.104111

Efecto de la fertilización química y biológica en el rendimiento morfoagronómico de Morus alba

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Yolai Noda

Full Text Available Se evaluó el efecto de la fertilización química nitrogenada, la micorriza vesículo arbuscular (MVA Glomus fasciculatum y la fitohormona brasinoesteroide Biocep-6, en las características morfoagronómicas de Morus alba var. Acorazonada. Para ello se usaron tres dosis de fertilización (0, 150 y 300 kg de N/ha/año, dos con y sin Ecomic® y dos con y sin Biocep-6, lo que originó un total de 12 tratamientos. Se seleccionaron al azar cinco plantas y en ellas se estudiaron las variables altura, número de ramas primarias y rendimiento de la materia seca de: la biomasa total (RMSBT, la comestible (RMSBC, las hojas (RMSH y los tallos tiernos (RMSTT. Se observó una relación directa entre la altura y el rendimiento, así como el efecto del Biocep-6 en el número de ramas primarias. El RMSBT fue de 18,25; 17,24; 17,56; 18,43; 17,04; 17,22 y 18,31 t de MS/ha/año en T4, T5, T6, T8, T9, T11 y T12, respectivamente. El RMSBC, el RMSH y el RMSTT se comportaron de manera diferente, según cada tratamiento. Se concluye que la sinergia entre los fertilizantes biológicos y los químicos fue notable para todas las variables morfoagronómicas. Los tratamientos Ecomic® + Biocep-6 y 150 kg de N/ha/año + Ecomic® + Biocep-6 fueron significativamente superiores para todas las variables. Los rendimientos de materia seca total y comestible obtenidos con la fertilización biológica y la mineral estuvieron dentro del rango reportado por otros autores. Se recomienda el uso combinado de Ecomic® + Biocep-6 para obtener buenos rendimientos agrícolas en M. alba, así como continuar los estudios de la composición bromatológica para determinar el efecto de las combinaciones de fertilizantes químicos y biológicos.

Hérnias intradural de discos lombares: relato de dois casos

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Joel M. Guelmann

1972-09-01

Full Text Available São relatados dois casos de hérnia de disco lombar intradural. Os autores salientam a raridade desta ocorrência e fazem comentários sobre os fatores que podem determina-la. Ambos os pacientes foram operados, com extirpação total da hérnia. Houve completa recuperação dos pacientes.

Teoría de agencia: una revisión del origen biológico del delito

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Iván Araya

2016-01-01

Full Text Available Este trabajo aborda la causa del conflicto entre principal y agente, buscando respuestas en las disciplinasde la biología, particularmente en las ciencias de la antropología criminal. Se ha realizado un ensambleentre los hallazgos de la teoría de agencia y la teoría de los delitos de cuello blanco, reinterpretando lasactuaciones del agente desde su configuración entre instinto, herencia y personalidad. Los resultadosen las ciencias biológicas podrían aportar nuevas interpretaciones y explicaciones en las ciencias de laadministración, avanzando hacia mejores conceptualizaciones del conflicto, mediante teorías con mayorcontenido empírico. En general, pese al conflicto permanente entre las partes, su dinámica potencia losresultados perseguidos por el principal.

Spin-polarized photoemission

International Nuclear Information System (INIS)

Johnson, Peter D.

1997-01-01

Spin-polarized photoemission has developed into a versatile tool for the study of surface and thin film magnetism. In this review, we examine the methodology of the technique and its application to a number of different problems, including both valence band and core level studies. After a detailed review of spin-polarization measurement techniques and the related experimental requirements we consider in detail studies of the bulk properties both above and below the Curie temperature. This section also includes a discussion of observations relating to unique metastable phases obtained via epitaxial growth. The application of the technique to the study of surfaces, both clean and adsorbate covered, is reviewed. The report then examines, in detail, studies of the spin-polarized electronic structure of thin films and the related interfacial magnetism. Finally, observations of spin-polarized quantum well states in non-magnetic thin films are discussed with particular reference to their mediation of the oscillatory exchange coupling in related magnetic multilayers. (author)

A review of polarized ion sources

International Nuclear Information System (INIS)

Schmor, P.W.

1995-06-01

The two main types of polarized ion sources in use on accelerators today are the Atomic Beam Polarized Ion Source (ABIS) source and the Optically Pumped Polarized Ion Source (OPPIS). Both types can provide beams of nuclearly polarized light ions which are either positively or negatively charged. Heavy ion polarized ion sources for accelerators are being developed. (author). 35 refs., 1 tab

Polarization phenomena in heavy-ion reactions

International Nuclear Information System (INIS)

Sugimoto, K.; Ishihara, M.; Takahashi, N.

1984-01-01

This chapter presents a few key experiments which provide direct evidence of the polarization phenomena in heavy-ion reactions. The theory of polarization observables and measurements is given with the necessary formulae. The polarization phenomena is described and studies of product nuclear polarization in heavy-ion reactions are discussed. Studies of heavy-ion reactions induced by polarized beams are examined

Dynamic nuclear polarization tests in some polymers for polarized targets

International Nuclear Information System (INIS)

Brandt, B. van den; Hautle, P.; Konter, J.A.; Mango, S.; Bunyatova, E.I.

