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Sample records for percibida ante dilemas

  1. DILEMAS MORALES

    Directory of Open Access Journals (Sweden)

    Sandra Realpe Quintero

    2001-01-01

    Full Text Available Antes del siglo XX la tradición filosófica moral ha reconocido la existencia de los conflictos morales pero ha rechazado la posibilidad de los auténticos dilemas morales. Para poder entender por qué hoy el tema de los dilemas morales ha reclamado para sí tanta atención, es importante ponernos de acuerdo en la definición de algunos conceptos. Un conflicto moral es una situación en la que un(a agente se ve confrontado(a con dos obligaciones morales que le instan a actuar. Un dilema moral es una situación extrema de conflicto moral en la que nuestro(a agente no puede seguir un curso de acción que sea conforme con sus dos obligaciones en conflicto. Para que un conflicto moral tenga el carácter de ser un auténtico dilema moral (genuine moral dilemma y no simplemente un aparente dilema moral (apparent moral di- DILEMAS MORALES SANDRA REALPE Licenciada en Filosofía, Univalle, Maestría en Filosofía, Univalle, Diplomado en Psicología Aplicada, Universidad de Londres, Diplomado en Etica de los Negocios Universidad de Colorado, profesora Universidad Icesi, Facultad de Derecho y Humanidades. E-mail: sandrarealpe@hotmail.com lemma, ninguna de las obligaciones en conflicto es en efecto más fuerte o logra invalidar a la otra obligación. A raíz de un artículo escrito en 1962 por E. J. Lemmon, titulado precisamente “Dilemas morales” (Moral Dilemmas, se abrió un debate entre los filósofos anglosajones contemporáneos acerca de la existencia o no de los auténticos dilemas morales. Informar sobre este debate reciente, esclarecer los argumentos de sus principales protagonistas, y hacer presente en nuestro medio un novedoso debate que es importante para reflexionar sobre un buen número de problemas morales, son nuestros principales propósitos en el presente ensayo. ...

  2. La aplicación jurídica ante algunos dilemas semánticos de Luigi Ferrajoli || The Legal Adjudication Faced With Some Semantic Dilemmas of Luigi Ferrajoli

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    Roberto Marino Jiménez Cano

    2012-12-01

    Full Text Available Resumen: A juicio de Luigi Ferrajoli los textos constitucionales incorporan condiciones sustanciales de validez, que se refieren a valores como como la libertad, la igualdad o las garantías de los derechos de los ciudadanos. Por otra parte, el significado del lenguaje jurídico, el de los juristas y el de los jueces, se expresa a través de definiciones lexicográficas  que toman como base observacional los usos del legislador. Este trabajo plantea las diferentes alternativas y dilemas ante los que se presenta Ferrajoli a la hora de explicar la posibilidad de que los jueces realicen enunciados operativos cuando el lenguaje legal o constitucional es vago o contiene condiciones sustanciales de validez.   Abstract: According to Luigi Ferrajoli constitutional texts incorporate substantial conditions of validity, which refer to values ??such as freedom, equality and guarantees of rights. On the other hand, the meaning of legal language, the language of lawyers and judges, is expressed through lexical definitions based on the observational uses of the Legislature. This paper discusses the various alternatives and dilemmas for Ferrajoli to explaining the possibility that judges make operatives statements when the legal or constitutional language is vague or when it contains substantial conditions of validity.

  3. La aplicación jurídica ante algunos dilemas semánticos de Luigi Ferrajoli || The Legal Adjudication Faced With Some Semantic Dilemmas of Luigi Ferrajoli

    Directory of Open Access Journals (Sweden)

    Roberto Marino Jiménez Cano

    2012-12-01

    Full Text Available Resumen:A juicio de Luigi Ferrajoli los textos constitucionales incorporan condiciones sustanciales de validez, que se refieren a valores como como la libertad, la igualdad o las garantías de los derechos de los ciudadanos. Por otra parte, el significado del lenguaje jurídico, el de los juristas y el de los jueces, se expresa a través de definiciones lexicográficas  que toman como base observacional los usos del legislador. Este trabajo plantea las diferentes alternativas y dilemas ante los que se presenta Ferrajoli a la hora de explicar la posibilidad de que los jueces realicen enunciados operativos cuando el lenguaje legal o constitucional es vago o contiene condiciones sustanciales de validez. Abstract: According to Luigi Ferrajoli constitutional texts incorporate substantial conditions of validity, which refer to values ??such as freedom, equality and guarantees of rights. On the other hand, the meaning of legal language, the language of lawyers and judges, is expressed through lexical definitions based on the observational uses of the Legislature. This paper discusses the various alternatives and dilemmas for Ferrajoli to explaining the possibility that judges make operatives statements when the legal or constitutional language is vague or when it contains substantial conditions of validity. 

  4. ANT

    DEFF Research Database (Denmark)

    van der Duim, René; Ren, Carina Bregnholm; Jóhannesson, Gunnar Thór

    2017-01-01

    Ten years ago actor-network theory (ANT) entered this journal. To illustrate how the relational ontology and sensibilities of ANT lend themselves to particular kinds of research, we first interrogate the main controversies as a way to open up and discuss the main premises of ANT. These debates...... concern the status and agency of objects and non-humans, ANT’s denial of the explanatory power of social structures, and the political implications of ANT. Second we present ANT’s relevance for tourism studies and discuss what ANT ‘does’ in practice. After summarizing a decade of relations between ANT...... and tourism, we conclude by tracing three future trajectories of how we have ‘moved away with’ ANT into new areas of discovery....

  5. dilemas morais?

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    Pedro Merlussi

    2013-12-01

    Full Text Available http://dx.doi.org/10.5007/1677-2954.2013v12n2p207 O problema deste ensaio é o de saber se há dilemas morais. Defendo que é plausível pensar que não. Há, no entanto, diversos argumentos contra essa tese. Na primeira parte deste ensaio, formulo e discuto um dos argumentos mais influentes: o argumento fenomenológico. Depois disso, mostrarei que, caso aceitemos alguns princípios plausíveis, teremos de recusar a existência de dilemas morais. Mas essa conclusão é prima facie implausível: intuitivamente parece haver dilemas morais genuínos. A última etapa deste ensaio é uma tentativa de explicar por que esta intuição é uma ilusão. Argumentarei que nossas intuições atestam que se trata de um caso no qual não sabemos o que fazer (em virtude de nossa limitação cognitiva, mas não que seja um conflito genuíno de obrigações.

  6. EL CIRCO Y MI DILEMA

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    Martalucía Tamayo

    2015-03-01

    Full Text Available La presente es para solicitar la publicación en la revista MEDICINA de la Academia, la siguiente carta abierta que le envié al Fundador y Director Ejecutivo del Cirque du Soleil, Sr. Guy Laliberté, en relación con la presentación en su espectáculo de pacientes que padecen enfermedades de tipo genético. Apreciado amigo: Con todo respeto me permito llamarlo amigo, ante la simpatía que me producen muchos aspectos de su vida pública. Pero aclaro que necesito expresar esto, porque cada vez que veo una función del Circo del Sol, no puedo evitar cuestionarme varias cosas con respecto al espectáculo que allí se presenta y me surge cada vez un cuestionamiento que me produce un gran dilema. Necesito expresarlo y abrir un conversatorio público que me ayude (a mí y a toda la sociedad a pensar y a entender. Estuve en el Circo del Sol en el actual espectáculo que se presenta en Bogotá (Marzo 20, 2015 y no pude evitar tener sentimientos encontrados. Allí encontré dos personas en el elenco de “artistas” que parecen tener una enfermedad genética que probablemente sea un Síndrome de Seckel (mal llamado “Enanismo en Cabeza de Pájaro» y no supe cómo interpretar su presencia en el circo: Me inquieta pensar que estén allí sólo para ser exhibidos como “seres raros” y me asalta el temor de que estemos retrocediendo en el tiempo: ¿Será que volvimos a la Edad Media, cuando los defectos físicos o las enfermedades genéticas eran dignas de exhibición, show y risa?. Recuerdo que hace varios años cuando fui a Nueva York y por primera vez vi el Circo del Sol (el mismo show que trajeron a Colombia hace unos 3 o 4 años, me sorprendió ver entre los espectáculos que allí mostraban, a una persona que probablemente tenía una enfermedad genética llamada el Síndrome de Ehlers-Danlos, patología que suele dar una enorme flexibilidad al cuerpo y le permite a la persona doblarse tanto como para ser capaz de caber o meterse dentro de una

  7. EMPRESAS DE CLASE Y CALIDAD PERCIBIDA

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    José Alfonso Macías Mesa

    2002-07-01

    Full Text Available

    Muchos autores hacen énfasis en la necesidad de redefinir los términos de excelencia empresarial. En este intento los momentos claves han sido marcados: la contabilidad de partida doble, las ventas y utilidades eran buenas medidas de efectividad; el control de inventario y la calidad total en las etapas más recientes. En la actualidad, la excelencia en términos de competencia está en la capacidad y el desempeño basado en información, centrado en el cliente y ejecutado por los empleados. El estudio de la calidad percibida, como medida que permite conocer la imagen que los clientes tienen sobre productos, servicios o empresas, es un proceder que se relaciona con el diseño de estrategias competitivas para marcar ventajas que permitan el tránsito hacia estándares de clase de las empresas. En el trabajo se analiza cómo se relacionan los conceptos calidad percibida y empresa de clase mundial, se sugiere una manera de medirla y se presenta un ejemplo práctico.

  8. Adaptación a la población española de un instrumento de juicios morales: la batería de dilemas morales de Moore

    Directory of Open Access Journals (Sweden)

    Martina Carmona-Perera

    2013-10-01

    Full Text Available Los procesos neuropsicológicos subyacentes al juicio moral son objeto de novedosas investigaciones en el ámbito de la cognición social. El objetivo de este estudio es adaptar a la población española la batería de dilemas morales de Moore. Esta batería plantea una serie de dilemas morales entre una elección utilitarista (asumir una conducta emocionalmente aversiva en favor de un beneficio mayor y otra no-utilitarista. Participaron 154 estudiantes universitarios que completaron la versión española del instrumento. Investigamos tres tipos de dilemas: morales-personales (el propio sujeto realiza la acción aversiva, incrementando la carga emocional, morales-impersonales (la acción es indirecta, reduciendo la carga emocional, y no-morales. Las variables dependientes fueron: la proporción de respuestas afirmativas -que refleja elecciones utilitaristas, y la dificultad percibida para llevar a cabo el juicio. Los resultados mostraron buenas propiedades psicométricas y validez discriminativa en función del tipo de dilema; los dilemas morales-personales generaron menor número de elecciones utilitaristas y juicios de mayor dificultad. En conclusión, la adaptación española del cuestionario permite medir de manera fiable el juicio moral, discriminando distintos patrones de elección en función de la carga emocional, postulándose como un instrumento potencialmente útil en la evaluación de poblaciones con problemas de toma de decisiones sociales y afectivas.

  9. A vida pessoal de trabalhadoras do sexo: dilemas de mulheres de classes populares

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    Marina França

    Full Text Available Resumo O artigo considera como mulheres prostitutas articulam suas relações afetivo-sexuais, condições econômicas e vida profissional. Observando suas experiências e seus relatos de relações com parceiros pessoais, antes e depois do início da prostituição, trata de aproximar a vida e os dilemas de trabalhadoras do sexo dos de outras mulheres, especialmente brasileiras de classes populares. Ao fazê-lo, aborda questões como gênero, maternidade, conjugalidade e suas tensões. Além disso, considera as especificidades de relacionamentos íntimos colocadas pela prostituição, e situações de envolvimento amoroso entre prostitutas e clientes. Atravessando os diversos temas, aparecem conexões entre afetos, sexualidade, dinheiro e trabalho.

  10. Calidad percibida en intercambiadores de transporte en Madrid

    OpenAIRE

    Dell Asin, Giulia; Monzón de Cáceres, Andrés

    2010-01-01

    En la última década, la intermodalidad de pasajeros ha sido uno de los elementos clave en la Política Común de la Unión Europea para facilitar el cambio modal, así como disminuir la congestión y la contaminación medio-ambiental en las ciudades europeas. En este contexto, los intercambiadores de transporte, los lugares donde se produce el intercambio entre modos de transporte, juegan un papel relevante. En el presente estudio, se ha analizado la calidad percibida por los usuarios larga-corta d...

  11. El dilema del arte popular en Bolivia

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    Lupe Cajas

    2015-01-01

    Full Text Available Aborda la comunicación desde las tres interpretaciones más importantes: la tradicionalista, la militar y mercantilista y el arte popular tan inestable, cuestionado y cambiante. Canclini cuestiona la compartamentalización de cultura: popular y de medios y esboza los problemas que plantea la tradicional miopía de no reconocer la universalización y ubicuidad de la cultura de masas. Se agregan otros temas como: ¿Re-intelección de los medios? apuntes sobre un libro de los Mattelart, ¿"Ética" o "Deontología" de la comunicación social?, El lenguaje del vestido y de la fiesta,Talleres de cultura Popular en Santiago de Chile, El dilema del arte popular en Bolivia,¿Sobrevivirán las artesanías aborígenes argentinas?, Los tejedores de El Tintorero, Tecnologías de computación y Tercer Mundo, La cobertura del terremoto en México, La comunicación como quehacer y como problema, la comunicación planificada sirve al desarrollo

  12. Inteligencia emocional percibida y optimismo disposicional en estudiantes universitarios

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    Óscar ANADÓN REVUELTA

    2006-01-01

    Full Text Available En la presente investigación se analizan las relaciones entre inteligencia emocional percibida (IEP y el optimismo disposicional, en una muestra de alumnos (N=102 de segundo curso de Magisterio (especialidades de Educación Primaria y de Lengua Extranjera: Inglés de la Facultad de Educación de Zaragoza. Se utilizaron los siguientes instrumentos: la Trait Meta-Mood Scale (TMMS, para evaluar la IEP, y el Life Orientation Test (LOT-R, para medir el optimismo disposicional. Los resultados muestran una moderada intercorrelación entre el subfactor de reparación de la IE y el optimismo disposicional. Ello sugiere que las personas con mayor capacidad para reparar sus estados emocionales negativos poseen expectativas generalizadas más favorables acerca de las cosas que les suceden en la vida.

  13. Síntomas de estrés postraumático en adolescentes expuestos a un terremoto: asociación con autoeficacia, magnitud percibida y miedo

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    Cristóbal Guerra

    2014-01-01

    Full Text Available El objetivo de este estudio fue evaluar la relación entre la magnitud percibida, el miedo experimentado, las creencias de autoeficacia y los síntomas de estrés post-traumático en adolescentes. Se esperaba que las creencias de autoeficacia se asociaran con los síntomas de estrés post-traumático y que esta relación fuera mediada por el miedo. Se utilizaron datos que formaban parte de un estudio longitudinal sobre desarrollo normativo en la adolescencia que estaba en curso al momento de ocurrir el terremoto del año 2010 en Chile. Seis meses antes del terremoto, 218 adolescentes respondieron una escala de creencias de autoeficacia y tres meses después del terremoto reportaron la magnitud percibida del terremoto, el miedo experimentado y los síntomas de estrés post-traumático. La magnitud percibida no se asoció al miedo ni a los síntomas de estrés post-traumático, pero las creencias de autoeficacia y el miedo se asociaron con los síntomas de estrés post-traumático. Se apoyó el rol mediador del miedo en la relación entre las creencias de autoeficacia y los síntomas de estrés post-traumático. Estos resultados preliminares sugieren que la prevención orientada a preparar a los adolescentes para enfrentar desastres naturales puede, además de salvar vidas, mejorar la respuesta emocional de aquellos que sobreviven.

  14. MODEL PEMBELAJARAN DILEMA MORAL DAN KONTEMPLASI DENGAN STRATEGI KOOPERATIF

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    C. Asri Budiningsih

    2013-09-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui keefektifan model Pembelajaran Dilema Moral, Kontemplasi, dan Strategi Kooperatif. Penelitian tindakan kelas dilakukan di Prodi Teknologi Pendidikan FIP-UNY. Subjek penelitian 37 orang mahasiswa. Tindakan dilakukan dalam dua siklus masing-masing terdiri atas empat kali tatap muka. Data tentang proses pembelajaran, kerjasama mahasiswa, situasi yang berpengaruh terhadap upaya peningkatan kualitas pembelajaran, penalaran moral, dan keimanan mahasiswa, digali melalui pengamatan, tes penalaran moral yang diadaptasi dari Kohlberg, tes perkembangan iman yang diadaptasi dari Fowler, panduan kontemplasi, angket terbuka, dan cerita-cerita dilema moral. Analisis data dilakukan secara kuantitatif dan kualitatif. Hasil penelitian menunjukkan bahwa (1 model pembelajaran terintegrasi mampu meningkatkan penalaran moral, dan keimanan mahasiswa, sehingga tidak ada lagi penalaran moral responden yang berada pada tahap II, 24,3% meningkat dari tahap II ke tahap III, 32,43% meningkat dari tahap III ke tahap IV dan 2,7% meningkat dari tahap IV ke tahap V, 48,65% meningkat dari tahap III ke tahap IV, dan 5,4% meningkat dari tahap IV ke tahap V. Penggunaan strategi kooperatif membuat mahasiswa mampu melakukan kerjasama di dalam kelompok; 35,13% mahasiswa dalam kategori sangat baik, 56,76% dalam kategori baik, dan 8,1% dalam kategori sedang. Kata kunci       :           model pembelajaran dilema moral, kontemplasi, strategi kooperatif, penalaran moral, keimanan

  15. Militares y democracia. ¿El dilema de la Venezuela de principios del siglo XXI?

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    Irwin G., Domingo

    2004-08-01

    Full Text Available After an historiographical review, this article seeks to shed light on a somewhat forgotten question of the Venezuelan recent history: the civil-military relations in the context of the peculiar symbiosis that stretched from the fall of the Dictatorship in 1958 through the 1992 crisis, as well as the dilemma that nowadays confronts a military sector that is protagonizing the political debate due to the radicalization of Hugo Chávez’s Bolivarian Revolution.

