Science.gov

Sample records for principales sistemas antivirus

  1. Crispen's Five Antivirus Rules.

    ERIC Educational Resources Information Center

    Crispen, Patrick Douglas

    2000-01-01

    Explains five rules to protect computers from viruses. Highlights include commercial antivirus software programs and the need to upgrade them periodically (every year to 18 months); updating virus definitions at least weekly; scanning attached files from email with antivirus software before opening them; Microsoft Word macro protection; and the…

  2. Crispen's Five Antivirus Rules.

    ERIC Educational Resources Information Center

    Crispen, Patrick Douglas

    2000-01-01

    Explains five rules to protect computers from viruses. Highlights include commercial antivirus software programs and the need to upgrade them periodically (every year to 18 months); updating virus definitions at least weekly; scanning attached files from email with antivirus software before opening them; Microsoft Word macro protection; and the…

  3. Crispen's Five Antivirus Rules.

    ERIC Educational Resources Information Center

    Crispen, Patrick Douglas

    2000-01-01

    Provides rules for protecting computers from viruses, Trojan horses, or worms. Topics include purchasing commercial antivirus programs and keeping them updated; updating virus definitions weekly; precautions before opening attached files; macro virus protection in Microsoft Word; and precautions with executable files. (LRW)

  4. Impact of anti-virus software on computer virus dynamical behavior

    NASA Astrophysics Data System (ADS)

    Sun, Mei; Li, Dandan; Han, Dun; Jia, Changsheng

    2014-11-01

    The impact of anti-virus software on the spreading of computer virus is investigated via developing a mathematical model in this paper. Considering the anti-virus software may not be effective, as it may be an outdated version, and then the computers may be infected with a reduced incidence rate. According to the method of next generation matrix, the basic reproduction number is derived. By introducing appropriate Lyapunov function and the Routh stability criterion, acquiring the stability conditions of the virus-free equilibrium and virus equilibrium. The effect of anti-virus software and disconnecting rate on the spreading of virus are also analyzed. When combined with the numerical results, a set of suggestions are put forward for eradicating virus effectively.

  5. Effect of anti-virus software on infectious nodes in computer network: A mathematical model

    NASA Astrophysics Data System (ADS)

    Mishra, Bimal Kumar; Pandey, Samir Kumar

    2012-07-01

    An e-epidemic model of malicious codes in the computer network through vertical transmission is formulated. We have observed that if the basic reproduction number is less than unity, the infected proportion of computer nodes disappear and malicious codes die out and also the malicious codes-free equilibrium is globally asymptotically stable which leads to its eradication. Effect of anti-virus software on the removal of the malicious codes from the computer network is critically analyzed. Analysis and simulation results show some managerial insights that are helpful for the practice of anti-virus in information sharing networks.

  6. Coping with Computer Viruses: General Discussion and Review of Symantec Anti-Virus for the Macintosh.

    ERIC Educational Resources Information Center

    Primich, Tracy

    1992-01-01

    Discusses computer viruses that attack the Macintosh and describes Symantec AntiVirus for Macintosh (SAM), a commercial program designed to detect and eliminate viruses; sample screen displays are included. SAM is recommended for use in library settings as well as two public domain virus protection programs. (four references) (MES)

  7. Theoretical and experimental analysis of the impacts of removable storage media and antivirus software on viral spread

    NASA Astrophysics Data System (ADS)

    Gan, Chenquan; Yang, Xiaofan

    2015-05-01

    In this paper, a new computer virus propagation model, which incorporates the effects of removable storage media and antivirus software, is proposed and analyzed. The global stability of the unique equilibrium of the model is independent of system parameters. Numerical simulations not only verify this result, but also illustrate the influences of removable storage media and antivirus software on viral spread. On this basis, some applicable measures for suppressing virus prevalence are suggested.

  8. Toward Automatic Discovery of Malware Signature for Anti-Virus Cloud Computing

    NASA Astrophysics Data System (ADS)

    Yan, Wei; Wu, Erik

    Security vendors are facing a serious problem of defeating the complexity of malwares. With the popularity and the variety of zero-day malware over the Internet, generating their signatures for detecting via anti-virus (AV) scan engines becomes an important reactive security function. However, AV security products consume much of the PC memory and resources due to their large signature files. AV cloud computing becomes a popular solution for this problem. In this paper, a novel Automatic Malware Signature Discovery System for AV cloud (AMSDS) is proposed to generate malware signatures from both static and dynamic aspects. Our experiments on millions-scale samples suggest that AMSDS outperforms most state-of-the-art automatic signature generation techniques of both industry and academia.

  9. Personal computer security: part 1. Firewalls, antivirus software, and Internet security suites.

    PubMed

    Caruso, Ronald D

    2003-01-01

    Personal computer (PC) security in the era of the Health Insurance Portability and Accountability Act of 1996 (HIPAA) involves two interrelated elements: safeguarding the basic computer system itself and protecting the information it contains and transmits, including personal files. HIPAA regulations have toughened the requirements for securing patient information, requiring every radiologist with such data to take further precautions. Security starts with physically securing the computer. Account passwords and a password-protected screen saver should also be set up. A modern antivirus program can easily be installed and configured. File scanning and updating of virus definitions are simple processes that can largely be automated and should be performed at least weekly. A software firewall is also essential for protection from outside intrusion, and an inexpensive hardware firewall can provide yet another layer of protection. An Internet security suite yields additional safety. Regular updating of the security features of installed programs is important. Obtaining a moderate degree of PC safety and security is somewhat inconvenient but is necessary and well worth the effort. PMID:12975519

  10. Anti-tumor and anti-virus activity of polysaccharides extracted from Sipunculus nudus(SNP) on Hepg2.2.15.

    PubMed

    Su, Jie; Jiang, Linlin; Wu, Jingna; Liu, Zhiyu; Wu, Yuping

    2016-06-01

    Many polysaccharides have biological activities and have been investigated for their antitumor effects. In this study, we investigated the anti-tumor activity and anti-virus activity of SNP-the water-soluble polysaccharides extracted from Sipunculus nudus on Hepg2.2.15. Flow cytometry analysis demonstrated that SNP induced dose-dependent cell apoptosis on Hepg2.2.15. Real-time PCR and Western Blot analysis showed that SNP down-regulated the synthesis of HBsAg, HBV-DNA and enhanced the expression of pro-apoptosis proteins TNF-α, caspase-3, and Bax, while decreasing the expression of the anti-apoptosis proteins survivin, Bcl-2, and VEGF. These results suggested that SNP suppressed cell viability of Hepg2.2.15 and that could be a novel anti-tumor and anti-HBV agent. PMID:26987430

  11. Effect of various absorption enhancers based on tight junctions on the intestinal absorption of forsythoside A in Shuang-Huang-Lian, application to its antivirus activity

    PubMed Central

    Zhou, Wei; Zhu, Xuan Xuan; Yin, Ai Ling; Cai, Bao Chang; Wang, Hai Dan; Di, Liuqing; Shan, Jin Jun

    2014-01-01

    Background: Forsythoside A (FTA), one of the main active ingredients in Shuang–Huang–Lian (SHL), possesses strong antibacterial, antioxidant and antiviral effects, and its pharmacological effects was higher than that of other ingredients, but the absolute bioavailability orally was approximately 0.72%, which was significantly low, influencing clinical efficacies of its oral preparations seriously. Materials and Methods: In vitro Caco-2 cell and in vivo pharmacokinetics study were simultaneously performed to investigate the effects of absorption enhancers based on tight junctions: sodium caprate and water-soluble chitosan on the intestinal absorption of FTA, and the eventual mucosal epithelial damage resulted from absorption enhancers was evaluated by MTT test and morphology observation, respectively. The pharmacological effects such as antivirus activity improvement by absorption enhancers were verified by MDCK damage inhibition rate after influenza virus propagation. Results: The observations from in vitro Caco-2 cell showed that the absorption of FTA in SHL could be improved by absorption enhancers. Meanwhile, the absorption enhancing effect of water-soluble chitosan may be almost saturable up to 0.0032% (w/v), and sodium caprate at concentrations up to 0.64 mg/mL was safe, but water-soluble chitosan at different concentrations was all safe for these cells. In pharmacokinetics study, water-soluble chitosan at dosage of 50 mg/kg improved the bioavailability of FTA in SHL to the greatest extent, and was safe for gastrointestine from morphological observation. Besides, treatment with SHL with water-soluble chitosan at dosage of 50 mg/kg prevented MDCK damage after influenza virus propagation better significantly than that of control. Conclusion: Water-soluble chitosan at dosage of 50 mg/kg might be safe and effective absorption enhancer for improving the bioavailability of FTA and the antivirus activity in vitro in SHL. PMID:24695554

  12. Sequence analyses of three immunoglobulin G anti-virus antibodies reveal their utilization of autoantibody-related immunoglobulin Vh genes, but not V lambda genes.

    PubMed

    Huang, D F; Olee, T; Masuho, Y; Matsumoto, Y; Carson, D A; Chen, P P

    1992-12-01

    Accumulated sequence analyses of the antibody repertoire have revealed that most autoantibodies and developmentally regulated antibodies share a small set of germline Ig-variable region (V) genes. The findings have prompted speculation that certain autoantibodies are of developmental importance and may be instrumental in maintaining homeostasis of the adult antibody repertoire. In order to evaluate this hypothesis critically, it is first necessary to determine the V gene usage in human antibodies against foreign substances. Unfortunately, only a few such antibodies have had their heavy and light chains characterized. To rectify the situation, we adapted the anchored polymerase chain reaction to clone and analyze rapidly the expressed V genes for three anti-virus IgG antibodies. The results show that all three heavy chain V (Vh) genes are highly homologous to the known autoantibody-related Vh genes. In contrast, two light chain V (VL) genes of the V lambda 1 subgroup are similar to a non-autoantibody-related germline V lambda 1 gene. Taken together with the reported Vh and VL sequences of several antibodies against viruses and bacteria, the data show that many antipathogen antibodies may use the same small set of Vh genes that encode autoantibodies, but diverse VL genes that are distinct from autoantibody-related VL genes. Thus, only a small portion of the potentially functional germline Vh genes are used recurrently to generate most antibodies in a normal antibody repertoire, regardless of their reactivities with either self or non-self. PMID:1334971

  13. El Sistema's Open Secrets

    ERIC Educational Resources Information Center

    Booth, Eric

    2011-01-01

    In this article, the author talks about Venezuela's national youth orchestra program called El Sistema whose attributes offer a direct challenge to traditional Western music practices. As U.S. classical music--and all "high arts"--struggle to find relevance to more than the small "arts club" percentage of the U.S. populace, El Sistema proposes…

  14. El Sistema's Open Secrets

    ERIC Educational Resources Information Center

    Booth, Eric

    2011-01-01

    In this article, the author talks about Venezuela's national youth orchestra program called El Sistema whose attributes offer a direct challenge to traditional Western music practices. As U.S. classical music--and all "high arts"--struggle to find relevance to more than the small "arts club" percentage of the U.S. populace, El Sistema proposes…

  15. Knowledge Exchange with Sistema Scotland

    ERIC Educational Resources Information Center

    Allan, Julie; Moran, Nikki; Duffy, Celia; Loening, Gica

    2010-01-01

    This paper reports on a knowledge exchange project, funded by the Scottish Funding Council and undertaken by a group of researchers from three higher education institutions in Scotland and the project partner, Sistema Scotland. This newly established charity is attempting to implement a major programme of social change, developed in Venezuela,…

  16. Thoughts on Seeing "El Sistema"

    ERIC Educational Resources Information Center

    Booth, Eric

    2009-01-01

    The FESNOJIV (the Spanish acronym for the State Foundation for the National System of Youth and Children's Orchestras), more commonly known as "El Sistema," teaches 300,000 of Venezuela's poorest children in the nationwide music learning program. Many begin attending the "nucleo" as early as age two or three, and the vast majority continue well…

  17. Obstáculos a la adherencia y retención en los sistemas de salud público y privado según pacientes y personal de salud

    PubMed Central

    Arístegui, Inés; Dorigo, Analía; Bofill, Lina; Bordatto, Alejandra; Lucas, Mar; Cabanillas, Graciela Fernández; Sued, Omar; Cahn, Pedro; Cassetti, Isabel; Weiss, Stephen; Jones., Deborah

    2016-01-01

    Resumen Introducción el Programa Nacional de Sida garantiza el acceso universal a los antirretrovirales, aun así las personas que reciben medicamentos a través del sistema público no logran obtener una carga viral indetectable en la misma proporción que los pacientes del sistema privado. Este estudio cualitativo tiene como objeto identificar los factores asociados a la adherencia y retención en la cascada de atención de VIH de los sistemas de salud público y privado de Buenos Aires, según las percepciones de pacientes y del personal de salud. Métodos se registraron datos cualitativos de 12 entrevistas semi-estructuradas a informantes clave y 4 grupos focales de pacientes y personal de salud tanto del sistema público como privado. Se codificaron y analizaron temas predeterminados sobre adherencia, utilizando el software QRS Nvivo9® de análisis de datos cualitativos. Resultados pacientes y personal de salud de ambos sistemas coinciden en la importancia del estigma asociado al VIH, la relación médicopaciente, la comunicación entre ambos y la división de responsabilidades en relación al tratamiento como aspectos fundamentales para la adherencia y retención en la cascada de atención. Se observan diferencias entre los sistemas en la forma en que algunos de estos aspectos actúan. Las barreras estructurales se presentan como principales obstáculos del sistema público. Discusión se resalta la necesidad de intervenciones focalizadas en la díada médico-paciente que considere las particularidades de cada sistema de atención para facilitar el compromiso del paciente en la adherencia. PMID:26878024

  18. El Sistema and American Music Education

    ERIC Educational Resources Information Center

    Lesniak, Melissa

    2012-01-01

    The brainchild of Jose Antonio Abreu, El Sistema, a music education program for aspiring orchestra musicians launched in Venezuela for students of limited means and now spreading to other parts of the world, has become a subject of interest to music teachers and teacher educators in North America. This article examines a bit of the program's…

  19. El Sistema and American Music Education

    ERIC Educational Resources Information Center

    Lesniak, Melissa

    2012-01-01

    The brainchild of Jose Antonio Abreu, El Sistema, a music education program for aspiring orchestra musicians launched in Venezuela for students of limited means and now spreading to other parts of the world, has become a subject of interest to music teachers and teacher educators in North America. This article examines a bit of the program's…

  20. Caos en sistemas clásico-cuánticos

    NASA Astrophysics Data System (ADS)

    Dirani, L. D.; Núñez, J. A.

    Una de las formas de estudiar la existencia de caos en el comportamiento de un sistema clásico-cuántico, es truncando el espacio de Hilbert del sistema cuántico. El objetivo de este trabajo es analizar como afecta dicho truncamiento en la dinámica del sistema. Para tal fin se propone un Hamiltoniano integrable, cuyos valores de expectación asociados a coordenadas y momentos cuánticos responden, por el teorema de Ehrenfest, a un sistema de dos osciladores clásicos con acoplamiento lineal.

  1. Evolución estelar en sistemas binarios

    NASA Astrophysics Data System (ADS)

    De Vito, M. A.; Benvenuto, O.

    Definición y clasificación de sistemas binarios; descripción del comportamiento del sistema frente a la variación de su masa; binarias de rayos X; transferencia de masa en sistemas binarios masivos aplicado al posible esclarecimiento del progenitor azul de la supernova SN 1987A; comentario acerca de la evolución de enanas blancas de helio de baja masa y su conexión con los sistemas binarios; reseña del trabajo de Kippenhahn y Weigert sobre el cual está basado el código evolutivo desarrollado en la FCAG por el Dr. Benvenuto y sobre el cual se trabajará para poder incluir la evolución de una estrella con pérdida de masa perteneciente a un sistema binario.

  2. Sistemas de cúmulos globulares extragalácticos

    NASA Astrophysics Data System (ADS)

    Forte, J. C.

    Se describen las características de los sistemas de cúmulos globulares asociados a galaxias elípticas en una variedad de medios y, en particular, aquellas vinculadas con la distribución espacial, frecuencia específica y composición química. Esta discusión se hace dentro de un conjunto de esquemas orientados a explicar las primeras fases de la formación de las galaxias dominantes en cúmulos y del rol de los sistemas de cúmulos globulares en esos procesos.

  3. Sistemas Correctores de Campo Para EL Telescopio Cassegrain IAC80

    NASA Astrophysics Data System (ADS)

    Galan, M. J.; Cobos, F. J.

    1987-05-01

    El proyecto de instrumentación de mayor importancia que ha tenido el Instituto de Astrofisica de Canarias en los últimos afios ha sido el diseflo y construcción del te1escopio IAC8O. Este requería del esfuerzo con junto en mec´nica, óptica y electrónica, lo que facilitó la estructuración y el crecimiento de los respectivos grupos de trabajo, que posteriormente se integraron en departamentos En su origen (1977), el telescopio IAC80 fue concebido como un sistema clásico tipo Cassegrain, con una razón focal F/i 1.3 para el sistema Casse grain y una razón focal F/20 para el sistema Coudé. Posteriormente, aunque se mantuvo la filosofia de que el sistema básico fuera el F/11.3, se consideró conveniente el diseño de secundarios para razones focales F/16 y F/32, y se eliminó el de F/20. Sin embargo, dada la importancia relativa que un foco estrictamente fotográfico tiene en un telescopio moderno, diseñado básicamente para fotometría fotoeléctrica y con un campo util mínimamente de 40 minutos de arco, se decídió Ilevar a cabo el diseño de un secundario F/8 con un sistema corrector de campo, pero que estuviera formado únicamente por lentes con superficies esféricas para que asl su construcción fuera posible en España ó en México. La creciente utilización de detectores bidimensionales para fines de investigación astron6mica y la viabilidad de que en un futuro cercano éstos tengan un área sensible cada vez mayor, hicieron atractiva la idea de tener diseñado un sistema corrector de campo para el foco primario (F/3), con un campo útil mínimo de un grado, y también con la limitante de que sus componentes tuvieron sólamente supérficies esféricas. Ambos diseños de los sis-temas correctores de campo se llevaron a cabo, en gran medida, como parte de un proyecto de colaboración e intercambio en el área de diseño y evaluación de sistemas ópticos.

  4. El problema de estabilidad de los sistemas Hamiltonianos multidimensionales

    NASA Astrophysics Data System (ADS)

    Cincotta, P. M.

    Se revisarán los aspectos básicos del problema de estabilidad de sistemans Hamiltonianos N-dimensionales, haciendo especial énfasis en los posibles mecanismos que dan lugar a la aparición de ``caos": overlap de resonancias, difusión de Arnol'd y otros procesos difusivos alternativos. Se mencionarán los aspectos aún no resueltos sobre la estabilidad de los sistemas con N > 2. Finalmente, se discutirá cuáles de estos mecanismos podrían tener alguna relevancia en la dinámica de sistemas estelares y planetarios.

  5. The Story of Carora: The Origins of El Sistema

    ERIC Educational Resources Information Center

    Carlson, Alexandra

    2016-01-01

    Venezuela's youth symphony program, the Fundación Musical Simón Bolívar, commonly referred to as "El Sistema," combines musical achievement with learning important life skills through orchestral practice and performance. Although the history most commonly reported outside Venezuela is of the program's director, José Antonio Abreu,…

  6. The Story of Carora: The Origins of El Sistema

    ERIC Educational Resources Information Center

    Carlson, Alexandra

    2016-01-01

    Venezuela's youth symphony program, the Fundación Musical Simón Bolívar, commonly referred to as "El Sistema," combines musical achievement with learning important life skills through orchestral practice and performance. Although the history most commonly reported outside Venezuela is of the program's director, José Antonio Abreu,…

  7. El Sistema de Referencia Celeste convencional de la IAU

    NASA Astrophysics Data System (ADS)

    Arias, E. F.

    La Unión Astronómica Internacional (IAU) recomendó la adopción de un nuevo sistema de referencia celeste baricéntrico cuyo plano fundamental y origen de ascensiones rectas estén próximos, respectivamente, al ecuador y equinoccio dinámicos J2000.0. El nuevo sistema de referencia estará materializado por las posiciones J2000.0 de radiofuentes extragalácticas determinadas con la técnica de interferometría de larga línea de base (VLBI). El Working Group on Reference Frames de la IAU (WGRF) decidió adoptar (Grasse, 1995) al sistema de referencia celeste extragaláctico del Servicio Internacional de la Rotación Terrestre (IERS) como futuro sistema de referencia celeste convencional bajo el nombre International Celestial Reference System (ICRS) y encomendó su mantenimiento futuro al IERS. El marco de referencia que materializará al ICRS contiene posiciones precisas J2000.0 de más de 600 radiofuentes extragalácticas. Las coordenadas fueron ajustadas en una única solución VLBI en la cual se incluyeron todas las observaciones realizadas hasta octubre de 1995 con la técnica de adquisición de datos VLBI Mark III. Para minimizar los errores sistemáticos que pueden afectar la calidad del marco de referencia se introdujeron mejoras sustanciales en la modelización y en la selección de datos. Un subconjunto de objetos del marco de referencia se utilizó para referir las posiciones estelares determinadas con el satélite astrométrico Hipparcos al ICRS.

  8. Lifting the Veil: A Realist Critique of Sistema's Upwardly Mobile Path

    ERIC Educational Resources Information Center

    Logan, Owen

    2016-01-01

    El Sistema sits somewhere between a social project and a classical music initiative. However, its promise of delivering upward mobility has not been sufficiently examined as a structural phenomenon which dovetails with critical policy issues in taxation, educational provision, human rights, and welfare. This article argues that Sistema-style…

  9. Hatching Plans: Pedagogy and Discourse within an El Sistema-Inspired Music Program

    ERIC Educational Resources Information Center

    Dobson, Nicolas

    2016-01-01

    In this article, I draw on my experience as an instrumental tutor with a music program inspired by and explicitly linked to El Sistema, to explore new perspectives on Sistema-based pedagogy and management. Detailed ethnographic description of an orchestral session provides a first-hand account of the program's pedagogy, which I then contextualize…

  10. Resurrection Symphony: "El Sistema" as Ideology in Venezuela and Los Angeles

    ERIC Educational Resources Information Center

    Fink, Robert

    2016-01-01

    The explosive growth of Venezuela's "El Sistema" is rewriting the agenda of musical education in the West. Many commentators from the world of classical music react to the spectacle of dedicated young colonial musicians playing European masterworks as a kind of "miracle," accepting "Sistema" founder José Antonio…

  11. Resurrection Symphony: "El Sistema" as Ideology in Venezuela and Los Angeles

    ERIC Educational Resources Information Center

    Fink, Robert

    2016-01-01

    The explosive growth of Venezuela's "El Sistema" is rewriting the agenda of musical education in the West. Many commentators from the world of classical music react to the spectacle of dedicated young colonial musicians playing European masterworks as a kind of "miracle," accepting "Sistema" founder José Antonio…

  12. Characterization and antivirus activities of a novel bovine IFN-omega24.

    PubMed

    Luo, Xiuxin; Guo, Yongli; Bao, Jun; Liu, Ying; An, Dong; Ma, Bo; Gao, Mingchun; Wang, Junwei

    2015-08-01

    A novel bovine interferon-ω (BoIFN-ω) gene, which encodes a protein of 195 amino acids with a 23-amino acid signal peptide, was amplified from bovine liver genomic DNA through PCR and named BoIFN-ω24 according to its position in the bovine genome. In this study, the recombinant protein was expressed in Escherichia coli and antiviral or antiproliferation activity was determined in vitro. Results showed that BoIFN-ω24 exhibits high antiviral activity, which can be abrogated using PAb against BoIFN-ω24, and inhibits cell proliferation. BoIFN-ω24 also presents high sensitivity to trypsin and stability at pH 2.0 or 65°C, which are typical characteristics of type I IFN. This study revealed that BoIFN-ω24 is a potential novel effective therapeutic agent and provided a basis for further research on the BoIFN-ω multigene family. PMID:25951414

  13. Estudio del sistema simbiótico AR Pavonis

    NASA Astrophysics Data System (ADS)

    Quiroga, C.; Brandi, E.; Ferrer, O.; García, L.; Barbá, R.

    Se presenta un estudio espectroscópico y polarimétrico de la binaria eclipsante AR Pavonis a partir de observaciones obtenidas con el telescopio de 2.15 m. del CASLEO (San Juan). El estudio de la naturaleza del sistema se realizó a través del análisis de algunos espectros reunidos entre los años 1990 y 1995 y de datos polarimétricos correspondientes al intervalo 1995 y 1997. El análisis espectroscópico indica que AR Pav está compuesta por una gigante roja M3.7 y una componente caliente compacta, con una temperatura mayor a 90000 K y una luminosidad del orden de 500Lsolar. A lo largo del período orbital, las variaciones observadas en flujo y en velocidades radiales, reflejan que las emisiones permitidas se forman en una región que rodea la componente caliente. El estudio de la polarización lineal de AR Pav indica que además de una componente interestelar, existe una componente intrínseca del sistema que varía temporalmente y con la longitud de onda de la luz polarizada. El distinto comportamiento del grado de polarización y del ángulo de posición observado en fases diferentes, sugiere que distintos mecanismos pueden estar actuando, dependiendo de la región de scattering observado a lo largo de la línea de la visual.

  14. Things to Remember about El Sistema: A Response to "El Sistema--A Perspective for North American Music Educators" by Tricia Tunstall

    ERIC Educational Resources Information Center

    Lesniak, Melissa

    2013-01-01

    Melissa Lesniak, the executive director of the Greater Miami Youth Symphony, discusses how much she enjoyed reading the responses to her "El Sistema" article and appreciates the opportunity for healthy dialogue and debate. In response, she states that there are many common goals and objectives across all music education programs that can…

  15. Things to Remember about El Sistema: A Response to "El Sistema--A Perspective for North American Music Educators" by Tricia Tunstall

    ERIC Educational Resources Information Center

    Lesniak, Melissa

    2013-01-01

    Melissa Lesniak, the executive director of the Greater Miami Youth Symphony, discusses how much she enjoyed reading the responses to her "El Sistema" article and appreciates the opportunity for healthy dialogue and debate. In response, she states that there are many common goals and objectives across all music education programs that can…

  16. "The Feelings Have Come Home to Me." Examining Advertising Films on the Swedish Website of El Sistema

    ERIC Educational Resources Information Center

    Kuuse, Anna-Karin; Lindgren, Monica; Skåreus, Eva

    2016-01-01

    The purpose of this study is to analyze how the music educational program of El Sistema Sweden is advertised and legitimized through moving images. The films are a major part of the information on the Swedish national website of El Sistema and are supposed to contribute to the picture that the organization and its founders wish to market. The use…

  17. "The Feelings Have Come Home to Me." Examining Advertising Films on the Swedish Website of El Sistema

    ERIC Educational Resources Information Center

    Kuuse, Anna-Karin; Lindgren, Monica; Skåreus, Eva

    2016-01-01

    The purpose of this study is to analyze how the music educational program of El Sistema Sweden is advertised and legitimized through moving images. The films are a major part of the information on the Swedish national website of El Sistema and are supposed to contribute to the picture that the organization and its founders wish to market. The use…

  18. Another Perspective: El Sistema--A Perspective for North American Music Educators

    ERIC Educational Resources Information Center

    Tunstall, Tricia

    2013-01-01

    Herein, Tricia Tunstall presents a critique of the article by Melissa Lesniak published in the December 2012 "Music Educators Journal," and offers a new perspective on the Venezuelan youth orchestra program known as "El Sistema." The program, which began in Caracas thirty-eight years ago, is dedicated to changing the lives of…

  19. El Sistema de Formas en Colores for Teaching Grammar in Spanish

    ERIC Educational Resources Information Center

    Nailon, James

    2010-01-01

    Sistema de formas en colores (SFC) is a symbols-based system for teaching Spanish grammatical structures and concepts within a communicative context in the elementary school. The (ACTFL) Standards for Foreign Language Learning: Preparing for the 21st Century states that, "While grammar and vocabulary are essential tools for communication, it is…

  20. Five Encounters with "El Sistema" International: A Venezuelan Marvel Becomes a Global Movement

    ERIC Educational Resources Information Center

    Booth, Eric; Tunstall, Tricia

    2014-01-01

    Genuine worldwide movements for social change are rare in human history. Even more rare is the phenomenon of a worldwide movement for social change through art, with teaching artists at the forefront. This article presents the evolution of such a movement now, in the global blossoming of "El Sistema," a program that seeks to change the…

  1. Exploración del Sistema Solar -- Una mirada hacia el futuro - Duration: 30 seconds.

    NASA Video Gallery

    ¿Piensas que ya sabemos todo acerca de nuestro sistema solar? La realidad es que apenas hemos comenzado con lo que hay para conocer. Únete a la NASA, en el envío de misiones a los confines del sist...

  2. El Sistema as a Bourgeois Social Project: Class, Gender, and Victorian Values

    ERIC Educational Resources Information Center

    Bull, Anna

    2016-01-01

    This article asks why classical music in the UK, which is consumed and practiced by the middle and upper classes, is being used as a social action program for working-class children in British music education schemes inspired by El Sistema. Through exploring the discourse of the social benefits of classical music in the late nineteenth century, a…

  3. Another Perspective: El Sistema--A Perspective for North American Music Educators

    ERIC Educational Resources Information Center

    Tunstall, Tricia

    2013-01-01

    Herein, Tricia Tunstall presents a critique of the article by Melissa Lesniak published in the December 2012 "Music Educators Journal," and offers a new perspective on the Venezuelan youth orchestra program known as "El Sistema." The program, which began in Caracas thirty-eight years ago, is dedicated to changing the lives of…

  4. El Sistema as a Bourgeois Social Project: Class, Gender, and Victorian Values

    ERIC Educational Resources Information Center

    Bull, Anna

    2016-01-01

    This article asks why classical music in the UK, which is consumed and practiced by the middle and upper classes, is being used as a social action program for working-class children in British music education schemes inspired by El Sistema. Through exploring the discourse of the social benefits of classical music in the late nineteenth century, a…

  5. El Sistema de Formas en Colores for Teaching Grammar in Spanish

    ERIC Educational Resources Information Center

    Nailon, James

    2010-01-01

    Sistema de formas en colores (SFC) is a symbols-based system for teaching Spanish grammatical structures and concepts within a communicative context in the elementary school. The (ACTFL) Standards for Foreign Language Learning: Preparing for the 21st Century states that, "While grammar and vocabulary are essential tools for communication, it is…

  6. Improving Middle School Quality in Poor Countries: Evidence from the Honduran "Sistema De Aprendizaje Tutorial"

    ERIC Educational Resources Information Center

    McEwan, Patrick J.; Murphy-Graham, Erin; Torres Irribarra, David; Aguilar, Claudia; Rápalo, Renán

    2015-01-01

    This article evaluates the impact and cost-effectiveness of offering an innovative middle school model--the Sistema de Aprendizaje Tutorial (SAT)--to Honduran villages instead of traditional middle schools. We identified a matched sample of villages with either type of school and collected baseline data among primary school graduates eligible to…

  7. Social Responsibility and Community Development: Lessons from the Sistema de Aprendizaje Tutorial in Honduras

    ERIC Educational Resources Information Center

    Honeyman, Catherine A.

    2010-01-01

    This article extends understanding of the connections between education, social capital, and development through a mixed-methods case study of the Sistema de Aprendizaje Tutorial, or SAT, an innovative secondary-level education system. The quantitative dimension of the research used survey measures of social responsibility to compare 93 SAT…

  8. Sistema Planeta-Satélite. Simulación orbital y potenciales gravitatorios

    NASA Astrophysics Data System (ADS)

    Medina, C.; Carrillo, M.

    Se presenta un programa (desarrollado en Quick Basic 4.5) que simula, en tres dimensiones, el movimiento orbital de un satélite (o luna) alrededor de un planeta, al tiempo que calcula y grafica, en un plano, el potencial gravitatorio del sistema en función de la distancia al planeta. Para la simulación orbital, se emplea la matriz de transformación entre el sistema del planeta y el plano orbital. Para el cálculo y graficación del potencial se aplica un desarrollo en serie hasta el segundo orden, que da cuenta del efecto de achatamiento de los polos, en caso de que éste exista. Las longitudes de los ejes del planeta, la masa de éste y del satélite, sus tamaños aparentes, y los parámetros orbitales son introducidos por el usuario.

  9. Discos de acresção em sistemas Be-X

    NASA Astrophysics Data System (ADS)

    Lopes de Oliveira, R.; Janot-Pacheco, E.

    2003-08-01

    Alguns fenômenos de outbursts em Be-X sugerem a existência, mesmo que temporária, de um disco de acresção quando da passagem do objeto compacto pelo periastro orbital. Neste trabalho avaliamos a possibilidade de formação do disco de acresção em sistemas Be+estrela de neutrons e Be+anã branca, e a influência da excentricidade orbital na ocorrência deste fenômeno. Utilizamos a expressão analítica para o momento angular específico da matéria constituinte de um meio em expansão lenta, como é o caso do disco circunstelar das estrelas Be, proposta por Wang(1981), sob a condição básica de que o raio de circularização deva ser maior do que o raio de Alfvén. Concluímos que existe um limite para o período orbital do sistema acima do qual não é possível a formação do disco de acresção, e que este valor aumenta para sistemas com excentricidade orbital maior.

  10. Securing PCs and Data in Libraries and Schools: A Handbook with Menuing, Anti-Virus, and Other Protective Software.

    ERIC Educational Resources Information Center

    Benson, Allen C.

    This handbook is designed to help readers identify and eliminate security risks, with sound recommendations and library-tested security software. Chapter 1 "Managing Your Facilities and Assessing Your Risks" addresses fundamental management responsibilities including planning for a secure system, organizing computer-related information, assessing…

  11. Evaluation of Spirulina platensis extract as natural antivirus against foot and mouth disease virus strains (A, O, SAT2)

    PubMed Central

    Daoud, Hind M.; Soliman, Eman M.

    2015-01-01

    Aim: This work was aimed to document the antiviral activates of Spirulina platensis extract against foot and mouth disease virus (FMDV) different types to evaluate its replication in Baby Hamster Kidney (BHK) cell culture and in baby mice. Materials and Methods: Cytotoxicity assay studied for S. platensis extract on BHK cells to determine the non-toxic dose. The non-toxic dose of Spirulina extract was mixed with each type of FMDV (A, O, SAT2). Then 10-fold dilutions from each mixture were done. FMDV titer for each type of treated FMDV was calculated to evaluate the antiviral activity of the Spirulina extract against FMDV. Furthermore, old baby Swiss mice were inoculated with 0.1 ml intraperitonially from the mixture of FMDV different types and different concentration of Spirulina extracts. After 48 h post inoculation, all the baby mice examined to evaluate the antiviral action of Spirulina extract. Results: The result showed that the non-toxic doses of S. platensis (50 ug/ml) revealed 35.7%, 28.5%, and 31% reductions in FMDV titers Type O, A, and SAT2 on BHK cells, respectively. The same non-toxic dose gave 50% of the inhibitory concentration in baby mice without cytotoxic effect. Conclusion: This study confirmed the biological activity of the ethanol extract of S. platensis against FMDV Types O, A, and SAT2. From the results, S. platensis could be useful as antiviral lead to limitation of infection among animals during outbreaks but further studies need to evaluate the S. platensis on experimental or natural infected farm animals to establish the effective dose side affected period of treatment of S. platensis. PMID:27047027

  12. Securing PCs and Data in Libraries and Schools: A Handbook with Menuing, Anti-Virus, and Other Protective Software.

    ERIC Educational Resources Information Center

    Benson, Allen C.

    This handbook is designed to help readers identify and eliminate security risks, with sound recommendations and library-tested security software. Chapter 1 "Managing Your Facilities and Assessing Your Risks" addresses fundamental management responsibilities including planning for a secure system, organizing computer-related information, assessing…

  13. Sistemas Correctores de Campo Para EL Telescopio Ritchey-Chretien UNAM212

    NASA Astrophysics Data System (ADS)

    Cobos, F. J.; Galan, M. J.

    1987-05-01

    El telescopio UNAM2l2 fue inaugurado hace siete años y concebido para trabajar en las razones focales: f/7.5, F/13.5, F/27 y F/98. El diseño Ritchey-Chretién corresponde a la razón focal F/7.5 y el foco primario (F/2.286) no se consideró como utilizable para fotografía directa. En el Instituto de Astronomía de la UNAM, se diseñó y construyó un sistema corrector de campo para la razón focal F/7.5, que actualmente está en funcionamiento. Dentro de un programa de colaboración en diseflo y evaluación de sistemas ópticos, entre el Instituto de Astrofísica de Canarias y el Instituto de Astronomía de la UNAM, decidimos intentar el diseño de una correctora de campo para el foco primario del t?lescopio UNAM212 bajo la consideración de que no son insalvables los problemas que implicaría su instalación y de que es muy posible que, en un futuro relativamente cercano, podamom tener un detector bidimenmional tipo Mepsicrón cuya área sensible haga tentadora la idea de construir la cámara directa para foco primario

  14. Instantánea de los cánceres de cerebro y del sistema nervioso central

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre los cánceres de cerebro y del sistema nervioso central; así como ejemplos de actividades del NCI y adelantos en la investigación de estos tipos de cáncer.

  15. From the model of El Sistema in Venezuela to current applications: learning and integration through collective music education.

    PubMed

    Majno, Maria

    2012-04-01

    Over the last years, El Sistema--the Venezuelan project started in 1975 and now acknowledged worldwide as the most significant example of collective music education--has inspired a profusion of remarkable initiatives on all continents. From the original impulse by founder José Antonio Abreu, strong social principles of integration are combined with specific musical approaches to achieve individual empowerment as a large-scale alternative to endemic juvenile crime, counteracting the risk factors of social unease, serving as a stimulating example toward emancipation, and providing professional opportunities to the talented. Such a network, in turn, proves to be a powerful instrument of cultural progress: the tenets of "Sistema" become shared values able to foster development, reaching into issues of disability and rehabilitation. This paper presents continuities and contrasts in various ramifications of such a successful trend and outlines perspectives for further impact of this powerful transformational agent. PMID:22524340

  16. Calibração do sistema imageador do telescópio MASCO

    NASA Astrophysics Data System (ADS)

    Mejía, J.; D'Amico, F.; Villela, T.; Braga, J.

    2003-08-01

    O MASCO (MÁScara COdificada) é um telescópio imageador de raios-X e gama atualmente configurado para operar na faixa de 50 a 600 keV com uma resolução angular de 14 minutos de arco num campo de visada total circular de 23,5° de diâmetro. O MASCO está totalmente operacional e deverá ser lançado em um balão estratosférico no segundo semestre de 2003 para realizar observações durante ~20 horas a ~40 km de altitude. O telescópio utiliza uma máscara codificada de padrão uniformemente redundante modificado (MURA) de dimensões 19 ´ 19. Esse padrão pertence a uma subclasse de MURAs que apresenta anti-simetria de 90° e conseqüentemente permite a utilização da técnica de subtração de variações sistemáticas de ruído de fundo através de utilização da configuração anti-máscara, obtida com uma simples rotação da máscara. Neste trabalho apresentamos resultados de calibrações em laboratório que tiveram como objetivo testar o sistema imageador. Imagens de fontes radioativas foram obtidas com o telescópio em configuração de vôo, com a máscara girando. Serão discutidos os resultados desses testes e as técnicas desenvolvidas para eliminar ambigüidades de posição de fontes, otimização da relação sinal-ruído e observação de fontes fora do campo totalmente codificado. O sistema de máscara/antimáscara mostrou-se capaz de aumentar a relação sinal-ruído de ~60% para fontes intensas (100 s). Com a máscara girando, a técnica de reconstrução de imagens desenvolvida identificou a posição exata da fonte e não introduziu perda de sensibilidade. Imagens de uma fonte colocada a 8,3° - fora do campo totalmente codificado do telescópio -, mostraram uma diminuição de ~40% na relação sinal/ruído em relação ao centro do campo de visada, o que se deve à codificação incompleta pela máscara e à absorção parcial do fluxo pelos detectores de blindagem.

  17. Modelizacion, control e implementacion de un procesador energetico paralelo para aplicacion en sistemas multisalida

    NASA Astrophysics Data System (ADS)

    Ferreres Sabater, Agustin

    Cualquier sistema electronico que incluya un procesado o tratamiento de la senal, y ademas, algun tipo de actuador mecanico generalmente necesita, como minimo, dos tensiones diferentes de alimentacion. Excluyendo los sistemas de alimentacion distribuida, la solucion tecnica mas utilizada para proporcionar dos o mas tensiones consiste en las fuentes de alimentacion multisalida. En una fuente de alimentacion multisalida los diferentes circuitos que conforman cada salida comparten un mismo transformador de potencia optimizando coste, masa, y volumen. Las ventajas obtenidas con este procedimiento tienen en su contra el efecto que sobre cada salida individual provocan las demas en su conjunto debido, principalmente, a los efectos de los elementos parasitos de los componentes. Un cambio de carga en una de las salidas produce un transitorio que es visto por todas las demas como un efecto de impedancia cruzada, y al final del transitorio, la tension de cada salida es diferente respecto a la que tenian antes del transitorio. Este ultimo resultado se conoce como regulacion cruzada. La disminucion de los efectos de la regulacion cruzada ha sido objeto de estudio durante los ultimos anos. El objetivo ha sido el desarrollo de distintas estrategias que permiten, desde disminuir los efectos de la regulacion cruzada hasta los niveles deseables, a eliminarla completamente. El resultado final suele suponer una penalizacion sobre el diseno del sistema directamente proporcional al grado de regulacion a conseguir en las distintas salidas. Entre las soluciones propuestas para eliminar la regulacion cruzada las tecnicas de post-regulacion se han consolidado como la opcion mas aceptada ya que, pueden aplicarse a cualquier convertidor y no suponen ninguna complejidad adicional a la hora de plantear el diseno. En esta Tesis Doctoral se abordara el estudio de la tecnica conocida como postregulacion mediante transformador controlado, que si bien se ha empleado en convertidores resonantes, su modelizacion, y aplicacion en convertidores PWM, esta aun por estudiar y valorar. El primer Capitulo consiste en una breve introduccion al problema de la regulacion cruzada y la impedancia cruzada para posteriormente describir las tecnicas de post-regulacion actualmente mas empleadas, con especial atencion al post-regulador con transformador controlado. El Capitulo segundo trata del estudio de las caracteristicas estaticas del postregulador con transformador controlado. Partiendo de los estudios disponibles sobre el postregulador se plantean mejoras en su modo de actuacion y se discuten tres alternativas diferentes para controlar el transformador. Las dos primeras consisten en emplear un convertidor auxiliar Boost en sus dos modos de funcionamiento, continuo y discontinuo. La tercera consiste en controlar el transformador con una tension PWM directamente, sin filtrado. Finalmente se comprueba experimentalmente, para el estado estacionario, el funcionamiento del post-regulador para cada uno de los tres metodos de control. El Capitulo tercero trata de la dinamica de la salida controlada con el post-regulador cuando este emplea un convertidor auxiliar tipo Boost. Mediante la tecnica de promediado de variables de estado se propone el modelo de pequena senal, tanto para el modo continuo como para el modo discontinuo de funcionamiento del convertidor auxiliar. Los resultados mas significativos de esta seccion son las expresiones analiticas de las impedancias cruzadas y de la impedancia de la salida post-regulada. Como complemento al modelo de pequena senal se plantea un modelo de gran senal implementado sobre el simulador Pspice. Con este nuevo modelo se reproducen los resultados obtenidos con el modelo de pequena senal y ademas es posible simular los transitorios en las tensiones de salida ante cambios de carga. La modelizacion del convertidor cuando el transformador se controla con una tension PWM sin filtrar es el objetivo del Capitulo 4. En las secciones siguientes del Capitulo se plantea el correspondiente modelo de gran senal aplicado a un nuevo prototipo experimental, de mayor tension de entrada y mayores corrientes de salida. El final del Capitulo contrasta los resultados experimentales con los teoricos confirmando la utilidad del modelo de gran senal como una herramienta basica de diseno. Finalmente, en el Capitulo 5, se presentan las conclusiones y la valoracion de los diferentes estudios plateados a lo largo de la Tesis Doctoral.

  18. Projeto do sistema anti-ressonante da fiação dos transdutores para o detector Mario Schenberg

    NASA Astrophysics Data System (ADS)

    Vieira, S. J.., Jr.; Melo, J. L.

    2003-08-01

    O detector de ondas gravitacionais Mario Schenberg está sendo projetado e construído pelo grupo Gráviton. Sua construção está ocorrendo no Laboratório de Estado Sólido e Baixas Temperaturas (LESBT) da Universidade de São Paulo, na cidade de São Paulo. Esse detector possui uma massa ressonante esférica de cobre-alumínio, com 65 cm de diâmetro, pesando aproximadamente 1150 Kg, suspensa por um sistema de isolamento vibracional, que se encontra em fase de testes preliminares. A real eficácia desse sistema, entretanto, só poderá ser comprovada quando o detector estiver aparelhado com, pelo menos, um transdutor eletromecânico de altíssima sensibilidade acoplado à massa ressonante. Neste momento, não só este sistema de isolamento vibracional será posto em teste, como o do projeto da fiação que transporta os sinais de microondas até os transdutores e destes para a pré-amplificação. Apesar dessa fiação ter sido projetada para não apresentar nenhum contato com a superfície esférica da antena, de maneira a não haver nenhuma transmissão de ruído vibracional do laboratório para esta, deve-se minimizar o ruído microfônico produzido nessa fiação por oscilações mecânicas, uma vez que ela não utiliza nenhum sistema de isolamento vibracional. Com o intuito de resolver este problema, projetamos uma estrutura, formada por pequenos cilindros conectados por barras, a qual não terá nenhuma ressonância mecânica na faixa de freqüências de interesse para detecção (3000 - 3400 Hz). Desta forma, as vibrações nessa faixa não serão amplificadas. O projeto foi feito usando iterativamente, de maneira a otimizar os resultados obtidos, o programa de elementos finitos Msc/Nastran. Através de simulações feitas neste programa, determinamos os parâmetros geométricos ideais a serem utilizados, os quais proporcionam a maior região espectral de interesse livre de ressonâncias.

  19. Transferências orbitais dentro do modelo quase bicircular no sistema Terra-Lua-Sol

    NASA Astrophysics Data System (ADS)

    Corrêa, A. A.; de Almeida Prado, A. F. B.; Stuchi, T. J.; Beaugé, C.

    2003-08-01

    O problema quase bicircular planar consiste na determinação da dinâmica de um corpo, de massa desprezível, que se move sob o campo gravitacional de três corpos. No caso estudado, o quarto corpo é considerado um satélite artificial e os demais são a Terra, a Lua e o Sol, formando o sistema de três corpos. Este modelo permite a construção de uma hamiltoniana similar a do problema restrito de três corpos (PRTC), incluindo termos periódicos não autônomos, provenientes da presença do Sol, portanto pode ser entendido como uma perturbação ao PRTC. Suas órbitas periódicas aparecem isoladas e possuem o mesmo período solar. Os pontos de equilíbrio colineares possuem o mesmo caráter de estabilidade linear dos pontos lagrangianos (L1, L2 e L3) do PRTC, sendo do tipo sela x centro x centro, instável na direção x e estáveis nas direções y e z. As órbitas periódicas tridimensionais ao redor do ponto colinear é chamada órbita Halo. O objetivo deste trabalho é determinar órbitas de transferências de baixo consumo de combustível para um veículo espacial partindo de uma órbita de estacionamento ao redor da Terra em direção a uma órbita Halo do ponto L1, situado entre a Terra e Lua. Esta tarefa pode ser transformada no problema de valor de contorno: dado um ponto inicial na órbita de estacionamento, um ponto final na órbita halo e o tempo de transferência, deseja-se obter a trajetória que liga estes dois pontos e que minimize os incrementos de velocidade do veículo. Essas transferências são realizadas baseadas no método de Lambert e analisadas de modo a fornecer um baixo consumo. Posteriormente, é feita uma comparação de consumo com as órbitas de transferência equivalentes do PRTC.

  20. La distribución de objetos en el Cinturón de Kuiper y la posible existencia de un nuevo planeta en el Sistema Solar

    NASA Astrophysics Data System (ADS)

    Brunini, A.

    A pesar de que la capacidad observacional no lo limita, no se han descubierto objetos en el Cinturón de Kuiper más allá de las 50 AU. Recientemente, hemos propuesto que un embrión planetario originalmente formado en la región de Urano-Neptuno, y posteriormente migrado hacia distancias mayores a 50-60 AU, puede explicar este hecho. Presentamos simulaciones numéricas de acreción del Sistema Solar exterior que muestran cómo, naturalmente, podriamos esperar que un planeta de este tipo se encuentre actualmente en regiones distantes del sistema solar. Analizamos además la posibilidad de detectarlo con instrumentos actuales.

  1. Resonances and Tides in Natural Satellites Systems. (Breton Title: Ressonâncias e Marés em Sistemas de Satélites Naturais.) Resonancias y Mareas en Sistemas de Satélites Naturales

    NASA Astrophysics Data System (ADS)

    Callegari, Nelson, Jr.

    2006-12-01

    In this work we describe some aspects of the dynamics of the mean-motion resonances. Emphasis to the case of resonances between regular satellites of the giant planets will be given, even so some aspects of the physics of the resonances in extra-solar planetary systems are also briefly treated. The role of the resonances in satellites systems is discussed through examples, showing how certain resonances, and its relations with the tidal dissipation effects, can be the key of the explanation of some phenomena still not explained in the Solar System. Amongst some examples we highlight the problem of the resurfacing of Enceladus, the existence of active volcanoes in Io, and the possible existence of the subsurface ocean in Europe. This work has as objective the divulgation of some topics in Celestial Mechanics and Planetary Sciences for an undergraduate public in exact sciences, as Astronomy and Physics, and not their detailed description. Neste trabalho descrevemos alguns aspectos da dinâmica de ressonâncias de movimentos médios. Será dada ênfase maior ao caso de ressonâncias entre satélites regulares dos planetas gigantes, embora alguns aspectos da física das ressonâncias em sistemas planetários extra-solares também sejam discutidos brevemente. A importância do estudo de ressonâncias em sistemas de satélites é discutida mais detalhadamente através de exemplos, mostrando como certas ressonâncias e suas relações com efeitos de dissipação de maré podem ser a chave de parte da explicação de alguns fenômenos ainda não explicados no Sistema Solar. Dentre vários exemplos destacamos o problema da remodelagem da superfície do satélite Enceladus, a existência de vulcões ativos em Io, e a possível existência do oceano subterrâneo em Europa. Este trabalho tem como objetivo a divulgação de alguns tópicos de Mecânica Celeste e Planetologia para um público de nível de graduação em disciplinas na área de exatas, em especial Astronomia e Física, e não a descrição detalhada dos conceitos aqui discutidos. Describimos en este trabajo algunos aspectos de la dinámica de resonancias de movimientos promedio. Será dado un énfasis mayor al caso de las resonancias entre satélites regulares de los planetas gigantes, aunque también son discutidos brevemente algunos aspectos de la física de resonancias en sistemas panetarios extrasolares. La importancia del estudio de las resonancias en sistemas de satélites es discutida más detalladamente através de ejemplos, mostrando cómo ciertas resonancias y los efectos de disipación por mareas pueden ser la clave de parte de la explicación de algunos fenómenos aún no comprendidos en el Sistema Solar. Entre varios ejemplos se destacan el problema de la superficie remodelada del satélite Enceladus, la existencia de volcanes activos en Io y la posible existencia de un océano subterráneo en Europa. Este trabajo tiene como objetivo la divulgación de algunos tópicos en Mecánica Celeste y Planetología para un público universitario de ciencias exactas, en particular Astronomía y Física, y no la descripción detallada de los conceptos aquí discutidos.

  2. The Development of Musical Skills of Underprivileged Children Over the Course of 1 Year: A Study in the Context of an El Sistema-Inspired Program.

    PubMed

    Ilari, Beatriz S; Keller, Patrick; Damasio, Hanna; Habibi, Assal

    2016-01-01

    Developmental research in music has typically centered on the study of single musical skills (e.g., singing, listening) and has been conducted with middle class children who learn music in schools and conservatories. Information on the musical development of children from different social strata, who are enrolled in community-based music programs, remains elusive. This study examined the development of musical skills in underprivileged children who were attending an El Sistema-inspired program in Los Angeles. We investigated how children, predominantly of Latino ethnicity, developed musically with respect to the following musical skills - pitch and rhythmic discrimination, pitch matching, singing a song from memory, and rhythmic entrainment - over the course of 1 year. Results suggested that participation in an El Sistema-inspired program affects children's musical development in distinct ways; with pitch perception and production skills developing faster than rhythmic skills. Furthermore, children from the same ethnic and social background, who did not participate in the El Sistema-inspired music program, showed a decline in singing and pitch discrimination skills over the course of 1 year. Taken together, these results are consistent with the idea of musical development as a complex, spiraling and recursive process that is influenced by several factors including type of musical training. Implications for future research are outlined. PMID:26869964

  3. The Development of Musical Skills of Underprivileged Children Over the Course of 1 Year: A Study in the Context of an El Sistema-Inspired Program

    PubMed Central

    Ilari, Beatriz S.; Keller, Patrick; Damasio, Hanna; Habibi, Assal

    2016-01-01

    Developmental research in music has typically centered on the study of single musical skills (e.g., singing, listening) and has been conducted with middle class children who learn music in schools and conservatories. Information on the musical development of children from different social strata, who are enrolled in community-based music programs, remains elusive. This study examined the development of musical skills in underprivileged children who were attending an El Sistema-inspired program in Los Angeles. We investigated how children, predominantly of Latino ethnicity, developed musically with respect to the following musical skills – pitch and rhythmic discrimination, pitch matching, singing a song from memory, and rhythmic entrainment – over the course of 1 year. Results suggested that participation in an El Sistema-inspired program affects children’s musical development in distinct ways; with pitch perception and production skills developing faster than rhythmic skills. Furthermore, children from the same ethnic and social background, who did not participate in the El Sistema-inspired music program, showed a decline in singing and pitch discrimination skills over the course of 1 year. Taken together, these results are consistent with the idea of musical development as a complex, spiraling and recursive process that is influenced by several factors including type of musical training. Implications for future research are outlined. PMID:26869964

  4. Temporal dynamics of Trichodesmium erythraeum (Cyanophyta) in the National Park "Sistema Arrecifal Veracruzano" in the Gulf of Mexico.

    PubMed

    Aké-Castillo, José A

    2011-07-01

    Trichodesmium erythraeum Ehrenberg ex Gomont is a microalga worldwide distributed in tropical seas. This filamentous microalga was detected in phytoplankton samples collected in the Protected NaturalArea "Parque Nacional SistemaArrecifal Veracruzano", and because of its ecological importance, its temporal dynamics was studied using net samples (30 microm) collected in one year period. Samples were studied with a light microscope recording the presence, morphological characteristics, life form and relative abundance. Trichodesmium erythraeum occurred as single filaments and was rare in April 2007 and March 2008; as single filaments from May to August and December 2007; as single filaments and small aggregates in September 2007 and January 2008; in aggregates of large size (> 3mm) and high relative abundance in October 2007; and was absence in November 2007 and April 2008. Although the relative abundance of the species was not important comparing with other members of phytoplankton, its occurrence was frequent with a bloom at the beginning of the north winds period. The observed temporal dynamics of this microalga in this coral reef region comes up on the alert in the monitoring red tides programs being implemented in Veracruz coast. PMID:22315818

  5. Experiências internacionais da aplicação de sistemas de apoio à decisão clínica em gastroenterologia

    PubMed Central

    Tenório, Josceli Maria; Hummel, Anderson Diniz; Sdepanian, Vera Lucia; Pisa, Ivan Torres; de Fátima Marin, Heimar

    2015-01-01

    Objetivo Descrever as experiências recentes com a aplicação de sistemas de apoio à decisão clínica em gastroenterologia, de forma a estabelecer o nível de desenvolvimento, testes e vantagens conferidas à prática médica com a introdução desses softwares. Métodos Foi realizada busca nas bases de dados PubMed, LILACS e ISI Web of Knowledge, utilizando termos relacionados à sistemas de apoio à decisão e à gastroenterogia, incluindo artigos originais publicados no período entre 2005 e 2010. Foram recuperadas 104 publicações, na busca inicial e, após a aplicação dos critérios de inclusão e exclusão, foram eleitos nove estudos para leitura do texto completo. Resultados Os sistemas de apoio à decisão clínica apresentam grande multiplicidade de problemas clínicos e investigação de doenças. Em 89% dos casos, são descritos modelos experimentais para o desenvolvimento de sistemas de apoio à decisão clínica. A descrição dos resultados obtidos por técnicas de inteligência artificial em 78% das publicações. Em dois dos estudos foram realizadas comparações com o médico e em apenas uma publicação um estudo controlado foi descrito, mostrando evidências de melhorias na prática médica. Conclusão Os estudos mostram potenciais benefícios dos sistemas de apoio à decisão clínica à prática médica, porém, estudos controlados em ambiente real devem ser realizados para comprovar esta perspectiva. PMID:26491625

  6. Principales lignes structurales du Maroc nord-oriental : apport de la gravimétrie

    NASA Astrophysics Data System (ADS)

    Chennouf, Touria; Khattach, Driss; Milhi, Abdellah; Andrieux, Pierre; Keating, Pierre

    2007-05-01

    The present work is based on various filtered maps (horizontal derivative, upward continuation) and Euler deconvolution of the gravity data from northeastern Morocco. These results allow the delineation of many geological structures, such as faults, basins, or diapirs. Some of these structures are hidden totally or partially by the Mesozoic and Cenozoic cover. The results were used to make a structural map of the study area; this map confirms the existence of several faults, localised or inferred, from former geological studies. It complements information on some of them and outlines a great number of deep or near-surface faults that had remained unknown until the present time. The major features show two principal directions: N080°-085° and N055°-065°, with a predominance of the latter, and their depth can reach 4500 m. The N080°-085° directions correspond to the Kebdana, Sidi Bouhouria, Naima, and Guefait faults, and the N055°-065° directions correspond to a fault parallel to the Mediterranean coast and the Moulouya, Madagh, Angad, and Zekkara faults.

  7. ''Principalled'' Leadership in the PDS School: Enhancing the Field Experience for Pre-Service Teachers

    ERIC Educational Resources Information Center

    Klenk, Laura

    2015-01-01

    In the mid-1980s and early 1990s, the Holmes group (1990) laid out a blueprint for leadership in PDS schools, positing that effective principals could foster leadership roles for all participants. Since then other scholars have explored the challenges of establishing strong principal-PDS relationships. This qualitative case study reveals how one…

  8. Le logiciel de simulation, Les données de la grille principale

    NASA Astrophysics Data System (ADS)

    Froeschle, M.; Falin, J. L.; Mignard, F.; Kovalevsky, J.

    The authors describe the processor developed to simulate the data generated by the passage of a star on the main grid of HIPPARCOS. In a first section they present the software required for the preparation of the simulation, namely the attitude motion of the satellite as well as its relative displacement with respect to the barycenter of the solar system. In particular, allowance is made in the authors' routine for the interruptions of observations because of the presence of the earth or the moon in an extended FOV. Then the main lines of the observation strategy are described.

  9. How to Keep Your Campus Safe from Infection

    ERIC Educational Resources Information Center

    Brown, Scott

    2005-01-01

    In this article, the author explains how antivirus programs work. He also explains how performances of various antivirus programs vary from one to another. He also takes a look at 13 antivirus programs and explains which of these will keep computers protected. These programs include: (1) Sophos Anti-Virus Version 3.86.2; (2) McAfee VirusScan 9.0;…

  10. How to Keep Your Campus Safe from Infection

    ERIC Educational Resources Information Center

    Brown, Scott

    2005-01-01

    In this article, the author explains how antivirus programs work. He also explains how performances of various antivirus programs vary from one to another. He also takes a look at 13 antivirus programs and explains which of these will keep computers protected. These programs include: (1) Sophos Anti-Virus Version 3.86.2; (2) McAfee VirusScan 9.0;…

  11. A critical view of the 'social reinsertion' concept and its implications for the practice of psychologists in the area of mental health in the Brazilian Unified Health System (Sistema Único de Saúde).

    PubMed

    Frazatto, Carina F; Sawaia, Bader B

    2016-03-01

    Improving psychological practice in mental health services in the Brazilian Unified Health System (Sistema Único de Saúde) requires a critical analysis of core concepts of the psychiatric reform, such as 'social reinsertion'. This analysis, oriented by the dialectics of exclusion/inclusion, showed that this concept is impregnated with the adaptation paradigm and asylum view which prevents its effective implantation. The results suggest it is necessary to include social aspects in the discussion of mental health, articulating it with networks of social work and recuperating the revolutionary aspects of the psychiatric reform, thus demarcating the political nature of professional practices. PMID:26987835

  12. The Forum for Defence of the Brazilian Unified Health System (Sistema Único de Saúde) and its role in building community participation in the fight against the privatization of health.

    PubMed

    de Lara, Lutiane; de Fátima Guareschi, Neuza Maria

    2016-03-01

    Based on a Foucauldian framework, this article discusses the involvement of the Forum for Defence of the Sistema Único de Saúde in the fight against health care privatization. Community participation is a locus of experience that produces subjects implicated in the production of public health care. The locus of experience in this instance derives from the rejection of private elements that historically have been part of Brazilian public policies. It is an experience that produces workers and service users as agents able to defend the public system and endowed with instituting power. PMID:26987838

  13. Correlação de longo alcance em sistemas binários de raios-x usando remoção de flutuações

    NASA Astrophysics Data System (ADS)

    Pereira, M. G.; Moret, M. A.; Zebende, G. F.; Nogueira, E., Jr.

    2003-08-01

    Neste trabalho é proposta uma metodologia de analise de series temporais de fontes astrofísicas, baseada no método proposto por Peng et al. (1994) e Liu et al. (1999), o qual consiste na idéia de que uma série temporal correlacionada pode ser mapeada por um processo de busca de auto-similaridades em diversas escalas de tempo n. Removendo as eventuais tendências e integrando o sinal observado, é obtida uma medida do desvio médio quadrático das flutuações do sinal integrado F(n)~na, onde a representa o fator de escala associado com a auto-similaridade da correlação de longo alcance do sinal. Baseado nos valores obtidos de a, é possível distinguir entre os casos de sinais não-correlacionados, tipo ruído branco (a = 0,5), sinal anti-persistentes (a < 0,5) e sinal persistente (a > 0,5). Usando esta metodologia, foram analisadas 129 curvas de luz de sistemas binários de raios-X, provenientes do banco de dados públicos de observações feitas pelo instrumento All Sky Monitor, a bordo do satélite Rossi X-Ray Timing Explorer (ASM-RXTE). Foram identificadas a presença de a'0,5 em mais de 90% dos sistemas estudados, implicando em dizer que as flutuações de intensidade observadas apresentam correlação de auto-similaridade, sem entretanto, indícios de apresentarem uma escala de tempo característica das flutuações de intensidade. Sistemas onde são observadas erupções (flares), apresentam sistematicamente a > 0,5, característica esta, possivelmente associada com persistência das flutuações de densidade de disco ou taxa de acréscimo de massa. Os sistemas com curvas de luz onde nao são observadas as erupções apresentam uma distribuição normal centrada em a~0,62+/-0,10. Referências ¾ Peng, C.-K., Buldyrev, S.V., Havlin, S., Simons, M., Stanley, H.E., e Goldberg, A.L., Phys. Rev. E, (49), 1685 (1994). ¾ Liu, Y., Gopikrishnan, P., Cizeau, P., Meyer, M., Peng,C.-K., e Stanley, H.E., Phys. Rev. E, (60), 1390 (1999).

  14. Aspergilosis cervical con diseminación al sistema nervioso central. Presentación de un caso y revisión de bibliografía

    PubMed Central

    Vergara, Guillermo Enrique; Roura, Natalia; del Castillo, Marcelo; Mora, Andrea; Alcorta, Santiago Condomi; Mormandi, Rubén; Cervio, Andrés; Salvat, Jorge

    2015-01-01

    Introducción: la Aspergilosis Invasiva (AI) del Sistema Nervioso Central (SNC) es infrecuente y ocurre generalmente en pacientes inmunocomprometidos. Puede presentarse con cuadros de meningitis, aneurismas micóticos, infartos o abscesos. Es una infección con pronóstico reservado y puede afectar el SNC de forma primaria o secundaria a partir de un foco que se disemina por vía hematógena. Presentamos el caso de un paciente con AI con invasión primaria a nivel óseo y diseminación posterior al cerebro. Caso clínico: Paciente masculino de 25 años con diagnóstico de leucemia linfática aguda en tratamiento quimioterápico que presentó neumonitis por metotrexate por lo que inicia tratamiento con corticoides. Posteriormente agregó cervicalgia y con el diagnóstico de osteomielitis cervical se realiza punción bajo tomografía computada (TC) sin aislarse gérmenes. Se colocó Halo Vest e inició tratamiento antibiótico empírico. Posteriormente presentó afasia de expresión secundaria a lesión frontal izquierda. Se realizó evacuación de absceso cerebral aislando A. fumigatus. El tratamiento antibiótico específico posterior permitió una buena respuesta clínica y radiológica. Conclusión: La presencia de lesiones en el SNC de pacientes inmunocomprometidos debe incluir a las micosis como diagnóstico diferencial. La evacuación quirúrgica permite llegar rápidamente al diagnóstico mejorando la respuesta posterior al tratamiento antibiótico. Para evaluar la respuesta terapéutica y posibles recaídas se debe realizar un seguimiento periódico clínico radiológico. Palabras clave: Aspergilosis cerebral; Aspergilosis cervical; Aspergilosis invasiva; Voriconazol. PMID:26600985

  15. Analisis del contenido curricular de los Documentos Normativos del Programa de Ciencias en el area de biologia para la escuela superior del sistema de educacion publica de Puerto Rico: 1993-2012

    NASA Astrophysics Data System (ADS)

    Davila Montanez, Melissa

    Esta investigacion de naturaleza cualitativa se ocupo de realizar un analisis de contenido documental de los Documentos Normativos del Programa de Ciencias en el area de biologia de la escuela superior del sistema de educacion publica de Puerto Rico del periodo 1993-2012. Los documentos analizados fueron: Guia Curricular, 1995; Marco Curricular, 2003; Estandares de Excelencia, 1996, 2000 y Estandares de Contenido y Expectativas de Grado, 2007. Se indago si hubo cambios en significados en los Componentes Estructurales: Naturaleza de la ciencia, Paradigmas para la ensenanza de la ciencia, Funcion del curriculo formal, Mision de la ensenanza de la ciencia; Contenidos, destrezas y competencias, Estrategias de ensenanza y Evaluacion/Assessment del aprendizaje. El analisis sugiere que no hubo cambios sustanciales en los significados de los Componentes Estructurales. Los documentos estudiados muestran mayormente caracteristicas similares, aunque los documentos mas recientes eran mas descriptivos, explicativos y especificos.

  16. NASA Astrophysics Data System (ADS)

    Brunini, A.

    Se presenta una revisión de los conocimientos actuales sobre el proceso de acreción del sistema solar exterior. En base a nuevas y más realistas simulaciones numéricas, se analiza el impacto que tuvo dicho proceso en otras regiones del sistema solar tales como la nube de Oort, el cinturón de Kuiper y el sistema solar interior. Se presentan entonces, las principales limitaciones de los modelos numéricos actuales, los principales puntos aún oscuros en el problema, y algunos de los posibles caminos a seguir para mejorar nuestro conocimiento en el tema. Se discute a continuación la posible utilidad de este tipo de estudios para el diseño de estrategias de búsqueda de otros sistemas planetarios.

  17. ASI-Sistema Rischio Vulcanico SRV: a pilot project to develop EO data processing modules and products for volcanic activity monitoring based on Italian Civil Protection Department requirements and needs

    NASA Astrophysics Data System (ADS)

    Buongiorno, Maria Fabrizia; Musacchio, Massimo; Silvestri, Malvina; Spinetti, Claudia; Corradini, Stefano; Lombardo, Valerio; Merucci, Luca; Sansosti, Eugenio; Pugnagli, Sergio; Teggi, Sergio; Pace, Gaetano; Fermi, Marco; Zoffoli, Simona

    2007-10-01

    The Project called Sistema Rischio Vulcanico (SRV) is funded by the Italian Space Agency (ASI) in the frame of the National Space Plan 2003-2005 under the Earth Observations section for natural risks management. The SRV Project is coordinated by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) which is responsible at national level for the volcanic monitoring. The objective of the project is to develop a pre-operative system based on EO data and ground measurements integration to support the volcanic risk monitoring of the Italian Civil Protection Department which requirements and need are well integrated in the GMES Emergency Core Services program. The project philosophy is to implement, by incremental versions, specific modules which allow to process, store and visualize through Web GIS tools EO derived parameters considering three activity phases: 1) knowledge and prevention; 2) crisis; 3) post crisis. In order to combine effectively the EO data and the ground networks measurements the system will implement a multi-parametric analysis tool, which represents and unique tool to analyze contemporaneously a large data set of data in "near real time". The SRV project will be tested his operational capabilities on three Italian Volcanoes: Etna,Vesuvio and Campi Flegrei.

  18. Architecture for removable media USB-ARM

    DOEpatents

    Shue, Craig A.; Lamb, Logan M.; Paul, Nathanael R.

    2015-07-14

    A storage device is coupled to a computing system comprising an operating system and application software. Access to the storage device is blocked by a kernel filter driver, except exclusive access is granted to a first anti-virus engine. The first anti-virus engine is directed to scan the storage device for malicious software and report results. Exclusive access may be granted to one or more other anti-virus engines and they may be directed to scan the storage device and report results. Approval of all or a portion of the information on the storage device is based on the results from the first anti-virus engine and the other anti-virus engines. The storage device is presented to the operating system and access is granted to the approved information. The operating system may be a Microsoft Windows operating system. The kernel filter driver and usage of anti-virus engines may be configurable by a user.

  19. 48 CFR 352.239-70 - Standard for security configurations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... operating system patch level and anti-virus software level. Note: FDCC is applicable to all computing... privileges. (e) The Contractor shall ensure hardware and software installation, operation,...

  20. Sistemas Planetarios en Presencia de Júpiters Calientes

    NASA Astrophysics Data System (ADS)

    de Elía, G. C.; Guilera, O. M.; Brunini, A.

    In the present work we show results of N-body simulations aimed at analyzing the main dynamical aspects concerning the evolution of planetary embryos during the formation and evolution of a Hot Jupiter, for different values of the giant planet mass and the migration timescale. FULL TEXT IN SPANISH

  1. Interacciones de galaxias: sistemas con puentes tidales

    NASA Astrophysics Data System (ADS)

    Mesa, V.; Alonso, S.; Duplancic, F.; Lambas, D. G.

    2015-08-01

    In this work we present a sample of interacting galaxy pairs connected by a bridge, obtained from a visual classification of a pair catalogue derived from the seventh data release of the Sloan Digital Sky Survey (SDSS-DR7). We present preliminary results of the general characteristics of galaxies in these systems, such as specific star formation rate, age of the stellar populations, concentration index, colour and local density environment.

  2. A Descriptive Case Study of a School-Wide Positive Behavior Support (PBS) System in Schools with Principal-Led Planning Teams and Coach-Led Planning Teams

    ERIC Educational Resources Information Center

    McWilliams, Ellen K.

    2011-01-01

    Managing disruptive behaviors in schools is a high-ranking concern in communities across the country (Rose & Gallup, 2006). Unfortunately, the practice of instituting tougher and more severe consequences for increased discipline problems has not resulted in a decrease of disruptive behavior (Lewis & Garrison-Harrell, 1999; Safran & Oswald, 2003;…

  3. A Descriptive Case Study of a School-Wide Positive Behavior Support (PBS) System in Schools with Principal-Led Planning Teams and Coach-Led Planning Teams

    ERIC Educational Resources Information Center

    McWilliams, Ellen K.

    2011-01-01

    Managing disruptive behaviors in schools is a high-ranking concern in communities across the country (Rose & Gallup, 2006). Unfortunately, the practice of instituting tougher and more severe consequences for increased discipline problems has not resulted in a decrease of disruptive behavior (Lewis & Garrison-Harrell, 1999; Safran & Oswald, 2003;…

  4. Drive-by-Downloads

    SciTech Connect

    Narvaez, Julia; Endicott-Popovsky, Barbara E.; Seifert, Christian; Aval, Chiraag U.; Frincke, Deborah A.

    2010-02-01

    Abstract: Drive-by-downloads are malware that push, and then execute, malicious code on a client system without the user's consent. The purpose of this paper is to introduce a discussion of the usefulness of antivirus software for detecting the installation of such malware, providing groundwork for future studies. Client honeypots collected drive-by malware which was then evaluated using common antivirus products. Initial analysis showed that most of such antivirus products identified less than 70% of these highly polymorphic malware programs. Also, it was observed that the antivirus products tested, even when successfully detecting this malware, often failed to classify it, leading to the conclusion that further work could involve not only developing new behavioral detection technologies, but also empirical studies that improve general understanding of these threats. Toward that end, one example of malicious code was analyzed behaviorally to provide insight into next steps for the future direction of this research.