1998-01-01

The results of dynamic polarization tests in polyethylene (PE) and ethylene propylene copolymer (EPC), doped with the stable free radical 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), are presented. Sizable proton polarizations have been achieved in a magnetic field of 2.5 T at a temperature below 0.3 K and 5T at 1 K

Broad-aperture polarized proton target with arbitrary orientation of polarization vector

International Nuclear Information System (INIS)

Belyaev, A.A.; Get'man, V.A.; Derkach, A.Ya.; Karnaukhov, I.M.; Lukhanin, A.A.; Razumnyj, A.A.; Sorokin, P.V.; Sporov, E.A.; Telegin, Yu.N.; Trotsenko, V.I.

1985-01-01

Polarized proton target with the Helmholtz broad-aperture superconducting magnetic system is described. Axial aperture α=95 deg, inter-coil access angle β=23 deg. The structure of the target allows various versions of the installation what make sure an arbitrary orientation of polarization vector. The 0.1 W cold output 3 He evaporation cryostat was used to obtain the work temperature 0.5 K allowing quick transformation to a 3 He- 4 He dilution refrigerator. Results of the study are given on the dynamical proton polarization in 1,2-propylenglycol with various stable Cr 5 complexes

Gestión del riesgo biológico y su integración con la Seguridad y Salud del Trabajo en el Centro de Inmunología y Biopreparados de Cuba Biohazard management and its integration into Labor Health at the Immunology and Bioproducts Centre in Cuba

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Dailín Cobos Valdes

2011-06-01

Full Text Available La evaluación de riesgos es útil para planificar y mejorar la Seguridad Biológica, el control de la calidad y la Seguridad y Salud en el Trabajo, considerando el marco legal vigente en Cuba y la inspección constituye una parte importante de estos procesos. Con el objetivo de identificar y evaluar el riesgo biológico en el Centro de Inmunología y Biopreparados se realizó esta investigación. La misma incluyó la identificación del riesgo biológico en tres áreas, la evolución de inspecciones de Seguridad Biológica y las medidas correctivas recomendadas. Los resultados permitieron diseñar e implementar el Reglamento de Seguridad en el se integraron las funciones de Seguridad Biológica y Seguridad y Salud en el Trabajo.Risk assessments are useful to plan and improve biological safety, quality control and in general health and safety at work, taking into account the legal framework in Cuba. Supervision is an important part of these processes. Research was done in order to identify and to evaluate the biohazard in the Immunology and Bioproducts Centre (CIBHO. It included the identification and risk assessment in three areas, the biological safety supervisions and its evolution and the corrective measures recommended. The results allowed to design and to implement a Safety Regulation which includes measures for biological safety and health and safety at work.

“Bem biológico mesmo”: tensões entre ensino de biologia, currículo e sexualidade

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Neilton dos Reis

2018-01-01

Full Text Available Neste artigo, apresentamos uma argumentação teórica acerca da construção curricular e história das disciplinas escolares de Ciências e de Biologia e suas relações com os saberes do campo de gênero e sexualidade. Partimos da apresentação e problematização de uma das entrevistas que compuseram a pesquisa “Diversidade de Gêneros e Ensino de Biologia: casos de prazeres e corporeidades não-binárias” para, então, pensar como essas disciplinas se constituem, legitimando, ou não, determinados conhecimentos e conteúdos curriculares. Com isso, propomos uma ação questionadora dos posicionamentos que os currículos vêm promulgando, de forma a repensar os contornos nos quais a sexualidade tem sido delimitada na área das Ciências Biológicas. Palavras-chave: Currículo. Ensino de Biologia. Sexualidade.   “Really biological”: tensions between biology education, curriculum and sexuality ABSTRACT In this article, it is introduced a theoretical argumentation about curricular construction and scholar disciplines story of Science and Biology, and its relations to the knowledge about gender and sexuality. We started from presentation and questioning of one of the interviews that were included in the survey “Gender Diversity and Biology Education: Case of pleasures and corporealities non-binary” to then, think how these disciplines are legitimizing, or not, certain knowledge and content curriculum. Therefore, we propose an action questioning of the positions that curriculum have been promulgating in order to rethink the contours in which sexuality has been defined in the area of Biological Sciences. Keywords: Curriculum. Biology education. Sexuality.   “Bien biológico mismo”: tensiones entre la enseñanza de la biología, currículo y sexualidad RESUMEN En este artículo, presentamos una argumentación teórica acerca de la construcción curricular y de la historia de las disciplinas escolares de Ciencias y de Biología y

Do embryonic polar bodies commit suicide?

Science.gov (United States)

Fabian, Dušan; Čikoš, Štefan; Rehák, Pavol; Koppel, Juraj

2014-02-01

The extrusion and elimination of unnecessary gametic/embryonic material is one of the key events that determines the success of further development in all living organisms. Oocytes produce the first polar body to fulfill the maturation process just before ovulation, and release the second polar body immediately after fertilization. The aim of this study was to compile a physiological overview of elimination of polar bodies during early preimplantation development in mice. Our results show that three-quarters of the first polar bodies were lost even at the zygotic stage; the 4-cell stage embryos contained only one (second) polar body, and the elimination of second polar bodies proceeded continuously during later development. Both first and second polar bodies showed several typical features of apoptosis: phosphatidylserine redistribution (observed for the first time in the first polar body), specific DNA degradation, condensed nuclear morphology, and inability to exclude cationic dye from the nucleus during the terminal stage of the apoptotic process. Caspase-3 activity was recorded only in the second polar body. From the morphological point of view, mouse polar bodies acted very similarly to damaged embryonic cells which have lost contact with their neighboring blastomeres. In conclusion, polar bodies possess all the molecular equipment necessary for triggering and executing an active suicide process. Furthermore, similarly as in dying embryonic cells, stressing external conditions (culture in vitro) might accelerate and increase the incidence of apoptotic elimination of the polar bodies in embryos.