    Partiendo de un balance historiográfico, este estudio intenta aclarar un aspecto algo olvidado de la historia reciente de Venezuela: las relaciones civiles-militares, desde la peculiar simbiosis que se da desde la caída de la dictadura en 1958 hasta la crisis de 1992 y el dilema que enfrenta, hoy en día, un sector militar convertido en protagonista del debate político ante la radicalización de la Revolución Bolivariana del Presidente Hugo Chávez.

  16. El dilema del prisionero en la teoría de juegos

    OpenAIRE

    Rayo Trigueros, Rodrigo

    2016-01-01

    En el trabajo fin de grado con título “el dilema del prisionero en la teoría de juegos” se analiza principalmente el propio dilema del prisionero, siendo uno de los más conocidos dentro de la teoría de juegos. Se pretende situar el dilema dentro de la teoría de juegos para poder entenderlo de una forma más clara. Está presente también el equilibrio de nash, ya que guarda una relación directa con el dilema del prisionero. Se incluyen los juegos repetidos puesto que el dilema del prisionero pue...

  17. Los determinantes de la salud percibida en España

    OpenAIRE

    Girón Daviña , Pedro

    2010-01-01

    Esta tesis plantea como hipótesis de trabajo que la salud percibida en España es un indicador multidimensional e integral de la salud que está vinculado a los factores que afectan a la salud objetiva, lo que le convierte en un indicador complementario a otras medidas de salud de los profesionales sanitarios. El objetivo de esta tesis es analizar y modelar los distintos determinantes de la salud percibida de los españoles de 16 o más años de edad. Para ello se utiliza la ENS del año 2006, ...

  18. El periodista, ante la espiral de silencio

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    Dr. Fermín Galindo Arranz

    1998-01-01

    Full Text Available La percepción de la profesión periodística y de su influencia cambia mucho a lo largo del tiempo, de las coyunturas históricas y de los diferentes países y sociedades en los que desempeñan su labor. En un contexto mundial, la gravedad de las situaciones de riesgo periodístico se encuadran en situaciones políticas, económicas o sociales también conflictivas; es entonces cuando se suele reproducir con facilidad en la opinión pública el fenómeno de la espiral del silencio, ante el que inevitablemente se sitúa el periodista. Por definición, el trabajo del periodista consiste en ser portavoz de las novedades que se producen, en dar informaciones y emitir opiniones en la esfera pública, se tiene que situar, por tanto, de forma individual y notoriamente pública ante los fenómenos de espiral de silencio que puedan producirse en la opinión pública. Antonio Tabucchi nos presenta en su novela "Sostiene Pereira" un ejemplo magnífico del dilema del periodista ante este tipo de situaciones.

  19. Beyond ANT

    DEFF Research Database (Denmark)

    Jansen, Till

    2017-01-01

    Actor-Network-Theory (ANT) offers an ‘infra-language’ of the social that allows one to trace social relations very dynamically, while at the same time dissolving human agency, thus providing a flat and de-centred way into sociology. However, ANT struggles with its theoretical design that may lead...... us to reduce agency to causation and to conceptualize actor-networks as homogeneous ontologies of force. This article proposes to regard ANT’s inability to conceptualize reflexivity and the interrelatedness of different ontologies as the fundamental problem of the theory. Drawing on Günther......, it offers an ‘infra-language’ of reflexive relations while maintaining ANT’s de-centred approach. This would enable us to conceptualize actor-networks as non-homogeneous, dynamic and connecting different societal rationales while maintaining the main strengths of ANT....

  20. América Latina ante un histórico dilema: unidos o dominados

    OpenAIRE

    Morgenfeld, Leandro Ariel

    2017-01-01

    Desde las mismas guerras de independencia latinoamericanas, se comenzaron a debatir diferentes alternativas de unidad o integración de los países del sur del continente. A lo largo de la historia, y producto tanto de las presiones de Estados Unidos y las potencias europeas por un lado, como del carácter de las clases dominantes de los países del continente por el otro, la fragmentación siempre se impuso a los proyectos latinoamericanistas. En las últimas dos décadas, los principales debates s...

  1. A esquerda europeia ante os dilemas da imigração

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    André Freire

    2009-01-01

    Full Text Available In spite of the thesis about the “end of ideology”, about the “end of history”, or about a certain overcome of the division between left and right, the truth is that these same theses have an ideological dimension and, little time after their formulation, they were followed by the emergence of new ideological forms or by the leading relevance of “old” ideologies. Additionally, several studies have been documenting the growing importance of the voters’ position in the left-right scale as an explicative factor of their vote option. In the present article, we analyse (in time and space the different perspectives and meanings associated to the division between left and right in Europe, as well as the correlates of the division between left and right in terms of cleavages, speci?cally in terms of the so called “old” and “new politics”, or, to put it differently, in terms of the so called “new” and “old” cleavages. Having in mind the precedent contextualization, the last three sections of the article give an approach to the dilemmas of the European left when facing immigration

  2. Apostando na Continuidade? O Eleitor Brasileiro ante os Dilemas do Governo Lula

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    Christiane Ströh

    2014-06-01

    Full Text Available Diante dos recentes escândalos no cenário político brasileiro, motivados pela descoberta dos esquemas de corrupção para a construção de maiorias parlamentares através da compra de votos para o atual governo, as crescentes intenções de voto em Lula podem parecer estranhas – ou até mesmo pouco éticas.

  3. Bienestar psicológico, salud general, autonomía percibida y lesiones en futbolistas

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    Claudia Rivas

    2012-01-01

    Full Text Available Dada la preocupación por la práctica deportiva de forma saludable, el objetivo de este estudio es estudiar el nivel de bienestar psicológico eudaimónico (Ryff, 1989a y de salud general y emocional, y de averiguar su relación con la autonomía percibida y sus historiales de lesiones deportivas en una población de 85 futbolistas de competición de México. Se ha utilizado la Escala de Bienestar Psicológico, (EBP, Díaz et al., 2006; la Escala de Autonomía Percibida en el Deporte (Balaguer, Castillo y Duda, 2008; la versión española (Sánchez y Dresch, 2008 del 12-item General Health Questionnaire (GHQ-12, Goldberg y Hillier, 1979, y sus historiales de lesiones (antecedentes y consecuentes se evaluaron mediante un cuestionario ad hoc derivado del Modelo Global Psicológico de Lesiones Deportivas (Olmedilla y Garcia-Mas, 2009. Los resultados muestran que los futbolistas tienen una mala percepción de salud general y emocional, pero poseen buenos niveles de bienestar psicológico en relación con la autonomía percibida. El número de lesiones -no su duración- se relaciona con la mala percepción de salud general y emocional a la vez que lo hace negativamente con el aspecto volitivo de la autonomía percibida. Los futbolista percibensus lesiones relacionadas con antecedentes psicológicos de estrés y ansiedad competitiva.

  4. Fire Ant Bites

    Science.gov (United States)

    ... Favorite Name: Category: Share: Yes No, Keep Private Fire Ant Bites Share | Fire ants are aggressive, venomous insects that have pinching ... across the United States, even into Puerto Rico. Fire ant stings usually occur on the feet or ...

  5. Calidad percibida por dos poblaciones adscritas a dos centros de salud de la provincia de Cuenca

    Directory of Open Access Journals (Sweden)

    Retamal González Antonio

    2000-01-01

    Full Text Available FUNDAMENTO: Para prestar un servicio de calidad es fundamental conocer la opinión que sobre la misma tienen los usuarios del mismo. El objetivo del presente trabajo es medir y comparar la calidad percibida por dos poblaciones asignadas a dos centros de salud de la provincia de Cuenca. MÉTODO: Se trata de un estudio descriptivo transversal. Las Zonas Básicas de Salud estudiadas han sido el Centro de Salud de Cardenete y Centro de Salud de Motilla del Palancar, ambos del Área de Salud de Cuenca. Se ha hecho un muestreo aleatorio estratificado por cuotas de edad y sexo a partir de la tarjeta sanitaria individual. Se ha medido la calidad percibida con un cuestionario validado y fiable, utilizado anteriormente con fines similares por el Ministerio de Sanidad y Consumo. RESULTADOS: Se analizan un total de 295 encuestas, 147 a varones y 148 a mujeres. La media de edad es de 48,83 años (DE: 18,77 para el Centro de Salud de Motilla, en Centro de Salud de Cardenete es de 61,93 años (DE: 15,17. La media de frecuencias mensuales de visitas para Centro de Salud de MP ha sido de 1,56 (DE: 1,91; esta media para el Centro de Salud de Cardenete ha sido:2,49 (DE: 4,27. La media de frecuencias semanales para el Centro de Salud de MP ha sido: 0,32 (DE: 0,66; para el Centro de Salud de Cardenete ha sido: 0,49 (DE: 1,03. El tiempo de espera en el Centro de Salud de MP ha sido: 10,86 minutos (DE: 8,27; en el Centro de Salud de Cardenete: 7,88 (DE: 4,55. 83,4 % de los usuarios de los dos Centros de Salud de conocen la posibilidad de libre elección de médico de cabecera. Se han encontrado diferencias estadísticamente significativas en 11 de los 21 ítems estudiados sobre calidad percibida de que consta el cuestionario CONCLUSIÓN. Los resultados de los componentes de la atención según el análisis factorial de los ítems de calidad percibida son coincidentes con los resultados de calidad percibida. De los dos grupos de usuarios estudiados, los que perciben

  6. DILEMA ECONÓMICO - AMBIENTAL DEL URBANISMO EN CIUDADES LATINOAMERICANAS

    Directory of Open Access Journals (Sweden)

    Néstor Garza

    2009-01-01

    Full Text Available En este artículo se plantea que la intervención sobre el funcionamiento de los mercados de suelo ha coincidido en Estados Unidos con el fenómeno de la suburbanización y una gama amplia de problemáticas ambientales asociadas a ésta. De otra parte, se argumenta que en América Latina no se ha seguido ese tipo de políticas, y se ha privilegiado intervenciones que han implicado ciudades compactas y de rentas altas, con problemas ambientales y urbanos por la escasa provisión de bienes públicos que viabilicen altas densidades. Se describe el proceso que dio lugar al ejercicio del urbanismo en el Primer Mundo y posteriormente en América Latina, y se detectan faltantes importantes en la conceptualización del fenómeno de la urbanización para el caso de esta última región. El artículo concluye que es inevitable confrontar un dilema económico-ambiental en el ejercicio del urbanismo, el cual se resume de la siguiente manera: la gestión activa de suelo implica precios bajos y suburbanización, con consecuencias no deseables, mientras que su ausencia implica precios altos con altas densidades que requieren costosas infraestructuras de soporte.

  7. Dilemas de pais e filhos no processo sucessório de empresas familiares

    Directory of Open Access Journals (Sweden)

    José Elias Flores Jr.

    2012-06-01

    Full Text Available Com o objetivo geral de destacar e analisar a vivência de dilemas de pais e filhos no que concerne ao processo sucessório em empresas familiares, desenvolveu-se pesquisa exploratória de orientação qualitativa a partir do pressuposto de que esses dilemas tenham papel determinante no planejamento (ou falta dele, execução e desfecho do processo sucessório, no futuro da empresa familiar e em suas chances de continuidade. No trabalho, buscou-se aliar o suporte teórico oferecido pela abordagem aplicada às empresas familiares às ideias de Bauman (2007a; 2007b; 2008 sobre a liquidez da existência e ao campo empírico referente a organizações com essas características, de um segmento específico de serviços. A coleta de dados deu-se por meio da realização de entrevistas individuais semiestruturadas que somaram um total de 12 sujeitos - cinco pais-sucedidos e sete filhos-sucessores -, todos eles atuantes em cinco pequenas e médias empresas familiares brasileiras. Nesse sentido, foram identificados dez dilemas principais a serem abordados no presente artigo. Desses, cinco foram dilemas relativos aos pais-sucedidos entrevistados e cinco foram dilemas relativos aos filhos-sucessores indicados pelos primeiros. Analisados à luz da literatura, os resultados indicam, como um aspecto com cunho conclusivo, que os dilemas dos pais-sucedidos entrevistados estão prioritariamente relacionados com a dualidade vida-morte, enquanto os dilemas dos filhos-sucessores estão centrados na questão de legitimação pessoal. Igualmente, identificou-se, a partir do objetivo principal proposto, que os referidos dilemas de pais-sucedidos e filhos-sucessores podem influenciar e inclusive serem determinantes para o trato e o desenvolvimento da questão sucessória dentro da empresa familiar. Por derradeiro, expõem-se as limitações da pesquisa e apresentam-se sugestões para futuros trabalhos sobre o tema.

  8. El sentido de las enfermedades por parásitos intestinales en poblaciones americanas, identificando dilemas bioéticos

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    María del Pilar Díaz Murillo

    2013-01-01

    Full Text Available Objetivo: Identificar sentidos que pueblos del continente americano le asignan a las parasitosis intestinales y plantear posibles conflictos o dilemas en las tomas de decisiones en diferentes actividades de salud producto del encuentro de valores distintos, campo de acción de la bioética. Metodología: Revisión bibliográfica de artículos sobre parasitosis intestinales que cumplieran los criterios de inclusión establecidos y suministraran aportes para la comprensión hermenéutica de las parasitosis intestinales y permitieran identificar dilemas bioéticos para actividades en salud resultantes del contacto entre las visiones émica y ética (de la biomedicina. Resultados: La construcción social de las parasitosis intestinales influye en su percepción de causalidad, nocividad y como problema de salud, lo cual afecta las acciones que la gente emprenda ante ellas. Se advierte que tales construcciones sociales pueden no coincidir con la perspectiva biomédica. Se observó que en algunas poblaciones la construcción social del cuerpo se relaciona con la percepción de efectos benéficos de los parásitos. La gente reconoce factores de riesgo pero esto no necesariamente conduce a comportamientos preventivos. Algunos estudios reconocen que la educación ha sido de tipo informativo, sin participación comunitaria, lo cual impide que la gente se identifique con ella y se sienta motivada a transformar su realidad. Se identificaron diversos dilemas bioéticos producto del contacto entre visiones de las poblaciones, y la biomedicina. Conclusiones: La aproximación émica permite entender la lógica de la población sobre las parasitosis intestinales e identificar disyuntivas bioéticas. Aunque la gente reconozca los riesgos de infección, la falta de comprensión de la perspectiva émica de los parasitismos por parte del personal de salud y las deficientes condiciones de vida permiten que no se produzcan transformaciones que incidan en la disminuci

  9. Resultados psicométricos preliminares de la escala de autoeficacia percibida en maestros de Lima

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    Manuel Fernández Arata

    2012-07-01

    Full Text Available Abstract The perceived self-efficacy is considered as an important concept in many areas of the behavior, especially in teaching performance and stress. This research paper reports the preliminary psychometric findings based on the Perceived Self-Efficacy Scale (Tschannen-Moran & Woolfolk, 2001 in 313 elementary teachers and 352 high school teachers in Lima, Peru. The results concerning item analysis, reliability and internal structure support the psychometric integrity of this instrument in both samples. These results also suggest cross-cultural comparability of the constructs assessed. Given the importance of perceived self-efficacy and stress intervention amongst teachers, this instrument provides a reliable and structurally valid system for measuring these factors. Resumen La autoeficacia percibida es un concepto importante en muchas áreas del comportamiento, y muy especialmente en el desempeño docente y en el estrés. Justamente, el presente artículo de investigación reporta los hallazgos psicométricos preliminares de la aplicación de la Escala de Autoeficacia Percibida (Tschannen-Moran & Woolfolk, 2001 en 313 maestros de enseñanza elemental y 352 de secundaria en Lima, Perú. Los resultados concernientes al análisis de ítems, confiabilidad y estructura interna respaldan la integridad psicométrica de este instrumento en ambos grupos de participantes. Estos resultados también sugieren la comparabilidad intercultural de los constructos evaluados. Dada la relevancia de la eficacia percibida en la investigación y la intervención sobre el estrés docente, el instrumento permite una vía métrica que puede dar información confiable y estructuralmente válida.