  5. 78 FR 9386 - Procurement List; Proposed Additions and Deletions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-08

    ...-9694--USB 2.0 Hard Drive, Portable, 320G NSN: 7045-01-599-9345--USB Flash Drive, 256-Bit AES Encryption, Level 3 Encrypted, Anti-Virus, 4GB NSN: 7045-01-599-9346--USB Flash Drive, 256-Bit AES Encryption, Level 3 Encrypted, Anti-Virus, 32GB NSN: 7045-01-599-9348--USB Flash Drive, 256-Bit AES Encryption,...

  6. El enfoque de sistemas en programas de seguridad cuarentenaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a globalized world, the application of phytosanitary measures for quarantine by the producing countries is becoming more important as it facilitates access to key export markets for fruits and vegetables. Some of the problems currently encountered with quarantine treatments include, among others...

  7. Diversidad de Sistemas Planetarios en Discos de Baja Masa

    NASA Astrophysics Data System (ADS)

    Ronco, M. P.; de Elía, G. C.

    The accretion process that allows the formation of terrestrial planets is strongly dependent on the mass distribution in the system and the presence of gas giant planets. Several studies suggest that planetary systems formed only by terrestrial planets are the most common in the Universe. In this work we study the diversity of planetary systems that could form around solar-type stars in low mass disks in absence of gas giants planets and search wich ones are targets of particular interest. FULL TEXT IN SPANISH

  8. The Mexican Sistema de Alerta Sismica (SAS) Experience

    NASA Astrophysics Data System (ADS)

    Espinosa-Aranda, J.; Rodriguez, F.

    2003-12-01

    The Mexico City's SAS is an Early Warning System developed in accordance with recommendations of foreign and national seismology experts, after the disaster generated in 1985 by the M8.1 Michoacan earthquake. The SAS aim is to help mitigate future seismic disasters in Mexico City (MC), mainly if the big forecast "Guerrero Earthquake" hits. In 1991 the SAS started its service in an experimental basis for evaluating its performance both with a group of basic education students in public schools, and with the emergency stop function for the Mexico City Metropolitan Subway System (METRO of MC); after this The Federal District Government (FDG) opened the SAS as a public service in August, 1993, shortly after the SAS warned, with more than 60 seconds of anticipation, the incoming effect of May 13, 1993, M5.8, and M6 double earthquake originated more than 300 Km from MC between Guerrero and Oaxaca, on the coast. That year, an initial technical flaw generated one false alert signal; the cause was readily corrected. The SAS has 12 seismic sensor stations covering a stripe close to 400 X 100 Km on the Guerrero's coast, between Papanoa and Punta Maldonado, that send information through a dedicated radio relay system to the SAS Central Control in MC., using the valuable support of some TELMEX field installations. Until August, 2003, the SAS sensor system has detected more than 1550 earthquakes in the 2.55 magnitude events, which are the ones felt in MC. The SAS has generated 57 warning signals with an average of 60 sec in advance to earthquake effects: 46 of restricted use for M<6, and 11 of public use for M>6 events. Public warnings have the automatic broadcast support of many commercial radio AM/FM and TV stations in Mexico City and Toluca valleys. The FDG controls the SAS signal service that includes the more frequent events (from M>5 up), asking the user to develop procedures and practice useful actions to mitigate seismic disasters. Each validated SAS seismic warning automatically generates and sends the event information by fax and e-mail to the DFG and Civil Protection Authorities, users and news media; it also sends information about the SAS operating conditions to service technicians, via radio, and phone.

  9. Momentos centrados en sistemas estelares a simetria axial.

    NASA Astrophysics Data System (ADS)

    Sanz Subirana, J.; Juan Zornoza, J. M.; Català Poch, M. A.

    Centered moments in the galactic plane have been analytically determined up to the fourth order for a non-stationary stellar system model with a distribution of peculiar velocities of the stars symmetric under point-axial transformations and equatorial plane reflexions. The obtained results explain satisfactorily the peculiar velocities distribution of the considered stellar samples in the solar neighborhood.

  10. EL Sistema CCD de Tonantzintla. Pruebas Y Planes Futuros

    NASA Astrophysics Data System (ADS)

    Cardona, O.; Chavira, E.; Furenlid, L.; Iriarte, B.

    1987-05-01

    We present results of the laboratory tests of the CCD camera system recently acquired by INAOE, also the theoretical and observational performance of the instrument with the one meter telescope of UNAM. The system has a TI 4849 CCD with 390 >c 584 pixels. We will present the future plans of its use in the new 2.1 m telescope at Cananea, onora.

  11. Universal Serial Bus Architecture for Removable Media (USB-ARM)

    SciTech Connect

    2011-03-09

    USB-ARM creates operating system drivers which sit between removable media and the user and applications. The drivers isolate the media and submit the contents of the media to a virtual machine containing an entire scanning system. This scanning system may include traditional anti-virus, but also allows more detailed analysis of files, including dynamic run-time analysis, helping to prevent “zero-day” threats not already identified in anti-virus signatures. Once cleared, the media is presented to the operating system, at which point it becomes available to users and applications.

  12. Universal Serial Bus Architecture for Removable Media (USB-ARM)

    Energy Science and Technology Software Center (ESTSC)

    2011-03-09

    USB-ARM creates operating system drivers which sit between removable media and the user and applications. The drivers isolate the media and submit the contents of the media to a virtual machine containing an entire scanning system. This scanning system may include traditional anti-virus, but also allows more detailed analysis of files, including dynamic run-time analysis, helping to prevent “zero-day” threats not already identified in anti-virus signatures. Once cleared, the media is presented to the operatingmore » system, at which point it becomes available to users and applications.« less

  13. Virus Alert: Ten Steps to Safe Computing.

    ERIC Educational Resources Information Center

    Gunter, Glenda A.

    1997-01-01

    Discusses computer viruses and explains how to detect them; discusses virus protection and the need to update antivirus software; and offers 10 safe computing tips, including scanning floppy disks and commercial software, how to safely download files from the Internet, avoiding pirated software copies, and backing up files. (LRW)

  14. Safe Computing: An Overview of Viruses.

    ERIC Educational Resources Information Center

    Wodarz, Nan

    2001-01-01

    A computer virus is a program that replicates itself, in conjunction with an additional program that can harm a computer system. Common viruses include boot-sector, macro, companion, overwriting, and multipartite. Viruses can be fast, slow, stealthy, and polymorphic. Anti-virus products are described. (MLH)

  15. The Computer Virus Threat and What You Can Do about It.

    ERIC Educational Resources Information Center

    Lateulere, John

    1992-01-01

    Discussion of computer viruses describes two types of viruses and how they work; suggests ways to prevent or minimize virus risk; and explains how to recognize a virus and limit damage once a virus attacks. A sidebar lists several antivirus software products. (two references) (NRP)

  16. Computer Viruses: Pathology and Detection.

    ERIC Educational Resources Information Center

    Maxwell, John R.; Lamon, William E.

    1992-01-01

    Explains how computer viruses were originally created, how a computer can become infected by a virus, how viruses operate, symptoms that indicate a computer is infected, how to detect and remove viruses, and how to prevent a reinfection. A sidebar lists eight antivirus resources. (four references) (LRW)

  17. How Much Security Does Your Library Need?

    ERIC Educational Resources Information Center

    Banerjee, Kyle

    2003-01-01

    Explains how to keep library systems healthy and functioning by taking sensible security measures. Examines why hackers would target library systems and how library systems are compromised. Describes tools that can help, including: firewalls; antivirus software; alarms; network analysis tools; and encryption. Identifies several strategies for…

  18. Variant Rabbit Hemorrhagic Disease Virus in Young Rabbits, Spain

    PubMed Central

    Dalton, Kevin P.; Nicieza, Inés; Balseiro, Ana; Muguerza, María A.; Rosell, Joan M.; Casais, Rosa; Álvarez, Ángel L.

    2012-01-01

    Outbreaks of rabbit hemorrhagic disease have occurred recently in young rabbits on farms on the Iberian Peninsula where rabbits were previously vaccinated. Investigation identified a rabbit hemorrhagic disease virus variant genetically related to apathogenic rabbit caliciviruses. Improved antivirus strategies are needed to slow the spread of this pathogen. PMID:23171812

  19. How To: Protect against a Zero-Hour Attack

    ERIC Educational Resources Information Center

    McCarthy, Rob

    2005-01-01

    In the last year, a series of viruses and worms that caused damage across the Internet in record time has made very clear how vulnerable computer systems are. The MS Blaster, Slammer, Sasser, and Korgo.W worms have shown that signature-based antivirus software and traditional firewalls are not enough to protect networks. Everyone is worried about…

  20. Lock It Up! Computer Security.

    ERIC Educational Resources Information Center

    Wodarz, Nan

    1997-01-01

    The data contained on desktop computer systems and networks pose security issues for virtually every district. Sensitive information can be protected by educating users, altering the physical layout, using password protection, designating access levels, backing up data, reformatting floppy disks, using antivirus software, and installing encryption…

  1. Peace (of Mind) in Our Time

    ERIC Educational Resources Information Center

    Panettieri, Joseph C.

    2007-01-01

    There's no silver bullet to information security; universities must continue to keep their antivirus, anti-spyware, firewall, and patch management systems in good working order. These days, the largest target for hackers appears to be university databases. Now, universities are searching for new solutions to safeguard those systems. This article…

  2. How Much Security Does Your Library Need?

    ERIC Educational Resources Information Center

    Banerjee, Kyle

    2003-01-01

    Explains how to keep library systems healthy and functioning by taking sensible security measures. Examines why hackers would target library systems and how library systems are compromised. Describes tools that can help, including: firewalls; antivirus software; alarms; network analysis tools; and encryption. Identifies several strategies for…

  3. Science and Technology Resources on the Internet: Computer Security.

    ERIC Educational Resources Information Center

    Kinkus, Jane F.

    2002-01-01

    Discusses issues related to computer security, including confidentiality, integrity, and authentication or availability; and presents a selected list of Web sites that cover the basic issues of computer security under subject headings that include ethics, privacy, kids, antivirus, policies, cryptography, operating system security, and biometrics.…

  4. Peace (of Mind) in Our Time

    ERIC Educational Resources Information Center

    Panettieri, Joseph C.

    2007-01-01

    There's no silver bullet to information security; universities must continue to keep their antivirus, anti-spyware, firewall, and patch management systems in good working order. These days, the largest target for hackers appears to be university databases. Now, universities are searching for new solutions to safeguard those systems. This article…

  5. How To: Protect against a Zero-Hour Attack

    ERIC Educational Resources Information Center

    McCarthy, Rob

    2005-01-01

    In the last year, a series of viruses and worms that caused damage across the Internet in record time has made very clear how vulnerable computer systems are. The MS Blaster, Slammer, Sasser, and Korgo.W worms have shown that signature-based antivirus software and traditional firewalls are not enough to protect networks. Everyone is worried about…

  6. Una guia a los padres acerca del sistema educacional = A Parent's Guide to Education. Spanish Edition.

    ERIC Educational Resources Information Center

    Rowch, Nancy

    A guide for Spanish-speaking parents of elementary and secondary school students in Nebraska provides in Spanish, and then in English, information concerning education in the state. Topics covered include: state policy concerning enrolling children in school, medical requirements for enrollment and attendance, the school curriculum requirements…

  7. Curso Introductorio sobre el Sistema DIALOG (Introductory Course on the DIALOG System).

    ERIC Educational Resources Information Center

    Rodriguez, Ketty

    As an introduction to the use of the DIALOG online retrieval service, this guide presents material that was developed during a fellowship at Carlos III University, School of Library Science and Documentation, Madrid (Spain) and that is based on a course on the same subject taught in English at Texas Women's University. Although the use of DIALOG…

  8. Crecimiento adiabático de un agujero negro en el centro de un sistema estelar

    NASA Astrophysics Data System (ADS)

    Arrigoni, M.; Carpintero, D. D.

    We present preliminary results on the dynamical influence of an adiabatically grown central black hole upon its surroundings. Young (1980), in his pioneer work, found an r-3/2 density profile for the neighborhood of a black hole, a result not confirmed by observation. In this work, we extend Young's result to a more realistic case, namely an inhomogeneous galactic center, although keeping the spherical symmetry hypothesis, in order to verify whether the final density profile changes.

  9. Interacciones de galaxias: sistemas co-rotantes y contra-rotantes

    NASA Astrophysics Data System (ADS)

    Mesa, V.; Duplancic, F.; Alonso, S.; García Lambas, D.

    In this paper we present a sample of interacting galaxy pairs with tidal tails. We perform a visual cassification according to the sense of rotation of the spiral arms of each member of the tidal system. We study general features of interacting galaxies such as mass content in stars (M^*), luminosity ratios and local environment through an analysis of the Σ_5 parameter. FULL TEXT IN SPANISH

  10. Supernovas y ``Viudas Negras``: Evolución en sistemas binarios

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.

    In this article; on the occasion of receiving the José Luis Sérsic award of our Association; I present a brief discussion of the topics I am currently working on; related to the evolution of stellar close binary systems with exchange of mass. In particular; I present an abridged discussion of the work we have done in order to account for the observed properties of supernova SN 2011dh and the evolution of low mass systems that lead to the formation the so called ``black widow'' systems. Also; I consider timely to publicly acknowledge to those who helped and accompanied me in the adventure of scientific research. FULL TEXT IN SPANISH

  11. Investigacion Participativa y Gestion de Sistemas Educativos. (Participatory Research and the Management of Educational Systems).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    Elements which, when put in harmony, might generate powerful tools for social change and educational development are (1) the ever present need of the educational systems to evaluate their performance; (2) the universal acceptance of the life-long education concept as a major guideline to design educational programs; (3) the trend toward a…

  12. Estudio de la Velocidad de Rotacion EN LOS Sistemas Estelares a Simetria Axial

    NASA Astrophysics Data System (ADS)

    Sanz, J.; Catala, M. A.

    1986-12-01

    This paper contains the calculation of the tangential component of the velocity for a model of galaxy with axial symmetry, non.stationary state and equatorial symmetry plane, from the postulates and fundamental equations of Chandrasekhar theory, that shows a shift of the maximum for different values of the Z coordinate and the 0 direction. Key words: STELLAR DYNAMICS - STELLAR SYSTEMS

  13. Sistemas exoplanetarios múltiples: estadísticas y clasificación

    NASA Astrophysics Data System (ADS)

    Hobson, M. J.; Gómez, M.

    2015-08-01

    459 multiplanet systems are currently known, of which 50 possess four or more planets. We present statistical analyses of the physical properties of both the host stars and the planets, and of the orbital configurations of these systems. We devote special attention to the 50 most populated systems, performing a metallicity analysis of the host stars, and a measure of the compactness of each system. We investigate if the planets are ordered preferentially by size in their systems. We analyse the diversity of the known multiplanet systems with relation to the Solar System.

  14. Sistemas Eolicos Pequenos para Generacion de Electricidad: Una guia para consumidores en Nuevo Mexico

    SciTech Connect

    Not Available

    2007-09-01

    This Spanish version of the popular Small Wind Electric Systems: A New Mexico Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  15. Sistemas Eolicos Pequenos para Generacion de Electricidad; Una guia para consumidores en los EE.UU.

    SciTech Connect

    Not Available

    2007-09-01

    This Spanish version of the popular Small Wind Electric Systems: A U.S. Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  16. Sintesis y caracterizacion de portadores magneticos coloidales. Aplicaciones al diseno de sistemas de liberacion de farmacos

    NASA Astrophysics Data System (ADS)

    Gomez Lopera, Salvador Angel

    2003-10-01

    The present work is mainly dedicated to the synthesis and characterization of composite colloidal particles with a magnetic core (magnetite) and a polymeric biodegradable material shell (poly(DL-lactide), PLA). The aim is to use them as drug carrier systems in the field of controlled (or modified) release. The appropriate synthesis conditions are analyzed for such purpose, starting with the synthesis of the magnetic nuclei, and continuing with that of microspheres of the polymer used later as shell material. The final step is the manufacture of the composite colloids. In order to have a good comparison, all the experiments of the work have been run in triplicate, that is, for the three individual materials (magnetic nuclei, PLA and composite particles magnetite/PLA) and all the discussions are presented by way of parallel study of the three colloidal systems. The following surface and bulk properties have been studied: shape and size of the particles, specific surface area, chemical composition. The magnetic behavior of the nuclei is characterized, as well as that of the composite particles, through measurement of the magnetic susceptibility and the hysteresis cycles. In addition, a study of the electrokinetic behavior of the systems as a function of pH---at constant ionic strength---has been complemented by an investigation of their surface thermodynamics to check the extent of coverage achieved. Very significant results were also obtained in the analysis of the stability of the suspensions. Since our final aim was the design of a drug carrier and controlled release system, we also present a series of preliminary results concerning the effect of the glucocorticoid betamethasone 21-phosphate sodium salt on the surface electrical properties of the three kinds of particles, observing clear differences between the behavior of magnetite particles and of composite or pure polymeric colloids. It is demonstrated that the polymer layer affects considerably the capacity of the colloid for adsorbing this drug and, probably, other drugs of interest in the treatment of those pathologies in which one needs an elevated local concentration of any therapeutic product but without adverse side effects, like those used in the chemotherapy of the solid tumors.

  17. Evolución de estrellas que pertenecen a sistemas binarios cerrados

    NASA Astrophysics Data System (ADS)

    De Vito, M. A.; Benvenuto, O. G.

    Stellar evolution in close binary systems (CBSs, those in which one or more mass transfer/mass loss episodes can occur) is a topic of great interest in Astronomy. The reason is that a large fraction of the stars belong to CBSs and this has originated our interest for the study of such systems. Based on the stellar evolution code for isolated stars developed in the Facultad de Ciencias Astronómicas y Geofísicas (UNLP) by Dr. O.G. Benvenuto, we have built a new code that can compute the evolution of stars members of CBSs. The version of the code we have employed in performing the calculations we show in this work, make a great advance in the study of this kind of systems, since the rate of mass loss is computed in an self-consistent fashion. For this purpose, we have incorporated in the code for isolated stars a new variable in the iterations: the rate of mass loss dot{M}. In addition, we need to compute a critical radius that discern if the star is lossing mass or not. Based on the experience of other authors we have defined the radius of the Roche lobe as a critical radius in such a way that if the stellar radius overflows this, mass loss will occur. On the other hand, if the stellar radius is smaller, the evolution proceeds as if the star were isolated. If all mass lost from a star is deposited on the surface of its companion, and total systemic energy is conserved we have a conservative case. However, we have included in our code effects of energy loss for ejection of matter from the system, and consider dissipative effects like gravitational radiation and magnetic braking. This considerations causes different results from conservative case. Inasmuch as, in view of the non conservation of total angular momentum, it is necessary to perform a careful calculation of the orbital evolution. We present the evolution of four primary stars (the initially more massive star in the systems) with the following characteristics: - Initial masses of 1.5 and 2 M⊙, initial period of 0.7 days, and initial mass ratio of 1.5. Case A (mass transfer begin during core hydrogen burning), non conservative. - Initial masses of 2 and 1.4 M⊙, initials periods of 1.5 and 1 days, initial mass ratios of 1.5 and 1, respectively. Case B (mass transfer begin during central contraction after central hydrogen exhaustion), non conservative. We have also shown the results obtained with a version of the code, in preparation, that performs the evolution for both stars belonging to a CBS simultaneously. It is a CBS in which the initial mass of the primary is 10 M⊙, the initial period of 6 days and the initial mass ratio of 1.25. Case B, conservative.

  18. Coexistencia e integracion de comunicaciones inalambricas en sistemas de transmision opticos

    NASA Astrophysics Data System (ADS)

    Perez Soler, Joaquin

    Current network and telecommunication systems are required to provide higher data rates in access networks to an increasing number of users. This fact is mainly due to the increase in the Internet traffic data, which is related with the higher demand of online videogames and software, the increased complexity in the content of web pages, the joint distribution of audio-visual and added-value online content, and the introduction of high-definition services and contents such as video on demand, as a result of a society increasingly more interconnected. In order to satisfy these higher data rates requirements, new techniques for the joint distribution of several wireless communication systems are proposed in this Thesis. The aim of these techniques is to facilitate the deployment of an integrated access network at the customer premises, enabling the integration of optical transmission over an optical access network and radio-frequency transmission in the same infrastructure. Two main wireless communication systems are considered in this Thesis, WiMAX (Worldwide Interoperability for Microwave Access) and UWB (Ultra-Wide Band) according to WiMedia Alliance recommendation. Comparing the bit rate and expected range, WiMAX and UWB are complementary radio technologies expected to coexist in a near future in integrated access networks. The optical access network considered in this Thesis can be regarded as a FTTH network (Fibre-to-the-Home). The wireless signals are natively transmitted over optical network, that is, without frequency upconversion and remodulation stages, over one or several optical carriers. This technology, which is known as Radio-over-Fibre (RoF), is well suited for integrated access networks. First, the requirements for the wireless convergence of services based on Multi-Band Orthogonal-Frequency Division-Multiplexing UWB (MB-OFDM UWB) and WiMAX 802.16e in Wireless Personal Area Networks (WPAN) are stated. The aim of this study is to provide relevant protection margins in order to ensure the coexistence between both technologies. The obtained protection margins are of great interest for the development of advanced interference mitigation techniques such as DAA (Detect-and-Avoid), in the framework of future cognitive radio technologies. In a second step, the wireless coexistence of MB-OFDM UWB and WiMAX technologies is analyzed from the point of view of access networks based on RoF systems. Two experimental field trials are here carried out. In the first one, the wireless convergence is evaluated in a multi-mode fibre RoF system, whereas in the second one, the RoF system is based on a standard single-mode fibre. These experimental results provide relevant fibre link transmission distances to enable the deployment of RoF networks. Moreover, a new optical transmission technique based on polarization division multiplexing is proposed and experimentally evaluated in order to ensure the wireless coexistence in RoF systems. Finally, the impact of the electro-optical Mach-Zehnder modulator is analyzed, since the dynamic range of this device limits the performance of the RoF system. Moreover, a new optical linearization technique for Mach-Zehnder modulators is proposed and evaluated in order to overcome this limitation.

  19. Sistemas binarios viuda negra: conectando sus orígenes con su estado final

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; De Vito, M. A.; Horvath, J. E.

    ``Black widow'' systems are located in a well determined region of the plane (where is the mass of the pulsar companion and is the orbital period of the system). An attempt has been made to understand which are the mechanisms that lead to companions of ``black widows'' to be located in this region; since standard binary evolution does not provide a satisfactory response. From our evolutionary calculations; we study the path performed in the plane by a binary system to reach the state of ``black widow''. We also discuss whether there is a connection between ``redbacks'' and ``black widows''. FULL TEXT IN SPANISH

  20. Il sistema multiplo di Spica osservato dal Padre Giovanni Battista Audiffredi nel 1753

    NASA Astrophysics Data System (ADS)

    Sigismondi, Costantino

    2005-06-01

    The multiplicity of Spica's system has been first observed in 1753 by the dominican father Giovanni Battista Audiffredi through a lunar occultation. Audiffredi noted that the emersion's duration from the bright lunar limb was not instantaneous. Nowadays Spica has five known components, four of them have been discovered by occultation. This observation is presented along with a general introduction of lunar occultations, Watts' profiles, Cassini regions and grazes.

  1. Determinación de la velocidad del viento estelar en el sistema planetario HD 209458

    NASA Astrophysics Data System (ADS)

    Villarreal D'Angelo, C. S.; Schneiter, M.; Costa, A.

    In this work we propose a method to indirectly determine the velocity of the stellar wind, ve , of the G0 V star HD 209458 (M = 1, 148M ) which is known to have a transiting planet HD 209458b (M p = 0, 714MJ ). To estimate the value of the stellar wind, we simulated the problem assum- ing diferent values of ve and m p . For each model (different pairs of ve and m p ) we adjusted the value of m p to obtain the observed 5% of absorption in Ly-a for the whole line width. Then, we calculate the Ly-a absorption for different widths of the line. The best fit model is determined by comparing with the observations. FULL TEXT IN SPANISH

  2. The Solar System/El Sistema Solar--A Fully Integrated Instructional Unit.

    ERIC Educational Resources Information Center

    Van Heukelem, Tom; Mercado, Maria de Jesus

    This lesson plan for the second grade uses information on the solar system to provide science education for limited-English-proficient (LEP) students in San Diego, California. The lesson has been developed to be taught in a bilingual class, a Spanish-language immersion class, or a two-way bilingual class. Lessons are arranged so that native…

  3. Cuantificacion de la radiacion de la estructura en sistemas de caja cerrada

    NASA Astrophysics Data System (ADS)

    Segura Alcaraz, Jorge G.

    In the present work a contribution to the study of the quantification of the radiation of the structure walls in systems of closed box has been made, establishing a relation of the vibroacustic response of this type of radiating systems with the characteristics of the material used, such as the Young modulus, the damping, or the density. From a general point of view, the object of the work fits within the problems of dynamic fluid-structure interaction, so the presented foundations of the procedures and models, are similar to the used in other dominions of application, like the construction, aeronautics, naval construction, Biology, etc. In order to approach the problem, a mecano-acoustic couple between the different elements from the radiating system is considered. Ideally, in the radiating systems composed of loudspeakers mounted on an acoustic enclosure or box, the walls of the box are considerated infinitely rigid with null movement. In the reality, the experience demonstrates that the walls behave like vibrant plates under the action of the inner pressures, and contribute to the final radiation of sound of the system, mainly in the low frequencies range. To obtain the proposed objective, first a series of experimental measures has been made on models of closed box with and without loudspeaker. In the experimental procedure the vibracional behavior of the walls of the structure has been studied by means of modal analysis and measures of vibration. The acoustic response of the systems is evaluated by means of measures of acoustic pressure and intensity. Next, numerical models of the loudspeaker, inner air and structure have been implemented. The implemented numerical models are mechanical-acoustic, the electrical part of the loudspeaker has been replaced by a harmonic excitation force. The first numerical model is three-dimensional, looking for obtaining a simulation of the simultaneous interaction of the three main elements of the system: the inner air of the box, the diaphragm of the loudspeaker, and the walls of the box. Moreover another numerical model in two dimensions has been implemented, adding the air outside of the box, and obtaining a fluid-structure-fluid couple. With both models a parametric study been made. In sumary the structure colors the sonorous response of the system in all the studied frequency range, due to resonances or forced vibrations of the walls. On the other hand the proposed numerical model supposes an advance with respect to the presented ones until the moment. The model constitutes a design tool that allows to study in an economic form, the importance of the structure in the sonorous response of the system.

  4. Resonancias en la región trans-neptuniana

    NASA Astrophysics Data System (ADS)

    Gallardo, T.; Ferraz-Mello, S.

    La expansión de la órbita del planeta Neptuno en la etapa de acreción del Sistema Solar exterior (Fernández e Ip 1984, 1996) parece ser un mecanismo eficiente para la captura de planetesimales en las resonancias exteriores con Neptuno (Malhotra 1995). Por otro lado, los estudios dinámicos realizados por varios autores indican que las resonancias son regiones de evolución estable, en contraste con el comportamiento caótico del resto de la región trans-neptuniana. Por estas razones, y si bien los datos observacionales son todavía muy limitados, se supone que los objetos descubiertos se encuentran en alguna de esas resonancias. En esta comunicación presentamos un estudio analítico y numérico de las principales resonancias exteriores con Neptuno.

  5. Un gran proyecto en crisis: el estudio coordinado de la norma linguistica culta de las principales ciudades de Iberoamerica y de la peninsula Iberica (A Great Project in Crisis: the Coordinated Study of the Educated Linguistic Norm of the Principal Cities of Latin America and of the Iberian Peninsula)

    ERIC Educational Resources Information Center

    Criado de Val, Manuel

    1975-01-01

    The controversy holding back the project is what approach should be used in data collecting, controlled interviews or spontaneous recordings. The author favors the latter. To be scientific, the analysis of the data should be psycholinguistic rather than stylistic. (Text is in Spanish.) (TL)

  6. Evolución de planetas gigantes y posibilidades de su detección directa

    NASA Astrophysics Data System (ADS)

    Brunini, A.; Benvenuto, O. G.

    Desde la reciente detección de planetas gigantes orbitando estrellas cercanas de tipo solar por medio de efecto Doppler, uno de los principales problemas, en cuanto al estudio de los sistemas planetarios extrasolares, se refiere a la posibilidad de obtener evidencia directa de su existencia. Esto parece ser factible gracias a que en un futuro cercano entrarán en operación algunos telescopios especialmente adecuados a estos propósitos. Por tal motivo, hemos comenzado desde hace un tiempo un esfuerzo en cuanto al estudio de la evolución planetaria. A tales efectos hemos adaptado el código de evolución estelar de nuestro Observatorio al caso planetario. Las principales diferencias entre el caso estelar y el planetario se encuentran en la ecuación de estado. A tales fines hemos incluído la reciente ecuación de estado de Saumon, Chabrier y Van Horn, las opacidades radiativas de Guillot et al., procesos de quema de Deuterio, etc. También se ha considerado la posible existencia de fases de hielo y roca en el interior planetario. Por el momento hemos despreciado los efectos de la rotación planetaria. Con este código hemos computado la evolución de planetas con masas desde 10 hasta 0.3 masas de Júpiter. Utilizando nuestros resultados numéricos discutimos la detectabilidad de estos objetos en condiciones realistas.

  7. Distributive immunization of networks against viruses using the `honey-pot' architecture

    NASA Astrophysics Data System (ADS)

    Goldenberg, Jacob; Shavitt, Yuval; Shir, Eran; Solomon, Sorin

    2005-12-01

    Although computer viruses cause tremendous economic loss, defence mechanisms fail to adapt to their rapid evolution. Previous immunization strategies have been characterized as being static and centralized, which has made virus containment difficult or even impossible. We suggest, instead, to propagate the immunization agent as an epidemic. The main problem with epidemic vaccine propagation is that it is bound to lag behind the virus. We suggest giving the vaccine an advantage over the virus by allowing it to leapfrog through a separate, overlapping, partially correlated network. This enables the antivirus to contain the epidemic efficiently. We systemize this concept with a `honey-pot' architecture that achieves both early virus discovery and rapid antivirus dissemination. We present analytic, as well as simulation, results for a set of realistic topologies that illustrate the effectiveness of this approach.

  8. [Effect of glucuronoxylomannan of Tremella mesenterica Ritz. Fr. (Basidiomycota) on the plants resistance to tobacco mosaic virus].

    PubMed

    Kovalenko, O H; Polishchuk, O M

    2009-01-01

    It has been established that extracellular polysaccharides of Glucuronoxylomannan (GXM), which are produced by Tremella mesenterica Ritz. Fr. (Basidiomycota), has antivirus properties and can induce the resistance to TMV in hypersensitive variety of tobacco. The resistance was blocked in the presence of actinomycin D. This process confirms that resistance has been activated with GXM de novo. GXM takes influence on the early stages of viruses and host plants interaction too, which are irrespective to cells genome activation. PMID:19663328

  9. Beyond Firewalls: Professional Certification Ensures Your Staff Will Understand Information Security in Its Proper Context

    ERIC Educational Resources Information Center

    Svetcov, Eric

    2004-01-01

    When it comes to security, many people do not know what they do not know. Consider for example, an administrator who leaves her password taped under her keyboard, or a teacher who doesn't change his password (ever!) or can't be bothered to log out or lock the computer, all the firewalls and antivirus programs in the world will not protect a…

  10. An efficient synthesis of novel bis-triazole glycoconjugates via a three-component condensation as a key reaction.

    PubMed

    Cheng, Jie; Gu, Zhenlong; He, Caiyu; Jin, Jie; Wang, Lijun; Li, Guojun; Sun, Bei; Wang, Hui; Bai, Jun

    2015-09-23

    Novel bis-triazole glycoconjugates were designed and prepared successfully via 5 steps from propargyl per-O-acetyl-β-d-glucoside or xyloside (total yield of 48-53%), after utilizing a three-component condensation of propargyl per-O-acetyl-β-d-glycoside, formaldehyde, and sodium azide as a key step to synthesize 2-hydroxymethyl-2H-1,2,3-triazole glycoconjugates. The developed bis-triazole glycoconjugates would be crucial in antivirus pharmacology and chemical biology. PMID:26257377

  11. Modelos autoconsistentes de sistemas estelares cuspidales y triaxiales con distribución de velocidades casi isotrópica

    NASA Astrophysics Data System (ADS)

    Carpintero, D. D.; Muzzio, J. C.; Navone, H. D.; Zorzi, A. F.

    It has been shown in many works that it is possible to build stable, self-consistent models of triaxial stellar systems, even with cusps, and containing high percentages of chaotic orbits. Since all these models have been obtained from cold collapses, their velocity distributions are strongly radial. Also, chaos was computed using either Lyapunov exponents or SALI. However, models obtained by adiabatic deformation of spherical systems, in which the velocity distribution is more isotropic, showed a very low level of chaos, though it must be noted that the method of detecting chaos used in this case, namely the variation of orbital frequencies, is less sensitive than the abovementioned methods. In this work, we present models obtained by adiabatic deformation, in which we compute the fraction of chaotic orbits using both Lyapunov exponents and variation of orbital frequencies. Our results show that the percentages of chaotic orbits is significant, though they are smaller than those obtained in models with strong radial velocity components. FULL TEXT IN SPANISH

  12. Estudio fotométrico de sistemas binarios y multiples de cumulos estelares de la Nube Mayor de Magallanes

    NASA Astrophysics Data System (ADS)

    Palma, T.; Clariá, J. J.; Geisler, D.; Ahumada, A. V.

    We study 11 probable binary or multiple systems of star clusters (SCs) of the Large Magellanic Cloud. They are formed by 31 SCs; out of which 19 have been observed in the Washington system with the Cerro Tololo ``Victor Blanco'' 4m telescope. We confirm a high probability of physical reality for some of the studied binary or multiple system candidates. We also determine their probable formation epochs and show that some of them could not be genuine physical systems. In all cases we recommend to confirm the physical association of these SC systems by examining their heliocentric distances and relative radial velocities. FULL TEXT IN SPANISH

  13. Sistemas de Cúmulos Globulares: trazando la formación y evolución de las galaxias

    NASA Astrophysics Data System (ADS)

    Faifer, F. R.

    In this paper; we review some properties and mentioned several aspects that have caused a marked and renewed interest in the study of globular cluster systems in the last decade. We emphasised on the relationship between some of these properties and galaxies formation processes. FULL TEXT IN SPANISH

  14. Cuerpo de Paz Manual de Sistema de Programacion y Capacitacion (Peace Corps Programming and Training System Manual): T0063.

    ERIC Educational Resources Information Center

    Peace Corps, Washington, DC.

    This Spanish version of the Peace Corps Programming and Training System Manual is designed to help field staff members of the Peace Corps train volunteers. Its task descriptions, guidelines, examples, and definitions are intended to be practical and informative rather than restrictive. The manual is divided into six major sections: (1)…

  15. Study of apsidal motion in massive close binary systems. (Spanish Title: Estudio del movimiento apsidal en sistemas binarios masivos)

    NASA Astrophysics Data System (ADS)

    Ferrero, G.; Gamen, R.; Fernández-Lajús, E.

    In O+OB close binary systems, superior order momenta of the classical gravitational potential and general relativity effects produce a secular motion of the apsides. This phenomenon, together with theoretical stellar structure models, can be used to estimate the absolute masses of the system components, even for non-eclipsing binaries. We are conducting a spectroscopic study of eccentric close O+OB binaries in order to detect or confirm the existence of apsidal motion, determine its rate, and calculate the absolute masses of the stars. In this work we describe the current status of the project and present some preliminary results obtained for the systems iota Ori A, HD 93205, HD 152248, and HD 165052.

  16. Sistemas Eolicos Pequenos para Generacion de Electridad (Spanish version of Small Wind Electric Systems: A U.S. Consumer's Guide)

    SciTech Connect

    Not Available

    2005-07-01

    This Spanish version of the popular Small Wind Electric Systems: A U.S. Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  17. Sistema Solar: de la observación de La Tierra a los planetas gigantes y sus lunas

    NASA Astrophysics Data System (ADS)

    Rodrigo, R.

    La fotoquímica tiene un papel principal en la composición de las atmósferas planetarias. Se examinan diferentes procesos fotoquímicos tanto para atmósferas oxidadas como reductoras, poniendo un especial énfasis en los ciclos químicos más importantes. En este sentido, se presentan diferentes ciclos químicos capaces de producir hidrocarbonos y nitrilos en atmósferas reductoras, así como aquellos capaces de mantener las proporciones de mezcla de las moléculas que contienen oxígeno, tales como CO2, O2 y H2O. También se analizan otros procesos importantes tales como la condensación y procesos de sputtering y de sublimación que han de tenerse en cuenta cuando se realizan modelos sobre la composición atmosférica.

  18. Estudio general de la region del Lago Titicaca evaluando en forma preliminar un sistema de analisis interactivo de imagenes multiespectrales

    USGS Publications Warehouse

    Brockmann, C.E.; Carter, William D.

    1976-01-01

    ERTS-1 digital data in the form of computer compatible tapes provide the geoscientist with an unusual opportunity to test the maximum flexibility of the satellite system using interactive computers, such as the General Electric Image 100 System. Approximately 9 hours of computer and operator time were used to analyze the Lake Titicaca image, 1443-14073, acquired 9 October 1973. The total area of the lake and associate wetlands was calculated and found to be within 3 percent of previous measurements. The area was subdivided by reflectance characteristics employing cluster analysis of all 4 bands and later compared with density values of band 4. Reflectance variations may be attributed to surface roughness, water depth and bottom characteristics, turbidity, and floating matter. Wetland marsh vegetation, vegetation related to ground-water effluents, natural grasses, and farm crops were separated by cluster analysis. Sandstone, limestone, sand dunes, and several volcanic rock types were similarly separated and displayed by assigned colors and extended through the entire scene. Waste dumps of the Matilde Zinc Mine and smaller mine workings were tentatively identified by signature analysis. Histograms of reflectance values and map printouts were automatically obtained as a record of each of the principal themes. These themes were also stored on a work tape for later display and photographic record as well as to serve in training. The Image 100 System is rapid, extremely flexible and very useful to the investigator in identifying subtle features that may not be noticed by conventional image analysis. The entire scene, which covers 34,225 km2, was analyzed at a scale of 1:600,000, and portions at 1:98,000 and 1:25,000, during a 9-hour period at a rental cost of $250 per hour. Costs to the user can be reduced by restricting its uses to specific areas, objectives, and procedures, rather than undertaking a complete analysis of a total scene.

  19. Cinemática de sistemas interactuantes de tipo M51: Relación de Tully-Fisher

    NASA Astrophysics Data System (ADS)

    Gúnthardt, G.; Díaz, R. J.

    We present heliocentric radial velocity distributions of six M51-type galaxies. Additionally we present Tully-Fisher relations for M51-type systems from our kinematic catalog (Gunthardt et al. 2006) with the velocities determined from H-alpha and using B-band absolute magnitudes; we also considered systems with maximum velocities from HI lambda-21 cm line. In both cases, we found shallower relations compared with nearby spiral galaxies, in agreement with the results found by Reshetnikov & Klimanov (2003). FULL TEXT IN SPANISH

  20. Alternancia entre el estado de emisión de Rayos-X y Pulsar en Sistemas Binarios Interactuantes

    NASA Astrophysics Data System (ADS)

    De Vito, M. A.; Benvenuto, O. G.; Horvath, J. E.

    2015-08-01

    Redbacks belong to the family of binary systems in which one of the components is a pulsar. Recent observations show redbacks that have switched their state from pulsar - low mass companion (where the accretion of material over the pulsar has ceased) to low mass X-ray binary system (where emission is produced by the mass accretion on the pulsar), or inversely. The irradiation effect included in our models leads to cyclic mass transfer episodes, which allow close binary systems to switch between one state to other. We apply our results to the case of PSR J1723-2837, and discuss the need to include new ingredients in our code of binary evolution to describe the observed state transitions.

  1. Influencia de diferentes ecuaciones de transformacion del sistema UBVal RGU en el estudio fotometrico de cumulos galacticos.

    NASA Astrophysics Data System (ADS)

    Huestamendia Aparicio, G.

    Three-colour photometry of ten open clusters in the RGU system has been carried out. The calibration sequence has been defined using the Buser's transformation equations between the UBV and RGU systems, while in earlier works the Steinlin's formulae have been used. The results have been compared with those given in these works. Some differences have been found in G, G-R and U-G as a function of the spectral type and the interstellar absorption. They have a systematic character.

  2. Life Support Systems. Environment Booklet 1. Teacher's Edition=Sistemas vitales. Libro del medio ambiente 1. Manual para El Maestro.

    ERIC Educational Resources Information Center

    California State Univ., Los Angeles. National Dissemination and Assessment Center.

    The booklet is part of a grade 10-12 social studies series produced for bilingual education. The series consists of six major thematic modules, with four to five booklets in each. The interdisciplinary modules are based on major ideas and designed to help students understand some major human problems and make sound, responsive decisions to improve…

  3. The use of climatic parameters and indices in vegetation distribution. A case study in the Spanish Sistema Central.

    PubMed

    Gavilán, Rosario G

    2005-11-01

    In this study, over 100 phytoclimatic indices and other climatic parameters were calculated using the climatic data from 260 meteorological stations in a Mediterranean territory located in the centre of the Iberian Peninsula. The nature of these indices was very different; some of them expressed general climatic features (e.g. continentality), while others were formulated for different Mediterranean territories and included particular limits of those indices that expressed differences in vegetation distribution. We wanted to know whether all of these indices were able to explain changes in vegetation on a spatial scale, and whether their boundaries worked similarly to the original territory. As they were so numerous, we investigated whether any of them were redundant. To relate vegetation to climate parameters we preferred to use its hierarchical nature, in discrete units (characterized by one or more dominant or co-dominant species), although it is known to vary continuously. These units give clearer results in this kind of phytoclimatic study. We have therefore used the main communities that represent natural potential vegetation. Multivariate and estimative analyses were used as statistical methods. The classification showed different levels of correlation among climatic parameters, but all of them were over 0.5. One hundred and eleven parameters were grouped into five larger groups: temperature (T), annual pluviothermic indices (PTY), summer pluviothermic indices (SPT), winter potential evapotranspiration (WPET) and thermal continentality indices (K). The remaining parameters showed low correlations with these five groups; some of them revealed obvious spatial changes in vegetation, such as summer hydric parameters that were zero in most vegetation types but not in high mountain vegetation. Others showed no clear results. For example, the Kerner index, an index of thermal continentality, showed lower values than expected for certain particular types of vegetation. Parameters relating to the water balance turned out to be very discriminative for separating vegetation types according to the season or the month when water begins to be scarce. Thus, water availability in soils is a limiting factor for the development of vegetation in spring or autumn as well as in summer. As expected, precipitation and temperature discriminated the altitudinal levels of vegetation. Finally, these index limits only worked in the territories where they were formulated, or in nearby areas. PMID:15997399

  4. La producción de cráteres en el Sistema de Satélites de Saturno

    NASA Astrophysics Data System (ADS)

    Zanardi, M.; Di Sisto, R. P.

    The saturnian satellite system has been observed by the Cassini-Huygens mission, in particular the impact craters on them. These satellites present a diversity of surfaces which could help us to understand about their history. To study the production of craters on these satellites, we develop a theoretical model from previous simulations and we obtain the contribution of Centaur objects to the production of craters. We calculate the number of craters for a given size and the greatest crater produced by Centaur objects. This allowed us to compare our theoretical results with the observations by the Cassini-Huygens and determine the origin of craters as well as constrain the size distribution of Centaurs. FULL TEXT IN SPANISH

  5. Efectos difusivos en la formación de enanas blancas de Helio de baja masa en sistemas binarios cerrados

    NASA Astrophysics Data System (ADS)

    De Vito, M. A.; Benvenuto, O. G.

    In the last years, and thanks to advances in observational techniques, many astronomers have discovered in a great number of binary radio-pulsars the presence of a helium white dwarf resulting from a previous evolutionary state in which the progenitor of this star experienced one or more episodes of mass transfer to the compact component in the pair. That is the case for PSR B1855+09 (van Kerkwijk, M. H., Bell, J. F, Kaspi, V. M., & Kulkarni, S. R. 2000, ApJ 530, L37), where the mass for the white dwarf is known accurately from measurements of the Shapiro delay of the pulsar signal, MWD = 0.258+0.028-0.016 M⊙; for PSR J02018 + 4232 (Bassa, C. G., van Kerkwijk, M. H., & Kulkarni, S. R. 2003, A&A, 403, 1067), the spectra confirm that the companion is a helium-core white dwarf of ≈ 0.2 M⊙. On the other hand, there are several authors (Ferraro, F., Possenti, A., Sabbi, E., & D'Amico, N. 2003, ApJ, 596, L211; Bassa et al. 2003) that have identified the optical binary companion to the BMSP PSR J1911 - 5958A, located in the halo of the Galactic globular cluster NGC 6752, like a blue star whose position in the color-magnitude diagram is consistent with the cooling sequence of a low-mass, ≈ 0.17 - 0.20 M⊙, low metallicity helium white dwarf at the cluster distance. Finally, the color and magnitude of the stellar companion for B 1620-26 indicate that is a white dwarf of 0.34 ± 0.04 M⊙ (Sigurdson, S., Richer, H. B., Hansen, B. M., Stairs, I. H. & Thorset, S. E. 2003, Science, 301, 193S). This has motivated us to study the formation of low mass helium white dwarfs in the context of binary evolution. For that purpose, using the code of binary evolution, entirely developed in the Facultad de Ciencias Astronómicas y Geofísicas of the Universidad Nacional de La Plata, Argentina, we have investigated the effects of diffusive processes on the evolution of a star member of a close binary system. A similar study was performed for Althaus, L. G., Serenelli, A. M., & Benvenuto, O. G. (2001, MNRAS, 323, 471) but in that paper the mass transfer was mimicked by subtracting mass to a progenitor of 1 M⊙ to obtain the mass for the desired object. Actually, our binary code has a full nuclear reactions network for hydrogen and helium burning that allowed us to follow the abundances of fifteen isotopes throughout the entire evolution of the star. We have also included a detailed equation of state. The mass loss treatment is non conservative. We have modified the conditions for the beginning and end of mass transfer episodes. In our previous version, we assumed it to occur when the stellar radius was greater or smaller, respectively, that the Roche Lobe radius for the star. This introduced numerical problems, especially at the end of mass transfer phases. We adopted H. Ritter (1988, A&A, 202, 93) formulation that considers a finite scale height in the stellar atmosphere. The numerical behaviour in much more satisfactory, besides that it constitutes a more appropriate description for the physical problem. We perform the calculations for the evolution of the primary star in a close binary system of initial mass 2 M⊙, initial period of 1 day, initial mass ratio of 1.4142 and solar metallicity. We have done the calculations in four cases: A) with diffusion and all Roche Lobe overflows, B) with diffusion and only the first Roche Lobe overflow, C) without diffusion and all Roche Lobe overflows, D) without diffusion and only the first Roche Lobe overflow. Cases B) and D) where performed to compare with results obtained for Althaus et al. (2001). The main conclusion of this work is that the age of these objects is mainly determined by diffusive effects, and the late stages of mass transfer, not considered in Althaus et al. (2001), constituted a minor effect on the scales of cooling times.

  6. Exe-Guard Project

    SciTech Connect

    Smith, Rhett; Marshall, Tim; Chavez, Adrian; Bratus, Sergey

    2015-12-26

    The exe-Guard Project is an alliance between Dominion Virginia Power (DVP), Sandia National Laboratories (SNL), Dartmouth University, and Schweitzer Engineering Laboratories (SEL). SEL is primary recipient on this project. The exe-Guard project was selected for award under DE-FOA-0000359 with CFDA number 81.122 to address Topic Area of Interest 4: Hardened platforms and Systems. The exe-Guard project developed an antivirus solution for control system embedded devices to prevent the execution of unauthorized code and maintain settings and configuration integrity. This project created a white list antivirus solution for control systems capable of running on embedded Linux® operating systems. White list antivirus methods allow only credible programs to run through the use of digital signatures and hash functions. Once a system’s secure state is baselined, white list antivirus software denies deviations from that state because of the installation of malicious code as this changes hash results. Black list antivirus software has been effective in traditional IT environments but has negative implications for control systems. Black list antivirus uses pattern matching and behavioral analysis to identify system threats while relying on regular updates to the signature file and recurrent system scanning. Black list antivirus is vulnerable to zero day exploits which have not yet been incorporated into a signature file update. System scans hamper the performance of high availability applications, as revealed in NIST special publication 1058 which summarizes the impact of blacklist antivirus on control systems: Manual or “on-demand” scanning has a major effect on control processes in that they take CPU time needed by the control process (Sometimes close to 100% of CPU time). Minimizing the antivirus software throttle setting will reduce but not eliminate this effect. Signature updates can also take up to 100% of CPU time, but for a much shorter period than a typical manual scanning process. Control systems are vulnerable to performance losses if off-the-shelf blacklist antivirus solutions aren’t implemented with care. This investment in configuration in addition to constant decommissioning to perform manual signature file updates is unprecedented and impractical. Additionally, control systems are often disconnected or islanded from the network making the delivery of signature updates difficult. Exe-Guard project developed a white list antivirus solution that mitigated the above drawbacks and allows control systems to cost-effectively apply malware protection while maintaining high reliability. The application of security patches can also be minimized since white listing maintains constant defense against unauthorized code execution. Security patches can instead be applied in less frequent intervals where system decommissioning can be scheduled and planned for. Since control systems are less dynamic than IT environments, the feasibility of maintaining a secure baselined state is more practical. Because upgrades are performed in infrequent, calculated intervals, it allows a new security baseline to be established before the system is returned to service. Exe-Guard built on the efforts of SNL under the Code Seal project. SNL demonstrated prototype Trust Anchors on the project which are independent monitoring and control devices that can be integrated into untrustworthy components. The exe-Guard team started with the lessons learned under this project then designed commercial solution for white list malware protection. Malware is a real threat, even on islanded or un-networked installations, since operators can unintentionally install infected files, plug in infected mass storage devices, or infect a piece of equipment on the islanded local area network that can then spread to other connected equipment. Protection at the device level is one of the last layers of defense in a security-in-depth defense model before an asset becomes compromised. This project provided non-destructive intrusion, isolation and automated response solution, achieving a goal of the Department of Energy (DOE) Roadmap to Secure Control Systems. It also addressed CIP-007-R4 which requires asset owners to employ malicious software prevention tools on assets within the electronic security perimeter. In addition, the CIP-007-R3 requirement for security patch management is minimized because white listing narrows the impact of vulnerabilities and patch releases. The exe-Guard Project completed all tasks identified in the statement of project objective and identified additional tasks within scope that were performed and completed within the original budget. The cost share was met and all deliverables were successfully completed and submitted on time. Most importantly the technology developed and commercialized under this project has been adopted by the Energy sector and thousands of devices with exe-Guard technology integrated in them have now been deployed and are protecting our power systems today

  7. GPS, punto de contacto entre la Astronomía y otras disciplinas

    NASA Astrophysics Data System (ADS)

    Perdomo, R.

    En los primeros años de la pasada década, un grupo de Astrónomos de La Plata iniciaron trabajos de investigación en Geodesia Satelital. En esta presentación se propone repasar sus principales logros y situarlos en el contexto del desarrollo de la disciplina a nivel mundial. Por entonces las aplicaciones prácticas de la disciplina eran indirectas y solo evidentes para los especialistas. Los errores del Posicionamiento Satelital eran de varios metros y en posicionamiento relativo, del orden de medio metro. Estos resultados se lograban al cabo de varios días de medición continuada. En los años siguientes, el sistema GPS alcanzó su nivel operacional y produjo una revolución tanto en lo relacionado con los tiempos de medición como con las precisiones. El grupo de La Plata se desarrolló simultáneamente con GPS, lo que posibilitó su participación actual en diversos temas vigentes: aplicaciones de alta precisión para la materialización de sistemas terrestres de referencia, monitoreo de movimientos de la corteza, contribución con servicios internacionales para la determinación de movimientos tectónicos globales y regionales, monitoreo de la ionósfera a partir de la propagación de las señales, determinación de la ondulación del geoide a escala local, etc. También se generaron muchas aplicaciones prácticas algunas en tiempo real: navegación, apoyo a imágenes aéreas o satelitales, aplicaciones a la agricultura, catastro y ordenamiento territorial, apoyo a relevamientos geofísicos, etc.

  8. Determinacion de Caracteristicas Opticas del Telescopio OAN150

    NASA Astrophysics Data System (ADS)

    Galan, M. J.; Cobos, F. J.

    1987-05-01

    En el Observatorio de Calar Alto, en Almería, España, está ubicado un telescopio de 15O-cms de diámetro -construído por REOSC- perteneciente al Observatorio Astronómico Nacional, con sede en Madrid, España. La infraestructura técnica del OAN ha sido tradicionalmente débil y actualmente se está haciendo un esfuerzo por fortalecerla. Existe una información muy limitada del telescopio en general; de su óptica en particular se conocían los valores de los parámetros principales pero sin saber si éstos corresponden a valores teóricos ó de construcción. Por ello se consideró necesario iniciar una investigación para conocer en detalle los valores reales de las componentes ópticas del telescopio, obteniéndose algunos resultados de interés. El primario del telescopio OANl5O es aproximadamente F/3 y el siste ma en su conjunto es F/8.2, con su sistema corrector de campo. En términos generales, la imagen es satisfactoria en todo el campo y, sin sistema corrector, la imagen axial también es buena. En un futuro muy cercano se piensa diseñar instrumentación adicional para este telescopio. Conocer con mayor precisión sus características puede ser de gran utilidad para tal fin, pues se efectúan los cálculos considerando conjuntamente al telescopio y al instrumento.

  9. Incentivos para atraer y retener personal de salud de zonas rurales del Perú: un estudio cualitativo

    PubMed Central

    Huicho, Luis; Canseco, Francisco Díez; Lema, Claudia; Miranda, J. Jaime; Lescano, Andrés G.

    2014-01-01

    El objetivo fue identificar incentivos de atracción y retención en zonas rurales y distantes de Ayacucho, Perú. Fueron realizadas entrevistas en profundidad con 80 médicos, enfermeras, obstetras y técnicos (20 por grupo) de las zonas más pobres y con 11 funcionarios. No existen políticas sistemáticas de atracción y retención de personal de salud en Ayacucho. Los principales incentivos, en orden de importancia, fueron mejoras salariales, oportunidades de formación y capacitación, estabilidad laboral y nombramiento, mejoras en infraestructura y equipos, e incremento del personal. Se mencionaron también mejoras en la vivienda y alimentación, mayor cercanía con la familia y reconocimiento por el sistema de salud. Existen coincidencias y singularidades entre los distintos grupos sobre los incentivos clave para estimular el trabajo rural, que deben considerarse al diseñar políticas públicas. Las iniciativas del Estado deben comprender procesos rigurosos de monitoreo y evaluación, para asegurar que las mismas tengan el impacto deseado. PMID:22488318

  10. Evaluation of Tools for Protection of Interest against Hacking and Cracking

    NASA Astrophysics Data System (ADS)

    Jahankhani, Hossein; Antonijevic, Branko; Walcott, Terry

    The internet considered a tool that effectively ensures communication globally has been hindered by hackers and crackers continuously. In so doing, a multitude of network facilitated tools such as firewalls, virtual private networks (VPN) and a variety of antivirus software packages has been enabled for dealing with such predicaments. However, more often than not these facilitated tools are marketed as perfect solutions to the ever culminating problems such as loss of data and privacy in networked and world wide intercommunications. We provide a forum for addressing these perceived problems in this paper.

  11. Stability and Hopf Bifurcation for a Delayed SLBRS Computer Virus Model

    PubMed Central

    Yang, Huizhong

    2014-01-01

    By incorporating the time delay due to the period that computers use antivirus software to clean the virus into the SLBRS model a delayed SLBRS computer virus model is proposed in this paper. The dynamical behaviors which include local stability and Hopf bifurcation are investigated by regarding the delay as bifurcating parameter. Specially, direction and stability of the Hopf bifurcation are derived by applying the normal form method and center manifold theory. Finally, an illustrative example is also presented to testify our analytical results. PMID:25202722

  12. [Advances in research of chemical constituents and pharmacological activites of Ephedra].

    PubMed

    Ding, Li-Li; Shi, Song-Shan; Cui, Jian; Wang, Shun-Chun; Wang, Zheng-Tao

    2006-10-01

    The collected information is an attempt to cover the more recent developments in the phytochemistry and pharmacology of this genus. During the past years, alkaloids, flavonoids, volatile oils, organic acids, polysaccharides, tannins and phenolic constituents have been isolated from Ephedra. Pharmacological studies are described according to hypoglycemic effects, anticoagulated blood properties, depressurization, immunosuppressive activity, antioxidation and antivirus activity and so on. The information summarized here is intended to provid a rational foundation for the futher development and utilization of Ephedra which is rich in China. PMID:17225527

  13. Stability and Hopf bifurcation for a delayed SLBRS computer virus model.

    PubMed

    Zhang, Zizhen; Yang, Huizhong

    2014-01-01

    By incorporating the time delay due to the period that computers use antivirus software to clean the virus into the SLBRS model a delayed SLBRS computer virus model is proposed in this paper. The dynamical behaviors which include local stability and Hopf bifurcation are investigated by regarding the delay as bifurcating parameter. Specially, direction and stability of the Hopf bifurcation are derived by applying the normal form method and center manifold theory. Finally, an illustrative example is also presented to testify our analytical results. PMID:25202722

  14. Identification of Malicious Web Pages by Inductive Learning

    NASA Astrophysics Data System (ADS)

    Liu, Peishun; Wang, Xuefang

    Malicious web pages are an increasing threat to current computer systems in recent years. Traditional anti-virus techniques focus typically on detection of the static signatures of Malware and are ineffective against these new threats because they cannot deal with zero-day attacks. In this paper, a novel classification method for detecting malicious web pages is presented. This method is generalization and specialization of attack pattern based on inductive learning, which can be used for updating and expanding knowledge database. The attack pattern is established from an example and generalized by inductive learning, which can be used to detect unknown attacks whose behavior is similar to the example.

  15. Malware distributed collection and pre-classification system using honeypot technology

    NASA Astrophysics Data System (ADS)

    Grégio, André R. A.; Oliveira, Isabela L.; Santos, Rafael D. C.; Cansian, Adriano M.; de Geus, Paulo L.

    2009-04-01

    Malware has become a major threat in the last years due to the ease of spread through the Internet. Malware detection has become difficult with the use of compression, polymorphic methods and techniques to detect and disable security software. Those and other obfuscation techniques pose a problem for detection and classification schemes that analyze malware behavior. In this paper we propose a distributed architecture to improve malware collection using different honeypot technologies to increase the variety of malware collected. We also present a daemon tool developed to grab malware distributed through spam and a pre-classification technique that uses antivirus technology to separate malware in generic classes.

  16. [Advance of studies on bioactivity of flavonoid-metal complexes].

    PubMed

    Liu, Yanji; He, Xiaoyan; Zuo, Hua; Zhang, Qixiong; Li, Zhubo; Shi, Lunyong

    2012-07-01

    The flavonoid-metal complexes showed obviously stronger bioactivities such as antibiosis, antivirus, anti-inflammatory, anti-tumor and anti-free-radical, possibly because of the stronger binding force caused by the change in complex structure and accessibility to target spots, or the synergy effect between flavonoids and metallic ions. This essay summarizes studies on bioactivity and mechanism of flavonoid-metal complexes, in order to provide reference for in-depth study and development on effective constituents contained in flavonoid traditional Chinese medicines. PMID:23019867

  17. Design and Implementation of a Secure Modbus Protocol

    NASA Astrophysics Data System (ADS)

    Fovino, Igor Nai; Carcano, Andrea; Masera, Marcelo; Trombetta, Alberto

    The interconnectivity of modern and legacy supervisory control and data acquisition (SCADA) systems with corporate networks and the Internet has significantly increased the threats to critical infrastructure assets. Meanwhile, traditional IT security solutions such as firewalls, intrusion detection systems and antivirus software are relatively ineffective against attacks that specifically target vulnerabilities in SCADA protocols. This paper describes a secure version of the Modbus SCADA protocol that incorporates integrity, authentication, non-repudiation and anti-replay mechanisms. Experimental results using a power plant testbed indicate that the augmented protocol provides good security functionality without significant overhead.

  18. Analysis of the maximum discharge of karst springs

    NASA Astrophysics Data System (ADS)

    Bonacci, Ognjen

    2001-07-01

    Analyses are presented of the conditions that limit the discharge of some karst springs. The large number of springs studied show that, under conditions of extremely intense precipitation, a maximum value exists for the discharge of the main springs in a catchment, independent of catchment size and the amount of precipitation. Outflow modelling of karst-spring discharge is not easily generalized and schematized due to numerous specific characteristics of karst-flow systems. A detailed examination of the published data on four karst springs identified the possible reasons for the limitation on the maximum flow rate: (1) limited size of the karst conduit; (2) pressure flow; (3) intercatchment overflow; (4) overflow from the main spring-flow system to intermittent springs within the same catchment; (5) water storage in the zone above the karst aquifer or epikarstic zone of the catchment; and (6) factors such as climate, soil and vegetation cover, and altitude and geology of the catchment area. The phenomenon of limited maximum-discharge capacity of karst springs is not included in rainfall-runoff process modelling, which is probably one of the main reasons for the present poor quality of karst hydrological modelling. Résumé. Les conditions qui limitent le débit de certaines sources karstiques sont présentées. Un grand nombre de sources étudiées montrent que, sous certaines conditions de précipitations extrêmement intenses, il existe une valeur maximale pour le débit des sources principales d'un bassin, indépendante des dimensions de ce bassin et de la hauteur de précipitation. La modélisation des débits d'exhaure d'une source karstique n'est pas facilement généralisable, ni schématisable, à cause des nombreuses caractéristiques spécifiques des écoulements souterrains karstiques. Un examen détaillé des données publiées concernant quatre sources karstiques permet d'identifier les raisons possibles de la limitation de l'écoulement maximal: (1) la dimension limitée du conduit karstique, (2) l'écoulement en charge, (3) le débordement dans un autre bassin, (4) le débordement du réseau s'écoulant vers la source principale par des sources temporaires dans le même bassin, (5) le stockage d'eau dans la zone surmontant l'aquifère karstique ou la zone épikarstique du bassin, et (6) des facteurs tels que le climat, le sol et le couvert végétal, l'altitude et la géologie du bassin d'alimentation. Le phénomène de capacité limitée du débit maximal des sources karstiques n'est pas pris en compte dans la modélisation des processus de précipitation-ruissellement, ce qui est probablement une des principales raisons de l'actuelle médiocre qualité de la modélisation hydrologique du karst. Resumen. Se presenta un análisis de las condiciones que limitan la descarga de algunos manantiales kársticos. Un elevado número de los manantiales estudiados muestra que, bajo condiciones de precipitación extremadamente intensa, hay un valor máximo para la descarga de los manantiales principales de la cuenca, independientemente del tamaño de ésta y del volumen de precipitación. La modelación de la descarga de manantiales kársticos no es fácil de generalizar y esquematizar debido a la existencia de numerosas características que son inherentes a los sistemas kársticos de flujo. A partir del estudio detallado de los datos publicados sobre cuatro manantiales kársticos, se identificó las posibles causas de la existencia de un caudal máximo de descarga: (1) el tamaño limitado del conducto kárstico, (2) el caudal surgente, (3) la descarga a otras cuencas, (4) el desbordamiento del sistema de flujo principal hacia manantiales intermitentes dentro de la misma cuenca, (5) el almacenamiento de agua en la zona superior del acuífero kárstico o zona epikárstica de la cuenca, y (6) factores tales como el clima, suelo y cubierta vegetal, y la altitud y geología de la zona de captación. La limitación de la descarga máxima de los manantiales kársticos no ha sido incluida en la modelación del proceso lluvia-escorrentía, hecho que probablemente es esencial para explicar los resultados poco satisfactorios de la modelación hidrológica de sistemas kársticos.

  19. Osnovi polojenia na reformata v obrasovatelnata sistema na Narodna republika Bulgaria (Basic Provisions of the Reform of the Public Education System in the People's Republic of Bulgaria).

    ERIC Educational Resources Information Center

    Bulgarian Communist Party, Sofia.

    This document is an English language abstract (approximately 1,500 words) of the reform provisions of the Bulgarian education system as formulated by the Bulgarian Communist Party in 1969. These reforms include the following items: access to compulsory secondary education for all; enrollment of all six-year olds; teachers to be specialized from…

  20. Work-related mental disorders and their inclusion in health policies in the Brazilian Unified Health System (Sistema Único de Saúde).

    PubMed

    Cocchiola-Silva, Rafaela A

    2016-03-01

    This study discusses the inclusion of mental disorders as work-related diseases in occupational health policies in Brazil. Mental disorders first appeared as a group of occupational diseases in 1999. Establishing mental disorders as occupational diseases was a result of the confluence of several factors: a broader notion of health, a positive shift in public perception regarding preconceived judgements relating to mental disorders and the improvement in the process that defines social security benefit entitlements due to the implementation of a new methodology in 2007. PMID:26987833

  1. Tracking and Treating Mobile Populations. The TB Net System. Migrant Clinicians Network Monograph Series. = El Sistema de Red para la TB.

    ERIC Educational Resources Information Center

    Migrant Clinicians Network, Inc., Austin, TX.

    A comprehensive tracking and referral network that helps provide continuity of care for mobile populations with active tuberculosis (TB) or TB infection is considered essential for effective treatment of TB. However, the interstate referral system that exists between state health departments has been highly inefficient for serving migrant…

  2. El sistema fonologico del dialecto judeo-espanol de Bulgaria (The Phonological System of the Judeo-Spanish Dialect of Bulgaria)

    ERIC Educational Resources Information Center

    Kanchev, Ivan V.

    1974-01-01

    The phonetics and phonological system of the Bulgarian Judeo-Spanish dialect is discussed, showing its similarities to and borrowings from modern Spanish and Bulgarian. Treatment of phonemes is analyzed in detail. (Text is in Spanish.) (CK)

  3. A Handbook for Title I Migrant Parent Advisory Councils: Understanding the System=Un Folleto Para los Concilios de Padres Titulo I Migrante: Entendiendo el Sistema.

    ERIC Educational Resources Information Center

    Arredondo, C.; And Others

    A bilingual handbook for Title I migrant Parent Advisory Councils (PACs) was designed to be used by administrators, teachers, consultants and parents in organizing and training PACs at local, district, and state levels. All information is duplicated in separate English and Spanish sections. The first part discusses the Texas migrant program,…

  4. Predlog teza o razvoju i usavrsavanju sistema obrazovanja i vaspitanja u SFRJ (Proposals for the Development and Advancement of the System of Education in Yugoslavia).

    ERIC Educational Resources Information Center

    Federal Assembly of the Socialist Federal Republic of Yugoslavia, Belgrade,

    This document is an English-language abstract (approximately 1,500 words) of a draft setting out an education system for Yugoslavia to be considered by the Federal Assembly. The proposals are divided into six chapters: (1) current trends and developments in education; (2) socioeconomic foundations of educational development; (3) changes in the…

  5. Sistemas de Documentacion e Informacion Educativa en Belgica, Paises Bajos y Francia (Educational Documentation and Information Systems in Belgium, Holland, and France).

    ERIC Educational Resources Information Center

    Rossi Etchelouz, Nelly Yvis

    This booklet describes the working and organization of the information and documentation systems in Belgium, the Netherlands, and France. The discussion begins with a look at the Belgium educational system and how information services operate within that system. The central library, specialized services, and specialized information centers are all…

  6. Calibración de isócronas semi-empíricas en el sistema fotométrico de Washington

    NASA Astrophysics Data System (ADS)

    Perren, G.; Piatti, A. E.; Vázquez, R.

    We have compiled a database of star clusters observed in the Washington photometric system composed of more than 180 objects; covering a wide range of ages. Through a systematic study of their sequences in the Color-Magnitude Diagram we plan to obtain; for the first time; a set of semi-empirical isochrones in this system. FULL TEXT IN SPANISH

  7. PLANEACION MULTIOBJETIVO EN LOS DISTRITOS DE RIEGO EN MEXICO. APLICACION DE UN SISTEMA DE AUXCLIO PARA LA TOMA DE DECISIONES 1817

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The problem of agreement among interests in the management of natural resources is complex with interactions difficult of measure. Watershed users have several objectives that impact in the short run the environment. Multiobjective decision theory considers interests, options and impacts of possible...

  8. Sistemas Eólicos Pequeños para Generación de Electricidad: Una guia para consumidores en Nuevo México

    SciTech Connect

    Not Available

    2005-10-01

    This Spanish version of the popular Small Wind Electric Systems: A New Mexico Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.

  9. Estudio del sistema de cúmulos globulares de la galaxia lenticular NGC6861: en busca de evidencias de una fusión.

    NASA Astrophysics Data System (ADS)

    Escudero, C. G.; Faifer, F. R.; Bassino, L. P.; Calderón, J. P.; Caso, J. P.

    We present a photometric study of the globular cluster system (GCS); associated to the lenticular galaxy NGC6861. It is based on GEMINI/GMOS images in the filters g'; r'; i' of three fields; one of them centered on the galaxy. Studying the colour-magnitude diagram of the system; we detect the presence of at least two populations of GCs (``blue'' and ``red'') and the presence of the phenomenon known as ``blue-tilt''. However; analyzing the colour distribution we infer the existence of a third population with intermediate colours which could be interpreted as evidence of a past interaction or fusion event. FULL TEXT IN SPANISH

  10. Sistema de cúmulos globulares de la galaxia lenticular NGC 6861: en busca de indicios sobre la formación de las S0s.

    NASA Astrophysics Data System (ADS)

    Escudero, C. G.; Faifer, F. R.; Bassino, L. P.; Calderón, J. P.; Caso, J. P.

    We present a preliminar photometric study of the globular cluster system (GCS), associated to the lenticular galaxy (S0) NGC 6861, which is located in a low density environment (d˜31.8 Mpc). It is based on GEMINI/GMOS images (GS-2010B-Q-2: PI Lilia P. Bassino) in the filters g', r', i' of three fields, one of them centered in the galaxy. We find a large number of GCs candidates and detect the presence of at least two sub-populations of GCs (``blue''/metal-poor and ``red''/metal-rich). The spatial distribution of ``red'' candidates presents a higher concentration toward the galaxy (associated to the bulge?), while the distribution of ``blue'' candidates is more homogeneus over the three fields (associated to the halo?). In the color-magnitud diagram, the ``blue'' GC candidates show a possible mass-luminosity relation, known as ``blue-tilt'', probably detected for the first time in a lenticular galaxy. FULL TEXT IN SPANISH

  11. Distribuciones Espectrales de Energía de las compañeras visibles en sistemas binarios que albergan agujeros negros de masas estelares

    NASA Astrophysics Data System (ADS)

    Cúneo, V. A.; Gómez, M. N.

    Stellar mass black holes are mainly detected in binary systems; where the compact object accretes material from its visible compa-nion. With the objective of characterizing visible companions; we analyse the Spectral Energy Distributions (SEDs) of a sample of these objects; selected from a galactic stellar black holes catalogue built by the authors. Using the VOSA SED Analyzer; we obtained; from several catalogues; the fluxes to construct the SEDs. A black body for a single star was adjusted for every observed SED. The excesses found between these distributions are attributed to the presence of the compact object. FULL TEXT IN SPANISH

  12. Investigacion del sistema ABS/PC a partir de material reciclado procedente del sector electrico y electronico. Caracterizacion y optimizacion de mezclas industriales

    NASA Astrophysics Data System (ADS)

    Balart Gimeno, Rafael

    In the last years, polymer blends have acquired great relevance due to the excellent performances that can be reached. Particularly, ABS/PC blends show a growing interest since they exhibit good thermal and mechanical performance. All these features make them useful for technical applications: electronics, automotive, house ware and office,...PC contributes to a good thermal and mechanical stability, while ABS contributes, fundamentally, to the improvement of processability and cost reduction. Considering the importance of these blends, it has been developed the possibility to recycle ABS and PC by blending systems, following the residue generation ratio (around 4:1 for ABS:PC). In this research, we have worked with polycarbonate coming from city lighting and a most common degree of ABS. Due to the nature and origin of recycled materials, it is important to know and to quantify the previous level of degradation of individual materials as well as the thermal behaviour of the blends to establish the possible interaction of the components. We have used calorimetric and spectrophotometric techniques to identify previous degradation and the presence of impurities in the recycled as well as the characterization of the blends. Thermogravimetric analysis has been used for kinetic study of degradation processes and thermal stability of ABS/PC system. We have also studied mechanical properties of ABS/PC system due to the partial miscibility of the system which involves a reduction on mechanical performance, particularly plastic properties such as impact strength while resistant properties show no important decrease. The small decrease on impact strength can be attributed to the degradation processes of butadiene present in the ABS and interphase interaction between partial miscible phases. The addition of PC improves thermal stability of the blend since the thermal resistance of the PC is higher than that of ABS. Mechanical properties stand with good equilibrium and the processability of blends is quite good. All this features contributes to a high viability of the blending process of ABS/PC from recycled materials.