Lodo de esgoto em atributos biológicos do solo e na nodulação e produção de soja Sewage sludge effects on soil biological parameters and on soybean nodulation and yield

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Carla Albuquerque de Souza

2009-10-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos da aplicação do lodo produzido pela Companhia de Saneamento Ambiental do Distrito Federal (Caesb na nodulação e rendimento de grãos da soja e em atributos biológicos de um Latossolo Vermelho de Cerrado. O experimento foi conduzido por dois anos consecutivos em um delineamento experimental de blocos ao acaso com três repetições e nove tratamentos - um controle, quatro doses de lodo de esgoto e quatro doses de fertilizante mineral - aplicados apenas no primeiro ano de cultivo. Foram avaliados: a nodulação e a produtividade da soja, o carbono da biomassa microbiana, o carbono prontamente mineralizável e a atividade das enzimas beta-glicosidase, fosfatase ácida e arilsulfatase no solo. Nos dois anos agrícolas, o rendimento de grãos da soja foi inferior ao do tratamento com o fertilizante mineral somente na dose de 1,5 Mg ha-1 de lodo de esgoto. A aplicação do lodo de esgoto no primeiro ano de cultivo não afetou a nodulação da soja, e a aplicação de até 6 Mg ha-1 não apresentou efeito sobre o carbono da biomassa microbiana, o carbono prontamente mineralizável e a atividade das enzimas beta-glicosidase, arilsulfatase e fosfatase ácida do solo no período de dois anos.The objective of this study was to evaluate the effects of applying sewage sludge produced by the Companhia de Saneamento Ambiental do Distrito Federal (Caesb on the nodulation and yield of soybean and on the biological parameters of a Cerrado Oxisol. The experiment was done for two consecutive years in a completely randomized block design with three replicates and nine treatments - one control, four dosages of sewage sludge and four dosages of mineral fertilizer - applied only in the first year of the experiment. Soybean nodulation, grain yield, soil microbial biomass carbon, readily mineralizable carbon and activity of the beta-glucosidase, acid phosphatase and arylsulphatase enzymes were evaluated. In both years

Spin exchange in polarized deuterium

International Nuclear Information System (INIS)

Przewoski, B. von; Meyer, H.O.; Balewski, J.; Doskow, J.; Ibald, R.; Pollock, R.E.; Rinckel, T.; Wellinghausen, A.; Whitaker, T.J.; Daehnick, W.W.; Haeberli, W.; Schwartz, B.; Wise, T.; Lorentz, B.; Rathmann, F.; Pancella, P.V.; Saha, Swapan K.; Thoerngren-Engblom, P.

2003-01-01

We have measured the vector and tensor polarization of an atomic deuterium target as a function of the target density. The polarized deuterium was produced in an atomic beam source and injected into a storage cell. For this experiment, the atomic beam source was operated without rf transitions, in order to avoid complications from the unknown efficiency of these transitions. In this mode, the atomic beam is vector and tensor polarized and both polarizations can be measured simultaneously. We used a 1.2-cm-diam and 27-cm-long storage cell, which yielded an average target density between 3 and 9x10 11 at/cm 3 . We find that the tensor polarization decreases with increasing target density while the vector polarization remains constant. The data are in quantitative agreement with the calculated effect of spin exchange between deuterium atoms at low field

Study by polarized muon

International Nuclear Information System (INIS)

Yamazaki, Toshimitsu

1977-01-01

Experiments by using polarized muon beam are reported. The experiments were performed at Berkeley, U.S.A., and at Vancouver, Canada. The muon spin rotation is a useful method for the study of the spin polarization of conductive electrons in paramagnetic Pd metal. The muon Larmor frequency and the relaxation time can be obtained by measuring the time distribution of decay electrons of muon-electron process. The anomalous depolarization of negative muon spin rotation in the transitional metal was seen. The circular polarization of the negative muon X-ray was measured to make clear this phenomena. The experimental results show that the anomalous depolarization is caused at the 1-S-1/2 state. For the purpose to obtain the strong polarization of negative muon, a method of artificial polarization is proposed, and the test experiments are in progress. The study of the hyperfine structure of mu-mesic atoms is proposed. The muon capture rate was studied systematically. (Kato, T.)

DOI - Digital Object Identifier : A revolution in the management and trading of copyrighted information over the Internet in the third millenium

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Martin Žnideršič

1997-01-01

Full Text Available Rapid development of information technology in recent years has brought over also the problem of the protection of author's rights related to copyrighted works on electronic media. Information and law specialists were intensively working on this problem for several years and the result has been a new system of labelling copyrighted works on the Internet, called DOI (Digitial Object Identifier. The system was developed in the United States. At the time of the presenta tion of DOI at the Bookfair in Frankfurt, 250.000 author works were labelled with DOI. The system is universal and enables the inclusion of the present standard identifiers (ISBN, ISSN, SICI. The fact that DOI identifier stays "glued on" forever, makes the identification of the carrier of copyright possible at any moment. The DOI system presents the infrastructure system for trading in and use of copyrighted works over the Internet in the third millenium.

ACCELERATION OF POLARIZED PROTONS AT RHIC

International Nuclear Information System (INIS)

HUANG, H.