  10. Ansiedad, resiliencia e inteligencia emocional percibida en mujeres con cáncer de mama

    OpenAIRE

    García-Maroto Fernández, Sagrario

    2016-01-01

    Introducción. En el presente trabajo de investigación se ha estudiado la ansiedad, la resiliencia y la inteligencia emocional percibida en un grupo de mujeres con cáncer de mama y otro grupo de mujeres sin la enfermedad. Así mismo, se ha realizado el diseño, la aplicación y la evaluación de un programa de inteligencia emocional en un grupo de mujeres con cáncer de mama. - Contenido de la investigación. El marco teórico se centra en los constructos principales de estudio, ansiedad, resilien...

  11. Análisis de la calidad percibida por el cliente en la actividad hotelera

    OpenAIRE

    González-Arias, Mahé; Frías-Jiménez, Roberto Argelio; Gómez-Figueroa, Olga

    2016-01-01

    La Calidad Percibida del Servicio desde la perspectiva de satisfacción del cliente externo, es un elemento básico para comprender sus necesidades y expectativas. Por las ventajas que esto representa el objetivo principal de este trabajo fue el desarrollo de un procedimiento que permitió su análisis y medición en un hotel del Polo de Varadero. Entre las técnicas y herramientas utilizadas se encuentran: cuestionario SERVPERF, Procedimiento Valper y Matriz de decisión W-X. En el procesamiento y ...

  12. Inteligencia Contextual Percibida en el Deporte. Desarrollo y Validación de un Cuestionario

    OpenAIRE

    Luis Miguel Ruiz Pérez; José Luis Graupera Sanz; Virginia García Coll

    2014-01-01

    El propósito de este estudio ha sido el desarrollo y validación de un Cuestionario de Inteligencia Contextual Percibida en el Deporte en una muestra de deportistas españoles de diferente nivel de pericia. Participaron 2091 deportistas (1519 hombres y 572 mujeres) de edades comprendidas entre los 11 y los 59 años (M = 20,8; DT = 6,14). Los análisis factoriales exploratorio y confirmatorio mostraron que el cuestionario presentaba una estructura de tres dimensiones (inteligencia anticipatoria, i...

  13. Diferentes dominios de la autoeficacia percibida en relación con la agresividad adolescente

    OpenAIRE

    M. A. CARRASCO ORTIZ; M. V. DEL BARRIO GÁNDARA

    2002-01-01

    Se estudia la relación entre distintos dominios de la autoeficacia percibida y las conductas agresivas manifiestas. La muestra está compuesta por 543 niños de 8 a 15 años escolarizados en colegios públicos. Los resultados confirman una relación significativa entre estas dos variables. La autoeficacia académica, lúdica y en la petición de apoyo son las variables que modulaban las diferencias encontradas en los niveles de agresividad. Atendiendo al carácter predictivo de los distintos dominios ...

  14. Inteligencia emocional percibida y desgaste laboral en médicos internos de pregrado

    Directory of Open Access Journals (Sweden)

    R. Ortiz-Acosta

    Full Text Available Objetivo: Analizar la relación entre los niveles de inteligencia emocional percibida y desgaste laboral en médicos internos de pregrado. Sujetos y métodos: Para ello se utilizó la Trait Meta-Mood Scale, que evalúa la inteligencia emocional percibida, y el inventario de burnout de Maslach, en 44 médicos internos de pregrado de tres hospitales de los Servicios de Salud de Sonora. Resultados: El factor de atención emocional se relaciona negativamente con agotamiento. Claridad correlaciona de manera positiva con reparación emocional y realización personal, y de forma negativa con agotamiento y despersonalización. Reparación de las emociones correlaciona de forma negativa con agotamiento y despersonalización, y de manera positiva con realización personal. Los análisis de regresión revelaron que el desgaste laboral del médico de pregrado se explicaba por una baja atención emocional y falta de claridad en sus emociones. Conclusión: Estos hallazgos evidencian que ciertos factores emocionales deben tenerse en cuenta para explicar el desgaste laboral en el médico interno de pregrado.

  15. Diferencias individuales como predictoras de la salud y calidad de vida percibida en embarazadas

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    Leticia Guarino

    2012-01-01

    Full Text Available Objetivo. Determinar en qué medida ciertas diferencias individuales como el estilo emocional (rumiación e inhibición emocional, la sensibilidad egocéntrica negativa y los estilos de afrontamiento predicen la salud y calidad de vida percibida en mujeres embarazadas. Método. Un grupo de 94 mujeres embarazadas venezolanas, en el primer trimestre de gestación, completaron cuestionarios de estilo emocional, sensibilidad emocional, afrontamiento, salud percibida y calidad de vida. Resultados. Un estilo emocional negativo, conjuntamente con el uso de formas de afrontamiento disfuncionales durante el embarazo predicen un mayor deterioro en la salud y calidad de vida de estas mujeres durante su primer trimestre de gestación. Otros estilos de afrontamiento, como la interpretación positiva, funcionan más bien como factor protector de la salud. Conclusion. El estudio revela la importancia de evaluar las diferencias individuales de las embarazadas y desarrollar programas de intervención sobre estos aspectos, a fin de promover una mejor salud y calidad de vida durante este importante proceso en la mujer.

  16. La centralidad en las comunicaciones y la influencia percibida en los pequeños grupos

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    Nancy Noemi Terroni

    Full Text Available Este trabajo reporta los resultados de medidas del análisis de redes en la comunicación de pequeños grupos que resuelven una tarea de recuperación de memoria y su asociación con la influencia percibida. El reactivo empleado es una historia y los 65 participantes, alumnos de la Universidad Nacional de Mar del Plata, debieron reconstruir la misma primero en forma individual, luego grupal colaborativa y nuevamente en forma individual. Se registraron las interacciones grupales con comunicación cara a cara y mediada por computadora; se analizaron las medidas de prominencia, la centralidad y el prestigio de la comunicación y el tipo de alocución, orientado a la gestión grupal o hacia la tarea. Se observaron asociaciones significativas entre las medidas reticulares y la influencia percibida para ambos medios de comunicación y se hallaron diferencias en la comunicación de gestión grupal. Se discuten estos resultados con relación a las restricciones que imponen los canales de comunicación mediados.

  17. Procedimiento para la evaluación de la calidad percibida de los servicios bancarios

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    Roxana González Alvarez

    2013-07-01

    Full Text Available En el presente artículo se describe un procedimiento para la evaluación de la calidad percibida de los servicios bancarios, el cual cuenta con cuatro etapas y trece pasos. La propuesta garantiza la evaluación y mejora de la calidad percibida con un enfoque de gestión por procesos y mejora continua. Para la recopilación de información se utilizaron técnicas tales como: entrevistas, tormenta de ideas, revisión de documentos, trabajo con expertos, trabajo en equipo y observación directa. Se hace uso de herramientas clásicas de la calidad y de gestión de procesos, así como la técnica 5Ws y 1H (What, Why, Where, Who, When, How y la metodología de Proceso Esbelto. Como resultados fundamentales de la investigación se identificaron las principales brechas de insatisfacción en la calidad del servicio, a partir de las percepciones de los clientes mediante el uso del cuestionario Servqual, así como la obtención de una calificación global de la calidad del servicio. Se determinó que para las 22 declaraciones del cuestionario Servqual, las percepciones de los clientes no superan las expectativas, donde las brechas con menor índice de calidad se relacionan con el tiempo de servicio para lo cual se propone un conjunto de acciones que contribuyen a la mejora de la calidad percibida. In the present paper is described a procedure for evaluating the perceived quality of banking services which has four stages and thirteen steps. The proposal ensures the evaluation and improvement of the perceived quality with a focus on process management and continuous improvement. For data collection are used techniques such as: interviews, brainstorming, review of documents, work with experts, teamwork and direct observation. It makes use of classical tools of quality and process management as well as 5Ws and 1H technique (What, Why, Where, Who, When, How and the methodology of Lean Process. As fundamental research results were identified the main gaps of

  18. Diferentes dominios de la autoeficacia percibida en relación con la agresividad adolescente

    Directory of Open Access Journals (Sweden)

    M. A. CARRASCO ORTIZ

    2002-01-01

    Full Text Available Se estudia la relación entre distintos dominios de la autoeficacia percibida y las conductas agresivas manifiestas. La muestra está compuesta por 543 niños de 8 a 15 años escolarizados en colegios públicos. Los resultados confirman una relación significativa entre estas dos variables. La autoeficacia académica, lúdica y en la petición de apoyo son las variables que modulaban las diferencias encontradas en los niveles de agresividad. Atendiendo al carácter predictivo de los distintos dominios de autoeficacia, la autoeficacia académica fue la variable que predijo un mayor porcentaje de varianza explicada en la agresividad y, en menor medida, la autoeficacia en el deporte.

  19. Tareas grupales en ambientes virtuales. Dificultades percibidas y aprendizajes logrados por estudiantes universitarios

    Directory of Open Access Journals (Sweden)

    Analía Claudia Chiecher

    2011-01-01

    Full Text Available El artículo describe una experiencia didáctica que consistió en la implementación de una e-actividad con estudiantes universitarios que cursaban tradicionalmente con modalidad presencial. Participaron 91 estudiantes de tres asignaturas que, reunidos en 27 grupos, dieron respuesta a la e-actividad en el entorno virtual. Al finalizar la experiencia se realizó una entrevista grupal y se hizo una pregunta acerca de las preferencias por el trabajo grupal o individual. Los resultados se orientan a mostrar las dificultades percibidas por los alumnos durante la realización de la e-actividad, los aprendizajes que reconocieron haber logrado y sus preferencias respecto del trabajo grupal o individual en tareas de este tipo.

  20. Inteligencia Contextual Percibida en el Deporte. Desarrollo y Validación de un Cuestionario

    Directory of Open Access Journals (Sweden)

    Luis Miguel Ruiz Pérez

    2014-01-01

    Full Text Available El propósito de este estudio ha sido el desarrollo y validación de un Cuestionario de Inteligencia Contextual Percibida en el Deporte en una muestra de deportistas españoles de diferente nivel de pericia. Participaron 2091 deportistas (1519 hombres y 572 mujeres de edades comprendidas entre los 11 y los 59 años (M = 20,8; DT = 6,14. Los análisis factoriales exploratorio y confirmatorio mostraron que el cuestionario presentaba una estructura de tres dimensiones (inteligencia anticipatoria, inteligencia táctica e inteligencia competitiva, además de permitir obtener la obtención de un valor de la escala general denominado Inteligencia Contextual en el Deporte. Las propiedades psicométricas de validez y la fiabilidad del instrumento fueron excelentes para poder ser empleado en estudios en los que esta dimensión sea de interés.

  1. Morbilidad percibida y utilización de servicios de salud

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    José Díaz Novás

    1996-06-01

    Full Text Available Se realizó un estudio descriptivo sobre morbilidad percibida y utilización de servicios de salud en una muestra de la población adulta de la Zona 5 (sector B de la comunidad de Alamar. Encontramos que el 68,9 % de las personas encuestadas reportó algún síntoma o padecimiento en el mes anterior; el 45,6 % consultó a un médico; el 2,3 % fue remitido al hospital y el 1,1 % ingresó. Se plantea que sólo un pequeño porcentaje de las personas que enfermaron fueron atendidas e ingresadas en el hospital y que la atención primaria se resuelven más del 90 % de los problemas de salud de la población.

  2. Ant- and Ant-Colony-Inspired ALife Visual Art.

    Science.gov (United States)

    Greenfield, Gary; Machado, Penousal

    2015-01-01

    Ant- and ant-colony-inspired ALife art is characterized by the artistic exploration of the emerging collective behavior of computational agents, developed using ants as a metaphor. We present a chronology that documents the emergence and history of such visual art, contextualize ant- and ant-colony-inspired art within generative art practices, and consider how it relates to other ALife art. We survey many of the algorithms that artists have used in this genre, address some of their aims, and explore the relationships between ant- and ant-colony-inspired art and research on ant and ant colony behavior.

  3. Adaptación Universitaria y Su Relación con la Salud Percibida en Una Muestra de Jóvenes de Perú

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    CECILIA CHAU

    2014-01-01

    Full Text Available El propósito de este estudio fue analizar la relación entre la salud percibida y la adaptación a la vida universitaria de un grupo de jóvenes estudiantes de Lima, Perú. Para ello, se aplicó el Cuestionario de Adaptación Universitaria ( Q va -R y una medida de salud percibida, a una muestra de 281 estudiantes universitarios. Los resultados mostraron una relación positiva entre la salud percibida y las cinco áreas que miden la adaptación universitaria. El área Personal presentó la mayor relación con la salud percibida. Esto evidenció la importancia de la relación que existe entre la habilidad para adaptarse a la vida universitaria y la percepción de salud de los alumnos.

  4. Dilemas e conflitos de ser mãe na vigência do HIV/Aids Dilemas y conflictos de ser madre en casos de VIH/Sida Dilemmas and conflitcs of being a mother with HIV/Aids

    Directory of Open Access Journals (Sweden)

    Marli Teresinha Gimeniz Galvão

    2010-06-01

    Full Text Available Objetivou-se apreender os dilemas e conflitos revelados por mulheres que engravidaram na vigência da infecção pelo HIV/Aids. Estudo qualitativo com oito mulheres atendidas em ambulatório em Fortaleza-CE. Mediante entrevistas observou-se que as mulheres gestam com expectativa do resultado da sorologia do concepto; depois de nascidos vivenciam incertezas e mantêm superproteção da criança. Relatam maneiras inadequadas da comunicação do diagnóstico e pouca orientação para gestar em face do HIV. As mulheres transformam o desejo de ser mãe em realidade. Para elas, lidar com uma criança com possibilidade de contrair infecção pelo HIV é algo além de sua capacidade. Conclui-se ser essencial oferecer suporte emocional e social para essas mulheres independente das fases da vida.La finalidad fue aprehender los dilemas y conflictos revelados por mujeres infectadas por el VIH/Sida que quedaron embarazadas. Estudio cualitativo con ocho mujeres atendidas en ambulatorio en Fortaleza-CE. Mediante entrevistas fue observado que las mujeres gestan con expectativa del resultado de la serología del concepto; después de nacidos viven incertidumbres y mantienen protección exagerada del niño. Relatan maneras inadecuadas de comunicar el diagnóstico y poca orientación para gestar ante el VIH. Las mujeres transforman el deseo de ser madre en realidad. Para ellas, lidiar con un niño con posibilidad de contraer infección por el VIH es algo más allá de su capacidad. Se concluye que es esencial ofrecer soporte emocional y social para esas mujeres independientemente de las fases de la vida.This study aimed to apprehend the dilemmas and conflicts revealed by women infected with HIV/Aids who got pregnant. This qualitative study involved eight women attended at an outpatient clinic in Fortaleza-CE. Through interviews, it was observed that the women go through their pregnancy with expectations about their child's serological status; after birth, they

  5. Riding with the ants

    NARCIS (Netherlands)

    Duarte, A. P. M.; Attili-Angelis, D.; Baron, N. C.; Groenewald, Johannes Z.; Crous, Pedro W.; Pagnocca, F. C.

    Isolates of Teratosphaeriaceae have frequently been found in the integument of attine ants, proving to be common and diverse in this microenvironment. The LSU phylogeny of the ant-isolated strains studied revealed that they cluster in two main lineages. The first was associated with the genus

  6. La actitud del vendedor ante las innovaciones tecnológicas y su influencia en su desempeño en las ventas

    Directory of Open Access Journals (Sweden)

    José Fernando Barahona Vinasco

    2017-09-01

    Full Text Available El objetivo de este trabajo es determinar cómo la actitud que tienen los vendedores ante la tecnología puede representar un factor decisivo en la implementación de los procesos de automatización de la fuerza de ventas (afv. Se parte del modelo de aceptación tecnológica (tam, por su sigla en inglés, que asume que la actitud viene determinada por la utilidad percibida y por la facilidad de uso de esta, e introducimos como novedad en el modelo su relación con el desempeño. Se contrasta el modelo conceptual en una muestra de vendedores colombianos a través de un modelo de ecuaciones estructurales. Los resultados establecen que la percepción de la facilidad de uso de la tecnología influye positivamente en su utilidad percibida, al igual que la percepción de facilidad de uso influye positivamente en la actitud hacia su uso. Sin embargo, la utilidad percibida de la tecnología no muestra una relación directa frente a la actitud hacia su uso, y de igual forma no existe relación directa entre la actitud hacia el uso y el desempeño en ventas.

  7. Violencia e inseguridad contextual percibida y roles en bullying en escolares mexicanos

    Directory of Open Access Journals (Sweden)

    Carlos Hidalgo-Rasmussen, México.

    2015-07-01

    Full Text Available (analítico: Estudio observacional, transversal y analítico realizado con 2201 niños y adolescentes, estudiantes de primaria, secundaria y preparatoria de México con el objetivo de analizar la relación entre sus percepciones de violencia del país y su municipio, inseguridad en su colonia y escuela y su rol en bullying escolar: observador, víctima o acosador. En México existen dos preocupantes fenómenos: la violencia vinculada al narcotráfico y los eventos de bullying escolar y en este trabajo se buscó aportar a explicar sus posibles relaciones. Se usó un cuestionario autoaplicado en línea y análisis estadístico con Ji cuadrado y regresión logística encontrando algunas asociaciones significativas entre la violencia, inseguridad percibida y los roles en bullying. Las variables contextuales como la violencia deben considerarse en programas de prevención y atención del bullying.