  13. Código para imageamento indireto de estrelas em sistemas binarios: simulação de variações elipsoidais e do perfil das linhas

    NASA Astrophysics Data System (ADS)

    Souza, T. R.; Baptista, R.

    2003-08-01

    As estrelas secundárias em variáveis cataclí smicas (VCs) e binárias-x de baixa massa (BXBMs) são cruciais para o entendimento da origem, evolução e comportamento destas binárias interagentes. Elas são estrelas magneticamente ativas submetidas a condições ambientais extremas [e.g., estão muito próximas de uma fonte quente e irradiante; têm rotação extremamente rápida e forma distorcida; estão perdendo massa a taxas de 10-8-10-10 M¤/ano] que contribuem para que suas propriedades sejam distintas das de estrelas de mesma massa na seqüência principal. Por outro lado, o padrão de irradiação na face da secundária fornece informação sobre a geometria das estruturas de acréscimo em torno da estrela primária. Assim, a obtenção de imagens da superfície destas estrelas é de grande interesse astrofísico. A Tomografia Roche usa as variações no perfil das linhas de emissão/absorção da estrela secundária em função da fase orbital para mapear a distribuição de brilho em sua superfície. Neste trabalho apresentamos os resultados iniciais do desenvolvimento de um programa para o mapeamento da distribuição de brilho na superfí cie das estrelas secundárias em VCs e BXBMs com técnicas de astro-tomografia. Presentemente temos em operação um código que simula as variações no perfil das linhas em conseqüência de efeito Doppler resultante da combinação de rotação e translação de uma estrela em forma de lobo de Roche em torno do centro de massa da binária, em função da distribuição de brilho na superfície desta estrela. O código igualmente produz a curva de luz resultante das variações de aspecto da estrela em função da fase orbital (variações elipsoidais).

  14. Sistema de Transferencia de Archivos para Estudiantes Migrantes: Un Mejor Entendimiento para Padres. (Migrant Student Record Transfer System: A Better Understanding for Parents).

    ERIC Educational Resources Information Center

    Jaramillo, Senaida I.

    When migrant children are enrolled in the Migrant Education Program, they are also enrolled in the Migrant Student Record Transfer System (MSRTS), a national system which accumulates educational and health information for each child on a computer located in Little Rock, Arkansas. The system affords teachers the opportunity to review the records,…

  15. El humanismo y la educacion en diversos niveles del sistema educativo national (Humanism and Education at Different Levels of the National Education System).

    ERIC Educational Resources Information Center

    Consejo Nacional Tecnico de la Educacion (Mexico).

    This document is an English-language abstract (approximately 1,500 words) of six studies of the different levels of education and the humanistic content of the teaching program at each level. On the preschool level, it is stated that kindergarten education in Mexico attempts to put the small child in contact with the world that surrounds him.…

  16. Trazando el mapa genético de NGC 1316 a través de su sistema de cúmulos globulares

    NASA Astrophysics Data System (ADS)

    Sesto, L. A.; Faifer, F. R.; Forte, J. C.

    2015-08-01

    The giant early-type galaxy NGC 1316 (Fornax A) is an intermediate-age merger remnant (-- yrs), in which an unusual pattern of dust, formed by large filaments and dark structures, demands special attention. This galaxy belongs to Fornax, one of the closest and most studied galaxy clusters of the southern hemisphere. The dust structures pose an interesting challenge for photometry in the central regions. Based on the idea that Globular Clusters systems (GCS) constitute genuine tracers of the formation and evolution of galaxies that contain them, we present a multicolor photometric study of globular clusters candidates (GC) associated with NGC 1316. We performed the reduction and analysis of a mosaic of gri images obtained with the Gemini Multi-object Spectrograph (GMOS) camera, mounted on the Gemini South telescope. These GMOS data were combined with BVIgz photometry from the HST Advanced Camera for Surveys (ACS) as well as with published Washington photometry, and used to define a multicolor grid. This grid will be used to attempt to identify the properties of the different subpopulations of CG present in NGC 1316.

  17. Controllable synthesis of monodispersed silver nanoparticles as standards for quantitative assessment of their cytotoxicity.

    PubMed

    Li, Lun; Sun, Jie; Li, Xiaoran; Zhang, Yan; Wang, Zhaoxu; Wang, Chunren; Dai, Jianwu; Wang, Qiangbin

    2012-02-01

    Silver nanoparticles (Ag NPs) are appealing due to their excellent antibacterial/antivirus properties. At the meantime, the wide applications of Ag NPs as antibacterial/antivirus agents arise the concern of Ag NPs' toxicity. However, quantitative understanding of the cytotoxicity of Ag NPs is minimum since that the Ag NPs in current studies have wide size distributions, in which the size effect of Ag NPs on cytotoxicity was unable to be accurately evaluated. In this work, unprecedentedly monodispersed Ag NPs with sizes of 25, 35, 45, 60 and 70 nm were obtained, respectively, by using an optimized polyol method with poly(vinyl pyrrolidone) (PVP) as surfactant. It was found that the reaction temperature, reaction time, concentration of the surfactant and reactants are playing important roles in determining the size and size distribution of Ag NPs. With the monodispersed Ag NPs as standard samples, the size- and dose- dependent cytotoxicity of Ag NPs against Human lung fibroblast (HLF) cells was accurately accomplished in terms of cell viability, apoptosis and necrosis, reactive oxygen species, etc. We expect that the monodispersed Ag NPs will act as the standard samples for quantitatively characterizing the toxicity of Ag NPs in vitro and in vivo. PMID:22137123

  18. ADIPOQUINAS EN EL NIÑO SANO Y AFECTO DE OBESIDAD

    PubMed Central

    Martos-Moreno, G.A.; Kopchick, J.J.; Argente, y J.

    2015-01-01

    El incremento universal de la prevalencia de obesidad en niños y adolescentes durante las últimas décadas, junto con la evidencia creciente de que el establecimiento de obesidad en etapas precoces de la vida está asociado con un incremento de la prevalencia de comorbilidades y del riesgo de muerte prematura, con gran repercusión económica en los sistemas sanitarios de los países occidentales, ha impulsado la investigación en este área. Estos estudios han remarcado la importante actividad endocrina del tejido adiposo, ejercida por medio de la síntesis y secreción de un gran número de péptidos y citoquinas, denominados adipoquinas. En esta revisión se resume el estado actual de los conocimientos, así como los estudios más relevantes, en relación con la dinámica de secreción de las principales adipoquinas en niños, centrándose en el control de la homeostasis energética, regulación metabólica (fundamentalmente, metabolismo de los hidratos de carbono) e inflamación. Asímismo, se analizan las particularidades de la síntesis, secreción y acciones de las adipoquinas desde el nacimiento hasta la adolescencia, reseñando el efecto que, sobre ellas, ejerce la instauración de la obesidad. PMID:23228441

  19. Aplicación de la metodología Molecular de Orbitales de Defecto Cuántico (MQDO) al cálculo de intensidades vibrónicas y vidas medias de niveles vibracionales

    NASA Astrophysics Data System (ADS)

    María Velasco Sanz, Ana

    Desde que se formuló, en 1996, la metodología Molecular de Orbitales de Defecto Cuántico (MQDO) [1], se han obtenido datos de calidad relativos a intensidades de bandas electrónicas que implican estados Rydberg para una gran variedad de sistemas moleculares [2]. Animados por los buenos resultados obtenidos, recientemente hemos abordado el estudio de transiciones vibrónicas, es decir aquellas que ocurren entre estados vibracionales que pertenecen a distintos estados Rydberg electrónicos. Como prototipo adecuado para nuestros propósitos hemos elegido la molécula de NO, importante en la química de la atmósfera, y para la cual existen en la bibliografía datos experimentales de calidad suficiente para contrastar la validez de nuestros resultados. En concreto, hemos calculado las fuerzas de oscilador y coeficientes de Einstein para transiciones electrónicas y vibrónicas de las principales bandas del NO, al igual que vidas medias radiativas de niveles vibracionales de dicha molécula. Las propiedades estudiadas son esenciales para la comprensión de los aspectos teóricos de los procesos físicos básicos relativos a la dispersión electrónica en moléculas heteronucleares con capas abiertas. Además, valores fiables de probabilidades de transición moleculares tienen importantes aplicaciones en Astrofísica, en la modelización de procesos fotodinámicos moleculares, etc., al igual que para evaluar más profundamente la validez de nuestra metodología teórica.

  20. The origin of increased salinity in the Cambrian-Vendian aquifer system on the Kopli Peninsula, northern Estonia

    NASA Astrophysics Data System (ADS)

    Karro, Enn; Marandi, Andres; Vaikmäe, Rein

    Monitoring of the confined Cambrian-Vendian aquifer system utilised for industrial water supply at Kopli Peninsula in Tallinn over 24 years reveals remarkable changes in chemical composition of groundwater. A relatively fast 1.5 to 3.0-fold increase in TDS and in concentrations of major ions in ed groundwater is the consequence of heavy pumping. The main sources of dissolved load in Cambrian-Vendian groundwater are the leaching of host rock and the other geochemical processes that occur in the saturated zone. Underlying crystalline basement, which comprises saline groundwater in its upper weathered and fissured portion, and which is hydraulically connected with the overlying Cambrian-Vendian aquifer system, is the second important source of ions. The fractured basement and its clayey weathering crust host the Ca-Cl type groundwater, which is characterised by high TDS values (2-20 g/L). Intensive water ion accelerates the exchange of groundwaters and increases the area of influence of pumping. Chemical and isotopic studies of groundwater indicate an increasing contribution of old brackish water from the crystalline basement and rule out the potential implication of an intrusion of seawater into aquifer. L'origine de la salinité croissante dans le système aquifère du Cambrien-Vendien dans la péninsule de Kopli, nord de l'Estonie Le suivi à long terme du système aquifère captif du Cambrien-Vendien utilisé pour l'approvisionnement d'eaux industrielles dans la Péninsule de Kopli, nord de l'Estonie, révèle de remarquables changements dans la composition chimique des eaux souterraines. Une augmentation de facteur 1.5 à 3 de la TDS et des concentrations en ions majeurs dans l'eau souterraine est la conséquence de pompages intensifs. Les sources principales des charges dissoutes dans les eaux de l'aquifère du Cambrien-Vendien sont le lessivage des roches et d'autres phénomènes géochimiques ayant lieu dans la zone saturée. Le soubassement rocheux cristallin, qui renferme des eaux souterraines salines dans sa partie supérieure altérée et fissurée, et est hydrauliquement connecté avec l'aquifère supérieur du Cambrien-Vendien, est la deuxième importante source d'ions. Le soubassement fracturé et le matériel argileux de l'altération, renferme l'eau souterraine de type Ca-Cl, caractérisée par un haut TDS (2-20 g/l). A cause de la mobilisation intensive de l'eau les échanges d'eau souterraine est sont accélérés et la zone d'influence des pompages augmentent. Les études chimiques et isotopiques indiquent une contribution croissante du drainage des eaux du soubassement cristallin. L'intrusion d'eaux salées de la mer dans le système aquifère n'est pas un phénomène évident. El origen del incremento en salinidad en un sistema de acuíferos Cámbrico-Vendiano en la Península Kopli, norte de Estonie Monitoreo a largo plazo de un sistema de acuíferos confinados, de edad Cámbrico-Vendiano, que se utiliza como fuente de abastecimiento industrial en la Península Kopli, al norte de Estonie, revela cambios notables en la composición química del agua subterránea. Un incremento de 1.5 a 3 veces en TDS y en concentraciones de iones mayores en agua subterránea explotada ha sido ocasionado por bombeo fuerte. Las fuentes principales de carga disuelta en el agua subterránea Cámbrico-Vendiano son la lixiviación de la roca encajonante y los procesos geoquímicos que ocurren en la zona saturada. Basamento cristalino subyacente, que aloja agua subterránea salada en la parte superior intemperizada y fisurada, y está conectado hidráulicamente con el sistema acuífero Cámbrico-Vendiano sobreyacente, es la segunda fuente importante de iones. El basamento fracturado y su corteza de intemperismo arcillosa alojan agua subterránea de tipo Ca-Cl la cual se caracteriza por valores altos de TDS (2-20 g/l). Debido a extracción intensiva se ha acelerado el intercambio de agua subterránea y se ha incrementado el área de influencia del bombeo. Los estudios químicos e isotópicos de agua subterránea indican una contribución creciente por filtración derivada del basamento cristalino. Es evidente una intrusión de agua salada hacia el sistema de acuíferos con implicaciones subsecuentes para la calidad del agua.

  1. Deep PDF parsing to extract features for detecting embedded malware.

    SciTech Connect

    Munson, Miles Arthur; Cross, Jesse S.

    2011-09-01

    The number of PDF files with embedded malicious code has risen significantly in the past few years. This is due to the portability of the file format, the ways Adobe Reader recovers from corrupt PDF files, the addition of many multimedia and scripting extensions to the file format, and many format properties the malware author may use to disguise the presence of malware. Current research focuses on executable, MS Office, and HTML formats. In this paper, several features and properties of PDF Files are identified. Features are extracted using an instrumented open source PDF viewer. The feature descriptions of benign and malicious PDFs can be used to construct a machine learning model for detecting possible malware in future PDF files. The detection rate of PDF malware by current antivirus software is very low. A PDF file is easy to edit and manipulate because it is a text format, providing a low barrier to malware authors. Analyzing PDF files for malware is nonetheless difficult because of (a) the complexity of the formatting language, (b) the parsing idiosyncrasies in Adobe Reader, and (c) undocumented correction techniques employed in Adobe Reader. In May 2011, Esparza demonstrated that PDF malware could be hidden from 42 of 43 antivirus packages by combining multiple obfuscation techniques [4]. One reason current antivirus software fails is the ease of varying byte sequences in PDF malware, thereby rendering conventional signature-based virus detection useless. The compression and encryption functions produce sequences of bytes that are each functions of multiple input bytes. As a result, padding the malware payload with some whitespace before compression/encryption can change many of the bytes in the final payload. In this study we analyzed a corpus of 2591 benign and 87 malicious PDF files. While this corpus is admittedly small, it allowed us to test a system for collecting indicators of embedded PDF malware. We will call these indicators features throughout the rest of this report. The features are extracted using an instrumented PDF viewer, and are the inputs to a prediction model that scores the likelihood of a PDF file containing malware. The prediction model is constructed from a sample of labeled data by a machine learning algorithm (specifically, decision tree ensemble learning). Preliminary experiments show that the model is able to detect half of the PDF malware in the corpus with zero false alarms. We conclude the report with suggestions for extending this work to detect a greater variety of PDF malware.

  2. Como Lo Hago Yo: Mielomeningocele En Bolivia

    PubMed Central

    Dabdoub, Carlos F.; Dabdoub, Carlos B.; Villavicencio, Ramiro; Quevedo, Germán

    2014-01-01

    Introducción: Las malformaciones del tubo neural (MTN) representan la segunda causa más frecuente de anomalías congénitas, luego de las cardiopatías. En este grupo se destaca el mielomeningocele (MMC) por su mayor incidencia, y por ser la más incapacitante y la más compleja entre todas las demás malformaciones del sistema nervioso c`entral (SNC). En Bolivia, como en muchos países de Sudamérica, los bajos niveles socio-culturales y la debilidad en el sistema sanitario, hacen que su incidencia y su morbilidad, sean mayores que en las naciones más desarrolladas. Material y Métodos: Se realizó un estudio retrospectivo y descriptivo de 70 casos de MMC, atendidos por un equipo multidisciplinario en el Hospital Universitario Japonés (HUJ) de Santa Cruz de la Sierra, entre 2008-2011. De ellos, 60 fueron intervenidos quirúrgicamente. Resultados: Se realizaron controles prenatales sólo en 27 mujeres (38.6%), diagnosticándose una disrafia espinal en apenas dos casos (7.4%). La edad de ingreso del MMC en su mayoría fue después de las 24 horas (65.6%), predominando su localización en la región lumbosacra (64.3%). De ellos, 67.2% eran abiertos, presentando un 32.9% un daño neurológico motor parcial mientras que 47.1% tenían paraplejia por debajo de la lesión. De los 70 casos, tres (4.3%) no fueron intervenidos, por presentar defectos congénitos severos o estado general grave. Las principales complicaciones posoperatorias inmediatas fueron: dehiscencia de sutura y/o infección de la herida (16.6%), fístula de líquido cefalorraquídeo (LCR) (10%) e infección del SNC (11.7%). La mortalidad general y postoperatoria fue de 7.1% y 3.3%, respectivamente. Al mes de vida presentaban hidrocefalia un 80% de los pacientes operados, colocándose una derivación ventriculoperitoneal (DVP) de presión media. De 9 pacientes que tuvieron un acompanamiento de dos o más años, seis presentaron una médula anclada, que fueron intervenidas quirúrgicamente. Conclusión: En esta serie, el diagnóstico prenatal del MMC fue ocasional y la derivación al HUJ de los recién nacidos con esta malformación fue generalmente tardía. No hubo predominio de género y la mayoría de los casos presentaron sus lesiones en la región lumbar y lumbosacra. La mortalidad general y postoperatoria fue similar a la reportada en la literatura. Pocos enfermos realizaron controles posteriores al alta hospitalaria. Igual que otros países de Sudamérica, las falencias en el sistema público de salud y el nivel sociocultural, son factores determinantes para un mal pronóstico en estos niños. Por sus múltiples complicaciones, el MMC requiere de una especial atención gubernamental, sobre todo de carácter preventivo mediante el uso de ácido fólico en mujeres fértiles, como también de un equipo profesional multidisciplinario, a fin de realizar un tratamiento adecuado y oportuno. Al mismo tiempo, trabajos multicéntricos en hospitales de América Latina, ayudarán al mejor manejo de estos pacientes. PMID:24791220

  3. Analysis and Synthesis of Leaky-Wave Devices in Planar Technology

    NASA Astrophysics Data System (ADS)

    Martinez Ros, Alejandro Javier

    The work developed along this doctoral thesis has been focused on the analysis and synthesis of microwave devices in planar technology. In particular, several types of devices based on the radiation mechanism of leaky waves have been studied. Typically, the radiation properties in leaky-wave devices are determined by the complex propagation constant of the leaky mode, wherein the phase constant is responsible for the pointing angle and the leakage rate for the intensity of the radiated fields. In this manner, by controlling both amplitude and phase of the leaky mode, an effective control over the device's radiation diagram can be obtained. Moreover, with the purpose of efficiently obtaining the leaky mode's radiation properties as function of the main geometrical parameters of the structure, several modal tools based on the transverse resonance analysis of the structure have been performed. In order to demonstrate this simultaneous control over the complex propagation constant in planar technology, several types of leaky-wave devices, including antennas (LWAs), multiplexors and near-field focusing systems, have been designed and manufactured in the technology of substrate integrated waveguide (SIW). This recently proposed technology, allows the design of devices based on classical waveguide technology with standard manufacturing techniques used for printed circuit board (PCB) designs. In this way, most of the parts that form a communication system can be integrated into a single substrate, thus reducing its cost and providing a more robust and compact device, which has less losses compared to other planar technologies such as the microstrip. El trabajo llevado a cabo durante la realizacion de esta tesis doctoral, se ha centrado en el analisis y sintesis de dispositivos de microondas en tecnologia planar. En concreto, se han estudiado diferentes tipos de dispositivos basados en radiacion por ondas de fuga "leaky waves", en los cuales las propiedades de radiacion estan determinadas por la constante de fase del modo "leaky" que es el que determina el angulo de apuntamiento y por la tasa de radiacion que es la que determina la intensidad de los campos radiados. De esta manera, controlando en amplitud y fase el modo "leaky" se puede obtener un control efectivo sobre el diagrama de radiacion del dispositivo. Ademas, con el objetivo de poder obtener de una manera mas eficiente las caracteristicas de propagacion de los modos de fuga "leaky" en funcion de los principales parametros geometricos de la estructura, se han desarrollado diversas herramientas de analisis modal basadas en la tecnica de resonancia transversa de la estructura. La capacidad para obtener un control simultaneo de la constante de propagacion compleja del modo "leaky", ha sido demostrada mediante el diseno y fabricacion de varios tipos de antena "leaky wave" (LWA) y de otros dispositivos como multiplexores y sistemas de enfoque en campo cercano. Para ello, se ha utilizado la tecnologia planar de guia de onda integrada en sustrato (susbstrate integrated waveguide, SIW). Esta recientemente desarrollada tecnologia, permite disenar dispositivos de microondas basados en tecnologia clasica de guia de ondas con sistemas de fabricacion estandar usados en tecnologia de circuitos impresos (printed circuit board, PCB). De esta forma, se pueden integrar en un mismo sustrato muchas de las diferentes partes que forman un sistema de comunicaciones, mejorando asi su robustez y compactibilidad, ademas de reducir el coste y de contar con menores perdidas que otras tecnologias planares como la microstrip.

  4. The Unknown Computer Viruses Detection Based on Similarity

    NASA Astrophysics Data System (ADS)

    Liu, Zhongda; Nakaya, Naoshi; Koui, Yuuji

    New computer viruses are continually being generated and they cause damage all over the world. In general, current anti-virus software detects viruses by matching a pattern based on the signature; thus, unknown viruses without any signature cannot be detected. Although there are some static analysis technologies that do not depend on signatures, virus writers often use code obfuscation techniques, which make it difficult to execute a code analysis. As is generally known, unknown viruses and known viruses share a common feature. In this paper we propose a new static analysis technology that can circumvent code obfuscation to extract the common feature and detect unknown viruses based on similarity. The results of evaluation experiments demonstrated that this technique is able to detect unknown viruses without false positives.

  5. Global dynamics of a novel multi-group model for computer worms

    NASA Astrophysics Data System (ADS)

    Gong, Yong-Wang; Song, Yu-Rong; Jiang, Guo-Ping

    2013-04-01

    In this paper, we study worm dynamics in computer networks composed of many autonomous systems. A novel multi-group SIQR (susceptible-infected-quarantined-removed) model is proposed for computer worms by explicitly considering anti-virus measures and the network infrastructure. Then, the basic reproduction number of worm R0 is derived and the global dynamics of the model are established. It is shown that if R0 is less than or equal to 1, the disease-free equilibrium is globally asymptotically stable and the worm dies out eventually, whereas, if R0 is greater than 1, one unique endemic equilibrium exists and it is globally asymptotically stable, thus the worm persists in the network. Finally, numerical simulations are given to illustrate the theoretical results.

  6. The effect of infected external computers on the spread of viruses: A compartment modeling study

    NASA Astrophysics Data System (ADS)

    Yang, Lu-Xing; Yang, Xiaofan

    2013-12-01

    Inevitably, there exist infected computers outside of the Internet. This paper aims to understand how infected external computers affect the spread of computer viruses. For that purpose, a new virus-antivirus spreading model, which takes into account the effect of infected/immune external computers, is established. A systematic study shows that, unlike most previous models, the proposed model admits no virus-free equilibrium and admits a globally asymptotically stable viral equilibrium. This result implies that it would be practically impossible to eradicate viruses on the Internet. As a result, inhibiting the virus prevalence to below an acceptable level would be the next best thing. A theoretical study reveals the effect of different parameters on the steady virus prevalence. On this basis, a number of suggestions are made so as to contain virus spreading.

  7. Structure-activity relationship of N-benzenesulfonyl matrinic acid derivatives as a novel class of coxsackievirus B3 inhibitors.

    PubMed

    Wang, Sheng-Gang; Kong, Lan-Ying; Li, Ying-Hong; Cheng, Xin-Yue; Su, Feng; Tang, Sheng; Bi, Chong-Wen; Jiang, Jian-Dong; Li, Yu-Huan; Song, Dan-Qing

    2015-09-01

    A novel series of N-benzenesulfonyl matrinic amine/amide and matrinic methyl ether analogues were designed, synthesized and evaluated for their in vitro anti-coxsackievirus B3 (CVB3) activities. The structure-activity relationship (SAR) studies revealed that introduction of a suitable amide substituent on position 4' could greatly enhance the antivirus potency. Compared to the lead compounds, the newly synthesized matrinic amide derivatives 21c-d and 21j exhibited stronger anti-CVB3 activities with lower micromolar IC50 from 2.5 ?M to 2.7 ?M, and better therapeutic properties with improved selectivity index (SI) from 63 to 67. The SAR results provided powerful information for further strategic optimization, and these top compounds were selected for the next evaluation as novel enterovirus inhibitors. PMID:26112440

  8. Design of Cyber Attack Precursor Symptom Detection Algorithm through System Base Behavior Analysis and Memory Monitoring

    NASA Astrophysics Data System (ADS)

    Jung, Sungmo; Kim, Jong Hyun; Cagalaban, Giovanni; Lim, Ji-Hoon; Kim, Seoksoo

    More recently, botnet-based cyber attacks, including a spam mail or a DDos attack, have sharply increased, which poses a fatal threat to Internet services. At present, antivirus businesses make it top priority to detect malicious code in the shortest time possible (Lv.2), based on the graph showing a relation between spread of malicious code and time, which allows them to detect after malicious code occurs. Despite early detection, however, it is not possible to prevent malicious code from occurring. Thus, we have developed an algorithm that can detect precursor symptoms at Lv.1 to prevent a cyber attack using an evasion method of 'an executing environment aware attack' by analyzing system behaviors and monitoring memory.

  9. [Review of bioactivities of natural cycloartane triterpenoids].

    PubMed

    Tian, Ze; Xiao, Pei-gen; Wen, Jie; Huang, Feng; Yang, Meng-su; Chen, Shi-lin

    2006-04-01

    Cycloartane triterpenoids, which exist widely in nature, are mainly distributed in Astragalus (Leguminosae) species, Trib. Cimicifuga (Ranunculaceae) and Thalictrium (Ranunculaceae) species and possess various bioactivities. Along with the development of isolation techniques of phytochemistry, more and more this kind of compounds are isolated and identified. However, bioactivity researches on the compounds are relatively lagged behind. Most researches are still in screening level, deficient in mechanism elucidation, short of action proven in vivo and SAR analysis. The author summarized the bioactivity of this kind of compounds from all aspects: anti-tumor, anti-virus, antibacterial, anti-inflammation, immune-regulatory, cardiovascular system, hepatic protection and so forth. This will be benefit for the further research and development of the compounds. PMID:16830816

  10. Design, Synthesis and Antiviral Activity Studies of Schizonepetin Derivatives

    PubMed Central

    Bao, Beihua; Meng, Zheng; Li, Nianguang; Meng, Zhengjie; Zhang, Li; Cao, Yudan; Yao, Weifeng; Shan, Mingqiu; Ding, Anwei

    2013-01-01

    A series of schizonepetin derivatives have been designed and synthesized in order to obtain potent antivirus agents. The antiviral activity against HSV-1 and influenza virus H3N2 as well as the cytotoxicity of these derivatives was evaluated by using cytopathic effect (CPE) inhibition assay in vitro. Compounds M2, M4, M5 and M34 showed higher inhibitory activity against HSV-1 virus with the TC50 values being in micromole. Compounds M28, M33, and M35 showed higher inhibitory activity against influenza virus H3N2 with their TC50 values being 96.4, 71.0 and 75.4 μM, respectively. Preliminary biological activity evaluation indicated that the anti-H3N2 and anti-HSV-1 activities improved obviously through the introduction of halogen into the structure of schizonepetin. PMID:23965980

  11. A Study on Architecture of Malicious Code Blocking Scheme with White List in Smartphone Environment

    NASA Astrophysics Data System (ADS)

    Lee, Kijeong; Tolentino, Randy S.; Park, Gil-Cheol; Kim, Yong-Tae

    Recently, the interest and demands for mobile communications are growing so fast because of the increasing prevalence of smartphones around the world. In addition, the existing feature phones were replaced by smartphones and it has widely improved while using the explosive growth of Internet users using smartphones, e-commerce enabled Internet banking transactions and the importance of protecting personal information. Therefore, the development of smartphones antivirus products was developed and launched in order to prevent malicious code or virus infection. In this paper, we proposed a new scheme to protect the smartphone from malicious codes and malicious applications that are element of security threats in mobile environment and to prevent information leakage from malicious code infection. The proposed scheme is based on the white list smartphone application which only allows installing authorized applications and to prevent the installation of malicious and untrusted mobile applications which can possibly infect the applications and programs of smartphones.

  12. Access Control of Web and Java Based Applications

    NASA Technical Reports Server (NTRS)

    Tso, Kam S.; Pajevski, Michael J.; Johnson, Bryan

    2011-01-01

    Cyber security has gained national and international attention as a result of near continuous headlines from financial institutions, retail stores, government offices and universities reporting compromised systems and stolen data. Concerns continue to rise as threats of service interruption, and spreading of viruses become ever more prevalent and serious. Controlling access to application layer resources is a critical component in a layered security solution that includes encryption, firewalls, virtual private networks, antivirus, and intrusion detection. In this paper we discuss the development of an application-level access control solution, based on an open-source access manager augmented with custom software components, to provide protection to both Web-based and Java-based client and server applications.

  13. Identification of the Fluvirucin B2 (Sch 38518) Biosynthetic Gene Cluster from Actinomadura fulva subsp. indica ATCC 53714: substrate Specificity of the β-Amino Acid Selective Adenylating Enzyme FlvN.

    PubMed

    Miyanaga, Akimasa; Hayakawa, Yuki; Numakura, Mario; Hashimoto, Junko; Teruya, Kuniko; Hirano, Takashi; Shin-Ya, Kazuo; Kudo, Fumitaka; Eguchi, Tadashi

    2016-05-01

    Fluvirucins are 14-membered macrolactam polyketides that show antifungal and antivirus activities. Fluvirucins have the β-alanine starter unit at their polyketide skeletons. To understand the construction mechanism of the β-alanine moiety in fluvirucin biosyntheses, we have identified the biosynthetic cluster of fluvirucin B2 produced from Actinomadura fulva subsp. indica ATCC 53714. The identified gene cluster contains three polyketide synthases, four characteristic β-amino acid-carrying enzymes, one decarboxylase, and one amidohydrolase. We next investigated the activity of the adenylation enzyme FlvN, which is a key enzyme for the selective incorporation of a β-amino acid substrate. FlvN showed strong preference for l-aspartate over other amino acids such as β-alanine. Based on these results, we propose a biosynthetic pathway for fluvirucin B2. PMID:26818633

  14. A study of malware detection on smart mobile devices

    NASA Astrophysics Data System (ADS)

    Yu, Wei; Zhang, Hanlin; Xu, Guobin

    2013-05-01

    The growing in use of smart mobile devices for everyday applications has stimulated the spread of mobile malware, especially on popular mobile platforms. As a consequence, malware detection becomes ever more critical in sustaining the mobile market and providing a better user experience. In this paper, we review the existing malware and detection schemes. Using real-world malware samples with known signatures, we evaluate four popular commercial anti-virus tools and our data shows that these tools can achieve high detection accuracy. To deal with the new malware with unknown signatures, we study the anomaly based detection using decision tree algorithm. We evaluate the effectiveness of our detection scheme using malware and legitimate software samples. Our data shows that the detection scheme using decision tree can achieve a detection rate up to 90% and a false positive rate as low as 10%.

  15. Studying classical swine fever virus: making the best of a bad virus.

    PubMed

    Ji, Wei; Guo, Zhen; Ding, Nai-Zheng; He, Cheng-Qiang

    2015-02-01

    Classical swine fever (CSF) is a highly contagious and often fatal disease that affects domestic pigs and wild boars. Outbreak of CSF can cause heavy economic losses to the pig industry. The strategies to prevent, control and eradicate CSF disease are based on containing the disease through a systematic prophylactic vaccination policy and a non-vaccination stamping-out policy. The quest for prevention, control and eradication of CSF has moved research forward in academia and industry, and has produced noticeable advances in understanding fundamental aspects of the virus replication mechanisms, virulence, and led to the development of new vaccines. In this review we summarize recent progress in CSFV epidemiology, molecular features of the genome and proteome, the molecular basis of virulence, and the development of anti-virus technologies. PMID:25510481

  16. Microbial transformation of curcumol by Aspergillus niger.

    PubMed

    Chen, Li-Xia; Zhang, Hui; Zhao, Qian; Yin, Shi-Yu; Zhang, Zhong; Li, Tian-Xian; Qiu, Feng

    2013-02-01

    Curcumol is a representative index component for the quality control of the essential oil of Curcuma wenyujin Y.H. Chen et C. Ling, an antivirus and anticancer drug in China. Microbial transformation of curcumol (1) by Aspergillus niger AS 3.739 yielded two products. Their structures were elucidated as 3alpha-hydroxycurcumol (2) and 3alpha-(4'-methoxy-succinyloxy)-curcumol (3) by extensive spectroscopic methods including 2D-NMR and HRESI-MS. Among them, 3 is a new compound. Esterification of the substrate with succinic acid is a novel reaction in the field of microbial transformation of natural products. Compound 2, the major transformation product of 1, was a high regio- and stereo-specific hydroxylation product and showed significant antiviral effects. PMID:23513713

  17. Interaction of nanodiamonds materials with influenza viruses

    NASA Astrophysics Data System (ADS)

    Ivanova, V. T.; Ivanova, M. V.; Spitsyn, B. V.; Garina, K. O.; Trushakova, S. V.; Manykin, A. A.; Korzhenevsky, A. P.; Burseva, E. I.

    2012-02-01

    The perspectives of the application of modern materials contained nanodiamonds (ND) are considered in this study. The interaction between detonation paniculate ND, soot and influenza A and B viruses, fragments of cDNA were analyzed at the normal conditions. It was shown that these sorbents can interact with the following viruses: reference epidemic strains of influenza A(H1N1), A(H1N1)v, A(H3N2) and B viruses circulated in the word in 2000-2010. The allantoises, concentrated viruses, cDNA can be absorbed by ND sorbents and getting removed from water solutions within 20 min. ND sorbents can be used for the preparation of antivirus filters for water solution and for future diagnostic systems in virology.

  18. [Clinical trials and intensive therapy of the swine flu (H1N1)].

    PubMed

    Nakashidze, I M; Tsintsadze, N G; Potskhishvili, Sh N; Dzhibladze, K M

    2012-01-01

    During the recent years there's a high index of the swine flu А (H1N1) disease in the whole world. In Georgia it began to spread at the end of Autumn 2009. The aim of our study was to define clinical trials of the swine flu (H1N1) in patients of Republic Clinical Hospital in Batumi from 2009 to 2011 and to generalize the methods of treatment. In the hospital there were 94 patients suffering from the swine flu (H1N1) disease, 20 of which due to their critical situation of the disease were treated in the department of the intensive therapy. We studied case histories of 20 patients, who were undergoing treatment in the department of the intensive therapy by the generally acknowledged programme of study and monitoring due to their hard disease. Among these 20 patients 10 were women and 10 men. 10 patients died. The programme of intensive treatment consisted of infusive-transfusive therapy by the negative water balance, antivirus treatment (Tamiflu/Relenza), de-escalation antibiotic therapy, mechanic ventilation of lungs, aerosol therapy, plus symptom treatment. In 2011 there were fewer cases of the swine flu and the death rate compared to the earlier years. In 2011 of 25 patients only one patient died, but in 2009-2010 of 69 patients 7 patients died), which was conditioned by immunity development. The most frequently used regime of lung mechanic ventilation was BIPAR. In the first days antibiotic therapy is not defining. It is necessary to find more effective method of antivirus treatment. PMID:22392781

  19. Baculoviruses Modulate a Proapoptotic DNA Damage Response To Promote Virus Multiplication

    PubMed Central

    Mitchell, Jonathan K.

    2012-01-01

    The baculovirus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) initiates apoptosis in diverse insects through events triggered by virus DNA (vDNA) replication. To define the proapoptotic pathway and its role in antivirus defense, we investigated the link between the host's DNA damage response (DDR) and apoptosis. We report here that AcMNPV elicits a DDR in the model insect Drosophila melanogaster. Replication of vDNA activated DDR kinases, as evidenced by ATM-driven phosphorylation of the Drosophila histone H2AX homolog (H2Av), a critical regulator of the DDR. Ablation or inhibition of ATM repressed H2Av phosphorylation and blocked virus-induced apoptosis. The DDR kinase inhibitors caffeine and KU55933 also prevented virus-induced apoptosis in cells derived from the permissive AcMNPV host, Spodoptera frugiperda. This block occurred at a step upstream of virus-mediated depletion of the cellular inhibitor-of-apoptosis protein, an event that initiates apoptosis in Spodoptera and Drosophila. Thus, the DDR is a conserved, proapoptotic response to baculovirus infection. DDR inhibition also repressed vDNA replication and reduced virus yields 100,000-fold, demonstrating that the DDR contributes to virus production, despite its recognized antivirus role. In contrast to virus-induced phosphorylation of Drosophila H2Av, AcMNPV blocked phosphorylation of the Spodoptera H2AX homolog (SfH2AX). Remarkably, AcMNPV also suppressed SfH2AX phosphorylation following pharmacologically induced DNA damage. These findings indicate that AcMNPV alters canonical DDR signaling in permissive cells. We conclude that AcMNPV triggers a proapoptotic DDR that is subsequently modified, presumably to stimulate vDNA replication. Thus, manipulation of the DDR to facilitate multiplication is an evolutionarily conserved strategy among DNA viruses of insects and mammals. PMID:23035220

  20. Lack of security of networked medical equipment in radiology.

    PubMed

    Moses, Vinu; Korah, Ipeson

    2015-02-01

    OBJECTIVE. There are few articles in the literature describing the security and safety aspects of networked medical equipment in radiology departments. Most radiologists are unaware of the security issues. We review the security of the networked medical equipment of a typical radiology department. MATERIALS AND METHODS. All networked medical equipment in a radiology department was scanned for vulnerabilities with a port scanner and a network vulnerability scanner, and the vulnerabilities were classified using the Common Vulnerability Scoring System. A network sniffer was used to capture and analyze traffic on the radiology network for exposure of confidential patient data. We reviewed the use of antivirus software and firewalls on the networked medical equipment. USB ports and CD and DVD drives in the networked medical equipment were tested to see whether they allowed unauthorized access. Implementation of the virtual private network (VPN) that vendors use to access the radiology network was reviewed. RESULTS. Most of the networked medical equipment in our radiology department used vulnerable software with open ports and services. Of the 144 items scanned, 64 (44%) had at least one critical vulnerability, and 119 (83%) had at least one high-risk vulnerability. Most equipment did not encrypt traffic and allowed capture of confidential patient data. Of the 144 items scanned, two (1%) used antivirus software and three (2%) had a firewall enabled. The USB ports were not secure on 49 of the 58 (84%) items with USB ports, and the CD or DVD drive was not secure on 17 of the 31 (55%) items with a CD or DVD drive. One of three vendors had an insecure implementation of VPN access. CONCLUSION. Radiologists and the medical industry need to urgently review and rectify the security issues in existing networked medical equipment. We hope that the results of our study and this article also raise awareness among radiologists about the security issues of networked medical equipment. PMID:25615757

  1. Lentivirus-mediated expression of MxA in chicken spermatogonial stem cells.

    PubMed

    Liu, L; He, P; Cai, K; Zhang, Y; Li, J; Cao, F; Ding, Z; Zhang, N

    2010-10-01

    The aim of this study was to construct a lentivirus vector that carries the human myxovirus-resistant A (MxA) anti-virus gene for efficiently infecting rooster spermatogonial stem cells (SSCs). A lentiviral vector carrying the enhanced green fluorescent protein (EGFP) and MxA fusion gene (EGFP-MxA) was constructed using TOPO technology in this study. Enhanced green fluorescent protein-MxA was inserted in the right orientation as determined by restriction enzyme digest. No gene recombination in the vector occurred. After infecting 293FT cells, EGFP-MxA fusion protein was expressed as granular green fluorescence characteristic of EGFP-MxA expression, suggesting that the TOPO expression vector was properly constructed and the fusion protein expressed correctly. The EGFP-MxA recombinant lentivirus was packaged by cotransfecting 293FT cells with EGFP-MxA and the packaging plasmids. We also purified SSCs from testicle tissues from 25-day-old roosters for infection with the EGFP-MxA recombinant virus. After infecting rooster SSCs with the recombinant virus for 72 h, EGFP-MxA expression was detected by EGFP expression. Enhanced green fluorescent protein-MxA expression in SSCs was further confirmed at the transcription level by RT-PCR and at the protein level by immunocytochemistry. Staining with Hoechst 33342 showed that infected SSCs differed from the sertoli cells. Similar to stem cells, SSCs were positive for alkaline phosphoric acid enzyme and for stage-specific embryonic antigen-1 stem cell factor. The results demonstrated that the recombinant virus made in our study can infect rooster SSCs efficiently to express the anti-virus protein MxA, establishing the basis of transferring MxA into SSCs to obtain virus-resistant, genetically-modified roosters. PMID:20412511

  2. Memorias Conferencia Internacional IEEE Mexico 1971, Sobre Sistemas, Redes Y Computadoras. Volumen I and Volumen II. (Proceedings of International Conference of IEEE Concerning Systems, Networks, and Computers. Volume I and Volume II.

    ERIC Educational Resources Information Center

    Concheiro, A. Alonso, Ed.; And Others

    The following papers in English from this international conference may be of particular interest to those in the field of education. T. Nakahara, A. Tsukamota, and M. Matsumoto describe a computer-aided design technique for an economical urban cable television system. W. D. Wasson and R. K. Chitkara outline a recognition scheme based on analysis…

  3. Metric System Resource Units = Unidades de Trabajo del Sistema Metrico Decimal. K-12. Project C.A.M.B.I.O., Changing Attitudes towards Metrics for Bilingual Instruction & Operations.

    ERIC Educational Resources Information Center

    Pulido, Josefina; Almendares, Simon

    Four resource units are included in this document. For each, general objectives on knowledge and concepts, skills, and attitudes are given; content is outlined; and some suggestions for initiating the unit are listed. The first unit, on measuring length, provides six lesson plans, to teach about the meter, the smaller units of the meter, units…

  4. Pautas para Organizar Una Actividad de Capacitacion: Un Seminario-Taller para el Desarrollo de Personal de Direccion de Sistemas Educativos (Guidelines to Organize a Training Activity: A Workshop for Management Development of Educational Systems).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    Often personnel performing managerial functions within educational systems are educators with almost no training in management. This paper presents ideas on how to organize a training activity intended to develop management knowledge and skills among educational systems officials and to implement an organizational self-study on management…

  5. La Capacitacion de Docentes Como Prioridad de los Sistemas Educativos de America Latino y al Caribe (In-Service Teacher Training as a Priority of Latin American and Caribbean Educational Systems).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    Whenever top-level officials in Latin American and Caribbean educational systems are approached, the topic of inservice teacher training is presented as a major priority. This paper outlines some ideas about the subject of inservice teacher training as a priority of educational systems in Latin American and Caribbean countries. The most frequent…

  6. "Buddy System": A Pedagogical Innovation to Promote Online Interaction (Sistema de amigos: una innovación pedagógica para fomentar la interacción en línea)

    ERIC Educational Resources Information Center

    Espitia Cruz, Martha Isabel; Kwinta, Anna

    2013-01-01

    Recent technological development has created new pedagogical practices in the EFL classroom to maximize the time for students to use the language by considering online tools. Whilst working in a pedagogical context with new technologies, some educators were concerned with how online interaction in EFL content-based classes could be effectively…

  7. Self-Image Development: A Chicano Enfasis. Self-Programmed Counseling and Self-Programmed Control. Instructor's Guide = Desarrollo de la Imagen Propia: Enfasis en el Chicano. Sistema de Consejo y Control Auto-Programado. Manuel del Profesor.

    ERIC Educational Resources Information Center

    Mireles, S. Raymond

    Self-Programmed Counseling, the instructor's guidance, and Self-Programmed Control (SPC), the student's response, was initially developed by Title III Project USTED (United Students and Teachers for Educational Development) for Mexican American students on academic probation to use on a non-credit, special group counseling basis. As part of a…

  8. Investigacion educativa. El sistema escolar en sus diferentes niveles, factores que favorecen o frenan su eficacia y medidas de superacion (Educational Research. The Educational System at Different Levels; Factors Promoting or Hindering Its Efficiency; Possible Improvements.

    ERIC Educational Resources Information Center

    Jimenez Lozano, Blanca; And Others

    This document is an English-language abstract (Approximately 1,500 words) of a study on educational research in Mexico. Chapter one discusses the importance of educational research, in terms of its role both in scientific and technical development; it should use scientific methods so that it will have solid foundations. Chapter two is a survey of…

  9. Edades y metalicidades de cinco cúmulos estelares proyectados en dirección a la Nube Menor de Magallanes: implicaciones sobre los procesos de formación y evolución de estos sistemas

    NASA Astrophysics Data System (ADS)

    Piatti, A. E.; Santos, J. F. C.; Clariá, J. J.; Bica, E.; Sarajedini, A.; Geisler, D.

    Washington photometry of the 5 star clusters Lindsay 32, Lindsay 38, Kron 28, Kron 44 and Lindsay 116 and their surrounding fields located towards the Small Magellanic Cloud (SMC) is presented for the first time. From the color-magnitude diagrams, cleaned from field stars contamination, the cluster and SMC field reddenings, ages and metallicities are determined. The ages - derived from the difference in the T1 magnitude betweem the giant clump and the Main Sequence turnoff point - vary between 2 and 6 Gyr, and the metallicities ([Fe/H]) between -1.65 and -1.10. Lindsay 116 is located closer to the Large Magellanic Cloud (LMC) than to the SMC and its fundamental parameters suggests a higher probability of belonging to the LMC. The results obtained in this work, combined with previous estimates of age and metallicity for other seven clusters, allow us to draw the following conclusions: (1) There does not exist an age-position relation in the SMC, but a age-metallicity one. (2) The chemical enrichment in the SMC has been very efficient during the last 5 Gyr. (3) The SMC clusters formation and evolution can be better represented by a bursting star formation process than by a continuum star formation mechanism.

  10. Self-Image Development: A Chicano Enfasis. Self-Programmed Counseling and Self-Programmed Control. Instructor's Guide = Desarrollo de la Imagen Propia: Enfasis en el Chicano. Sistema de Consejo y Control Auto-Programado. Manuel del Profesor.

    ERIC Educational Resources Information Center

    Mireles, S. Raymond

    Self-Programmed Counseling, the instructor's guidance, and Self-Programmed Control (SPC), the student's response, was initially developed by Title III Project USTED (United Students and Teachers for Educational Development) for Mexican American students on academic probation to use on a non-credit, special group counseling basis. As part of a…

  11. Primera Reunion de la Comision Nacional de Analisis y Evaluacion del Sistema Educativo: Informe Final (The First Meeting of the National Committee for Analysis and Evaluation of the Educational System: Final Report).

    ERIC Educational Resources Information Center

    Ministerio de Cultura y Educacion, Buenos Aires (Argentina). Centro National de Documentacion e Informacion Educativa.

    This document contains the legislation creating the National Committee for Analysis and Evaluation of the Educational System and the final report of that committee's first meeting. The report deals with each level from elementary to higher education. For each level it describes and considers curriculum, school buildings, human resources, current…

  12. Metric System Resource Units = Unidades de Trabajo del Sistema Metrico Decimal. K-12. Project C.A.M.B.I.O., Changing Attitudes towards Metrics for Bilingual Instruction & Operations.

    ERIC Educational Resources Information Center

    Pulido, Josefina; Almendares, Simon

    Four resource units are included in this document. For each, general objectives on knowledge and concepts, skills, and attitudes are given; content is outlined; and some suggestions for initiating the unit are listed. The first unit, on measuring length, provides six lesson plans, to teach about the meter, the smaller units of the meter, units…

  13. CURRENT PEACH PRODUCTION PRACTICES INCLUDING NEX TRAINING SYSTEMS IN THE SOUTHEASTERN U.S. PRACTICAS ACTUALES DE PRODUCCION DE DURAZNO, INCLUYENDO SISTEMAS DE FORMACION EN EL SURESTE DE LOS ESTADOS UNIDOS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current production systems used commercially in the Southeastern United States are discussed in relation to their utility for commercial producers in Mexico. Standard southeastern cultural practices are discussed in detail. Topics covered include pre-plant land preparation, fumigation, nematod...

  14. Investigacion educativa. El sistema escolar en sus diferentes niveles, factores que favorecen o frenan su eficacia y medidas de superacion (Educational Research. The Educational System at Different Levels; Factors Promoting or Hindering Its Efficiency; Possible Improvements.

    ERIC Educational Resources Information Center

    Jimenez Lozano, Blanca; And Others

    This document is an English-language abstract (Approximately 1,500 words) of a study on educational research in Mexico. Chapter one discusses the importance of educational research, in terms of its role both in scientific and technical development; it should use scientific methods so that it will have solid foundations. Chapter two is a survey of…

  15. Hydrochemical tracers in the middle Rio Grande Basin, USA: 1. Conceptualization of groundwater flow

    NASA Astrophysics Data System (ADS)

    Plummer, L. Niel; Bexfield, Laura M.; Anderholm, Scott K.; Sanford, Ward E.; Busenberg, Eurybiades

    Chemical and isotopic data for groundwater from throughout the Middle Rio Grande Basin, central New Mexico, USA, were used to identify and map groundwater flow from 12 sources of water to the basin, evaluate radiocarbon ages, and refine the conceptual model of the Santa Fe Group aquifer system. Hydrochemical zones, representing groundwater flow over thousands to tens of thousands of years, can be traced over large distances through the primarily siliciclastic aquifer system. The locations of the hydrochemical zones mostly reflect the ``modern'' predevelopment hydraulic-head distribution, but are inconsistent with a trough in predevelopment water levels in the west-central part of the basin, indicating that this trough is a transient rather than a long-term feature of the aquifer system. Radiocarbon ages adjusted for geochemical reactions, mixing, and evapotranspiration/dilution processes in the aquifer system were nearly identical to the unadjusted radiocarbon ages, and ranged from modern to more than 30 ka. Age gradients from piezometer nests ranged from 0.1 to 2 year cm-1 and indicate a recharge rate of about 3 cm year-1 for recharge along the eastern mountain front and infiltration from the Rio Grande near Albuquerque. There has been appreciably less recharge along the eastern mountain front north and south of Albuquerque. Des données sur les éléments chimiques et les isotopes présents dans l'eau souterraine prélevée à divers endroits dans le bassin moyen du Rio Grande, au centre du Nouveau-Mexique (É-U), ont permis de déterminer l'existence et l'étendue de douze sources d'eau régionales dans le bassin, d'évaluer les âges radiocarbones et de raffiner le modèle conceptuel du système aquifère du groupe de Santa Fe. Des zones hydro-chimiques qui représentent l'écoulement de l'eau souterraine depuis des dizaines de milliers d'années peuvent être suivies sur de longues distances à travers l'aquifère principalement siliclastique. La position des zones hydro-chimiques reflète principalement la distribution moderne des charges hydrauliques mais est incohérente avec une dépression dans le niveau d'eau dans la partie centre-ouest du bassin, ce qui indique que cette dépression est un élément transitoire du système aquifère plutôt qu'un élément à long terme. Les âges radiocarbones ajustés aux réactions géochimiques et aux processus de mélange et d'évapotranspiration/dilution qui ont lieu dans l'aquifère sont presque identiques aux âges non ajustés et varient de la période moderne jusqu'à 30 ka. Les gradients d'âge établis à partir des nids de piézomètres s'étendent de 0.1 à 2 a cm-1 et suggèrent un taux de recharge d'environ 3 cm a-1 le long du front des montagnes à l'est et pour l'infiltration provenant du Rio Grande près d'Albuquerque. Il y a eu substantiellement moins de recharge le long du front des montagnes à l'est, au nord et au sud d'Albuquerque. Se utilizaron datos químicos e isotópicos de agua subterránea a lo largo de la cuenca central del río Grande, Nuevo México, EEUU, para identificar y mapear el flujo de agua subterránea de 12 fuentes de agua a la cuenca para evaluar edades por medio de radio carbon y para refinar el modelo conceptual del sistema acuífero del Grupo Santa Fé. Se puede establecer zonas hidrotérmicas que representan el flujo de agua subterránea a lo largo de miles a miles de decenas de años en grandes distancias a través del sistema acuífero principalmente siliclástico. Las ubicaciones de las zonas hidroquímicas mayormente reflejan la distribucion de la cabeza hidráulica pre-desarollo moderna pero son inconsistentes con una depresión en los niveles de agua pre-desarollo en la zona central oeste de la cuenca. Esto indica que esta depresión es un rasgo transitorio y no un rasgo de largo plazo del sistema acuífero. Las edades de radio carbon ajustadas para los procesos de reaciones geoquímicas, de mezclado y de evapotranspiración-dilución son casi idénticas a los edades de radio carbon no ajustadas oscilan en un rango desde la modernidad a 30 mil años. Las gradientes de edad de nidos de piezometros van de 0.1 a 2 años cm-1 e indican un sitio de recarga de aproximadamente 3 cm/yr para la recarga a lo largo del frente montañoso oriental e infiltración del río Grande cerca de Albuquerque. Se aprecia una recarga menor a lo largo del frente oriental de montañas al norte y al sur de Albuquerque.

  16. Evolución de estrellas de Helio

    NASA Astrophysics Data System (ADS)

    Panei, J. A.; Benvenuto, O. G.; Althaus, L. G.

    Podríamos identificar a las estrellas de helio con estrellas Wolf-Rayet (WR) que han perdido su envoltura rica en hidrógeno ya sea porque las mismas pertenecen a sistemas binarios o a través de fuertes vientos estelares. Las WR representan una etapa evolucionaria normal de las estrellas masivas, cuya pérdida de masa es >= 3 × 10-5Msolar/yr y la cual es sufrida por la estrella en un tiempo de escala mucho menor que el tiempo en que se produce la quema del He. Esto garantiza la ``homogeneidad'' de las estrellas de helio para nuestros modelos. Este tipo de estrellas serían posibles progenitores de SN tipo Ib y Ic. Aquí presentamos un estudio sobre la evolución de estrellas de helio a partir de la secuencia principal de helio, pasando por el flash de carbono, hasta agotarlo en la región central; como así también la dependencia con la variable masa y con la pérdida de la misma para distintos tipos de masas. Para tal fin hemos utilizado un código de evolución estelar completo que realiza todas las reacciones de Fowler en forma simultánea. También se han tenido en cuenta los procesos de mezcla convectiva, los principales mecanismos de emisión de neutrinos y los efectos de la pérdida de masa. Las opacidades utilizadas fueron las de Rogers & Iglesias (1992). Debido a la pérdida de masa en este tipo de estrellas, hemos encontrado que los perfiles convectivos, la composición química, las condiciones centrales de temperatura y presión, luminosidad y temperatura efectiva dependen en forma esencial de la velocidad de pérdida de masa adoptada, lo que tendría profundas implicaciones en la evolución posterior de estos objetos.

  17. Thanks to 70 years of Inter American Statistical cooperation, the world’s largest integrated census microdata dissemination site www.ipums.org/international

    PubMed Central

    McCAA, ROBERT

    2014-01-01

    Seventy years of Inter American Statistical cooperation, symbolized by the 70th anniversary of Estadística, made possible the construction of IPUMS-International, the world’s largest integrated census microdata dissemination site, www.ipums.org/international. Currently, the site offers access to 238 samples totaling over 540 million person records representing 74 countries. The Americas, which account for only about one-seventh of the world’s population, amount to over one-third (36%) of the person records in the IPUMS-International database. Likewise, 35% of the citations in the IPUMS-International bibliography are for studies focused on Latin America, with about half of these analyzing a single Latin American country. This article discusses salient features of the IPUMS integration methods and system. National Statistical Institutes that have not yet entrusted 2010 census microdata to the initiative are invited to do so. Researchers and teachers are invited to use the data freely in analysis and teaching. Setenta años de cooperación estadística inter-Americana, simbolizada por el 70 aniversario de la revista Estadística, han hecho posible la construcción de IPUMS-internacional, la base en línea de microdatos censales harmonizados más grande del mundo, www.ipums.org/international. Actualmente, IPUMS proporciona acceso a 238 muestras con más de 540 millones de registros individuales de 74 países. Las Américas, que albergan una séptima parte de la población mundial, representan más de un tercio (36%) de todos los registros individuales en la base de datos IPUMS-internacional. Asimismo, el 35% de todas las referencias en la bibliografía de IPUMS son de estudios realizados sobre América Latina, la mitad de éstas basadas en un sólo país de la región. Este artículo presenta las principales características del sistema de integración y difusión de datos de IPUMS. Los Institutos Nacionales de Estadísticas que todavía no ha entregado la muestra de microdatos de la ronda de 2010 son invitados a hacerlo. Los investigadores y profesores son invitados a utilizar los datos de forma gratuita para sus actividades de investigación y docencia. PMID:26028691

  18. Lekking behavior of Anastrepha Fraterculus (Diptera: Tephritidae)

    SciTech Connect

    Segura, D.; Petit-Marty, N.; Cladera, J.; Sciurano, R.; Calcagno, G.; Gomez Cendra, P.; Vilardi, J.; Vera, T.; Allinghi, A.

    2007-03-15

    Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) displays a lek mating system. Males form groups in which they simultaneously display signals (acoustical, visual, or chemical) to attract females with the purpose of mating. Females visit the lek and choose among signaling and courting males to mate. Scarce information is available in A. fraterculus about the main factors involved in female choice and the behavior of displaying males. This information could be important within the context of pest control programs with a sterile insect technique (SIT) component, because departures from normal sexual behavior caused by artificial rearing could affect males' performance in the field. In this study we assessed A. fraterculus male behavior within the leks and analyzed the importance of behavioral and morphological traits on their copulatory success. The existence of preferred places for lek formation was evaluated in field cages with trees inside and analyzed by dividing the trees in sectors according to a 3-dimensional system. Males were individually weighed, marked, and observed every 15 min. Morphometric and behavioral characteristics of successful and unsuccessful males were compared. Most successful males grouped in a region of the tree characterized by the highest light intensity in the first 2 h of the morning. Results showed that pheromone calling activity is positively associated with copulatory success. Copulations were more frequent for males calling inside the lek, indicating that pheromone calling activity and presence in the lek are key factors for copulatory success. A positive association between copulatory success and eye length was found; some characteristics of the face were also associated with copula duration and latency. (author) [Spanish] Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) presenta un sistema de apareamiento tipo lek. Los machos forman grupos y, en forma conjunta, emiten senales (acusticas, visuales, o quimicas) para atraer a las hembras con el proposito de aparearse. Las hembras visitan el lek y eligen entre los machos para copular. La informacion acerca de los principales factores involucrados en la eleccion de la hembra y de la influencia del comportamiento de los machos en los leks en esta eleccion es escasa para A. fraterculus . Esta informacion es importante en el contexto de programas de control que incluyen la Tecnica del Insecto Esteril. En el presente estudio se evaluo el comportamiento sexual de machos de A. fraterculus dentro de los leks, y la asociacion de su comportamiento y de rasgos morfometricos con el exito copulatorio. El lugar preferido de agrupamiento de los machos fue evaluado en jaulas de campo con arboles en su interior y dividiendo el arbol en sectores de acuerdo a un sistema de tres dimensiones. Los machos fueron individualmente pesados, marcados y observados cada quince minutos. Luego de finalizado el ensayo se midieron los rasgos morfometricos. El mayor exito correspondio a machos agrupados en una region del arbol caracterizada por tener la mayor intensidad de luz en las dos primeras horas de la manana. Los resultados mostraron que la actividad de llamado con feromonas esta asociada con el exito copulatorio. Las copulas fueron mas frecuentes para machos que llamaron dentro del lek, indicando que la actividad de llamado con feromonas y la presencia dentro del lek son factores importantes en la obtencion de la copula. Los analisis morfometricos revelaron una asociacion positiva entre el exito copulatorio y el largo del ojo, y que algunas caracteristicas de la cara estan asociadas ademas con la duracion de la copula y la latencia. (author)

  19. Une angiocholite secondaire à un thrombus tumoral d'une tumeur neuroendocrine primitive du foie

    PubMed Central

    Baba, Hicham; Allaoui, Mohamed; Elfahssi, Mohammed; Bounaim, Ahmed; Ali, Abdelmounaim Ait; Oukabli, Mohamed; Sair, Khalid; Zentar, Aziz

    2015-01-01

    Nous rapportons le cas exceptionnel d'une patiente de 54 ans prise en charge pour une angiocholite due à un thrombus tumoral, d'une tumeur neuroendocrine primitive (TNE Ive) du foie, dans la voie biliaire principale. PMID:26966504

  20. Three-dimensional mathematical model to simulate groundwater flow in the lower Palar River basin, southern India

    NASA Astrophysics Data System (ADS)

    Senthilkumar, M.; Elango, L.

    A three-dimensional mathematical model to simulate regional groundwater flow was used in the lower Palar River basin, in southern India. The study area is characterised by heavy ion of groundwater for agricultural, industrial and drinking water supplies. There are three major pumping stations on the riverbed apart from a number of wells distributed over the area. The model simulates groundwater flow over an area of about 392 km2 with 70 rows, 40 columns, and two layers. The model simulated a transient-state condition for the period 1991-2001. The model was calibrated for steady- and transient-state conditions. There was a reasonable match between the computed and observed heads. The transient model was run until the year 2010 to forecast groundwater flow under various scenarios of overpumping and less recharge. Based on the modelling results, it is shown that the aquifer system is stable at the present rate of pumping, excepting for a few locations along the coast where the groundwater head drops from 0.4 to 1.81 m below sea level during the dry seasons. Further, there was a decline in the groundwater head by 0.9 to 2.4 m below sea level in the eastern part of the area when the aquifer system was subjected to an additional groundwater withdrawal of 2 million gallons per day (MGD) at a major pumping station. Les modèles mathématiques en trois dimensions de l'écoulement souterrain régional sont très utiles pour la gestion des ressources en eau souterraine, car ils permettent une évaluation des composantes des processus hydrologiques et fournissent une description physique de l'écoulement de l'eau dans un aquifère. Une telle modélisation a été entreprise sur une partie du bassin inférieur de la rivière Palar, dans le sud de l'Inde. La zone d'étude est caractérisée par des prélèvements importants d'eau souterraine pour l'agriculture, l'industrie et l'eau potable. Il existe trois grandes stations de pompage sur la rivière en plus d'un certain nombre de puits répartis dans cette région. Le modèle simule l'écoulement souterrain dans une région d'environ 392 km2 avec 70 rangs, 40 colonnes et deux couches. Le modèle a fonctionné en régime transitoire en utilisant une approximation aux différences finies d'une équation différentielle partielle en trois dimensions de l'écoulement souterrain dans cet aquifère pour la période 1991-2001. Le modèle a été calibré pour des conditions de régime permanent et transitoire. Les charges hydrauliques calculées étaient en bon accord avec celles observées. Sur la base des résultats du modèle, il est apparu que le système aquifère est stable pour ce taux de pompage, excepté en quelques sites le long de la côte où l'eau marine a pénétré 50-100 m dans les terres. Le modèle transitoire a tourné jusqu'en 2010 afin de prévoir l'écoulement souterrain dynamique pour différents scénarios de pompage excessif et de recharge réduite. Il se produit un abaissement de la piézométrie de la nappe de 0.6 à 0.8 m dans la partie orientale, alors que l'aquifère est soumis à un prélèvement supplémentaire de 8,000 m3/jour à l'une des stations principales de pompage. Même avec le niveau actuel de pompage, la piézométrie de la nappe descendrait sous le niveau de la mer au cours des saisons sèches. Le modèle prédit le fonctionnement du système aquifère sous différentes conditions de stress hydrologique. Los modelos tridimensionales de flujo de aguas subterráneas son útiles para gestionar los recursos hídricos subterráneos, ya que proporcionan una aproximación a los diversos procesos hidrológicos y una descripción cuantitativa del flujo de agua en el acuífero. Se ha desarrollado un estudio de modelación de este tipo en una parte de la cuenca baja del río Palar, en el Sur de la India. Esta zona se caracteriza por las intensas extracciones de aguas subterráneas para usos agrícolas, industriales y domésticos. Hay tres estaciones de bombeo principales en el río, además de numerosos pozos distribuidos por la zona. El modelo simula el flujo de las aguas subterráneas en una superficie de 392 km2 por medio de 70 filas, 40 columnas y 2 capas. El modelo ha sido empleado en condiciones transitorias, por medio de la aproximación en diferencias finitas de las ecuaciones diferenciales parciales en tres dimensiones del flujo en el acuífero durante el período 1991-2001. Se ha calibrado el modelo en condiciones permanentes y transitorias. El ajuste entre los niveles calculados y medidos es razonable. A partir de los resultados de la modelación, se ha obtenido que el sistema acuífero es estable con la tasa de bombeo utilizada, exceptuando unos pocos emplazamientos a lo largo de la costa, donde se ha dado lugar a fenómenos de intrusión marina en una distancia de 50-100 m. El modelo transitorio ha sido ejecutado hasta el año 2010 para predecir el flujo dinámico bajo diversos escenarios de sobreexplotación y de reducción de la recarga. Se produce una disminución en los niveles piezométricos de 0.6 a 0.8 m en la zona oriental, donde el sistema acuífero está sometido a una extracción adicional de 2 millones de galones por día en la estación principal de bombeo. Incluso con las extracciones actuales, los niveles piezométricos se sitúan bajo el nivel del mar durante las épocas secas. El modelo predice el comportamiento de este sistema acuífero bajo varias condiciones de presión hidrológica.

  1. Relation of streams, lakes, and wetlands to groundwater flow systems

    NASA Astrophysics Data System (ADS)

    Winter, Thomas C.

    Surface-water bodies are integral parts of groundwater flow systems. Groundwater interacts with surface water in nearly all landscapes, ranging from small streams, lakes, and wetlands in headwater areas to major river valleys and seacoasts. Although it generally is assumed that topographically high areas are groundwater recharge areas and topographically low areas are groundwater discharge areas, this is true primarily for regional flow systems. The superposition of local flow systems associated with surface-water bodies on this regional framework results in complex interactions between groundwater and surface water in all landscapes, regardless of regional topographic position. Hydrologic processes associated with the surface-water bodies themselves, such as seasonally high surface-water levels and evaporation and transpiration of groundwater from around the perimeter of surface-water bodies, are a major cause of the complex and seasonally dynamic groundwater flow fields associated with surface water. These processes have been documented at research sites in glacial, dune, coastal, mantled karst, and riverine terrains. Résumé Les eaux de surface sont parties intégrantes des systèmes aquifères. Les eaux souterraines interagissent avec les eaux de surface dans presque tous les types d'environnements, depuis les petits ruisseaux, les lacs et les zones humides jusqu'aux bassins versants des vallées des grands fleuves et aux lignes de côte. Il est en général admis que les zones topographiquement hautes sont des lieux de recharge des aquifères et les zones basses des lieux de décharge, ce qui est le cas des grands systèmes aquifères régionaux. La superposition de systèmes locaux, associés à des eaux de surface, à l'organisation régionale d'écoulements souterrains résulte d'interactions complexes entre les eaux souterraines et les eaux de surface dans tous les environnements, quelle que soit la situation topographique régionale. Les processus hydrologiques associés aux eaux de surface elles-mêmes, tels que des niveaux d'eau de surface saisonnièrement hauts et l'évaporation et la transpiration de l'eau souterraine à la périphérie des eaux de surface, sont les causes essentielles de la dynamique complexe et saisonnière des nappes associées aux eaux de surface. Ces processus ont été mis en évidence sur des sites de recherche dans des formations glaciaires, dunaires, littorales, fluviales et de karst couvert. Resumen Los cuerpos de aguas superficiales son partes integrales de los sistemas de flujo subterráneo. El agua subterránea interactúa con la superficial en prácticamente todo tipo de paisajes, desde pequeños torrentes, lagos y humedales, hasta grandes valles fluviales y costas. Aunque se suele asumir que las áreas topográficamente elevadas son zonas de recarga de aguas subterráneas, mientras las áreas topográficamente más bajas lo son de descarga, esto es cierto básicamente para los sistemas de flujo regional. Al superponer los sistemas de flujo local, asociados a los cuerpos de agua superficial, a las condiciones regionales, resultan interacciones complejas, y esto ocurre independientemente de su posición topográfica. Los procesos hidrológicos asociados con los propios cuerpos de agua superficial, como los niveles superficiales máximos estacionales y la evapotranspiración de agua subterránea en los perímetros de cuerpos superficiales, son una de las principales causas de la complejidad y de las variaciones dinámicas de las interacciones entre aguas subterráneas y superficiales. Estos procesos se han documentado en distintas zonas investigadas, incluyendo depósitos glaciares, dunas, áreas costeras, karsts y terrazas fluviales.

  2. Angel of human health: current research updates in toad medicine

    PubMed Central

    Yang, Qian; Zhou, Xuanxuan; Zhang, Meng; Bi, Linlin; Miao, Shan; Cao, Wei; Xie, Yanhua; Sun, Jiyuan; Tang, Haifeng; Li, Ying; Miao, Qing; Wang, Siwang

    2015-01-01

    There are currently 34 genera and 410 species of toads in the world. The medicinal parts of toads mainly include their venom, skin, and clothing. The toad’s venom and skin possess the same chemical components, mainly the toad venom lactone class, and their pharmacological effects primarily include the maintenance of strong heart, antitumor, antivirus, anti-infection, and analgesic effects. So far, the produces from the medicinal raw materials of the toad are widely used clinically around the world, especially in China, Japan, and South Korea. About 50 varieties of medicines are used in the clinical treatment of various complicated diseases in China, such as “Liushen pills” which was popular in the whole world. Toads are mainly used in treating malignant tumors (e.g., liver cancer, gastric cancer, esophageal cancer, colon cancer, cervical cancer, among others), and some major diseases such as hepatitis B. Despite the therapeutic effects of toad-derived medicines on human health, there is insufficient research and development of toad-derived medicines by leading drug companies. In order to harness the beneficial effects of the resources of the toad species, it is the responsibility of global pharmaceutical researchers to develop and generate economically feasible toad-derived therapeutic products, while promoting maximum protection to the resources of the toad species. PMID:25755824

  3. Attenuation of Histone Methyltransferase KRYPTONITE-mediated transcriptional gene silencing by Geminivirus

    PubMed Central

    Sun, Yan-Wei; Tee, Chuan-Sia; Ma, Yong-Huan; Wang, Gang; Yao, Xiang-Mei; Ye, Jian

    2015-01-01

    Although histone H3K9 methylation has been intensively studied in animals and a model plant Arabidopsis thaliana, little is known about the evolution of the histone methyltransferase and its roles in plant biotic stress response. Here we identified a Nicotiana benthamiana homolog of H3K9 histone methyltransferase KRYPTONITE (NbKYP) and demonstrated its fundamental roles on methylation of plant and virus, beside of leading to the suppression of endogenous gene expression and virus replication. NbKYP and another gene encoding DNA methyltransferase CHROMOMETHYLTRANSFERASE 3 (NbCMT3-1) were further identified as the key components of maintenance of transcriptional gene silencing, a DNA methylation involved anti-virus machinery. All three types of DNA methylations (asymmetric CHH and symmetric CHG/CG) were severely affected in NbKYP-silenced plants, but only severe reduction of CHG methylation found in NbCMT3-1-silenced plants. Attesting to the importance of plant histone H3K9 methylation immunity to virus, the virulence of geminiviruses requires virus-encoded trans-activator AC2 which inhibits the expression of KYP via activation of an EAR-motif-containing transcription repressor RAV2 (RELATED TO ABI3 and VP1). The reduction of KYP was correlated with virulence of various similar geminiviruses. These findings provide a novel mechanism of how virus trans-activates a plant endogenous anti-silencing machinery to gain high virulence. PMID:26602265

  4. Herbal mouthwash containing extracts of Baccharis dracunculifolia as agent for the control of biofilm: clinical evaluation in humans.

    PubMed

    Pedrazzi, Vinícius; Leite, Mateus Freire; Tavares, Reisla Cristina; Sato, Sandra; do Nascimento, Glauce Crivelaro; Issa, João Paulo Mardegan

    2015-01-01

    Baccharis dracunculifolia DC (Asteraceae), popularly known as "alecrim-do-campo," is largely distributed in South America, is shown to exhibit protective actions against gastric ulcers, has anti-inflammatory properties, and is hepatoprotective. Several essential oils obtained from Baccharis species possess biological activities, such as antimicrobial and antivirus activities. This randomized controlled trial evaluated the efficacy of B. dracunculifolia in the reduction of dental biofilm, comparing this natural product with other mouthwashes already known in the dental market. In measuring the time after use of mouthwash (t = 1), there was no difference between products (P = 0.602); that is, subjects in the study had a similar PI after the first use. After one week (t = 2), there was no difference between the four products evaluated (P = 0.674), so, all research individuals completed the study with a similar reduction in dental biofilm between themselves but it was different from initial state (Friedman test). It is possible to conclude that B. dracunculifolia had the same efficiency of the materials used to oral hygiene in reduction of dental plaque and, consequently, prevention of dental caries. Thus, we can consider B. dracunculifolia as a good candidate for new material to be implemented in dental care. PMID:25874255

  5. Critical role of phospholipase A2 group IID in age-related susceptibility to severe acute respiratory syndrome-CoV infection.