2002-01-01

Relativistic Heavy Ion Collider (RHIC) ended its second year of operation in January 2002 with five weeks of polarized proton collisions. Polarized protons were successfully injected in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. This is the first time that polarized protons have been accelerated to 100 GeV. The machine performance and accomplishments during the polarized proton run will be reviewed. The plans for the next polarized proton run will be outlined

Patrones de nerviación foliar en Myrtaceae de la Estación Biológica La Selva, provincia de Heredia, Costa Rica

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J. Gabriela Jolochin

2015-07-01

Full Text Available Se realizaron descripciones de la arquitectura foliar, con énfasis en patrones de nerviación, de cuatro géneros y 14 especies de Myrtaceae incluyendo dos especies citadas como exóticas, para la Estación Biológica La Selva, OET, Heredia, Costa Rica. El material fresco descrito fue coleccionado en la estación biológica y fueron visitados los herbarios INB y CR, además de consultar el herbario de la propia estación e imágenes del MO. El 85% de las especies presentan un patrón de nerviación secundaria camptódromo- broquidódromo y ca. 50% poseen nervaduras secundarias rectas, que sólo se curvan cercanas al margen simulando una nervadura intramarginal. Las nervaduras terciarias son detectables a simple vista sólo en siete de las especies, de las cuales cuatro poseen un patrón reticulado y la nerviación última marginal en arcos o no visible. La combinación de los datos de arquitectura foliar con patrones de nerviación permitió discriminar las especies y obtener una clave de determinación de fácil uso en el campo.

Variables físicas, químicas y biológicas del suelo sobre las poblaciones de colémbolos en Costa Rica

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Cesar Guillen

2006-01-01

Full Text Available Se ha discutido que las variables físicas, químicas y biológicas del suelo influyen sobre las poblaciones de colémbolos; sin embargo, la información acerca de la interacción de estas variables, en conjunto, con relación a la diversidad y abundancia de colémbolos, es escasa. En el presente estudio se determinó la relación entre estas variables y la diversidad y abundancia de colémbolos en los suelos de un bosque primario, un bosque secundario y un cafetal en el Parque Nacional Tapantí. El bosque primario presentó los contenidos más altos de materia orgánica y biomasa microbiana, contrario a lo sucedido con la resistencia a la penetración y el pH. Los resultados mostraron una clara asociación entre estas variables y algunas especies de colémbolos, lo cual indica que los cambios en la estructura de las comunidades de colémbolos, por efecto de los cambios en las variables físicas, químicas y biológicas del suelo, pueden ser utilizados como un bioindicador de calidad del suelo y de manejo de los ecosistemas.

Polarized deuteron elastic scattering from a polarized proton target

Energy Technology Data Exchange (ETDEWEB)

Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Physikalisches Inst.); Zankel, H. (Graz Univ. (Austria). Inst. fuer Theoretische Physik)

1983-01-13

Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76/sup 0/,85/sup 0/,98/sup 0/,115/sup 0/,132/sup 0/). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results.

Avaliação de atividades biológicas dos extratos de Rosmarinus officinalis L. (alecrim) e Thymus vulgaris L. (tomilho)

OpenAIRE

Oliveira, Jonatas Rafael de [UNESP

2016-01-01

No presente estudo foram avaliadas algumas atividades biológicas dos extratos de R. officinalis L. (alecrim) e T. vulgaris L. (tomilho), verificando: I. Atividade antimicrobiana sobre biofilmes monomicrobianos de Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans e Pseudomonas aeruginosa e associações de C. albicans com cada uma destas bactérias, após determinação da concentração inibitória mínima (CIM) e concentração microbicida mínima (CMM) sobre culturas p...

The Polarization of Achernar

Science.gov (United States)

McDavid, D.

2005-11-01

Recent near-infrared measurements of the angular diameter of Achernar (the bright Be star alpha Eridani) with the ESO VLT interferometer have been interpreted as the detection of an extremely oblate photosphere, with a ratio of equatorial to polar radius of at least 1.56 ± 0.05 and a minor axis orientation of 39° ± 1° (from North to East). The optical linear polarization of this star during an emission phase in 1995 September was 0.12 ± 0.02% at position angle 37° ± 8° (in equatorial coordinates), which is the direction of the projection of the rotation axis on the plane of the sky according to the theory of polarization by electron scattering in an equatorially flattened circumstellar disk. These two independent determinations of the orientation of the rotation axis are therefore in agreement. The observational history of correlations between Hα emission and polarization as found in the literature is that of a typical Be star, with the exception of an interesting question raised by the contrast between Schröder's measurement of a small polarization perpendicular to the projected rotation axis in 1969--70 and Tinbergen's measurement of zero polarization in 1974.5, both at times when emission was reportedly absent.

Uso de “wetland” construído para tratamento de resíduos - DOI: 10.4025/actascibiolsci.v30i3.5002 Constructed wetland in wastewater treatment - DOI: 10.4025/actascibiolsci.v30i3.5002

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Lúcia Helena Sipaúba-Tavares