  8. Relación entre variables psicosociales y la salud percibida

    Directory of Open Access Journals (Sweden)

    Igor Esnaola

    2011-01-01

    Full Text Available El objetivo de este estudio ha sido analizar las relaciones entre el autoconcepto físico, el índice de masa corporal y la actividad físico-deportiva con la salud percibida. La muestra está compuesta por 518 personas adultas entre los 19.4 y 49.7 años de edad (M = 30.79 años; DE = 9.24, 301 mujeres (58.1% y 217 varones (41.9%. Los resultados señalan que los sujetos que tienen un mejor autoconcepto físico se perciben con un alto grado de salud en comparación con los sujetos que tienen un autoconcepto físico bajo, los cuales creen que su salud no es buena. En cuanto al análisis de regresión logística múltiple, los resultados han confirmado que el autoconcepto físico está significativamente relacionado con la percepción de la salud tanto en mujeres como en varones. Asimismo, en la muestra femenina dos subdominios han aparecido relacionados significativamente con la percepción de la salud, la condición física y el atractivo físico.

  9. Violencia e inseguridad contextual percibida y roles en bullying en escolares mexicanos

    Directory of Open Access Journals (Sweden)

    Carlos Hidalgo-Rasmussen

    2015-01-01

    Full Text Available Estudio observacional, transversal y analítico realizado con 2201niños y adolescentes, estudiantes de primaria, secundaria y preparatoria de México con el objetivode analizar la relación entre sus percepciones de violencia del país y su municipio, inseguridaden su colonia y escuela y su rol en bullying escolar: observador, víctima o acosador. En Méxicoexisten dos preocupantes fenómenos: la violencia vinculada al narcotráfico y los eventos de bullyingescolar y en este trabajo se buscó aportar a explicar sus posibles relaciones. Se usó un cuestionarioautoaplicado en línea y análisis estadístico con Ji cuadrado y regresión logística encontrandoalgunas asociaciones significativas entre la violencia, inseguridad percibida y los roles en bullying.Las variables contextuales como la violencia deben considerarse en programas de prevención yatención del bullying.

  10. Sick ants become unsociable

    DEFF Research Database (Denmark)

    Bos, Nicky Peter Maria; Lefevre, T.; Jensen, A.B.

    2012-01-01

    Parasites represent a severe threat to social insects, which form high-density colonies of related individuals, and selection should favour host traits that reduce infection risk. Here, using a carpenter ant (Camponotus aethiops) and a generalist insect pathogenic fungus (Metarhizium brunneum), we...... show that infected ants radically change their behaviour over time to reduce the risk of colony infection. Infected individuals (i) performed less social interactions than their uninfected counterparts, (ii) did not interact with brood anymore and (iii) spent most of their time outside the nest from...... day 3 post-infection until death. Furthermore, infected ants displayed an increased aggressiveness towards non-nestmates. Finally, infected ants did not alter their cuticular chemical profile, suggesting that infected individuals do not signal their physiological status to nestmates. Our results...

  11. Exploración de las emociones percibidas en cuatro grupos de edad

    Directory of Open Access Journals (Sweden)

    Claudia J. Arias

    2013-12-01

    Full Text Available En el presente artículo se presentan los resultados de un estudio empírico de comparación de grupos de edad sobre Emociones Percibidas. Los antecedentes sobre este tema son escasos –tanto a nivel internacional como local- y poco claros, por lo que se considera necesario explorar el constructo. Se utilizó la versión validada para población local  de las escalas de Lawton  (Intensidad del afecto; Moderación del afecto positivo; Búsqueda de sensaciones; Control cognitivo; Madurez emocional; Disimulación afectiva; Responsividad psicofisiológica; Variabilidad afectiva; Duración del afecto y Rapidez de la respuesta afectiva. Se seleccionó una muestra intencional de 480 sujetos de ambos sexos, 240 de la ciudad de Mar del Plata y 240 de la ciudad de Buenos Aires. Se encontraron puntajes significativamente más altos en los grupos de adultos mayores en las dimensiones Moderación del afecto positivo, el Control cognitivo, Disimulación afectiva y la Madurez emocional. No se encontraron diferencias significativas entre los distintos grupos de edad en las dimensiones Intensidad del afecto y Responsividad psicofisiológica. Los resultados son consistentes con los antecedentes de investigación que señalan que los adultos mayores presentan elevados niveles de habilidades de regulación emocional, lo que fortalece la mirada de la psicología positiva y del curso vital sobre el envejecimiento.  

  12. EVALUACIÓN DE LA CALIDAD DEL SERVICIO PERCIBIDA EN ENTIDADES BANCARIAS A TRAVÉS DE LA ESCALA SERVQUAL

    Directory of Open Access Journals (Sweden)

    Roxana González Álvarez

    2015-01-01

    Full Text Available El presente trabajo se realizó en una sucursal bancaria en la provincia de Cienfuegos, Cuba,durante los últimos tres trimestres del año 2013 con el objetivo fundamental de evaluar y mejorarla calidad percibida con un enfoque de gestión por procesos y mejora continua. Para ello, sediseñó e implementó un procedimiento para la evaluación de la calidad percibida de los serviciosbancarios basado en la escala multidimensional Servqual. Para la recopilación de información seutilizaron técnicas tales como: entrevistas, tormenta de ideas, revisión de documentos, trabajocon expertos, trabajo en equipo y observación directa. Se hizo uso de herramientas clásicas dela calidad y de gestión de procesos, así como la técnica 5W y 1H, y la metodología de ProcesoEsbelto. Como resultados fundamentales de la investigación se identificaron las principalesbrechas de insatisfacción en la calidad del servicio a partir de las percepciones de los clientes,así como la obtención de una calificación global de la calidad del servicio. Se determinó que paralas 22 declaraciones del cuestionario Servqual las percepciones de los clientes no superan lasexpectativas. Las brechas con menor índice de calidad son aquellas que se relacionan con eltiempo de servicio, por lo que se propone un conjunto de acciones que contribuyan a la mejorade la calidad percibida.

  13. Condiciones de trabajo y morbilidad percibidas entre mineros de carbón en Guachetá, Colombia

    OpenAIRE

    Jimenez Forero, Claudia Patricia

    2014-01-01

    Introducción: En Colombia la investigación sobre condiciones de trabajo y salud en minería carbonífera es escasa y no considera la percepción de la población expuesta y sus comportamientos frente a los riesgos inherentes. Objetivo: Determinar la asociación entre las condiciones de trabajo y morbilidad percibidas entre trabajadores de minas de carbón en Guachetá, Cundinamarca. Materiales y métodos: Se realizó un estudio transversal con 154 trabajadores seleccionados aleatoriamente del tota...

  14. Turismo rural no município da Lapa - PR: perspectivas e dilemas

    Directory of Open Access Journals (Sweden)

    Joyce Meri Sera MARQUES

    2003-12-01

    Full Text Available Análise das perspectivas e dilemas pelas quais passa a consolidação do turismo rural no Município da Lapa - PR, no período de 2001 a 2002, sob o enfoque crítico, com o propósito de reconhecimento dos aspectos econômicos e sociais que envolvem a atividade do turismo rural, bem como todas as pessoas envolvidas. Discorre sobre aspectos gerais quanto à economia local, bem como a distribuição populacional nas atividades econômicas desenvolvidas. Salienta as evoluções tecnológicas pelas quais as propriedades envolvidas passaram a fim de atender melhor seus visitantes e a demanda crescente. Para tal análise foram feitas entrevistas com os proprietários em dois momentos, um em 2001, quando se contavam apenas quatro propriedades, e outra em 2002, quando se contavam nove proprietários. As aspirações, dilemas e projetos futuros foram destacados de modo a estabelecer o turismo rural como uma alternativa de atividade para estas propriedades.

  15. ONGs, vulnerabilidade juvenil e reconhecimento cultural: eficácia simbólica e dilemas

    Directory of Open Access Journals (Sweden)

    Paulo Artur Malvasi

    Full Text Available A busca pelo reconhecimento cultural como estratégia no enfrentamento da vulnerabilidade entre jovens tornou-se predominante entre as ONGs (organizações não governamentais brasileiras. Após dez anos de crescimento desta forma de ação, analisamos sua eficácia simbólica e seus dilemas. O artigo debate, inicialmente, conceitos e práticas envolvidas nesse cenário. Em seguida, volta-se para o campo das ONGs brasileiras que atuam com jovens em situação de vulnerabilidade, por meio de atividades artísticas e culturais, com o intuito de reconhecer os elementos simbólicos presentes neste contexto. Apresenta-se, ainda, um estudo de caso sobre a experiência de uma delas e destaca-se um dilema comum às ações das ONGs no enfrentamento da vulnerabilidade juvenil: o de conciliar as ações de caráter cultural que valorizam o repertório particular dos jovens de classes populares com a viabilização do acesso a estruturas e recursos básicos dos quais estão afastados.

  16. Escala VGP de violencia de género percibida en relaciones de pareja en la población de Costa Rica

    OpenAIRE

    Salom Farré, Clara

    2015-01-01

    Se analizan las respuestas de una muestra de 325 estudiantes de distintas facultades de la universidad de Costa Rica a la escala de violencia percibida. Esta escala evalúa la capacidad de las personas para detectar situaciones de violencia en las relaciones de pareja. El objetivo es valorar el grado en que esta violencia es percibida por la población de estudiantes universitarios de Costa Rica, y analizar si esta capacidad de detección varía en función de otras variables como puede ser el sex...

  17. Construcción y validación del Inventario Autoeficacia Percibida para el Control de Peso

    Directory of Open Access Journals (Sweden)

    Yelitze Román

    2007-01-01

    Full Text Available Se presenta la construcción y propiedades psicométricas del Inventario de Autoeficacia Percibida para el Control del Peso, destinado a medir la autoeficacia percibida en tres áreas del control del peso: estilo de alimentación, influencia de los estímulos externos en la conducta de sobreingesta y patrones de actividad física. A partir de una revisión bibliográfica exhaustiva, encuesta de opinión y consulta a 4 expertos en el área, se elaboraron 120 ítems. En una muestra de 193 estudiantes se seleccionaron 37 ítems sobre la base de criterios estadísticos. Se realizaron estudios de fiabilidad y validez en una muestra de 439 estudiantes. El análisis factorial muestra 3 factores que explican el 44,083% de la varianza. Los índices de consistencia interna son satisfactorios para cada factor: 0,88, 0,91, y 0,88. Los resultados obtenidos se discuten y se presentan algunas sugerencias para futuros estudios.

  18. Commentary: Warring ants

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 27; Issue 2. Commentary: Warring ants: Lessons from Lanchester's laws of combat? Renee M Borges. Volume 27 Issue 2 March 2002 pp 75-78. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/jbsc/027/02/0075-0078 ...

  19. Antílope

    Directory of Open Access Journals (Sweden)

    Pedro Anderson Martinho Moçambique

    2015-10-01

    Full Text Available Essa espécie de antílope só é encontrada em território angolano, sendo assim um símbolo nacional. Segundo a mitologia africana é símbolo de vivacidade, velocidade e beleza - Angola.

  20. Antílope

    Directory of Open Access Journals (Sweden)

    Pedro Anderson Martinho Moçambique

    2011-04-01

    Full Text Available Essa espécie de antílope só é encontrada em território angolano, sendo assim um símbolo nacional. Segundo a mitologia africana é símbolo de vivacidade, velocidade e beleza - Angola.

  1. Fire Ant Allergy

    Science.gov (United States)

    ... venom in a fire ant sting will kill bacteria and some of your skin cells. This results in the formation of a blister that fills with a cloudy white material in about 24 hours. While this looks like a pus-filled lesion that should be drained, ...

  2. "Ant-egg" cataract revisited

    DEFF Research Database (Denmark)

    Clemmensen, Kåre; Enghild, Jan J; Ivarsen, Anders

    2017-01-01

    -ray scans and electron microscopy. The purpose of this study was to further characterize "ant-egg" cataract using modern technology and display the history of the "ant-eggs" after cataract extraction. METHODS: "Ant-eggs" were examined using Heidelberg SPECTRALIS Optical Coherence Tomography (OCT...

  3. Ant Colony Optimization for Control

    NARCIS (Netherlands)

    Van Ast, J.M.

    2010-01-01

    The very basis of this thesis is the collective behavior of ants in colonies. Ants are an excellent example of how rather simple behavior on a local level can lead to complex behavior on a global level that is beneficial for the individuals. The key in the self-organization of ants is communication

  4. Enfermagem e práticas esportivas: aprendendo com os dilemas éticos Enfermería y prácticas deportivas: aprendiendo con los dilemas éticos Nursing and sport practices: learning with ethical dilemas

    Directory of Open Access Journals (Sweden)

    Inacia Sátiro Xavier de França

    2007-12-01

    Full Text Available Objetivou-se descrever as dificuldades relacionadas aos primeiros socorros durante uma olimpíada estudantil e correlacionar a experiência vivida com aspectos técnicos, científicos e éticos recomendados para a atuação do enfermeiro quando da prestação de primeiros socorros. O relato tomou por base a produção de dados no contexto da atuação dos socorristas e de uma oficina de consenso para solucionar dilema ético. Descreve-se o processo de tomada de decisão ética, os recursos materiais disponíveis, os agravos à integridade física dos atletas e as intervenções executadas. Conclui-se que o esporte tem caráter de medicina preventiva e curativa que exige o compromisso moral dos organizadores de prover os recursos materiais necessários às possíveis intervenções médicas por ocasião de algum dano sofrido pelos atletas.Este relato tiene como objetivo identificar las dificultades relacionadas a los primeros socorros realizados a atletas durante una olimpíada estudiantil y correlacionar la experiencia vivida con aspectos técnicos, científicos y éticos recomendados para la actuación del enfermero cuando está prestando los primeros socorros. El presente relato tomó por base la producción de datos en el contexto de la actuación de los socorristas y de un taller que buscaba solucionar dilema ético haciendo un análisis sobre la práctica de los socorristas. Se describe el proceso de tomada de decisión ética, los recursos materiales disponibles, los agravios a la integridad física dos atletas y las intervenciones ejecutadas. Se concluye que el deporte tiene el carácter de medicina preventiva y curativa que exige el compromiso moral de los organizadores de proveer los recursos materiales necesarios a las posibles intervenciones médicas por ocasión de algún daño sufrido por los atletas.This study aimed to identify the difficulties related to the first aids during one students competition and also it correlates the

  5. Interacción de la cohesión en la eficacia percibida, las expectativas de éxito y el rendimiento en equipos de baloncesto

    Directory of Open Access Journals (Sweden)

    Francisco Miguel Leo Marcos

    2010-01-01

    Full Text Available El presente estudio analiza las relaciones entre la cohesión y la autoeficacia, la eficacia colectiva, la eficacia percibida por los compañeros, la eficacia percibida por el entrenador, las expectativas de éxito y el rendimiento colectivo. La muestra está formada por 61 participantes pertenecientes a seis equipos baloncesto federados. Se utilizaron diversos instrumentos para valorar la cohesión, la eficacia percibida y las expectativas de éxito, y el rendimiento se midió a través de la clasificación. Los resultados obtenidos señalan la relación positiva entre la eficacia percibida con los cuatro factores de la cohesión, tanto los aspectos sociales como de tarea. Además, se puede afirmar que los jugadores que perciben mayor grado de cohesión se relacionan con los jugadores que perciben mayores expectativas de éxito y obtienen mayor rendimiento.

  6. Dilema cultural en la escuela: el caso de la laicidad educativa

    Directory of Open Access Journals (Sweden)

    Sergio Pérez Sánchez

    2002-01-01

    Full Text Available La laicidad educativa en México ha sido históricamente parte de una agenda en permanente conflicto entre el Estado, la jerarquía religiosa y otros actores sociales. En el contexto de la diversidad religiosa y de su expresión en espacios secularizados como la escuela, en el presente artículo se ofrecen algunos elementos de análisis y reflexión referentes a cómo en las prácticas y procesos escolares, alumnos y padres de familia procedentes de hogares cuyo ejercicio religioso corresponde a la denominación Pentecostés y a los Testigos de Jehová en comunidades indígenas, viven en dilema constante con ciertos contenidos escolares, prácticas cívicas y sociales asociadas a la laicidad educativa.

  7. Las posibilidades de la terapia génica y sus dilemas bioéticos

    OpenAIRE

    Mejía, Orlando

    2005-01-01

    La terapia génica tiene, de acuerdo con Anderson, cuatro niveles de aplicación: las células somáticas, las células germinales, la terapia perfectiva y la manipulación eugenésica. Se hace un análisis de los dilemas bioéticos en cada nivel de terapia y se plantea el denominado Argumento Evolutivo para cuestionar los deseos de algunos científicos de iniciar terapia génica de células germinales. De igual manera, se advierte de los peligros de iniciar terapia perfectiva y la manipulación eugénica ...

  8. Dilemas genéticos y la Iglesia Católica

    Directory of Open Access Journals (Sweden)

    Juan María Velasco, SJ

    2017-01-01

    Full Text Available En las sociedades occidentales, en las que conviven múltiples paradigmas éticos, los dilemas que plantea la genética son entendidos y resueltos de distintas maneras, según el modo de concebir quién es el ser humano y cuáles son los derechos que avalan su dignidad. En este artículo se estudian los argumentos y los criterios que se ofrecen desde el Magisterio de la Iglesia Católica para tomar conciencia y decidir, conforme a esa visión creyente de la realidad, en los conflictos bioéticos que se generan en esta área del saber.