    PubMed

    Vijay, Rahul; Hua, Xiaoyang; Meyerholz, David K; Miki, Yoshimi; Yamamoto, Kei; Gelb, Michael; Murakami, Makoto; Perlman, Stanley

    2015-10-19

    Oxidative stress and chronic low-grade inflammation in the lungs are associated with aging and may contribute to age-related immune dysfunction. To maintain lung homeostasis, chronic inflammation is countered by enhanced expression of proresolving/antiinflammatory factors. Here, we show that age-dependent increases of one such factor in the lungs, a phospholipase A2 (PLA2) group IID (PLA2G2D) with antiinflammatory properties, contributed to worse outcomes in mice infected with severe acute respiratory syndrome-coronavirus (SARS-CoV). Strikingly, infection of mice lacking PLA2G2D expression (Pla2g2d(-/-) mice) converted a uniformly lethal infection to a nonlethal one (>80% survival), subsequent to development of enhanced respiratory DC migration to the draining lymph nodes, augmented antivirus T cell responses, and diminished lung damage. We also observed similar effects in influenza A virus-infected middle-aged Pla2g2d(-/-) mice. Furthermore, oxidative stress, probably via lipid peroxidation, was found to induce PLA2G2D expression in mice and in human monocyte-derived macrophages. Thus, our results suggest that directed inhibition of a single inducible phospholipase, PLA2G2D, in the lungs of older patients with severe respiratory infections is potentially an attractive therapeutic intervention to restore immune function. PMID:26392224

  6. Laboratory diagnosis of Ebola virus disease and corresponding biosafety considerations in the China Ebola Treatment Center.

    PubMed

    Huang, Qing; Fu, Wei-Ling; You, Jian-Ping; Mao, Qing

    2016-10-01

    Ebola virus disease (EVD), caused by Ebola virus (EBOV), is a potent acute infectious disease with a high case-fatality rate. Etiological and serological EBOV detection methods, including techniques that involve the detection of the viral genome, virus-specific antigens and anti-virus antibodies, are standard laboratory diagnostic tests that facilitate confirmation or exclusion of EBOV infection. In addition, routine blood tests, liver and kidney function tests, electrolytes and coagulation tests and other diagnostic examinations are important for the clinical diagnosis and treatment of EVD. Because of the viral load in body fluids and secretions from EVD patients, all body fluids are highly contagious. As a result, biosafety control measures during the collection, transport and testing of clinical specimens obtained from individuals scheduled to undergo EBOV infection testing (including suspected, probable and confirmed cases) are crucial. This report has been generated following extensive work experience in the China Ebola Treatment Center (ETC) in Liberia and incorporates important information pertaining to relevant diagnostic standards, clinical significance, operational procedures, safety controls and other issues related to laboratory testing of EVD. Relevant opinions and suggestions are presented in this report to provide contextual awareness associated with the development of standards and/or guidelines related to EVD laboratory testing. PMID:26952811

  7. Design, Synthesis and Structure-Activity Relationship Optimization of Lycorine Derivatives for HCV Inhibition

    PubMed Central

    Chen, Duozhi; Cai, Jieyun; Cheng, Junjun; Jing, Chenxu; Yin, Junlin; Jiang, Jiandong; Peng, Zonggen; Hao, Xiaojiang

    2015-01-01

    Lycorine is reported to be a multifunctional compound. We previously showed that lycorine is an HCV inhibitor with strong activity. Further research on the antivirus mechanism indicated that lycorine does not affect the enzymes that are indispensable to HCV replication but suppresses the expression of Hsc70 in the host cell to limit HCV replication. However, due to the cytotoxicity and apoptosis induction of lycorine, lycorine is unsafe to be a anti-HCV agent for clinical application. As a result of increasing interest, its structure was optimized for the first time and a novel series of lycorine derivatives was synthesized, all of which lost their cytotoxicity to different degrees. Structure-activity analysis of these compounds revealed that disubstitution on the free hydroxyl groups at C1 and C2 and/or degradation of the benzodioxole group would markedly reduce the cytotoxicity. Furthermore, an α, β-unsaturated ketone would improve the HCV inhibitory activity of lycorine. The C3-C4 double bond is crucial to the anti-HCV activity because hydrogenation of this double bond clearly weakened HCV inhibition. PMID:26443922

  8. [Mechanisms of action of LB-plaferon and fenovin in the cases of Rausche virus leukemia].

    PubMed

    Mikeladze, R B; Kupradze, S A; Korsantiia, B M

    2005-01-01

    The aim of our investigation was to examine the mechanisms of protective features of plaferon LB and fenovit in mice infected with Rausche virus. It was found that in erythroblasts from peripheral blood and spleen, which appeared 12-14 days after infection, the highest percent of determined virus antigens was approximately 47% (range 35,5 to 58,4) which was followed by decrease of the concentration of virus antigens (between 5-12%) in following days and increase of uninfected cells as a result of division of non-contaminated erythroblasts. Mechanism of action of plaferon LB and fenovit was manifested in the reconstitution of mechanisms of apoptosis among erythroblasts, which did not contain synthesized Rausche virus. Impairment of functional activity and antivirus resistance of macrophagal phagocytes are playing an important role not only in the pathogenesis of murine viral leukemia caused by Rausche virus, but also during human leukemia. Correction of functional status of above -- mentioned diseases using plaferon LB and fenovit is presenting as a new and prospective way. PMID:16148383

  9. Virus-Specific Antibody, in the Absence of T Cells, Mediates Demyelination in Mice Infected with a Neurotropic Coronavirus

    PubMed Central

    Kim, Taeg S.; Perlman, Stanley

    2005-01-01

    Mice infected with mouse hepatitis virus strain JHM develop an inflammatory demyelinating disease in the central nervous system with many similarities to human multiple sclerosis. The mouse disease is primarily immune-mediated because demyelination is not detected in JHM-infected mice lacking T or B cells but does occur after transfer of JHM-specific T cells. Although less is known about the ability of antibodies to mediate demyelination, the presence of oligoclonally expanded B cells and high concentrations of antibodies (against self or infectious agents) in the central nervous system of many multiple sclerosis patients suggests that antibodies may also contribute to myelin destruction. Here, we show that anti-JHM antibodies, in the absence of T or B cells, caused demyelination in JHM-infected mice. Anti-JHM antibody was detected adjacent to areas of demyelination, consistent with a direct interaction between antibody and infected cells. Demyelination was reduced by 85 to 90% in infected RAG1−/− mice lacking normal expression of activating Fc receptors (FcRγ−/−) and by ∼76% when complement was depleted by treatment with cobra venom factor. These data demonstrate that JHM-specific antibodies are sufficient to cause demyelination and that myelin destruction in the presence of anti-virus antibodies results from a combination of complement- and Fc receptor-dependent mechanisms. PMID:15743792

  10. Avian leukosis virus subgroup J triggers caspase-1-mediated inflammatory response in chick livers.

    PubMed

    Liu, Xue-Lan; Shan, Wen-Jie; Jia, Li-Juan; Yang, Xu; Zhang, Jin-Jing; Wu, Ya-Rong; Xu, Fa-Zhi; Li, Jin-Nian

    2016-04-01

    Many pathogens trigger caspase-1-mediated innate immune responses. Avian leukosis virus subgroup J (ALV-J) causes serious immunosuppression and diverse tumors in chicks. The caspase-1 inflammasome mechanism of response to ALV-J invading remains unclear. Here we investigated the expression of caspase-1, the inflammasome adaptor NLRP3, IL-1β and IL-18 in response to ALV-J infection in the liver of chick. We found caspase-1 mRNA expression was elevated at 5dpi and peaked at 7dpi in ALV-J infected animals. Corresponding to this, the expressions of NLRP3 and proinflammatory cytokines IL-1β and IL-18 were significantly increased at 5 or 7dpi. In addition, caspase-1 protein expression and inflammatory cell infiltration were induced after virus infection. These results indicated that ALV-J infection could trigger the caspase-1- mediated inflammatory response in chicks. Thus, an understanding of the inflammatory responses can provide a better insight into the pathogenicity of ALV-J and a possible anti-virus target for ALV-J infection. PMID:26811903

  11. Hydrolysis is the dominating in vivo metabolism pathway for arctigenin: identification of novel metabolites of arctigenin by LC/MS/MS after oral administration in rats.

    PubMed

    Gao, Qiong; Zhang, Yufeng; Wo, Siukwan; Zuo, Zhong

    2013-04-01

    The phenylpropanoid dibenzylbutyrolactone lignan arctigenin, a key component found in Arctium lappa, or burdock, has been reported with a variety of therapeutic effects including anticancer, anti-inflammation, and antivirus effects. Using LC/MS/MS, three novel metabolites of arctigenin, namely, arctigenic acid, arctigenin-4-O'-glucuronide, and 4-O-demethylarctigenin were identified after oral administration of arctigenin in rats for the first time. Another potential metabolite of arctigenin, arctigenin-4'-O-sulfate, was identified in vitro but not in vivo. Structure of arctigenic acid, the major metabolite of arctigenin, was confirmed by 13C-NMR and 1H-NMR. Rapid hydrolysis in plasma was identified as the major metabolic pathway of arctigenin after its oral administration, with Vmax, Km, and Clint in rat plasma determined to be 2.21 ± 0.12 nmol/min/mg, 89.12 ± 9.44 µM, and 24.74 µL/min/mg, respectively. Paraoxonase 1 was further confirmed to be the enzyme responsible for arctigenin hydrolysis, with Vmax, Km, and Clint determined to be 55.39 ± 1.49 nmol/min/mg, 300.3 ± 10.86 µM, and 184.45 µL/min/mg, respectively. PMID:23519790

  12. The interplay between Epstein-Barr virus and the immune system: a rationale for adoptive cell therapy of EBV-related disorders

    PubMed Central

    Merlo, Anna; Turrini, Riccardo; Dolcetti, Riccardo; Martorelli, Debora; Muraro, Elena; Comoli, Patrizia; Rosato, Antonio

    2010-01-01

    The Epstein-Barr virus has evolved a plethora of strategies to evade immune system recognition and to establish latent infection in memory B cells, where the virus resides lifelong without any consequence in the majority of individuals. However, some imbalances in the equilibrium between the inherent virus transforming properties and the host immune system can lead to the development of different tumors, such as lymphoproliferative disorders, Hodgkin’s lymphoma, Burkitt’s lymphoma, and nasopharyngeal carcinoma. The expression of viral antigens in malignant cells makes them suitable targets for immunotherapeutic approaches, which are mainly based on the ex vivo expansion of EBV-specific T cells. Indeed, the infusion of virus-specific cytotoxic T lymphocytes has proved not only to be safe and effective, but also capable of restoring or inducing a protective anti-virus immunity, which is lacking, albeit to a different extent, in every EBV-driven malignancy. The purpose of this review is to summarize the results of adoptive immunotherapy approaches for EBV-related malignancies, with particular emphasis on the immunological and virological aspects linked to the clinical responses obtained. Data collected confirm the clinical relevance of the use of EBV-specific cytotoxic T lymphocytes in the field of adoptive immunotherapy and suggest the increasing importance of this approach also against other tumors, concurrent with the increasing knowledge of the intimate and continuous interplay between the virus and the host immune system. PMID:20421267

  13. Cell-based analysis of Chikungunya virus membrane fusion using baculovirus-expression vectors.

    PubMed

    Kuo, Szu-Cheng; Chen, Ying-Ju; Wang, Yu-Ming; Kuo, Ming-Der; Jinn, Tzyy-Rong; Chen, Wen-Shuo; Chang, Yen-Chung; Tung, Kuo-Lun; Wu, Tzong-Yuan; Lo, Szecheng J

    2011-08-01

    Chikungunya virus infection has emerged in many countries over the past decade. There are no effective drugs for controlling the disease. To develop cell-based system for screening anti-virus drugs, a bi-cistronic baculovirus expression system was utilized to co-express viral structural proteins C (capsid), E2 and E1 and the enhanced green fluorescence protein (EGFP) in Spodoptera frugiperda insect cells (Sf21). The EGFP-positive Sf21 cells fused with each other and with uninfected cells to form a syncytium, allowing characterization of cholesterol and low pH requirements for syncytium formation. Western blot analysis showed three structural proteins were expressed in baculovirus infected cells. The structural proteins of Chikungunya virus that is required for cell fusion was determined with various recombinant baculoviruses bearing different lengths of the viral structural protein genes. Protein E1 was required for cell fusion and indicating that Chikungunya viral membrane fusion was a class II membrane fusion. It was also demonstrated that the heterologous expression of alphavirus monomeric E1 can induce insect cell fusions. Furthermore, this cell-based system provides a model for studying class II viral membrane fusion. PMID:21619896

  14. Silver nanoparticles in combination with acetic acid and zinc oxide quantum dots for antibacterial activities improvement-A comparative study

    NASA Astrophysics Data System (ADS)

    Sedira, Sofiane; Ayachi, Ahmed Abdelhakim; Lakehal, Sihem; Fateh, Merouane; Achour, Slimane

    2014-08-01

    Due to their remarkable antibacterial/antivirus properties, silver nanoparticles (Ag NPs) and zinc oxide quantum dots (ZnO Qds) have been widely used in the antimicrobial field. The mechanism of action of Ag NPs on bacteria was recently studied and it has been proven that Ag NPs exerts their antibacterial activities mainly by the released Ag+. In this work, Ag NPs and ZnO Qds were synthesized using polyol and hydrothermal method, respectively. It was demonstrated that Ag NPs can be oxidized easily in aqueous solution and the addition of acetic acid can increase the Ag+ release which improves the antibacterial activity of Ag NPs. A comparative study between bactericidal effect of Ag NPs/acetic acid and Ag NPs/ZnO Qds on Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus was undertaken using agar diffusion method. The obtained colloids were characterized using UV-vis spectroscopy, Raman spectrometry, X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM).

  15. Biological properties of garlic and garlic-derived organosulfur compounds.

    PubMed

    Iciek, Małgorzata; Kwiecień, Inga; Włodek, Lidia

    2009-04-01

    Medicinal properties of garlic (Allium sativum) have been widely known and used since ancient times till the present. Garlic enhances immune functions and has antibacterial, antifungal and antivirus activities. It is known to prevent platelet aggregation, and to have hypotensive and cholesterol- and triglyceride-lowering properties, although the latter features have been questioned. This review is focused on anticancer efficacy of Allium sativum, and attempts to explain the mechanisms of this action. Medicinal properties of garlic rely upon organosulfur compounds mostly derived from alliin. Organosulfur compounds originating from garlic inhibit carcinogen activation, boost phase 2 detoxifying processes, cause cell cycle arrest mostly in G2/M phase, stimulate the mitochondrial apoptotic pathway, increase acetylation of histones. Garlic-derived sulfur compounds influence also gap-junctional intercellular communication and participate in the development of multidrug resistance. This review presents also other little known aspects of molecular action of garlic-derived compounds, like modulation of cellular redox state, involvement in signal transduction and post-translational modification of proteins by sulfane sulfur or by formation of mixed disulfides (S-thiolation reactions). PMID:19253339

  16. Investigating weaknesses in Android certificate security

    NASA Astrophysics Data System (ADS)

    Krych, Daniel E.; Lange-Maney, Stephen; McDaniel, Patrick; Glodek, William

    2015-05-01

    Android's application market relies on secure certificate generation to establish trust between applications and their users; yet, cryptography is often not a priority for application developers and many fail to take the necessary security precautions. Indeed, there is cause for concern: several recent high-profile studies have observed a pervasive lack of entropy on Web-systems leading to the factorization of private keys.1 Sufficient entropy, or randomness, is essential to generate secure key pairs and combat predictable key generation. In this paper, we analyze the security of Android certificates. We investigate the entropy present in 550,000 Android application certificates using the Quasilinear GCD finding algorithm.1 Our results show that while the lack of entropy does not appear to be as ubiquitous in the mobile markets as on Web-systems, there is substantial reuse of certificates only one third of the certificates in our dataset were unique. In other words, we find that organizations frequently reuse certificates for different applications. While such a practice is acceptable under Google's specifications for a single developer, we find that in some cases the same certificates are used for a myriad of developers, potentially compromising Android's intended trust relationships. Further, we observed duplicate certificates being used by both malicious and non-malicious applications. The top 3 repeated certificates present in our dataset accounted for a total of 11,438 separate APKs. Of these applications, 451, or roughly 4%, were identified as malicious by antivirus services.

  17. Spectroscopy characterization of the interaction between brevifolin carboxylic acid and bovine serum albumin.

    PubMed

    Tian, Jianniao; Xie, Yuhuan; Zhao, Yanchun; Li, Caifeng; Zhao, Shulin

    2011-01-01

    Themechanism of binding of the antivirus drug, brevifolin carboxylic acid (BCA) with bovine serum albumin (BSA) was investigated by steady-state and time-resolved fluorescence, circular dichroism (CD), Fourier transform infrared (FT-IR) and Raman spectroscopy under pseudo-physiological conditions for the first time. A strong fluorescence quenching was observed and the quenching mechanism was considered as static quenching. Various binding parameters were evaluated. The quantitative analysis of CD spectral data revealed that the a-helical content of BSA increased from 48.91% (in free BSA) to 52.46% (in bound form) in the presence of BCA. Based on the Förster's theory of non-radiation energy transfer, the relation of the binding average distance r between the donor (BSA) and acceptor (BCA) and acceptor concentration was determined. The changes in association constants of BCA-BSA in the presence of the common ions are also discussed. From the CD, FT-IR, time-resolved fluorescence and Raman spectroscopic results, it is apparent that the interaction of BCA with BSA causes a conformational change in the protein, and the Trp and Tyr residues are buried in more hydrophobic surroundings. BCA mainly binds to residue Trp 212 located in domain II of BSA by hydrophobic interaction and hydrogen bond. PMID:20737652

  18. A Novel Method for Simultaneous Production of Two Ribosome-Inactivating Proteins, α-MMC and MAP30, from Momordica charantia L

    PubMed Central

    Liu, Shuangfeng; Fan, Xiang; Li, Gangrui; Meng, Yanfa

    2014-01-01

    Alpha-momorcharin (α-MMC) and momordica anti-HIV protein (MAP30) from Momordica charantia L. have been confirmed to possess anti-tumor and anti-virus activities. Traditional purification methods of these two ribosome-inactivating proteins (RIPs) were separate which was time consuming and cost effective as well as low efficient. In order to obtain sufficient samples for researches, a strategy combining ion-exchange and gel filtration chromatography was developed and optimized in this study. Using this novel purification method, averagely 1162 mg of α-MMC and 535 mg of MAP30 were obtained from 400 g of Momordica charantia L seeds. The homogeneities of them were assessed by electrophoresis analysis. Determination of molecular weights of α-MMC and MAP30 were 28.585 kDa and 29.094 kDa by MALDI-TOF/TOF and pI were 9.02 and 9.12, respectively. The single glycoproteins were identified by Periodate-Schiff's base (PAS) and the saccharide content was tested to be 1.25% and 1.1% by anthrone-sulfuric acid method. Biological activities were evidenced by their ability to inhibit proliferation of lung adenocarcinoma A549 cell and to convert supercoiled plasmid pUC18 into relaxed forms. Finally, we also found that both two RIPs exhibited no superoxide dismutase (SOD) activity. PMID:25003606

  19. Ginseng Berry Extract Promotes Maturation of Mouse Dendritic Cells

    PubMed Central

    Zhang, Wei; Cho, Si-Young; Xiang, Gao; Min, Kyung-Jin; Yu, Qing; Jin, Jun-O

    2015-01-01

    Ginseng extract has been shown to possess certain anti-virus, anti-tumor and immune-activating effects. However, the immunostimulatory effect of ginseng berry extract (GB) has been less well characterized. In this study, we investigated the effect of GB on the activation of mouse dendritic cells (DCs) in vitro and in vivo. GB treatment induced up-regulation of co-stimulatory molecules in bone marrow-derived DCs (BMDCs). Interestingly, GB induced a higher degree of co-stimulatory molecule up-regulation than ginseng root extract (GR) at the same concentrations. Moreover, in vivo administration of GB promoted up-regulation of CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen DCs. GB also promoted the generation of Th1 and Tc1 cells. Furthermore, Toll like receptor 4 (TLR4) and myeloid differentiation primary response 88 (MyD88) signaling pathway were essential for DC activation induced by GB. In addition, GB strongly prompted the proliferation of ovalbumin (OVA)-specific CD4 and CD8 T cells. Finally, GB induced DC activation in tumor-bearing mice and the combination of OVA and GB treatment inhibited B16-OVA tumor cell growth in C57BL/6 mice. These results demonstrate that GB is a novel tumor therapeutic vaccine adjuvant by promoting DC and T cell activation. PMID:26090808

  20. Phenylpropanoids as naturally occurring antioxidants: from plant defense to human health.

    PubMed

    Korkina, L G

    2007-01-01

    Phenylpropanoids (PPs) belong to the largest group of secondary metabolites produced by plants, mainly, in response to biotic or abiotic stresses such as infections, wounding, UV irradiation, exposure to ozone, pollutants, and other hostile environmental conditions. It is thought that the molecular basis for the protective action of phenylpropanoids in plants is their antioxidant and free radical scavenging properties. These numerous phenolic compounds are major biologically active components of human diet, spices, aromas, wines, beer, essential oils, propolis, and traditional medicine. Last few years, much interest has been attracted to natural and synthetic phenylpropanoids for medicinal use as antioxidant, UV screens, anticancer, anti-virus, anti-inflammatory, wound healing, and antibacterial agents. They are of great interest for cosmetic and perfume industries as active natural ingredients. In the present review, the metabolic pathways of phenylpropanoid biosynthesis in plants and the mechanism of phenylpropanoid-mediated plant defense are described. Learning from plants, free radical-driven, molecular and cellular processes modulated by phenylpropanoids in human cell cultures in vitro and in the in vivo animal models of tumors, inflammation, and cellular damage are also reviewed. PMID:17519109

  1. SEPARATION AND PURIFICATION OF TWO MINOR COMPOUNDS FROM RADIX ISATIDIS BY INTEGRATIVE MPLC AND HSCCC WITH PREPARATIVE HPLC

    PubMed Central

    Liang, Zhenjie; Li, Bin; Liang, Yong; Su, Yaping; Ito, Yoichiro

    2014-01-01

    Radix isatidis has been widely used as a Chinese traditional medicine for its anti-virus and anticancer activities where the minor components may contribute to these beneficial pharmaceutical effects. In order to enrich the target minor compounds effectively and rapidly, extraction, medium-pressure liquid chromatography (MPLC), high-speed countercurrent chromatography (HSCCC) and preparative high-performance liquid chromatography (pre-HPLC) were integratively used for separation and purification of two target minor compounds indole-3-acetonitrile-6-O-β-D-glucopyranoside (target 1) and clemastanin B (target 2) in the present study. Radix isatidis was dried, pulverized and extracted with 50% methanol at room temperature, then concentrated and subjected to pretreatment with D-101 macroporous resin chromatography and extraction by MPLC. The first target compound was separated by MPLC at the purity raised to 70–80%, but without the second minor compounds which were irreversibly adsorbed by C18 solid support. Therefore, the second target compound in the crude extract was directly separated by HSCCC at purity of 80–90%. Finally these refined samples were further separated by pre-HPLC to obtain a high purity at 98–99%. The chemical structure identification of each target compound was carried out by IR, ESI-MS and 1H NMR. PMID:25745338

  2. Subversion and piracy: DNA viruses and immune evasion.

    PubMed

    Haig, D M

    2001-06-01

    During the co-evolution of viruses with their vertebrate hosts, the DNA viruses have acquired an impressive array of immunomodulatory genes to combat host immune responses and their hosts have developed a sophisticated immune system to contain virus infections. In order to replicate, the viruses have evolved mechanisms to inhibit key host anti-virus responses that include apoptosis, interferon production, chemokine production, inflammatory cytokine production, and the activity of cytotoxic T-cells, natural killer cells and antibody. In addition, some of the viruses encode cytokine or chemokine homologues that recruit or expand cell numbers for infection or that subvert the host cellular response from a protective response to a benign one. The specificity of the viral immunomodulatory molecules reflects the life cycle and the pathogenesis of the viruses. Herpesviruses achieve latency in host cells by inducing cell survival and protecting infected cells from immune recognition. This involves interference with cell signal transduction pathways. Many of the viral immunomodulatory proteins are homologues of host proteins that appear to have been pirated from the host and reassorted in the virus genomes. Some of these have unique functions and indicate novel or important aspects of both viral pathogenesis and host immunity to viruses. The specific example of orf virus infection of sheep is described. PMID:11676616

  3. Suppressive Effects of the Site 1 Protease (S1P) Inhibitor, PF-429242, on Dengue Virus Propagation

    PubMed Central

    Uchida, Leo; Urata, Shuzo; Ulanday, Gianne Eduard L.; Takamatsu, Yuki; Yasuda, Jiro; Morita, Kouichi; Hayasaka, Daisuke

    2016-01-01

    Dengue virus (DENV) infection causes one of the most widespread mosquito-borne diseases in the world. Despite the great need, effective vaccines and practical antiviral therapies are still under development. Intracellular lipid levels are regulated by sterol regulatory elements-binding proteins (SREBPs), which are activated by serine protease, site 1 protease (S1P). Small compound PF-429242 is known as a S1P inhibitor and the antivirus effects have been reported in some viruses. In this study, we examined the anti-DENV effects of PF-429242 using all four serotypes of DENV by several primate-derived cell lines. Moreover, emergence of drug-resistant DENV mutants was assessed by sequential passages with the drug. DENV dependency on intracellular lipids during their infection was also evaluated by adding extracellular lipids. The addition of PF-429242 showed suppression of viral propagation in all DENV serotypes. We showed that drug-resistant DENV mutants are unlikely to emerge after five times sequential passages through treatment with PF-429242. Although the levels of intracellular cholesterol and lipid droplets were reduced by PF-429242, viral propagations were not recovered by addition of exogenous cholesterol or fatty acids, indicating that the reduction of LD and cholesterol caused by PF-429242 treatment is not related to its mechanism of action against DENV propagation. Our results suggest that PF-429242 is a promising candidate for an anti-DENV agent. PMID:26875984

  4. Effects of Nidus Vespae extract and chemical fractions on the growth and acidogenicity of oral microorganisms.

    PubMed

    Xiao, Jin; Liu, Yuan; Zuo, Yu Ling; Li, Ji Yao; Ye, Ling; Zhou, Xue Dong

    2006-09-01

    Nidus Vespae is the honeycomb of Polistes Olivaceous (De Geer), P. Japonicus Saussure, and Parapolybiavaria Fabricius. It is known to have a number of pharmacological effects, including antimicrobial, anti-inflammatory, anti-virus, anti-tumor and anesthetic properties. The present study evaluated the antimicrobial activity and acid inhibition properties of extracts and chemical fractions of Nidus Vespae. The raw material was first extracted using 95% ethanol/water. Subsequent fractions were prepared from this extract using cyclohexane/ethyl acetate, petroleum ether/ethyl acetate, and chloroform/methanol. For the antimicrobial activity assays, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined using the microdilution method. The chloroform/methanol (Chl/MeOH) fraction showed the highest antibacterial activities with a MIC of 8-16mg/ml and an MBC of 16-32mg/ml. In addition, the extract and chemical fractions of Nidus Vespae showed a remarkable capacity for inhibiting the acid production of common oral bacteria at sub-MIC concentrations. Sub-MIC levels of the petroleum ether/ethyl acetate fraction significantly inhibited acid production by Streptococcus mutans ATCC 25175. The significant antiacidogenic activity demonstrated by Nidus Vespae shows it to be a promising source of novel anticariogenic agents. PMID:16723116

  5. From Intrusion Detection to Self Protection

    SciTech Connect

    Frincke, Deb; Wespi, Andreas; Zamboni, Diego

    2007-04-11

    Modern computer systems have become so complex and interdependent that the traditional model of system defense, utilizing layers and including an intrusion detection system that provides alerts to a human who responds to them, is becoming unfeasible. Effective human-guided real-time responses are no longer a reasonable expectation for large scale systems--this is particularly troublesome because a failure to respond correctly and rapidly can have disastrous consequences. In an ideal world, our systems would automatically detect and respond to threats of all kinds, including but not limited to automated attacks, human-guided attacks, and the constant onslaught of unsolicited email (spam). Traditionally, these threats have been dealt with by separate communities--the anti-virus community, the intrusion-detection/firewall community, and the anti-spam community. Today however, we see an increasing need for integrating different technologies toward achieving a common goal. In this special issue, we surveyed the research community with the intent of identifying novel, multidisciplinary and integrated approaches to system defense that contribute towards development of true self-protecting and self-healing systems. The result is reflected in the articles we selected.

  6. Status of hepatitis C virus vaccination: Recent update.

    PubMed

    Abdelwahab, Kouka Saadeldin; Ahmed Said, Zeinab Nabil

    2016-01-14

    Hepatitis C virus (HCV) infection is still a major public health problem worldwide since its first identification in 1989. At the start, HCV infection was post-transfusion viral infection, particularly in developing countries. Recently, due to iv drug abuse, HCV infection became number one health problem in well-developed countries as well. Following acute HCV infection, the innate immune response is triggered in the form of activated coordinated interaction of NK cells, dendritic cells and interferon α. The acquired immune response is then developed in the form of the antibody-mediated immune response (ABIR) and the cell-mediated immune response (CMIR). Both are responsible for clearance of HCV infection in about 15% of infected patients. However, HCV has several mechanisms to evade these antivirus immune reactions. The current review gives an overview of HCV structure, immune response and viral evasion mechanisms. It also evaluates the available preventive and therapeutic vaccines that induce innate, ABIR, CMIR. Moreover, this review highlights the progress in recent HCV vaccination studies either in preclinical or clinical phases. The unsatisfactory identification of HCV infection by the current screening system and the limitations of currently available treatments, including the ineligibility of some chronic HCV patients to such antiviral agents, mandate the development of an effective HCV vaccine. PMID:26811632

  7. Ultra-high performance liquid chromatography with linear ion trap-Orbitrap hybrid mass spectrometry combined with a systematic strategy based on fragment ions for the rapid separation and characterization of components in Stellera chamaejasme extracts.

    PubMed

    Wang, Zhixin; Qu, Yang; Wang, Li; Zhang, Xiaozhe; Xiao, Hongbin

    2016-04-01

    Stellera chamaejasme, a famous toxic herb, has been used in traditional Chinese medicine to treat various diseases. For decades, increasing attention in modern pharmacological studies has been drawn to S. chamaejasme because of its potential anti-tumor, anti-virus, and anti-fungus activities. However, due to the intrinsic complexity of chemical constitutes, hardly any investigations formed an overall recognition for the chemical profiles of this herb. In this study, a rapid and sensitive ultra-high performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry method was developed to characterize the chemical components of S. chamaejasme extracts. Based on optimized ultra-high performance liquid chromatography and mass spectrometry conditions and systematic fragment ions-based strategy, a total of 47 components including flavones, diterpenes, coumarins, and lignans were simultaneously detected and identified or tentatively identified for the first time. The MS(n) fragmentation patterns of all the characterized compounds in positive or negative electrospray ionization modes were also explored and summarized. These results provided essential data for further pharmacological research on S. chamaejasme. Moreover, the method was demonstrated to be an efficient tool for rapid qualitative analysis of secondary metabolites from natural resources. PMID:26861765

  8. The virus-induced protein APOBEC3G inhibits anoikis by activation of Akt kinase in pancreatic cancer cells

    PubMed Central

    Wu, Jia; Pan, Tian-Hui; Xu, Song; Jia, Li-Tao; Zhu, Lin-Lin; Mao, Jian-Shan; Zhu, Yong-Liang; Cai, Jian-Ting

    2015-01-01

    Pancreatic cancer is one of the more common cancers with a poor prognosis. Some varieties of cancer are related to virus infection. As a virus-induced protein, APOBEC3G (A3G) presents extensive anti-virus ability, but the role of A3G in pancreatic cancer was previously unknown. The expression of A3G in pancreatic cancer was examined using TaqMan real-time qPCR, immunohistochemical and immunofluorescent staining. Subsequently, the role of A3G in pancreatic cancer was evaluated in vivo using the tumor xenograft model. Anoikis was detected by colony formation assay and flow cytometry in vitro. The Akt kinase activity and target protein PTEN were examined by co-immunoprecipitation and immunoblot. The virus-induced protein A3G was significantly up-regulated in pancreatic cancer, and the up-regulation of A3G promoted xenograft tumor formation. A3G inactivated PTEN by binding to the C2 tensin-type and PDZ domains, thereby inducing anoikis resistance through Akt activation. Our results demonstrate that the up-regulation of A3G in pancreatic cancer cells induces anoikis resistance, and they provide novel insight into the mechanism by which A3G affects the malignant behavior of pancreatic cancer cells. PMID:26178819

  9. p-Coumaric acid and its conjugates: dietary sources, pharmacokinetic properties and biological activities.

    PubMed

    Pei, Kehan; Ou, Juanying; Huang, Junqing; Ou, Shiyi

    2016-07-01

    p-Coumaric acid (4-hydroxycinnamic acid) is a phenolic acid that has low toxicity in mice (LD50 = 2850 mg kg(-1) body weight), serves as a precursor of other phenolic compounds, and exists either in free or conjugated form in plants. Conjugates of p-coumaric acid have been extensively studied in recent years due to their bioactivities. In this review, the occurrence, bioavailability and bioaccessibility of p-coumaric acid and its conjugates with mono-, oligo- and polysaccharides, alkyl alcohols, organic acids, amine and lignin are discussed. Their biological activities, including antioxidant, anti-cancer, antimicrobial, antivirus, anti-inflammatory, antiplatelet aggregation, anxiolytic, antipyretic, analgesic, and anti-arthritis activities, and their mitigatory effects against diabetes, obesity, hyperlipaemia and gout are compared. Cumulative evidence from multiple studies indicates that conjugation of p-coumaric acid greatly strengthens its biological activities; however, the high biological activity but low absorption of its conjugates remains a puzzle. © 2015 Society of Chemical Industry. PMID:26692250

  10. Tyrosinase Inhibitory Effects and Antioxidative Activities of Saponins from Xanthoceras Sorbifolia Nutshell

    PubMed Central

    Zhang, Hongmei; Zhou, Quancheng

    2013-01-01

    Certain saponins are bioactive compounds with anticancer, antivirus and antioxidant activities. This paper discussed inhibitory effects of saponins from Xanthoceras Sorbifolia on tyrosinase, through the research of the rate of tyrosinase catalyzed L-DOPA oxidation. The inhibition rate of tyrosinase activity presented non-linear changes with the saponins concentration. The rate reached 52.0% when the saponins concentration was 0.96 mg/ml. Antioxidant activities of saponins from Xanthoceras Sorbifolia were evaluated by using hydroxyl and superoxide radical scavenging assays. The hydroxyl radical scavenging effects of the saponins were 15.5–68.7%, respectively at the concentration of 0.18–2.52 mg/ml. The superoxide radical scavenging activity reduced from 96.6% to 7.05% with the time increasing at the concentration of 1.44 mg/ml. All the above antioxidant evaluation indicated that saponins from Xanthoceras Sorbifolia exhibited good antioxidant activity in a concentration- dependent manner. PMID:23990897

  11. Antiviral activity of Rheum palmatum methanol extract and chrysophanol against Japanese encephalitis virus.

    PubMed

    Chang, Shu-Jen; Huang, Su-Hua; Lin, Ying-Ju; Tsou, Yi-Yun; Lin, Cheng-Wen

    2014-01-01

    Rheum palmatum, Chinese traditional herb, exhibits a great variety of anti-cancer and anti-viruses properties. This study rates antiviral activity of R. palmatum extracts and its components against Japanese encephalitis virus (JEV) in vitro. Methanol extract of R. palmatum contained higher levels of aloe emodin, chrysophanol, rhein, emodin and physcion than water extract. Methanol extract (IC₅₀ = 15.04 μg/ml) exhibited more potent inhibitory effects on JEV plaque reduction than water extract (IC₅₀ = 51.41 μg/ml). Meanwhile, IC₅₀ values determined by plaque reduction assay were 15.82 μg/ml for chrysophanol and 17.39 μg/ml for aloe-emodin, respectively. Virucidal activity of agents correlated with anti-JEV activity, while virucidal IC₅₀ values were 7.58 μg/ml for methanol extract, 17.36 μg/ml for water extract, 0.75 μg/ml for chrysophanol and 0.46 μg/ml for aloe-emodin, respectively. In addition, 10 μg/ml of extract, chrysophanol or aloe emodin caused 90 % inhibition of JEV yields in cells and significantly activated gamma activated sequence-driven promoters. Hence, methanol extract of R. palmatum and chrysophanol with high therapeutic index might be useful for development of antiviral agents against JEV. PMID:24395532

  12. Interferon-inducible antiviral protein MxA enhances cell death triggered by endoplasmic reticulum stress.

    PubMed

    Numajiri Haruki, Akiko; Naito, Tadasuke; Nishie, Tomomi; Saito, Shoko; Nagata, Kyosuke

    2011-11-01

    Human myxovirus resistance gene A (MxA) is a type I interferon-inducible protein and exhibits the antiviral activity against a variety of RNA viruses, including influenza virus. Previously, we reported that MxA accelerates cell death of influenza virus-infected cells through caspase-dependent and -independent mechanisms. Similar to other viruses, influenza virus infection induces endoplasmic reticulum (ER) stress, which is one of cell death inducers. Here, we have demonstrated that MxA enhances ER stress signaling in cells infected with influenza virus. ER stress-induced events, such as expression of BiP mRNA and processing of XBP1 mRNA, were upregulated in cells expressing MxA by treatment with an ER stress inducer, tunicamycin (TM), as well as influenza virus infection. TM-induced cell death was also accelerated by MxA. Furthermore, we showed that MxA interacts with BiP and overexpression of BiP reduces MxA-promoted ER stress signaling. Because cell death in virus-infected cells is one of ultimate anti-virus mechanisms, we propose that MxA-enhanced ER stress signaling is a part of the antiviral activity of MxA by accelerating cell death. PMID:21992152

  13. Critical role of phospholipase A2 group IID in age-related susceptibility to severe acute respiratory syndrome–CoV infection

    PubMed Central

    Vijay, Rahul; Hua, Xiaoyang; Meyerholz, David K.; Miki, Yoshimi; Yamamoto, Kei; Gelb, Michael; Murakami, Makoto

    2015-01-01

    Oxidative stress and chronic low-grade inflammation in the lungs are associated with aging and may contribute to age-related immune dysfunction. To maintain lung homeostasis, chronic inflammation is countered by enhanced expression of proresolving/antiinflammatory factors. Here, we show that age-dependent increases of one such factor in the lungs, a phospholipase A2 (PLA2) group IID (PLA2G2D) with antiinflammatory properties, contributed to worse outcomes in mice infected with severe acute respiratory syndrome-coronavirus (SARS-CoV). Strikingly, infection of mice lacking PLA2G2D expression (Pla2g2d−/− mice) converted a uniformly lethal infection to a nonlethal one (>80% survival), subsequent to development of enhanced respiratory DC migration to the draining lymph nodes, augmented antivirus T cell responses, and diminished lung damage. We also observed similar effects in influenza A virus–infected middle-aged Pla2g2d−/− mice. Furthermore, oxidative stress, probably via lipid peroxidation, was found to induce PLA2G2D expression in mice and in human monocyte–derived macrophages. Thus, our results suggest that directed inhibition of a single inducible phospholipase, PLA2G2D, in the lungs of older patients with severe respiratory infections is potentially an attractive therapeutic intervention to restore immune function. PMID:26392224

  14. The functional roles of lipid rafts in T cell activation, immune diseases and HIV infection and prevention.

    PubMed

    Luo, Cheng; Wang, Kou; Liu, De Quan; Li, Yan; Zhao, Qin Shi

    2008-02-01

    The first appearance of lipid rafts, or lipid rafts-like structure, was occasionally observed by cryo-electronic microscopy in 1980s as cavity, such as caveolae. However, the fully understanding of lipid raft was attributed by the studies of T cell activation, virus entry/budding, and other membrane events. During the interaction of T cell and antigen presenting cell, a highly organized structure is formed at the interface of the two cells, where cholesterol and sphingolipids are enriched, and form a liquid ordered phase that facilitates the signaling proteins on and off. Lipid rafts are also involved in virus entry and assembly. In this review, we will discuss cholesterol-sphingolipid floating microdomain, the lipid raft as a unique compartment of the plasma membrane, with biological functions that ensure correct intracellular traffic of proteins and lipids, such as protein-protein interactions by concentrating certain proteins in these microdomains, while excluding others. We also discuss the disruption of lipid rafts is related to different diseases and aging, and we especially exploit the lipid rafts as pharmaceutical targets for anti-virus and anti-inflammation, particularly a new approach to control HIV infection for AIDS prevention and protection by inhibition or disruption of lipid rafts. PMID:18318989

  15. DROP: Detecting Return-Oriented Programming Malicious Code

    NASA Astrophysics Data System (ADS)

    Chen, Ping; Xiao, Hai; Shen, Xiaobin; Yin, Xinchun; Mao, Bing; Xie, Li

    Return-Oriented Programming (ROP) is a new technique that helps the attacker construct malicious code mounted on x86/SPARC executables without any function call at all. Such technique makes the ROP malicious code contain no instruction, which is different from existing attacks. Moreover, it hides the malicious code in benign code. Thus, it circumvents the approaches that prevent control flow diversion outside legitimate regions (such as W ⊕ X ) and most malicious code scanning techniques (such as anti-virus scanners). However, ROP has its own intrinsic feature which is different from normal program design: (1) uses short instruction sequence ending in "ret", which is called gadget, and (2) executes the gadgets contiguously in specific memory space, such as standard GNU libc. Based on the features of the ROP malicious code, in this paper, we present a tool DROP, which is focused on dynamically detecting ROP malicious code. Preliminary experimental results show that DROP can efficiently detect ROP malicious code, and have no false positives and negatives.

  16. The need for culture collections to support plant pathogen diagnostic networks.

    PubMed

    Barba, Marina; Van den Bergh, Inge; Belisario, Alessandra; Beed, Fen

    2010-01-01

    Plant-pathogenic microorganisms, by virtue of their size, similarity in disease symptoms and closely related morphologies, are notoriously difficult to diagnose and detect. Diagnosis gives proof as to the causal agent of disease and is important for developing appropriate control measures. Detection shows the presence of a microorganism and is of importance for safeguarding national and international trade. Live reference collections are required to characterize the taxonomy and function of microorganisms as a prerequisite to development of tools for diagnosis and detection. Two case studies will be presented in this paper to demonstrate the importance of microorganism collections for facilitating knowledge sharing and the development of identification methods. Fusarium wilt of banana caused by Fusarium oxysporum f. sp. cubense and sharka disease of stone fruits caused by plum pox virus (PPV) are considered. Both diseases consist of different races/strains with different host specificities, but Fusarium wilt poses a threat to food security, while PPV poses a threat to trade due to its classification as a quarantine pest, since there is no anti-virus treatment available to control sharka disease in orchards. It is only through comprehensive collections of correctly identified and well-maintained strains representing the genetic diversity of a target organism that robust, specific, reliable and efficient diagnostic and detection tools can be developed. PMID:20457251

  17. Bortezomib as the sole post-renal transplantation desensitization agent does not decrease donor-specific anti-HLA antibodies.

    PubMed

    Sberro-Soussan, R; Zuber, J; Suberbielle-Boissel, C; Candon, S; Martinez, F; Snanoudj, R; Rabant, M; Pallet, N; Nochy, D; Anglicheau, D; Leruez, M; Loupy, A; Thervet, E; Hermine, O; Legendre, C

    2010-03-01

    Persistence of donor-specific anti-HLA antibodies (DSA) associated with antibody-mediated graft injuries following kidney transplantation predicts evolution toward chronic humoral rejection and reduced graft survival. Targeting plasma cells, the main antibody-producing cells, with the proteasome inhibitor bortezomib may be a promising desensitization strategy. We evaluated the in vivo efficacy of one cycle of bortezomib (1.3 mg/m(2)x 4 doses), used as the sole desensitization therapy, in four renal transplant recipients experiencing subacute antibody-mediated rejection with persisting DSA (>2000 [Mean Fluorescence Intensity] MFI). Bortezomib treatment did not significantly decrease DSA MFI within the 150-day posttreatment period in any patient. In addition, antivirus (HBV, VZV and HSV) antibody levels remained stable following treatment suggesting a lack of efficacy on long-lived plasma cells. In conclusion, one cycle of bortezomib alone does not decrease DSA levels in sensitized kidney transplant recipients in the time period studied. These results underscore the need to evaluate this new desensitization agent properly in prospective, randomized and well-controlled studies. PMID:20121729

  18. Saikosaponin-d Enhances the Anticancer Potency of TNF-α via Overcoming Its Undesirable Response of Activating NF-Kappa B Signalling in Cancer Cells.

    PubMed

    Wong, Vincent Kam Wai; Zhang, Molly Miao; Zhou, Hua; Lam, Kelly Yin Ching; Chan, Po Ling; Law, Carmen Ka Man; Yue, Patrick Ying Kit; Liu, Liang

    2013-01-01

    Tumor necrosis factor-alpha (TNF- α ) was reported as anticancer therapy due to its cytotoxic effect against an array of tumor cells. However, its undesirable responses of TNF- α on activating NF- κ B signaling and pro-metastatic property limit its clinical application in treating cancers. Therefore, sensitizing agents capable of overcoming this undesirable effect must be valuable for facilitating the usage of TNF- α -mediated apoptosis therapy for cancer patients. Previously, saikosaponin-d (Ssd), a triterpene saponin derived from the medicinal plant, Bupleurum falcatum L. (Umbelliferae), showed to exhibit a variety of pharmacological activities such as antiinflammation, antibacteria, antivirus and anticancer. Recently, we found that Ssd could inhibit the activated T lymphocytes via suppression of NF- κ B, NF-AT and AP-1 signaling. Here, we showed that Ssd significantly potentiated TNF- α -mediated cell death in HeLa and HepG2 cancer cells via suppression of TNF- α -induced NF- κ B activation and its target genes expression involving cancer cell proliferation, invasion, angiogenesis and survival. Also, Ssd revealed a significant potency of abolishing TNF- α -induced cancer cell invasion and angiogenesis in HUVECs while inducing apoptosis via enhancing the loss of mitochondrial membrane potential in HeLa cells. Collectively, these findings indicate that Ssd has a significant potential to be developed as a combined adjuvant remedy with TNF- α for cancer patients. PMID:23573150

  19. Status of hepatitis C virus vaccination: Recent update

    PubMed Central

    Abdelwahab, Kouka Saadeldin; Ahmed Said, Zeinab Nabil

    2016-01-01

    Hepatitis C virus (HCV) infection is still a major public health problem worldwide since its first identification in 1989. At the start, HCV infection was post-transfusion viral infection, particularly in developing countries. Recently, due to iv drug abuse, HCV infection became number one health problem in well-developed countries as well. Following acute HCV infection, the innate immune response is triggered in the form of activated coordinated interaction of NK cells, dendritic cells and interferon α. The acquired immune response is then developed in the form of the antibody-mediated immune response (ABIR) and the cell-mediated immune response (CMIR). Both are responsible for clearance of HCV infection in about 15% of infected patients. However, HCV has several mechanisms to evade these antivirus immune reactions. The current review gives an overview of HCV structure, immune response and viral evasion mechanisms. It also evaluates the available preventive and therapeutic vaccines that induce innate, ABIR, CMIR. Moreover, this review highlights the progress in recent HCV vaccination studies either in preclinical or clinical phases. The unsatisfactory identification of HCV infection by the current screening system and the limitations of currently available treatments, including the ineligibility of some chronic HCV patients to such antiviral agents, mandate the development of an effective HCV vaccine. PMID:26811632

  20. A virus spreading model for cognitive radio networks

    NASA Astrophysics Data System (ADS)

    Hou, L.; Yeung, K. H.; Wong, K. Y.

    2012-12-01

    Since cognitive radio (CR) networks could solve the spectrum scarcity problem, they have drawn much research in recent years. Artificial intelligence(AI) is introduced into CRs to learn from and adapt to their environment. Nonetheless, AI brings in a new kind of attacks specific to CR networks. The most powerful one is a self-propagating AI virus. And no spreading properties specific to this virus have been reported in the literature. To fill this research gap, we propose a virus spreading model of an AI virus by considering the characteristics of CR networks and the behavior of CR users. Several important observations are made from the simulation results based on the model. Firstly, the time taken to infect the whole network increases exponentially with the network size. Based on this result, CR network designers could calculate the optimal network size to slow down AI virus propagation rate. Secondly, the anti-virus performance of static networks to an AI virus is better than dynamic networks. Thirdly, if the CR devices with the highest degree are initially infected, the AI virus propagation rate will be increased substantially. Finally, it is also found that in the area with abundant spectrum resource, the AI virus propagation speed increases notably but the variability of the spectrum does not affect the propagation speed much.

  1. Lettuce chlorosis virus P23 Suppresses RNA Silencing and Induces Local Necrosis with Increased Severity at Raised Temperatures.

    PubMed

    Kubota, Kenji; Ng, James C K

    2016-06-01

    RNA silencing functions as an antivirus defense strategy in plants, one that plant viruses counter by producing viral suppressors of RNA silencing (VSRs). VSRs have been identified in three members of the genus Crinivirus but they do not all share identical suppression mechanisms. Here, we used Agrobacterium co-infiltration assays to investigate the suppressor activity of proteins encoded by Lettuce chlorosis virus (LCV). Of 7 LCV proteins (1b, P23, HSP70 homolog, P60, CP, CPm, and P27) tested for the suppression of silencing of green fluorescent protein (GFP) expression in wild-type Nicotiana benthamiana plants, only P23 suppressed the onset of local silencing. Small-interfering (si)RNA accumulation was reduced in leaves co-infiltrated with P23, suggesting that P23 inhibited the accumulation or enhanced the degradation of siRNA. P23 also inhibited the cell-to-cell and systemic movement of RNA silencing in GFP-expressing transgenic N. benthamiana plants. Expression of P23 via agroinfiltration of N. benthamiana leaves induced local necrosis that increased in severity at elevated temperatures, a novelty given that a direct temperature effect on necrosis severity has not been reported for the other crinivirus VSRs. These results further affirm the sophistication of crinivirus VSRs in mediating the evasion of host's antiviral defenses and in symptom modulation. PMID:26828232

  2. Herbal Mouthwash Containing Extracts of Baccharis dracunculifolia as Agent for the Control of Biofilm: Clinical Evaluation in Humans

    PubMed Central

    Leite, Mateus Freire; Tavares, Reisla Cristina; Sato, Sandra; do Nascimento, Glauce Crivelaro; Issa, João Paulo Mardegan

    2015-01-01

    Baccharis dracunculifolia DC (Asteraceae), popularly known as “alecrim-do-campo,” is largely distributed in South America, is shown to exhibit protective actions against gastric ulcers, has anti-inflammatory properties, and is hepatoprotective. Several essential oils obtained from Baccharis species possess biological activities, such as antimicrobial and antivirus activities. This randomized controlled trial evaluated the efficacy of B. dracunculifolia in the reduction of dental biofilm, comparing this natural product with other mouthwashes already known in the dental market. In measuring the time after use of mouthwash (t = 1), there was no difference between products (P = 0.602); that is, subjects in the study had a similar PI after the first use. After one week (t = 2), there was no difference between the four products evaluated (P = 0.674), so, all research individuals completed the study with a similar reduction in dental biofilm between themselves but it was different from initial state (Friedman test). It is possible to conclude that B. dracunculifolia had the same efficiency of the materials used to oral hygiene in reduction of dental plaque and, consequently, prevention of dental caries. Thus, we can consider B. dracunculifolia as a good candidate for new material to be implemented in dental care. PMID:25874255

  3. Phishing for suitable targets in the Netherlands: routine activity theory and phishing victimization.

    PubMed

    Leukfeldt, E Rutger

    2014-08-01

    This article investigates phishing victims, especially the increased or decreased risk of victimization, using data from a cybercrime victim survey in the Netherlands (n=10,316). Routine activity theory provides the theoretical perspective. According to routine activity theory, several factors influence the risk of victimization. A multivariate analysis was conducted to assess which factors actually lead to increased risk of victimization. The model included background and financial data of victims, their Internet activities, and the degree to which they were "digitally accessible" to an offender. The analysis showed that personal background and financial characteristics play no role in phishing victimization. Among eight Internet activities, only "targeted browsing" led to increased risk. As for accessibility, using popular operating systems and web browsers does not lead to greater risk, while having up-to-date antivirus software as a technically capable guardian has no effect. The analysis showed no one, clearly defined group has an increased chance of becoming a victim. Target hardening may help, but opportunities for prevention campaigns aimed at a specific target group or dangerous online activities are limited. Therefore, situational crime prevention will have to come from a different angle. Banks could play the role of capable guardian. PMID:25080013

  4. Locked nucleic acid couples with FokⅠnucleases to target and cleave hepatitis B virus’s gene in vitro.

    PubMed

    Li, Ma; Hongyan, Chen; Huaxing, Zhu; Wei, Li; Daru, Lu

    2016-04-01

    Hepatitis B virus (HBV) is a dented double-stranded DNA virus. After infecting human hepatic cells, it forms cccDNA that replicates persistently and integrates randomly into the host’s genome during the process of reserve transcription. On average, in each cell with chronic HBV infection, there are about 33 copies of cccDNA with a half of 35-57 days, which can be difficult to eradicate. A new strategy is to inhibit HBV transcription by using locked nucleic acid (LNA). Besides, cleaving HBV genome by targeted genome editing technologies could potentially cure patients. In this study, we explored new genome editing tools for HBV treatment. Based on LNA’s ability to form triple helix by binding to duplex DNA, its stability towards nuclease and polymerase, and its sensitivity to single base mismatches, we designed LNA-modified oligonucleotides as DNA binding domain to effectively increase the specificity of target gene recognition. Meanwhile, by utilizing the small molecular weight and dimerization dependent activity of nuclease FokⅠ, we used FokⅠrecombinant dimer protein as DNA cleavage domain. Here, we established a method by chemical coupling of LNA-oligonucleotide with FokⅠcleavage domain, and also validated the targeted cleavage of HBV genes with our new tools in vitro. These results provide new possibilities for future in vivo anti-virus gene therapy with high specificity and no integration risk. PMID:27103458

  5. The effects of administration of ligands for Toll-like receptor 4 and 21 against Marek's disease in chickens.

    PubMed

    Parvizi, Payvand; Abdul-Careem, Mohamed Faizal; Mallick, Amirul Islam; Haq, Kamran; Haghighi, Hamid R; Orouji, Shahriar; Heidari, Mohammad; Behboudi, Shahriar; Sharif, Shayan

    2014-04-01

    Ligands for Toll-like receptors (TLRs) are known to stimulate immune responses, leading to protection against bacterial and viral pathogens. Here, we aimed to examine the effects of various TLR ligands on the development of Marek's disease in chickens. Specific-pathogen free chickens were treated with a series of TLR ligands that interact with TLR3, TLR9 and TLR21. In a pilot study, it was determined that TLR4 and TLR21 ligands are efficacious, in that they could reduce the incidence of Marek's disease tumors in infected birds. Hence, in a subsequent study, chickens were treated with lipopolysaccharide (LPS) as a TLR4 and CpG oligodeoxynucleotides (ODN) as TLR21 agonists before being challenged with the RB1B strain of Marek's disease virus (MDV) via the respiratory route. The results demonstrated that the administration of LPS or CpG ODN, but not PBS or non-CpG ODN, delayed disease onset and reduced MDV genome copy number in the spleens of infected chickens. Taken together, our data demonstrate that TLR4 and 21 agonists modulate anti-virus innate immunity including cytokine responses in MD-infected chicken and this response can only delay, but not inhibit, disease progression. PMID:24530927

  6. Angel of human health: current research updates in toad medicine.

    PubMed

    Yang, Qian; Zhou, Xuanxuan; Zhang, Meng; Bi, Linlin; Miao, Shan; Cao, Wei; Xie, Yanhua; Sun, Jiyuan; Tang, Haifeng; Li, Ying; Miao, Qing; Wang, Siwang

    2015-01-01

    There are currently 34 genera and 410 species of toads in the world. The medicinal parts of toads mainly include their venom, skin, and clothing. The toad's venom and skin possess the same chemical components, mainly the toad venom lactone class, and their pharmacological effects primarily include the maintenance of strong heart, antitumor, antivirus, anti-infection, and analgesic effects. So far, the produces from the medicinal raw materials of the toad are widely used clinically around the world, especially in China, Japan, and South Korea. About 50 varieties of medicines are used in the clinical treatment of various complicated diseases in China, such as "Liushen pills" which was popular in the whole world. Toads are mainly used in treating malignant tumors (e.g., liver cancer, gastric cancer, esophageal cancer, colon cancer, cervical cancer, among others), and some major diseases such as hepatitis B. Despite the therapeutic effects of toad-derived medicines on human health, there is insufficient research and development of toad-derived medicines by leading drug companies. In order to harness the beneficial effects of the resources of the toad species, it is the responsibility of global pharmaceutical researchers to develop and generate economically feasible toad-derived therapeutic products, while promoting maximum protection to the resources of the toad species. PMID:25755824

  7. Dimeric Sesquiterpenoids.

    PubMed

    Liao, Shang-Gao; Yue, Jian-Min

    2016-01-01

    It is widely accepted that a large number of proteins that are responsible for cellular function exist as dimers or need to be activated by dimerization before mediating certain signaling pathways. Simultaneously targeting both monomeric moieties of the dimeric proteins has shown potential in the development of various therapeutic agents. As dimeric molecules might be able to act on both moieties of a dimeric protein, dimeric sesquiterpenoids (DSs), which are generated biogenetically from coupling of two sesquiterpenoid molecules, are in essence potential biologically active molecules, and have attracted in recent years great attention for their peculiar structures and biological activities. In fact, a number of DSs are more potent than their monomeric precursors for some activities such as anti-inflammatory, anti-tumor, immunosuppressive, potassium channel blocking, antimalarial, anti-virus, and neurotrophic activities.The complex and diversified structures of DSs also attracted attention of chemists in their isolation, structural elucidation, and synthetic construction.In the contribution, a general view of the classification and distribution of DSs will be provided. Strategies for the structural elucidation of DSs and their analogues is presented. Chemical strategies for the convergence of the two sesquiterpenoid units is reviewed. Biological activities are discussed under each type of activity. PMID:26659108

  8. Suppressive Effects of the Site 1 Protease (S1P) Inhibitor, PF-429242, on Dengue Virus Propagation.

    PubMed

    Uchida, Leo; Urata, Shuzo; Ulanday, Gianne Eduard L; Takamatsu, Yuki; Yasuda, Jiro; Morita, Kouichi; Hayasaka, Daisuke

    2016-01-01

    Dengue virus (DENV) infection causes one of the most widespread mosquito-borne diseases in the world. Despite the great need, effective vaccines and practical antiviral therapies are still under development. Intracellular lipid levels are regulated by sterol regulatory elements-binding proteins (SREBPs), which are activated by serine protease, site 1 protease (S1P). Small compound PF-429242 is known as a S1P inhibitor and the antivirus effects have been reported in some viruses. In this study, we examined the anti-DENV effects of PF-429242 using all four serotypes of DENV by several primate-derived cell lines. Moreover, emergence of drug-resistant DENV mutants was assessed by sequential passages with the drug. DENV dependency on intracellular lipids during their infection was also evaluated by adding extracellular lipids. The addition of PF-429242 showed suppression of viral propagation in all DENV serotypes. We showed that drug-resistant DENV mutants are unlikely to emerge after five times sequential passages through treatment with PF-429242. Although the levels of intracellular cholesterol and lipid droplets were reduced by PF-429242, viral propagations were not recovered by addition of exogenous cholesterol or fatty acids, indicating that the reduction of LD and cholesterol caused by PF-429242 treatment is not related to its mechanism of action against DENV propagation. Our results suggest that PF-429242 is a promising candidate for an anti-DENV agent. PMID:26875984

  9. Preparative isolation and purification of lignans from Justicia procumbens using high-speed counter-current chromatography in stepwise elution mode.

    PubMed

    Zhou, Peijuan; Luo, Qijun; Ding, Lijian; Fang, Fang; Yuan, Ye; Chen, Juanjuan; Zhang, Jinrong; Jin, Haixiao; He, Shan

    2015-01-01

    Lignans, which are recognized as main constituents in Justicia procumbens, have attracted considerable attention due to their pharmacological activities, including antitumor, anti-hepatitic, cytotoxic, anti-microbial, and anti-virus properties. Preparative high-speed counter-current chromatography (HSCCC) was successfully applied to the isolation and purification of four lignans (justicidin B (1), justicidin A (2), 6'-hydroxyjusticidin C (3) and lignan J1 (4)) from J. procumbens using stepwise elution with a pair of two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water at (1.3:1:1.3:1, v/v) and (2.5:1:2.5:1, v/v). The preparative HSCCC separation was performed on 300 mg of crude sample yielding compounds 1 (19.7 mg), 2 (9.86 mg), 3 (11.26 mg), and 4 (2.54 mg) in a one-step separation, with purities over 95% as determined by HPLC. The structures of these compounds were identified by MS, 1H-NMR and 13C-NMR. This is the first report on the application of HSCCC to the efficient separation of lignans from J. procumbens. PMID:25903362

  10. Rice Responses and Resistance to Planthopper-Borne Viruses at Transcriptomic and Proteomic Levels.

    PubMed

    Cui, Feng; Zhao, Wan; Luo, Lan; Kang, Le

    2016-01-01

    Rice (Oryza sativa) is one of the most important cereal crops in the world, especially in Asian areas. Rice virus diseases are considered as the most serious threat to rice yields. Most rice viruses are transmitted by hemipteran insects such as planthoppers and leafhoppers. In Asia five rice viruses are transmitted mainly by three planthopper species in a persistent manner: Rice stripe virus, Rice black-streaked dwarf virus, Rice ragged stunt virus, Rice grassy stunt virus, and Southern rice black-streaked dwarf virus. In rice antivirus studies, several individual genes have been shown to function in rice resistance to viruses. Since plant responses to viral infection are complex, system-level omic studies are required to fully understand the responses. Recently more and more omic studies have appeared in the literatures on relationships between planthoppers and viruses, employing microarray, RNA-Seq, small RNA deep sequencing, degradome sequencing, and proteomic analysis. In this paper, we review the current knowledge and progress of omic studies in rice plant responses and resistance to four planthopper-borned viruses. We also discuss progress in the omic study of the interactions of planthoppers and rice viruses. Future research directions and translational applications of fundamental knowledge of virus-vector-rice interactions are proposed. PMID:26363817

  11. Increased hydroxymethylglutaryl coenzyme A reductase activity during respiratory syncytial virus infection mediates actin dependent inter-cellular virus transmission.

    PubMed

    Ravi, Laxmi Iyer; Liang, Li; Wong, Pui San; Brown, Gaie; Tan, Boon Huan; Sugrue, Richard J

    2013-10-01

    We have examined the role that hydroxymethylglutaryl coenzyme A reductase (HMGCR) plays during respiratory syncytial virus (RSV) maturation. Imaging analysis indicated that virus-induced changes in F-actin structure correlated with the formation of virus filaments, and that these virus filaments played a direct role in virus cell-to-cell transmission. Treatment with cytochalasin D (CYD) prevented virus filament formation and virus transmission, but this could be reversed by removal of CYD. This observation, together with the presence of F-actin within the virus filaments suggested that newly polymerised F-actin was required for virus transmission. The virus-induced change in F-actin was inhibited by the HMGCR inhibitor lovastatin, and this correlated with the inhibition of both virus filament formation and the incorporation of F-actin in these virus structures. Furthermore, this inhibitory effect on virus filament formation correlated with a significant reduction in RSV transmission. Collectively these data suggested that HMGCR-mediated changes in F-actin structure play an important role in the inter-cellular transmission of mature RSV particles. These data also highlighted the interplay between cellular metabolism and RSV transmission, and demonstrate that this interaction can be targeted using anti-virus strategies. PMID:23994498

  12. A Drosophila ABC transporter regulates lifespan.

    PubMed

    Huang, He; Lu-Bo, Ying; Haddad, Gabriel G

    2014-12-01

    MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling. PMID:25474322

  13. Self-Programmed Counseling and Self-Programmed Control Manual. A Guide to Self-Image Development with Emphasis on the Chicano Student. Student's Guide = Manual de Sistema de Consejo Auto Programado y Control Auto Programado. Una Guia Para el Desarrollo de La Imagen Propia Con un Enfasis en el Estudiante Chicano.

    ERIC Educational Resources Information Center

    Mireles, S. Raymond

    Self-Programmed Counseling, the instructor's guidance, and Self-Programmed Control (SPC), the student's response, was initially developed by Title III Project USTED (United Students and Teachers for Educational Development) for Mexican American college students on academic probation to use on a non-credit, special group counseling basis. As part…

  14. Comparing Teaching Styles and Personality Types of EFL Instructors in the Public and Private Sectors (Una comparación de los estilos de enseñanza y los tipos de personalidad de profesores de inglés de los sistemas educativos estatal y privado)

    ERIC Educational Resources Information Center

    Diaz Larenas, Claudio H.; Rodriguez Moran, Andrea Victoria; Poblete Rivera, Karen Jocelyn

    2011-01-01

    This is an exploratory non-experimental research study whose main objective is to compare the teaching styles of a group of thirty teachers of English working in either public or private secondary education in Chile. In order to collect the required data, two instruments were administered to the participants: a teaching style inventory and a…

  15. Self-Programmed Counseling and Self-Programmed Control Manual. A Guide to Self-Image Development with Emphasis on the Chicano Student. Student's Guide = Manual de Sistema de Consejo Auto Programado y Control Auto Programado. Una Guia Para el Desarrollo de La Imagen Propia Con un Enfasis en el Estudiante Chicano.

    ERIC Educational Resources Information Center

    Mireles, S. Raymond

    Self-Programmed Counseling, the instructor's guidance, and Self-Programmed Control (SPC), the student's response, was initially developed by Title III Project USTED (United Students and Teachers for Educational Development) for Mexican American college students on academic probation to use on a non-credit, special group counseling basis. As part…

  16. Para Candidatos en Programas de Centros de Cuidado y Educacion Infantil con Bebes y "Toddlers": Asociado en Desarrollo Infantil Sistema de Evaluacion y Normas de Competencia CDA (Infant/Toddler Caregivers in Center-Based Programs: The Child Development Associate Assessment System and Competency Standards).

    ERIC Educational Resources Information Center

    Council for Early Childhood Professional Recognition, Washington, DC.

    This Spanish-language booklet outlines the requirements of the Child Development Associate (CDA) credential for caregivers working in center-based infant and toddler day care programs. Part 1 provides an overview of the CDA credentialing system and the various options, settings, standards, and stages of the CDA assessment system. Part 2 explains…

  17. Para Candidatos en Programas de Centros de Cuidado y Educacion Infantil con Ninos de Edad Pre-escolar: Asociado en Desarrollo Infantil Sistema de Evaluacion y Normas de Competencia CDA (Preschool Caregivers in Center-Based Programs: The Child Development Associate Assessment System and Competency Standards).

    ERIC Educational Resources Information Center

    Council for Early Childhood Professional Recognition, Washington, DC.

    This Spanish-language booklet outlines the requirements of the Child Development Associate (CDA) credential for preschool teachers or caregivers who work in center-based preschool day care programs. Part 1 provides an overview of the CDA credentialing system and the various options, settings, standards, and stages of the CDA assessment system.…

  18. [In Process Citation].

    PubMed

    Molina Recio, Guillermo; Moreno Rojas, Rafael; García Rodríguez, María; Vaquero Abellán, Manuel

    2016-01-01

    Introducción: un gran número de encuestas nutricionales en Perú han identificado la magnitud y la ubicación de los diferentes tipos de desnutrición, siendo la forma crónica la más prevalente. Sin embargo, aunque las tasas pueden considerarse alarmantes (aún más en las zonas rurales), sólo un trabajo contiene información sobre las características de la ingesta, usando recordatorios de 24 horas (R24). Es decir, se carece de otros sistemas de estudio centrados en conocer las características gastronómicas de sus regiones y la biodisponibilidad de los alimentos, con el fin de localizar el origen de esta situación en cada área y proponer soluciones verdaderamente eficaces y eficientes.Objetivo: determinar el valor nutricional de los platos principales consumidos por los residentes de un barrio pobre de la Amazonía Peruana, para identificar las causas de la pérdida de un estado nutricional saludable.Métodos: noventa y ocho participantes completaron tres R24. Basándonos en estos datos, se seleccionaron los 25 platos más comúnmente consumidos y evaluamos su composición nutricional. Tomamos nota de las recetas, pesos y medidas caseras. Además, se observó la preparación y cocción. La composición nutricional media de cada plato se calculó por 100 g utilizando el software Nutriplato 4.6. También se calcularon lasganancias o pérdidas derivadas de los tratamientos culinarios.Resultados: dentro de los platos basados en la leche, el de más alta densidad de energía es el mingado de arroz. En el grupo de los pescados, la mayor cantidad de energía es aportada por el pescado frito, mientras que en las recetas a base de carne, las más energéticas son el tallarín con pollo, la res asada y el cerdo frito. Como platos preparados, el juane tiene la más alta densidad de energía de todas las recetas. Dentro de las guarniciones, aquellas que utilizan los plátanos como el ingrediente principal, el plátano frito y el madurito, son las más energéticas. Las grasas son más elevadas en los platos fritos y son estos platos los que más contribuyen al porcentaje total de grasa consumida. Lo mismo ocurre en las guarniciones, donde 100 g de plátano frito o madurito contienen más del 70% de la dosis diaria recomendada. La res asada y el juane tienen el nivel más alto de sodio.Conclusiones: si se desea ofrecer platos más saludables, es necesario cambiar algunos hábitos alimenticios, lo que supone reducir el consumo de alimentos fritos porque probablemente está relacionado con la obesidad y otras enfermedades crónicas cardiovasculares. También se debe reducir la ingesta de sodio. Dos alimentos que podrían ser importantes son la menudencia de pollo, rica en vitaminas del grupo B y baja en grasas, y el frijol hervido, rico en proteínas vegetales, que con platos de arroz, omnipresentes en esta área, incrementaría el valor biológico de las proteínas ingeridas. PMID:27019248

  19. Medicinal ethnobotany in Huacareta (Chuquisaca, Bolivia)

    PubMed Central

    2012-01-01

    Background The aim of this study was to document the types of diseases treated by the use of medicinal plants, their main applications and also to have a report of the major diseases treated at the Hospital of San Pablo de Huacareta (Chuquisaca Bolivia). Methods We conducted semi-structured interviews on the use medicinal plants with 10 local informants, and categorized the kinds of diseases treated by traditional medicine. We obtained reports of cases treated at the Hospital of Huacareta in order to compare the use frequency of traditional medicine and allopathic medicine for the treatment of recurrent diseases in the area. Results Our survey identified 258 traditional medicine uses, spanning a total of 13 diseases categories and including 91 native and exotic plant species and one unidentified sample plant type. Gastrointestinal disorders (55%) were most frequently treated with medicinal plants, followed by afflictions of the musculoskeletal system (25%) and dermatological disorders (24%). Hospital information indicates that the most common diseases are acute respiratory infections (47%) and acute diarrheal diseases (37%). The herbal remedies were mostly used in the form of teas and decoctions. The informants used mainly native plant species, although exotic species has been introduced to the pharmacopoeia. Conclusions The treatment of gastrointestinal disorders is the primary objective of the medical ethnobotany of the inhabitants of Huacareta, while respiratory system diseases are mostly treated in the hospital. Looking at the data from the Hospital records we can infer that gastrointestinal disorders are among the most common diseases in the study area. For most respondents, traditional medicine is a reliable choice for the care of their illnesses. However, the preference of the population for either traditional medicine or allopathic medicine needs to be clarified in future comparative studies to obtain more convincing results. The results presented can be used as a base for subsequent work related to traditional medicine and its contribution to allopathic medicine in San Pablo de Huacareta. Resumen Introducción El objetivo del presente estudio fue documentar los tipos de enfermedades tratadas mediante el uso de plantas medicinales, sus aplicaciones principales y también tener un reporte de las enfermedades mayormente atendidas en el Hospital de San Pablo de Huacareta (Chuquisaca, Bolivia). Métodos Se realizaron encuestas semiestructuradas a 10 informantes locales anotando los usos atribuidos a sus plantas medicinales, se agruparon las plantas por categorías de enfermedades tratadas en la medicina tradicional. Se obtuvieron reportes de casos tratados en el Hospital de Huacareta para poder relacionar el tratamiento de enfermedades recurrentes en la zona entre la medicina tradicional y la medicina occidental. Resultados Se reportaron 91 especies nativas y exóticas, además de un espécimen indeterminado exótico que intervienen en un total de 258 aplicaciones medicinales, las cuales son empleadas en un total de 13 categorías de enfermedades. Los desórdenes gastrointestinales (55%) son mayormente tratados mediante plantas medicinales, seguidas de las afecciones al sistema esqueleto-muscular (25%) y enfermedades dermatológicas (24%). La información del Hospital indica que las enfermedades más frecuentes son Infecciones Respiratorias Agudas (47%) y Enfermedades Diarreicas Agudas (37%). Los remedios vegetales se emplean en forma de infusiones y cocciones principalmente. Se emplean mayormente plantas nativas, también se introdujo en la farmacopea médica el uso de plantas exóticas al lugar. Conclusiones El tratamiento de trastornos gastrointestinales constituye el objetivo primordial de la etnobotánica médica de los habitantes de Huacareta, las enfermedades del sistema respiratorio, son mayormente tratadas en el Hospital. Observando los datos del libro de consultas del Hospital, se puede inferir que los desórdenes gastrointestinales están entre las enfermedades más frecuentes en el área estudiada. Para la mayoría de los entrevistados, la medicina tradicional es una opción confiable para la atención de sus enfermedades. Sin embargo, la preferencia de los habitantes entre la medicina tradicional y la medicina alopática podría ser clarificada a partir de futuros estudios comparativos que permitan obtener resultados más convincentes. Los resultados expuestos pueden ser usados como una base de datos para posteriores trabajos relacionados a la medicina tradicional y su contribución con la medicina alopática en San Pablo de Huacareta. PMID:22856877

  20. Geostatistical mapping of leakance in a regional aquitard, Oak Ridges Moraine area, Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Desbarats, A. J.; Hinton, M. J.; Logan, C. E.; Sharpe, D. R.