2008-10-01

Full Text Available Variáveis físico-químicas da água e do solo foram avaliadas a fim de verificar a eficiência de um “wetland” construído no tratamento de resíduos. Foram escolhidas oito espécies de macrófitas baseadas na capacidade de retenção e disponibilidade no local de estudo. Dentre elas estão: Eichhornia crassipes, Alternanthera philoxerodos, Heteranthera reniformis, Hydrocotyle umbeliferae, Ludwigia elegan, Ludwigia sericea, Myriophyllum aquaticum e Thypha domingensis. Foram amostrados dois pontos um na entrada e outro na saída de água do “wetland”. Diferenças significativas (p -1 e de condutividade, acima de 80 µS cm-1. As concentrações de clorofila-a decresceram ao passar pelo “wetland”, sendo mais elevadas no período de chuva (período de engorda de peixe. Amônia, fósforo total, DBO5, fósforo e matéria orgânica do sedimento decresceram ao passar pelo “wetland” construído para indicar a eficiência desse sistema. Assim, essa tecnologia biológica (macrófitas aquáticas apresenta-se como uma opção adequada para melhoria de efluentes de aquicultura e de suinocultura.Physical and chemical variables of soil and water were measured to determine the effectiveness of a constructed wetland for wastewater treatment. Eight different macrophyte species, namely Eichhornia crassipes, Alternanthera philoxerodos, Heteranthera reniformis, Hydrocotyle umbeliferae, Ludwigia elegan, Ludwigia sericea, Myriophyllum aquaticum and Thypha domingensis, were transplanted. Inlet water and outlet water were the two sampling sites evaluated. There were significant differences (p -1, and conductivity was high, above 80 µS cm-1. Chlorophyll-a levels generally tended to decrease at the wetland outlet and were higher during the rainy period (fish growth period. Results show that ammonia, total phosphorus, BOD5, phosphorus and organic matter in the sediment removals in the constructed wetland were higher, indicating that macrophytes played an

Polarization-Insensitive Surface Plasmon Polarization Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide

Science.gov (United States)

Jin, Lin; Wen, Long; Liang, Li; Chen, Qin; Sun, Yunfei

2018-02-01

CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific polarization state. In this case, it will lead to a high polarization dependent loss, when the polarization-sensitive modulator integrates to a fiber with random polarization state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and horizontal polarized guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the polarization state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both polarizations in our proposed modulator. Further, the polarization-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and horizontal polarized modes. For the optimized geometry configuration, the difference between the ER values of two polarization modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both polarizations at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random polarization state.

Optically pumped electron spin polarized targets for use in the production of polarized ion beams

International Nuclear Information System (INIS)

Anderson, L.W.

1979-01-01

The production of relatively dense electron spin polarized alkali metal vapor targets by optical pumping with intense cw dye lasers is discussed. The target density and electron spin polarization depend on the dye laser intensity and bandwidth, the magnetic field at the target, and the electron spin depolarization time. For example in a magnetic field of 1.5 x 10 3 G, and using 1 W dye laser with a bandwidth of 10 10 Hz one can construct an electron spin polarized Na vapor target with a target thickness of 1.6 x 10 13 atoms/cm 2 and an average electron spin polarization of about 90% even though the Na atoms are completely depolarized at every wall collision. Possible uses of the electron spin polarized targets for the production of intense beams of polarized H - or 3 He - ions are discussed. (orig.)

Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

International Nuclear Information System (INIS)

Green, M.C.

1984-01-01

A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target

Design of a tensor polarized deuterium target polarized by spin-exchange with optically pumped NA

International Nuclear Information System (INIS)

Green, M.C.

1984-05-01

A proposed design for a tensor polarized deuterium target (approx. 10 15 atoms/cm 2 ) for nuclear physics studies in an electron storage ring accelerator is presented. The deuterium atoms undergo electron spin exchange with a highly polarized sodium vapor; this polarization is transferred to the deuterium nuclei via the hyperfine interaction. The deuterium nuclei obtain their tensor polarization through repeated electron spin exchange/hyperfine interactions. The sodium vapor polarization is maintained by standard optical pumping techniques. Model calculations are presented in detail leading to a discussion of the expected performance and the technical obstacles to be surmounted in the development of such a target. 15 references, 10 figures

Sources of linear polarized x-rays

International Nuclear Information System (INIS)

Aiginger, H.; Wobrauschek, P.

1989-01-01

Linear polarized X-rays are used in X-ray fluorescence analysis to decrease the background caused by scattered photons. Various experiments, calculations and constructions have demonstrated the possibility to produce polarized radiation in an analytical laboratory with an X-ray tube and polarizer-analyzer facilities as auxiliary equipment. The results obtained with Bragg-polarizers of flat and curved focussing geometry and of Barkla-polarizers are presented. The advantages and disadvantages of the method are discussed and compared with the respective quality of synchrotron radiation. Polarization by scattering reduces the intensity of the primary radiation. Recently much effort is devoted to the construction of integrated high power X-ray tube polarizer-analyzer arrangements. The detailed design, geometry and performance of such a facility is described. (author)

Physics with polarized electron beams

International Nuclear Information System (INIS)

Swartz, M.L.

1988-01-01

As a distinct field, elementary particle physics is now approximately forty years old. In all that time, only a few of the thousands of experiments that have been performed have made use of spin polarized particle beams (with apologies to those who have studied neutrino interactions, polarized beam are defined to refer to the case in which the experimenter has control over the polarization direction). If the discussion is restricted to spin polarized electron beams, the number of experiments becomes countable with the fingers of one hand (with several to spare). There are two reasons for this lack of interest. The first is that spin polarized beams are difficult to produce, accelerate, and transport. The second reason is that any physical process that can occur during the collision of a polarized particle with another (polarized or not) can also occur during the collision of unpolarized particles. One might ask then, why has any effort been expended on the subject. The answer, at least in the case of polarized electron beams, is that electron accelerators and storage rings have in recent years achieved sufficient energy to begin to probe the weak interaction directly. The weak interaction distinguishes between left- and right-handed fermionic currents. Left-handed particles interact in a fundamentally different way than their right-handed counterparts. If the experimenter wishes to explore or exploit this difference, he (or she) must either prepare the spin state of the incident particles or analyze the spin state of outgoing particles. For reasons of genearlity and improved statistical precision, the former is usually preferable to the latter. The first of these lectures will review some of the techniques necessary for the production, transport, and monitoring of polarized electron (or positron) beams. The second lecture will survey some of the physics possibilities of polarized electron-positron collisions