  9. Familia, género y migración de varones tamaulipecos: dilemas generacionales

    Directory of Open Access Journals (Sweden)

    Oscar Misael Hernández Hernández

    2015-01-01

    Full Text Available Con base en los resultados de un estudio antropológico, en este trabajo se exploran las experiencias migratorias de dos generaciones de varones tamaulipecos. A partir tanto de los relatos derivados de entrevistas con algunos hombres y mujeres adultos, quienes emigraron de localidades y zonas rurales del suroeste de Tamaulipas hacia Ciudad Victoria, la capital del estado, entre 1960 y 1970, como de los de hombres jóvenes, algunos hijos de los primeros, que emigraron de dicha ciudad a Estados Unidos a inicios del siglo xxi. Aquí el argumento es que la emigración de los varones de las dos generaciones estuvo inmersa en dilemas tanto familiares como de género al cuestionarse, negociarse e incluso redefinirse la decisión de realizar la emigración interna o trasnacional.

  10. Entregas, adopciones y dilemas en el campo de organismos destinados a la infancia

    Directory of Open Access Journals (Sweden)

    Carla Villalta

    2011-01-01

    Full Text Available http://dx.doi.org/10.1590/S0104-026X2011000100008 En este artículo se analizan los debates y dilemas que plantean las denominadas“entregas directas” en el campo de instituciones y agentes responsables de conceder lasadopciones de niños. Este término designa la entrega que las madres u otros miembros de lafamilia biológica realizan de sus niños a otras personas para que los adopten. Para dar cuentade los significados actualmente asociados a estas prácticas, por un lado, se describe y analizael proceso a través del cual el procedimiento de la entrega de niños por escritura pública fuesuprimido de la legislación argentina y, por otro lado, se focaliza el análisis en casos deadopciones legales de niños que fueron entregados en forma directa por sus madres y/ofamilias de origen. A través de este análisis, se examinan las formas que la intervención estatalasume cuando tiene por objetivos proteger a una población considerada ‘vulnerable’ y combatirel ‘tráfico de niños’. Esta indagación conduce a explorar el dilema que representa la adopciónde niños en una sociedad atravesada por profundas desigualdades sociales, y a reflexionarsobre cuáles son los derechos que les son reconocidos a aquellas mujeres para quienes laentrega de un hijo en adopción constituye una opción dentro de un limitado abanico de opciones.

  11. Aprendizaje autónomo y trabajo en equipo: reflexiones desde la competencia percibida por los estudiantes universitarios

    Directory of Open Access Journals (Sweden)

    Mª Soledad Ibarra Sáiz

    2011-01-01

    Full Text Available Este trabajo está centrado en presentar los principales resultados que sobre el nivel de competencia percibida manifiestan los estudiantes universitarios en dos competencias transversales (aprendizaje autónomo y trabajo en equipo. Los resultados se obtienen sobre una muestra de 2.556 estudiantes pertenecientes a diez universidades españolas. Destaca la necesidad de impulsar en los estudios universitarios estrategias que favorezcan un mayor grado de iniciativa de los estudiantes en un aprendizaje efectivo, estratégico y permanente. En este sentido se hace necesario educar a profesorado y estudiantes en su capacidad evaluadora para que puedan poner en práctica procesos de evaluación participativa que favorezcan el aprendizaje a lo largo de la vida.

  12. Runtime analysis of the 1-ANT ant colony optimizer

    DEFF Research Database (Denmark)

    Doerr, Benjamin; Neumann, Frank; Sudholt, Dirk

    2011-01-01

    The runtime analysis of randomized search heuristics is a growing field where, in the last two decades, many rigorous results have been obtained. First runtime analyses of ant colony optimization (ACO) have been conducted only recently. In these studies simple ACO algorithms such as the 1-ANT...... that give us a more detailed impression of the 1-ANT’s performance. Furthermore, the experiments also deal with the question whether using many ant solutions in one iteration can decrease the total runtime....

  13. Educación emocional y satisfacción con la vida percibida en un grupo de adultos mayores

    Directory of Open Access Journals (Sweden)

    Adriana del Pilar Perugache Rodríguez

    2016-07-01

    Full Text Available La investigación tuvo como objetivo determinar el efecto de un Programa en Educación Emocional sobre la percepción de la satisfacción con la vida en un grupo de Adultos Mayores. Materiales y método: el trabajo realizado fue de tipo explicativo y empleó un diseño experimental. Se evaluó inicialmente el nivel de la variable dependiente, en los grupos experimental y control a través de la prueba Índice de Satisfacción Vital (ISV –A adaptación de la escala original validada por Zegers, Rojas y Förstein (2009; con una consistencia interna de 0, 80, y una validez de 0.84. Posteriormente se implementó el Programa de Educación Emocional en el grupo experimental y finalmente, se aplicó el pos-test en los dos grupos. El análisis de los datos se realizó con el paquete estadístico SPSS versión 0.20. Debido a que no se cumplió con el supuesto de normalidad se aplicó la prueba de Wilcoxon para muestras relacionadas y la U de Mann Whitney para las muestras independientes. Resultados: el programa mejoró los niveles de satisfacción con la vida percibida en el grupo experimental, obteniendo un p0,05. Conclusiones: El programa incrementa los niveles de satisfacción con la vida percibida en adultos mayores.

  14. Relación de la competencia motriz percibida con la práctica físico-deportiva

    Directory of Open Access Journals (Sweden)

    Pedro Hell\\u00EDn G\\u00F3mez

    2006-01-01

    Full Text Available En esta investigación queremos comprobar la relación existente entre la percepción de competencia motriz con los hábitos de práctica físico-deportiva de los sujetos. Para ello establecemos relaciones biunívocas entre la competencia percibida y variables sociodemográficas (edad, género y nivel de estudios, nivel de práctica, tiempo dedicado a la misma, carácter individual o colectivo de la práctica físico-deportiva y si los sujetos practican bajo un entorno federado o por su cuenta. La muestra está compuesta por 1111 sujetos de edades comprendidas entre 15 y 64 años. La información ha sido recogida a través del Cuestionario para el Análisis de la Práctica de Actividades Físico-Deportivas (C.A.P.A.F.D. elaborado específicamente para esta investigación. Tras diversos análisis de independencia entre variables mediante la pruebas de c2 completada con análisis de residuos, entre otras, las conclusiones obtenidas apuntan que la percepción de competencia motriz es mayor en jóvenes y varones, disminuyendo progresivamente con la edad. Existe una relación directa entre la sensación de competencia motriz percibida y el nivel de práctica, siendo mayor en los practicantes federados y en los que realizan actividades físico-deportivas de carácter colectivo.

  15. The metapleural gland of ants

    DEFF Research Database (Denmark)

    Yek, Sze Huei; Mueller, Ulrich G

    2011-01-01

    The metapleural gland (MG) is a complex glandular structure unique to ants, suggesting a critical role in their origin and ecological success. We synthesize the current understanding of the adaptive function, morphology, evolutionary history, and chemical properties of the MG. Two functions......-compressible invagination of the integument and the secretion is thought to ooze out passively through the non-closable opening of the MG or is groomed off by the legs and applied to target surfaces. MG loss has occurred repeatedly among the ants, particularly in the subfamilies Formicinae and Myrmicinae, and the MG...... is more commonly absent in males than in workers. MG chemistry has been characterized mostly in derived ant lineages with unique biologies (e.g. leafcutter ants, fire ants), currently precluding any inferences about MG chemistry at the origin of the ants. A synthetic approach integrating functional...

  16. Hospitales seguros ante desastres

    OpenAIRE

    Celso Vladimir Bambaren Alatrista; María Del Socorro Alatrista Gutierrez

    2007-01-01

    Entre 1982 a 2005 se registraron daños en 1 143 establecimientos de salud en el Perú, generalmente debido a sismos, lluvias e inundaciones. Los daños en los servicios de salud producen la interrupción de la atención de la población y de los programas de salud, así como generan un gran gasto para la rehabilitación y reconstrucción. Por ello, se requiere proteger a los establecimientos de salud y desarrollar una política de hospitales seguros ante desastres que incluya medidas para prevenir o r...

  17. La vivienda ante emergencias

    Directory of Open Access Journals (Sweden)

    Arq. María Eugenia Gonzàlez Chipont

    2014-12-01

    Full Text Available Este trabajo propone analizar la evolución de la vivienda como respuesta ante emergencias desde principios del siglo XX hasta nuestros días. La secuencia de casos a analizar no sigue una cronología estricta sino que se organiza en función de un creciente grado de complejidad. Comienza con los aportes fundamentales de la vivienda mínima del movimiento moderno, con un fuerte acento en lo tecnológico, para ir profundizando, mientras avanzamos en el siglo, en los aspectos sociales de la arquitectura. Sin intentar oponer lo tecnológico y lo social, la estructura propuesta expresa un enriquecimiento de la cuestión técnica conforme se van ampliando sus objetivos sociales. Mientras los requerimientos tecnológicos como la inmediatez y la masividad de la respuesta, permanecen a lo largo del tiempo, la vivienda ante emergencias puede plantearse objetivos sociales cada vez más profundos. Los casos fueron elegidos a partir de autores renombrados de la Historia de la Arquitectura partiendo de ejemplos cercanos a la génesis del movimiento moderno para acercarnos cada vez más hacia el contexto actual de Latinoamérica. Se logra así un barrido geográfco pero principalmente cultural: desde las fuentes de la modernidad, bajo el paradigma sólido de la industrialización, hasta la inestabilidad de la ciudad posindustrial latinoamericana

  18. Credibilidad percibida del periodismo a través de la Internet: una visión desde la psicología del consumidor

    Directory of Open Access Journals (Sweden)

    Catalina Piñeros-Piza

    2011-01-01

    Full Text Available En el presente artículo se describen algunos criterios de credibilidad percibida que las personas usan cuando juzgan el periodismo en Internet. Estos criterios fueron comparados con los hallados en la literatura en contextos internacionales sobre credibilidad en el periodismo. Con una muestra de 166 participantes, quienes calificaron con una escala tipo Likert. Se exploró la credibilidad percibida que tienen los colombianos sobre el periodismo en Internet. Los resultados encontrados muestran que hay concordancia entre los criterios encontrados en la literatura y los usados por los lectores, no obstante, se halló una correlación negativa entre la dependencia al Internet (profesional/ académica y el nivel de credibilidad, al igual que entre las variaciones en el nivel de credibilidad con base en algunas variables socio-demográficas.

  19. Desarrollo de una herramienta para la evaluación de la calidad percibida en los centros de atención infantil temprana

    Directory of Open Access Journals (Sweden)

    Rita-Pilar Romero-Galisteo

    2015-01-01

    Full Text Available Este trabajo describe el desarrollo de un instrumento para evaluar la calidad percibida en los Centros de Atención Infantil Temprana (CAIT. La muestra estuvo constituida por 672 usuarios/as (508 mujeres y 162 hombres de entre 20 y 60 años, de 14 de los 16 CAIT que existían en la provincia de Málaga en el momento de la recogida de los datos. Los resultados del análisis factorial exploratorio evidencian una estructura de diez factores y unos índices de consistencia interna satisfactorios. Se concluye que la herramienta desarrollada, denominada Inventario de Calidad en los Centros de Atención Infantil Temprana (ICCAIT, constituye un instrumento con importantes evidencias de validez y fiabilidad que permite evaluar, especialmente en CAIT, la calidad percibida por parte de los/as usuarios/as de los mismos.

  20. Pest repellent properties of ant pheromones

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2012-01-01

    of ant pheromones may be sufficient to repel pest insects from ant territories. The study of ant semiochemicals is in its infancy, yet, evidence for their potential use in pest management is starting to build up. Pheromones from four of five tested ant species have been shown to deter herbivorous insect...... prey and competing ant species are also deterred by ant deposits, whereas ant symbionts may be attracted to them. Based on these promising initial findings, it seems advisable to further elucidate the signaling properties of ant pheromones and to test and develop their use in future pest management....

  1. La paradoja de Gibson y el dilema de la política monetaria

    Directory of Open Access Journals (Sweden)

    Luis Guillermo Vélez Alvarez

    1989-07-01

    Full Text Available El mecanismo mediante el cual las variaciones en la cantidad nominal de dinero transmiten su efecto sobre el sistema económico es central en la teoría de la política monetaria. La tendencia alcista del nivel de precios indicaría, en primer término, el ajuste de la economía a un exceso de oferta monetaria. Pero si se acompaña de tensiones alcistas en el mercado de fondos prestables, tal conclusión deja de ser evidente puesto que dichas tensiones pueden, por su parte, ser el reflejo de una insuficiencia de liquidez real. La política monetaria se ve así enfrentada a un dilema que no siempre es fácil de resolver. El artículo explora, con un aparato analítico simple, esta cuestión y muestra que no siempre resulta posible determinar inequívocamente la orientación que se le debe imprimir a la gestión monetaria.

  2. Los dilemas morales en la filosofía analítica

    Directory of Open Access Journals (Sweden)

    Peña, Lorenzo

    1991-04-01

    Full Text Available Not available.

    La filosofía analítica ha contribuido a esclarecer la cuestión de los dilemas morales, sobre todo gracias a la utilización de la lógica deóntica. Vienen aquí examinados los debates recientes en el seno de dicha corriente filosófica sobre los conflictos de obligaciones.. Se pone de manifiesto cuán difícil es admitir conflictos- morales sin pagar el precio de aceptar contradicciones verdaderas. Pero, a la inversa de lo habitual en quienes sostienen esa tesis, el artículo, en vez de pronunciarse en contra de que haya conflictos morales, trata de mostrar que sí los hay y, a tenor de ello, aboga por el reconocimiento de contradicciones verdaderas en la vida moral. Tales contradicciones pueden entenderse en el marco de una metafísica a la vez gradualista y aspectualista.

  3. Dilemas de autenticidad: la restauración de la Casa Freeman de Frank Lloyd Wright

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Chusid

    2015-06-01

    Full Text Available El artículo expone una breve descripción histórica ilustrativa del proceso de encargo, diseño y construcción de la casa con los bloques prefabricados característicos de la etapa californiana de Wright y de la vida posterior del edificio, centro neurálgico de la actividad de vanguardia artística de Los Ángeles, con sustanciales modificaciones llevadas a cabo por otros arquitectos afamados como Rudolph Schindler, Gregory Ain and John Lautner. En el texto se refleja no solo la tremenda complejidad técnica de restaurar esta casa erigida con un sistema constructivo sugerente pero tremendamente frágil y problemático y la dificultad añadida de su presencia en zona sísmica y los daños sufridos por el terremoto de Los Ángeles de 1994, sino también el dilema que surge a la hora de escoger eventualmente qué fase restaurar del edificio entre toda la estratificación de intervenciones de arquitectos estrella que caracteriza a este edificio.

  4. Dificultades y dilemas de la política de inmigración

    Directory of Open Access Journals (Sweden)

    Arango, Joaquín

    2005-06-01

    Full Text Available Immigration policies have never been as abundant and prominent as in our days, and yet immigration has never met with such an extended state of dissatisfaction. This article aims at explaining the underlying reasons for the above paradox, paying special attention to the many difficulties that immigration policies face nowadays and the challenges and dilemmas they are confronted with, particularly in the European Union region.

    Nunca, como en nuestros días, han sido tan abundantes y prominentes las políticas de inmigración, y nunca se ha vivido ésta con tanta y tan generalizada insatisfacción. El artículo pretenden explicar las razones que subyacen a tal paradoja, con especial atención a las dificultades a las que se enfrentan las políticas de inmigración en nuestros días y los dilemas que las atenazan, en particular en el ámbito de la Unión Europea.

  5. Performance Esportiva ou Performance Administrativa: O Dilema dos Gestores de um Clube de Futebol Brasileiro

    Directory of Open Access Journals (Sweden)

    Renan Bonamigo Tonial

    2017-02-01

    Full Text Available O mercado esportivo mundial assume um papel importante na economia de alguns países. No Brasil, a expressiva movimentação financeira posiciona o futebol como principal esporte desse mercado. Neste contexto está inserido o Grêmio Foot-Ball Porto Alegrense, um clube de futebol profissional com sede na cidade de Porto Alegre, no estado do Rio Grande do Sul. Os gestores responsáveis pelo clube encontram-se em um dilema relacionado as escolhas estratégicas, provocado pela baixa performance esportiva e administrativa do clube. Este caso de ensino, decorrente da consolidação de dados secundários, visando proporcionar a reflexão e promover a discussão sobre temas ligados ao planejamento estratégico, escolha da estratégia competitiva, processo decisório e identificação de perfil dos agentes de tomada de decisão. Desse modo, sugere-se a aplicação do caso nos cursos de graduação e pós-graduação, nas disciplinas de administração estratégica, administração mercadológica e administração esportiva.