    2001-01-01

    The Newmarket Till forms a regionally extensive aquitard separating two major aquifer systems in the Greater Toronto area, Canada. The till is incised, and sometimes eroded entirely, by a network of sand- and gravel-filled channels forming productive aquifers and, locally, high-conductivity windows between aquifer systems. Leakage through the till may also be substantial in places. This study investigates the spatial variability of aquitard leakance in order to assess the relative importance of recharge processes to the lower aquifers. With a large database derived from water-well records and containing both hard and soft information, the Sequential Indicator Simulation method is used to generate maps of aquitard thickness and window probability. These can be used for targeting channel aquifers and for identifying potential areas of recharge to the lower aquifers. Conductivities are modeled from sparse data assuming that their correlation range is much smaller than the grid spacing. Block-scale leakances are obtained by upscaling nodal values based on simulated conductivity and thickness fields. Under the "aquifer-flow'' assumption, upscaling is performed by arithmetic spatial averaging. Histograms and maps of upscaled leakances show that heterogeneities associated with aquitard windows have the largest effect on regional groundwater flow patterns. Résumé. La moraine glaciaire de Newmarket constitue un imperméable d'extension régionale séparant deux systèmes aquifères dans la région du Grand Toronto (Canada). La moraine est entaillée, et parfois entièrement érodée, par un réseau de chenaux comblés de sables et de graviers formant des aquifères productifs et, localement, des «fenêtres», zones à forte conductivité hydraulique reliant les systèmes aquifères. Une drainance au travers de la moraine peut également être significative par endroits. Cette étude s'intéresse à la variabilité spatiale de la drainance au travers de l'imperméable, dans le but d'évaluer l'importance relative des processus d'alimentation des aquifères inférieurs. À partir d'une vaste base de données constituée par les mesures faites dans les puits et contenant des informations à la fois certaines et incertaines, la méthode de simulation par indicateur séquentiel est utilisée pour créer des cartes d'épaisseur de l'imperméable et de probabilité d'existence des fenêtres. Ces cartes peuvent être utilisées pour mettre en évidence les aquifères de chenaux et pour identifier les zones potentielles de recharge des aquifères inférieurs. Les conductivités hydrauliques sont modélisées à partir de données clairsemées en supposant que leur gamme de corrélation est beaucoup plus faible que le pas de la grille. La drainance à l'échelle des blocs est obtenue par accroissement du niveau d'échelle des valeurs nodales basé sur les champs de conductivité simulée et des épaisseurs. À partir de l'hypothèse d'écoulement dans l'aquifère, l'accroissement d'échelle est réalisé en faisant une moyenne arithmétique spatiale. Des histogrammes et des cartes de drainance avec accroissement d'échelle montrent que les hétérogénéités associées aux fenêtres dans l'imperméable constituent l'effet le plus important dans l'organisation des écoulements souterrains régionaux. Resumen. El Till de Newmarket forma un acuitardo de extensión regional que separa dos sistemas acuíferos principales en la zona de Greater Toronto (Canadá). El till está horadado, y a veces completamente erosionado, por una red de canales rellenos de arena y grava. Estos constituyen acuíferos productivos y, localmente, conexiones de alta permeabilidad entre sistemas acuíferos. El goteo a través del till puede ser fundamental en ciertos lugares. Este estudio investiga la variabilidad espacial del goteo desde el acuitardo con el fin de establecer la importancia relativa de los procesos de recarga hacia los acuíferos inferiores. Se ha utilizado el método de la Simulación Indicadora Secuencial, soportado por una gran base de datos que contiene registros de sondeos e incluye información blanda y dura, para generar mapas de espesor del acuitardo y mapas de probabilidad de discontinuidades laterales en el acuitardo. Estos resultados se pueden emplear para identificar canales y las zonas de recarga potencial a los acuíferos inferiores. Se han modelado las conductividades a partir de datos dispersos, suponiendo que la distancia de correlación es mucho menor que el espaciado de la malla. Se han calculado valores de goteo a escala de bloque por medio del escalado de los valores nodales, basándose en los campos simulados de conductividad y espesor. El escalado se calcula mediante un promedio aritmético espacial, bajo la hipótesis de "flujo en el acuífero". Los histogramas y mapas de goteos escalados muestran que las heterogeneidades asociadas a las discontinuidades en el acuitardo producen el efecto más notable en la distribución regional del flujo de aguas subterráneas.

  1. Approaches to optimal aquifer management and intelligent control in a multiresolutional decision support system

    NASA Astrophysics Data System (ADS)

    Orr, Shlomo; Meystel, Alexander M.

    2005-03-01

    Despite remarkable new developments in stochastic hydrology and adaptations of advanced methods from operations research, stochastic control, and artificial intelligence, solutions of complex real-world problems in hydrogeology have been quite limited. The main reason is the ultimate reliance on first-principle models that lead to complex, distributed-parameter partial differential equations (PDE) on a given scale. While the addition of uncertainty, and hence, stochasticity or randomness has increased insight and highlighted important relationships between uncertainty, reliability, risk, and their effect on the cost function, it has also (a) introduced additional complexity that results in prohibitive computer power even for just a single uncertain/random parameter; and (b) led to the recognition in our inability to assess the full uncertainty even when including all uncertain parameters. A paradigm shift is introduced: an adaptation of new methods of intelligent control that will relax the dependency on rigid, computer-intensive, stochastic PDE, and will shift the emphasis to a goal-oriented, flexible, adaptive, multiresolutional decision support system (MRDS) with strong unsupervised learning (oriented towards anticipation rather than prediction) and highly efficient optimization capability, which could provide the needed solutions of real-world aquifer management problems. The article highlights the links between past developments and future optimization/planning/control of hydrogeologic systems. Malgré de remarquables nouveaux développements en hydrologie stochastique ainsi que de remarquables adaptations de méthodes avancées pour les opérations de recherche, le contrôle stochastique, et l'intelligence artificielle, solutions pour les problèmes complexes en hydrogéologie sont restées assez limitées. La principale raison est l'ultime confiance en les modèles qui conduisent à des équations partielles complexes aux paramètres distribués (PDE) à une échelle donnée. Alors que l'accumulation d'incertitudes et, par conséquent, la stockasticité ou l'aléat a augmenté la perspicacité et amis en lumière d'importantes relations entre l'incertitude, la fiabilité, le risque, et leur effet sur les coûts de fonctionnement, il a également (a) introduit une complexité additionnelle qui résulte dans un pouvoir prohibitif des moyens de calcul informatique même pour une simple estimation de l'incertitude; et (b) a conduita une reconnaissance de notre manque d'aptitude à maîtriser l'incertitude totale même en introduisant tous les paramètres connus de l'incertitude. La représentation du changement est introduit: une adaptation de nouvelles méthodes de contrôle intelligent qui va relâcher la dépendance à la rigidité des algorithmes, aux calculs informatiques intensifs, à la PDE stockastique, et qui modifiera l'emphase entre les MRDS—systèmes interactifs d'aide à la décision de multiresolutionelle (flexibles, adaptables et orientables selon les objectifs)—avec un fort apprentissage non (orienté vers l'anticipation plutôt que la prédiction), et une capacité d'optimisation efficiente très élevée, qui pourrait apporter le besoin de solutions pour la modélisation des problèmes de management des aquifères réalistes. Cet article met en lumière les liens entre les développements passés et les futurs moyens d'optimisation, de gestion et de contrôle des systèmes hydrogéologiques. A pesar de nuevos avances notables en hidrología estocástica y las adaptaciones de métodos avanzados de investigación de operaciones, control estocástico, e inteligencia artificial, las soluciones de problemas complejos del mundo real en hidrogeología han sido bastante limitadas. La principal razón es la dependencia definitiva en modelos de primer-principio que conducen a ecuaciones parciales diferencias de parámetro distribuido complejas (PDE) a una escala dada. Mientras que la adición de incertidumbre, y por lo tanto, estocasticidad o aleatoriedad ha incrementado la profundidad y resaltado relaciones importantes entre la incertidumbre, confiabilidad, riesgo, y su efecto en la función de costo, la adición también ha permitido (a) introducir complejidad adicional que resulta en potencia computacional excesiva aún para un solo parámetro incierto/aleatorio; y (b) llevar a reconocer nuestra discapacidad para evaluar la incertidumbre completa aún cuando se incluyen todos los parámetros inciertos. Se introduce un cambio paradigmático: una adaptación de nuevos métodos de control de inteligencia que relajarála dependencia en PDE estocásticas, rígidas y de uso computacional intensivo, cambiando el énfasis hacia un sistema de apoyo de decisiones de propósitos múltiples (MRDS) adaptivo, flexible, y orientadoa objetivos con fuerte aprendizaje sin supervisión (orientado a la anticipación más que a la predicción) con fuerte capacidad de optimización eficiente, lo cual podría aportar las soluciones necesarias a los problemas de manejo reales con los acuíferos. El artículo resalta los vínculos entre desarrollos pasados y control/planificación/optimización futura de sistemas hidrogeológicos.

  2. Atlas del Genoma del Cáncer: Antecedentes

    Cancer.gov

    El Atlas del Genoma del Cáncer es una iniciativa de los Institutos Nacionales de la Salud (NIH) para crear mapas multidimensionales completos de los cambios genómicos clave en los tipos y subtipos principales de cáncer.

  3. Fistule vesico-sigmoïdienne compliquant une hydatidose intestinale: à propos d'un cas rare

    PubMed Central

    Lahyani, Mounir; Jabbour, Younes; Karmouni, Tarik; Elkhader, Khalid; Koutani, Abdellatif; Andaloussi, Ahmed Ibn attya

    2014-01-01

    La fistule colo-vésicale sur une hydatidose sigmoidienne est une entité pathologique exceptionnelle. Nous rapportions une nouvelle observation, ou seront rappelées les principales données diagnostique et thérapeutique de cette affection. PMID:25722790

  4. Hidrógeno neutro en el Hemisferio Austral

    NASA Astrophysics Data System (ADS)

    Morras, R.

    Se muestran los resultados de la distribución del HI en el cielo austral, obtenidos a partir de los datos de un relevamiento en la línea de 21 cm recientemente concluido en el IAR. Se discuten algunos de los principales problemas que pueden confrontarse con las observaciones de HI de nuestra Galaxia.

  5. Pilot Program to Focus on Performance-Based Teacher Assessments

    ERIC Educational Resources Information Center

    Education Digest: Essential Readings Condensed for Quick Review, 2011

    2011-01-01

    To raise the bar for teacher preparation and evaluation, assessments should be based on how well teachers perform in the classroom, not how they are rated during principal-led classroom observations or on written licensure tests, a new report argues. "Evaluating Teacher Effectiveness," by education policy expert and Stanford professor Linda…

  6. Informe a la Nación de mortalidad por cáncer sigue bajando

    Cancer.gov

    El Informe Anual a la Nación sobre el Estado del Cáncer, de 1975 a 2009, indica que los índices generales de mortalidad por cáncer siguen bajando en los Estados Unidos en hombres y mujeres, entre todos los grupos raciales y étnicos principales y para todo

  7. Comunicado de prensa del Informe Anual sobre el Estado del Cáncer 2015

    Cancer.gov

    Por primera vez, los investigadores han usado datos a nivel nacional para determinar la incidencia de los cuatro subtipos moleculares principales de cáncer de seno (mama) por edad, raza y grupo étnico, nivel de pobreza y varios otros factores. El informe

  8. Shared Responsibility for Teacher Evaluation: A Cross-Site Study of Principals' Experiences in Peer Assistance and Review Programs

    ERIC Educational Resources Information Center

    Munger, Mindy S.

    2012-01-01

    Research shows that traditional, principal-led teacher evaluation in the United States is desperately in need of reform. While principals aspire to be instructional leaders, their attention is spread thin across their vast managerial and instructional leadership responsibilities. For many principals, teacher evaluation falls by the wayside. Peer…

  9. Reproduccion del ganado

    Technology Transfer Automated Retrieval System (TEKTRAN)

    La determination de prenez es una de las principales herramientas de manejo en el Ganado de came. Le habilidad de determiner prenez proporciona al productor un medio de tomar sus decsiones de seleccion y descartarte en momentos decisivos, enfocando los recursos de la operacion en reporductores confi...

  10. A network analysis of the Chinese medicine Lianhua-Qingwen formula to identify its main effective components.

    PubMed

    Wang, Chun-Hua; Zhong, Yi; Zhang, Yan; Liu, Jin-Ping; Wang, Yue-Fei; Jia, Wei-Na; Wang, Guo-Cai; Li, Zheng; Zhu, Yan; Gao, Xiu-Mei

    2016-02-01

    Chinese medicine is known to treat complex diseases with multiple components and multiple targets. However, the main effective components and their related key targets and functions remain to be identified. Herein, a network analysis method was developed to identify the main effective components and key targets of a Chinese medicine, Lianhua-Qingwen Formula (LQF). The LQF is commonly used for the prevention and treatment of viral influenza in China. It is composed of 11 herbs, gypsum and menthol with 61 compounds being identified in our previous work. In this paper, these 61 candidate compounds were used to find their related targets and construct the predicted-target (PT) network. An influenza-related protein-protein interaction (PPI) network was constructed and integrated with the PT network. Then the compound-effective target (CET) network and compound-ineffective target network (CIT) were extracted, respectively. A novel approach was developed to identify effective components by comparing CET and CIT networks. As a result, 15 main effective components were identified along with 61 corresponding targets. 7 of these main effective components were further experimentally validated to have antivirus efficacy in vitro. The main effective component-target (MECT) network was further constructed with main effective components and their key targets. Gene Ontology (GO) analysis of the MECT network predicted key functions such as NO production being modulated by the LQF. Interestingly, five effective components were experimentally tested and exhibited inhibitory effects on NO production in the LPS induced RAW 264.7 cell. In summary, we have developed a novel approach to identify the main effective components in a Chinese medicine LQF and experimentally validated some of the predictions. PMID:26687282

  11. Physicochemical characterization of silver nanoparticles synthesize using Aloe Vera (Aloe barbadensis)

    NASA Astrophysics Data System (ADS)

    Kuponiyi, Abiola; Kassama, Lamin; Kukhtareva, Tatiana

    2014-08-01

    Production of silver nanoparticles (AgNPs) using different biological methods is gaining recognition due to their multiple applications. Although, several physical and chemical methods have been used for the synthesis and stabilizing of AgNPs, yet, a green chemistry method is preferable because it is cost effective and environmentally friendly. The synthesis was done using Aloe Vera (AV) extract because it has chemical compounds such as "Antrokinon" that are known for its antibacterial, antivirus and anticancer properties. We hypothesize that AV extract can produce a stable nanoparticles within the 100 nm range and be biologically active. The biological compounds were extracted from AV skin with water and ethanol which was used as the reduction agent for the synthesis of nanoparticles. The biological extract and AgNO3 were blended and heated to synthesize AgNPs. The reaction process was monitored using UV-Visible spectroscopy. Fourier Transfer Infrared spectroscopy (FTIR) was used for the characterization of biological compounds and their substituent groups before and after the reaction process. Dynamic Light scattering (DLS) method was used to characterize particle size of AgNPs and their biomolecular stability. Results showed that biological compounds such as aliphatic amines, alkenes (=C-H), alkanes (C-H), alcohol (O-H) and unsaturated esters(C-O), which has an average particle size of 109 and 215.8 nm and polydispersity index of 0.451 and 0.375 for ethanol and water extract, respectively. According to TEM measurements the size of AgNPs are in the range 5-20 nm The results suggested that ethanol derived AgNPs contained higher yield of organic compounds, thus has better solubility power than water. Ag NPs can be used to control salmonella in poultry industry.

  12. Baculovirus DNA Replication-Specific Expression Factors Trigger Apoptosis and Shutoff of Host Protein Synthesis during Infection▿

    PubMed Central

    Schultz, Kimberly L. W.; Friesen, Paul D.

    2009-01-01

    Apoptosis is an important antivirus defense. To define the poorly understood pathways by which invertebrates respond to viruses by inducing apoptosis, we have identified replication events that trigger apoptosis in baculovirus-infected cells. We used RNA silencing to ablate factors required for multiplication of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Transfection with double-stranded RNA (dsRNA) complementary to the AcMNPV late expression factors (lefs) that are designated as replicative lefs (lef-1, lef-2, lef-3, lef-11, p143, dnapol, and ie-1/ie-0) blocked virus DNA synthesis and late gene expression in permissive Spodoptera frugiperda cells. dsRNAs specific to designated nonreplicative lefs (lef-8, lef-9, p47, and pp31) blocked late gene expression without affecting virus DNA replication. Thus, both classes of lefs functioned during infection as defined. Silencing the replicative lefs prevented AcMNPV-induced apoptosis of Spodoptera cells, whereas silencing the nonreplicative lefs did not. Thus, the activity of replicative lefs or virus DNA replication is sufficient to trigger apoptosis. Confirming this conclusion, AcMNPV-induced apoptosis was suppressed by silencing the replicative lefs in cells from a divergent species, Drosophila melanogaster. Silencing replicative but not nonreplicative lefs also abrogated AcMNPV-induced shutdown of host protein synthesis, suggesting that virus DNA replication triggers inhibition of host biosynthetic processes and that apoptosis and translational arrest are linked. Our findings suggest that baculovirus DNA replication triggers a host cell response similar to the DNA damage response in vertebrates, which causes translational arrest and apoptosis. Pathways for detecting virus invasion and triggering apoptosis may therefore be conserved between insects and mammals. PMID:19706708

  13. Enhancement of the antibody response to flavivirus B-cell epitopes by using homologous or heterologous T-cell epitopes.

    PubMed Central

    Roehrig, J T; Johnson, A J; Hunt, A R; Beaty, B J; Mathews, J H

    1992-01-01

    We have been investigating the T-helper (Th)-cell response to the flavivirus envelope (E) glycoprotein. In our studies with Murray Valley encephalitis (MVE) virus, we previously identified synthetic peptides capable of priming Th lymphocytes for an in vitro antivirus proliferative response (J. H. Mathews, J. E. Allan, J. T. Roehrig, J. R. Brubaker, and A. R. Hunt, J. Virol. 65:5141-5148, 1991). We have now characterized in vivo Th-cell priming activity of one of these peptides (MVE 17, amino acids 356 to 376) and an analogous peptide derived from the E-glycoprotein sequence of the dengue (DEN) 2, Jamaica strain (DEN 17, amino acids 352 to 368). This DEN peptide also primed the Th-cell compartment in BALB/c mice, as measured by in vitro proliferation and interleukin production. The failure of some MVE and DEN virus synthetic peptides to elicit an antibody response in BALB/c mice could be overcome if a Th-cell epitope-containing peptide was included in the immunization mixture. A more detailed analysis of the structural interactions between Th-cell and B-cell epitope donor peptides revealed that the peptides must be linked to observe the enhanced antibody response. Blockage or deletion of the free cysteine residue on either peptide abrogated the antibody response. The most efficient T-B-cell epitope interaction occurred when the peptides were colinearly synthesized. These Th-cell-stimulating peptides were also functional with the heterologous B-cell epitope-containing peptides. The Th-cell epitope on DEN 17 was more potent than the Th-cell epitope on MVE 17. PMID:1374807

  14. Virus manipulation of cell cycle.

    PubMed

    Nascimento, R; Costa, H; Parkhouse, R M E

    2012-07-01

    Viruses depend on host cell resources for replication and access to those resources may be limited to a particular phase of the cell cycle. Thus manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment. For example, viruses capable of infecting nondividing cells induce S phase in order to activate the host DNA replication machinery and provide the nucleotide triphosphates necessary for viral DNA replication (Flemington in J Virol 75:4475-4481, 2001; Sullivan and Pipas in Microbiol Mol Biol Rev 66:179-202, 2002). Viruses have developed several strategies to subvert the cell cycle by association with cyclin and cyclin-dependent kinase complexes and molecules that regulate their activity. Viruses tend to act on cellular proteins involved in a network of interactions in a way that minimal protein-protein interactions lead to a major effect. The complex and interactive nature of intracellular signaling pathways controlling cell division affords many opportunities for virus manipulation strategies. Taking the maxim "Set a thief to catch a thief" as a counter strategy, however, provides us with the very same virus evasion strategies as "ready-made tools" for the development of novel antivirus therapeutics. The most obvious are attenuated virus vaccines with critical evasion genes deleted. Similarly, vaccines against viruses causing cancer are now being successfully developed. Finally, as viruses have been playing chess with our cell biology and immune responses for millions of years, the study of their evasion strategies will also undoubtedly reveal new control mechanisms and their corresponding cellular intracellular signaling pathways. PMID:21986922

  15. Therapeutic approaches to the treatment of recurrent respiratory papillomatosis of the aerodigestive tract (a clinical study)

    PubMed Central

    Avramov, Toma; Vetckova, Evelina; Nikolova, Maria; Valev, Dinko; Manolova, Antoaneta; Tafradgiiska, Maya; Kostadinov, Dimitar; Tchalacov, Ivan

    2014-01-01

    Recurrent respiratory papillomatosis (RRP) is a rare disease, characterized by recurrent proliferation of benign squamous cell papillomas in the larynx as well as in the other parts of the aerodigestive tract. We have compared different treatment options for RRP of the aerodigestive tract including surgical, conservative and combined approaches. A total of 43 patients with papillomatosis that received a combined therapy were followed in the period from 2009 to 2013. The treatment included electrosurgery and CO2 laser surgery alongside with either immunotherapy with Bacillus Calmette-Guerin (BCG) (Calgevax) or α-interferon. In the control group without immunotherapy (n = 16) we used conventional microlaryngeal surgery. During the follow-up, relapse occurred in two patients for the CO2 laser surgery with Calgevax immunotherapy group (n = 16). In the group treated with α-interferon preceded by CO2 laser surgery (n = 9) and electrosurgery (n = 2), relapse had occurred in three patients. Among the control group, recurrence was observed in six patients. This required re-operation. Our data showed a three times more frequent relapses among patients who were operated with conventional surgery as compared to those operated with CO2 laser surgery and Calgevax immunotherapy, and two times more often relapses in patients operated with conventional surgery as compared to those with electrosurgery and CO2 laser surgery and application of α-interferon therapy. Conventional and laser surgeries have a palliative effect, though playing an important role in ensuring the airway patency. While specific antivirus treatment for human papilloma viruses does not exist, the immune modulation with Calgevax considerably reduces the frequency of relapses, by stimulating cellular immune effector mechanisms. The combined protocol allows rarefication of relapses and improvement of patients’ quality of life, but not complete healing. PMID:26692782

  16. Evaluation of Camellia sinensis Catechins as a Swine Antimicrobial Feed Additive that does not Cause Antibiotic Resistance

    PubMed Central

    Ohno, Akira; Kataoka, Shinichiro; Ishii, Yoshikazu; Terasaki, Toshiaki; Kiso, Masaaki; Okubo, Mitsuyuki; Yamaguchi, Keizo; Tateda, Kazuhiro

    2013-01-01

    Antimicrobial growth promoters (AGPs) have been banned and phased out because their use has been linked to the emergence and spread of antibiotic-resistant pathogens; however, the ban has had a marked impact on livestock production, and feed additive alternatives to AGPs are required. We focused on green tea leaves as potential alternatives to AGPs because they contain significant amounts of polyphenol catechins, which have antivirus and antimicrobial effects. We examined cross-resistance between epigallocatechin gallate (EGCG), which is the most abundant catechin of green tea leaves, and commercially available antimicrobials in clinically problematic antimicrobial-resistant bacteria, and whether bacteria have the ability to acquire resistance by consecutive passage in sub-inhibitory concentrations of EGCG. EGCG did not display any cross-resistance with reference antimicrobials and the bacteria did not acquire EGCG resistance. Further, we examined the growth-promoting effects of dried green tea leaves on the breeding of a new Japanese breed, Tokyo-X pigs. While the mortality rates of the green tea leaf (GTL) and AGP groups were both 11.1% (one in nine piglets), the mortality rate was 50% for the control group with an additive-free diet (four in eight piglets). The rate of body weight increase in both the GTL and AGP groups was approximately the same. The growth-promoting effects of green tea leaves and AGPs were similar, and there was no possibility that the antimicrobial properties of catechins caused the same problem as AGPs. Thus, it can be concluded that green tea leaves are a safe feed additive alternative to AGPs. PMID:23138151

  17. Targeting N-Glycan Cryptic Sugar Moieties for Broad-Spectrum Virus Neutralization: Progress in Identifying Conserved Molecular Targets in Viruses of Distinct Phylogenetic Origins

    PubMed Central

    Wang, Denong; Tang, Jin; Tang, Jiulai; Wang, Lai-Xi

    2015-01-01

    Identifying molecular targets for eliciting broadly virus-neutralizing antibodies is one of the key steps toward development of vaccines against emerging viral pathogens. Owing to genomic and somatic diversities among viral species, identifying protein targets for broad-spectrum virus neutralization is highly challenging even for the same virus, such as HIV-1. However, viruses rely on host glycosylation machineries to synthesize and express glycans and, thereby, may display common carbohydrate moieties. Thus, exploring glycan-binding profiles of broad-spectrum virus-neutralizing agents may provide key information to uncover the carbohydrate-based virus-neutralizing epitopes. In this study, we characterized two broadly HIV-neutralizing agents, human monoclonal antibody 2G12 and Galanthus nivalis lectin (GNA), for their viral targeting activities. Although these agents were known to be specific for oligomannosyl antigens, they differ strikingly in virus-binding activities. The former is HIV-1 specific; the latter is broadly reactive and is able to neutralize viruses of distinct phylogenetic origins, such as HIV-1, severe acute respiratory syndrome coronavirus (SARS-CoV), and human cytomegalovirus (HCMV). In carbohydrate microarray analyses, we explored the molecular basis underlying the striking differences in the spectrum of anti-virus activities of the two probes. Unlike 2G12, which is strictly specific for the high-density Man9GlcNAc2Asn (Man9)-clusters, GNA recognizes a number of N-glycan cryptic sugar moieties. These include not only the known oligomannosyl antigens but also previously unrecognized tri-antennary or multi-valent GlcNAc-terminating N-glycan epitopes (Tri/m-Gn). These findings highlight the potential of N-glycan cryptic sugar moieties as conserved targets for broad-spectrum virus neutralization and suggest the GNA-model of glycan-binding warrants focused investigation. PMID:25774492

  18. Evolution of microbes and viruses: a paradigm shift in evolutionary biology?

    PubMed Central

    Koonin, Eugene V.; Wolf, Yuri I.

    2012-01-01

    When Charles Darwin formulated the central principles of evolutionary biology in the Origin of Species in 1859 and the architects of the Modern Synthesis integrated these principles with population genetics almost a century later, the principal if not the sole objects of evolutionary biology were multicellular eukaryotes, primarily animals and plants. Before the advent of efficient gene sequencing, all attempts to extend evolutionary studies to bacteria have been futile. Sequencing of the rRNA genes in thousands of microbes allowed the construction of the three- domain “ribosomal Tree of Life” that was widely thought to have resolved the evolutionary relationships between the cellular life forms. However, subsequent massive sequencing of numerous, complete microbial genomes revealed novel evolutionary phenomena, the most fundamental of these being: (1) pervasive horizontal gene transfer (HGT), in large part mediated by viruses and plasmids, that shapes the genomes of archaea and bacteria and call for a radical revision (if not abandonment) of the Tree of Life concept, (2) Lamarckian-type inheritance that appears to be critical for antivirus defense and other forms of adaptation in prokaryotes, and (3) evolution of evolvability, i.e., dedicated mechanisms for evolution such as vehicles for HGT and stress-induced mutagenesis systems. In the non-cellular part of the microbial world, phylogenomics and metagenomics of viruses and related selfish genetic elements revealed enormous genetic and molecular diversity and extremely high abundance of viruses that come across as the dominant biological entities on earth. Furthermore, the perennial arms race between viruses and their hosts is one of the defining factors of evolution. Thus, microbial phylogenomics adds new dimensions to the fundamental picture of evolution even as the principle of descent with modification discovered by Darwin and the laws of population genetics remain at the core of evolutionary biology. PMID:22993722

  19. Ascophyllan purified from Ascophyllum nodosum induces Th1 and Tc1 immune responses by promoting dendritic cell maturation.

    PubMed

    Zhang, Wei; Du, Jiang-Yuan; Jiang, Zedong; Okimura, Takasi; Oda, Tatsuya; Yu, Qing; Jin, Jun-O

    2014-07-01

    Marine-derived sulfated polysaccharides have been shown to possess certain anti-virus, anti-tumor, anti-inflammatory and anti-coagulant activities. However, the in vivo immunomodulatory effects of marine-derived pure compounds have been less well characterized. In this study, we investigated the effect of ascophyllan, a sulfated polysaccharide purified from Ascophyllum nodosum, on the maturation of mouse dendritic cells (DCs) in vitro and in vivo. Ascophyllan induced up-regulation of co-stimulatory molecules and production of pro-inflammatory cytokines in bone marrow-derived DCs (BMDCs). Moreover, in vivo administration of ascophyllan promotes up-regulation of CD40, CD80, CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen cDCs. Interestingly, ascophyllan induced a higher degree of co-stimulatory molecule up-regulation and pro-inflammatory cytokine production than fucoidan, a marine-derived polysaccharide with well-defined effect for promoting DC maturation. Ascophyllan also promoted the generation of IFN-γ-producing Th1 and Tc1 cells in the presence of DCs in an IL-12-dependent manner. Finally, myeloid differentiation primary response 88 (MyD88) signaling pathway was essential for DC maturation induced by ascophyllan. Taken together, these results demonstrate that ascophyllan induces DC maturation, and consequently enhances Th1 and Tc1 responses in vivo. This knowledge could facilitate the development of novel therapeutic strategies to combat infectious diseases and cancer. PMID:25026264

  20. Ascophyllan Purified from Ascophyllum nodosum Induces Th1 and Tc1 Immune Responses by Promoting Dendritic Cell Maturation

    PubMed Central

    Zhang, Wei; Du, Jiang-Yuan; Jiang, Zedong; Okimura, Takasi; Oda, Tatsuya; Yu, Qing; Jin, Jun-O

    2014-01-01

    Marine-derived sulfated polysaccharides have been shown to possess certain anti-virus, anti-tumor, anti-inflammatory and anti-coagulant activities. However, the in vivo immunomodulatory effects of marine-derived pure compounds have been less well characterized. In this study, we investigated the effect of ascophyllan, a sulfated polysaccharide purified from Ascophyllum nodosum, on the maturation of mouse dendritic cells (DCs) in vitro and in vivo. Ascophyllan induced up-regulation of co-stimulatory molecules and production of pro-inflammatory cytokines in bone marrow-derived DCs (BMDCs). Moreover, in vivo administration of ascophyllan promotes up-regulation of CD40, CD80, CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen cDCs. Interestingly, ascophyllan induced a higher degree of co-stimulatory molecule up-regulation and pro-inflammatory cytokine production than fucoidan, a marine-derived polysaccharide with well-defined effect for promoting DC maturation. Ascophyllan also promoted the generation of IFN-γ-producing Th1 and Tc1 cells in the presence of DCs in an IL-12-dependent manner. Finally, myeloid differentiation primary response 88 (MyD88) signaling pathway was essential for DC maturation induced by ascophyllan. Taken together, these results demonstrate that ascophyllan induces DC maturation, and consequently enhances Th1 and Tc1 responses in vivo. This knowledge could facilitate the development of novel therapeutic strategies to combat infectious diseases and cancer. PMID:25026264

  1. Rapid generation of a mouse model for Middle East respiratory syndrome

    PubMed Central

    Zhao, Jincun; Li, Kun; Wohlford-Lenane, Christine; Agnihothram, Sudhakar S.; Fett, Craig; Zhao, Jingxian; Gale, Michael J.; Baric, Ralph S.; Enjuanes, Luis; Gallagher, Tom; McCray, Paul B.; Perlman, Stanley

    2014-01-01

    In this era of continued emergence of zoonotic virus infections, the rapid development of rodent models represents a critical barrier to public health preparedness, including the testing of antivirus therapy and vaccines. The Middle East respiratory syndrome coronavirus (MERS-CoV) was recently identified as the causative agent of a severe pneumonia. Given the ability of coronavirus to rapidly adapt to new hosts, a major public health concern is that MERS-CoV will further adapt to replication in humans, triggering a pandemic. No small-animal model for this infection is currently available, but studies suggest that virus entry factors can confer virus susceptibility. Here, we show that mice were sensitized to MERS-CoV infection by prior transduction with adenoviral vectors expressing the human host-cell receptor dipeptidyl peptidase 4. Mice developed a pneumonia characterized by extensive inflammatory-cell infiltration with virus clearance occurring 6–8 d after infection. Clinical disease and histopathological changes were more severe in the absence of type-I IFN signaling whereas the T-cell response was required for virus clearance. Using these mice, we demonstrated the efficacy of a therapeutic intervention (poly I:C) and a potential vaccine [Venezuelan equine encephalitis replicon particles expressing MERS-CoV spike protein]. We also found little protective cross-reactivity between MERS-CoV and the severe acute respiratory syndrome-CoV. Our results demonstrate that this system will be useful for MERS-CoV studies and for the rapid development of relevant animal models for emerging respiratory viral infections. PMID:24599590

  2. Evaluation of Camellia sinensis catechins as a swine antimicrobial feed additive that does not cause antibiotic resistance.

    PubMed

    Ohno, Akira; Kataoka, Shinichiro; Ishii, Yoshikazu; Terasaki, Toshiaki; Kiso, Masaaki; Okubo, Mitsuyuki; Yamaguchi, Keizo; Tateda, Kazuhiro

    2013-01-01

    Antimicrobial growth promoters (AGPs) have been banned and phased out because their use has been linked to the emergence and spread of antibiotic-resistant pathogens; however, the ban has had a marked impact on livestock production, and feed additive alternatives to AGPs are required. We focused on green tea leaves as potential alternatives to AGPs because they contain significant amounts of polyphenol catechins, which have antivirus and antimicrobial effects. We examined cross-resistance between epigallocatechin gallate (EGCG), which is the most abundant catechin of green tea leaves, and commercially available antimicrobials in clinically problematic antimicrobial-resistant bacteria, and whether bacteria have the ability to acquire resistance by consecutive passage in sub-inhibitory concentrations of EGCG. EGCG did not display any cross-resistance with reference antimicrobials and the bacteria did not acquire EGCG resistance. Further, we examined the growth-promoting effects of dried green tea leaves on the breeding of a new Japanese breed, Tokyo-X pigs. While the mortality rates of the green tea leaf (GTL) and AGP groups were both 11.1% (one in nine piglets), the mortality rate was 50% for the control group with an additive-free diet (four in eight piglets). The rate of body weight increase in both the GTL and AGP groups was approximately the same. The growth-promoting effects of green tea leaves and AGPs were similar, and there was no possibility that the antimicrobial properties of catechins caused the same problem as AGPs. Thus, it can be concluded that green tea leaves are a safe feed additive alternative to AGPs. PMID:23138151

  3. Physiological role of alternative oxidase (from yeasts to plants).

    PubMed

    Rogov, A G; Zvyagilskaya, R A

    2015-04-01

    Mitochondria of all so far studied organisms, with the exception of Archaea, mammals, some yeasts, and protists, contain, along with the classical phosphorylating cytochrome pathway, a so-called cyanide-insensitive alternative oxidase (AOX) localized on the matrix side of the mitochondrial inner membrane, and electron transport through which is not coupled with ATP synthesis and energy accumulation. Mechanisms underlying plentiful functions of AOX in organisms at various levels of organization ranging from yeasts to plants are considered. First and foremost, AOX provides a chance of cell survival after inhibiting the terminal components of the main respiratory chain or losing the ability to synthesize these components. The vitally important role of AOX is obvious in thermogenesis of thermogenic plant organs where it becomes the only terminal oxidase with a very high activity, and the energy of substrate oxidation by this respiratory pathway is converted into heat, thus promoting evaporation of volatile substances attracting pollinating insects. AOX plays a fundamentally significant role in alleviating or preventing oxidative stress, thus ensuring the defense against a wide range of stresses and adverse environmental conditions, such as changes in temperature and light intensities, osmotic stress, drought, and attack by incompatible strains of bacterial pathogens, phytopathogens, or their elicitors. Participation of AOX in pathogen survival during its existence inside the host, in antivirus defense, as well as in metabolic rearrangements in plants during embryogenesis and cell differentiation is described. Examples are given to demonstrate that AOX might be an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals. PMID:25869356

  4. Using gold nanorods core/silver shell nanostructures as model material to probe biodistribution and toxic effects of silver nanoparticles in mice.

    PubMed

    Meng, Jie; Ji, Yinglu; Liu, Jian; Cheng, Xuelian; Guo, Hua; Zhang, Weiqi; Wu, Xiaochun; Xu, Haiyan

    2014-09-01

    The aim of this work was to probe the biodistribution and toxic effects of silver nanoparticles (NPs) with powerful anti-bacterial and anti-virus activities. For this purpose, novel silver NPs with gold nanorod (NR) core and silver shell (Au@Ag NRs) were developed and employed as a model material. The inner gold core provided an excellent internal reference for tracking the NRs in vivo. After subcutaneous injection of Au@Ag NRs, silver and gold contents in the subcutis and organs were examined by inductively coupled plasma mass spectrometry at different time points within 28 days. Histological analysis, physiological function and complement faction 3 (C3) and 5a (C5a) measurement were performed over time to reveal the toxic effect of Au@Ag NRs in vivo. Experimental results showed that majority of the Au@Ag NRs remained in the injection site except for a small amount migrating into the lymph nodes. The silver shell was dissolved in the subcutaneous tissue and released silver ions rapidly, which resulted in detectable silver accumulation in most of the organs. The accumulated silver ions in the kidney not only interacted with the kidney cells membrane but also induced a rapid increase of complement fraction C3 followed by a significant consumption and C3a and C5a production significantly in the serum, which resulted in kidney oxidative damage and eventually led to the morphological changes and filtration function impairment of the glomerulus. The released silver ions also caused oxidative injury of subcutaneous tissue in the injection site. PMID:23837638

  5. Functional stability of 3D8 scFv, a nucleic acid-hydrolyzing single chain antibody, under different biochemical and physical conditions.

    PubMed

    Lee, Joungmin; Park, Hyunjoon; Kim, Minjae; Seo, Youngsil; Lee, Yeonjin; Byun, Sung June; Lee, Sukchan; Kwon, Myung-Hee

    2015-12-30

    3D8 single-chain Fv (scFv) is a catalytic nucleic acid antibody with anti-viral activity against a broad spectrum of viruses. Here we investigated the functional stability of 3D8 scFv to provide a basis for engineering a 3D8 scFv derivative and for developing stable formulations with improved stability and potential use as an anti-viral agent. The stability of 3D8 scFv was assessed by measuring its DNA-hydrolyzing activity under different biochemical and physical conditions using a fluorescence resonance energy transfer (FRET)-based method. In addition, the anti-influenza (H9N2) effect of 3D8 scFv was evaluated in A549 cells. 3D8 scFv was stable at 50°C for 6h at pH 7.2, for 3 days at pH 4-10 at 37°C and 30 days at pH 4-8 at 37°C. The stability was not affected by a reducing condition, freeze-thawing for up to 30 cycles, or lyophilization. Evaluation of the anti-virus effect showed that cells treated with 32-128 units of 3D8 scFv showed a 50% decrease in influenza replication compared to untreated cells. Based on its enzymatic stability in various biochemical and physical environments, 3D8 scFv holds good potential for development as an anti-viral therapeutic. PMID:26536531

  6. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells

    SciTech Connect

    Wakao, Kazufumi; Watanabe, Tadashi; Takadama, Tadatoshi; Ui, Sadaharu; Shigemi, Zenpei; Kagawa, Hiroki; Higashi, Chizuka; Ohga, Rie; Taira, Takahiro; Fujimuro, Masahiro

    2014-02-07

    Highlights: • Sangivamycin induces the apoptosis of B cell lymphoma PEL cells. • Sangivamycin suppresses Erk signaling by inhibiting Erk phosphorylation in PEL cells. • The activation of Erk signaling is essential for PEL cell survival. • Sangivamycin induces the apoptosis of PEL cells without production of progeny virus. • Sangivamycin may serve as a novel drug for the treatment of PEL. - Abstract: Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that sangivamycin may find clinical utility as a novel anti-cancer agent targeting PEL.

  7. Inhibitory effects of neochamaejasmin B on P-glycoprotein in MDCK-hMDR1 cells and molecular docking of NCB binding in P-glycoprotein.

    PubMed

    Pan, Lanying; Hu, Haihong; Wang, Xiangjun; Yu, Lushan; Jiang, Huidi; Chen, Jianzhong; Lou, Yan; Zeng, Su

    2015-01-01

    Stellera chamaejasme L. (Thymelaeaceae) is widely distributed in Mongolia, Tibet and the northern parts of China. Its roots are commonly used as "Langdu", which is embodied in the Pharmacopoeia of the P.R. China (2010) as a toxic Traditional Chinese Medicine. It is claimed to have antivirus, antitumor and antibacterial properties in China and other Asian countries. Studies were carried out to characterize the inhibition of neochamaejasmin B (NCB) on P-glycoprotein (P-gp, ABCB1, MDR1). Rhodamine-123 (R-123) transport and accumulation studies were performed in MDCK-hMDR1 cells. ABCB1 (MDR1) mRNA gene expression and P-gp protein expression were analyzed. Binding selectivity studies based on molecular docking were explored. R-123 transport and accumulation studies in MDCK-hMDR1 cells indicated that NCB inhibited the P-gp-mediated efflux in a concentration-dependent manner. RT-PCR and Western blot demonstrated that the P-gp expression was suppressed by NCB. To investigate the inhibition type of NCB on P-gp, Ki and Ki' values were determined by double-reciprocal plots in R-123 accumulation studies. Since Ki was greater than Ki', the inhibition of NCB on P-gp was likely a mixed type of competitive and non-competitive inhibition. The results were confirmed by molecular docking in our current work. The docking data indicated that NCB had higher affinity to P-gp than to Lig1 ((S)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one). PMID:25679052

  8. Procyanidins and butanol extract of Cinnamomi Cortex inhibit SARS-CoV infection.

    PubMed

    Zhuang, Min; Jiang, Hong; Suzuki, Yasuhiro; Li, Xiaoguang; Xiao, Peng; Tanaka, Takashi; Ling, Hong; Yang, Baofeng; Saitoh, Hiroki; Zhang, Lianfeng; Qin, Chuan; Sugamura, Kazuo; Hattori, Toshio

    2009-04-01

    We found that the butanol fraction of Cinnamomi Cortex (CC/Fr.2) showed moderate inhibitory activity in wild-type severe acute respiratory syndrome coronavirus (wtSARS-CoV) and HIV/SARS-CoV S pseudovirus infections. The inhibition on pseudovirus was also seen in cells pretreated with the CC and CC/Fr.2 (IC(50S), 283.4+/-16.3 and 149.5+/-13.5 microg/ml, respectively), however the highest activities on wtSARS-CoV were observed when the viruses were treated by the extracts before challenging (IC(50S), 43.1+/-2.8 and 7.8+/-0.3 microg/ml; SIs, 8.4 and 23.1, respectively). Among the compounds fractionated from CC, procyanidin A2 and procyanidin B1 showed moderate anti-wtSARS-CoV activity (IC(50S), 29.9+/-3.3 and 41.3+/-3.4 microM; SIs, 37.35 and 15.69, respectively). We also sought to determine whether they could interfere with the clathrin-dependent endocytosis pathway using transferrin receptor (TfR) as an indicator. CC/Fr.2 inhibited the internalization of TfR but the procyanidins did not. Taken together, CC/Fr.2 contains unknown substances, that could inhibit the infection, probably by interfering with endocytosis, and it also contains procyanidins that did not inhibit the internalization but inhibited the infection. Therefore, CC extracts contain anti-virus activities that act through distinct mechanisms according to differences in the compounds or mixtures. PMID:19428598

  9. Access Control of Web- and Java-Based Applications

    NASA Technical Reports Server (NTRS)

    Tso, Kam S.; Pajevski, Michael J.

    2013-01-01

    Cybersecurity has become a great concern as threats of service interruption, unauthorized access, stealing and altering of information, and spreading of viruses have become more prevalent and serious. Application layer access control of applications is a critical component in the overall security solution that also includes encryption, firewalls, virtual private networks, antivirus, and intrusion detection. An access control solution, based on an open-source access manager augmented with custom software components, was developed to provide protection to both Web-based and Javabased client and server applications. The DISA Security Service (DISA-SS) provides common access control capabilities for AMMOS software applications through a set of application programming interfaces (APIs) and network- accessible security services for authentication, single sign-on, authorization checking, and authorization policy management. The OpenAM access management technology designed for Web applications can be extended to meet the needs of Java thick clients and stand alone servers that are commonly used in the JPL AMMOS environment. The DISA-SS reusable components have greatly reduced the effort for each AMMOS subsystem to develop its own access control strategy. The novelty of this work is that it leverages an open-source access management product that was designed for Webbased applications to provide access control for Java thick clients and Java standalone servers. Thick clients and standalone servers are still commonly used in businesses and government, especially for applications that require rich graphical user interfaces and high-performance visualization that cannot be met by thin clients running on Web browsers

  10. Early lethality of shRNA-transgenic pigs due to saturation of microRNA pathways* #

    PubMed Central

    Dai, Zhen; Wu, Rong; Zhao, Yi-cheng; Wang, Kan-kan; Huang, Yong-ye; Yang, Xin; Xie, Zi-cong; Tu, Chang-chun; Ouyang, Hong-sheng; Wang, Tie-dong; Pang, Da-xin

    2014-01-01

    RNA interference (RNAi) is considered as a potential modality for clinical treatment and anti-virus animal breeding. Here, we investigate the feasibility of inhibiting classical swine fever virus (CSFV) replication by short hairpin RNA (shRNA) in vitro and in vivo. We generate four different shRNA-positive clonal cells and two types of shRNA-transgenic pigs. CSFV could be effectively inhibited in shRNA-positive clonal cells and tail tip fibroblasts of shRNA-transgenic pigs. Unexpectedly, an early lethality due to shRNA is observed in these shRNA-transgenic pigs. With further research on shRNA-positive clonal cells and transgenic pigs, we report a great induction of interferon (IFN)-responsive genes in shRNA-positive clonal cells, altered levels of endogenous microRNAs (miRNA), and their processing enzymes in shRNA-positive cells. What is more, abnormal expressions of miRNAs and their processing enzymes are also observed in the livers of shRNA-transgenic pigs, indicating saturation of miRNA/shRNA pathways induced by shRNA. In addition, we investigate the effects of shRNAs on the development of somatic cell nuclear transfer (SCNT) embryos. These results show that shRNA causes adverse effects in vitro and in vivo and shRNA-induced disruption of the endogenous miRNA pathway may lead to the early lethality of shRNA-transgenic pigs. We firstly report abnormalities of the miRNA pathway in shRNA-transgenic animals, which may explain the early lethality of shRNA-transgenic pigs and has important implications for shRNA-transgenic animal preparation. PMID:24793764

  11. A Novel MVA Vectored Chikungunya Virus Vaccine Elicits Protective Immunity in Mice

    PubMed Central

    Weger-Lucarelli, James; Chu, Haiyan; Aliota, Matthew T.; Partidos, Charalambos D.; Osorio, Jorge E.

    2014-01-01

    Background Chikungunya virus (CHIKV) is a re-emerging arbovirus associated with febrile illness often accompanied by rash and arthralgia that may persist for several years. Outbreaks are associated with high morbidity and create a public health challenge for countries affected. Recent outbreaks have occurred in both Europe and the Americas, suggesting CHIKV may continue to spread. Despite the sustained threat of the virus, there is no approved vaccine or antiviral therapy against CHIKV. Therefore, it is critical to develop a vaccine that is both well tolerated and highly protective. Methodology/Principal Findings In this study, we describe the construction and characterization of a modified Vaccinia virus Ankara (MVA) virus expressing CHIKV E3 and E2 proteins (MVA-CHIK) that protected several mouse models from challenge with CHIKV. In particular, BALB/c mice were completely protected against viremia upon challenge with CHIKV after two doses of MVA-CHIK. Additionally, A129 mice (deficient in IFNα/β) were protected from viremia, footpad swelling, and mortality. While high anti-virus antibodies were elicited, low or undetectable levels of neutralizing antibodies were produced in both mouse models. However, passive transfer of MVA-CHIK immune serum to naïve mice did not protect against mortality, suggesting that antibodies may not be the main effectors of protection afforded by MVA-CHIK. Furthermore, depletion of CD4+, but not CD8+ T-cells from vaccinated mice resulted in 100% mortality, implicating the indispensable role of CD4+ T-cells in the protection afforded by MVA-CHIK. Conclusions/Significance The results presented herein demonstrate the potential of MVA to effectively express CHIKV E3-E2 proteins and generate protective immune responses. Our findings challenge the assumption that only neutralizing antibodies are effective in providing protection against CHIKV, and provides a framework for the development of novel, more effective vaccine strategies to combat CHIKV. PMID:25058320

  12. Targeting N-glycan cryptic sugar moieties for broad-spectrum virus neutralization: progress in identifying conserved molecular targets in viruses of distinct phylogenetic origins.

    PubMed

    Wang, Denong; Tang, Jin; Tang, Jiulai; Wang, Lai-Xi

    2015-01-01

    Identifying molecular targets for eliciting broadly virus-neutralizing antibodies is one of the key steps toward development of vaccines against emerging viral pathogens. Owing to genomic and somatic diversities among viral species, identifying protein targets for broad-spectrum virus neutralization is highly challenging even for the same virus, such as HIV-1. However, viruses rely on host glycosylation machineries to synthesize and express glycans and, thereby, may display common carbohydrate moieties. Thus, exploring glycan-binding profiles of broad-spectrum virus-neutralizing agents may provide key information to uncover the carbohydrate-based virus-neutralizing epitopes. In this study, we characterized two broadly HIV-neutralizing agents, human monoclonal antibody 2G12 and Galanthus nivalis lectin (GNA), for their viral targeting activities. Although these agents were known to be specific for oligomannosyl antigens, they differ strikingly in virus-binding activities. The former is HIV-1 specific; the latter is broadly reactive and is able to neutralize viruses of distinct phylogenetic origins, such as HIV-1, severe acute respiratory syndrome coronavirus (SARS-CoV), and human cytomegalovirus (HCMV). In carbohydrate microarray analyses, we explored the molecular basis underlying the striking differences in the spectrum of anti-virus activities of the two probes. Unlike 2G12, which is strictly specific for the high-density Man9GlcNAc2Asn (Man9)-clusters, GNA recognizes a number of N-glycan cryptic sugar moieties. These include not only the known oligomannosyl antigens but also previously unrecognized tri-antennary or multi-valent GlcNAc-terminating N-glycan epitopes (Tri/m-Gn). These findings highlight the potential of N-glycan cryptic sugar moieties as conserved targets for broad-spectrum virus neutralization and suggest the GNA-model of glycan-binding warrants focused investigation. PMID:25774492

  13. PC viruses: How do they do that

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They've been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  14. PC viruses: How do they do that?

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They`ve been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  15. Diketopiperazine Derivatives from the Marine-Derived Actinomycete Streptomyces sp. FXJ7.328

    PubMed Central

    Wang, Pei; Xi, Lijun; Liu, Peipei; Wang, Yi; Wang, Wei; Huang, Ying; Zhu, Weiming

    2013-01-01

    Five new diketopiperazine derivatives, (3Z,6E)-1-N-methyl-3-benzylidene-6-(2S-methyl-3-hydroxypropylidene)piperazine-2,5-dione (1), (3Z,6E)-1-N-methyl-3-benzylidene-6-(2R-methyl-3-hydroxypropylidene)piperazine-2,5-dione (2), (3Z,6Z)-3-(4-hydroxybenzylidene)-6-isobutylidenepiperazine-2,5-dione (3), (3Z,6Z)-3-((1H-imidazol-5-yl)-methylene)-6-isobutylidenepiperazine-2,5-dione (4), and (3Z,6S)-3-benzylidene-6-(2S-but-2-yl)piperazine-2,5-dione (5), were isolated from the marine-derived actinomycete Streptomyces sp. FXJ7.328. The structures of 1–5 were determined by spectroscopic analysis, CD exciton chirality, the modified Mosher’s, Marfey’s and the C3 Marfey’s methods. Compound 3 showed modest antivirus activity against influenza A (H1N1) virus with an IC50 value of 41.5 ± 4.5 ?M. In addition, compound 6 and 7 displayed potent anti-H1N1 activity with IC50 value of 28.9 ± 2.2 and 6.8 ± 1.5 ?M, respectively. Due to the lack of corresponding data in the literature, the 13C NMR data of (3Z,6S)-3-benzylidene-6-isobutylpiperazine-2,5-dione (6) were also reported here for the first time. PMID:23538868

  16. Increase of cells expressing PD-L1 in bovine leukemia virus infection and enhancement of anti-viral immune responses in vitro via PD-L1 blockade

    PubMed Central

    2011-01-01

    The inhibitory receptor programmed death-1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1) are involved in immune evasion mechanisms for several pathogens causing chronic infections. Blockade of the PD-1/PD-L1 pathway restores anti-virus immune responses, with concomitant reduction in viral load. In a previous report, we showed that, in bovine leukemia virus (BLV) infection, the expression of bovine PD-1 is closely associated with disease progression. However, the functions of bovine PD-L1 are still unknown. To investigate the role of PD-L1 in BLV infection, we identified the bovine PD-L1 gene, and examined PD-L1 expression in BLV-infected cattle in comparison with uninfected cattle. The deduced amino acid sequence of bovine PD-L1 shows high homology to the human and mouse PD-L1. The proportion of PD-L1 positive cells, especially among B cells, was upregulated in cattle with the late stage of the disease compared to cattle at the aleukemic infection stage or uninfected cattle. The proportion of PD-L1 positive cells correlated positively with prediction markers for the progression of the disease such as leukocyte number, virus load and virus titer whilst on the contrary, it inversely correlated with the degree of interferon-gamma expression. Blockade of the PD-1/PD-L1 pathway in vitro by PD-L1-specific antibody upregulated the production of interleukin-2 and interferon-gamma, and correspondingly, downregulated the BLV provirus load and the proportion of BLV-gp51 expressing cells. These data suggest that PD-L1 induces immunoinhibition in disease progressed cattle during chronic BLV infection. Therefore, PD-L1 would be a potential target for developing immunotherapies against BLV infection. PMID:21943148

  17. Expansion of monocytic myeloid-derived suppressor cells dampens T cell function in HIV-1-seropositive individuals.

    PubMed

    Qin, Aiping; Cai, Weiping; Pan, Ting; Wu, Kang; Yang, Qiong; Wang, Nina; Liu, Yufeng; Yan, Dehong; Hu, Fengyu; Guo, Pengle; Chen, Xiaoping; Chen, Ling; Zhang, Hui; Tang, Xiaoping; Zhou, Jie

    2013-02-01

    T lymphocyte dysfunction contributes to human immunodeficiency virus type 1 (HIV-1) disease progression by impairing antivirus cellular immunity. However, the mechanisms of HIV-1 infection-mediated T cell dysfunction are not completely understood. Here, we provide evidence that expansion of monocytic myeloid-derived suppressor cells (M-MDSCs) suppressed T cell function in HIV-1-infected individuals. We observed a dramatic elevation of M-MDSCs (HLA-DR(-/low) CD11b(+) CD33(+/high) CD14(+) CD15(-) cells) in the peripheral blood of HIV-1-seropositive subjects (n = 61) compared with healthy controls (n = 51), despite efficacious antiretroviral therapy for nearly 2 years. The elevated M-MDSC frequency in HIV-1(+) subjects correlated with prognostic HIV-1 disease markers, including the HIV-1 load (r = 0.5957; P < 0.0001), CD4(+) T cell loss (r = -0.5312; P < 0.0001), and activated T cells (r = 0.4421; P = 0.0004). Functional studies showed that M-MDSCs from HIV-1(+) subjects suppressed T cell responses in both HIV-1-specific and antigen-nonspecific manners; this effect was dependent on the induction of arginase 1 and required direct cell-cell contact. Further investigations revealed that direct HIV-1 infection or culture with HIV-1-derived Tat protein significantly enhanced human MDSC generation in vitro, and MDSCs from healthy donors could be directly infected by HIV-1 to facilitate HIV-1 replication and transmission, indicating that a positive-feedback loop between HIV-1 infection and MDSC expansion existed. In summary, our studies revealed a novel mechanism of T cell dysfunction in HIV-1-infected individuals and suggested that targeting MDSCs may be a promising strategy for HIV-1 immunotherapy. PMID:23152536

  18. Luteolin inhibits viral-induced inflammatory response in RAW264.7 cells via suppression of STAT1/3 dependent NF-κB and activation of HO-1.

    PubMed

    Liu, Cheng-Wei; Lin, Hui-Wen; Yang, Deng-Jye; Chen, Shih-Yin; Tseng, Jung-Kai; Chang, Tien-Jye; Chang, Yuan-Yen

    2016-06-01

    Luteolin is a common dietary flavonoid present in Chinese herbal medicines that has been reported to have important anti-inflammatory properties. Previous studies have shown that luteolin is an anti-inflammatory and anti-oxidative agent. In this study, the anti-virus inflammatory capacity of luteolin and its molecular mechanisms of action were analyzed. The cytotoxic effects of luteolin were assessed in the presence or absence of pseudorabies virus (PRV) via LDH and MTT assays. The results showed that luteolin (<10μM) had no toxic effects and there were tendencies toward higher cell survival. In PRV-infected RAW264.7 cells, luteolin potently inhibited the production of NO, iNOS, COX-2 and inflammatory cytokine production. Luteolin did not inhibit the phosphorylation of ERK 1/2, p38, and JNK 1/2 either. We found that PRV-induced NF-κB activation is regulated through inhibition of STAT1and STAT3 phosphorylation in response to luteolin. Additionally, luteolin caused the induction of HO-1 via upregulation of Nrf2, both of which are involved in the secretion of proinflammatory mediators. The blockade of HO-1 expression with SnPP, a HO-1 inhibitor, attenuated HO-1 induction by luteolin and thus mitigated its anti-inflammatory effects during PRV-infected RAW264.7 cells. Taken together, our data indicate that luteolin diminishes the proinflammatory mediators NO, inflammatory cytokines and the expression of their regulatory genes, iNOS and COX-2, in PRV-infected RAW264.7 cells by inhibiting STAT1/3 dependent NF-κB activation and inducing Nrf2mediated HO-1 expression. PMID:27016074

  19. La prévention des infections par le virus respiratoire syncytial

    PubMed Central

    Robinson, JL

    2011-01-01

    RÉSUMÉ L’infection par le virus respiratoire syncytial (VRS) est la principale cause d’infections des voies respiratoires inférieures chez les jeunes enfants. Le palivizumab, un anticorps monoclonal anti-VRS, réduit le taux d’hospitalisation des enfants à haut risque mais est très coûteux. Le présent document de principes remplace les trois précédents documents de principes de la Société canadienne de pédiatrie sur le sujet et est mis à jour principalement pour traiter des récentes modifications aux lignes directrices de l’American Academy of Pediatrics dans le contexte canadien. Il contient une analyse des publications ainsi que des recommandations au sujet de l’utilisation du palivizumab chez les enfants à haut risque

  20. Progresos recientes en Astronomía de Rayos Gamma

    NASA Astrophysics Data System (ADS)

    Romero, G. E.

    Tras la exitosa misión del Compton Gamma-Ray Observatory durante los años 1990, la astronomía de rayos gamma ha entrado en una etapa de madurez, convirtiéndose en una de las principales herramientas para el estudio de procesos relativistas en el universo. En este reporte, presentaré una revisión de los principales tópicos abordados a través de estudios con rayos gamma en los últimos años, con particular énfasis en los intentos más recientes por establecer la naturaleza de las fuentes de rayos gamma no identificadas, detectadas por el instrumento EGRET.

  1. Urbanization and the groundwater budget, metropolitan Seoul area, Korea

    NASA Astrophysics Data System (ADS)

    Kim, Yoon-Young; Lee, Kang-Kun; Sung, Ig Hwan

    2001-07-01

    The city of Seoul is home to more than 10 million people in an area of 605 km2. Groundwater is ed for public water supply and industrial use, and to drain underground facilities and construction sites. Though most tap water is supplied from the Han River, the quantity and quality of groundwater is of great concern to Seoul's citizens, because the use of groundwater for drinking water is continuously increasing. This study identifies the major factors affecting the urban water budget and quality of groundwater in the Seoul area and estimates the urban water budget. These factors include leakage from the municipal water-supply system and sewer systems, precipitation infiltration, water-level fluctuations of the Han River, the subway pumping system, and domestic pumping. The balance between groundwater recharge and discharge is near equilibrium. However, the quality of groundwater and ability to control contaminant fluxes are impeded by sewage infiltration, abandoned landfills, waste dumps, and abandoned wells. Résumé. La ville de Séoul possède une population de plus de 10 millions d'habitants, pour une superficie de 605 km2. Les eaux souterraines sont pompées pour l'eau potable et pour les usages industriels, ainsi que pour drainer les équipements souterrains et les sites en construction. Bien que l'essentiel de l'eau potable provienne de la rivière Han, la quantité et la qualité de l'eau souterraine présentent un grand intérêt pour les habitants de Séoul, parce qu'on utilise de plus en plus l'eau souterraine pour l'eau potable. Cette étude identifie les facteurs principaux qui affectent la qualité de l'eau souterraine dans la région de Séoul et fait l'estimation du bilan d'eau urbaine. Les principaux facteurs affectant le bilan d'eau urbaine et la qualité de l'eau souterraine sont les fuites du réseau d'adduction et du réseau d'égouts, l'infiltration des eaux de précipitation, les fluctuations du niveau de la rivière Han, le réseau de pompage du métro et les pompages privés. Le bilan entre la recharge de la nappe et sa décharge est proche de l'équilibre. Cependant, les infiltrations d'eaux usées, les décharges abandonnées, les décharges d'ordures et les puits abandonnés portent atteinte à la qualité de l'eau souterraine et à la capacité de contrôler les flux de contaminants. Resumen. La ciudad de Seúl tiene más de 10 millones de habitantes en un área de 605 km2. Se bombea aguas subterráneas para abastecimiento urbano y para usos industriales, así como para el drenaje de instalaciones subterráneas y de solares en construcción. Aunque la mayor parte del agua de boca procede del río Han, los ciudadanos de Seúl están muy concienciados por la cantidad y calidad de las aguas subterráneas, ya que su explotación para uso de boca está experimentando un continuo incremento. El presente estudio identifica los factores que más afectan a la calidad de las aguas subterráneas en el área de Seúl y hace una estimación del balance de agua en el territorio urbano. Entre los factores principales que afectan al balance y a la calidad de las aguas subterráneas, se incluye el lixiviado de la red municipal de suministro y de la red de alcantarillado, la infiltración de agua de lluvia, las fluctuaciones del nivel del río Han, el sistema de bombeo del metro y los bombeos domésticos. El balance entre la recarga y la descarga en el acuífero está próximo al equilibrio. Sin embargo, la calidad de las aguas subterráneas y la capacidad de controlar los flujos de contaminación están amenazadas por la infiltración de aguas residuales, vertederos abandonados, depósitos de residuos y pozos abanadonados.

  2. A geochemical and geophysical approach to derive a conceptual circulation model of CO2-rich mineral waters: A case study of Vilarelho da Raia, northern Portugal

    NASA Astrophysics Data System (ADS)

    Marques, J. M.; Santos, Monteiro; Graça, R. C.; Castro, R.; Aires-Barros, L.; Mendes Victor, L. A.

    2001-11-01

    The Vilarelho da Raia-Chaves region, located in northern Portugal adjacent to the Spanish border, is characterized by both hot and cold CO2-rich mineral waters issuing from springs and drilled wells. The present paper updates the conceptual circulation model of the Vilarelho da Raia cold CO2-rich mineral waters. Vilarelho da Raia mineral waters, dominated by Na and HCO3 ions, have formed mainly by interaction with CO2 of deep-seated mantle origin. The δ18O, δ2H and 3H values indicate that these waters are the result of meteoric waters infiltrating into Larouco Mountain, NW of Vilarelho da Raia, circulating at shallow depths in granitic rocks and moving into Vilarelho da Raia area. The conceptual geochemical and geophysical circulation model indicates that the hot and cold CO2-rich mineral waters of Chaves (76 °C) and Vilarelho da Raia (17 °C) should be considered manifestations of similar but not the same geohydrological systems. Résumé. La région de Vilarelho da Raia - Chaves, située au Portugal près de la frontière Espagnole, est caractérisée par des eaux carbogazeuses, chaudes et froides, émergeant à des sources et dans des puits. Ce travail constitue une mise au point du modèle conceptuel de circulation des eaux minérales carbogazeuses froides de Vilarelho da Raia. Les eaux minérales de Vilarelho da Raia, dans lesquelles les ions Na and HCO3 sont dominants, résultent principalement d'interactions avec du CO2 d'origine mantellique. Les δ18O, les δ2H, et les teneurs en 3H indiquent que ces eaux proviennent de l'infiltration d'eaux météoriques dans le Mont Larouco au NW de Vilarelho da Raia, circulant à faible profondeur dans les granites en direction de la région de Vilarelho da Raia. Le modèle de circulation géochimique et géophysique conduit à penser que les eaux minérales carbogazeuses chaudes et froides de Chaves (76 °C) et de Vilarelho da Raia (17 °C) doivent être considérées comme des manifestations de systèmes hydrogéologiques similaires, mais non identiques. Resumen. La región de Vilarelho-Chaves está situada en el Norte de Portugal, junto a la frontera con España. Se caracteriza por la existencia de aguas minerales calientes y frías enriquecidas en CO2, que descargan mediante manantiales y pozos. El artículo tiene como objetivo la actualización del modelo conceptual de flujo de las aguas frías de Vilarelho de Raia, que son ricas en CO2. Dichas aguas se han formado fundamentalmente por la interacción con el CO2 procedente del manto profundo, y son del tipo bicarbonatado sódico. Los valores de δ18O, δ2H y 3H indican que proceden de la infiltración de agua meteórica en la Montaña Larouco -al Noroeste de Vilarelho de Raia-, que circulan a poca profundidad en un medio formado por de rocas graníticas y se mueven hacia el área de Vilarelho de Raia. El modelo conceptual de flujo, basado en datos geoquímicos y geofísicos, indica que las aguas minerales calientes de Chaves (76 °C) y las frías de Vilarelho de Raia (17 °C), ambas enriquecidas en CO2, no deben ser consideradas como manifestaciones de un único sistema hidrogeológico, sino de dos similares.

  3. Rupture sous-cutanée du tendon long extenseur du pouce: à propos de 5 cas

    PubMed Central

    Abdelillah, Rachid; Abbassi, Najib; Erraji, Moncef; Abdeljawad, Najib; Yacoubi, Hicham; Daoudi, Abdelkrim

    2014-01-01

    La rupture spontanée du muscle long extenseur du pouce (EPL) du tendon au niveau du poignet est rare et principalement rapportés après fracture du radius distal à tubercule de Lister, dans la synovite, ténosynovite ou la polyarthrite rhumatoïde. Nous rapportons 5 cas de rupture spontanée du tendon long extenseur du pouce, traités par une greffe ou un transfert tendineux. PMID:25317233

  4. Des lasers à excimères pour cristalliser le silicium des écrans plats : pourquoi ? comment ?

    NASA Astrophysics Data System (ADS)

    Prat, C.

    2003-06-01

    Les contraintes techniques et économiques de la fabrication d'écrans plats à cristaux liquides à matrice active ont suscité de nombreuses études de procédés de cristallisation de couches minces de silicium par laser à excimères, exploitant principalement trois types de phénomènes physiques, dans le but d'obtenir des cristaux micrométriques les plus uniformes possible.

  5. El Informe a la Nación sobre el Estado del Cáncer, 1975-2012

    Cancer.gov

    El Informe a la Nación sobre el Estado del Cáncer (1975-2012) indica que continuó la baja de tasas de mortalidad de todos los cánceres juntos, así como de la mayoría de los cánceres en hombres y mujeres de todos los grupos raciales y étnicos principales.

  6. El medio interestelar alrededor de estrellas Of: HD 108

    NASA Astrophysics Data System (ADS)

    Cappa, C.; Testori, J. C.

    Hemos analizado la distribución del hidrógeno neutro interestelar en la vecindad de la estrella Of HD 108 en base a perfiles de la línea de 21 cm. Estos datos nos han permitido encontrar una probable burbuja interestelar asociada a la estrella. Comparamos estos resultados con la emisión en otros rangos espectrales y estimamos los principales parámetros físicos de la estructura.

  7. Connecting to the Internet Securely; Protecting Home Networks CIAC-2324

    SciTech Connect

    Orvis, W J; Krystosek, P; Smith, J

    2002-11-27

    With more and more people working at home and connecting to company networks via the Internet, the risk to company networks to intrusion and theft of sensitive information is growing. Working from home has many positive advantages for both the home worker and the company they work for. However, as companies encourage people to work from home, they need to start considering the interaction of the employee's home network and the company network he connects to. This paper discusses problems and solutions related to protection of home computers from attacks on those computers via the network connection. It does not consider protection of those systems from people who have physical access to the computers nor does it consider company laptops taken on-the-road. Home networks are often targeted by intruders because they are plentiful and they are usually not well secured. While companies have departments of professionals to maintain and secure their networks, home networks are maintained by the employee who may be less knowledgeable about network security matters. The biggest problems with home networks are that: Home networks are not designed to be secure and may use technologies (wireless) that are not secure; The operating systems are not secured when they are installed; The operating systems and applications are not maintained (for security considerations) after they are installed; and The networks are often used for other activities that put them at risk for being compromised. Home networks that are going to be connected to company networks need to be cooperatively secured by the employee and the company so they do not open up the company network to intruders. Securing home networks involves many of the same operations as securing a company network: Patch and maintain systems; Securely configure systems; Eliminate unneeded services; Protect remote logins; Use good passwords; Use current antivirus software; and Moderate your Internet usage habits. Most of these items do not take a lot of work, but require an awareness of the risks involved in not doing them or doing them incorrectly. The security of home networks and communications with company networks can be significantly improved by adding an appropriate software or hardware firewall to the home network and using a protected protocol such as Secure Sockets Layer (SSL), a Virtual Private Network (VPN), or Secure Shell (SSH) for connecting to the company network.