New design of a quasi-monolithic detector module with DOI capability for small animal pet

International Nuclear Information System (INIS)

Chung, Yong Hyun; Lee, Seung-Jae; Baek, Cheol-Ha; Choi, Yong

2008-01-01

We report a new design of a detector module with depth of interaction (DOI) based on a quasi-monolithic LSO crystal, a multi-channel sensor, and maximum-likelihood position-estimation (MLPE) algorithm. Light transport and detection were modeled in a quasi-monolithic crystal using DETECT2000 code, with lookup tables (LUTs) built by simulation. Events were well separated by applying the MLPE method within 2.0 mm spatial resolution in both trans-axial and DOI directions. These results demonstrate that the proposed detector provides dependable positioning capability for small animal positron emission tomography (PET)

Multiphoton polarization Bremsstrahlung effect

International Nuclear Information System (INIS)

Golovinskij, P.A.

2001-01-01

A general approach to induced polarization effects was formulated on the basis of theory of many particles in a strong periodic field. Correlation with the perturbation theory is shown and the types of effective polarization potentials both for isolated atoms and ions, and for ions in plasma, are provided. State of art in the theory of forced polarization Bremsstrahlung effect is analyzed and some outlooks for further experimental and theoretical studies are outlined [ru

La infección por el virus del papiloma humano, un posible marcador biológico de comportamiento sexual en estudiantes universitarios

Directory of Open Access Journals (Sweden)

Sánchez-Alemán Miguel A

2002-01-01

Full Text Available Objetivo. Estimar la prevalencia de infección por el virus del papiloma humano (VPH en estudiantes universitarios y utilizar dicha frecuencia como un marcador biológico para evaluar el comportamiento sexual. Material y métodos. Se realizó un estudio transversal, en estudiantes de la Universidad Autónoma del estado de Morelos, México, durante el periodo 2000-2001. Se aplicó un cuestionario y se colectaron muestras genitales para detectar ADN de los VPH oncogénicos. Los datos se analizaron utilizando pruebas de Ji cuadrada y razones de momios. Resultados. La prevalencia global del VPH en 194 estudiantes fue de 14.4%. Las mujeres con dos o más parejas sexuales durante el último año presentaron mayor riesgo de infección por el VPH (RM 6.0 IC 1.7-21.1, al igual que las que utilizaron anticonceptivos hormonales y espermicidas en su última relación sexual (RM 3.0 IC 1.0-8.7. Los hombres que consumieron cocaína tuvieron más riesgo de infección por el VPH (RM 7.6 IC 1.3-45.1. Conclusiones. La prevalencia del VPH es relativamente alta. La utilización del VPH como un marcador biológico de comportamientos sexuales en mujeres es pertinente; en hombres, es necesario ampliar la muestra.

EDITORIAL: Non-polar and semipolar nitride semiconductors Non-polar and semipolar nitride semiconductors

Science.gov (United States)

Han, Jung; Kneissl, Michael

2012-02-01

Throughout the history of group-III-nitride materials and devices, scientific breakthroughs and technological advances have gone hand-in-hand. In the late 1980s and early 1990s, the discovery of the nucleation of smooth (0001) GaN films on c-plane sapphire and the activation of p-dopants in GaN led very quickly to the realization of high-brightness blue and green LEDs, followed by the first demonstration of GaN-based violet laser diodes in the mid 1990s. Today, blue InGaN LEDs boast record external quantum efficiencies exceeding 80% and the emission wavelength of the InGaN-based laser diode has been pushed into the green spectral range. Although these tremenduous advances have already spurred multi-billion dollar industries, there are still a number of scientific questions and technological issues that are unanswered. One key challenge is related to the polar nature of the III-nitride wurtzite crystal. Until a decade ago all research activities had almost exclusively concentrated on (0001)-oriented polar GaN layers and heterostructures. Although the device characteristics seem excellent, the strong polarization fields at GaN heterointerfaces can lead to a significant deterioration of the device performance. Triggered by the first demonstration non-polar GaN quantum wells grown on LiAlO2 by Waltereit and colleagues in 2000, impressive advances in the area of non-polar and semipolar nitride semiconductors and devices have been achieved. Today, a large variety of heterostructures free of polarization fields and exhibiting exceptional electronic and optical properties have been demonstrated, and the fundamental understanding of polar, semipolar and non-polar nitrides has made significant leaps forward. The contributions in this Semiconductor Science and Technology special issue on non-polar and semipolar nitride semiconductors provide an impressive and up-to-date cross-section of all areas of research and device physics in this field. The articles cover a wide range of

Adoção tardia: altruísmo, maturidade e estabilidade emocional

Directory of Open Access Journals (Sweden)

Ebrahim Surama Gusmão

2001-01-01

Full Text Available A pesquisa teve por objetivo executar um estudo acerca das adoções tardias, comparando pais que realizaram adoções de crianças maiores de dois anos com pais que efetuaram adoções de bebês. Os principais elementos abordados foram: estado civil; idade; escolaridade; renda; presença de filhos biológicos; e motivações para a adoção. Investigaram-se também o altruísmo, a maturidade e a estabilidade emocional dos adotantes. A amostra consistiu de 27 adotantes tardios e 55 adotantes convencionais, participantes ou não de Grupos de Apoio à Adoção. O instrumento utilizado constou de um questionário sobre adoção; de questões sobre maturidade e estabilidade emocional; e de uma escala de altruísmo. Os resultados indicaram distinções referentes aos aspectos destacados. Os adotantes tardios apresentaram um nível sócio-econômico superior, um estado civil mais diferenciado, uma maior presença de filhos biológicos, e uma maturidade e estabilidade mais elevada. Quanto às motivações e ao altruísmo, apareceram diferenças significativas entre os dois grupos.