  6. O julgamento moral de dilemas éticos em negociação

    Directory of Open Access Journals (Sweden)

    Filipe João Bera de Azevedo Sobral

    2009-10-01

    Full Text Available Os processos cognitivos da tomada de decisão ética têm sido objeto de estudo de diversas pesquisas interessadas em compreender o que motiva os executivos a tomar as decisões eticamente questionáveis. A negociação é uma das práticas empresariais mais interessantes para se estudar a honestidade e a ética, uma vez que é central a todas as interações humanas e é rica em dilemas éticos. Esta pesquisatem como objetivo analisar em que medida diferenças individuais em termos de prioridades do sistema de valores condicionam o julgamento moral de práticas negociais eticamente ambíguas. Usando um modelo de equações estruturais, as relações entre os sistemas de valores, a ideologia ética e o julgamento moral são avaliadas. Os resultados sugerem que as dimensões da individualidade humana analisadas exercem uma influência significativa na forma como os gestoresavaliam a moralidade de práticas negociais eticamente ambíguas. Os resultados podem ainda contribuir significativamente para melhorar a compreensão do processo de tomada de decisão ética.

  7. LOS DILEMAS DEL SEXO: (A-SEXUACIÓN, (IN-DIFERENCIA, (DES-IGUALDAD

    Directory of Open Access Journals (Sweden)

    Hans Saettele

    2011-01-01

    Full Text Available El artículo se propone explorar el campo de la diferencia sexual a través de la propuesta psicoanalítica. La reflexión parte del proceso de sexuación como inacabado y, por ello, permanentemente sometido a los avatares de la relación entre el saber y el sexo. De esta manera, la dimensión corporal deberá ser entendida no como producción "encarnada" de significaciones, sino como punto de quiebre del discurso. Esta reflexión arroja tres dilemas sobre los cuáles el sujeto sexuado y la cultura se posicionan constantemente: a Somos sexuados, pero nunca completamente, sobre todo por la inevitable sujeción al objeto causa de deseo, de ello resulta una (asexuación originaria; b La diferencia sexual entre lo masculino y lo femenino no encuentra su rasgo diferenciador originario, pues de éste nada puede saberse; y c De lo anterior se deduce que, al nivel de lo social, dicha indeterminación de la diferencia sexual y su sometimiento al objeto causa de deseo, trae como consecuencia un malestar con la igualdad.

  8. Dimensiones de personalidad, sentido de coherencia y salud percibida en pacientes con un síndrome fibromiálgico

    Directory of Open Access Journals (Sweden)

    José Besteiro

    2008-01-01

    Full Text Available Se evaluaron los rasgos de personalidad, el sentido de coherencia y la salud percibida en pacientes diagnosticadas con un síndrome fibromiálgico. Se utilizaron como controles pacientes diagnosticadas con artritis reumatoide y sujetos sanos. Se realizó un estudio ex post facto de tipo prospectivo. Tanto a las pacientes fibromiálgicas como a los controles se les aplicó el cuestionario de personalidad NEO PI-R, el OLQ de Antonovsky para evaluar el Sentido de Coherencia y el Cuestionario de Salud SF- 36 para evaluar la salud percibida. Las pacientes con fibromialgia obtuvieron puntuaciones más elevadas en neuroticismo y un sentido de coherencia más débil con niveles inferiores en las dimensiones de comprensibilidad y significado que las pacientes con artritis reumatoide y los controles sanos. Respecto a los índices de calidad de vida y a la salud percibida, las pacientes con fibromialgia muestran alteraciones en todas las dimensiones respecto a los grupos control. Los resultados obtenidos indican que las pacientes con fibromialgia presentan rasgos de personalidad y creencias de control que podrían actuar de forma patogénica favoreciendo la aparición de la enfermedad y alterando la percepción subjetiva de la misma.

  9. Inteligencia Emocional Percibida y el Bienestar Psicológico de Estudiantes Universitarios en Función del Nivel de Actividad Física

    Directory of Open Access Journals (Sweden)

    Eduardo José Fernández Ozcorta

    2015-01-01

    Full Text Available El objetivo principal fue analizar la inteligencia emocional percibida y el bienestar psicológico de los estudiantes universitarios en función de la práctica de actividad física. Se utilizó una muestra de 1008 estudiantes de una universidad pública andaluza con edades comprendidas entre los 17 y los 30 años, de los cuales 414 eran físicamente activos y 594 insuficientemente activos. Se emplearon diferentes cuestionarios para evaluar la actividad física habitual, la inteligencia emocional percibida y el bienestar psicológico. El análisis de correlaciones mostró que los constructos de claridad y reparación emocional correlacionaban positiva y significativamente con la autoestima y satisfacción con la vida. Se encontraron diferencias significativas entre los universitarios físicamente activos y los que no en todas las variables, salvo en la atención emocional. Los alumnos físicamente activos mostraron puntuaciones más elevadas en las variables que medían el bienestar (autoestima y satisfacción con la vida, en la claridad y reparación emocional. Los resultados se discuten en relación a la promoción de la actividad física como favorecedora del bienestar y la inteligencia emocional percibida en el alumnado universitario.

  10. Hospitales seguros ante desastres

    Directory of Open Access Journals (Sweden)

    Celso Vladimir Bambaren Alatrista

    2007-07-01

    Full Text Available Entre 1982 a 2005 se registraron daños en 1 143 establecimientos de salud en el Perú, generalmente debido a sismos, lluvias e inundaciones. Los daños en los servicios de salud producen la interrupción de la atención de la población y de los programas de salud, así como generan un gran gasto para la rehabilitación y reconstrucción. Por ello, se requiere proteger a los establecimientos de salud y desarrollar una política de hospitales seguros ante desastres que incluya medidas para prevenir o reducción de la vulnerabilidad estructural, no estructural y funcional en los nuevos establecimientos y en los existentes.(Rev Med Hered 2007;18:149-154.

  11. APLICACIÓN DE UN MODELO FACTORIAL CONFIRMATORIO PARA ENCONTRAR LOS FACTORES LATENTES QUE DETERMINAN LA CALIDAD DE VIDA PERCIBIDA

    Directory of Open Access Journals (Sweden)

    Valeria Gogni

    2016-08-01

    Full Text Available Tanto a nivel teórico como práctico, no existe un consenso acerca de qué se entiende por Calidad de Vida dado que este concepto posee un carácter complejo y multidimensional. En algunos casos, la satisfacción de vida se equipara con la Calidad de Vida y se refiere a la evaluación subjetiva que realiza un individuo del grado en el cual sus necesidades, deseos y metas más importantes se encuentran realizadas. Se asume que la satisfacción de vida total de una persona consiste en una amplia suma de satisfacciones en áreas particulares de la vida que son valoradas o juzgadas importantes, considerando que es un estado fluctuante y no un rasgo constante [6]. Campbell [4] plantea que la satisfacción de una persona en un área particular se integra con diversas componentes que cubren los distintos aspectos de la vida de una persona y que son evaluados subjetivamente por los individuos tanto en lo referido a la importancia en su contexto vital, como en relación a su felicidad o bienestar en dichos aspectos. En este trabajo, se evalúa la validez de este modelo teórico en la población de la ciudad de Buenos Aires, Argentina, mediante el ajuste de un modelo de Análisis Factorial Confirmatorio de segundo orden, aplicado a los ítems de una prueba que mide la calidad de vida percibida por los sujetos. El modelo se aplicó sobre una muestra de 1336 individuos de entre 18 y 65 años y los resultados del Análisis Factorial Confirmatorio muestran que la calidad de vida percibida por los sujetos está en estrecha relación con su nivel de satisfacción con una serie dimensiones o factores latentes: Ambiente o hábitat del sujeto, su Necesidad de trascendencia,las Redes sociales que lo contienen, y su Crecimiento Personal.

  12. Nivel de seguridad percibida por el paciente de hemodiálisis crónica

    Directory of Open Access Journals (Sweden)

    Verónica Martín Guerrero

    Full Text Available Introducción: Son múltiples las publicaciones que abordan los riesgos hospitalarios, sin embargo escasas las investigaciones que estudian eventos adversos en las unidades de diálisis desde la percepción de los pacientes. Objetivo: Evaluar el nivel de seguridad percibido por el paciente durante la sesión hemodiálisis. Material y métodos: Estudio descriptivo, donde participaron 44 pacientes. Al no encontrar ninguna escala validada se autodiseño una a partir de 3 escalas validadas que miden calidad, satisfacción y factores de estrés, elaborando un instrumento de 40 ítems. Resultados: Se realizó un análisis descriptivo y estratificado por edad y años en hemodiálisis. El 100% de los encuestados se sienten seguros durante la sesión de hemodiálisis. En relación con la calidad de los cuidados y la percepción de los mismos todos los ítems consiguen una puntuación superior al tres sobre cinco. En cuanto a la educación un 63% le gustaría recibir más educación aunque un 70% afirma saber actuar ante las complicaciones. En el listado de factores de estrés, obtienen puntuaciones mayores las complicaciones del acceso vascular, el tiempo conectado a la máquina, el transporte y temperatura de la sala. Conclusión: La calidad de los cuidados enfermeros percibidos obtiene una buena satisfacción. En cuanto a los factores estresantes creemos que se podría llevar a cabo intervenciones enfermeras para disminuirlos, realizando actividades educativas y lúdicas intradiálisis, todo ello para aumentar la seguridad, y la calidad de los cuidados.

  13. QGOLF-9: Escala para la evaluación de la calidad percibida en los clubes de golf

    Directory of Open Access Journals (Sweden)

    Virginia Serrano-G\\u00F3mez

    2013-01-01

    Full Text Available La evaluación de la calidad percibida ha cobrado una gran importancia en la gestión de las organizaciones de prestación de servicios. El objetivo de este trabajo es desarrollar una escala con propiedades psicométricas adecuadas, breve y de fácil aplicación que permita incorporar las percepciones de los usuarios a la gestión de los clubes de golf. Fueron entrevistados 403 usuarios de 4 clubes de golf con campos de 9 hoyos ubicados en Galicia (316 hombres y 87 mujeres, con edades comprendidas entre los 16 y 75 años (Media = 47.19; DE = 13.91. Para la recogida de datos se utilizó un cuestionario estructurado ad hoc que contaba con 25 elementos agrupados en 4 dimensiones. Fruto de un Análisis Factorial Exploratorio inicial y de un Análisis Factorial Confirmatorio posterior, ha sido posible obtener una escala final compuesta por tan solo 15 ítems agrupados en tres dimensiones. Dicha escala, además de ser breve y de fácil aplicación, posee un alto grado de validez de criterio (ya que explica el 72% del desempeño percibido del club y una elevada consistencia interna (con un α global de .91, lo que la convierte en una herramienta de notable interés aplicado.

  14. A cellular automata model for ant trails

    Indian Academy of Sciences (India)

    In this study, the unidirectional ant traffic flow with U-turn in an ant trail was inves- tigated using ... the literature, it was considered in the model that (i) ant colony consists of two kinds of ants, good- ... ponents without a central controller [8].

  15. ANT, tourism and situated globality

    DEFF Research Database (Denmark)

    Jóhannesson, Gunnar Thór; Ren, Carina Bregnholm; van der Duim, René

    2015-01-01

    viable descriptions of the collective condition of humans and more-than-humans in the Anthropocene. Also and moving past a merely descriptive approach, it discusses it as a useful tool to engage with the situated globalities which come into being through the socio-spatial coupling of tourism......In recent years Actor-network theory (ANT) has increasingly been felt in the field of tourism studies (Van der Duim, Ren, & Jóhannesson, 2012). An important implication of the meeting between ANT and tourism studies is the notion of tourism being described as a heterogeneous assemblage of what we...... are used to define as the separate spheres of nature and culture. This paper explores and relates the central tenets of ANT in tourism with regard to the concept of the Anthropocene. It presents the ANT approach as a flat and object-oriented ontology and methodology and explores its potentials to carve out...

  16. Ants Orase kultuurisõnum

    Index Scriptorium Estoniae

    2007-01-01

    26. jaanuaril toimub Tallinna Ülikooli Akadeemilises Raamatukogus seminar silmapaistvast Eesti teadlasest ja tõlkijast Ants Orasest. Esinevad kirjandusteadlased Tallinna Ülikoolist, Tartu Ülikoolist ja Eesti Kirjandusmuuseumist. Avaettekandeks on sõna Oklahoma Ülikooli professoril Vincent B. Leitchil, kes oli Ants Orase viimaseks juhendatavaks doktorandiks. Seminari korraldavad Tallinna Ülikool ja Eesti Kirjandusmuuseum. Vt ka Postimees, 26, jaan., lk. 18

  17. Dilemas morais de amor: Controle, conflitos e negociações em terreiros de umbanda

    Directory of Open Access Journals (Sweden)

    Kelson Gérison Oliveira Chaves

    2013-10-01

    Full Text Available O presente texto discute, a partir de uma pesquisa em Limoeiro do Norte, interior do Ceará, dilemas e conflitos morais vivenciados por pessoas que reali­zam os chamados trabalhos de amor, prática mágico­-religiosa muito difundida em terreiros de umbanda pelo Brasil. Colocados em prática para resolver inú­meros problemas amorosos, em alguns casos esses rituais podem visar a separação de um casal ou “for­çar” uma pessoa a se apaixonar por outra. É especial­mente nessas situações que surgem questões e, ao mesmo tempo, elaboram-se construções sobre o que seria certo ou errado fazer, donde emergem regras de controle moral e tentativas de negociação. The article Moral Dilemmas of Love: Control, Con­flicts and Negotiations In Umbanda Rituals draws on research in Limoeiro do Norte, inner-state Ceará, to discuss moral conflicts and dilemmas experienced by people who perform so-called love work, a magical-reli­gious practice widespread throughout umbanda gather­ings in Brazil. Carried out to resolve countless problems of an amorous nature, in some cases these rituals can be intended to separate a couple or “force” a person to fall in love with another. It is especially in these situations that issues arise and, at the same time, constructions develop regarding the right or wrong thing to do, whereby rules of moral control and attempts at negotiations emerge. Keywords: love, umbanda, magical religious practices, crack-cocaine; moral conflicts, love work

  18. Women’s Resistance Against Patriarchal System in Dilema Ijab Kabul Movie

    Directory of Open Access Journals (Sweden)

    Suhadi Suhadi

    2015-06-01

    Full Text Available This paper aims to interpret the resistance of women against patriarchal system in a documentary entitled "The Dilemma of Ijab Kabul". The focus of the analysis of the documentary film portraying the behavior of early marriage, becoming the first map in explaining what action the women were really in opposition, or vice versa. Concepts used in analyzing matches against the system patriarchal women in this documentary is the meaning of every concept of daily interactions in society, women's position and orientation in relation to men and women. Based on the findings of the analysis of this documentary is trying to persuade the audience to look at social phenomena wedding of a very different side than usual. Marriage shown a hegemony which then led to a form of resistance from the women. Resistance to patriarchal system which is done by women in the documentary can be seen from many phenomena of early marriage, divorce and re-marry.Tulisan ini bertujuan menafsirkan perlawanan perempuan terhadap sistem patrialkhal pada film dokumenter berjudul “Dilema Ijab Kabul”. Fokus dari analisis film dokumenter yang memotret perilaku pernikahan dini ini, menjadi peta awal dalam menjelaskan apakah tindakan para perempuan itu benar-benar sebagai perlawanan, atau sebaliknya. Konsep yang digunakan dalam menganalisis perlawanan perempuan terhadap sistem patrialkhal dalam film dokumenter ini yaitu konsep makna dari setiap interaksi keseharian dalam masyarakat, posisi perempuan, dan orientasi dalam hubungan laki-laki dan perempuan. Berdasarkan temuan hasil analisis adalah film dokumenter ini berusaha mengajak penonton untuk melihat fenomena sosial  pernikahan dari sisi yang sangat berbeda dari biasanya. Pernikahan ditampilkan sebuah hegemoni yang kemudian memunculkan suatu bentuk perlawanan dari para perempuan. Perlawanan terhadap sistem patriarkhal  yang dilakukan oleh perempuan dalam film dokumenter ini terlihat dari banyaknya fenomena pernikahan dini, cerai

  19. EL PAN VS. SALINAS O EL DILEMA DEL PRISIONERO: REFORMA INSTITUCIONAL Y COOPERACIÓN COMO ESTRATEGIA POLÍTICA

    Directory of Open Access Journals (Sweden)

    Alicia Gómez López

    2002-01-01

    Full Text Available Este artículo analiza, desde el punto de vista de la teoría de juegos, la estrategia que el Partido Acción Nacional desarrolló frente al gobierno de Carlos Salinas de Gortari luego de la turbulenta elección presidencial de 1988. El objetivo es demostrar que entre estos adversarios se estableció un tipo de juego cuyo modelo a menudo se utiliza para analizar procesos de transición: el Dilema del prisionero, con un desenlace, al menos en este caso, cooperativo. Como en todo dilema, en este juego la posibilidad de la cooperación implica la existencia de un escenario aceptable para ambos adversarios, pese a que en primer lugar se busquen resultados opuestos. En este caso, dicho escenario se relaciona con el hecho de que el objetivo central en la estrategia panista era lograr reformas institucionales que hicieran avanzar la transición mexicana, de manera que le fuera posible llegar al poder; un objetivo cuya materia —las reformas institucionales— resultaba perfectamente negociable para su adversario presidencial.