  8. Pseudo-chaotic oscillations in CRISPR-virus coevolution predicted by bifurcation analysis

    PubMed Central

    2014-01-01

    Background The CRISPR-Cas systems of adaptive antivirus immunity are present in most archaea and many bacteria, and provide resistance to specific viruses or plasmids by inserting fragments of foreign DNA into the host genome and then utilizing transcripts of these spacers to inactivate the cognate foreign genome. The recent development of powerful genome engineering tools on the basis of CRISPR-Cas has sharply increased the interest in the diversity and evolution of these systems. Comparative genomic data indicate that during evolution of prokaryotes CRISPR-Cas loci are lost and acquired via horizontal gene transfer at high rates. Mathematical modeling and initial experimental studies of CRISPR-carrying microbes and viruses reveal complex coevolutionary dynamics. Results We performed a bifurcation analysis of models of coevolution of viruses and microbial host that possess CRISPR-Cas hereditary adaptive immunity systems. The analyzed Malthusian and logistic models display complex, and in particular, quasi-chaotic oscillation regimes that have not been previously observed experimentally or in agent-based models of the CRISPR-mediated immunity. The key factors for the appearance of the quasi-chaotic oscillations are the non-linear dependence of the host immunity on the virus load and the partitioning of the hosts into the immune and susceptible populations, so that the system consists of three components. Conclusions Bifurcation analysis of CRISPR-host coevolution model predicts complex regimes including quasi-chaotic oscillations. The quasi-chaotic regimes of virus-host coevolution are likely to be biologically relevant given the evolutionary instability of the CRISPR-Cas loci revealed by comparative genomics. The results of this analysis might have implications beyond the CRISPR-Cas systems, i.e. could describe the behavior of any adaptive immunity system with a heritable component, be it genetic or epigenetic. These predictions are experimentally testable. Reviewers’ reports This manuscript was reviewed by Sandor Pongor, Sergei Maslov and Marek Kimmel. For the complete reports, go to the Reviewers’ Reports section. PMID:24986220

  9. Activation of Type I and III Interferon Signalling Pathways Occurs in Lung Epithelial Cells Infected with Low Pathogenic Avian Influenza Viruses

    PubMed Central

    Sutejo, Richard; Yeo, Dawn S.; Myaing, Myint Zu; Hui, Chen; Xia, Jiajia; Ko, Debbie; Cheung, Peter C. F.; Tan, Boon-Huan; Sugrue, Richard J.

    2012-01-01

    The host response to the low pathogenic avian influenza (LPAI) H5N2, H5N3 and H9N2 viruses were examined in A549, MDCK, and CEF cells using a systems-based approach. The H5N2 and H5N3 viruses replicated efficiently in A549 and MDCK cells, while the H9N2 virus replicated least efficiently in these cell types. However, all LPAI viruses exhibited similar and higher replication efficiencies in CEF cells. A comparison of the host responses of these viruses and the H1N1/WSN virus and low passage pH1N1 clinical isolates was performed in A549 cells. The H9N2 and H5N2 virus subtypes exhibited a robust induction of Type I and Type III interferon (IFN) expression, sustained STAT1 activation from between 3 and 6 hpi, which correlated with large increases in IFN-stimulated gene (ISG) expression by 10 hpi. In contrast, cells infected with the pH1N1 or H1N1/WSN virus showed only small increases in Type III IFN signalling, low levels of ISG expression, and down-regulated expression of the IFN type I receptor. JNK activation and increased expression of the pro-apoptotic XAF1 protein was observed in A549 cells infected with all viruses except the H1N1/WSN virus, while MAPK p38 activation was only observed in cells infected with the pH1N1 and the H5 virus subtypes. No IFN expression and low ISG expression levels were generally observed in CEF cells infected with either AIV, while increased IFN and ISG expression was observed in response to the H1N1/WSN infection. These data suggest differences in the replication characteristics and antivirus signalling responses both among the different LPAI viruses, and between these viruses and the H1N1 viruses examined. These virus-specific differences in host cell signalling highlight the importance of examining the host response to avian influenza viruses that have not been extensively adapted to mammalian tissue culture. PMID:22470468

  10. Clusters of orthologous genes for 41 archaeal genomes and implications for evolutionary genomics of archaea

    PubMed Central

    Makarova, Kira S; Sorokin, Alexander V; Novichkov, Pavel S; Wolf, Yuri I; Koonin, Eugene V

    2007-01-01

    Background An evolutionary classification of genes from sequenced genomes that distinguishes between orthologs and paralogs is indispensable for genome annotation and evolutionary reconstruction. Shortly after multiple genome sequences of bacteria, archaea, and unicellular eukaryotes became available, an attempt on such a classification was implemented in Clusters of Orthologous Groups of proteins (COGs). Rapid accumulation of genome sequences creates opportunities for refining COGs but also represents a challenge because of error amplification. One of the practical strategies involves construction of refined COGs for phylogenetically compact subsets of genomes. Results New Archaeal Clusters of Orthologous Genes (arCOGs) were constructed for 41 archaeal genomes (13 Crenarchaeota, 27 Euryarchaeota and one Nanoarchaeon) using an improved procedure that employs a similarity tree between smaller, group-specific clusters, semi-automatically partitions orthology domains in multidomain proteins, and uses profile searches for identification of remote orthologs. The annotation of arCOGs is a consensus between three assignments based on the COGs, the CDD database, and the annotations of homologs in the NR database. The 7538 arCOGs, on average, cover ~88% of the genes in a genome compared to a ~76% coverage in COGs. The finer granularity of ortholog identification in the arCOGs is apparent from the fact that 4538 arCOGs correspond to 2362 COGs; ~40% of the arCOGs are new. The archaeal gene core (protein-coding genes found in all 41 genome) consists of 166 arCOGs. The arCOGs were used to reconstruct gene loss and gene gain events during archaeal evolution and gene sets of ancestral forms. The Last Archaeal Common Ancestor (LACA) is conservatively estimated to possess 996 genes compared to 1245 and 1335 genes for the last common ancestors of Crenarchaeota and Euryarchaeota, respectively. It is inferred that LACA was a chemoautotrophic hyperthermophile that, in addition to the core archaeal functions, encoded more idiosyncratic systems, e.g., the CASS systems of antivirus defense and some toxin-antitoxin systems. Conclusion The arCOGs provide a convenient, flexible framework for functional annotation of archaeal genomes, comparative genomics and evolutionary reconstructions. Genomic reconstructions suggest that the last common ancestor of archaea might have been (nearly) as advanced as the modern archaeal hyperthermophiles. ArCOGs and related information are available at: . Reviewers This article was reviewed by Peer Bork, Patrick Forterre, and Purificacion Lopez-Garcia. PMID:18042280

  11. Binding and transepithelial transport of immunoglobulins by intestinal M cells: demonstration using monoclonal IgA antibodies against enteric viral proteins.

    PubMed

    Weltzin, R; Lucia-Jandris, P; Michetti, P; Fields, B N; Kraehenbuhl, J P; Neutra, M R

    1989-05-01

    M cells of intestinal epithelia overlying lymphoid follicles endocytose luminal macromolecules and microorganisms and deliver them to underlying lymphoid tissue. The effect of luminal secretory IgA antibodies on adherence and transepithelial transport of antigens and microorganisms by M cells is unknown. We have studied the interaction of monoclonal IgA antibodies directed against specific enteric viruses, or the hapten trinitrophenyl (TNP), with M cells. To produce monospecific IgA antibodies against mouse mammary tumor virus (MMTV) and reovirus type 1, Peyer's patch cells from mucosally immunized mice were fused with myeloma cells, generating hybridomas that secreted virus-specific IgA antibodies in monomeric and polymeric forms. One of two anti-MMTV IgA antibodies specifically bound the viral surface glycoprotein gp52, and 3 of 10 antireovirus IgA antibodies immunoprecipitated sigma 3 and mu lc surface proteins. 35S-labeled IgA antibodies injected intravenously into rats were recovered in bile as higher molecular weight species, suggesting that secretory component had been added on passage through the liver. Radiolabeled or colloidal gold-conjugated mouse IgA was injected into mouse, rat, and rabbit intestinal loops containing Peyer's patches. Light microscopic autoradiography and EM showed that all IgA antibodies (antivirus or anti-TNP) bound to M cell luminal membranes and were transported in vesicles across M cells. IgA-gold binding was inhibited by excess unlabeled IgA, indicating that binding was specific. IgG-gold also adhered to M cells and excess unlabeled IgG inhibited IgA-gold binding; thus binding was not isotype-specific. Immune complexes consisting of monoclonal anti-TNP IgA and TNP-ferritin adhered selectively to M cell membranes, while TNP-ferritin alone did not. These results suggest that selective adherence of luminal antibody to M cells may facilitate delivery of virus-antibody complexes to mucosal lymphoid tissue, enhancing subsequent secretory immune responses or facilitating viral invasion. PMID:2541137

  12. Extensive structural change of the envelope protein of dengue virus induced by a tuned ionic strength: conformational and energetic analyses.

    PubMed

    Degrève, Léo; Fuzo, Carlos A; Caliri, Antonio

    2012-12-01

    The Dengue has become a global public health threat, with over 100 million infections annually; to date there is no specific vaccine or any antiviral drug. The structures of the envelope (E) proteins of the four known serotype of the dengue virus (DENV) are already known, but there are insufficient molecular details of their structural behavior in solution in the distinct environmental conditions in which the DENVs are submitted, from the digestive tract of the mosquito up to its replication inside the host cell. Such detailed knowledge becomes important because of the multifunctional character of the E protein: it mediates the early events in cell entry, via receptor endocytosis and, as a class II protein, participates determinately in the process of membrane fusion. The proposed infection mechanism asserts that once in the endosome, at low pH, the E homodimers dissociate and insert into the endosomal lipid membrane, after an extensive conformational change, mainly on the relative arrangement of its three domains. In this work we employ all-atom explicit solvent Molecular Dynamics simulations to specify the thermodynamic conditions in that the E proteins are induced to experience extensive structural changes, such as during the process of reducing pH. We study the structural behavior of the E protein monomer at acid pH solution of distinct ionic strength. Extensive simulations are carried out with all the histidine residues in its full protonated form at four distinct ionic strengths. The results are analyzed in detail from structural and energetic perspectives, and the virtual protein movements are described by means of the principal component analyses. As the main result, we found that at acid pH and physiological ionic strength, the E protein suffers a major structural change; for lower or higher ionic strengths, the crystal structure is essentially maintained along of all extensive simulations. On the other hand, at basic pH, when all histidine residues are in the unprotonated form, the protein structure is very stable for ionic strengths ranging from 0 to 225 mM. Therefore, our findings support the hypothesis that the histidines constitute the hot points that induce configurational changes of E protein in acid pH, and give extra motivation to the development of new ideas for antivirus compound design. PMID:23160852

  13. Preclinical pharmacology and toxicology study of Ad-hTERT-E1a-Apoptin, a novel dual cancer-specific oncolytic adenovirus

    SciTech Connect

    Qi, Yanxin; Guo, Huanhuan; Hu, Ningning; He, Dongyun; Zhang, Shi; Chu, Yunjie; Huang, Yubin; Li, Xiao; Sun, LiLi; Jin, Ningyi

    2014-10-15

    Clinical studies have demonstrated that conditionally replicating adenovirus is safe. We constructed an oncolytic adenovirus, Ad-hTERT-E1a-Apoptin, using a cancer-specific promoter (human telomerase reverse transcriptase promoter, hTERTp) and a cancer cell-selective apoptosis-inducing gene (Apoptin). Ad-hTERT-E1a-Apoptin was proven effective both in vitro and in vivo in our previous study. In this study, the preclinical safety profiles of Ad-hTERT-E1a-Apoptin in animal models were investigated. At doses of 5.0 × 10{sup 8}, 2.5 × 10{sup 9}, and 1.25 × 10{sup 10} viral particles (VP)/kg, Ad-hTERT-E1a-Apoptin had no adverse effects on mouse behavior, muscle cooperation, sedative effect, digestive system, and nervous systems, or on beagle cardiovascular and respiratory systems at 5.0 × 10{sup 8}, 2.5 × 10{sup 9}, and 1.25 × 10{sup 10} VP/kg doses. In acute toxicity tests in mice, the maximum tolerated dose > 5 × 10{sup 10} VP/kg. There was no inflammation or ulceration at the injection sites within two weeks. In repeat-dose toxicological studies, the no observable adverse effect levels of Ad-hTERT-E1a-Apoptin in rats (1.25 × 10{sup 10} VP/kg) and beagles (2.5 × 10{sup 9} VP/kg) were 62.5- and 12.5-fold of the proposed clinical dose, respectively. The anti-virus antibody was produced in animal sera. Bone marrow examination revealed no histopathological changes. Guinea pigs sensitized by three repeated intraperitoneal injections of 1.35 × 10{sup 10} VP/mL Ad-hTERT-E1a-Apoptin each and challenged by one intravenous injection of 1.67 × 10{sup 8} VP/kg Ad-hTERT-E1a-Apoptin did not exhibit any sign of systemic anaphylaxis. Our data from different animal models suggest that Ad-hTERT-E1a-Apoptin is a safe anti-tumor therapeutic agent. - Highlights: • We use the rodents and non-rodents animal models to evaluation Ad-hTERT-E1a-Apoptin. • Ad-hTERT-E1a-Apoptin is a safe anti-tumor therapeutic agent. • Demonstrate the safety and feasibility dose of injected Ad-hTERT-E1a-Apoptin.

  14. Network Penetration Testing and Research

    NASA Technical Reports Server (NTRS)

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised network, computers and devices can be penetrated through deployed exploits. This paper will illustrate the research done to test ability to penetrate a network without user interaction, in order to retrieve personal information from a targeted host.

  15. Preclinical pharmacology and toxicology study of Ad-hTERT-E1a-Apoptin, a novel dual cancer-specific oncolytic adenovirus.

    PubMed

    Qi, Yanxin; Guo, Huanhuan; Hu, Ningning; He, Dongyun; Zhang, Shi; Chu, Yunjie; Huang, Yubin; Li, Xiao; Sun, LiLi; Jin, Ningyi

    2014-10-15

    Clinical studies have demonstrated that conditionally replicating adenovirus is safe. We constructed an oncolytic adenovirus, Ad-hTERT-E1a-Apoptin, using a cancer-specific promoter (human telomerase reverse transcriptase promoter, hTERTp) and a cancer cell-selective apoptosis-inducing gene (Apoptin). Ad-hTERT-E1a-Apoptin was proven effective both in vitro and in vivo in our previous study. In this study, the preclinical safety profiles of Ad-hTERT-E1a-Apoptin in animal models were investigated. At doses of 5.0×10(8), 2.5×10(9), and 1.25×10(10) viral particles (VP)/kg, Ad-hTERT-E1a-Apoptin had no adverse effects on mouse behavior, muscle cooperation, sedative effect, digestive system, and nervous systems, or on beagle cardiovascular and respiratory systems at 5.0×10(8), 2.5×10(9), and 1.25×10(10) VP/kg doses. In acute toxicity tests in mice, the maximum tolerated dose>5×10(10) VP/kg. There was no inflammation or ulceration at the injection sites within two weeks. In repeat-dose toxicological studies, the no observable adverse effect levels of Ad-hTERT-E1a-Apoptin in rats (1.25×10(10) VP/kg) and beagles (2.5×10(9) VP/kg) were 62.5- and 12.5-fold of the proposed clinical dose, respectively. The anti-virus antibody was produced in animal sera. Bone marrow examination revealed no histopathological changes. Guinea pigs sensitized by three repeated intraperitoneal injections of 1.35×10(10) VP/mL Ad-hTERT-E1a-Apoptin each and challenged by one intravenous injection of 1.67×10(8) VP/kg Ad-hTERT-E1a-Apoptin did not exhibit any sign of systemic anaphylaxis. Our data from different animal models suggest that Ad-hTERT-E1a-Apoptin is a safe anti-tumor therapeutic agent. PMID:25151223

  16. Establishment of Myotis myotis Cell Lines - Model for Investigation of Host-Pathogen Interaction in a Natural Host for Emerging Viruses

    PubMed Central

    He, Xiaocui; Korytář, Tomáš; Zhu, Yaqing; Pikula, Jiří; Bandouchova, Hana; Zukal, Jan; Köllner, Bernd

    2014-01-01

    Bats are found to be the natural reservoirs for many emerging viruses. In most cases, severe clinical signs caused by such virus infections are normally not seen in bats. This indicates differences in the virus-host interactions and underlines the necessity to develop natural host related models to study these phenomena. Due to the strict protection of European bat species, immortalized cell lines are the only alternative to investigate the innate anti-virus immune mechanisms. Here, we report about the establishment and functional characterization of Myotis myotis derived cell lines from different tissues: brain (MmBr), tonsil (MmTo), peritoneal cavity (MmPca), nasal epithelium (MmNep) and nervus olfactorius (MmNol) after immortalization by SV 40 large T antigen. The usefulness of these cell lines to study antiviral responses has been confirmed by analysis of their susceptibility to lyssavirus infection and the mRNA patterns of immune-relevant genes after poly I:C stimulation. Performed experiments indicated varying susceptibility to lyssavirus infection with MmBr being considerably less susceptible than the other cell lines. Further investigation demonstrated a strong activation of interferon mediated antiviral response in MmBr contributing to its resistance. The pattern recognition receptors: RIG-I and MDA5 were highly up-regulated during rabies virus infection in MmBr, suggesting their involvement in promotion of antiviral responses. The presence of CD14 and CD68 in MmBr suggested MmBr cells are microglia-like cells which play a key role in host defense against infections in the central nervous system (CNS). Thus the expression pattern of MmBr combined with the observed limitation of lyssavirus replication underpin a protective mechanism of the CNS controlling the lyssavirus infection. Overall, the established cell lines are important tools to analyze antiviral innate immunity in M. myotis against neurotropic virus infections and present a valuable tool for a broad spectrum of future investigations in cellular biology of M. myotis. PMID:25295526

  17. Measurement and evaluation of national family planning programs.

    PubMed

    Mauldin, W P

    1967-03-01

    RESUMEN: En los últimos quince años diez paises han inaugurado programas nacionales de planeamiento familiar: India, Pakistán, Corea del Sur, Taiwan, Turquía, Malasia, Ceilán, Túez, la República Arabe Unida, y Marruecos. Otros paises, incluyendo Tailandia, Hong Kong, Singapur, Kenya, Barbados, Trinidad y los Estados Unidos, apoyan y/o estimulan actividades de planeamiento familiar. En la mayor parte de los casos la razón fundamental del programa ha sido que si la tasa de crecimiento poblacional disminuyera, aumentaría la tasa de crecimiento económico.Las metas de largo alcance, expresadas típicamente en términos de reducir las tasa.de de natalidad o de crecimiento, tienen su ejemplo en el propósito de Pakistán de reducir su tasa de crecimiento a 26 para 1970; el de Corea de reducir su tasa de natalidad a 20 para 1971; y el de India de reducir su tasa de natalidad a 25 para 1973.Los objectivos intermedios, que cubren diversos aspectos del pro grama, incluyen metas específicas para un determinado mes a año, considerando personal, la adquisición de anticonceptivos, y el número de usarios por método. Las metas específicas anuales de aceptantes de dispositivos intrauterinos (IUD), para Taiwán, Corea, Túnez, Pakistán e India, son comunes, tanto por la naturaleza del artefacto, como por la facilidad de medición de los que continúan utilizándolos. El programa de evaluación en Taiwán, que trata de medir por diversos medios los efectos inmediatos, mediatos y de largo plazo del programa de planeamiento familiar sirve de modelo. El propósito de la evaiuación de un programa de planeamiento familiar es contribuir a la efectividad y eficiencia del programa, midiendo y analizando su progreso. Las áreas a medir pueden ser clasificadas como- (1) conocimiento acerca de; (2) actitudes hacia; (3) práctica de control de natalidad; y (4) nivel de fecundidad.Un buen sistema de evaluación debería incluir: A. Un buen conjunto de estadísticas de servicio presentadas en formularios estandarizados, en las siguienies formas: 1. Informes nensuales por áreas administrativas, sobre los actuales servicios de planeamiento familiar proporcionados en la actualidad, de carácter permanente o de larga duración (al presente, esterilización y IUD de acuerdo a las siguientes características del receptor: residencia, edad, paridad (número de hijos vivos por sexo), y donde se enteró del programa, si es posible "clase";(probablemente educación de la madre, pero posiblemente ocupación del esposo, ingreso, o equivalente); prácticas anticonceptivas anteriores; intervalo; y deseo de tener más hijos. En un programa grande estos datos pueden obtenerse en base a una muestra. 2. Informes mensuales sobre la distribución de suministros anticonceptivos (condones, píldoras, sustancias efervescentes, etc.), los primeros suministros deben ir acompañados de un registro de las características del recipiente, como anteriormente; los suministros subsecuentes se regietrarán sólo en volumen bruto. Esto también se aplicará al ritmo, donde éste método se enseñe a un número considerable de mujeres. 3. Informes regulares sobre las actividades de planeamiento familiar de médicos privados, como una estimación del efecto catalítico del programa del gobierno sobre ci sector privado. 4. Datos generates mensuales, ppr áreas admirtistrativas importantes, sabre: visitas domiciliarias, reuniones, cuñas radiates y televisadas, avisos en los periódicos y personal que trabaja. 5. Para propósitos de seguimiento una entrevi eta de campo cada 6 a 12 meses a cada N mujer de las listas para (1) y (2) arriba, en un total de 300 o 400, para conocer las tasas de continuación y las razones de abandono (ej: desea otro hijo, insatisfecha can ci método, otras). Las mue.stras podrían ser de 300 cada una, con una supuesta experiencia de 6, 12, 18 y 24 meses. B. Un buen conjunto de datos sobre costa (datos sobre cotos actulaes atribuíbles directamente al programa de planeamiento familiar) fraccionados par áreas principales y cinco a seis categorías de costos importantes tales coma: adminietración, personal de campo, publicidad, suministros, etc. C. Un buen conjunto de dates globales sobre la distribución de los suministros comerciales que puedan llegar tan cerca como sea posible del último consumidor, to cual significa probablemente obtener información de los mayoristas. D. Una encuesta de conocimientos, actitudes y prácticas (KAP) para una evaluación general cada dos años. Las preguntas básicas (además de las antes mencionadas y estatus marital y étnico cuando sea pertinente) son: actitud hacia e interés por la anticoncepción, número de niños por sexo, deseo de tener más hijos, prácticas anticonceptivas, experiencia sobre abortos, tal vez historia de embarazo (especialmente si esta producirá una tasa de fecundidad válida), aprobación del programa gubernamental (para uso politico), y si está actualmente embarazada (la única y mejor pregunta cuya respuesta habla del efecto sobre la tasa de natalidad). Administrativamente, la responsabilidad por la evalucion debe estar cerca al director, se debe tomar provisiones para obtener informes regulares (meneulaes) y especiales dirigidos a preguntar sobre política. El corolario es que el jefe de evaluación debe tener la confianza del director y debe estar al día en cuanto a las decisiones sabre la politics a seguir. Su trabajo consiste en extractar los aspectos principales que funcionan bien y los no operantes. En cuanto a costos, la evaluación debe hacerse sobre no más del 10 par ciento del costa del programa en paises pequeños (de menos de 30 milliones) y sabre no más del 5 per ciento en paises más grandes.Para medir en que forma el programa satisface el criterio final-la magnitud en que cambia la fecundidad-se debe realizar un trabajo más elaborado en el centro (Universidades, Consejos de población, etc.) para desarrollar una forma (a formas) segura de traducir las estadísticas de servicio en práticas y tal vez aún datos sobre suministro comercial en datos sabre tasas de natalidad. Esto incluye, par ejemplo, los esfuerzos para consolidar observaciones coma "cinco años-mujer de usa de IUD, a 400 condones equivalen a la prevención de un nacimiento," y esfuerzos como los de Pakistán de calcular tasas coma "años de protección de una pareja contra el embarazo."In the belief that a decrease in the rate of population growth will increase economic development, more than ten countries have inaugurated family planning programs in the past fifteen years. To provide a model for measuring the immediate, intermediate, and long-term effects of any such program, the authors use the Taiwan evaluation.The model suggests that a good system of evaluation should include monthly statistics on (1) participants, who are grouped by characteristics; (2) the distribution of supplies, reported at first by the characteristics of recipients, but after by gross volume only; (3) family planning activities of private physicians to measure the catalytic effect on the private sector; (4) new contacts and amount of advertising in mass media; (5) costs broken down by areas and by cost categories; and (6) distribution of commercial supplies. In addition, the program should conduct 300-400 interviews every 6-12 months to learn the rates of continuation and the rates and reasons for discontinuation. Finally, a KAP survey should be conducted every two years.The administration of the evaluation should be close to the director for policy decisions and for the ultimate work of evaluation-the finding of new ways to measure the main goal of change in fertility by the translation of statistics on Services provided and commercial supplies into birth rate data. PMID:21279762

  18. SIB health psychology in Brazil: The challenges for working in public health settings.

    PubMed

    Spink, Mary-Jane P; Brigagão, Jacqueline M; Menegon, Vera M; Vicentin, Maria-Cristina G

    2016-03-01

    Considering the diversity of theoretical approaches and settings for psychological practice, this editorial provides a background for the articles that have been included in this special issue concerning health psychology in the context of the Brazilian Unified Health System (Sistema Unico de Saude). We addressed issues concerning the national curricular outline for undergraduate training in psychology and historical data on the social movements that led to the creation of the Sistema Unico de Saude and the Psychiatric Reform which created an important area for psychological work absorbing a considerable number of psychologists. PMID:26987822

  19. Voting Systems for Environmental Decisions

    PubMed Central

    BURGMAN, MARK A; REGAN, HELEN M; MAGUIRE, LYNN A; COLYVAN, MARK; JUSTUS, JAMES; MARTIN, TARA G; ROTHLEY, KRIS

    2014-01-01

    Voting systems aggregate preferences efficiently and are often used for deciding conservation priorities. Desirable characteristics of voting systems include transitivity, completeness, and Pareto optimality, among others. Voting systems that are common and potentially useful for environmental decision making include simple majority, approval, and preferential voting. Unfortunately, no voting system can guarantee an outcome, while also satisfying a range of very reasonable performance criteria. Furthermore, voting methods may be manipulated by decision makers and strategic voters if they have knowledge of the voting patterns and alliances of others in the voting populations. The difficult properties of voting systems arise in routine decision making when there are multiple criteria and management alternatives. Because each method has flaws, we do not endorse one method. Instead, we urge organizers to be transparent about the properties of proposed voting systems and to offer participants the opportunity to approve the voting system as part of the ground rules for operation of a group. Sistemas de Votación para Decisiones Ambientales Resumen Los sistemas de votación agregan preferencias eficientemente y muy seguido se usan para decidir prioridades de conservación. Las características deseables de un sistema de votación incluyen la transitividad, lo completo que sean y la optimalidad de Pareto, entre otras. Los sistemas de votación que son comunes y potencialmente útiles para la toma de decisiones ambientales incluyen simple mayoría, aprobación y votación preferencial. Desafortunadamente, ningún sistema de votación puede garantizar un resultado y a la vez satisfacer un rango de criterios de desempeño muy razonable. Además, los métodos de votación pueden manipularse por los que toman las decisiones y votantes estratégicos si tienen el conocimiento de los patrones de votación y de las alianzas entre miembros dentro de las poblaciones votantes. Las propiedades difíciles de los sistemas de votación sobresalen en las tomas de decisiones rutinarias cuando hay criterios múltiples y alternativas de manejo. Ya que ambos métodos tienen fallas, no apoyamos a uno sobre el otro. En lugar de esto le pedimos urgentemente a los organizadores ser transparentes con respecto a las propiedades de los sistemas de votación y ofrecer a los participantes la oportunidad de aprobar el sistema de votación como parte de las reglas básicas para la operación de un grupo. PMID:24423154

  20. Aplicación del Teorema de Nekhorochev para tiempos de estabilidad en Mecánica Celeste

    NASA Astrophysics Data System (ADS)

    Miloni, O.; Núñez, J.; Brunini, A.

    En Mecánica Celeste, uno de los problemas centrales consiste en la determinación de los tiempos de estabilidad. El teorema de Nekhorochev proporciona un método para dicho estudio, para un sistema determinado por un hamiltoniano descripto en las variables acción-ángulo. El trabajo consiste en la acotación tanto del potencial perturbador y de la matriz hessiana del hamiltoniano integrable para determinar luego el tiempo de estabilidad de dicho sistema, donde por estabilidad se entiende la separación en norma infinito en el espacio de las acciones.

  1. Participatory groundwater management in Jordan: Development and analysis of options

    NASA Astrophysics Data System (ADS)

    Chebaane, Mohamed; El-Naser, Hazim; Fitch, Jim; Hijazi, Amal; Jabbarin, Amer

    Groundwater over-exploitation has been on the rise in Jordan. Competing demands have grown in the face of perennial water shortages, a situation which has been exacerbated by drought conditions in the past decade. This paper reports findings of a project in which management options to address over-exploitation were developed for one of Jordan's principal aquifer systems, the Amman-Zarqa Basin. Options for addressing the situation were developed through a participatory approach that involved government officials and various public and private sector interest groups. Particular efforts were made to involve well irrigators, who are likely to be heavily impacted by the changes required to reduce groundwater pumping to a sustainable level. With information obtained from a rapid appraisal survey as well as from interviews with farmers, community groups, government officials, and technical experts, an extensive set of options was identified for evaluation. Based on integrated hydrogeologic, social, and economic analysis, five complementary management options were recommended for implementation. These included the establishment of an Irrigation Advisory Service, buying out farm wells, placing firm limits on well ion and irrigated crop areas, exchanging treated wastewater for groundwater, and measures to increase the efficiency of municipal and industrial water use. Various combinations and levels of these options were grouped in scenarios, representing possible implementation strategies. The scenarios were designed to assist decision makers, well owners and other stakeholders in moving gradually towards a sustainable ion regime. Social and economic aspects of each option and scenario were analyzed and presented to stakeholders, together with a of legal, institutional and environmental ramifications. Combining scientific analysis with a participatory approach in the Amman Zarqa Basin groundwater management was devised as a prototype to be used in the management of other groundwater basins in Jordan. This participatory management approach would also be useful in other parts of the world that are experiencing similar groundwater over-exploitation problems. La surexploitation des eaux souterraines prend de l'importance en Jordanie. Les demandes en concurrence ont augmenté face à des déficits permanents d'eau, situation qui a été exacerbée par la sécheresse de la dernière décennie. Cet article rend compte de l'aboutissement d'un projet dans lequel des options de gestion portant sur la surexploitation ont été développées pour l'un des principaux systèmes aquifères de Jordanie, le bassin d'Amman Zarqa. Des options pour aborder cette situation ont été développées grâce à une approche participative qui implique des fonctionnaires du gouvernement et des groupes d'intérêts variés des secteurs public et privé. Des efforts particuliers ont été faits pour impliquer les irrigants utilisant des puits, qui sont probablement ceux qui ont le plus fort impact sur les changements attendus permettant de remettre le système en équilibre. À partir des informations obtenues de campagnes rapides d'évaluation, telles que des réunions de communautés et des entrevues avec des experts techniques du gouvernement, un large jeu d'options a été identifié pour l'évaluation. Basées sur une analyse hydrogéologique, sociale et économique, cinq options complémentaires de gestion ont été recommandées pour la réalisation. Ce sont la création d'un Service Consultatif d'Irrigation, achetant les puits agricoles, fixant des limites fermes aux prélèvements des puits et aux zones irriguées, échangeant les eaux usées traitées avec des eaux souterraines, et la mise en place de mesures pour accroître l'efficacité des usages collectifs et industriels. Des combinaisons et des niveaux variés de ces options ont été regroupés en scénarios, présentant les stratégies possibles de mise en œuvre. Les scénarios ont été mis au point pour assister les décideurs, les propriétaires de puits et les autres acteurs pour atteindre progressivement un régime de prélèvement durable. Les aspects sociaux et économiques de chaque option et de chaque scénario ont été analysés et présentés aux acteurs, en même temps qu'un résumé des ramifications légales, institutionnelles et environnementales. En combinant une analyse scientifique à une approche participative du bassin d'Amman Zarqa, la gestion des eaux souterraines a été imaginée comme un prototype pouvant être utilisé pour la gestion d'autres bassins aquifères de Jordanie. Il peut également être utile à d'autres régions du monde qui sont concernées par des problèmes similaires de surexploitation des eaux souterraines. La sobreexplotación de las aguas subterráneas ha ido en aumento en Jordania, donde las demandas en competición han crecido frente a una escasez perenne de agua, situación que ha sido agravada por el estado de sequía de la última década. Este artículo presenta los hallazgos de un proyecto en el que se han desarrollado opciones de gestión para hacer frente a la sobreexplotación en uno de los principales sistemas acuíferos de Jordania: la cuenca de Ammán-Zarga. Se ha elaborado opciones para afrontar la situación mediante un enfoque participativo que incluye a personal del gobierno y a diversos grupos de interés de los sectores público y privado. En particular, se ha intentado involucrar a los regantes que se sirven de aguas subterráneas, quienes tienen más probabilidad de ser directamente afectados por los cambios requeridos para devolver el sistema a un balance equilibrado. A partir de la información obtenida en rápidas campañas de valoración, así como de encuentros con la comunidad y entrevistas con los expertos técnicos del gobierno, se ha identificado un amplio conjunto de opciones para su evaluación. Basándose en un análisis integrado de los aspectos hidrogeológicos, sociales y económicos, se ha recomendado la implementación de cinco opciones complementarias de gestión: establecimiento de un Servicio Asesor de Riego; adquisición de pozos de granjas; imposición de límites estrictos en las extracciones de pozos y superficies de riego; substitución de las aguas subterráneas con aguas residuales depuradas; y medidas para incrementar la eficiencia de los usos municipales e industriales del agua. Se ha agrupado varias combinaciones y niveles de dichas opciones en escenarios, representando estrategias posibles de implementación. Los escenarios han sido diseñados para ayudar a los gestores en la toma de decisiones, a los propietarios de pozos y a otros agentes para que se vaya consiguiendo de forma gradual un régimen de extracciones sustentable. Se ha analizado los aspectos sociales y económicos de cada opción y de cada escenario, presentándolos a los diversos agentes, además de generar un resumen de ramificaciones legales, institucionales y medioambientales. Se ha concebido la combinación de un análisis científico con un enfoque participativo en la cuenca de Ammán-Zarga como un prototipo de gestión de las aguas subterráneas que puede ser aplicado a la gestión de otras cuencas en Jordania. También sería útil en otros lugares del mundo que estén experimentando problemas similares de sobreexplotación de los recursos hídricos subterráneos.

  2. Base Lunar Alpha - Duration: 30 seconds.

    NASA Video Gallery

    Tu misión: Recuperar los sistemas críticos cuando un meteoro daña los equipos de supervivencia de tu ambiente lunar. Parece una película de ciencia ficción, ¿verdad? En realidad, es el nuevo juego ...

  3. Agricultural Policy and Child Health in Rural Mexico.

    ERIC Educational Resources Information Center

    Brown, Antoinette B.; Partridge, William L.

    1987-01-01

    Reports on the impact on malnutrition of Mexico's Sistema de Alementacion Mexicana (SAM) program, which tried to make the country self-sufficient in basic foods. Concludes that the food problem in Mexico is not so much one of production as it is a problem of distribution and consumption. (PS)

  4. Costa Rica's SINEM: A Perspective from Postcolonial Institutional Ethnography

    ERIC Educational Resources Information Center

    Rosabal-Coto, Guillermo

    2016-01-01

    In this article I suggest that SINEM--the Costa Rican version of Venezuela's El Sistema--articulates a development discourse which legitimates neoliberal policies that govern the twenty-first-century international market, in which Costa Rica figures only as a subaltern. I contend that such articulation contributes to perpetuating notions and…

  5. The New System for Success

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2012-01-01

    The most ambitious of music teachers seek not only to educate their students about notes and chords, but also to instill in them the transcendent joy of making music. That joy is abundant in Venezuela, where the El Sistema national music education program has been a boon to the country's cultural growth and has created a climate of positive social…

  6. Guanophilic fungi in three caves of southwestern Puerto Rico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fifty species of guanophilic (bat guano-loving) fungi were isolated from field-collected samples within three caves in south-western Puerto Rico; most were mitosporic fungi (23 species). The caves studied were Cueva La Tuna (Cabo Rojo), Cueva de Malano (Sistema de Los Chorros, San Germán), and Cuev...

  7. Costa Rica's SINEM: A Perspective from Postcolonial Institutional Ethnography

    ERIC Educational Resources Information Center

    Rosabal-Coto, Guillermo

    2016-01-01

    In this article I suggest that SINEM--the Costa Rican version of Venezuela's El Sistema--articulates a development discourse which legitimates neoliberal policies that govern the twenty-first-century international market, in which Costa Rica figures only as a subaltern. I contend that such articulation contributes to perpetuating notions and…

  8. Asteroides - Duration: 31 seconds.

    NASA Video Gallery

    Los asteroides son más que una roca metálica que orbita alrededor del sol. Al igual que la Tierra, es posible que Ceres, el asteroide más grande del sistema solar, tenga casquetes polares. Únete a ...

  9. Constructing a New Vision: Undoing Gender through Secondary Education in Honduras

    ERIC Educational Resources Information Center

    Murphy-Graham, Erin

    2009-01-01

    This article presents results from a qualitative study on how the Honduran secondary education programme, "Sistema de Aprendizaje Tutorial" (SAT), attempts to "undo gender" (Deutsch 2007: 122) by encouraging students to rethink gender relations in their everyday lives in a way that reflects their increased consciousness of gender equality. My…

  10. Education Policy Analysis Archives, 2001: Numbers 23-45.

    ERIC Educational Resources Information Center

    Glass, Gene V., Ed.

    2001-01-01

    This document consists of articles 23-45 published in the electronic journal "Education Policy Analysis Archives" for the year 2001: (23) "La Participacion de las Minorias Nacionales dentro de Sistemas Educativas Pre-Modernos: El Caso de los Garifunas de Guatemala" (Carlos R. Ruano); (24) "'Alexander v. Sandoval': A Setback for Civil Rights"…

  11. Two Decades of SIMCE: An Overview of the National Assessment System in Chile

    ERIC Educational Resources Information Center

    Meckes, Lorena; Carrasco, Rafael

    2010-01-01

    The Chilean national learning outcome assessment system (Sistema de Medicion de Calidad de la Educacion, SIMCE) has carried out census-based assessments since 1988 and publishes the results at both the national and school levels. During its 20 years of existence, SIMCE has experienced changes in its institutional framework, objectives,…

  12. The New System for Success

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2012-01-01

    The most ambitious of music teachers seek not only to educate their students about notes and chords, but also to instill in them the transcendent joy of making music. That joy is abundant in Venezuela, where the El Sistema national music education program has been a boon to the country's cultural growth and has created a climate of positive social…

  13. Dinámica de planetas extrasolares resonantes

    NASA Astrophysics Data System (ADS)

    Beauge, C.

    Actualmente se han detectado 117 planetas alrededor de estrellas de Secuencia Principal, incluyendo 12 sistemas planetarios, cada uno con dos o tres miembros. De estos últimos, ocho poseen planetas en órbitas próximas y sus perturbaciones gravitacionales se convierten en un factor fundamental para la estabilidad orbital del sistema. Todos se encuentran en configuraciones resonantes, desde la conmensurabilidad de movimientos 2/1 de Gliese 876, hasta la resonancia secular de Ups And. En esta presentación analizamos varios aspectos de la dinámica resonante de los planetas extrasolares, incluyendo la existencia de soluciones de equilibrio, construcción de modelos analógicos y métodos para la determinación de masas individuales. También discutimos por qué las resonancias son tan frecuentes en estos sistemas, comparado con nuestro propio Sistema Solar. Por último, intentamos relacionar estos modelos con la hipótesis de migración planetaria, buscando límites en su extensión y en los posibles mecanismos que le dieron origen.

  14. Nuevas oportunidades de inmunoterapia dirigida

    Cancer.gov

    Un equipo de investigadores del NCI ha informado que varios tipos de cánceres gastrointestinales tienen mutaciones específicas al tumor que pueden ser reconocidas por el sistema inmunitario, lo que ofrece una posible oportunidad terapéutica para pacientes

  15. Frank Middelburg (1936-1985)

    NASA Astrophysics Data System (ADS)

    Ardeberg, A.

    1985-12-01

    La noticia de la desaparicion de Frank Middelburg, en el dia 15 de Noviembre de 1985, conmovio a tode el mundo astronomico con un sentimiento especial de tristeza. Frank no solo era un experto reconocido en el campo de procesamiento de imagen y un ingeniero de sistemas altamente respetado, tambien era un preciado amigo y colega.

  16. Effect of the Parental Involvement Style Perceived by Elementary School Students at Home on Language and Mathematics Performance in Chilean Schools

    ERIC Educational Resources Information Center

    Gubbins, Verónica; Otero, Gabriel

    2016-01-01

    The present study intends to measure the effect of the parental involvement style perceived by fourth-grade students on their Language and Mathematics performance. It uses data taken from a sample of 55,401 students evaluated by the National Education Quality Measurement System [Sistema Nacional de Medición de la Calidad de la Educación, SIMCE].…

  17. Two Decades of SIMCE: An Overview of the National Assessment System in Chile

    ERIC Educational Resources Information Center

    Meckes, Lorena; Carrasco, Rafael

    2010-01-01

    The Chilean national learning outcome assessment system (Sistema de Medicion de Calidad de la Educacion, SIMCE) has carried out census-based assessments since 1988 and publishes the results at both the national and school levels. During its 20 years of existence, SIMCE has experienced changes in its institutional framework, objectives,…

  18. Energia Renovable para Centros de Salud Rurales (Renewable Energy for Rural Health Clinics)

    SciTech Connect

    Jimenez, T.; Olson, K.

    1999-07-28

    Esta es la primera de una serie de guias de aplicaciones que el Programa de Energia de Villas de NREL esta comisionando para acoplar sistemas comerciales renovables con aplicaciones rurales, incluyendo agua, escuelas rurales y micro empresas. La guia esta complementada por las actividades de desarrollo del Programa de Energia de Villas de NREL, proyectos pilotos internacionales y programas de visitas profesionales.

  19. Examining the benefits of learning based on an audience response system when confronting emergency situations.

    PubMed

    Fernández-Alemán, José Luis; García, Ana Belén Sánchez; Montesinos, María José López; Jiménez, Juan José López

    2014-05-01

    This article presents an empirical study on the effectiveness of the use of an audience response system called SIstema De Respuesta inmediata de la Audiencia on a nursing course. A total of 130 students of mixed gender, age, and computer experience and educational background on a third-year course in nursing administration and management participated in the study. The benefits of an audience response system as regards learning how to confront emergency situations were studied. The innovative aspect of the proposal is twofold: (1) the use of a smartphone to respond to the questions and (2) the analysis of the students' response time when confronting critical situations while managing nursing resources. A positive impact on the students' performance was revealed in their final assessments. Our findings show that SIstema De Respuesta inmediata de la Audiencia increases student participation and aids in identifying and correcting misconceptions. The students found SIstema De Respuesta inmediata de la Audiencia to be very motivating and wanted it to be used in additional lectures. Further research is required to study the effectiveness of SIstema De Respuesta inmediata de la Audiencia for it to be widely used in other disciplines. PMID:24633235

  20. Constructing a New Vision: Undoing Gender through Secondary Education in Honduras

    ERIC Educational Resources Information Center

    Murphy-Graham, Erin

    2009-01-01

    This article presents results from a qualitative study on how the Honduran secondary education programme, "Sistema de Aprendizaje Tutorial" (SAT), attempts to "undo gender" (Deutsch 2007: 122) by encouraging students to rethink gender relations in their everyday lives in a way that reflects their increased consciousness of gender equality. My…

  1. Um estudo espectrofotométrico da variável cataclísmica V3885 Sgr

    NASA Astrophysics Data System (ADS)

    Ribeiro, F. M. A.; Diaz, M. P.

    2003-08-01

    Variáveis Cataclísmicas são sistemas binários cerrados compostos de uma anã vermelha que transfere matéria para uma anã branca, em sistemas não magnéticos ocorre a formação de um disco de acresção em torno da anã branca. V3885 Sgr é uma variável cataclísmica classificada como sendo do tipo nova-like. É apresentado um estudo espectrofotométrico de V3885 Sgr de alta resolução temporal feito na região do visível. A região observada é centrada em Ha e abrange também a linha de HeI 6678. O primeiro resultado obtido neste estudo é a determinação do período orbital a partir de medidas da velocidade radial da linha de Ha como sendo 0,20716071(22) dias, resolvendo inconsistências quanto a esse valor na literatura e definindo uma efeméride a longo prazo para o sistema. Com este período e as medidas de velocidade radial do perfil de linha de Ha foi construído um diagrama de massas, através do qual restringimos as massas das componentes estelares do sistema e limitamos a inclinação orbital do sistema. Foram construídos diagramas de Greenstein para as linhas de Ha e HeI, onde os espectros médios em cada intervalo de fase são representados lado a lado em escala de cinza, indicando a existência de uma emissão intensa proveniente da parte posterior do disco. A partir da tomografia Doppler obtivemos perfis de emissividade radial para o disco tanto para a linha de Ha como para HeI. Os resultados obtidos são comparados com os de outros sistemas estudados com a mesma técnica. Serão apresentados também resultados da tomografia de flickering para o sistema.

  2. Um supressor de fundo térmico para a câmara infravermelha CamIV

    NASA Astrophysics Data System (ADS)

    Jablonski, F.; Laporte, R.

    2003-08-01

    O ângulo sólido subtendido pelos pixels na câmara infravermelha do NexGal (CamIV) que operamos no OPD/LNA contém contribuições provenientes do sistema de coleta de fluxo propriamente dito - sendo esta a parte que interessa para as medidas astronômicas - e contribuições da obstrução central, sistema de suporte do espelho secundário e região exterior à pupila de entrada do telescópio. Estas últimas contribuições são devi-das à emissão de corpo negro à temperatura ambiente e aumentam exponencialmente para comprimentos de onda maiores que 2 micra (banda K, no infravermelho próximo). Embora a resultante pode ser quantificada e subtraída dos sinais relevantes, sua variância se adiciona à variância do sinal, e pode ser facilmente a contribuição domi-nante para a incerteza final das medidas, tornando ineficiente o processo de extração de informação e degradando a sensibilidade da câmara. A maneira clássica de resolver esse problema em sistemas ópticos que operam no infravermelho, onde os efeitos da emissão térmica do ambiente são importantes, é restringir o ângulo sólido subtendido pelos pixels individuais exclusivamente aos raios provenientes do sistema óptico. Para tanto, projeta-se uma imagem real, bastante reduzida, da pupila de entrada do sistema óptico num anteparo que transmita para o sistema de imageamento só o que interessa, bloqueando as contribuições das bordas externas à pupila de entrada, obstrução central do telescópio e sistema de suporte. Como a projeção é realizada em ambiente criogênico, a contribuição térmica espúria é efetivamente eliminada. Nós optamos por um sistema do tipo Offner para implementar na prática esta função. Trata-se de um sistema baseado em espelhos esféricos, bastante compacto e ajustado por construção. A opção por espelhos do mesmo material que o sistema de suporte (Alumínio) minimiza a dilatação diferencial, crítica nesse tipo de aplicação. Apresentamos as soluções detalhadas do projeto óptico-mecânico, bem como uma análise de flexões e desempenho em termos de qualidade de imagem.

  3. La para-osteo-arthropathie neurogene dans le syndrome de guillain barre: complication rare (à propos d'un cas et revue de la littérature)

    PubMed Central

    Abid, Hatim; El Idrissi, Mohamed; Shimi, Mohamed; El Ibrahimi, Abdelhalim; El Mrini, Abdelmajid

    2015-01-01

    Les para-ostéo-arthropathies neurogènes sont des complications classiques des affections neurologiques centrales, surtout dans les contextes traumatiques. Elles surviennent principalement au voisinage des grosses articulations. Leur physiopathologie exacte reste inconnue malgré de très nombreux travaux et cas rapportés. Il semble que leur survenue au décours d'affections neurologiques périphériques soit exceptionnelle. Nous présentons le cas d'une para-ostéo-arthropathie de hanche bilatérale compliquant un syndrome de Guillain-Barré. PMID:26161168

  4. [Sentinel lymph node detection in breast cancer. Experience of the Institut Curie].

    PubMed

    Nos, C; Fréneaux, P; Clough, K B

    2000-05-01

    Sentinel lymph node biopsy is a recently developed, minimally invasive technique for staging the axilla in breast cancer. This new procedure of selective lymphadenectomy has been the subject of several studies, and a consensus of opinion is starting to form to define indications and methods of identification concerning the use of this technique. At the Institut Curie since 1996, we have been using the Patenté blue dye technique and from 1998 we have used the combination of blue dye and technetium labeled sulfur colloid. This article summarizes the principales aspect of this technique. PMID:10804363

  5. L'Aventure du LHC

    ScienceCinema

    None

    2011-10-06

    Cette présentation s?adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l?engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  6. Curvas de rotación - Atlas

    NASA Astrophysics Data System (ADS)

    Martín, C.

    Se está elaborando un atlas con imágenes y datos publicados en las revistas principales por diversos autores, de las curvas de rotación en galaxias observadas en diferentes frecuencias. Las curvas de rotación constituyen uno de los medios más apropiados para el estudio de las diferencias cinemáticas entre los diversos componentes y quizá la mejor prueba observacional de la existencia de materia oscura en el universo. Este atlas tiene el propósito de servir como una guía cualitativa y cuantitativa para estos estudios.

  7. Transcendental Meditation

    SciTech Connect

    2005-11-29

    K.Wallace, qui vient des Etats Unis, parle des effects physiologiques de la méditation transcendantale. Il a fait son bachelor en physique à l'Université de Los Angeles et son doctorat en physiologie aussi à Los Angeles, mais à l'Institut de Recherche sur le cerveau. Il travaille maintenat à Harvard Medical School ou il continue des recherches biochimiques et physiologiques sur l'application médicale de la méditation transcendantale. Il s'occupe principalement des maladies cardiaques et de hypertension artérielle.

  8. Le syndrome de Budd-Chiari: une complication rare de la sarcoïdose hépatique (à propos d'un cas)

    PubMed Central

    Sghier, Ismael Ait; Billah, Nabil Moatassim

    2016-01-01

    L'atteinte hépatique au cours de la sarcoïdose est une localisation fréquente, habituellement asymptomatique. La cholestase anictérique et l'hypertension portale représentent ses principales complications. Le syndrome de Budd-Chiari est une complication peu connue qui demeure exceptionnelle. Nous rapportons un nouveau cas de syndrome de Budd-Chiari compliquant une sarcoïdose hépatique chez une jeune femme de 45 ans. PMID:27200114

  9. L'Aventure du LHC

    SciTech Connect

    2010-06-11

    Cette présentation s’adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l’engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  10. Kyste dermoïde géant de la paroi abdominale: une observation rare

    PubMed Central

    Yaka, Mbarek; Ehirchiou, Abdelkader; Alkandry, Sifeddine; Zentar, Aziz

    2015-01-01

    Les kystes dermoïdes sont des lésions bénignes fréquentes. Ils peuvent être volumineux et entrainer une destruction des tissus avoisinants surtout au niveau du crâne. Ces kystes dermoïdes sont le plus souvent de localisation ovarienne ou testiculaire mais d'autres localisations, principalement axiales, sont décrites. Le kyste dermoïde de la paroi abdominale est rare. Quant aux volumineux kystes, ils sont encore plus rares. La possibilité de leur dégénérescence impose une exérèse chirurgicale. Nous rapportons un cas rare de kyste dermoïde géant de la paroi abdominale antérolatérale, qui peut poser un problème de diagnostic différentiel avec le un kyste hydatique, surtout dans un pays endémique comme le Maroc. PMID:26327968

  11. Formación y evolución de planetas gigantes

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; Brunini, A.

    Presentamos el estado actual del trabajo que estamos realizando en el estudio de la formación de planetas gigantes. Detallamos los algoritmos numéricos necesarios para realizar este tipo de cálculo. Presentamos algunos resultados de la formación de objetos con masas de hasta una docena de veces la del planeta Júpiter, resaltando las principales caracteríticas. Finalmente detallamos los problemas que pensamos abordar en un futuro cercano en este tema de investigación.

  12. Transcendental Meditation

    ScienceCinema

    None

    2011-04-25

    K.Wallace, qui vient des Etats Unis, parle des effects physiologiques de la méditation transcendantale. Il a fait son bachelor en physique à l'Université de Los Angeles et son doctorat en physiologie aussi à Los Angeles, mais à l'Institut de Recherche sur le cerveau. Il travaille maintenat à Harvard Medical School ou il continue des recherches biochimiques et physiologiques sur l'application médicale de la méditation transcendantale. Il s'occupe principalement des maladies cardiaques et de hypertension artérielle.

  13. Educación no formal

    NASA Astrophysics Data System (ADS)

    Tignanelli, H.

    Se comentan en esta comunicación, las principales contribuciones realizadas en el campo de la educación en astronomía en los niveles primario, secundario y terciario, como punto de partida para la discusión de la actual inserción de los contenidos astronómicos en los nuevos contenidos curriculares de la EGB - Educación General Básica- y Polimodal, de la Reforma Educativa. En particular, se discuten los alcances de la educación formal y no formal, su importancia para la capacitación de profesores y maestros, y perspectivas a futuro.

  14. Velocidades radiales de estrellas gigantes rojas y blue stragglers en cúmulos abiertos

    NASA Astrophysics Data System (ADS)

    González, J. F.; Lapasset, E.

    Se presentan mediciones de las estrellas más brillantes en los campos de los cúmulos abiertos NGC 6530, NGC 2516, NGC 3114, Cr 223 y NGC 2437. Mediante correlaciones cruzadas se obtiene la velocidad de unas 25 gigantes rojas con el objeto de derivar la velocidad media de cada asociación. En base a los espectros obtenidos de los blue stragglers se discuten sus principales características y su probabilidad de pertenencia. Finalmente, se presentan las observaciones para cinco nuevas binarias espectroscópicas detectadas.

  15. L'effet Casimir : théorie et expériences

    NASA Astrophysics Data System (ADS)

    Lambrecht, A.; Genet, C.; Intravaia, F.; Reynaud, S.

    2004-11-01

    L'existence de fluctuations irréductibles de champ dans le vide est une prédiction importante de la théorie quantique. Ces fluctuations ont de nombreuses conséquences observables comme l'effet Casimir, qui est maintenant mesuré avec une bonne précision et un bon accord avec la théorie, pourvu que celle-ci tienne compte des différences entre les expériences rélles et la situation idéale considérée par H.G.B. Casimir. Nous présenterons quelqu'unes des expériences récentes et discuterons les principales corrections à la force de Casimir liées à la situation expérimentale.

  16. Association rare d'un adenome pleomorphe et d'un carcinome epithelial myoepithelial de la glande parotide

    PubMed Central

    Jahidi, Ali; Hemmaoui, Bouchaib; Noureddine, Errami; Youssef, Darouassi; Issam, Rharrasi; Hafsa, Chahdi; Benariba, Fouad

    2014-01-01

    Le Carcinome épithélial - myoépithélial (CEM) est une tumeur maligne rare des glandes salivaires touchant principalement la glande parotide. Son association avec un adénome pléomorphe est exceptionnelle. Nous rapportons le cas d'une femme de 57 ans avec adénome pléomorphe de la glande parotide évoluant depuis plusieurs années. L'augmentation récente du volume de la glande associée à l'apparition d'adénopathies cervicales homolatérales nous a fait penser à une transformation maligne. L'examen histologique final après parotidectomie totale a montré une association inattendue d'un adénome pléomorphe et un CEM. Le CEM est une tumeur maligne de bas grade. Elle peut survenir de novo ou sur un adénome pléomorphe. La transformation maligne de l'adénome est suspectée devant l'augmentation rapide du volume de l'adénome avec apparition d'adénopathies cervicales. Toutefois, ces modifications cliniques peuvent annoncer l'apparition d'une tumeur distincte. Malgré sa tendance à la récidive locale et un faible potentiel métastatique, de rares cas de CEM peuvent avoir un comportement agressif et des métastases à distance. Le traitement consiste principalement en une résection chirurgicale complète si possible suivie d'une radiothérapie dans le but de prévenir la récidive locale. PMID:25368716

  17. Modos de produccion cientifica: Culturas y metodologias de investigacion en la Universidad de Cadiz

    NASA Astrophysics Data System (ADS)

    Gonzalez Ramos, Ana M.

    2004-12-01

    Este trabajo de investigacion supone un modelo teorico de caracter aplicado, que proporciona la oportunidad de evaluar la produccion cientifica de los investigadores. Se encuadra dentro de la tradiccion de la estadistica aplicada y la sociologia del conocimiento. Atiende especialmente a dos conjuntos de temas de interes, por una parte, las caracteristicas principales que determinan el nivel y tipo de produccion academica producida por las unidades de investigacion y por los propios investigadores; por otra, la utilizacion que se hace de los metodos y tecnicas de investigacion puesto que de ello tambien depende el modo de produccion cientifica. Los puntos novedosos de esta tesis son: la medicion cuantitativa del objeto de estudio, la suma de los productos y las condiciones externas a la produccion del conocimiento mas otros elementos internos como las caracteristicas de los investigadores y la metodologia utilizada para desarrollar sus trabajos; y, finalmente, el uso de las nuevas tecnologias. El aprovechamiento de los recursos estadisticos y las fuentes de informacion secundarias se complementan con el diseno propio de una encuesta donde se implementa las caracteristicas descritas en un capitulo anterior sobre los metodos cientificos mas idoneos descritos en los principales manuales y articulos cientificos desde distintas disciplinas de conocimiento. Dicha encuesta ha sido desarrollada como un programa propio y en base a los mas innovadores usos de la tecnologia en la metodologia de encuestas.

  18. Efficient Aho-Corasick String Matching on Emerging Multicore Architectures

    SciTech Connect

    Tumeo, Antonino; Villa, Oreste; Secchi, Simone; Chavarría-Miranda, Daniel

    2013-12-12

    String matching algorithms are critical to several scientific fields. Beside text processing and databases, emerging applications such as DNA protein sequence analysis, data mining, information security software, antivirus, ma- chine learning, all exploit string matching algorithms [3]. All these applica- tions usually process large quantity of textual data, require high performance and/or predictable execution times. Among all the string matching algorithms, one of the most studied, especially for text processing and security applica- tions, is the Aho-Corasick algorithm. 1 2 Book title goes here Aho-Corasick is an exact, multi-pattern string matching algorithm which performs the search in a time linearly proportional to the length of the input text independently from pattern set size. However, depending on the imple- mentation, when the number of patterns increase, the memory occupation may raise drastically. In turn, this can lead to significant variability in the performance, due to the memory access times and the caching effects. This is a significant concern for many mission critical applications and modern high performance architectures. For example, security applications such as Network Intrusion Detection Systems (NIDS), must be able to scan network traffic against very large dictionaries in real time. Modern Ethernet links reach up to 10 Gbps, and malicious threats are already well over 1 million, and expo- nentially growing [28]. When performing the search, a NIDS should not slow down the network, or let network packets pass unchecked. Nevertheless, on the current state-of-the-art cache based processors, there may be a large per- formance variability when dealing with big dictionaries and inputs that have different frequencies of matching patterns. In particular, when few patterns are matched and they are all in the cache, the procedure is fast. Instead, when they are not in the cache, often because many patterns are matched and the caches are continuously thrashed, they should be retrieved from the system memory and the procedure is slowed down by the increased latency. Efficient implementations of string matching algorithms have been the fo- cus of several works, targeting Field Programmable Gate Arrays [4, 25, 15, 5], highly multi-threaded solutions like the Cray XMT [34], multicore proces- sors [19] or heterogeneous processors like the Cell Broadband Engine [35, 22]. Recently, several researchers have also started to investigate the use Graphic Processing Units (GPUs) for string matching algorithms in security applica- tions [20, 10, 32, 33]. Most of these approaches mainly focus on reaching high peak performance, or try to optimize the memory occupation, rather than looking at performance stability. However, hardware solutions supports only small dictionary sizes due to lack of memory and are difficult to customize, while platforms such as the Cell/B.E. are very complex to program.

  19. Unified QSAR approach to antimicrobials. 4. Multi-target QSAR modeling and comparative multi-distance study of the giant components of antiviral drug-drug complex networks.

    PubMed

    Prado-Prado, Francisco J; Martinez de la Vega, Octavio; Uriarte, Eugenio; Ubeira, Florencio M; Chou, Kuo-Chen; González-Díaz, Humberto

    2009-01-15

    One limitation of almost all antiviral Quantitative Structure-Activity Relationships (QSAR) models is that they predict the biological activity of drugs against only one species of virus. Consequently, the development of multi-tasking QSAR models (mt-QSAR) to predict drugs activity against different species of virus is of the major vitally important. These mt-QSARs offer also a good opportunity to construct drug-drug Complex Networks (CNs) that can be used to explore large and complex drug-viral species databases. It is known that in very large CNs we can use the Giant Component (GC) as a representative sub-set of nodes (drugs) and but the drug-drug similarity function selected may strongly determines the final network obtained. In the three previous works of the present series we reported mt-QSAR models to predict the antimicrobial activity against different fungi [Gonzalez-Diaz, H.; Prado-Prado, F. J.; Santana, L.; Uriarte, E. Bioorg.Med.Chem.2006, 14, 5973], bacteria [Prado-Prado, F. J.; Gonzalez-Diaz, H.; Santana, L.; Uriarte E. Bioorg.Med.Chem.2007, 15, 897] or parasite species [Prado-Prado, F.J.; González-Díaz, H.; Martinez de la Vega, O.; Ubeira, F.M.; Chou K.C. Bioorg.Med.Chem.2008, 16, 5871]. However, including these works, we do not found any report of mt-QSAR models for antivirals drug, or a comparative study of the different GC extracted from drug-drug CNs based on different similarity functions. In this work, we used Linear Discriminant Analysis (LDA) to fit a mt-QSAR model that classify 600 drugs as active or non-active against the 41 different tested species of virus. The model correctly classifies 143 of 169 active compounds (specificity=84.62%) and 119 of 139 non-active compounds (sensitivity=85.61%) and presents overall training accuracy of 85.1% (262 of 308 cases). Validation of the model was carried out by means of external predicting series, classifying the model 466 of 514, 90.7% of compounds. In order to illustrate the performance of the model in practice, we develop a virtual screening recognizing the model as active 92.7%, 102 of 110 antivirus compounds. These compounds were never use in training or predicting series. Next, we obtained and compared the topology of the CNs and their respective GCs based on Euclidean, Manhattan, Chebychey, Pearson and other similarity measures. The GC of the Manhattan network showed the more interesting features for drug-drug similarity search. We also give the procedure for the construction of Back-Projection Maps for the contribution of each drug sub-structure to the antiviral activity against different species. PMID:19112024

  20. Estructura espacial de las órbitas caóticas en un modelo autoconsistente de galaxia elíptica

    NASA Astrophysics Data System (ADS)

    Muzzio, J. C.

    Hemos logrado construir modelos autoconsistentes de sistemas estelares utilizando una aproximación cuadrupolar para el potencial. Esto nos permite determinar órbitas y exponentes de Lyapunov de objetos que tienen posiciones y velocidades equivalentes a las que se obtienen de la funcón de distribución del sistema. La distribución espacial de las órbitas caóticas exhibe considerable estructura y, lo que es más importante aún, los valores de los exponentes de Lyapunov calculados sobre intervalos finitos de tiempo, muestran una fuerte correlación con el comportamiento de la órbita en esos mismos intervalos, por lo que permiten reconocer distintos subsistemas con diferentes distribuciones espaciales.

  1. Polarización lineal en estrellas simbióticas

    NASA Astrophysics Data System (ADS)

    Brandi, E.; García, L. G.; Ferrer, O. E.

    Se presenta un estudio de polarización lineal en las bandas UBVRI de un grupo de estrellas simbióticas, a fin de analizar el comportamiento del grado de polarización y del ángulo de posición en función de la longitud de onda. En aquellos sistemas observados repetidas veces, se analizan además variaciones temporales en los parámetros de polarización. En base a este comportamiento se determina si la polarización observada es puramente interestelar o si existe una contribución de polarización, intrínseca al objeto. La muestra de objetos estudiados presenta ciertas características comunes, es decir, son sistemas simbióticos tipo D, cuyas respectivas componentes gigantes son variables tipo Mira y además presentan nebulosas ionizadas extendidas con morfología y dimensiones conocidas. Esto es de importancia ya que el conocimiento de la estructura del gas extendido permite interpretar la geometría de scattering que produce la polarización observada. Las observaciones fueron realizadas con el Fotopolarímetro de Torino adosado al telescopio de 2.15 m del CASLEO.

  2. Dinámica global en galaxias elípticas

    NASA Astrophysics Data System (ADS)

    Pérez, M. J.; Cincotta, P. M.; Giordano, C. M.

    Con el propósito de determinar propiedades dinámicas globales en sistemas triaxiales no integrables, utilizamos una nueva herramienta conocida como ``Mean Exponential Growth factor of Nearby Orbits'' (MEGNO), introducida por Cincotta y Simó (2000). Esta técnica no sólo resulta eficiente para investigar ambas componentes del espacio fase, regular y caótica, sino que también, provee una medida de la hiperbolicidad en el dominio caótico que coincide con la dada por el Lyapunov Characteristic Number (LCN). Previamente este método ha sido aplicado al estudio de modelos simples, y últimamente en el campo de la Mecánica Celeste, al estudio de sistemas planetarios extrasolares. En esta presentación, ilustraremos algunas de las propiedades más importantes del MEGNO, aplic& acute;andolo al potencial tridimensional de Stäckel perturbado.

  3. Estabilidad de los modelos de Heggie y Ramamani

    NASA Astrophysics Data System (ADS)

    Muzzio, J. C.; Vergne, M. M.; Wachlin, F. C.; Carpintero, D. D.

    Los modelos de Heggie y Ramamani de satélites galácticos en órbitas circulares se basan en una teoría aproximada, por lo que es importante verificar su estabilidad mediante simulaciones numéricas. En esta forma, hemos logrado mostrar que son estables sobre intervalos de tiempo mucho mayores que los que lograron los propios autores de los modelos. Por otra parte, dado que hemos mostrado que el caos es significativo en estos modelos, son un sistema ideal para investigar si, pese a ello, se mantienen estacionarios. Nuestras simulaciones numéricas muestran que, pese al caos, la estacionariedad se mantiene sobre intervalos de centenares de tiempos de cruce del sistema, mucho mayores que los tiempos de Liapunov característicos de sus movimientos caóticos.

  4. Determinación de la orientación global SAO-Hipparcos mediante una expansión en armónicos vectoriales

    NASA Astrophysics Data System (ADS)

    Cionco, R. G.; Vucetich, H.; Orellana, R.; Arias, E. F.

    En base a las diferencias de posición y movimientos propios de 101352 estrellas con posición SAO observadas por HIPPARCOS y utilizando la naturaleza vectorial de esas diferencias, determinamos 6 parámetros de orientación global (3 de rotación y 3 de desplazamiento axial), para los sistemas de referencia asociados a los marcos mencionados, mediante una descomposición en serie de armónicos vectoriales ortogonales.

  5. Digestive Diseases - Multiple Languages: MedlinePlus

    MedlinePLUS

    ... PDF Health Information Translations Spanish (español) Enfermedades del sistema digestivo Ukrainian (Українська) EGD (Endogastroduodenoscopy) ЕГД (Ендогастродуоденоскопія) - Українська ( ...

  6. Guilherme Rodrigues da Silva: the development of the field of collective health in Brazil.

    PubMed

    Goldbaum, Moisés

    2015-07-01

    This article describes the academic trajectory of Professor Guilherme Rodrigues da Silva and his contribution in the formation of Collective Health in Brazil. Three key aspects are covered: active participation in medical education, both undergraduate and graduate level; its application in scientific research for the study of neglected diseases and the development of epidemiological methodology; his contribution in establishing health policy with emphasis on the Unique Health System (Sistema Único de Saúde - SUS). PMID:26132252

  7. Mecânica celeste.

    NASA Astrophysics Data System (ADS)

    de Luca, N.; Ferraz-Mello, S.

    Contents: Os princípios da mec@OSC@@CCF@anica celeste. O problema de 2-corpos. O sistema de equações canônicas. A teoria das perturbações. O movimento de um satélite artifical. A teoria lunar e o movimento de outros satélites naturais. A teoria planetária. Procedimentos numéricos.

  8. La distribución multimodal de cúmulos globulares en la galaxia NGC 1399

    NASA Astrophysics Data System (ADS)

    Forte, J. C.; Ostrov, P. G.

    Se presenta una discusión de las características del diagrama de dos colores para un muestreo de 400 cúmulos globulares asociados con NGC 1399. Los resultados indican la presencia de, por lo menos, tres familias de cúmulos. La naturaleza de una cuarta componente, muy azul, no es clara aunque podría tratarse de cúmulos ``sueltos" asociados con el sistema de Fornax.

  9. Entropía de la información: una herramienta útil

    NASA Astrophysics Data System (ADS)

    Cincotta, P.

    En este trabajo se presenta una muy breve introducción al concepto de Entropía de la Información y se muestran distintas aplicaciones de una misma técnica para estudiar problemas tan variados como la determinación de periodicidad en una serie de tiempo arbitraria o de estimar el grado de caoticidad de una trayectoria en un sistema dinámico de N grados de libertad.

  10. Fotometría de Asteroides

    NASA Astrophysics Data System (ADS)

    Gil Hutton, R.; Cañada, M.; Coldwell, G.

    Se presentan observaciones fotométricas de asteroides realizadas desde la Estación Astronómica Dr. Carlos Ulrrico Cesco durante el primer semestre de 1997. Para dos objetos se presentan por primera vez las correspondientes curvas de luz y se muestran también resultados de pruebas realizadas en el telescopio astrográfico doble a los efectos de testear el sistema con vista a la instalación a de un nuevo equipo detector.

  11. The Model of Optimization of Micro Energy; HOMER: El Modelo de Optimizacin de Micro energa

    SciTech Connect

    Not Available

    2004-05-01

    HOMER, the model of optimization of micro energy, helps to disear systems out of the network and interconnected to the network. You can use HOMER to carry out the analysis to explore an extensive rank of questions of diseo. HOMER, el modelo de optimizacin de micro energa, le ayuda a disear sistemas fuera de la red e interconectados a la red. Usted puede usar HOMER para llevar a cabo el anlisis para explorar un amplio rango de preguntas de diseo.

  12. How Do Management Fees Affect Retirement Wealth under Mexico's Personal Retirement Accounts System?

    PubMed Central

    Aguila, Emma; Hurd, Michael D.; Rohwedder, Susann

    2014-01-01

    In 1997, Mexico transformed its pay-as-you-go social security system to a fully funded system with personal retirement accounts, including management fees. This article examines changes in retirement wealth resulting from this new system. It shows that management fees have drained a significant proportion of individuals' retirement wealth and have increased the number of persons claiming a government-subsidized minimum pension, particularly from the time the system was introduced in 1997 until adjustment to management fees in 2008. Since 2008, retirement wealth accumulation has been similar to that of the previous system. En 1997, México transformó su sistema de pensiones basado en cotizaciones individuales a uno de ahorro para el retiro que incluyen cuotas por la administración de las cuentas. El presente estudio examina los cambios en el monto de las pensiones como resultado de la introducción del nuevo sistema. Los resultados muestran que las cuotas de administración han drenado una proporción significativa del ahorro para el retiro de los individuos por lo que ha aumentado el número de personas que solicita la pensión mínima garantizada subsidiada por el gobierno desde que se introdujo el sistema en 1997 hasta que se hicieron ajustes en las cuotas de administración de los fondos de pensiones en 2008. A partir de 2008, la acumulación del ahorro para el retiro ha sido similar que la del sistema anterior. PMID:25601893

  13. El nuevo panorama de la Dinámica Galáctica

    NASA Astrophysics Data System (ADS)

    Pivovaroff, Michael James

    En general, la tendencia imperante en Dinámica Galáctica ha sido considerar que los movimientos estelares son básicamente regulares y que el caos no tiene mayor relevancia en los sistemas estelares. Sin embargo, en el último lustro se vienen acumulando pruebas de la importancia del movimiento caótico en ciertos sistemas estelares que existen en la naturaleza. Por una parte, sobre todo el grupo de David Merritt, lo ha mostrado en los casos de galaxias elípticas con concentraciones centrales de materia; por otra parte, en nuestro propio grupo, lo hemos mostrado para el caso de los satélites galácticos. Las consecuencias de estos hallazgos son tanto de tipo técnico, por la necesidad de construir modelos que contengan órbitas caóticas, como astrofísico, por los efectos del caos sobre la estacionariedad y evolución de los sistemas estelares en los que se presenta.

  14. Imagens do céu ontem e hoje - um multimídia interativo de astronomia e uma nova exposição no MAST

    NASA Astrophysics Data System (ADS)

    Caretta, C. A.; Lima, F. P.; Requeijo, F.; Vieira, G. G.; Alves, F.; Valente, M. E. A.; de Almeida, R.; de Garcia, G. C.; Quixadá, A. C.