Our Polar Past

Science.gov (United States)

Clary, Renee; Wandersee, James

2009-01-01

The study of polar exploration is fascinating and offers students insights into the history, culture, and politics that affect the developing sciences at the farthest ends of Earth. Therefore, the authors think there is value in incorporating polar exploration accounts within modern science classrooms, and so they conducted research to test their…

Marine polar steroids

International Nuclear Information System (INIS)

Stonik, Valentin A

2001-01-01

Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

Carbon nanotube fiber terahertz polarizer

Energy Technology Data Exchange (ETDEWEB)

Zubair, Ahmed [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Tsentalovich, Dmitri E.; Young, Colin C. [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Heimbeck, Martin S. [Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Everitt, Henry O. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Pasquali, Matteo [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

2016-04-04

Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ∼−30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2–1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

Polarized radio outbursts in BL Lacertae. I. Polarized emission from a compact jet. II. The flux and polarization of a piston-driven shock

International Nuclear Information System (INIS)

Aller, H.D.; Aller, M.F.; Hughes, P.A.

1985-01-01

A second highly polarized burst in BL Lacertae observed in 1983 which has very similar properties to the earlier burst in 1981-82 is described, and it is shown that in both bursts the electric vector of the polarized emission is nearly parallel to the observed extended structure. A weak shock, moving relativistically close to the line of sight, appears to be a very effective means of producing the observed behavior. A simple model is developed to represent the outbursts as due to a piston-driven shock which exhibits polarized emission due to compression of the otherwise random magnetic field of a collimated flow. It is shown that the general features of total flux, polarized flux, and polarization position angle as a function of frequency and time can be understood in terms of such a model. 34 references

The influence of charge and the distribution of charge in the polar region of phospholipids on the activity of UDP-glucuronosyltransferase.

Science.gov (United States)

Zakim, D; Eibl, H

1992-07-05

Studies of the mechanism of lipid-induced regulation of the microsomal enzyme UDP-glucuronosyltransferase have been extended by examining the influence of charge within the polar region on the ability of lipids to activate delipidated pure enzyme. The effects of net negative charge, of charge separation in phosphocholine, and of the distribution of charge in the polar region of lipids were studied using the GT2p isoform isolated from pig liver. Prior experiments have shown that lipids with net negative charge inhibit the enzyme (Zakim, D., Cantor, M., and Eibl, H. (1988) J. Biol. Chem. 263, 5164-5169). The current experiments show that the extent of inhibition on a molar basis increases as the net negative charge increases from -1 to -2. The inhibitory effect of negatively charged lipids is on the functional state of the enzyme and is not due to electrostatic repulsion of negatively charged substrates of the enzyme. Although the inhibitory effect of net negative charge is removed when negative charge is balanced by a positive charge due to a quaternary nitrogen, neutrality of the polar region is not a sufficient condition for activation of the enzyme. In addition to a balance of charge between Pi and the quaternary nitrogen, the distance between the negative and positive charges and the orientation of the dipole created by them are critical for activation of GT2p. The negative and positive charges must be separated by the equivalent of three -CH2- groups for optimal activation by a lipid. Shortening this distance by one -CH2- unit leads to a lipid that is ineffective in activating the enzyme. Reversal of the orientation of the dipole in which the negative charge is on the polymethylene side of the lipid-water interface and the positive charge extends into water also produces a lipid that is not effective for activating GT2p. On the other hand, lipids with phosphoserine as the polar region, which has the "normal" P-N distance but carries a net negative charge, do

Circular polarization analyzer with polarization tunable focusing of surface plasmon polaritons

Energy Technology Data Exchange (ETDEWEB)

Wang, Sen; Zhang, Yan, E-mail: yzhang@mail.cnu.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Wang, Xinke [Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Kan, Qiang [State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Qu, Shiliang [Optoelectronics Department, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

2015-12-14

A practical circular polarization analyzer (CPA) that can selectively focus surface plasmon polaritons (SPPs) at two separate locations, according to the helicity of the circularly polarized light, is designed and experimentally verified in the terahertz frequency range. The CPA consists of fishbone-slit units and is designed using the simulated annealing algorithm. By differentially detecting the intensities of the two SPPs focuses, the helicity of the incident circularly polarized light can be obtained and the CPA is less vulnerable to the noise of incident light. The proposed device may also have wide potential applications in chiral SPPs photonics and the analysis of chiral molecules in biology.

Optically Polarized Conduction-Band Electrons in Tungsten Observed by Spin-Polarized Photoemission

DEFF Research Database (Denmark)

Zürcher, P.; Meier, F.; Christensen, N. E.

1979-01-01

Along the (100) direction of tungsten, interband transitions induced by circularly polarized light of energy 1.5 eV......Along the (100) direction of tungsten, interband transitions induced by circularly polarized light of energy 1.5 eV...