  20. Using Ants as bioindicators: Multiscale Issues in Ant Community Ecology

    Directory of Open Access Journals (Sweden)

    Alan Andersen

    1997-06-01

    Full Text Available Ecological patterns and processes are characteristically scale dependent, and research findings often cannot be translated easily from one scale to another. Conservation biology is challenged by a lack of congruence between the spatial scales of ecological research (typically involving small plots and land management (typically involving whole landscapes. Here, I discuss spatial scaling issues as they relate to an understanding of ant communities and, consequently, their use as bioindicators in land management. Our perceptions of fundamental patterns and processes in ant communities depend on scale: taxa that are behaviorally dominant at one scale are not necessarily so at others, functional groups recognized at one scale are often inappropriate for others, and the role of competition in community structure depends on the scale of analysis. Patterns of species richness and composition, and the ability of total richness to be estimated by surrogates, are all also scale dependent. Ant community ecology has a tradition of detailed studies in small plots, but the use of ants as bioindicators requires a predictive understanding of community structure and dynamics at a range of spatial scales. Such an appreciation of ant communities and their most effective use as bioindicators is best served by studies integrating results from plot-scale research with the broad-scale paradigms of biogeography, systematics, and evolutionary biology.

  1. Monoculture of leafcutter ant gardens.

    Directory of Open Access Journals (Sweden)

    Ulrich G Mueller

    2010-09-01

    Full Text Available Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens.Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens and extended lifespans (10-20 years. In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells, and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys.Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants, an analog of artificial selection.

  2. Practicas alimentarias de un grupo de estudiantes universitarios y las dificultades percibidas para realizar una alimentación saludable

    Directory of Open Access Journals (Sweden)

    Fabiola Becerra Bulla

    2015-07-01

    Full Text Available El presente artículo muestra los resultados de la investigación realizada con estudiantes de la Universidad Nacional de Colombia, sede Bogotá,  que cursaron la asignatura electiva “Estilos de vida saludable” entre el segundo semestre de 2010 y el primer semestre de 2012 y cuyo propósito fue determinar las prácticas alimentarias en los estudiantes e identificar las dificultades percibidas para realizar una alimentación saludable. El estudio fue de tipo observacional, descriptivo y de carácter transversal. Se realizó valoración antropométrica y se determinó el consumo de alimentos mediante un cuestionario de frecuencia de consumo de alimentos. Se encontró que aunque la prevalencia de estudiantes con estado nutricional normal fue alta, se presentó una prevalencia importante de exceso de peso, similar a lo reportado por otros estudios de la misma institución. En cuanto al consumo de alimentos, los resultados de este estudio como los de otras instituciones universitarias, en general reflejan inadecuados hábitos alimentarios con bajo consumo de frutas y verduras y alto consumo de golosinas y dentro de los principales motivos referidos para no realizar una alimentación saludable se reportaron los horarios de estudio, hábitos y costumbres y factores económicos. Estos hallazgos son concordantes con estudios realizados en otros contextos universitarios. De acuerdo a lo anterior, es importante que las universidades se conviertan en entidades promotoras de la salud, considerando que varios años de  la vida de los estudiantes transcurren en ellas y es necesario ofrecer posibilidades reales para que durante su permanencia modifiquen de manera positiva sus hábitos y comportamientos alimentarios.

  3. MOTIVACIONES Y BARRERAS PERCIBIDAS POR LAS MUJERES ESPAÑOLAS EN RELACIÓN A LA LACTANCIA MATERNA

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    N Marta Díaz-Gómez

    2016-01-01

    Full Text Available Fundamentos: La lactancia materna (LM por sus múltiples beneficios es la mejor intervención coste-efectiva en salud y debería constituir un objetivo prioritario de salud pública. El objetivo de este estudio fue conocer las motivaciones y barreras percibidas por las madres para iniciar o mantener la LM. Métodos: Estudio observacional transversal con 569 madres residentes en España en 2013, con hijos menores de 2 años que cumplimentaron un cuestionario estructurado. Muestreo bietápico, estratificado por comunidades autónomas y no probabilístico en cada comunidad. Resultados: El 88% de las madres daban LM o lo habían hecho. La edad media del destete fue 6.4 (DE 3.8 meses. El principal motivo para suspender la lactancia fue la sensación de baja producción de leche (29% seguido de la incorporación al trabajo (18%. El 67% de las madres indicaron que la decisión de amamantar la habían tomado ellas mismas. La dificultad para combinar la LM con la actividad laboral (43%, dar el pecho en lugares públicos (39%, los despertares nocturnos (62% y el menor aumento de peso del lactante (29% fueron los inconvenientes más referidos. La incorporación laboral fue el principal motivo para elegir la lactancia artificial (34% y para iniciar la lactancia parcial (39%. Conclusiones: La dificultad para combinar la LM con la actividad laboral, dar el pecho en lugares públicos, los despertares nocturnos y el menor aumento de peso del lactante, fueron los inconvenientes más referidos. La incorporación laboral fue el principal motivo para elegir la lactancia artificial y para iniciar la lactancia parcial.

  4. Determinantes multidimensionales en la calidad percibida del empleo. Evidencia empírica para España

    Directory of Open Access Journals (Sweden)

    Díaz-Chao, Ángel

    2015-04-01

    Full Text Available Through a representative sample of 8.755 employees in 2010, and using a structural equations model (SEM, this article analyzes empirically the multidimensional determinants (direct effects of the perceived work quality in Spain. The research concludes that the perceived work quality combines a broad set of explanatory dimensions that are linked with de workplace itself (intrinsic work quality, organization, access and inclusion, and compensations, but also with their environment and labor relations (social relations, work intensity, skills and training, and health and safety. Therefore, the public employment policies for ending the economic crisis should not only address the quality or workplace, but also meet the dimensions related to their environment and labor relations.A través de una muestra representativa para 8.755 empleados asalariados en 2010, y utilizando un sistema de ecuaciones estructurales, este artículo analiza empíricamente los determinantes multidimensionales (efectos directos de la calidad percibida del empleo en España. La investigación concluye que la calidad del empleo combina un amplio conjunto de dimensiones explicativas que están vinculadas con el propio puesto de trabajo (calidad intrínseca, organización, inclusión y acceso y compensación, pero también con su entorno y las relaciones laborales (relaciones sociales, intensidad del empleo, formación, y salud y seguridad en el trabajo. Por consiguiente, las políticas públicas de empleo para la salida de la crisis no solo deberían abordar la calidad del puesto de trabajo, sino también atender a las dimensiones vinculadas con su entorno y las relaciones laborales.

  5. Pest repelling properties of ant pheromones

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2014-01-01

    Ants control pests via predation and physical deterrence; however, ant communication is based on chemical cues which may serve as warning signals to potential prey and other intruders. The presence of ant pheromones may, thus, be sufficient to repel pests from ant territories. This mini-review sh......-review shows that four out of five tested ant species deposit pheromones that repel herbivorous prey from their host plants.......Ants control pests via predation and physical deterrence; however, ant communication is based on chemical cues which may serve as warning signals to potential prey and other intruders. The presence of ant pheromones may, thus, be sufficient to repel pests from ant territories. This mini...

  6. Gráficos de control multivariables aplicados a la estimación de la calidad percibida de la voz sobre ip

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    Leonardo Francisco Panes Martínez

    2007-07-01

    Full Text Available Con el desarrollo del protocolo de red IP se ha generado un crecimiento explosivo de Internet en los últimos diez o quince años, que ha llevado a la proliferación de múltiples servicios de comunicación, dada la naturaleza de este protocolo se hace necesario implementar mecanismos que permitan asegurar la calidad  de servicio a los usuarios finales. El presente artículo presenta un sistema de evaluación en línea efectiva en la vigilancia y medición de la calidad percibida de la voz sobre IP consistente en el tiempo. El modelo presentado combina el control estadístico de procesos y los métodos objetivos de estimación de la calidad percibida de voz. Para esto se ha implementado el grafico de control multivariable T_ de Hotteling y el método objetivo no intrusivo de estimación de la calidad percibida de voz “Modelo-E”. The development of the Internet Protocol ( IP it´s  generating an explosive growth of Internet and that have taken the proliferation of multiples services of communication. But  this protocol needs to implement mechanisms that allow to assure the quality of service to the end users. The present article presents a system of effective on-line evaluation in the surveillance and measurements  of the perceived quality of the voice on IP consistent in the time. The presented model combines the statistical control of processes and the objective methods of estimate of the perceived quality of voice. For this it has been implemented Multivariable Control Chart T_ de Hotteling and the perceived method for voice quality prediction to voice over IP.

  7. How ants drop out: ant abundance on tropical mountains.

    Science.gov (United States)

    Longino, John T; Branstetter, Michael G; Colwell, Robert K

    2014-01-01

    In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops.

  8. How ants drop out: ant abundance on tropical mountains.

    Directory of Open Access Journals (Sweden)

    John T Longino

    Full Text Available In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica and examined the impact of elevation (as a proxy for temperature and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops.

  9. Estudio de salud percibida y análisis del riesgo de desnutrición en un centro de atención integral de ancianos

    OpenAIRE

    Andía Muñoz, Virginia

    2017-01-01

    356 p. Se analizó el estado nutricional, la salud percibida, la dependencia, el estado cognitivo, y la dieta de un grupo de personas mayores institucionalizadas y externas atendidas para su alimentación. Los resultados obtenidos demostraron que el medio residencial y todo lo que conlleva de positivo, como el hecho de vivir acompañado o recibir asistencia socio-sanitaria diariamente, contribuía a sobrellevar mejor las limitaciones físicas propias de la edad, así como a mejorar la calidad de...

  10. Inteligencia Emocional Percibida y el Bienestar Psicológico de Estudiantes Universitarios en Función del Nivel de Actividad Física

    OpenAIRE

    Eduardo José Fernández Ozcorta; Bartolomé Jesús Almagro Torres; Pedro Sáenz - López Buñuel

    2015-01-01

    El objetivo principal fue analizar la inteligencia emocional percibida y el bienestar psicológico de los estudiantes universitarios en función de la práctica de actividad física. Se utilizó una muestra de 1008 estudiantes de una universidad pública andaluza con edades comprendidas entre los 17 y los 30 años, de los cuales 414 eran físicamente activos y 594 insuficientemente activos. Se emplearon diferentes cuestionarios para evaluar la actividad física habitual, la inteligencia emocional perc...

  11. FACTORES ASOCIADOS A LA CALIDAD DE ATENCIÓN PERCIBIDA POR EL USUARIO ATENDIDO EN CONSULTORIO DE PLANIFICACIÓN FAMILIAR. RED DE SALUD AZÁNGARO: 2010

    OpenAIRE

    CHARAJA AÑAZCO, LISBÉ

    2014-01-01

    CONCEPTO DE CALIDAD DE ATENCIÓN ASPECTOS DE LA CALIDAD SERVICIO DE CALIDAD AL CLIENTE NECESIDADES BÁSICAS DEL CLIENTE IMPORTANCIA DE LA GESTIÓN DE LA CALIDAD DEL SERVICIO CONCEPTO DE CALIDAD PERCIBIDA TRATO DIGNO ACCESIBILIDAD Y DISPONIBILIDAD SATISFACCIÓN O ACEPTABILIDAD COMPETENCIA TÉCNICA EL PROBLEMA DE LA CALIDAD EN LA SALUD PARÁMETROS DE CALIDAD EN LOS SERVICIOS DE SALUD DEFINICIÓN DE PERCEPCIÓN ASEGURAMIENTO DE LA CALIDAD LA GESTIÓN DE CALIDAD TOTAL RESULTADOS DE UN SISTEMA DE CALIDAD F...

  12. Síntomas de estrés postraumático en adolescentes expuestos a un terremoto: asociación con autoeficacia, magnitud percibida y miedo

    OpenAIRE

    Cristóbal Guerra; Patricio Cumsille; M. Loreto Martínez

    2014-01-01

    El objetivo de este estudio fue evaluar la relación entre la magnitud percibida, el miedo experimentado, las creencias de autoeficacia y los síntomas de estrés post-traumático en adolescentes. Se esperaba que las creencias de autoeficacia se asociaran con los síntomas de estrés post-traumático y que esta relación fuera mediada por el miedo. Se utilizaron datos que formaban parte de un estudio longitudinal sobre desarrollo normativo en la adolescencia que estaba en curso al momento de ocurrir ...

  13. O dilema do Estado ante a globalização e a economia informal: sonegação fiscal ou desemprego?

    Directory of Open Access Journals (Sweden)

    Cristianne Maria Barbosa Carneiro e Silva

    2002-01-01

    Full Text Available O crescimento da informalidade na economia, caracterizado, inclusive, pelo número cada vez maior de atividades econômicas que atuam à margem da economia oficial, coloca em cheque, além das questões sociais daí decorrentes, osistema estatal de fiscalização e de arrecadação tributária, gerando uma produção de riquezas que não é documentada nas estatísticas.Por outro lado, não se pode deixar de considerar a influência do processo de globalização no fortalecimento da economia informal. Parece-nos induvidoso que esse setor se utiliza dos mesmos mecanismos de transferências de mercadorias advindos da globalização, para fazer circular, em nível mundial, a maior parte dos produtos comercializados pela economia paralela. Com efeito, não se pode negar que o comércio informal é o meio pelo qual a indústria da pirataria dá vazão a sua produção. Desse modo, torna-se imprescindível aprofundar o debate acerca dos efeitos do processo de globalização sobre a economia informal, investigando o comportamento do Estado diante de duas conseqüências desse contexto: a sonegação fiscal e o desemprego.

  14. Dilemas del personal médico ante la violencia de pareja en México Dilemmas of healthcare providers towards domestic violence in Mexico

    Directory of Open Access Journals (Sweden)

    Cristina Herrera

    2006-11-01

    Full Text Available Se realizó un estudio cualitativo con 30 médicas/os y enfermeras/os del sector público en México, con el objetivo de conocer en profundidad las concepciones y prácticas frente a la violencia doméstica. Una encuesta reciente puso en evidencia que la mayoría de los profesionales de salud no conocen la Norma Oficial Mexicana que establece los criterios de atención de estos casos. Los resultados de las entrevistas evidencian que no existen diferencias entre los profesionales a nivel de la atención, y que además la atención resulta inadecuada. Por otra parte, hemos constatado la existencia de un repertorio de significados sociales en torno a la violencia que provienen de la tradición cultural y que dificultan una adecuada atención a este problema.This qualitative study of 30 physicians and nurses from the Mexican public health system aimed to understand their concepts and practices concerning domestic violence. A recent survey showed that most health professionals were unaware of the official criteria and procedures for dealing with cases of domestic violence. Our in-depth interviews failed to show substantial differences between professionals according to level of care, and that treatment was generally inadequate. We also observed a repertoire of ingrained social meanings among the medical staff concerning violence (derived from their own cultural traditions, hindering more effective responses to the problem.