    2003-08-01

    "Imagens do Céu Ontem e Hoje" é o título de uma nova exposição que está sendo inaugurada no Museu de Astronomia e Ciências Afins (MCT), que inclui experimentos interativos, maquetes, réplicas e 8 terminais de computador com um multimídia interativo sobre Astronomia para consulta dos visitantes. O multimídia apresenta um conteúdo bastante extenso, que engloba quase todos os temas em Astronomia, consistindo numa fonte de divulgação e pesquisa para um público que vai das crianças até estudantes universitários. O conteúdo está distribuído em mais de 500 páginas de texto divididas em 4 módulos: "O Universo", "Espectroscopia", "Telescópios" e "Observando o Céu". Cada módulo é subdividido em 5 seções, em média, cada uma iniciada por uma animação que ilustra os temas a serem abordados na seção. Ao final da animação, uma lista de temas é apresentada sob o título "Saiba Mais". Para exemplificar, o módulo "O Universo" contém as seguintes seções: "O Universo visto pelo homem", "Conhecendo o Sistema Solar", "Indo além do Sistema Solar", "Nossa Galáxia, a Via-Láctea" e "Indo mais além, a imensidão do Universo". A seção "Conhecendo o Sistema Solar", por sua vez, tem os seguintes temas: "A origem do Sistema Solar", "O Sol", "Os planetas", "Satélites, asteróides, cometas e outros bichos..." e "O Sistema Solar em números". Cada texto é repleto de imagens, quadros, desenhos, esquemas, etc, além de passatempos ao final de cada seção, incluindo jogos interativos, quadrinhos e curiosidades, que auxiliam o aprendizado de forma divertida. Apresentamos neste trabalho as idéias gerais que permearam a produção da exposição, e uma viagem pelo multimídia para exemplificar sua estrutura e conteúdo. O multimídia será posteriormente disponibilizado para o público externo pela página eletrônica do MAst e/ou por intermédio de uma publicação comercial.

  15. Proprietes ionochromes et photochromes de derives du polythiophene

    NASA Astrophysics Data System (ADS)

    Levesque, Isabelle

    La synthese et la caracterisation de derives regioreguliers du polythiophene ont ete effectuees en solution et sur des films minces. La spectroscopie UV-visible de ces derives a permis de constater qu'ils peuvent posseder des proprietes chromiques particulieres selon le stimulus auquel ils sont soumis. Par exemple, une augmentation de la temperature permet en effet aux polymeres de passer d'une couleur violette a jaune, et ce, a l'etat solide aussi bien qu'en solution. Ces proprietes chromiques semblent regies par une transition conformationnelle (plane a non-plane) de la chaine principale. Ce travail avait pour but de mieux comprendre l'influence de l'organisation des chaines laterales sur les transitions chromiques. Deux derives synthetises possedant des chaines laterales sensibles aux cations alcalins se sont averes etre ionochromes en plus d'etre thermochromes. Il s'agit d'un polymere comportant des chaines laterales de type oligo(oxyethylene) et d'un autre comportant un groupement ether couronne specifique aux ions lithium. Les effets chromiques observes sont expliques par des interactions non-covalentes des cations avec les atomes d'oxygene des chaines laterales dans le cas du premier polymere, et par l'insertion de l'ion Li + dans la cavite de l'ether couronne dans le cas du second polymere. Ces interactions semblent provoquer une diminution de l'organisation induisant ainsi une torsion de la chaine principale. Les deux polymeres semblent specifiques a certains cations et pourraient donc servir comme detecteurs optiques. La specificite aux ions Li+ du second polymere pourrait aussi permettre la conduction ionique, en plus de la conductivite electronique caracteristique des polythiophenes, ce qui pourrait s'averer utile dans le cas de batteries legeres entierement faites de polymeres et de sels de lithium. D'autres derives comportant des chaines laterales de type azobenzene se sont averes etre photochromes en plus d'etre thermochromes. Le groupement lateral a la possibilite de changer de configuration de la forme trans a la forme cis lorsqu'il est soumis a une irradiation dans le domaine de l'ultraviolet ce qui provoque, selon toute evidence, un effet marque sur l'organisation des chaines laterales. Cela induit alors une torsion de la chaine principale thiophene entrainant une diminution de conjugaison marquee. Ces effets peuvent etre exploites entre autres dans l'ecriture optique. Il s'est avere que le polymere irradie peu conjugue peut etre force a retourner a son etat initial conjugue tres rapidement par un traitement electrochimique simple. En conclusion, on a pu prouver qu'une modification dans l'organisation des chaines laterales par un stimulus exterieur affecte considerablement la conformation de la chaine principale. Cela porte a croire que les chaines laterales stabilisent une conformation particuliere des polythiophenes.

  16. Fenómenos solares que afectan la atmósfera terrestre

    NASA Astrophysics Data System (ADS)

    Rovira, M.

    Se describen los principales fenómenos solares como fulguraciones, prominencias eruptivas, viento solar y eyecciones de masa coronal (CME) que tienen consecuencias en la atmósfera terrestre. En algunos casos el material es eyectado a velocidades superiores a los 900 km/seg y tarda menos de 48 horas en llegar a la Tierra. En general, estos CME no son peligrosos ya que el campo magnético terrestre actúa como protector siendo un aislante efectivo. Si el viento solar es muy intenso puede comprimir la magnetósfera y producir una tormenta geomagnética. En casos extremos, puede interferir la transmisión de potencia eléctrica, perturbar los satélites y producir auroras polares.

  17. Une cause rare du choc septique chez le diabétique: la cystite emphysémateuse compliquée d'une rupture vésicale

    PubMed Central

    Shimi, Abdelkarim; Boumedian, Abderrahman; Elbakouri, Nabil; Derkaoui, Ali; Khatouf, Mohammed

    2015-01-01

    La cystite emphysémateuse est une affection rare rencontrée principalement chez les patients diabétiques mal équilibrés. Elle se caractérise par la présence de l'air dans la paroi et/ou la lumière vesicale. La tomodensitométrie abdomino-pelvienne reste l'examen clé pour confirmer le diagnostic. Nous rapportons l'observation d'une patiente diabétique ayant présentée une cystite emphysémateuse favorisée par un diabète déséquilibré et compliquée d'une rupture vésicale intrapéritonéale avec évolution défavorable. PMID:26301019

  18. Maladie d'Aïnhum (dactylolyse spontanée) : à propos d'un cas Clinique

    PubMed Central

    Maruis, Kitembo Feruzi; Cédrick, Sangwa Milindi; Mireille, Kakinga Zabibu; Felix, Mutomb Jean

    2014-01-01

    La vraie maladie d'Aïnhum est est une pathologie d’étiologie inconnue, associée à une bande de constriction autour du cinquième orteil, principalement chez les adultes de peau noire en milieu tropical. Le terme Pseudoaïnhum désigne les autres formes de constriction des doigts et orteils. Les cas de Pseudoaïnhum sont de plus en plus décrits dans la littérature. Nous présentons ici un cas de la maladie d'Aïnhum reçu au stade III de la pathologie et qui a bénéficié d'une amputation du cinquième orteil. PMID:25667722

  19. Estudio de la galaxia peculiar NGC 1487

    NASA Astrophysics Data System (ADS)

    Agüero, E. L.; Paolantonio, S.; Gunthardt, G.

    La galaxia peculiar NGC 1487, cuya morfología sugiere un evento de ``merging" o interacción próxima, es estudiada en base a material observacional espectroscópico y fotométrico obtenido en el CASLEO. Mediante técnicas espectrofotométricas standards se determinan las principales características espectrales, los mecanismos de excitación actuantes, las condiciones físicas y las velocidades radiales de las estructuras conspicuas de la galaxia. Por otra parte, usando imágenes directas en las bandas B, V, R e I, se obtienen distribuciones detalladas de los colores B-V, V-R y R-I y detalles de su morfología.

  20. Les résultats de la photomé̀trie.

    NASA Astrophysics Data System (ADS)

    Mignard, F.; Falin, J. L.

    Le traitement des comptages recueillis par le détecteur de Hipparcos permet de déterminer la magnitude des sources observées. Ce rapport donne des informations touchant à la photométrie effectuée avec le détecteur de la grille principale de Hipparcos, et exclu donc les mesures de couleurs du repéreur d'étoiles. Les 118000 étoiles du programme ont été observées chacune en moyenne 120 fois au cours de la mission. Une base photométrique de 14 millions d'observations sera mise à la disposition de la communauté scientifique en me^me temps que les résultats astrométriques.

  1. Que peut-on voir avec des neutrons? Une introduction pour des non spécialistes

    NASA Astrophysics Data System (ADS)

    Schweizer, J.

    2005-11-01

    Le neutron est une particule élémentaire qui a été découverte en 1932 par James Chadwick. Ses caractéristiques principales sont résumées dans le tableau I. Il a été utilisé pour la première fois par Clifford Shull en 1946 comme outil pour des expériences de diffusion. Cette technique s'est depuis constamment développée pour concerner tous les aspects de la matière condensée: physique, chimie, matériaux, biologie. Il s'agit d'un outil tout à fait exceptionnel car le neutron possède des propriétés uniques et particulièrement adaptées pour ces études.

  2. Systeme Optique de Transformations de Coordonnees et Son Utilisation EN Reconnaissance de Formes

    NASA Astrophysics Data System (ADS)

    Asselin, Daniel

    La foramtion optique des transformations de coordonnees (TC) polaire et log-polaire a un grand potentiel en reconnaissance invariante sous rotation et changement d'echelle en temps reel. Cependant, jusqu'ici, la faible qualite des transformations obtenues et le probleme d'enroulement ont empeche toute utilisation pratique. A l'aide d'hologrammes a facettes generes par ordinateur, nous etudierons donc la generation optique de TC de qualite en utilisant des facettes de tailles variables tandis que, en juxtaposant deux TC, nous reduirons de facon appreciable l'effet d'enroulement. Suite a ces ameliorations, nos experiences demontreront la possibilite d'une reconnaissance invariante en rotation et en echelle d'objets simples, seule l'etape de la classification etant supportee numeriquement. Nous etudierons egalement les effets, sur l'onde reconstruite, de la resolution limitee du modulateur supportant l'hologramme, les principales conclusions ayant ete experimentalement confirmees.

  3. L’érysipèle sur cicatrice post opératoire en traumatologie: à propos d'un cas et revue de la littérature

    PubMed Central

    Abid, Hatim; El Idrissi, Mohamed; Shimi, Mohamed; El Ibrahimi, Abdelhalim; El Mrini, Abdelmajid; Amraoui, Nissrine; Mernissi, Fatima Zohra

    2015-01-01

    L’érysipèle sur cicatrice post opératoire est une entité rare, décrite principalement chez des patients présentant les facteurs de risque classiques de la maladie au niveau des sites de veinectomie pour pontage coronarien. En traumatologie orthopédie, nous n'avons que les 3 cas rapportés dans le travail de Dhrif survenus au décours d'une implantation prothétique chez des malades à risque. Nous présentons à travers cet article, le cas d'un érysipèle post opératoire sur une cicatrice d'ostéosynthèse d'une fracture fermée du pilon tibial, ayant la particularité du terrain et des circonstances de survenues, pour enfin conclure aux principes de la prévention primaire à adopter. PMID:26401204

  4. Los grandes telescopios ópticos e infrarrojos

    NASA Astrophysics Data System (ADS)

    Rodríguez-Espinosa, J. M.

    Recientemente se han puesto en funcionamiento telescopios de 8 y 10 metros de diámetro de su espejo primario que están significando un gran avance en las capacidades observacionales de la Astronomía moderna. Igualmente en nuestro país se está construyendo el Gran Telescopio de Canarias (GTC) que situará a la Astronomía española en la vanguardia de esta disciplina. En mi charla hablaré de las oportunidades observacionales que suponen estos grandes telescopios para la Astronomía moderna. Hablaré del GTC y del esfuerzo español por ser actores principales del desarrollo de la Astronomía moderna. Por último, mostraré brevemente los proyectos futuros de grandes telescopios que se están proponiendo a ambos lados del Atlántico.

  5. Barreras y Facilitadores en el Reclutamiento y la Retención de Parejas Heterosexuales en Intervenciones Preventivas en VIH/SIDA

    PubMed Central

    Hernández-Hernández, Alberto L.; Perez-Jimenez, David

    2012-01-01

    Compendio El Reclutamiento y la Retención (R&R) de participantes es fundamental para el éxito de estudios y para el desarrollo de intervenciones preventivas. El R&R de participantes determina la validez y efectividad de estos programas. En este trabajo examinamos algunos de los factores que facilitan y dificultan el R&R en los proyectos preventivos y ofrecemos algunas alternativas para mejorar los índices de R&R. Realizamos dos estudios, en el primero administramos el Instrumento de Informatión, Motivatión y Conductas-Español (IIMC-E) a un grupo de 26 parejas heterosexuales (52 participantes). En el segundo, entrevistamos a 5 parejas VIH discordantes (10 participantes). Encontramos que el 75% de los/las participantes indicó que su trabajo era una de las principales barreras que dificultan la asistencia a las actividades. Otras barreras son las responsabilidades laborales y familiares. Encontramos que la principal barrera fue el miedo a la revelación del estado serlógico. Los principales facilitadores del R&R son la coordinación adecuada y el seguimiento telefónico ofrecido por parte del personal del proyecto. Concluimos que en el desarrollo e implantación de programas de prevención el investigador/a debe tomar en cuenta la adaptación de aspectos logísticos como la disponibilidad y las necesidades particulares de los/las participantes. PMID:23264700

  6. [Barriers and Facilitators in the Recruitment and Retention of Heterosexual Couples for Preventive Interventions.

    PubMed

    Hernández-Hernández, Alberto L; Perez-Jimenez, David

    2010-01-01

    El Reclutamiento y la Retención (R&R) de participantes es fundamental para el éxito de estudios y para el desarrollo de intervenciones preventivas. El R&R de participantes determina la validez y efectividad de estos programas. En este trabajo examinamos algunos de los factores que facilitan y dificultan el R&R en los proyectos preventivos y ofrecemos algunas alternativas para mejorar los índices de R&R. Realizamos dos estudios, en el primero administramos el Instrumento de Informatión, Motivatión y Conductas-Español (IIMC-E) a un grupo de 26 parejas heterosexuales (52 participantes). En el segundo, entrevistamos a 5 parejas VIH discordantes (10 participantes). Encontramos que el 75% de los/las participantes indicó que su trabajo era una de las principales barreras que dificultan la asistencia a las actividades. Otras barreras son las responsabilidades laborales y familiares. Encontramos que la principal barrera fue el miedo a la revelación del estado serlógico. Los principales facilitadores del R&R son la coordinación adecuada y el seguimiento telefónico ofrecido por parte del personal del proyecto. Concluimos que en el desarrollo e implantación de programas de prevención el investigador/a debe tomar en cuenta la adaptación de aspectos logísticos como la disponibilidad y las necesidades particulares de los/las participantes. PMID:23264700

  7. Análisis del futuro marco de referencia internacional

    NASA Astrophysics Data System (ADS)

    Cionco, G. R.; Arias, E. F.

    La técnica de interferometría de muy larga línea de base (VLBI) se aplica hoy a la astrometría para el cálculo de posiciones precisas de radiofuentes extragalácticas. Por tratarse de objetos lejanos, sus movimientos propios aparentes pueden considerarse nulos; esta propiedad hace que los catálogos de radiofuentes extragalácticas VLBI constituyan la mejor materialización de un sistema de referencia celeste inercial definido cinemáticamente. La Unión Astronómica Internacional (IAU) recomendó la adopción de un nuevo sistema de referencia celeste internacional materializado por las coordenadas ecuatoriales de objetos extragalácticos observados con le técnica VLBI. Para superar la precisión astrométrica actual es necesaria una mejora en la modelización de aquellos fenómenos que pueden introducir desviaciones sistemáticas en el marco de referencia celeste. El objetivo de este trabajo es poner de manifiesto las sistematicidades presentes en los distintos marcos de referencia elaborados con el próposito de materializar el nuevo sistema de referencia celeste de la IAU. Para la comparación de los distintos marcos de referencia se propone un modelo de tres rotaciones diferenciales más un término lineal que procura absorber los efectos sistemáticos presentes en las coordenadas. Se analiza igualmente la estabilidad de la solución cuando se utilizan distintos conjuntos de objetos de definición.

  8. Teorí­as de primer y segundo orden sobre el potencial de ciertas figuras de equilibrio de cuerpos celestes

    NASA Astrophysics Data System (ADS)

    Gumbau, Manuel Forner

    2010-11-01

    Uno de los problemas que aborda la Mecánica Celeste es la determinación de las figuras de equilibrio de los cuerpos celestes. Para investigar su solución mediante métodos directos, se precisa evaluar el potencial generado por su autogravitación, el generado por su fuerza centrí­fuga y el generado por la fuerza de atracción entre los cuerpos. Los métodos clásicos de Finlay y Kopal que afrontan estos problemas, para determinar el potencial autogravitatorio en las configuraciones de equilibrio, emplean desarrollos en serie de los potenciales interior y exterior del potencial autogravitatorio. Estos métodos incurren en el error de suponer la convergencia en capas donde resulta cuestionable dicha convergencia para estos desarrollos en serie. En este trabajo se han elaborado unos algoritmos que contemplan toda la casuí&stica y que permiten una manipulación efic iente del producto de polinomios de Legendre, del producto de funciones asociada s de Legendre y del producto de armónicos esféricos como combinacióon lineal de ellos mismos, respectivamente. Se han obtenido, para primer y segundo orden en las amplitudes, los desarrollos correctos para los potencial es interior y exterior del potencial autogravitatorio para configuraciones de equilibrio aisladas, y , en primer orden de amplitudes, los mismos potenciales para los sistemas binarios próximos. Se ha elaborado un método analítico, en primer orden respecto de las amplitudes, para la determinación del potencial de marea en sistemas binarios próximos en el cual se manifiesta la forma de la componente secundaria del sistema

  9. Comportamiento dinámico de asteroides en la región 23 < a < 26 UA

    NASA Astrophysics Data System (ADS)

    López García, F.

    Los Kuiper Belt Objects (KBOs) pueden ser una fuente de origen de los cometas de corto período. Muchos de los KBOs observados parecen provenir, al igual que el sistema Pluton-Charonte, de órbitas resonantes con Neptuno. Los Centauros son objetos que dinámicamente provienen de órbitas inestables cuyo semieje mayor se encuentra entre las órbitas de Júpiter y Neptuno. Pudiera ser que estos cuerpos fueron expulsados desde la región del cinturón de Kuiper y se encuentran en un proceso de ``scattering" debido a los efectos gravitacionales de los planetas gigantes. Su tiempo de vida dinámico es de algunos millones de años. La evolución orbital de los objetos trans-Neptunianos nos permite conocer su comportamiento anterior, por eso, es importante su relación dinámica con la evolución orbital de Neptuno. El objeto de este trabajo es estudiar el comportamiento dinámico de partículas test que se encuentran entre las resonancias 3:2 con Neptuno y 2:3 con Urano, las cuales comprenden una región de 2 UA aproximadamente. Los primeros resultados indican que la mayoría de los objetos ficticios son eyectados hacia la parte externa del Sistema Solar, mientras que sólo una parte pequeña del total de objetos estudiados, aproximadamente un 7%, son eyectados hacia la parte interna del Sistema Solar, y en algunos casos sus órbitas pueden cruzar la órbita de los planetas terrestres.

  10. Integrated system to automatize information collecting for the primary health care at home.

    PubMed

    Oliveira, Edson N; Cainelli, Jean; Pinto, Maria Eugênia B; Cazella, Silvio C; Dahmer, Alessandra

    2013-01-01

    Data collected in a consistent manner is the basis for any decision making. This article presents a system that automates data collection by community-based health workers during their visits to the residences of users of the Brazilian Health Care System (Sistema Único de Saúde - SUS) The automated process will reduce the possibility of mistakes in the transcription of visit information and make information readily available to the Ministry of Health. Furthermore, the analysis of the information provided via this system can be useful in the implementation of health campaigns and in the control of outbreaks of epidemiological diseases. PMID:23920593

  11. Observaciones del CH interestelar y el continuo en 3,3 GHz

    NASA Astrophysics Data System (ADS)

    Olano, C. A.; Combi, J. A.; Pöppel, W.; Benaglia, P.; Sanz, A. J.; Bava, J. A.

    Se informa sobre el proyecto que se lleva a cabo en el IAR con el propósito de observar las líneas hiperfinas del estado fundamental del CH y el continuo en la banda de 3,3 GHz. El nuevo receptor construído en nuestro laboratorio para tal fin se instaló sobre uno de los radiotelescopios, funcionando conjuntamente con los sistemas de procesamiento actuales del IAR. Los resultados de las primeras observaciones, realizadas tanto en las líneas espectrales como en el continuo sobre fuentes conocidas, fueron satisfactorios.

  12. Organization of an information system for food and nutrition programmes in Costa Rica.

    PubMed

    Valverde, V; Rojas, Z; Vinocur, P; Payne, P; Thomson, A

    1981-01-01

    This paper discusses the information needed for multidisciplinary planning aimed at reducing nutritional deprivation in Costa Rica. In recent years, an approach has been developed for organizing data and information so as to define and described target groups of households. The development of a functional classification, a central activity of the Sistema de Información en Nutrición (SIN), is described and a preliminary description of the population groups affected by malnutrition presented. The major objectives of SIN are outlined and the possibilities of applying the same system to other countries discussed. PMID:7327298

  13. From 9 to 12 and Finally 8: how Many Planets are around the Sun? (Spanish Title: De 9 a 12 y Finalmente 8: ¿Cuántos Planetas Hay Alrededor del Sol?) De 9 a 12 e Finalmente 8: Quantos Planetas Existem AO Redor do Sol?

    NASA Astrophysics Data System (ADS)

    Tancredi, Gonzalo

    2007-12-01

    The International Astronomical Union, the organization that groups together the professional astronomers over the world, has recently adopted a historical definition: What is a planet in the Solar System? Changing 76 years of tradition, our Solar System has now 8 planets and an increasing number of a new category of bodies named "dwarf planets", among them is the former planet Pluto. In this article we present the reasons that support the resolution and we describe the participation of the Latin-American astronomers in the process to adopt it. La Unión Astronómica Internacional, la organización que agrupa a los astrónomos profesionales del planeta, acaba de adoptar una definición histórica: ¿Qué es un planeta en nuestro Sistema Solar? Cambiando 76 años de tradición, según esta definición, nuestro Sistema Solar cuenta con 8 planetas y una creciente cantidad de "planetas enanos", entre los que quedó incluido el hasta hace poco planeta Plutón. En el presente artículo se presentarán los argumentos que fundamentan esta resolución y la participación que han tenido los astrónomos latinoamericanos en la adopción de la misma. A União Astronômica Internacional, a organização que agrupa os astrônomos profissionais do planeta, acaba de adotar uma definição histórica: O que é um planeta em nosso Sistema Solar? Mudando 76 anos de tradição, segundo esta definição, nosso Sistema Solar conta com 8 planetas e uma crescente quantidade de "planetas anões", entre os quais foi incluido o até há pouco planeta Plutão. No presente artigo serão apresentados os argumentos que fundamentam esta resolução e a participação que tiveram os astrônomos latino-americanos na adoção da mesma.

  14. Fotoexcitación de Moléculas Pequeñas

    NASA Astrophysics Data System (ADS)

    González Díaz, P. F.

    El modelo estocástico no puede justificar la excitación multi-fotónica de moléculas pequeñas o muy simétricas. Basándonos en un escenario de interacción radiación-molécula cooperativo para la absorción de N-1 fotones IR por un sistema de N niveles, se especula que un posible mecanismo para la excitación no estocástica de moléculas pudiera ser la generación de procesos caóticos intra-moleculares.

  15. Intermitência alfvênica gerada por caos na atmosfera solar e no vento solar

    NASA Astrophysics Data System (ADS)

    Rempel, E. L.; Chian, A. C.-L.; Macau, E. E. N.; Rosa, R. R.

    2003-08-01

    Dados medidos no vento solar rápido proveniente dos buracos coronais revelam que os plasmas no meio interplanetário são dominados por flutuações Alfvênicas, caracterizadas por uma alta correlação entre as variações do campo magnético e da velocidade do plasma. As flutuações exibem muitas características esperadas em turbulência magneto-hidrodinâmica totalmente desenvolvida, tais como intermitência e espectros contínuos. Contudo, os mecanismos responsáveis pela evolução de turbulência Alfvênica intermitente não são completamente compreendidos. Neste trabalho a teoria de caos é usada para explicar como sistemas Alfvênicos, modelados pela equação Schrödinger não-linear derivativa e pela equação Kuramoto-Sivashinsky, podem se tornar fortemente caóticos à medida em que parâmetros do plasma são variados. Pequenas perturbações no parâmetro de dissipação podem fazer com que o sistema mude bruscamente de um regime periódico, ou fracamente caótico, para um regime fortemente caótico. As séries temporais das flutuações do campo magnético nos regimes fortemente caóticos exibem comportamento intermitente, em que fases laminares ou fracamente caóticas são interrompidas por fortes estouros caóticos. É mostrado que o regime fortemente caótico é atingido quando as soluções periódicas ou fracamente caóticas globalmente estáveis interagem com soluções do sistema que são fortemente caóticas, mas globalmente instáveis. Estas soluções globalmente instáveis são conjuntos caóticos não-atrativos conhecidos como selas caóticas, e são responsáveis pelos fortes estouros nos regimes intermitentes. Selas caóticas têm sido detectadas experimentalmente em uma grande variedade de sistemas, sendo provável que elas desempenhem um papel importante na turbulência intermitente observada em plasmas espaciais.

  16. Apoyo a Estudios Geodinamicos con GPS en Guatemala

    NASA Astrophysics Data System (ADS)

    Robles, V. R.

    2013-05-01

    El Instituto Geografico Nacional de Guatemala implemento 17 estaciones GNSS en el año 2009, como un proyecto de credito mixto de donacion de equipamiento del Gobierno de Suiza, el cual, este equipamiento de estaciones CORS GNSS es un sistema de recepción y transmisión de datos crudos GPS RInex que utiliza la tecnologia Spider Web de Leica, asi mismo este sistema esta sirviendo para el espablecimiento de un marco geodesico nacional de coordenadas geodesicas oficiales, el cual se calculan u obtienen las velocidades en tiempos temporales programados de las 17 Estaciones CORS. La infraestructura del marco geodesico de Guatemala esta sirviendo de base para las aplicaciones de estudios geodinamicos como el monitoreo de del desplazamiento de las placas tectonicas por medio de un estudio que se inicio en el año de 1999, llamado medicion con GPS el sistema de Fallas de los rios Polochic Motagua de Guatemala, tambien para un estudio que se implemento para deformación de corteza terrestre local en un Volcan Activo de Guatemala llamado Pacaya. Para el estudio de medicion con GPS en el sistema de falla de los Rios del polochic Motagua se implementaron 16 puntos para medir con GPS de dos frecuencias en el año de 1999, el cual, tres puntos son estaciones geodesicas CORS IGS llamados GUAT, ELEN y HUEH, despues en el año de 2003 se hizo otra medicion en un total de 20 puntos, que permitió calcular las velocidades de desplazamieinto de los puntos en mención, usando como referencia el modelo NUVEL 1A de DeMets de la placa de Norteamerica. Este estudio fue en cooperación internacional por la universidad de Nice de Francia y el IGNde Francia. Para el estudio del monitoreo con GPS del volcan activo de Guatemala, se implementaron cuatro puntos al rededor del volcan, el cual, se realizan cuatro mediciones al año, que permiten determinar axialmente la distancias entre los puntos, y rebisar estadisticamente cual es el comportamiento de las distancias en funcion del tiempo, si existen diferencias graduales crecientes o decrecientes, que nos da un indicativo del desplazamiento de la corteza terrestre al rededor del volcan.

  17. New information on regional subsidence and soil fracturing in Mexico City Valley

    NASA Astrophysics Data System (ADS)

    Auvinet, G.; Méndez-Sánchez, E.; Juárez-Camarena, M.

    2015-11-01

    In this paper, updated information about regional subsidence in Mexico City downtown area is presented. Data obtained by R. Gayol in 1891, are compared with information obtained recently from surveys using the reference points of Sistema de Aguas de la Ciudad de México (2008) and on the elevation of a cloud of points on the ground surface determined using Light Detection and Ranging (LiDAR) technology. In addition, this paper provides an overview of recent data obtained from systematic studies focused on understanding soil fracturing associated with regional land subsidence and mapping of areas susceptible to cracking in Mexico City Valley.

  18. On the Determination of Perturbations in Planetary Motions

    NASA Astrophysics Data System (ADS)

    Brunini, A.

    1990-11-01

    ABSTRACT. The main goal of this paper is to give an alternative way when the physical reaiity is too difficult to interpret, in such form that small effects can be ignored in the force model of dynamical systems. RESUMEN. El principal objetivo de este trabajo es ofrecer una via alterna para cuando la realidad fisica es demasiado dificil de interpretar, en tal forma que los efectos pequefios puedan despreciarse en los modelos de fuerza de sistemas dinamicos. Key words: PLANETS AND SATELLITES-DYNAMICS

  19. Improving mating performance of mass-reared sterile Mediterranean fruit flies (Diptera: Tephritidae) through changes in adult holding conditions: demography and mating competitiveness

    SciTech Connect

    Liedo, P.; Salgado, S.; Oropeza, A.; Toledo, J.

    2007-03-15

    Mass rearing conditions affect the mating behavior of Mediterranean fruit flies (medflies) Ceratitis capitata (Wiedemann). We evaluated the effect of slight changes in the adult holding conditions of adult flies maintained for egg production on their mating performance. Colonization was initiated from wild flies collected as larvae from infested coffee berries (Coffea arabica L.). When pupae were close to adult emergence, they were randomly divided into 3 groups and the emerging adults were reared under the following conditions: (1) Metapa System (MS, control), consisting of 70 x 45 x 15 cm aluminum frame, mesh covered cages, with a density of 2,200 flies per cage and a 1:1 initial sex ratio; (2) Insert System (IS), with the same type of cage, and the same fly density and sex ratio as in the MS treatment, but containing twelve Plexiglas pieces (23 x 8.5 cm) to provide additional horizontal surface areas inside the cage; and (3) Sex-ratio System (SS), same as IS, but in this case the initial male: female ratio was 4:1. Three d later, newly emerged females were introduced, so the ratio became 3:1 and on the 6th d another group of newly emerged females was added to provide a 2:1 final sex ratio, at which the final density reached 1,675 flies per cage. The eggs collected from each of the 3 treatments were reared independently following standard procedures and the adults were held under the same experimental conditions. This process was repeated for over 10 to 13 generations (1 year). The experiment was repeated 3 times in 3 consecutive years, starting each replicate with a new collection of wild flies. Life tables were constructed for each treatment at the parental, 3rd, 6th, and 9th generations. Standard quality control parameters (pupation at 24 h, pupal weight, adult emergence, and flight ability), were estimated for each treatment every third generation in the third year. For the last generation each year, mating competitiveness was evaluated in field cage tests with wild flies. As colonization progressed, life expectancy and fecundity rates increased in the 3 rearing systems. There was no significant difference in standard quality control parameters among the 3 rearing systems. Wild males always achieved more matings than any of the mass reared males. Mating competitiveness of males from the IS, although surprisingly not from the SS, was significantly greater than that of males from the MS. Our results indicate that these slight changes in the adult holding conditions can significantly reduce the harmful effects of mass rearing on the mating performance of sterile flies. (author) [Spanish] Se ha demostrado que las condiciones de cria masiva afectan el comportamiento de apareamiento de la mosca del Mediterraneo Ceratitis capitata (Wiedemann). Nosotros evaluamos el efecto de ligeros cambios en las condiciones en las que los adultos son mantenidos para la produccion de huevos, en el desempeno de apareamiento de las moscas esteriles. La colonizacion se inicio con moscas silvestres colectadas como larvas en cerezas de cafe (Coffea arabica L.) infestadas. Cuando las pupas estuvieron cerca de la emergencia de los adultos, se dividieron en tres grupos al azar y los adultos recien emergidos fueron criados en las siguientes condiciones: (1) Sistema Metapa (MS, testigo), consistente en jaulas con marco de aluminio de 70 x 45 x 15 cm, cubiertas con malla, con una densidad de 2,200 moscas por jaula y una relacion de sexos inicial de 1:1; (2); Sistema Insertos (IS), con el mismo tipo de jaula, densidad de moscas, y relacion de sexos que en el MS, pero conteniendo 12 piezas de plexiglas (23 x 8.5 cm) para proporcionar superficie horizontal al interior de la jaula; y (3) Sistema de Relacion de Sexos (SS), igual que el IS, pero en este caso la relacion inicial macho: hembra fue de 4:1, tres dias despues se introdujeron hembras recien emergidas para tener una relacion de 3:1 y en el 6 dia se anadio otro grupo de hembras para tener una relacion final de sexos de 2:1, que equivale a una densidad final de 1,675 moscas por jaula. Los huevos colectados de cada tratamiento fueron criados independientemente siguiendo los procedimientos estandares y los adultos fueron mantenidos en las mismas condiciones experimentales. Esto se repitio por 10 a 13 generaciones (un ano). El experimento se repitio en tres ocasiones en anos consecutivos, iniciando cada repeticion con una nueva colecta de moscas silvestres. Se construyeron tablas de vida de cada tratamiento en las generaciones parental, 3 a, 6 a y 9 a . Se estimaron los parametros estandares de calidad (pupacion a las 24 h, peso de pupa, emergencia de adultos y habilidad de vuelo) para cada tratamiento, cada tercera generacion en el tercer ano. En la ultima generacion de cada ano, se evaluo la competitividad sexual en pruebas en jaulas de campo con moscas silvestres. Conforme avanzo la colonizacion, se encontro que la esperanza de vida y las tasas de fecundidad se incrementaron en los tres sistemas de cria. No hubo diferencia significativa en los parametros estandar de control de calidad entre los tres sistemas. Los machos silvestres siempre lograron mas apareamientos que los machos procedentes de cada sistema de cria masiva. La competitividad de los machos del sistema IS fue significativamente mayor que la de los machos del sistema MS. Nuestros resultados indican que estas ligeras modificaciones en las condiciones de la colonia de adultos reducen los efectos adversos de la cria masiva sobre el desempeno de apareamiento de los machos esteriles. (author)

  20. The first Italian Superconducting Fault Current Limiter: Results of the field testing experience after one year operation

    NASA Astrophysics Data System (ADS)

    Martini, L.; Bocchi, M.; Ascade, M.; Valzasina, A.; Rossi, V.; Ravetta, C.; Angeli, G.

    2014-05-01

    Ricerca sul Sistema Energetico S.p.A. (RSE) has been gaining a relevant experience in the simulation, design and installation of resistive-type Superconducting Fault Current Limiter (SFCL) devices for more than five years in the framework of a R&D national project funded by the Ricerca di Sistema (RdS). The most recent outcome of this research activity is the installation of a resistive-type BSCCO-based 9 kV / 3.4 MVA SFCL device in a single feeder branch of the Medium Voltage (MV) distribution network managed by A2A Reti Elettriche S.p.A (A2A) in the Milano area. This installation represents the first SFCL successfully installed in Italy. In this paper, we report on the main outcomes after a more than 1-year long steady-state field testing activity. The design of an upgraded device to be installed in the same substation has already been initiated: the new SFCL will allow to protect four different feeders, therefore implying a device upgrade up to 15.6 MVA.

  1. Análisis fotométrico-espectroscópico de un par de binarias en NGC 3532

    NASA Astrophysics Data System (ADS)

    Gramajo, L.; González, J. F.

    Presentamos el informe de avance de un proyecto que apunta a la determinación de masas y radios de precisión en estrellas tempranas de cúmulos abiertos mediante el análisis fotométrico-espectroscópico de sistemas binarios detached con baja rotación. Con ello se pretende determinar el estado evolutivo de estas estrellas y confrontar su estructura con modelos estelares teóricos con distinto grado de ``overshooting". Los primeros objetos seleccionados son dos sistemas binarios de espectros dobles (BDA27 y BDA363) detectados en el cúmulo NGC 3532. Presentamos la órbita espectroscópica obtenida para la binaria eclipsante BDA27, para la cual obtuvimos un período de 4.29 días y una razón de masas q=0.62. Derivamos sus parámetros absolutos preliminares usando nuestra curva de velocidad y datos fotométricos existentes en la literatura, y presentamos estimas del alcance de nuestros resultados una vez que hayamos completado nuestras observaciones con nuevas curvas de luz.

  2. Un asteroide proveniente de la Luna

    NASA Astrophysics Data System (ADS)

    Tancredi, G.

    El descubrimiento de un débil objeto en movimiento por el telescopio Spacewatch (un instrumento dedicado a la búsqueda de Asteroides Cercanos a la Tierra) en 1991, ha generado una gran controversia en la comunidad planetaria. El objeto, denominado 1991 VG, tiene elementos orbitales llamativamente similares a los de la Tierra, lo que ha llevado a B. G. Marsden a aventurar:``El objeto podría ser una nave espacial en retorno (IAUC 5387)". Luego de analizar las características dinámicas de 1991 VG y las diferentes hipótesis sobre su origen, favorecemos la alternativa de que el objeto es un gran fragmento de material eyectado de la Luna durante un reciente impacto (en las últimas decenas de miles de años). El hallazgo en 1983 en la Antártida de meteoritos con composición tipo lunar, confirma la posibilidad de que material de la superficie del satélite puede ser eyectado a velocidades superiores a la de escape del sistema Tierra-Luna y alcance órbitas heliocéntricas. Los elementos orbitales de 1991 VG corresponden a los valores alcanzados por partículas que apenas escapan de la gravedad lunar y entran en órbitas heliocéntricas a través del punto Lagrangiano exterior del sistema Tierra-Sol.

  3. Difusión de Arnold en un modelo simple

    NASA Astrophysics Data System (ADS)

    Cincotta, P. M.; Nuñez, J. A.; Miloni, O.

    Investigadores como Merritt, Valluri, Pfenniger o Contopoulos (por citar los más relevantes) consideran seriamente la hipótesis que la difusión de Arnold juega un rol importante en la evolución dinámica de los sistemas estelares y planetarios. Sin embargo no existe ninguna evidencia. El mayor problema para investigar fenómenos como éste es que uno debe estudiar numéricamente sistemas multidimensionales (más de dos grados de libertad) y visualizar de alguna manera el espacio de fases (más de cuatro dimensiones). Más complicado aún es el caso de difusión de Arnold, donde deben considerarse tiempos de movimiento extremadamente largos y tratar con parámetros exponencialmente pequeños. El propósito de este trabajo es estudiar, en un modelo simple 3D, la existencia o no de difusión de Arnold mediante experimentos numéricos y estimaciones analíticas. Siguiendo los trabajos de Cincotta (2000) y Cincotta, Nuñez y Simo (2000), aquí se pretende ``visualizar" la difusión y, a la vez, determinar la escala de tiempo en la que ésta se podría manifestar. Este trabajo es el escalón inicial para luego abordar este problema en modelos.

  4. Final report on COOMET.AUV.A-S1: Technical report on supplementary comparison 'Comparison of national standards of the sound pressure unit in air through calibration of working reference microphones'

    NASA Astrophysics Data System (ADS)

    Pozdeeva, Valentina; Chalyy, Vladimir

    2014-01-01

    The supplementary comparison COOMET.AUV.A-S1 for secondary calibration methods using WS1 and WS2 measurement microphones was carried out from 2009 to 2010. The results were submitted to and approved by CCAUV in April 2014. Four National Metrology Institutes took part in this comparison and are as follows: BelGIM (Belarus), VNIIFTRI (Russia), SMU (Slovakia) and DP NDI 'Sistema' (Ukraine). Three of the above NMIs (VNIIFTRI, SMU and DP NDI 'Sistema') had earlier participated in COOMET key comparisons and one NMI (VNIIFTRI) had also participated in CCAUV key comparisons. The Comparison Reference Values were calculated as the weighted mean values from results obtained by three institutes. The comparison results show agreement for all participants in the frequency range from 20 Hz to 12.5 kHz for WS1 microphones, and in the frequency range from 20 Hz to 16 kHz for WS2 microphones. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  5. A comparative molecular analysis of water-filled limestone sinkholes in north-eastern Mexico.

    PubMed

    Sahl, Jason W; Gary, Marcus O; Harris, J Kirk; Spear, John R

    2011-01-01

    Sistema Zacatón in north-eastern Mexico is host to several deep, water-filled, anoxic, karstic sinkholes (cenotes). These cenotes were explored, mapped, and geochemically and microbiologically sampled by the autonomous underwater vehicle deep phreatic thermal explorer (DEPTHX). The community structure of the filterable fraction of the water column and extensive microbial mats that coat the cenote walls was investigated by comparative analysis of small-subunit (SSU) 16S rRNA gene sequences. Full-length Sanger gene sequence analysis revealed novel microbial diversity that included three putative bacterial candidate phyla and three additional groups that showed high intra-clade distance with poorly characterized bacterial candidate phyla. Limited functional gene sequence analysis in these anoxic environments identified genes associated with methanogenesis, sulfate reduction and anaerobic ammonium oxidation. A directed, barcoded amplicon, multiplex pyrosequencing approach was employed to compare ∼100,000 bacterial SSU gene sequences from water column and wall microbial mat samples from five cenotes in Sistema Zacatón. A new, high-resolution sequence distribution profile (SDP) method identified changes in specific phylogenetic types (phylotypes) in microbial mats at varied depths; Mantel tests showed a correlation of the genetic distances between mat communities in two cenotes and the geographic location of each cenote. Community structure profiles from the water column of three neighbouring cenotes showed distinct variation; statistically significant differences in the concentration of geochemical constituents suggest that the variation observed in microbial communities between neighbouring cenotes are due to geochemical variation. PMID:20738374

  6. Estudio teórico de moléculas de interés en Astrofísica: compuestos binarios policarbonados

    NASA Astrophysics Data System (ADS)

    Largo-Cabrerizo, A.

    Se han detectado en el espacio distintos compuestos binarios policarbonados (que se pueden formular como CnX), algunos de ellos con elementos de la primera fila del sistema periódico, pero también existen otros que contienen elementos de la segunda fila, como azufre o silicio. La información experimental sobre estos últimos compuestos es escasa, por lo que los estudios teóricos son especialmente valiosos en este campo. En esta comunicación presentaremos los avances mas recientes que sobre el tema ha realizado nuestro grupo. Incidiremos particularmente en dos aspectos. En primer lugar resumiremos los estudios en los que hemos intentado proporcionar información estructural sobre carburos metálicos formados por sodio, magnesio, aluminio o calcio, que pueda ser de ayuda a la hora de caracterizar estas moléculas en laboratorio como paso previo a su eventual detección en el espacio. Un aspecto importante dentro de este primer apartado es el análisis de las propiedades moleculares en función del tamaño del sistema (cuantificado en el numero de átomos de carbono) con el objeto de intentar sistematizar su estudio. En segundo lugar comentaremos brevemente algunos de los estudios realizados sobre posibles reacciones que pueden ser vías de síntesis de este tipo de compuestos en el medio interestelar.

  7. Base de linhas moleculares para síntese espectral estelar

    NASA Astrophysics Data System (ADS)

    Milone, A.; Sanzovo, G.

    2003-08-01

    A análise das abundâncias quí micas fotosféricas em estrelas do tipo solar ou tardia, através do cálculo teórico de seus espectros, emprega a espectroscopia de alta resolução e necessita de uma base representativa de linhas atômicas e moleculares com suas respectivas constantes bem determinadas. Nesse trabalho, utilizamos como ponto de partida as extensas listas de linhas espectrais de sistemas eletrônicos de algumas moléculas diatômicas compiladas por Kurucz para a construção de uma base de linhas moleculares para a sí ntese espectral estelar. Revisamos as determinações dos fatores rotacionais de Honl-London das forças de oscilador das linhas moleculares, para cada banda vibracional de alguns sistemas eletrônicos, seguindo a regra usual de normalização. Usamos as forças de oscilador eletrônicas da literatura. Os fatores vibracionais de Franck-Condon de cada banda foram especialmente recalculados empregando-se novas constantes moleculares. Reproduzimos, com êxito, as absorções espectrais de determinadas bandas eletrônicas-vibracionais das espécies moleculares C12C12, C12N14 e Mg24H em espectros de estrelas de referência como o Sol e Arcturus.

  8. Amplificadores en bandas para receptores de uso radioastronómicos

    NASA Astrophysics Data System (ADS)

    Bava, A. J.; Sanz, A. J.

    Está en curso de realización en el IAR un cabezal de receptor, en la frecuencia de 3.3 GHz. Este receptor, conjuntamente con los sistemas de procesamientos actuales del IAR y con los futuros proyectos de procesamientos, permitirán las observaciones de las líneas de la molécula de CH, de gran interés astrofísico, y las observaciones en el continuo que complementarán las realizadas en 1420 MHz. En este trabajo, se presentan el diseño de los amplificadores de bajo ruido, que van a conformar las primeras etapas del receptor de 3.3 GHz. El desarrollo de los mismos se realizó teniendo en cuenta que la temperatura del sistema, según consideraciones observacionales, deberá ser de 60oK. Por tal motivo se realizó un diseño de bajo ruido utilizando como elemento activo un HEMT. Tanto los métodos de diseño, como el circuito final, fueron realizados y comprobados con programas de simulación, permitiendo de esta forma obtener el amplificador deseado.

  9. Capture of Anastrepha species (Diptera: Tephritidae) with multilure traps and biolure attractants in Guatemala

    SciTech Connect

    Martinez, A.J.; Salinas, E.J.; Rendon, P.

    2007-03-15

    Two trapping systems were compared in a study in Guatemala during the wet season, May through Dec 2001. Trap/lure combinations consisting of green or yellow-based plastic McPhail-like traps baited with a synthetic 2-component lure (putrescine and ammonium acetate) and 300 mL of propylene glycol antifreeze as a preservative were compared to the traditional glass McPhail baited with torula yeast/borax and 300 mL of water. Both systems captured several key Anastrepha species including Anastrepha ludens Loew, A. obliqua, Macquart, A. serpentina Weidemann, A. striata Schiner, A. distincta Greene, A. fraterculus Weidemann as well as Ceratitis capitata Weidemann. Additionally, 13 other Anastrepha spp. were captured with the synthetic lure. The plastic traps captured more key flies than the McPhail trap except for A. distincta where there were no significant differences between the yellow-based plastic trap and the McPhail trap and no significant differences between any trap and lure for trapping A. fraterculus. The synthetic lure lasted 10 weeks. The sex ratio was female-biased for almost all captured key species in both systems. Moreover, there were significant numbers of captured nontarget insects in all traps; however, the captured flies in those traps with the synthetic lure were not adversely affected by these insects. Propylene glycol-based antifreeze was a superior preservative when compared to borax/water. (author) [Spanish] En Guatemala, se compararon dos sistemas de trampeo durante la epoca lluviosa de Mayo a Deciembre, 2001. Combinaciones de trampa/atrayente que consistieron de trampas de plastico con bases verdes o amarillos y con atrayentes sinteticos (acetate de amoniaco y putrecina) fueron comparadas con el sistema de trampeo tradicional McPhail de vidrio cebada con torula y borax en agua. Los dos sistemas capturaron moscas del genero Anastrepha incluyendo Anastrepha ludens Loew, A. obliqua, Macquart, A. serpentina Weidemann, A. striata Schiner, A. distincta Greene, A. fraterculus Weidemann y Ceratitis capitata Weidemann. Ademas, se capturaron 13 especias adicionales de Anastrepha asi como Toxotrypana curvicauda Gerstaecker con el cebo sintetico. El cebo sintetico fue efectivo por diez semanas sin recebar. Las trampas de plastico capturaron mas moscas del genero Anastrepha que la trampa de cristal McPhail. Las excepciones fueron A. distincta en donde no hubo differencias el la captura con la trampa de plastico con base amarillo y la trampa McPhail de cristal asi como A. fraterculus en donde no hubo differencias comparando la captura de moscas con ambos sistemas. La proporcion sexual de las moscas capturadas con los dos sistemas fue al favor de las hembras. La captura de otros tipos de insectos fue significantemente elevado, sin embargo, las moscas capturadas con los cebos sinteticos no fueron afectados adversamente por estos insectos. El 10% del anticongelante, glicol propilico, fue superior al borax/agua como conservador de las moscas capturardas. (author)

  10. Condições físicas do disco de acréscimo da nova-anã V4140 SGR

    NASA Astrophysics Data System (ADS)

    Borges, B.; Baptista, R.

    2003-08-01

    Discos de acréscimo são aparatos cósmicos que permitem que matéria seja eficientemente acrescida sobre uma fonte compacta pela remoção de momento angular via tensões viscosas enquanto transforma a energia potencial gravitacional em calor e, posteriormente, em radiação. Sistemas binários semi-ligados, como Variáveis Cataclísmicas (VCs) não-magnéticas, são talvez os melhores ambientes encontrados para o estudo da física desses discos de acréscimo. O desenvolvimento de técnicas de imageamento indireto, como o mapeamento por eclipses (MME) e a tomografia Doppler, permitiu avanços importantes na compreensão da física dos processos de acréscimo desses sistemas. V4140 Sagitarii é uma VC eclipsante de curto período orbital (~ 90 min) que não havia sido classificada como nova-anã ou polar. Neste trabalho apresentamos a análise do mapeamento por eclipse feito com dados de fotometria CCD nas bandas B, V e R de V4140 Sgr realizada no LNA. O objeto foi observado no declínio de erupção em julho de 1992 e em erupção em julho de 2001, isso indicou a classificação do sistema como uma nova-anã. A análise, feita sobre os mapas já apresentados em trabalho anterior, apresenta (i) diagrama cor-cor, que indica uma emissão opticamente espessa nas partes internas do disco em quiescência (R < RL1); (ii) diagrama cor-magnitude, usado para inferir uma distância de 600 +/- 10 pc ao sistema; (iii) a distribuição radial de temperatura observada que concorda com a lei de disco espesso em estado estacionário TµR-3/4, com temperaturas em torno de 10000 K e 3000 K ns partes internas e externas do disco em quiescência, respectivamente; (iv) a evolução da distribuição de temperatura no declínio de erupção; (v) estimativa da transferência de massa de 109.9+/-0.1 M¤/ano em quiescência, similar àquelas observadas em novas-like. O sistema é comparado à outras novas-anãs (e.g. OY Car e Z Cha) em quiescência e erupção, mostrando-se tratar um objeto peculiar que difere em vários aspectos o comportamento esperado de novas-anãs.

  11. Gas-exchange patterns of Mediterranean fruit fly Pupae (Diptera: Tephritidae): A tool to forecast developmental stage

    SciTech Connect

    Nestel, D.; Nemny-Lavy, E.; Alchanatis, V.

    2007-03-15

    The pattern of gas-exchange (CO{sub 2} emission) was investigated for developing Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) pupae incubated at different temperatures. This study was undertaken to explore the usefulness of gas-exchange systems in the determination of physiological age in developing pupae that are mass produced for sterile insect technique projects. The rate of CO{sub 2} emission was measured in a closed flow-through system connected to commercial infrared gas analysis equipment. Metabolic activity (rate of CO{sub 2} emission) was related to pupal eye-color, which is the current technique used to determine physiological age. Eye-color was characterized digitally with 3 variables (Hue, Saturation and Intensity), and color separated by discriminant analysis. The rate of CO{sub 2} emission throughout pupal development followed a U-shape, with high levels of emission during pupariation, pupal transformation and final pharate adult stages. Temperature affected the development time of pupae, but not the basic CO{sub 2} emission patterns during development. In all temperatures, rates of CO{sub 2} emission 1 and 2 d before adult emergence were very similar. After mid larval-adult transition (e.g., phanerocephalic pupa), digital eye-color was significantly correlated with CO{sub 2} emission. Results support the suggestion that gas-exchange should be explored further as a system to determine pupal physiological age in mass production of fruit flies. (author) [Spanish] En el presente estudio se investigaron los patrones de intercambio gaseoso (emision de CO{sub 2}) en pupas de la mosca de las frutas del Mediterraneo (Ceratitis capitata Wiedemann) incubadas a diferentes temperaturas. El estudio fue realizado con la finalidad de explorar la utilizacion de sistemas de intercambio gaseoso en la determinacion de la edad fisiologica de pupas durante su produccion masiva en proyectos de mosca esteril. La proporcion de emision de CO{sub 2} fue medido en un sistema cerrado de 'flujo a traves del sistema' conectado a un detector infrarrojo de gases. La actividad metabolica de la pupa (emision de CO{sub 2}) fue contrastado al color del ojo de la pupa en desarrollo, que constituye la actual tecnica de determinacion de la edad fisiologica. El color de ojos en pupa fue determinado digitalmente, usando tres variables (Tendencia, Saturacion e Intensidad). Los colores fueron separados utilizando el analisis discriminatorio. Los patrones de emision de CO{sub 2} durante el desarrollo de la pupa sugieren una tendencia de U: una alta actividad metabolica durante la fase inicial de pupacion y transformacion y durante la fase final del adulto. La temperatura de incubacion afecto el tiempo de desarrollo pero no el patron basico de actividad metabolica. La proporcion de emision de CO{sub 2} uno y dos dias antes de la emergencia del adulto fue muy similar para pupas mantenidas en las diversas temperaturas. El color digital del ojo de la pupa se correlaciono significativamente con los patrones de emision de CO{sub 2} detectados a partir de la fase media de la transformacion de larva a adulto. Los resultados soportan la utilizacion de sistemas de intercambio gaseoso como un sistema auxiliar para la determinacion de la edad fisiologica en cria masiva de moscas de la fruta. (author)

  12. Caractéristiques bactériologiques des infections de liquide de dialyse péritonéale

    PubMed Central

    Jellouli, Manel; Ferjani, Meriem; Abidi, Kamel; Hammi, Yosra; Abdallah, Taieb Ben; Gargah, Tahar

    2015-01-01

    La péritonite infectieuse (PI) est la principale complication de la dialyse péritonéale (DP). L'objectif de notre travail était de déterminer l’écologie bactérienne des PI et d'adapter l'antibiothérapie selon les germes isolés et les résistances observées. Étude rétrospective effectuée chez tous les enfants traités par DP et ayant présenté une PI dans le service de pédiatrie de l'hôpital Charles Nicolle de Tunis (2004-2013). Au total, 61 ont développé 97 PI. L'incidence des PI était de 0,75 épisode/patient-année. La culture du LDP était négative dans 40 cas. Les Gram Positif ont été notés dans 56% des cas avec prédominance du Staphylococcus aureus. Les Gram négatif étaient retrouvés en seconde position (40%) représentés principalement par le Klebsiella pneumoniae et le Pseudomonas aeruginosa. Des souches de Staphylocoque méticilline résistant étaient isolées dans 21,4%. Les bactéries à Gram positif étaient résistantes aux céphalosporines de première génération dans 25% des cas et aucune résistance à la vancomycine n'avait été décelée. Les bactéries à Gram négatif avaient une résistance globale de 38% avec des souches β-lactamase à spectre élargi (BLSE). L'antibiothérapie empirique devra couvrir les germes à Gram positif par la vancomycine et les germes à Gram négatif par la ceftazidime. PMID:26893796

  13. Interpretation des donnees de flux de chaleur et de gravite dans le bouclier Canadien

    NASA Astrophysics Data System (ADS)

    Cheng, Li Zhen

    2000-10-01

    Le champ geothermique du Bouclier Canadien est caracterise par un flux moyen de 41 mW·m-2, qui suggere une production de chaleur moyenne dans la croute comprise entre 0.7 et 0.8 muW·m-3. Le flux de chaleur relativement faible favorise la stabilite du bouclier et lui a permis de resister a la deformation tectonique. Les variations du flux de chaleur a la surface sont dominees par la composition de la croute. Un flux eleve implique generalement une composition felsique et il est d'autant plus faible que la croute devient plus mafique. La production de chaleur en surface n'est pas representative de la production moyenne de la croute. Le flux de chaleur dans le Boucher Canadien ne depend donc pas de la production de chaleur en surface, mais depend de la composition principale de la croute. L'interpretation combinee des donnees geophysiques nous permet de determiner les variations de composition d'echelle crustale a partir desquelles il est possible d'etablir la structure de la croute. L'etude detaillee de l'Orogene de Trans-Hudson et de la Sous-province d'Abitibi a montre que le flux de chaleur, la gravite et la sismique lorsqu'elles sont combinees fournissent des contraintes efficaces pour determiner l'architecture crustale. En general, la croute est trop resistante pour se deformer par fluage, excepte tres localement. Le mode de deformation de la lithosphere continentale depend de la composition et du gradient geothermique. Nous montrons que la lithosphere du Bouclier Canadien demeure principalement fragile jusqu'a une profondeur de plus de 150 km. Une deformation ductile pourrait cependant etre possible localement a la base de la, croute, comme dans la ceinture de Thompson par exemple. Si l'on admet que la lithosphere peut resister a des contraintes allant jusqu'a 20 MPa (taux de deformation 3˙ < 10-15 s-1), l'epaisseur de la lithosphere est de l'ordre de 300 km pour la ceinture de Thompson et est superieure a 300 km pour la sous-province d'Abitibi. La resistance maximum de la lithosphere est atteinte dans la partie superieure du manteau. La lithosphere du Bouclier Canadien est donc capable de supporter d'importantes contraintes tectoniques sans deformation notable. C'est le regime fragile qui controle le comportement rheologique de la lithosphere superieure du bouclier.

  14. Les valvulopathies cardiaques en milieu hospitalier à Lomé (Togo)

    PubMed Central

    Balaka, Abago; Tchamdja, Toyi; Djibril, Mohaman Awalou; Djagadou, Kodjo Agbéko; Tchandana, Makilioubè; Damorou, Findibé; Agbétra, Aïssah

    2015-01-01

    Introduction Notre étude a consisté en l'identification les principales valvulopathies retrouvées en milieu hospitalier à Lomé (Togo). Méthodes Il s'agit d'une étude rétrospective, transversale, multicentrique menée du 1er janvier 2006 au 31 décembre 2010 et portant sur les dossiers de patients suivis dans le service de cardiologie du CHU Campus de Lomé. Résultats Du 1er janvier 2006 au 31 Décembre 2010,5412 patients ont été consulté dans le service de cardiologie du CHU Campus. Parmi eux, 241 (4,45%) présentaient une valvulopathie. On notait une prédominance féminine avec un sex-ratio H/F à 0,60. La moyenne d’âge était de 62,32 ans avec des extrêmes allant de 16 à 89 ans et un écart type de 14,27. Les antécédents le plus souvent retrouvés étaient l'hypertension artérielle (26,97%) et le diabète (8,29%). Parmi les motifs de consultations, les plus fréquents étaient la dyspnée (39,00%), les précordialgies (32,78%) et les palpitations (21,16%). A l'examen physique 30,70% des patients présentaient des signes de d'insuffisance cardiaque. A l’échographie, on notait des atteintes d'une seule valve (77,17%), de 02 valves (17,42%) ou 03 valves (5,4%). L'insuffisance mitrale (56,84%) et l'insuffisance aortique (30,70%) ont été les valvulopathies les plus fréquemment retrouvées. La maladie mitrale a été notée chez 05 patients. Les principales étiologies étaient dégénératives et ischémiques. Conclusion Les valvulopathies sont relativement fréquentes à Lomé. L'insuffisance cardiaque est leur principal mode de révélation. Les plus retrouvées sont l'insuffisance mitrale et aortique. PMID:26113911

  15. Mise à jour sur la prévention et le dépistage selon l’âge à l’intention des médecins de soins primaires canadiens

    PubMed Central

    Shimizu, Tawnya; Bouchard, Manon; Mavriplis, Cleo

    2016-01-01

    Résumé Objectif Faire la synthèse des meilleures lignes directrices fondées sur des données probantes concernant la prévention et le dépistage chez les adultes canadiens selon l’âge. Qualité des données Les recommandations du Groupe d’étude canadien sur les soins de santé préventifs représentent la source principale des renseignements et sont complétées par les recommandations pertinentes du Preventive Services Task Force des États-Unis lorsque celles du Groupe d’étude canadien étaient inaccessibles ou désuètes. Les guides de pratique des principales organisations nationales axées spécifiquement sur une maladie ou une spécialité ont aussi fait l’objet d’une révision pour prendre en compte les données factuelles les plus récentes. Message principal Les interventions de dépistage recommandées selon l’âge et le sexe sont présentées dans un tableau de synthèse où est mise en évidence la qualité des données à l’appui de ces recommandations. Un exemple de modèle à suivre dans les dossiers médicaux électroniques ou sur papier est aussi proposé. Conclusion Qu’il s’agisse d’une visite consacrée à la prévention ou d’une occasion saisie autrement de faire du counseling et du dépistage de prévention chez leurs patients, les médecins de soins primaires peuvent se servir de cette synthèse des recommandations fondées sur des données probantes pour maximiser leur efficience et prévenir d’importantes omissions ou des dépistages inutiles.

  16. Proprietes optiques et mecanismes de relaxation de l'energie des porteurs dans des boites quantiques

    NASA Astrophysics Data System (ADS)

    Perret, Nathalie Emmanuelle

    L'objet de ce doctorat est l'etude des proprietes optiques, et en particulier de la relaxation de l'energie des porteurs dans des structures a boites quantiques d'InAs/GaAs. Le travail experimental a ete realise grace aux techniques de photoluminescence (PL) continue et de photoluminescence resolue dans le temps, sur des echantillons comprenant un tres grand nombre de boites. A l'aide des mesures experimentales effectuees sur une serie d'echantillons de boites quantiques interdiffusees a divers degres, et des calculs variationnels de leurs etats electroniques, nous avons demontre clairement que la largeur des raies d'emission de la PL, qui est due aux inhomogeneites dans l'ensemble de boites etudie, peut etre attribuee principalement a des fluctuations de la hauteur des boites. D'autre part, la determination des temps de montee et de decroissance des intensites de photoluminescence a montre l'importance de certains mecanismes de transport et de relaxation, en fonction des conditions experimentales. En effet, les temps caracteristiques de la capture, de la relaxation interniveaux et de la recombinaison des porteurs varient significativement, selon le mecanisme predominant, en fonction de la temperature, de la densite d'excitation et de la separation interniveaux quantiques. Ainsi, les principaux mecanismes mis en evidence sont: la localisation des porteurs dans les barrieres a basse temperature dans le cas des echantillons interdiffuses, les collisions de type Auger sous forte excitation, les processus multiphononiques et la re-emission thermique a haute temperature. Un modele de relaxation, base sur les equations d'evolution de la population de porteurs de chaque niveau quantique, a aussi ete developpe pour mieux identifier l'effet de chacun des principaux mecanismes de relaxation des porteurs considere separement. Ces simulations ont permis une analyse plus approfondie du role de ces mecanismes. Ainsi, nous avons mis en evidence l'importance de la localisation des porteurs dans la couche de mouillage, ainsi que l'importance des mecanismes de collisions Auger lors de la capture, la capture et la relaxation interniveaux des porteurs vers tous les niveaux d'energie inferieure simultanement. Finalement, les resultats experimentaux montrent que la relaxation de l'energie des porteurs est beaucoup plus rapide que cela avait ete predit initialement par la theorie du "phonon bottleneck". Nos resultats indiquent que l'intensite lumineuse emise par les boites est regie principalement par le taux de capture/relaxation interniveaux des porteurs dans les boites. Mais elle est limitee par la re-emission thermique des porteurs hors des boites, a haute temperature. (Abstract shortened by UMI.)

  17. Etude des connaissances, attitudes et pratiques en matière de réintégration sociale des femmes victimes de fistule obstétricale: région de l'Extrême-nord, Cameroun

    PubMed Central

    Martin, Sanou Sobze; Adogaye, Sali Ben Béchir; Rodrigue, Mabvouna Biguioh; Maurice, Douryang; Vivaldi, Teikeu Tessa Vladimir; Amede, Saah Fopa Michael; Marie, Ovaga Eyenga Landry; Meriam, Ausseil Sandra; Colizzi, Vittorio; Gianluca, Russo

    2015-01-01

    Introduction La fistule obstétricale est un orifice entre le vagin et la vessie ou le rectum, voire les deux. Ses impacts sont des conséquences anatomo-fonctionnelles et sociales. On estime à plus de 19 000 le nombre de femmes qui souffrent de fistule obstétricale au Cameroun. Méthodes Il s'agissait d'une étude transversale descriptive conduite dans trois districts de santé de la région de l'Extrême-nord. Vingt-huit femmes victimes de fistules obstétricales, quarante-deux membres de leur entourage et vingt-quatre agents de santé ont été interviewés entre Novembre et Décembre 2013. Trois types de questionnaires ont été utilisés. Les données ont été analysées dans Epi Info version 7.1.4.0. Les moyennes et les fréquences ont été calculées avec un intervalle de confiance à 95%. Résultats 46,4% des femmes victimes de fistule obstétricales interviewées avaient subi une intervention chirurgicale réparatrice parmi lesquelles, 61,5% bénéficiaient de la réintégration. Le fonds de commerce (62,5%) était l'aide la plus reçue. Vingt-deux membres de l'entourage savaient pourquoi on fait la réintégration. Selon eux, les considérations socioculturelles (68,2%), sont la principale barrière de la réintégration. D'après les agents de santé, le suivi psychosocial (58,3%) est la principale activité de la réintégration dans les centres de prise en charge de la fistule. Conclusion La prise en charge des fistules obstétricales au Cameroun souffre de manque de réintégration sociale. Ceci expliquerait en partie la persistance de cette pathologie. Un accent devrait être mis sur l'appui matériel, financier et sur le suivi psychosocial des femmes victimes de fistule obstétricale. PMID:26113915

  18. CONTAMINACIÓN AMBIENTAL, VARIABILIDAD CLIMÁTICA Y CAMBIO CLIMÁTICO: UNA REVISIÓN DEL IMPACTO EN LA SALUD DE LA POBLACIÓN PERUANA

    PubMed Central

    Gonzales, Gustavo F.; Zevallos, Alisson; Gonzales-Castañeda, Cynthia; Nuñez, Denisse; Gastañaga, Carmen; Cabezas, César; Naeher, Luke; Levy, Karen; Steenland, Kyle

    2015-01-01

    RESUMEN El presente artículo es una revisión sobre la contaminación del agua, el aire y el efecto del cambio climático en la salud de la población peruana. Uno de los principales contaminantes del aire es el material particulado menor de 2,5 μ (PM 2,5), en la ciudad de Lima, anualmente 2300 muertes prematuras son atribuibles a este contaminante. Otro problema es la contaminación del aire domiciliario por el uso de cocinas con combustible de biomasa, donde la exposición excesiva a PM 2,5 dentro de las casas es responsable de aproximadamente 3000 muertes prematuras anuales entre adultos, con otro número desconocido de muertes entre niños debido a infecciones respiratorias. La contaminación del agua tiene como principales causas los desagües vertidos directamente a los ríos, minerales (arsénico) de varias fuentes, y fallas de las plantas de tratamiento. En el Perú, el cambio climático puede impactar en la frecuencia y severidad del fenómeno de El Niño oscilación del sur (ENSO) que se ha asociado con un incremento en los casos de enfermedades como cólera, malaria y dengue. El cambio climático incrementa la temperatura y puede extender las áreas afectadas por enfermedades transmitidas por vectores, además de tener efecto en la disponibilidad del agua y en la contaminación del aire. En conclusión, el Perú, pasa por una transición de factores de riesgo ambientales, donde coexisten riesgos tradicionales y modernos, y persisten los problemas infecciosos y crónicos, algunos de los cuales se asocian con problemas de contaminación de agua y de aire. PMID:25418656

  19. Anomalies échocardiographiques chez l'hémodialysé chronique: prévalence et facteurs de risqué

    PubMed Central

    Ezziani, Mariam; Najdi, Adil; Mikou, Souad; Elhassani, Anis; Akrichi, Mohammed Amine; Hanin, Hakim; Arrayhani, Mohammed; Houssaini, Tarik Sqalli

    2014-01-01

    Introduction Les complications cardio-vasculaires sont la principale cause de mortalité et de morbidité chez les patients hémodialysés chroniques. Le but de cette étude est de décrire les différentes atteintes cardiaques à l’échocardiographie transthoracique et de dégager les facteurs associés aux principales atteintes. Méthodes Etude transversale monocentrique incluant des patients adultes hémodialysés depuis plus d'un an et ayant bénéficié d'une échocardiographie transthoracique durant l'année 2012. Notre étude descriptive puis analytique a porté sur l'analyse des données démographiques, cliniques, biologiques et échocardiographiques. Résultats 50 patients ont été colligés, 32 femmes et 18 hommes. Leur âge moyen est de 55 ± 14 ans avec une ancienneté moyenne en hémodialyse de 93 ± 55 mois. Les anomalies échocardiographiques retrouvées sont dominées par l'hypertrophie ventriculaire gauche chez 56% des patients et les valvulopathies chez 80%. Les calcifications valvulaires ont été notées dans 14% des cas, une dilatation du ventricule gauche dans 12%, une hypertension artérielle pulmonaire dans 10% et une péricardite dans 6% des cas. Une seule dysfonction du ventricule gauche a été notée et la fraction d’éjection systolique moyenne est de 68,9 ± 9,5%. L'analyse statistique de variance des différentes anomalies montre que l'hypertrophie ventriculaire gauche est positivement corrélée à l'hypertension artérielle (p = 0,046) et que les pressions artérielles moyennes systoliques (p = 0,005) et diastoliques (p = 0,035) sont significativement plus élevées chez les patients avec une hypertrophie du ventricule gauche. Conclusion Les anomalies échocardiographiques sont fréquentes chez les hémodialysés chroniques notamment l'hypertrophie ventriculaire gauche qui est fortement liée à la présence d'une hypertension artérielle. PMID:25419342

  20. La prévention de l’infection par le virus respiratoire syncytial

    PubMed Central

    Samson, L

    2009-01-01

    L’infection par le virus respiratoire syncytial (VRS) est la principale cause d’infection des voies respiratoires inférieures chez les jeunes enfants et pour cette raison, bon nombre des prématurés et des enfants présentant d’autres facteurs de risque doivent être hospitalisés chaque année au Canada. Le palivizumab, un anticorps monoclonal anti-VRS, peut réduire le taux d’hospitalisation et la gravité de la maladie d’un petit groupe de prématurés ou de nourrissons à haut risque pendant leur première saison de VRS. Le présent document de principes contient une analyse des publications ainsi que des recommandations à l’intention des médecins canadiens au sujet de son utilisation chez les prématurés et les autres nourrissons à risque.

  1. A Review of the McMorran Diet for Rearing Lepidoptera Species With Addition of a Further 39 Species

    PubMed Central

    Hervet, V. A. D.; Laird, R. A.; Floate, K. D.

    2016-01-01

    Research on cutworms led us to explore the use of the McMorran diet to rear lepidopteran species, mainly Noctuidae, under laboratory conditions. We documented the development of 103 lepidopteran species, including 39 species not previously reported in the literature, to be reared on this diet. Given its low cost, ease of preparation, and wide species’ acceptance, this diet provides a powerful tool for facilitating Lepidoptera and other insects rearing and research in the laboratory. Résumé Une recherche sur les noctuelles nous a permis d’élever des larves de nombreuses espèces de lépidoptères, principalement des noctuelles, sur un substrat artificiel du nom de «McMorran diet» en laboratoire. Nous reportons le développement de 103 espèces de lépidoptères, dont 39 espèces qui n’ont pas encore été documentées, comme pouvant se développer sur ce substrat artificiel. Étant donné son faible coût, facilité de préparation, et large champ d’action, ce substrat artificiel peut grandement faciliter la recherche sur les lépidoptères et autres insectes en laboratoire. PMID:26851296

  2. Salicylate de bismuth pour la diarrhée chez l’enfant

    PubMed Central

    Goldman, Ran D.

    2013-01-01

    Résumé Question J’ai reçu récemment un patient de 5 ans à qui, lors d’un voyage en Amérique du Sud, un médecin de famille local a prescrit du sous-salicylate de bismuth pour une diarrhée. Est-ce une pratique que nous devrions encourager? Réponse La recherche réalisée dans les pays en développement a fait valoir que l’utilisation du sous-salicylate de bismuth était efficace pour raccourcir la durée de la diarrhée. En dépit de ces constatations, son efficacité limitée, des préoccupations à propos du fait qu’il pourrait potentiellement causer le syndrome de Reye, les problèmes d’observance et son coût sont les principales raisons pour lesquelles on ne le recommande pas systématiquement pour les enfants.

  3. Utilisation D'un Modulateur de Phase Optique pour Realiser L'asservissement de la Frequence D'un Laser a Semi-Conducteurs

    NASA Astrophysics Data System (ADS)

    Levesque, Marc

    Cet ouvrage porte sur l'utilisation d'un modulateur de phase optique dans une boucle permettant d'asservir la frequence d'un laser a semi-conducteurs a une reference de frequence optique, en l'occurrence une vapeur atomique de rubidium 87. Nous y etudions principalement les mecanismes de generation du signal d'erreur. Un montage experimental est d'abord presente et la caracterisation complete du modulateur de phase est effectuee. Nous analysons ensuite les proprietes statiques du signal d'erreur dans le cas ou le signal applique au modulateur est periodique. Nous discutons de l'influence de parametres tels que la frequence et l'indice de modulation et la presence d'un effet Fabry -Perot accompagnant la modulation de phase. Enfin, nous montrons aussi qu'il est possible d'obtenir un signal d'erreur lorsque le signal de modulation est une sequence binaire aleatoire plutot qu'un signal periodique. Cela permet entre autres d'utiliser le meme modulateur de phase pour les fins de transmission et d'asservissement.