Potencial de reúso de água na lavagem de caminhões utilizando Contator Biológico Rotativo

OpenAIRE

Subtil, Eduardo Lucas; Mierzwa, José Carlos; Hespanhol, Ivanildo; Rodrigues, Raphael

2016-01-01

Este estudo teve como objetivo avaliar o potencial de reúso de água na lavagem de caminhões a partir do efluente tratado por um Contator Biológico Rotativo operado em escala real. Para avaliação do potencial de reúso foi realizado um balanço de massa para o sistema de reúso levando em consideração a concentração de Sólidos Dissolvidos Totais como contaminante crítico. O sistema de tratamento produziu um efluente com concentrações médias de cor, turbidez, SDT e DBO5 de 45 ± 14 uC, 15 ± 6,0 NTU...

Polarization and ellipticity of high-order harmonics from aligned molecules generated by linearly polarized intense laser pulses

International Nuclear Information System (INIS)

Le, Anh-Thu; Lin, C. D.; Lucchese, R. R.

2010-01-01

We present theoretical calculations for polarization and ellipticity of high-order harmonics from aligned N 2 , CO 2 , and O 2 molecules generated by linearly polarized lasers. Within the rescattering model, the two polarization amplitudes of the harmonics are determined by the photo-recombination amplitudes for photons emitted with polarization parallel or perpendicular to the direction of the same returning electron wave packet. Our results show clear species-dependent polarization states, in excellent agreement with experiments. We further note that the measured polarization ellipse of the harmonic furnishes the needed parameters for a 'complete' experiment in molecules.

Multiband Circular Polarizer Based on Fission Transmission of Linearly Polarized Wave for X-Band Applications

Directory of Open Access Journals (Sweden)

Farman Ali Mangi

2016-01-01

Full Text Available A multiband circular polarizer based on fission transmission of linearly polarized wave for x-band application is proposed, which is constructed of 2 × 2 metallic strips array. The linear-to-circular polarization conversion is obtained by decomposing the linearly incident x-polarized wave into two orthogonal vector components of equal amplitude and 90° phase difference between them. The innovative approach of “fission transmission of linear-to-circular polarized wave” is firstly introduced to obtain giant circular dichroism based on decomposition of orthogonal vector components through the structure. It means that the incident linearly polarized wave is converted into two orthogonal components through lower printed metallic strips layer and two transmitted waves impinge on the upper printed strips layer to convert into four orthogonal vector components at the end of structure. This projection and transmission sequence of orthogonal components sustain the chain transmission of electromagnetic wave and can achieve giant circular dichroism. Theoretical analysis and microwave experiments are presented to validate the performance of the structure. The measured results are in good agreement with simulation results. In addition, the proposed circular polarizer exhibits the optimal performance with respect to the normal incidence. The right handed circularly polarized wave is emitted ranging from 10.08 GHz to 10.53 GHz and 10.78 GHz to 11.12 GHz, while the left handed circular polarized wave is excited at 10.54 GHz–10.70 GHz and 11.13 GHz–11.14 GHz, respectively.

Measuring polarization dependent dispersion of non-polarizing beam splitter cubes with spectrally resolved white light interferometry

Science.gov (United States)

Csonti, K.; Hanyecz, V.; Mészáros, G.; Kovács, A. P.

2017-06-01

In this work we have measured the group-delay dispersion of an empty Michelson interferometer for s- and p-polarized light beams applying two different non-polarizing beam splitter cubes. The interference pattern appearing at the output of the interferometer was resolved with two different spectrometers. It was found that the group-delay dispersion of the empty interferometer depended on the polarization directions in case of both beam splitter cubes. The results were checked by inserting a glass plate in the sample arm of the interferometer and similar difference was obtained for the two polarization directions. These results show that to reach high precision, linearly polarized white light beam should be used and the residual dispersion of the empty interferometer should be measured at both polarization directions.

Polarized semi-inclusive deep-inelastic scattering on transversely and longitudinally polarized nucleons at HERMES

International Nuclear Information System (INIS)

Hommes, B.

2005-01-01

The HERMES experiment has measured double spin asymmetries in the cross section for deep-inelastic scattering of longitudinal polarized positrons off longitudinal polarized hydrogen and deuterium targets. From these asymmetries, based on inclusive and semi-inclusive measurements, polarized quark distributions were extracted as a function of x. Single-spin azimuthal asymmetries in semi-inclusive pion production were measured by the HERMES experiment for the first time, with a transversely polarized hydrogen target. Two different sine-dependencies were extracted which can be related to the quark transversity distribution h q 1 (x) and the Sivers function (Author)

Polarized X-Ray Emission from Magnetized Neutron Stars: Signature of Strong-Field Vacuum Polarization

Science.gov (United States)

Lai, Dong; Ho, Wynn C.

2003-08-01

In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

Optimization of incident EC wave polarization in real-time polarization scan experiments on LHD

International Nuclear Information System (INIS)

Tsujimura, Toru I.; Mizuno, Yoshinori; Makino, Ryohei

2016-01-01

Real-time polarization scan experiments were performed on the Large Helical Device (LHD) to search an optimal incident wave polarization for electron cyclotron resonance heating. The obtained optimal polarization state to maximize the power absorption to the LHD plasma is compared with the ray-tracing code that includes mode content analyses, which indicates that the calculated results are generally in good agreement with the experimental results. The analyses show that optimal coupling to plasma waves requires a fine adjustment for an incident wave polarization even for perpendicular injection due to the finite density profile and the magnetic shear at the peripheral region. (author)

Polarized x-ray emission from magnetized neutron stars: signature of strong-field vacuum polarization.

Science.gov (United States)

Lai, Dong; Ho, Wynn C G

2003-08-15

In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.