  4. Mitochondrial genomes reveal the extinct Hippidion as an outgroup to all living equids.

    PubMed

    Der Sarkissian, Clio; Vilstrup, Julia T; Schubert, Mikkel; Seguin-Orlando, Andaine; Eme, David; Weinstock, Jacobo; Alberdi, Maria Teresa; Martin, Fabiana; Lopez, Patricio M; Prado, Jose L; Prieto, Alfredo; Douady, Christophe J; Stafford, Tom W; Willerslev, Eske; Orlando, Ludovic

    2015-03-01

    Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5 million years ago (Ma) until their extinction approximately 10 000 years ago. The evolutionary origin of the three known Hippidion morphospecies is still disputed. Based on palaeontological data, Hippidion could have diverged from the lineage leading to modern equids before 10 Ma. In contrast, a much later divergence date, with Hippidion nesting within modern equids, was indicated by partial ancient mitochondrial DNA sequences. Here, we characterized eight Hippidion complete mitochondrial genomes at 3.4-386.3-fold coverage using target-enrichment capture and next-generation sequencing. Our dataset reveals that the two morphospecies sequenced (H. saldiasi and H. principale) formed a monophyletic clade, basal to extant and extinct Equus lineages. This contrasts with previous genetic analyses and supports Hippidion as a distinct genus, in agreement with palaeontological models. We date the Hippidion split from Equus at 5.6-6.5 Ma, suggesting an early divergence in North America prior to the colonization of South America, after the formation of the Panamanian Isthmus 3.5 Ma and the Great American Biotic Interchange. PMID:25762573

  5. Etude séro-épidémiologique de la leishmaniose canine au centre du Maroc

    PubMed Central

    Fellah, Hajiba; Doughmi, Oursula; Maniar, Saâd; Lalami, Abdelhakim El Ouali

    2014-01-01

    Dans le monde, la leishmaniose viscérale humaine est connue pour avoir comme principale source d'infection les Canidés domestiques et sauvages. Au centre du Maroc, les données épidémiologiques, cliniques et parasitologiques sur la leishmaniose canine, sont quasiment inexistantes. Ce travail traite une étude prospective au cours de laquelle 61 sérums canins ont été analysés par un test rapide et par l'immunofluorescence indirecte. La sensibilité du test rapide par rapport à celle de l'immunofluorescence indirecte (IFI) est de 33,33%. La fréquence de la maladie chez les chiens s’élève à 9,83% (Test Rapide) et 24,59% (IFI). 73,33% des cas canins positifs à la sérologie sont asymptomatiques. Ce sont les jeunes chiens de moins de 5 ans qui sont les plus fréquemment atteints avec une sensibilité de la race Berger Allmand à l'infection. Cette étude a permis de mettre en évidence la présence de chiens leishmaniens (15 chiens séropositifs parmi 61) et de prouver l'existence du réservoir canin. Une stratégie de prévention active doit être mise en place. PMID:25852791

  6. Grave infarctus mésentérique par occlusion artérielle mésentérique supérieure chez un patient atteint de la maladie de Buerger

    PubMed Central

    Ratbi, Moulay Ibrahim; Abissegue, Ghislain Yves; Tarchouli, Mohamed; Tajedine, Mohammed Tariq

    2014-01-01

    La thromboangéite oblitérant ou maladie de Buerger, est une artérite inflammatoire non-artériosclérotique touchant classiquement les réseaux vasculaires périphériques des membres. Elle atteint principalement les hommes jeunes tabagiques et sans autres facteurs de risques cardiovasculaires. Les atteintes des artères digestives sont très rares et souvent fatales si elles ne sont pas évoquées et prises en charge précocement. Nous rapportons l'observation d'un jeune patient tabagique chronique qui s’était présenté aux urgences dans un tableau de péritonite aigue négligée due a un infarctus entero-mésentérique massif. L'origine était une ischémie mésentérique due à une thrombose de l'artère mésentérique supérieure. L’étude anatomopathologique avait objectivée une atteinte des artères digestive due à la maladie de Buerger. PMID:25918562

  7. Croissance des couches minces et des multicouches de matériaux supraconducteurs H Tboldmath_c : bilan et perspective

    NASA Astrophysics Data System (ADS)

    Contour, J. P.

    1994-11-01

    The main physical and chemical techniques of epitaxial growth of High T_c superconductor thin films are described together with their in situ analysis facilities and discussed with respect to their cost, sophistication and results (T_c, J_c growth defects, thickness and composition uniformity, crystallinity, electronic applications...). The future trends of the growth machines are then examined in connection with the present results and the development of superconductor electronics. Après la présentation des principales techniques de croissance physique et physicochimique de couches minces d'oxydes supraconducteurs à haute température critique, un bilan des résultats sera dressé par rapport aux différentes propriétés des films (transition résistive, courant critique, défauts de croissance, uniformité d'épaisseur et de composition, cristallinité...), aux difficultés de mise en œuvre et au coût de l'expérience. Les perspectives des différentes techniques seront ensuite examinées dans le cadre du développement potentiel d'une électronique utilisant les matériaux supraconducteurs H T_c.

  8. Problèmes de mesure d'adhérence de revêtement métallique sur substrat métallique

    NASA Astrophysics Data System (ADS)

    Silver, A.; Chassaing, E.; Goryachev, S. B.

    2003-03-01

    De tous les couples film/substrat, les systèmes métal/métal sont ceux qui présentent le plus de difficultés lorsqu'il s'agit de mesurer leur énergie d'adhérence. Les deux principales concernent d'une part leur caractère fortement adhérent, d'autre part la grande ductilité des matériaux mis en jeu. Parmi les nombreux tests mécaniques de mesure d'adhérence, les tests de rupture interfaciale, qui consistent à mesurer la résistance à la propagation d'une fissure interfaciale, sont les plus intéressants. Cependant, les tests de ce type les plus utilisés s'avèrent inadaptés aux interfaces métal/métal et un test original, le test de pelage avec cylindre en rotation, semble plus adéquat.

  9. Occlusion veineuse rétinienne et syndrome d'hyperviscosité

    PubMed Central

    Younes, Samar; Abdellaoui, Meriem; Zahir, Fadoua; Benatiya, Idriss A; Tahri, Hicham

    2015-01-01

    Les occlusions veineuses rétiniennes secondaires aux syndromes d'hyperviscosité sont rares. Plusieurs cas d'occlusion de la veine centrale de la rétine [OVCR] compliquant une hémopathie ont été décrits, principalement au cours des polycythémies primitives ou secondaires, des lymphomes ou des leucémies. A travers cette observation, nous rapportons le cas d'un patient qui présente une OVCR de l’œil droit survenant dans le cadre d'un myélome multiple. La rétinopathie du syndrome d'hyperviscosité est liée au ralentissement circulatoire qui affecte de manière prépondérante le secteur veineux et donne un aspect de rétinopathie de stase bilatérale, avec dilatation et tortuosité de l'ensemble des veines rétiniennes. A un certain degré d'hyperviscosité, une occlusion veineuse véritable peut survenir. Le traitement comprend la réhydratation, phlébotomie, et plasmaphérèse. PMID:25995806

  10. Solution saline hypertonique pour la bronchiolite chez les bébés

    PubMed Central

    Grewal, Simran; Goldman, Ran D.

    2015-01-01

    Résumé Question J’ai récemment reçu le rapport du congé de l’hôpital d’un patient de 1 an admis pour une bronchiolite. On y indiquait qu’il avait été traité, entre autres, avec une solution saline hypertonique inhalée. Cette thérapie est-elle recommandée pour les enfants en milieu de soins aigus? Réponse La bronchiolite, causée principalement par le virus respiratoire syncytial, est très commune en hiver. C’est la cause la plus fréquente d’hospitalisation durant l’enfance. Plusieurs bonnes études ont été effectuées au cours de la dernière décennie sur l’utilisation d’une solution saline hypertonique nébulisée pour la prise en charge de la bronchiolite; toutefois, leurs résultats sont conflictuels. Quoiqu’il puisse y avoir un rôle pour la solution saline hypertonique nébulisée chez les enfants hospitalisés pour une bronchiolite pendant plus de 3 jours, ce traitement dans d’autres milieux ne confère pas suffisamment de bienfaits pour recommander son utilisation.

  11. TRANSMISIÓN VERTICAL DE HTLV-1 EN EL PERÚ

    PubMed Central

    Villaverde, Jorge Alarcón; Romaní, Franco Romaní; Torres, Silvia Montano; Zunt, Joseph R.

    2012-01-01

    La infección por el virus linfotrópico humano de células T tipo 1 (HTLV-1) ha sido descrita en muchas áreas del mundo, como en los países del Caribe, Japón, África, Oceanía y en Sudamérica. En la presente revisión definimos la endemicidad del HTLV-1 en el país, planteando cuatro criterios epidemiológicos. Luego discutimos el tema central de la revisión: la transmisión vertical del HTLV-1, que en nuestro país sería uno de los principales mecanismos de transmisión. Dentro del desarrollo de este aspecto en particular, presentamos una estimación de la tasa de transmisión vertical y los factores de riesgo asociados con la transmisión vertical sobre la base de una revisión exhaustiva de estudios nacionales y extranjeros. Con esta revisión pretendemos dar una primera aproximación al estudio de la trasmisión vertical de HTLV-1, un aspecto poco estudiado en nuestro medio. PMID:21537777

  12. Traitement chirurgical à ciel ouvert des ruptures récentes du tendon calcanéen

    PubMed Central

    Mahdane, Hicham; Khaissidi, Abdesslam; Hammou, Nasserdine; Elidrissi, Mohammed; Mohamed, Shimi; Elibrahim, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Les ruptures du tendon calcanéen quelles soient sous cutanées ou par section direct sont de plus en plus fréquentes. Plusieurs techniques chirurgicales, qu'elles soient à ciel ouvert ou percutanées ont été mises au point pour traitée ce type de lésion. À travers une étude rétrospective descriptive sur la prise en charge chirurgicale des ruptures de tendon calcanéen fraiches. Nous avons analysé les résultats fonctionnels de 38 patients, tous opéré par une chirurgie à ciel ouvert. Les points forts de notre étude étaient l'absence de rupture itérative, principale complication du traitement chirurgicale des ruptures du tendon calcanéen, un faible taux de complications liées à la chirurgie à ciel ouvert, ainsi que les résultats fonctionnels satisfaisants. PMID:25419282

  13. Equivalent Thermal Conductivities for Twisted Flat Windings

    NASA Astrophysics Data System (ADS)

    Glises, R.; Bernard, R.; Chamagne, D.; Kauffmann, J. M.

    1996-10-01

    The authors of this paper intend to develop a method of determination of equivalent thermal conductivities for twisted flat windings. The conductivities determined are radial and parallel to the principal directions of the windings. A design has been realized thanks to the thermal modulus of the computation software Flux2D using a finite elements method. Following that phase, numerical correlations permitting to express the radial conductivities as a function of temperature, filling rate and insulation conductivities are proposed. Les auteurs de cet article se proposent de développer une étude de détermination de conductivités thermiques équivalentes d'empilements de bobinages plats torsadés. Les conductivités sont déterminées dans le plan radial (perpendiculaire à l'axe des bobinages) et parallèlement aux directions principales de la structure. La méthode utilisée est exclusivement numérique et est réalisée à l'aide du logiciel de calculs bidimensionnels par éléments finis Flux2D. Des corrélations numériques exploitables permettent d'obtenir directement les conductivités radiales en fonction du taux de remplissage, de la température du milieu et des conductivités des isolants électriques.

  14. Chargeur de batterie avec isolation galvanique et absorption sinusoïale

    NASA Astrophysics Data System (ADS)

    Rabasté, D.; Malartre, J. M.; Glaize, C.

    1995-11-01

    After a brief recall of converters conventionally used for battery chargers, this work stressed about a new structure with sinusoidal line current and galvanic insulation by a high frequency transformer working at 1 kW. The theoretical presentation is followed by the design problems, particularly over voltage on switches and transformations ratio choice. We describe next a power part converter model, and at last the experimental results. Après un bref rappel des structures classiquement utilisées pour les chargeurs de batteries, nous proposons l'étude d'une nouvelle structure à absorption sinusoïdale et isolement galvanique par transformateur haute fréquence fonctionnant à une puissance de 1 kW. A la suite d'une présentation théorique, nous passons à l'étude des principaux problèmes liés à la réalisation de ce convertisseur, principalement les surtensions aux bornes des interrupteurs et le choix d'un rapport de transformation présentant le meilleur compromis. Une modélisation de la partie puissance est ensuite décrite, avant de passer aux résultats obtenus.

  15. Mitochondrial genomes reveal the extinct Hippidion as an outgroup to all living equids

    PubMed Central

    Der Sarkissian, Clio; Vilstrup, Julia T.; Schubert, Mikkel; Seguin-Orlando, Andaine; Eme, David; Weinstock, Jacobo; Alberdi, Maria Teresa; Martin, Fabiana; Lopez, Patricio M.; Prado, Jose L.; Prieto, Alfredo; Douady, Christophe J.; Stafford, Tom W.; Willerslev, Eske; Orlando, Ludovic

    2015-01-01

    Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5 million years ago (Ma) until their extinction approximately 10 000 years ago. The evolutionary origin of the three known Hippidion morphospecies is still disputed. Based on palaeontological data, Hippidion could have diverged from the lineage leading to modern equids before 10 Ma. In contrast, a much later divergence date, with Hippidion nesting within modern equids, was indicated by partial ancient mitochondrial DNA sequences. Here, we characterized eight Hippidion complete mitochondrial genomes at 3.4–386.3-fold coverage using target-enrichment capture and next-generation sequencing. Our dataset reveals that the two morphospecies sequenced (H. saldiasi and H. principale) formed a monophyletic clade, basal to extant and extinct Equus lineages. This contrasts with previous genetic analyses and supports Hippidion as a distinct genus, in agreement with palaeontological models. We date the Hippidion split from Equus at 5.6–6.5 Ma, suggesting an early divergence in North America prior to the colonization of South America, after the formation of the Panamanian Isthmus 3.5 Ma and the Great American Biotic Interchange. PMID:25762573

  16. Tumeur d'Abrikossoff juxta axillaire: une localisation rare d'une tumeur très rare, à propos d'un cas

    PubMed Central

    Amourak, Sarah; Bouzoubaa, Wael; Jayi, Sofia; Alaoui, Fatimazahra Fdili; Chaara, Hikmat; Melhouf, Moulay Abdelilah

    2015-01-01

    Décrite pour la première fois en 1926 par Abrikossoff, les tumeurs à cellules granuleuses (TCG) sont bénignes et uniques dans la grande majorité des cas. Les principales localisations sont la cavité orale, puis les tissus sous-cutanés de la tête et du cou et les seins. La pathogenèse a été longtemps débattue, après avoir proposé initialement une origine musculaire striée les études récentes sont en faveur d'une origine neurogène schwannienne confirmées par une étude immunohistochimique. Le traitement de la tumeur à cellules granuleuses est un traitement chirurgical, il permet un diagnostic de certitude par l'examen anatomo-pathologique de la pièce d'exérèse qui doit rechercher les limites d'exérèse et la présence de critères de malignité. Leur évolution est souvent favorable si la résection chirurgicale est complète. Nous rapportons ici le cas d'une tumeur d'Abrikossoff à localisation juxta axillaire et nous profitons de faire une revue de la littérature afin de mettre le point sur cette entité rare. PMID:26328001

  17. Tumeur de Brenner maligne avec très bonne réponse après chimiothérapie: à propos d'un cas et revue de la littérature

    PubMed Central

    El Youbi, Meryam Ben Ameur; M'rabti, Hind; Mohtaram, Amina; Aaribi, Imane; Kharmoum, Jinane; El Khannoussi, Basma; Errihani, Hassan

    2014-01-01

    La tumeur de Brenner est une lésion ovarienne rare représentant 1 à 2% de l'ensemble des tumeurs ovariennes. Elle a été décrite pour la première fois par MacNaughton-Jones en 1898. La tumeur de Brenner maligne est une variante exceptionnelle survenant dans 2 à 5% des cas de tumeurs de Brenner. Nous proposons de discuter à partir d'une observation clinique de tumeur de Brenner maligne diagnostiquée chez une patiente de 47 ans traitée par chimiothérapie puis chirurgie radicale, et à travers une revue de la littérature; les différentes particularités cliniques et anatomo-pathologiques de cette entité rare ainsi que leurs implications diagnostiques et thérapeutiques. Le traitement repose principalement sur la chirurgie. L'indication d'une chimiothérapie adjuvante ou néo-adjuvante reste controversée. PMID:25328589

  18. Carcinome colloïde du sein: à propos d'un cas

    PubMed Central

    Laabadi, Kamilia; Jayi, Sofia; Alaoui, Fatimazohra Fdili; Bouguern, Hakima; Chaara, Hikmat; Melhouf, My Abdelilah

    2013-01-01

    Nous rapportons le cas d'une tumeur colloïde du sein chez un homme. Cette situation rare interpelle par son mode de découverte. Nous avons pris en charge un homme de 60 ans atteint d'une lésion rétro-aréolaire droite classée cliniquement T4b N1 M0 et suspecte radiologiquement. L'analyse histologique (microbiopsie) a conclu à un carcinome colloïde muqueux associé à une petite composante canalaire classique de grade I de SBR du sein. Les traitements complémentaires associent mastectomie, curage, chimiothérapie, radiothérapie et hormonothérapie. Le cancer du sein est rare chez l'homme. Le carcinome colloïde est exceptionnel puisqu'il représente seulement 1 à 6% de l'ensemble des cancers du sein. Il est encore plus rare chez l'homme. Ces tumeurs touchent une population spécifique et ont un meilleur pronostic que les autres types prépondérant dans les cancers du sein chez l'homme. A travers cette observation et une revue de la littérature, nous essaierons de discuter les principales caractéristiques anatomo-cliniques et évolutives de cette forme rare du cancer du sein. PMID:24772222

  19. Complication rare de la coloscopie chez un patient sous anticoagulant: hemopéritoine par rupture d'un hématome sous capsulaire de la rate, cas clinique

    PubMed Central

    Sbai, Hicham; Boukatta, Brahim; El Bouazzaoui, Abderahim; Youssfi, Mounia; Mellouki, Ihsane; Benajeh, Dafr Allah; Bobo, Meriem; Bohadouti, Hicham; Tizniti, Siham; Ibrahimi, Adil; Taleb, Khalid Ait; Kanjaa, Nabil

    2015-01-01

    La coloscopie à visée diagnostique et/ou thérapeutique est un examen invasif fréquemment pratiquée de nos jours. La perforation colique et l'hémorragie digestive en sont les principales complications. La survenue d'un hémopéritoine par rupture d'un hématome sous-capsulaire splénique est une complication extrêmement rare et potentiellement mortelle de la coloscopie. Un traumatisme splénique minime passé inaperçu et la prise d'anticoagulant en sont des facteurs favorisants. Nous présentons le cas d'une rupture d'un hématome sous-capsulaire de la rate après une coloscopie, survenue chez un patient de 70 ans porteur d'une valve mitrale mécanique sous acénocoumarol à dose hypocaogulante. La nécessité d'obtention d'une anti coagulation rapidement efficace et l'instabilité hémodynamique avaient justifiée la réalisation d'une splénectomie. L’évolution était favorable. A travers cette observation clinique nous discutons les mécanismes et les modalités de prise en charge devant cette complication. PMID:26523174

  20. Unificando los criterios de sepsis neonatal tardía: propuesta de un algoritmo de vigilancia diagnóstica

    PubMed Central

    Zea-Vera, Alonso; Turin, Christie G.; Ochoa, Theresa J.

    2015-01-01

    Las infecciones constituyen una de las principales causas de muerte en el periodo neonatal. El diagnóstico de sepsis neonatal representa un gran desafío ya que los recién nacidos presentan signos clínicos muy inespecíficos y los exámenes auxiliares tienen una baja sensibilidad. Con el objetivo de mejorar el diagnóstico correcto de esta patología proponemos un algoritmo de vigilancia diagnóstica para sepsis neonatal tardía en el Perú y países de la región. El algoritmo permite clasificar a los episodios como sepsis confirmada, probable o posible, y sobretodo busca identificar aquellos episodios que no corresponden a sepsis, evitando calificar otras patologías como “sepsis”. Un mejor diagnóstico permitiría tener tasas más reales de sepsis neonatal, mejorar el uso de antibióticos y evitar sus efectos negativos en el recién nacido, así como una visión más exacta de su impacto en la salud pública. PMID:25123879

  1. Une hanche douloureuse révélatrice d'une histiocytose osseuse multifocale

    PubMed Central

    Lahrach, Kamal; Alaoui, Adil; el Kadi, Khalid Ibn; Marzouki, Amine; Boutayeb, Fawzi

    2014-01-01

    L'histiocytose langerhansienne est une maladie rare qui touche principalement l'enfant et l'adulte jeune. Elle peut prendre plusieurs aspects, L'atteinte osseuse peut être uni- ou multifocale. Nous rapportons une observation d'histiocytose langerhansienne osseuse multifocale, révélée chez un patient âgé de 23 ans et ayant touché le col fémoral droit. La scintigraphie osseuse a permis de retrouver plusieurs localisations: l'os temporal, humérale et scapulaire droite. En raison du risque fracturaire, le patient a bénéficié d'une ostéosynthèse par vis-plaque DHS avec curetage biopsie de la lésion. L'examen histologique a révélé une histiocytose langerhansienne. L'évolution fut favorable après chimiothérapie par voie générale. PMID:25018840

  2. Global evolution of Equidae and Gomphotheriidae from South America.

    PubMed

    Prado, José L; Alberdi, María T

    2014-08-01

    The contemporary South American mammalian communities were determined by the emergence of the Isthmus of Panama and by the profound climatic oscillations during the Pleistocene. Horses and gomphotheres were 2 very conspicuous groups of immigrant mammals from North America that arrived in South America during the Pleistocene. The present study compiles updated data on the phylogeny, systematics and ecology of both groups in South America. The horses in South America are represented by 2 genera, Hippidion and Equus, as are the gomphotheres, represented by Cuvieronius and Stegomastodon. Both genera of horses include small (Hippidion devillei, H. saldiasi, E. andium and E. insulatus) and large forms (Equus neogeus and H. principale), which dispersed into South America using 2 different routes. The possible model for this dispersion indicates that the small forms used the Andes corridor, while larger horses dispersed through the eastern route and through some coastal areas. In the case of gomphotheres, Cuvieronius and Stegomastodon reached South America in 2 independent dispersal events, and Cuvieronius dispersed across the Andean corridor, while large Stegomastodon spread along the eastern route. Horses and gomphotheres present values of δ(13) C from woodlands to C4 grasslands. Hippidion present lower values of δ(13) C than Equus in the late Pleistocene, whereas the gomphotheres diverge from value of δ(18) O, reflecting that Cuvieronius inhabited the Andean corridor and Stegomastodon dispersed through eastern plains. The gomphothere and horse species recorded in South America became extinct around the time that humans arrived. PMID:25236414

  3. Mariage consanguin et morbi-mortalité, courte revue de la littérature à partir d'une association exceptionnelle: syndrome de Usher et Neurofibromatose de Von Recklinghausen

    PubMed Central

    Atipo-Tsiba, Pépin-Williams

    2016-01-01

    Le syndrome de Usher est défini par l'association d'une surdité de perception congénitale de sévérité variable évolutive ou non et d'une rétinopathie pigmentaire progressivement cécitante. La Neurofibromatose de Von Recklinghausen ou Neurofibromatose de type I est la principale forme clinique des neurofibromatoses avec environ 90% des cas. Ces deux maladies sont d'origine génétique avec des prévalences très basses. La probabilité pour qu'un seul et même individu souffre à la fois de ces maladies est exceptionnelle. Comme toutes les maladies génétiques, la consanguinité augmente de façon assez sensible la probabilité de leur apparition. Le mariage consanguin est encore largement répondu au Maghreb et dans certaines régions d'Afrique de l'Ouest. Cette observation rapporte un cas exceptionnel de cette association chez un homme de 40 ans originaire de la Mauritanie né d'une union consanguine. PMID:27231508

  4. Un faux kyste pancréatique mimant une tumeur kystique et doublement compliqué de compression digestive et d'hémorragie: la pancréatite aiguë, la saga continue

    PubMed Central

    Ameuraoui, Taoufiq; Alami, Baderedine; Boubbou, Meryem; Maaroufi, Mustapha; Kamaoui, Imane; Tizniti, Siham

    2014-01-01

    L'histoire naturelle des pancréatites aigues nécrotico-hémorragiques est parfois caractérisée par la survenue imprévisible de plusieurs complications. La formation de pseudos kystes constitue un tournant évolutif important lors de sa survenue. Son évolution est imprévisible pouvant aller de la simple résorption spontanée à la survenue de complications gravissimes. Les principales complications observées sont l'obstruction, la surinfection et l'hémorragie. Nous rapportons le cas d'une pancréatite aigue lithiasique compliquée d'un faux kyste de pancréas compressif et d'un faux anévrysme artériel. L'intérêt de cet observation réside d'une part dans l'originalité de la présentation clinique, du fait que l'histoire naturelle de cette affection n'est pas toujours connue, ce qui pose parfois des difficultés diagnostic et justifie une discussion pluridisciplinaire, et d'autre part dans la rareté des cas publiés avec, à la fois, des complications hémorragique,et compressive: digestive et canalaires biliaires. PMID:25422696

  5. La tachycardie supraventriculaire chez l’enfant

    PubMed Central

    Bellavance, Marc

    2001-01-01

    La tachycardie supraventriculaire est l’arythmie symptomatique la plus fréquente chez l’enfant. Ainsi, le pédiatre a avantage à se familiariser avec ce problème. De nombreux progrès ont été réalisés récemment. Les mécanismes physiopathologiques sont mieux connus, et les options pharmacologiques plus variées. De plus, il est possible d’offrir un traitement curatif avec l’ablation par cathéter. Le présent article résume ce trouble du rythme cardiaque sous différents aspects, soit la définition, l’épidémiologie, les différentes catégories (principalement le syndrome de Wolff-Parkinson-White et la tachycardie de réentrée par le nœud auriculoventriculaire), les manifestations cliniques, le diagnostic différentiel, les options thérapeutiques et le pronostic. PMID:20084129

  6. Applications médicales de la cryogénie et de la supraconductivité. La spectroscopie de résonance magnétique nucléaire

    NASA Astrophysics Data System (ADS)

    Baverel, Gabriel; Briguet, André

    1991-02-01

    This short review concerns the use of cryogenics and superconductivity in biomedical nuclear magnetic resonance (NMR) spectroscopy studies. The main developments presented are based on the use of phosphorus 31 and carbon 13 NMR spectroscopy to study normal and pathologic muscle metabolism in man and of proton to study the tissue content of water, lipids and lactate. Some information is given on the technical characteristics and price of the magnets used for biomedical NMR spectroscopy. Cette courte revue traite de l'utilisation de la cryogénie et de la supraconductivité dans les études biomédicales par spectroscopie de résonance magnétique nucléaire (RMN). Les principales applications présentées sont basées sur l'utilisation de la spectroscopie RMN du phosphore 31 et du carbone 13 pour étudier le métabolisme musculaire normal et pathologique chez l'homme ainsi que du proton pour mesurer le contenu tissulaire en eau, lipides et lactate. Quelques informations sont données sur les caractéristiques techniques et le prix des aimants utilisés pour la spectroscopie RMN biomédicale.

  7. Correlated-electron bands and interlayer pairing in high-temperature superconductors

    NASA Astrophysics Data System (ADS)

    Ashkenazi, J.; Kuper, C. G.

    The conduction electrons in YBa2Cu3O7- δ are shown to derive mainly from 02-03 p-orbitals ; they lie in a narrow band (of width ˜ 0.1 eV). The Cooper pairs in the superconducting state come from two distinct CuO2 planes, and the glue which binds them is an electronic breathing mode of charge transfer within an interplanar O4-Cu1-O4 complex. Because the paired electrons are on different planes, the Coulomb repulsion between them is small, and is not inimical to superconductivity. Our picture is consistent with experiment. On montre que les electrons de conduction dans YBa2Cu3O7-δ proviennent principalement des orbitales p des atomes 02 et 03 ; ils se situent dans une bande étroite (de largeur ˜ 0,1 eV). Les paires de Cooper dans l'état supraconducteur viennent de deux plans CuO2 distincts, et la glu qui les lie est un mode électronique de transfert de charge dans les complexes interplanaires O4-Cu1-O4. Du fait que les électrons appariés sont dans des plans différents, la répulsion coulombienne entre eux est faible et ne s'oppose pas à la supraconductivité. Notre modèle est en accord avec l'expérience.

  8. Evolución Dinámica de Cúmulos Estelares Abiertos

    NASA Astrophysics Data System (ADS)

    de La Fuente Marcos, R.

    Las estrellas que observamos no se formaron aisladamente, sino que lo hicieron en grupos o cúmulos. Estos sistemas estelares recibenel nombre de cúmulos estelares abiertos o galácticos cuando están constituidos por estrellas de la Población I. Los cúmulos abiertos se localizan preferentemente en el plano galáctico, y en muchos de ellos está teniendo lugar aún una activa formación estelar. El propósito principal de esta tesis doctoral es el estudio de la evolución dinámica de estos sistemas estelares por medio de simulaciones numéricas y de la comparación de sus resultados con datos observacionales. Con este fin se analizan los efectos que, sobre la dinámica de los cúmulos, ejercen varios fenómenos de interés astrofísico tales como el campo gravitatorio galáctico, la pérdida de masa causada por la evolución estelar y la presencia de binarias primordiales. En este trabajo se presentan los resultados de más de un centenar de modelos de cúmulos, con poblaciones comprendidas en el intervalo [100, 10.000] estrellas, calculados con NBODY5, un programa estándar en el campo de la Dinámica Estelar Experimental. De los mismos se deduce que el mecanismo principal que rige la dinámica de los cúmulos abiertos es la evolución estelar de su distribución de masas, encontrándose un comportamiento diferencial fuertemente dependiente de la población inicial del cúmulo. Los mecanismos responsables de la desintegración de los cúmulos abiertos son analizados en detalle, proponiéndose un modelo analítico que ajusta razonablemente los resultados de las simulaciones. Además, y con el fin de explicar el elevado número de sistemas múltiples observados en cúmulos abiertos, se estudian los efectos que, sobre los mismos, ejerce la presencia de una cierta fracción de binarias primordiales. El papel de las binarias tambiín depende de la riqueza del cúmulo y sus efectos se interrelacionan con aquellos debidos a la evolución estelar. Por último, se aborda la posibilidad de construir diagramas de Hertzsprung-Russell teóricos a partir de las simulaciones y compararlos con datos procedentes de cúmulos abiertos reales.

  9. Simulação de ejeções de massa coronal

    NASA Astrophysics Data System (ADS)

    Corsini, M. A.; Silva, A. V. R.

    2003-08-01

    Ejeções de massa coronal (EMC) são bolhas gigantes de gás permeadas por campos magnéticos que são ejetadas do Sol durante um período de várias horas. Caso estas ejeções atinjam a Terra, geralmente, causam uma série de distúrbios às comunicações de longa distância e navegação, além de danos a satélites e transformadores. Portanto, é desejável que sejamos capazes de prever quando estas ejeções atingirão a Terra. Para tanto, é necessário um bom entendimento dos mecanismos causadores das ejeções e, principalmente, de como se dá a propagação das EMC e sua interação com o vento solar que permeia o meio interplanetário. Nesse sentido foi desenvolvido um programa computacional para resolver as equações MHD (Magneto-Hidro-Dinâmica) que regem a evolução das EMC. Primeiramente foram estabelecidas as condições necessárias para descrever o vento solar, no estado estacionário, que permeia todo o meio interplanetário. Num primeiro momento, resolveu-se o sistema de equações para o caso do vento isotérmico, conhecida como a solução de Parker, a fim de testarmos o modelo. Então, foi considerado o caso do vento solar com temperatura variável no meio interplanetário. Este resultado foi utilizado como a base de nosso sistema em seu instante inicial. Posteriormente foram feitas as considerações necessárias para descrever a propagação da Ejeção de Massa Coronal. As EMC foram simuladas como um aumento de densidade e temperatura local na coroa solar. A órbita e a posição da Terra foram incluídas no sistema. Os dados gerados possibilitaram uma análise da evolução da EMC pelo meio interplanetário até encontrar-se com a Terra. Os perfis de densidade e temperatura a 1 Unidade Astronômica são comparados com os dados de satélites reportados na literatura.

  10. Delivering genetic education and genetic counseling for rare diseases in rural Brazil.

    PubMed

    Acosta, A X; Abé-Sandes, K; Giugliani, R; Bittles, A H

    2013-12-01

    Brazil is the largest country in Latin America, with an ethnically diverse, Portuguese-speaking and predominantly Roman Catholic population of some 194 million. Universal health care is provided under the Federal Unified Health System (Sistema Único de Saúde) but, as in many other middle and low income countries, access to medical genetics services is limited in rural and remote regions of the country. Since there is no formally recognized Genetic Counseling profession, genetic counseling is provided by physicians, trained either in medical genetics or a related clinical discipline. A comprehensive medical genetics program has been established in Monte Santo, an inland rural community located in the state of Bahia in Northeast Brazil, with high prevalences of a number of autosomal recessive genetic disorders, including non-syndromic deafness, phenyketonuria, congenital hypothyroidism and mucopolysaccharidosis VI (Maroteaux-Lamy syndrome). Genetic education, counseling and treatment are locally provided, with a neonatal screening program for MPSVI currently under trial. PMID:23338802

  11. [Historical notes about scientific research in the Instituto Mexicano del Seguro Social.

    PubMed

    Zárate, Arturo; Basurto-Acevedo, Lourdes

    2013-01-01

    Medical research in the Instituto Mexicano del Seguro Social has been considered one of the most important in this country for quality and quantity. Thanks to the work and leadership of Benito Coquet, who initiated the building of the National Medical Center in 1961, and the work of two pillars of research, Luis Castelazo and Bernardo Sepúlveda, the Institute successfully improved scientific research. In the years that followed, the Institute fostered the professionalization of research, the creation of research units in different areas of science, the incorporation of consolidated groups of researchers, the relationship with other institutions, the incorporation to the Sistema Nacional de Investigadores, the editing of a journal to expose outside the work done within the Institute, and the formation of a trust to raise funds for financing. Thanks to all that, institutional research strengthened in all lines, and it was placed first, at certain times, at the national level. PMID:24290017

  12. Análisis del espectro infrarrojo del polvo interestelar asociado con cúmulos globulares y de su evolución temporal

    NASA Astrophysics Data System (ADS)

    Pellizza, L. J.; Forte, J. C.; Carpintero, D.

    El trabajo que se presenta investiga la dinámica de las partículas de polvo interestelar eyectadas por estrellas gigantes rojas en un cúmulo globular utilizando simulaciones numéricas de su interacción con el campo gravitatorio y con la radiación electromagnética de las estrellas. Se pretende con ello determinar la distribución espacial de ese material como una función del tiempo en un sistema similar a NGC 104 (47 Tuc). A partir de la distribución espacial resultante se obtuvo el espectro infrarrojo integrado el cual sugiere que el máximo contraste con la radiación estelar ocurre en longitudes de onda cercanas a 300 μm y que decrece rápidamente hacia longitudes de onda menores, en las que suelen realizarse las observaciones.

  13. Production and quality assurance in the SIT Africa Mediterranean fruit fly (Diptera: Tephritidae) rearing facility in South Africa

    SciTech Connect

    Barnes, B.; Rosenberg, S.; Arnolds, L.; Johnson, J.

    2007-03-15

    A mass-rearing facility for Mediterranean fruit fly Ceratitis capitata (Wiedemann) was commissioned in Stellenbosch in 1999 to produce sterile male fruit flies for a sterile insect technique (SIT) project in commercial fruit orchards and vineyards in the Western Cape province of South Africa. The mass-rearing procedure was largely based on systems developed by the FAO/IAEA Agriculture and Biotechnology Laboratory, Seibersdorf, Austria. A number of genetic sexing strains were used to produce only males for release. Initial cramped rearing and quality management conditions were alleviated in 2001 with the construction of a new adult rearing room and quality control laboratory. In 2002 a comprehensive Quality Management System was implemented, and in 2003 an improved genetic sexing strain, VIENNA 8, was supplied by the FAO/IAEA Laboratory in Seibersdorf. For most of the first 3 years the facility was unable to supply the required number of sterile male Mediterranean fruit flies for the SIT program without importing sterile male pupae from another facility. From mid-2002, after the quality management system was implemented, both production and quality improved but remained below optimum. After the introduction of the VIENNA 8 genetic sexing strain, and together with an improvement in the climate control equipment, production stability, and quality assurance parameters improved substantially. The critical factors influencing production and quality were an inadequate rearing infrastructure, problems with the quality of the larval diet, and the initial absence of a quality management system. The results highlight the importance of effective quality management, the value of a stable and productive genetic sexing strain, and the necessity for a sound funding base for the mass-rearing facility. (author) [Spanish] La facilidad para criar en masa la mosca mediterranea de la fruta, Ceratitis capitata (Wiedemann) fue comisionada en Stellenbosch en 1999 para producir machos esteriles de moscas para el proyecto de la tecnica del insecto esteril (TIE) en huertos de frutos y vinas comerciales en la provincia del Cabo Occidental del Sudafrica. El procedimiento de criar en masa fue en su mayor parte basado en los sistemas desarrollados por el Laboratorio de Agricultura y Biotecnologia de la FAO/IAEA, Seibersdorf, Austria. Un numero de razas que separara los sexos geneticamente fueron utilizadas para producir solo machos para la liberacion. La congestionada condicion inicial para criar las moscas y su manejo de calidad fueron aliviadas en 2001 con la construccion de un nuevo cuarto de cria para adultos y un laboratorio de control de calidad. En 2002, un Sistema de Manejo de Calidad comprensivo fue implementado, y en 2003 una raza mejorada que separa los sexos geneticamente, VIENNA 8, fue proveido por el Laboratorio de la FAO/IAEA en Seibersdorf. En la mayor parte de los primeros 3 anos la facilidad no pudo suplir el numero requerido de machos esteriles de la mosca mediterranea de la fruta para el programa de TIE sin la necesidad para importar machos esteriles de otra facilidad. Desde medio del ano de 2002, despues que el sistema de manejo de calidad fue implementado, la produccion y la calidad mejoraron pero aun quedaron por debajo del nivel optimo. Despues de la introduccion de la raza VIENNA 8 que separa los sexos geneticamente, y junto con el equipo mejorado de control de clima, la estabilidad y los parametros de seguridad de calidad mejoraron substancialmente. Los factores criticos que influyeron en la produccion y la calidad fueron la infraestructura inadecuada para criar las moscas, problemas con la calidad de la dieta para las larvas y la ausencia inicial de un sistema de manejo de calidad. Los resultados muestran claramente la importancia de un manejo efectivo de la calidad, el valor de una raza productiva que separa los sexos geneticamente y la necesidad de contar con una base solida de financimiento para la infraestructura de una cria en masa. (author)

  14. [An information system for injuries from external causes (SILEX): a successful project in El Salvador].

    PubMed

    Salinas, Oscar; de Cosío, Gerardo; Clavel-Arcas, Carme; Montoya, Jeannette; Serpas, Mario; Morán de García, Silvia; Concha-Eastman, Alberto

    2008-12-01

    This article examines the stages in developing an information system for injuries from external causes (Sistema de Información de Lesiones de Causa Externa-SILEX), as well as its limitations and achievements. SILEX is a Web-based application for collection, quality control, presentation, and analysis of data available from the hospital system for surveillance of injuries from external causes created by Ministry of Health of El Salvador with data from the hospital emergency services. This system maintains comprehensive information on the injured person-type of injury, intention, injury site, activity being performed at the time of injury, risk factors, etc.-in the form of tables, graphs, and maps, which streamlines the development of intervention plans and prevention initiatives for these types of injuries in El Salvador. This experience is an example of what can be done to close the information gap on injuries by external causes in the Region of the Americas. PMID:19178778

  15. Constructing a New Vision: Undoing Gender through Secondary Education in Honduras

    NASA Astrophysics Data System (ADS)

    Murphy-Graham, Erin

    2009-11-01

    This article presents results from a qualitative study on how the Honduran secondary education programme, Sistema de Aprendizaje Tutorial (SAT), attempts to "undo gender" (Deutsch 2007: 122) by encouraging students to rethink gender relations in their everyday lives in a way that reflects their increased consciousness of gender equality. My findings suggest that SAT increased women's gender consciousness and this heightened their desire for change in the domestic sphere. In some instances, women were able to negotiate a new sharing of responsibilities with their spouses. There are several features of SAT that make it a transformative innovation in education: (1) gender is mainstreamed into the curriculum; (2) gender is linked with the larger concept of justice; (3) students engage in reflection, dialogue and debate; (4) teachers are given the opportunity to reflect critically on their understanding of gender in professional development sessions; and (5) it emphasises that undoing gender requires change among individuals and in social structures such as the family.

  16. Reflexión bioética sobre el uso de organismos genéticamente modificados

    PubMed Central

    Yunta, Eduardo Rodríguez

    2011-01-01

    El presente artículo reflexiona desde los 4 principios de la bioética el uso comercial de organismos genéticamente modificados. Se cuestiona fundamentalmente la falta de transferencia de tecnología entre el mundo desarrollado y en desarrollo y el que el presente sistema de patentamiento de organismos vivos modificados fomenta intereses comerciales y no da debida importancia al desarrollo sostenible de la agricultura y ganadería en los países en desarrollo, donde más se necesita. Se reflexiona sobre la importancia que tiene evaluar los riesgos antes de introducirse en el mercado organismos genéticamente modificados y la necesidad de regulación en los países. PMID:21927675

  17. Cajal and consciousness. Introduction.

    PubMed

    Marijuán, P C

    2001-04-01

    One hundred years after Santiago Ramón Cajal established the bases of modern neuroscience in his masterpiece Textura del sistema nervioso del hombre y de los vertebrados, the question is stated again: What is the status of consciousness today? The responses in this book, by contemporary leading figures of neuroscience, evolution, molecular biology, computer science, and quantum physics, collectively compose a fascinating conceptual landscape. Both the evolutionary emergence of consciousness and its development towards the highest level may be analyzed by a wealth of new theories and hypotheses, including Cajal's prescient ones. Some noticeable gaps remain, however. Celebrating the centennial of Textura is a timely occasion to reassess how close--and how far--our system of the sciences is to explaining consciousness. PMID:11349418

  18. The new Venezuelan national control center

    SciTech Connect

    Beluche, C.M.

    1984-07-01

    This paper describes the actual status of the Venezuelan Electric Power System, the different operational areas involved, and finally the Interconnected System. Due to the development in the Power System, and in order to perform a more reliable and economic operation, it was established the need to implement a new supervisory system, for the Interconnected System Control Center. Also is described the system for the new control center for Oficina de Operacion de Sistemas Interconectados (OPSIS). OPSIS will monitor the Bulk Transmission Network (BTN), and will exchange information and control with the Regional Dispatch Centers through the computer network. The Regional Dispatch Center (RDC) shall have the responsibility to accomplish the control order. The Bulk Transmissions System consists of that portion of the system from 800 KV to 230 KV. A total of six RDCs will be included in the system.

  19. Cost analysis of nucleic acid amplification for diagnosing pulmonary tuberculosis, within the context of the Brazilian Unified Health Care System

    PubMed Central

    Pinto, Márcia; Entringer, Aline Piovezan; Steffen, Ricardo; Trajman, Anete

    2015-01-01

    ABSTRACT We estimated the costs of a molecular test for Mycobacterium tuberculosis and resistance to rifampin (Xpert MTB/RIF) and of smear microscopy, within the Brazilian Sistema Único de Saúde (SUS, Unified Health Care System). In SUS laboratories in the cities of Rio de Janeiro and Manaus, we performed activity-based costing and micro-costing. The mean unit costs for Xpert MTB/RIF and smear microscopy were R$35.57 and R$14.16, respectively. The major cost drivers for Xpert MTB/RIF and smear microscopy were consumables/reagents and staff, respectively. These results might facilitate future cost-effectiveness studies and inform the decision-making process regarding the expansion of Xpert MTB/RIF use in Brazil. PMID:26785963

  20. Origen y evolución de la estructura del Universo

    NASA Astrophysics Data System (ADS)

    García Lambas, D.

    Se presenta una revisión de diversos tópicos vinculados a la evolución de estructuras en el Universo y se discuten los escenarios más aceptados para la comprensión de las irregularidades primigenias y de su evolución temporal. Se analizan evidencias observacionales de la naturaleza jerárquica en los mecanismos de formación de sistemas, tales como las indicaciones provenientes de las correlaciones espaciales y de velocidades, la naturaleza del Universo a alto redshift, y la habilidad de los modelos jerárquicos en predecir diversas propiedades dinámicas, fotométricas y químicas de las galaxias.

  1. Microphone interlaboratory comparison in the Americas

    NASA Astrophysics Data System (ADS)

    Wong, George S. K.; Wu, Lixue

    2002-11-01

    The final results of a Sistema Interamericano de Metrologia (SIM) interlaboratory comparison on microphone calibration are presented. Initially the comparison involved NORAMET countries: USA, Canada, and Mexico. Later, the comparison was extended to include Argentina and Brazil, resulting in a SIM AUV.A-K1 microphone interlaboratory comparison. The National Metrology Institutes (NMIs) of the five American countries that participated were the Institute for National Measurement Standards (INMS--Canada), National Institute of Standards and Technology (NIST--USA), Centro Nacional de Metrologia (CENAM--Mexico), Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO--Brazil) and Unidad Tecnica Acustica, (INTI--Argentina). INMS, Canada was the pilot laboratory that provided the data for the final report. The maximum rms deviation for the two LS1P laboratory standard microphones measured by the above participants is 0.037 dB that may be considered as the key comparison reference value.

  2. The type specimens of Calyptratae (Diptera) housed in non-traditional institutions in Argentina.

    PubMed

    Patitucci, Luciano Damián; Mulieri, Pablo Ricardo; Domínguez, M Cecilia; Mariluis, Juan Carlos

    2015-01-01

    The type material of species of Calyptratae Diptera belonging to Anthomyiidae, Calliphoridae, Fanniidae, Muscidae, Sarcophagidae, and Tachinidae, housed in the collections of non-traditional institutions in Argentina were examined. These collections were included in the recently created "Sistema Nacional de Datos Biológicos" (National Biological Data System). We examined four collections: "Administración Nacional de Laboratorios e Institutos de Salud 'Dr. Carlos G. Malbrán'" (ANLIS), "Instituto Nacional de Tecnología Agropecuaria, Castelar, Buenos Aires" (INTA), "Instituto Argentino de Investigaciones de las Zonas Áridas" (IADIZA); and "Fundación Félix de Azara" (CFA). Comparison of the original descriptions of these species with the label information revealed the existence of 24 holotypes, 5 lectotypes, 11 syntypes, and 441 paratypes/paralectotypes. Complete information is given for each type, including reference to the original description, label data, and preservation condition.  PMID:25661231

  3. Risk assessment of sewer condition using artificial intelligence tools: application to the SANEST sewer system.

    PubMed

    Sousa, V; Matos, J P; Almeida, N; Saldanha Matos, J

    2014-01-01

    Operation, maintenance and rehabilitation comprise the main concerns of wastewater infrastructure asset management. Given the nature of the service provided by a wastewater system and the characteristics of the supporting infrastructure, technical issues are relevant to support asset management decisions. In particular, in densely urbanized areas served by large, complex and aging sewer networks, the sustainability of the infrastructures largely depends on the implementation of an efficient asset management system. The efficiency of such a system may be enhanced with technical decision support tools. This paper describes the role of artificial intelligence tools such as artificial neural networks and support vector machines for assisting the planning of operation and maintenance activities of wastewater infrastructures. A case study of the application of this type of tool to the wastewater infrastructures of Sistema de Saneamento da Costa do Estoril is presented. PMID:24552736

  4. Antimicrobial susceptibilities and capsular types of invasive Streptococcus pneumoniae isolated in children in Mexico City.

    PubMed

    Echániz-Aviles, G; Velázquez-Meza, M E; Carnalla-Barajas, M N; Soto-Noguerón, A; Solórzano-Santos, F; Pérez Miravete, A; Gatica-Marquina, R; di Fabio, J L

    1997-01-01

    As part of the Sistema Regional de Vacunas (SIREVA) initiative, we conducted a surveillance study to determine the relative prevalence of capsular types of Streptococcus pneumoniae and antimicrobial susceptibility of invasive isolates in children less than 5 years old. We collected 220 isolates and found 33 of the 90 known types, with type 23F as the most common followed by types 6A+B, 14, 19F, and 19A. High penicillin resistance was found in 49 strains (22.2%), 31 belonging to type 23F. Twenty-nine (13.1%) were resistant to erythromycin, 95 (43.1%) were resistant to chloramphenicol, and 24 (10.9%) were resistant to cefotaxime. No strains were resistant to vancomycin. PMID:9185143

  5. POBREZA Y VULNERABILIDAD EN MÉXICO: EL CASO DE LOS JÓVENES QUE NO ESTUDIAN NI TRABAJAN*

    PubMed Central

    Aguila, Emma; Mejía, Nelly; Pérez, Francisco; Rivera, Alfonso; Ramírez, Edgar

    2015-01-01

    La situación de los jóvenes que no estudian ni trabajan (ninis) se ha vuelto evidente en los últimos años debido a los riesgos que enfrenta dicha población. Este artículo contribuye a la literatura al analizar las características económicas y laborales de los ninis, explora la situación laboral de sus parejas y provee proyecciones al año 2030. Asimismo, propone una clasificación de ninis para focalizar el diseño de políticas públicas, que identifica una tendencia a la baja de éstos debido a las mujeres que acceden al sistema educativo y al mercado laboral y que una mayor proporción de esta población estará compuesta por desempleados. PMID:25918452

  6. Cost analysis of nucleic acid amplification for diagnosing pulmonary tuberculosis, within the context of the Brazilian Unified Health Care System.

    PubMed

    Pinto, Márcia; Entringer, Aline Piovezan; Steffen, Ricardo; Trajman, Anete

    2015-01-01

    We estimated the costs of a molecular test for Mycobacterium tuberculosis and resistance to rifampin (Xpert MTB/RIF) and of smear microscopy, within the Brazilian Sistema Único de Saúde (SUS, Unified Health Care System). In SUS laboratories in the cities of Rio de Janeiro and Manaus, we performed activity-based costing and micro-costing. The mean unit costs for Xpert MTB/RIF and smear microscopy were R$35.57 and R$14.16, respectively. The major cost drivers for Xpert MTB/RIF and smear microscopy were consumables/reagents and staff, respectively. These results might facilitate future cost-effectiveness studies and inform the decision-making process regarding the expansion of Xpert MTB/RIF use in Brazil. PMID:26785963

  7. Estudio dinámico de un potencial perturbador dependiente de dos parámetros

    NASA Astrophysics Data System (ADS)

    Miloni, O.; Brunini, A.

    El objeto del presente trabajo consiste en el estudio dinámico de un sistema dinámico caracterizado por la función hamiltoniana correspondiente a un satélite planetario perturbado por la acción del Sol y del achatamiento del planeta madre. Cuando dicha Hamiltoniana se promedia respecto de los términos de corto período, esta queda con dos grados de libertad, y su estudio puede ser realizado con las herramientas clásicas de la dinámica no-lineal. Se tratará de determinar regiones regulares y caóticas de movimiento. En el caso de estas últimas, es de particular interés la determinación de su orígen.

  8. H3+: superficies de energía potencial, estados y transiciones rovibracionales

    NASA Astrophysics Data System (ADS)

    Aguado, M. Paniagua Y. A.

    Hemos calculado varias superficies globales de energía potencial para el estado fundamental y excitados del sistema H3+ en más de ocho mil geometrías diferentes usando una base (9s 3p 1d)/[4s 3p 1d] en cada átomo de Hidrógeno y mediante un método de cálculo de interacción de configuraciones completa (FCI). Hemos ajustado las superficies a formas analíticas del tipo Aguado y Paniagua con un error promedio menor de 50 cm-1 y menor en el pozo de potencial del estado fundamental. Finalmente hemos calculado y analizado los niveles vibracionales para los dos estados electrónicos más bajos, siendo la desviación respecto de los mejores valores publicados, tanto experimentales como teóricos, de unos pocos números de onda.

  9. PubMed

    Yunta, Eduardo Rodríguez

    2010-01-01

    El presente artículo reflexiona desde los 4 principios de la bioética el uso comercial de organismos genéticamente modificados. Se cuestiona fundamentalmente la falta de transferencia de tecnología entre el mundo desarrollado y en desarrollo y el que el presente sistema de patentamiento de organismos vivos modificados fomenta intereses comerciales y no da debida importancia al desarrollo sostenible de la agricultura y ganadería en los países en desarrollo, donde más se necesita. Se reflexiona sobre la importancia que tiene evaluar los riesgos antes de introducirse en el mercado organismos genéticamente modificados y la necesidad de regulación en los países. PMID:21927675

  10. Remaking the Guatemalan midwife: health care reform and midwifery training programs in Highland Guatemala.

    PubMed

    Maupin, Jonathan N

    2008-01-01

    Midwifery practice and identity in Guatemala is constantly being transformed because midwives must negotiate their practices in response to changing international and national health care agendas and processes. Recently, the Guatemalan government implemented the Sistema Integral de Atención en Salud (SIAS). Framed by neoliberal processes and global reproductive health paradigms, SIAS is designed to attain the reproductive health goals outlined in the 1996 Peace Accords by reducing maternal and infant mortality rates. As the primary birthing specialists in rural areas, midwives are essential to this task. A central focus of SIAS is incorporating midwives into the national health care system through midwifery training programs. Drawing on observations of midwifery training programs and interviews with midwives in the municipality of San Martín Jilotepeque, I argue that the incorporation of midwives into SIAS is redefining the position by establishing a new model of recruitment to the role, education, and practice and authority. PMID:18958785

  11. Captura de galaxias enanas en cúmulos de galaxias

    NASA Astrophysics Data System (ADS)

    Bassino, L. P.; Muzzio, J. C.; Pérez, J.

    Se investiga el proceso de captura de galaxias enanas por parte de galaxias gigantes, en presencia de un campo externo causado por materia distribuída y otras galaxias pertenecientes al cúmulo en que se produce el fenómeno. Se trabaja mediante simulaciones numéricas, generando condiciones iniciales típicas de cúmulos de galaxias y representando, con un espectro de masas, a las galaxias más masivas y, como partículas de prueba, a las enanas. Se sigue la evolución del sistema empleando un código de integración de N-cuerpos y se analizan los resultados para determinar las capturas de galaxias enanas.

  12. The Use of a Meteorological Station Network to Provide Crop Water Requirement Information for Irrigation Management

    NASA Astrophysics Data System (ADS)

    Carlesso, Reimar; Petry, Mirta Teresinha; Trois, Celio

    Despite of the water use increment for other sectors than agriculture, the water use for irrigation is the main water consumer in global scale. However, irrigation has been pressured by the civil society to improve water use efficiency in agriculture, to prevent water scarcity for human population that grows continuously, mainly in developing areas of the planet. On the other hand, the irrigation practice is considered the main tool to increase water use efficiency, either for increasing crop production or for keeping rural works in the agricultural areas. The water use efficiency can be improved through the adoption of an efficient irrigation management and programming that results in water conservation. Several methods of irrigation management have been developed and used in the last few decades, but the adoption of the majority of then by the irrigated grower was limited by the cost, time of installation, maintenance and local difficulties that the selection of a specific method involves. In arid regions, the decision of "when" and "how much" to irrigate is relatively simple. However, in wet regions when complementary irrigation is used, the irrigation scheduling is a complex task, mainly due to the water added from rainfall events. The Sistema Irriga™ is basically a service of irrigation management developed by the Federal University of Santa Maria, Brazil. The criteria used by this method to decide the amount of each irrigation application is based on crop parameters of the irrigated crop, soil physical characteristics, meteorological conditions and characteristics of the irrigation system and irrigation method, combined with a mathematical model to determine the reference and crop evapotranspiration. This paper describes all factors and parameters used by the Sistema Irriga™ service, since the data acquisition (plant, soil, weather and irrigation system information), data processing and how the irrigation recommendation is available to the farmers.

  13. The Use of a Meteorological Station Network to Provide Crop Water Requirement Information for Irrigation Management

    NASA Astrophysics Data System (ADS)

    Carlesso, Reimar; Petry, Mirta Teresinha; Trois, Celio

    Despite of the water use increment for other sectors than agriculture, the water use for irrigation is the main water consumer in global scale. However, irrigation has been pressured by the civil society to improve water use efficiency in agriculture, to prevent water scarcity for human population that grows continuously, mainly in developing areas of the planet. On the other hand, the irrigation practice is considered the main tool to increase water use efficiency, either for increasing crop production or for keeping rural works in the agricultural areas. The water use efficiency can be improved through the adoption of an efficient irrigation management and programming that results in water conservation. Several methods of irrigation management have been developed and used in the last few decades, but the adoption of the majority of then by the irrigated grower was limited by the cost, time of installation, maintenance and local difficulties that the selection of a specific method involves. In arid regions, the decision of “when” and “how much” to irrigate is relatively simple. However, in wet regions when complementary irrigation is used, the irrigation scheduling is a complex task, mainly due to the water added from rainfall events. The Sistema Irriga™ is basically a service of irrigation management developed by the Federal University of Santa Maria, Brazil. The criteria used by this method to decide the amount of each irrigation application is based on crop parameters of the irrigated crop, soil physical characteristics, meteorological conditions and characteristics of the irrigation system and irrigation method, combined with a mathematical model to determine the reference and crop evapotranspiration. This paper describes all factors and parameters used by the Sistema Irriga™ service, since the data acquisition (plant, soil, weather and irrigation system information), data processing and how the irrigation recommendation is available to the farmers.

  14. On telescópio remoto do Observatório Abrahão de Moraes - Obelix

    NASA Astrophysics Data System (ADS)

    Neres, N. L.; Raffaelli, J. C.; Medina Tanco, G. A.; Horvath, J. E.; Maluhy, R.; Martins, A.; Orselli, M. I. V.

    2003-08-01

    Foi desenvolvido um telescópio totalmente automático situado no Observatório Abrahão de Moraes, em Valinhos-SP, que possibilita observações remotas via Internet tanto para fins profissionais como didáticos. Usando um programa navegador da WWW, o observador tem acesso a páginas interativas que permitem não só apontar o telescópio e receber as imagens, como também controlar a abertura e o fechamento da cúpula, monitorar temperatura, umidade e orvalho e receber imagens das câmaras de segurança. O fechamento da cúpula é feito automaticamente em caso de perigo de condensação. O sistema consiste de uma câmara Apogee, uma roda de filtros SBIG modelo CFW-8 com filtros RGB e um telescópio Meade. A observação remota é feita usando programas comerciais da área. Uma caixa de controle com lógica programável controla o movimento da cúpula e a energização do telescópio. Um software em LabView adquire os dados da estação meteorológica, que inclui um sensor de chuva desenvolvido no IAG, e apresenta seus valores atuais e históricos. Usando uma facilidade do próprio LabView, a saída desse software é exportada para a Internet. Um programa em C disponibiliza as imagens das câmaras de segurança usando uma placa de captura de vídeo e um seqüencial de vídeo que foi adaptado para ser controlado pelo PC. O sistema completo já se encontra operacional.

  15. Excitação e fotoabsorção de moléculas interestelares no ultra violeta

    NASA Astrophysics Data System (ADS)

    Rodrigues, A. M. F.; Boechat-Roberty, H. M.; Souza, G. B.; Turci, C. C.

    2003-08-01

    O estudo dos processos de excitação, fotoabsorção e ionização molecular nas nuvens interestelar, permite a análise dos processos químicos, como a formação e destruição de moléculas, até mesmo daquelas que dão origem à vida. Acredita-se que as moléculas como CS2, NH3, CO2 e N2O estão presentes nas nuvens onde são formadas as estrelas e seus sistemas planetários. Estas moléculas são congeladas na superfície de objetos densos, como aqueles encontrados na Nuvem de Oort do nosso Sistema Solar. Quando esses objetos (cometas) desprendem-se dessa região, aproximam-se do Sol, sofrem a interação da radição Ultra Violeta (UV), passam à fase gasosa e são bombardeados por íons e elétrons presentes nos ventos solares. Obtivemos os espectros de fotoabsorção do CS2, NH3 e N2O na faixa do UV, convertendo espectros de Perda de Energia de Elétrons, medidos no menor ângulo de espalhamento e na energia de impacto de 1000 eV. Destes espectros determinamos os valores de força de oscilador (f) e de seção de choque absolutas na faixa de 500 a 2000 Å. Para tal, estudamos e comparamos dois diferentes métodos de conversão. Neste trabalho também geramos muitos dados moleculares como, valores absolutos de seção de choque elástica em função do ângulo de espalhamento e a distribuição de força do oscilador generalizada (df/dE) em função da energia de excitação para diversos ângulos de espalhamento. Comparando nossos espectros de fotoabsorção com o espectro da atmosfera de Júpiter, obtido pelo Telescópio Espacial Hubble, logo após o impacto do cometa Shoemaker-Levy 9, confirmamos a presença do CS2 e da amônia.

  16. La formación de la Nube de Oort y el entorno galáctico primitivo

    NASA Astrophysics Data System (ADS)

    Fernández, J. A.

    Se analizan las condiciones de formación de la nube de Oort en el medio galáctico primitivo, bajo la suposición de que los objetos que alcanzaron la nube fueron planetesimales residuales eyectados por los planetas gigantes durante las etapas finales de su acreción. Los objetos que adquieren órbitas cuasiparabólicas están sujetos a las perturbaciones de estrellas vecinas y al potencial del disco galáctico, las que desacoplan sus perihelios de la región planetaria, dando a los objetos una larga estabilidad dinámica. Se demuestra que un entorno galáctico como el presente pudo, sin embargo, no ser suficiente para formar un reservorio cometario con una vida dinámica comparable a la vida del sistema solar. La existencia de la nube de Oort después de 4600 millones de años es, pues, una fuerte indicación de que el sistema solar se formó en un entorno galáctico mucho mas denso que el presente, tal vez en una nube molecular y/o un cúmulo abierto, que es el modo de producción de la mayoría de las estrellas. Se encuentra que un campo perturbador externo mas intenso, producto de un entorno galáctico mas denso, sería capaz de formar una nube de Oort mas compacta, con un radio del orden de 103- 104 UA. El campo externo mas intenso cesó de actuar una vez que la nube molecular y/o el cúmulo abierto se disiparon, previniendo entonces que ese mismo campo externo disolviera el reservorio cometario.

  17. Recherche et Analyse de Galaxies Brilliantes EN Exces EN Ultraviolet

    NASA Astrophysics Data System (ADS)

    Coziol, Roger

    Dans ce travail, nous decrivons et presentons les resultats du sondage Montreal Blue Galaxy (MBG) visant la recherche de galaxies emettant en exces en ultraviolet. Cette recherche utilise le materiel photographique du sondage MCT (Montreal-Cambridge-Tololo) qui par son etendue correspond a un des plus importants sondages de l'hemisphere austral. Le sondage MBG est presentement le seul dans cet hemisphere a employer la technique de poses multiples pour la selection de ses candidats. Grace a cette technique, nous avons l'occasion d'etudier un echantillon de galaxies ayant des caracteristiques quelque peu differentes de celles des echantillons analyses auparavant. Deux phenomenes peuvent expliquer l'exces d'ultraviolet observe dans ces galaxies. Le premier suppose la presence dans leur noyau d'un trou noir massif. Toutes les galaxies sujettes a ce type d'activite sont regroupees sous le nom de galaxies avec noyau actif (AGN). Le deuxieme phenomene est relie a une periode de formation intense d'etoiles, ou sursaut de formation d'etoiles ("starburst"). L'exces d'ultraviolet trahit ici la presence d'un grand nombre d'etoiles massives recemment creees au sein de ces galaxies. En plus d'augmenter le nombre d'AGN connues, les sondages de galaxies brillantes en ultraviolet permettent aussi d'approfondir les questions specifiques suivantes: combien y a-t'il de galaxies starbursts differentes? Quelle est l'origine possible de leur activite? Quel est le role des sursauts de formation d'etoiles dans la vie d'une galaxie? Quel est le lien entre les galaxies starbursts et les AGN?. L'analyse de notre echantillon de galaxies se fait par l'entremise de plusieurs methodes. La premiere consiste a obtenir des spectres optiques de nos candidats. L'etude de ces spectres nous permet de distinguer entre les AGN et les galaxies starbursts et de deduire plusieurs parametres physiques importants. Notre deuxieme methode consiste a obtenir des images. Ceci nous permet d'avoir une idee de la morphologie des galaxies et ainsi de comprendre ies phenomenes sous-jacents aux sursauts de formation d'etoiles. En plus de la forme et des dimensions, une analyse des images prises sous differents filtres nous permet d'etudier les differentes populations stellaires presentes et d'en comprendre l'evolution. La troisieme methode employee pour notre etude utilise les informations en infrarouge du satellite americain IRAS. Ces donnees nous renseignent sur la quantite et l'etat de la poussiere associee a l'activite de ces galaxies. Les resultats faisant l'objet de cette these portent sur 40% du sondage total. L'echantillon etudie compte 332 galaxies, dont 60 ont ete observees en spectroscopie et 15 analysees en imagerie. Les AGN ne constituent que 5% des galaxies de notre echantillon. La majorite de nos candidats sont des galaxies starbursts. Leur caracteristique principale est que le sursaut de formation d'etoiles est principalement localise dans la region de leur noyau. La majorite des galaxies starbursts de notre echantillon ont une morphologie de type spirale precoce et contiennent des populations stellaires relativement evoluees. Plusieurs indices suggerent que les sursauts de formation detoiles sont relies a une accretion relativement recente de matiere provenant soit de leur environnement soit de l'interaction avec d'autres galaxies. Les sursauts de formation d'etoiles peuvent etre de longue duree (de l'ordre de 10 ^9 annees) ou peuvent se produire en cascades. Ces resultats semblent typiques des galaxies avec sursauts de formation d'etoiles dans le noyau. L'importance du phenomene laisse penser qu'il s'agit d'une phase majeure dans l'evolution de ces galaxies.

  18. Etude des facteurs liés à l'observance au traitement antirétroviral chez les patients suivis à l'Unité de Prise En Charge du VIH/SIDA de l'Hôpital de District de Dschang, Cameroun

    PubMed Central

    Mbopi-Kéou, François-Xavier; Dempouo Djomassi, Lucienne; Monebenimp, Francisca

    2012-01-01

    Introduction Etudier les facteurs liés à l'observance au traitement antirétroviral chez les patients adultes suivis à l'Unité de Prise en Charge du VIH/SIDA (UPEC) de l'hôpital de District de Dschang. Méthodes Dans une étude descriptive transversale conduite à l'hôpital de District de Dschang, l'observance a été évaluée sur la base des déclarations des patients et sur la régularité du renouvellement de leurs ordonnances (observance calculée). Résultats Parmi les 389 patients répondant à nos critères d'inclusion, 356 ont été interrogés. La durée moyenne du suivi était de 27 mois. La moyenne d’âge était égale à 41 ans et le sexe ratio 2,46 en faveur du sexe féminin. Le statut sérologique était découvert pour 60,56% des patients à l'occasion d'un épisode maladif. Le niveau d'observance déclarée était significativement plus élevé que le niveau global de l'observance calculée (80,2% vs 51,5%, p<10−5). Les deux principales barrières à l'observance étaient l'oubli et le travail. Les patients référés dans cette UPEC étaient moins bien observants (p<10−4). L'observance au traitement antirétroviral était d'autant meilleure quand le taux de CD4 en début de traitement était élevé (p= 0,01) et que la durée du traitement était prolongée (p=0,00). Conclusion La discordance observée entre les résultats des deux méthodes utilisées pour estimer l'observance, tout en soulévant les contraintes liées à l’évaluation de l'observance thérapeutique, souligne l'importance des méthodes biologiques. Les facteurs individuels se sont avérés être les principales raisons de non-observance. Enfin, un accent devrait être mis sur les consultations d’éducation thérapeutique et le suivi psycho-social des patients sous traitement antirétroviral dans cette UPEC. PMID:22937195

  19. Aspects cliniques et biologiques des anémies pédiatriques dans un hôpital de District urbain au Cameroun

    PubMed Central

    Koum, Danièle Kedy; Tsakeu, Eveline Ngouadjeu Dongho; Sack, Françoise Ngo; Ngalagou, Pierre Tchienrg Moueleu; Kamanyi, Albert; Mandengue, Samuel Honoré

    2013-01-01

    Introduction L'anémie est un problème de santé publique prédominant chez les enfants et les femmes en âge de procréer. L'objectif de cette étude était de caractériser et de déterminer sa prévalence chez les enfants âgés de 6 mois à 14 ans hospitalisés à l'hôpital de District de Bonassama à Douala-Cameroun. Méthodes Il s'agissait d'une étude descriptive transversale qui s'est déroulée de février à mars 2012 avec une collecte rétrospective des données de janvier 2009 à mars 2012. Etaient inclus, les patients de 6 mois à 14 ans hospitalisés, quel que soit leur motif de consultation et leur diagnostic, et ayant réalisé au moins une numération formule sanguine (NFS). Les patients transfusés moins de 120 jours avant la NFS étaient exclus. L’âge, le sexe, les motifs de consultation, les signes cliniques, les diagnostics et les résultats de la NFS étaient enregistrés. L'anémie était définie selon les critères de l'OMS. La recherche étiologique était guidée par les signes cliniques et les examens complémentaires. Résultats La prévalence de l'anémie était de 88,5%. Le sex-ratio garçon/fille était de 1,3. La fièvre était le premier motif de consultation. L'anémie modérée prédominait (62,7%). Le taux moyen d'hémoglobine chez les patients anémiques était de 8,6 ± 1,7 g/dl (2,3- 11,4). L'anémie microcytaire hypochrome dominait (48,5%). Le paludisme était la principale pathologie (46,3%). Le taux de mortalité des patients anémiques était de 5,9%. Conclusion La prévalence de l'anémie était élevée avec une prédominance des formes hypochromes microcytaires. La principale étiologie était le paludisme. PMID:24772220

  20. Les Elements Legers: Diffusion dans les Enveloppes Stellaires et Implications Cosmologiques

    NASA Astrophysics Data System (ADS)

    Richer, Jacques

    1992-01-01

    Les observations des abondances des elements legers (Z <= 5) sont utilisees pour estimer la quantitie de lithium qui a ete produite lors du Big -Bang, et obtenir simultanement des contraintes sur la nature des inhomogeneites qui ont pu exister durant la nucleosynthese primordiale. Nous utilisons un modele simple capable de simuler approximativement la diffusion et la retro-diffusion des neutrons a travers la matiere inhomogene durant les premieres minutes de l'expansion de l'Univers. Nous tenons compte de la difference possible entre l'abondance primordiale de Li et les abondances observees dans les plus vieilles etoiles. Cette difference (un facteur 2, environ) est estimee en construisant des modeles evolutifs d'etoiles peu massives de Population II, incluant la sedimentation gravitationnelle du lithium et de l'helium. Ces modeles montrent egalement que les ages des vieux amas stellaires sont grandement surestimes lorsqu'ils sont determines a partir de modeles stellaires n'incluant pas l'effet de la diffusion de He. Nous calculons ensuite comment evoluent les abondances de Li et Be dans des etoiles plus massives et plus jeunes, de la pre-sequence principale ou de la ZAMS, jusqu'a l'epuisement de leur hydrogene central. Les modeles incluent la sedimentation simultanee de l'helium a travers l'enveloppe. Une approche hierarchique (evolution du coeur--evolution de l'enveloppe --tri des elements traces) est utilisee pour simuler efficacement le grand nombre d'etoiles necessaire pour la construction d'isochrones. Une attention particuliere est portee aux consequences de la sedimentation de He sur l'etendue des zones convectives, et sur la diffusion de Li et Be. Les forces radiatives agissant sur ces deux elements sont calculees en detail a partir des donnees atomiques. Les etoiles simulees correspondent approximativement aux types spectraux A, F, et AmFm. Les abondances de Li et Be observees dans les etoiles jeunes de ces types sont comparees a nos predictions dans le but d'identifier les conditions ou la diffusion peut etre le processus principal. ou un processus important controlant les abondances superficielles observees. La position et la profondeur du "trou du lithium" observe parmi les etoiles F des Hyades et d'autres amas jeunes, sont reproduites sans l'aide de parametres ajustables; cet accord n'est obtenu que si les recentes opacites OPAL sont employees. La largeur de "trou" observee est cependant environ le double de la largeur calculee. Certaines observations (parmi les etoiles les plus chaudes) ne peuvent pas etre expliquees uniquement par l'action du tri gravitationnel et des forces radiatives; nous discutons les principales alternative proposees par d'autres auteurs. Nous montrons a l'aide d'autres modeles evolutifs detailles que les vents stellaires (la perte de masse) pourraient reconcilier theorie de la diffusion et observations, sous certaines conditions. L'existence du "trou du lithium" dans les Hyades implique des contraintes severes sur les taux de perte de masse possibles. Le meme accord partiel est obtenu entre les observations du beryllium et nos modeles, mais la qualite et le nombre de mesures d'abondances de Be disponibles ne permettent pas une analyse aussi poussee des resultats pour cet element.