  15. Ethical dilemmas experienced by nurses presented in nursing publications Dilemas éticos vivenciados por enfermeros y presentados en publicaciones de enfermería Dilemas éticos vivenciados por enfermeiros apresentados em publicações de enfermagem

    Directory of Open Access Journals (Sweden)

    Maria Adelane Alves Monteiro

    2008-12-01

    Full Text Available This systematic literature review used nursing studies about "ethics" published in the SCIELO database. The objective was to identify the ethical dilemmas of nursing, based on a literature review of nursing publications between 2002 and 2006. Forty publications were found, of which seventeen were selected. The analysis of the articles permitted the organization of the following categories: ethics, the health system and nursing practice; ethics and nursing teaching-learning; ethics and nursing care. We noticed that the authors attributed a multidimensional approach to ethical issues. However, we considered it necessary to pay closer attention to the ethical aspects involved in nursing practice. There is a clear need for further studies, showing new ethical dilemmas experienced by nurses, so that they can contribute to a change in attitude, with outcomes for professional practice.Se trata de una revisión sistemática de la literatura, realizada en artículos del área de la enfermería, contenidos en el banco de datos SCIELO, y que abordaron el tema "ética". El estudio tuvo como objetivo identificar los dilemas éticos de la enfermería a partir de una revisión de la literatura en publicaciones sobre esa área, en el período de 2002 a 2006. Se localizaron cuarenta publicaciones, de las cuales fueron seleccionadas diecisiete. El análisis de los artículos permitió la organización de las categorías en: ética, el sistema de salud y la práctica de enfermería, ética y la enseñanza-aprendizaje en la enfermería y, ética y el cuidado de enfermería. Se percibió que los autores realizaron, sobre las cuestiones éticas, un abordaje multidimensional, entretanto, se consideró necesario, en este estudio, dar mayor atención a los aspectos éticos que se encuentran frecuentemente en la práctica de enfermería. Quedó clara la necesidad de realizar otros estudios que pongan en evidencia nuevos dilemas éticos vivenciados por enfermeros, en el

  16. Internação por ordem judicial: dilemas éticos vivenciados por enfermeiros Internación por orden judicial: dilemas éticos vividos por enfermeros Hospitalization by court order: ethical dilemmas experienced by nurses

    Directory of Open Access Journals (Sweden)

    Mara Ambrosina de Oliveira Vargas

    2013-03-01

    Full Text Available Pesquisa qualitativa, cujo objetivo foi descrever as situações vivenciadas e os dilemas éticos dos enfermeiros no percurso de encaminhamento e recebimento, por ordem judicial, de pacientes com indicação de internação em Unidade de Terapia Intensiva (UTI. Foi efetivada entrevista parcialmente estruturada com 10 enfermeiros, que atuam em UTI e 10 que atuam em emergência de hospitais públicos e privados da região metropolitana de Porto Alegre, Brasil. Os dados foram submetidos à análise temática. Os resultados indicam que os enfermeiros vivenciam dilemas éticos consequentes aos problemas de superlotação das UTI e das emergências, da precária tecnologia especializada, da orientação quanto ao benefício concedido pela lei. Concluiu-se que é fundamental a participação dos enfermeiros em debates que possibilitem mapear as diferentes instâncias que têm promovido esta situação, muitas vezes caótica.Investigación cualitativa cuyo objetivo fue describir las situaciones vividas y los dilemas éticos de los enfermeros en el transcurso del envío y recibimiento por orden judicial de pacientes con indicación de internamiento en la Unidad de Cuidados Intensivos (UCI. Se realizó una entrevista parcialmente estructurada con 10 enfermeros que actuaban en la UCI y 10 que actuaban en Emergencias de hospitales públicos y privados de la región metropolitana de Porto Alegre, Brasil. Los datos fueron analizados según el Análisis Temático. Los resultados indican que los enfermeros experimentan dilemas éticos consiguientes problemas de hacinamiento en emergencia y UCI, especialista en tecnología pobre, la orientación en cuanto a los beneficios establecidos por la ley. Se concluye que es fundamental la participación de los enfermeros en debates que posibiliten mapear las diferentes instancias que han promovido esta situación muchas veces caótica.A qualitative study aimed at describing the situations experienced and the ethical

  17. Análisis de la relación entre familiaridad, seguridad percibida y confianza hacia la banca en internet

    Directory of Open Access Journals (Sweden)

    Eduardo Torres Moraga

    2011-01-01

    Full Text Available La confianza se ha convertido en un importante desafío para la banca en Internet. El hecho de que muchas personas aún no adopten Internet para realizar sus operaciones bancarias, se debe entre otras causas, a la poca confianza que aún existe hacia este sistema. Esta desconfianza, podría estar relacionada con la familiaridad y con el grado de seguridad que las personas perciben de este sistema bancario. El objetivo de este estudio es analizar el efecto que la familiaridad y la seguridad percibida tienen sobre la confianza hacia la banca en Internet. Las hipótesis planteadas, se contrastan a través de un modelo estructural, construido a partir de una serie de constructos fiables y válidos. Las principales conclusiones de este estudio, son que tanto la familiaridad como la seguridad percibida, tienen un efecto directo y positivo sobre la confianza. Al final del estudio, se presentan las implicaciones que estos resultados pudieran tener para la gestión de los factores determinantes de la confianza hacia la banca en Internet.

  18. Satisfacción y calidad percibida de afiliados al Sistema de Protección Social en Salud de México. Fundamentos metodológicos

    Directory of Open Access Journals (Sweden)

    Pedro J Saturno-Hernández

    2016-12-01

    Full Text Available Objetivo. Describir el marco conceptual, metodología de implementación y análisis de la Encuesta de Satisfacción de Usuarios del Sistema de Protección Social en Salud de México. Material y métodos. Se analizan los elemen­tos metodológicos de los estudios de 2013, 2014 y 2015, incluyendo el instrumento utilizado, muestreo y diseño del estudio, modelo conceptual y características e indicadores del análisis. Resultados. La encuesta captura información sobre calidad percibida y satisfacción. El muestreo tiene representación nacional y estatal. Se construyen y describen indicadores simples y compuestos (índice de satisfacción y porcentaje de problemas de calidad reportados. El análisis se completa mediante diagramas de Pareto, correlación entre indicadores y asociación con la satisfacción mediante modelos multivariados. Conclusiones. La medición de satisfacción y calidad percibida es un proceso complejo pero necesario para cumplir con la normativa y para identificar estrategias de mejora. La encuesta descrita presenta diseño y análisis rigurosos enfocados en su utilidad para mejorar.

  19. Meta-percepciones de competencia de terceros significativos, competencia percibida, motivación situacional y orientaciones de deportividad en jóvenes deportistas

    Directory of Open Access Journals (Sweden)

    Jos\\u00E9 Antonio Cecchini Estrada

    2014-01-01

    Full Text Available La finalidad de este estudio es comprobar un modelo teórico sobre la base de las aportaciones de Vallerand (1977 que incluya, como factores sociales, la meta-percepción de competencia de múltiples terceros significativos. Asimismo, el modelo recoge la relación entre la motivación auto-determinada situacional (SDI y las orientaciones de deportividad en deportes de contacto medio-alto. La muestra estuvo formada por 496 jugadores/as de fútbol y baloncesto, con edades comprendidas entre 11-17 años (M= 14.19, DE = 1.84. Los resultados mostraron que la meta-percepción de competencia del entrenador fue el principal predictor de la competencia percibida por los deportistas, seguida de la meta-percepción de los padres, del profesor de educación física y de los compañeros de equipo. En su conjunto muestran un valor predictivo elevado. La competencia percibida fue, a su vez, un predictor significativo de la SDI y, ésta, predijo sucesivamente las diferentes orientaciones hacia la deportividad de manera consistente.

  20. Estudio comparativo entre personalidad de marca ideal vs. percibida: aplicación a las compañías aéreas

    Directory of Open Access Journals (Sweden)

    María Walesska Schlesinger Díaz

    2008-06-01

    Full Text Available La personalidad de marca tiene un papel decisivo como elemento diferenciador y como estrategia de posicionamiento en la mente del consumidor. Este trabajo tiene como objetivo general comparar, según el modelo de Aaker (1997 en servicios, la personalidad de marca ideal vs. la percibida por los consumidores, específicamente en las compañías aéreas en el ámbito español. Empleando datos de encuesta, y tras la validación del modelo propuesto a través de un análisis factorial confirmatorio, se obtuvo el estudio comparativo. Los resultados indican que las dimensiones y los rasgos más importantes para los consumidores de este tipo de servicio son las menos percibidas por los clientes de las compañías aéreas. Se considera conveniente proponer a los responsables de compañías de servicio que se apoyen en los atributos intangibles ligados a la personalidad de marca a la hora de plantearse estrategias de posicionamiento, específicamente en atributos simbólicos y emotivos.

  1. Male parentage in army ants

    DEFF Research Database (Denmark)

    Kronauer, Daniel J C; Schöning, Caspar; Boomsma, Jacobus J

    2006-01-01

    of active research in insect sociobiology. Here we present microsatellite data for 176 males from eight colonies of the African army ant Dorylus (Anomma) molestus. Comparison with worker genotypes and inferred queen genotypes from the same colonies show that workers do not or at best very rarely reproduce...

  2. AVALIAÇÃO DO DESENVOLVIMENTO MORAL DE ADOLESCENTES EM RELAÇÃO A DILEMAS MORAIS DA VIDA DIÁRIA E DA PRÁTICA ESPORTIVA

    Directory of Open Access Journals (Sweden)

    José Luiz Lopes Vieira

    2008-07-01

    Full Text Available O principal propósito deste estudo foi identificar e comparar o nível de raciocínio moral de adolescentes participantes de esporte escolar. O estudo caracterizou-se como uma pesquisa descritiva. A população alvo constituiu-se de 31 (trinta e um atletas da cidade de Maringá, do sexo masculino, da faixa etária de quinze e dezessete anos, que participaram dos Jogos da Juventude do Paraná e, 43 (quarenta e três alunos não-atletas, da rede pública e particular do núcleo de educação de Maringá, totalizando 74 (setenta e quatro sujeitos. Como instrumento de medida utilizou-se um questionário, com dados de identificação e dois dilemas morais: o primeiro, de vida esportiva proposto por ROMANCE (1984 e, o segundo de vida diária citado por KOHLBERG (1958. Serviu como parâmetro de avaliação a teoria dos estágios de desenvolvimento moral de Kohlberg. Com base nos resultados, pudemos chegar às seguintes conclusões: os atletas apresentaram um raciocínio moral similar tanto no dilema de vida esportiva quanto no dilema de vida diária. Os não-atletas apresentaram um raciocínio moral diferente entre os dilemas da vida esportiva e da vida diária. Os atletas e os não-atletas demonstraram um raciocínio similar para o dilema da vida esportiva. Os atletas e os não-atletas demonstraram um raciocínio diferente com relação ao dilema da vida diária. O envolvimento esportivo e os objetivos formulados por professores de Educação Física, bem como, técnicos desportivos, parecem ser fatores que afetam o desenvolvimento moral dos educandos. Sugerem-se estudos similares com modificações quanto à idade e sexo, e sobre a aplicação de programas que objetivem o desenvolvimento moral, através da Educação Física e dos esportes.

  3. A cellular automata model for ant trails

    Indian Academy of Sciences (India)

    In this study, the unidirectional ant traffic flow with U-turn in an ant trail was investigated using one-dimensional cellular automata model. It is known that ants communicate with each other by dropping a chemical, called pheromone, on the substrate. Apart from the studies in the literature, it was considered in the model that ...

  4. Fungal Adaptations to Mutualistic Life with Ants

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus

    Fungus-growing ants (Attini) feed off a fungus they cultivate in a mutualistic symbiosis in underground chambers by providing it substrate they collect outside the colony. The tribe of Attine ants ranges from small colonies of the paleo- and basal Attine species with a few hundred workers that fo...... that the fungus evolved some incredible adaptations to a mutualistic life with the ants....

  5. Respuestas ante la confusión del consumidor por información ambigua: el caso de los cosméticos de una cadena de supermercados en España

    Directory of Open Access Journals (Sweden)

    José S. Clemente-Ricolfe

    2014-07-01

    Full Text Available Este estudio expuso y agrupó las reacciones de los consumidores ante la confusión generada por información ambigua para una marca de cosméticos de una cadena de supermercados. El método de recogida de la información fue la netnografía, usando para su análisis Componentes Principales Categóricos. Este trabajo supuso una aportación a la literatura sobre la confusión del consumidor porque la información se recogió a partir de comentarios on-line. La respuesta más citada fue la mala calidad percibida del producto. En relación al marco teórico, hay dos reacciones que no habían sido señaladas: las críticas a los medios de comunicación y la posible hostilidad de la competencia. La agrupación de las respuestas dadas se ha centrado fundamentalmente en dos aspectos: la imagen percibida de las empresas y la calidad de los productos.

  6. Afrontamiento ante la ansiedad pre-examen y autoeficacia académica en estudiantes de ciencias de la salud

    Directory of Open Access Journals (Sweden)

    Sergio Alexis Dominguez-Lara

    2018-01-01

    Full Text Available Resumen: Objetivo: Analizar la relación entre las estrategias de afrontamiento ante la situación pre-examen y la autoeficacia académica en una muestra de estudiantes de ciencias de la salud. Método: Se evaluó una muestra de 208 estudiantes (55,8% mujeres de entre 16 y 35 años (M = 20,37; DE = 3,155. Se usaron la Escala de afrontamiento ante la ansiedad e incertidumbre pre-examen y la Escala de autoeficacia percibida específica de situaciones académicas. La fiabilidad por consistencia fue calculada para cada subescala a través del coeficiente alfa. La relación entre variables fue analizada a través del coeficiente de correlación de Pearson. Resultados: Se hallaron correlaciones estadísticamente significativas entre la autoeficacia académica percibida y las estrategias Orientación a la tarea y Evitación, pero cercanas a cero con las estrategias de Búsqueda de apoyo. Conclusión: Las relaciones encontradas indican que las personas con mayor autoeficacia académica tienden a usar estrategias más vinculadas con el control de la situación previa al examen, que las destinadas a evitar o buscar apoyo. Abstract: Objective: The aim of the study was to analyse the relationship between coping with pre-examination anxiety and academic self-efficacy in health sciences college students. Method: The study was conducted on a sample of 208 students (55.8% women between ages 16 and 35 years old. The Coping with Pre-Exam Anxiety and Uncertainty and the Academic Situations Specific Perceived Self-efficacy Scale was used. The reliability was assessed by the coefficient alpha. The relationship between variables was assess using the Pearson correlation. Results: A significant relationship was found between perceived academic self-efficacy, and two strategies: Task-Oriented and Avoidance; but near to zero with seek-support strategy. Conclusion: The relationships found show that people with higher academic self-efficacy tend to use more

  7. Microsatellite Primers for Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  8. Microsatellite primers for fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  9. Un soldado de Menem en la encrucijada neoliberal. Los dilemas de un liderazgo sindical durante la década del ‘90

    Directory of Open Access Journals (Sweden)

    Guillermo José Colombo

    2015-07-01

    Full Text Available Este estudio tiene por objetivo analizar las respuestas de una conducción sindical durante la década del ‘90, enfrentada entonces al dilema de apoyar al partido de gobierno, en ese entonces el Partido Justicialista, el cual implementó un conjunto de políticas que afectaban las condiciones de trabajo de los representados por el gremio. A través de fuentes periodísticas, sindicales y entrevistas, se aborda una parte importante de la historia del Sindicato Obrero de la Industria del Pescado. Se indaga particularmente en la trayectoria político – ideológica de la conducción gremial, sus vínculos con el partido de gobierno, los movimientos internos surgidos en el sindicato y la tramitación de aquel dilema.

  10. Dilemas implicativos e ajustamento psicológico: um estudo com alunos recém-chegados à Universidade do Minho

    Directory of Open Access Journals (Sweden)

    Eugénia Fernandes

    2005-01-01

    Full Text Available En este artículo se presenta una investigación centrada en el ajuste psicológico y en la experiencia personal de alumnos recién llegados a la Universidad. El objetivo fue, por un lado, analizar las dificultades en el ajuste psicológico que manifiestan estos alumnos, tanto a través de la presencia de sintomatología psicopatológica como a través de las dificultades en la resolución de problemas vitales y, por otro, analizar si estas dimensiones se relacionan con la presencia de dilemas implicativos. En este estudio descriptivo transversal participaron 48 alumnos que asistían por primera vez a la Universidad de Minho. Los dilemas implicativos se identificaron por medio de la Rejilla de Repertorios de Kelly, los síntomas psicopatológicos se evaluaron con el SCL-90-R y las dificultades en la resolución de problemas se identificaron mediante el Inventario de Resolución de Problemas. Los resultados indican una correlación negativa y altamente significativa entre la presencia de sintomatología psicopatológica y las competencias de resolución de problemas. Además, los resultados sugieren que la relación entre la presencia de dilemas y la sintomatología psicopatológica, así como la relación entre presencia de dilemas y dificultades en la resolución de problemas, a pesar de no ser significativas, muestran la relación esperada. Se discuten las implicaciones de estos resultados para la comprensión de los desafíos que el ingreso en la Universidad supone en el ajuste psicológico de los estudiantes.

  11. Revolutionizing Remote Exploration with ANTS

    Science.gov (United States)

    Clark, P. E.; Rilee, M. L.; Curtis, S.; Truszkowski, W.

    2002-05-01

    We are developing the Autonomous Nano-Technology Swarm (ANTS) architecture based on an insect colony analogue for the cost-effective, efficient, systematic survey of remote or inaccessible areas with multiple object targets, including planetary surface, marine, airborne, and space environments. The mission context is the exploration in the 2020s of the most compelling remaining targets in the solar system: main belt asteroids. Main belt asteroids harbor important clues to Solar System origins and evolution which are central to NASA's goals in Space Science. Asteroids are smaller than planets, but their number is far greater, and their combined surface area likely dwarfs the Earth's. An asteroid survey will dramatically increase our understanding of the local resources available for the Human Exploration and Development of Space. During the mission composition, shape, gravity, and orbit parameters could be returned to Earth for perhaps several thousand asteroids. A survey of this area will rival the great explorations that encircled this globe, opened up the New World, and laid the groundwork for the progress and challenges of the last centuries. The ANTS architecture for a main belt survey consists of a swarm of as many as a thousand or more highly specialized pico-spacecraft that form teams to survey as many as one hundred asteroids a month. Multi-level autonomy is critical for ANTS and the objective of the proposed study is to work through the implications and constraints this entails. ANTS couples biologically inspired autonomic control for basic functions to higher level artificial intelligence that together enable individual spacecraft to operate as specialized, cooperative, social agents. This revolutionary approach postulates highly advanced, but familiar, components integrated and operated in a way that uniquely transcends any evolutionary extrapolation of existing trends and enables thousand-spacecraft missions.

  12. Ant-plant mutualism: a dietary by-product of a tropical ant's macronutrient requirements.

    Science.gov (United States)

    Arcila Hernández, Lina M; Sanders, Jon G; Miller, Gabriel A; Ravenscraft, Alison; Frederickson, Megan E

    2017-12-01

    Many arboreal ants depend on myrmecophytic plants for both food and shelter; in return, these ants defend their host plants against herbivores, which are often insects. Ant-plant and other mutualisms do not necessarily involve the exchange of costly rewards or services; they may instead result from by-product benefits, or positive outcomes that do not entail a cost for one or both partners. Here, we examined whether the plant-ant Allomerus octoarticulatus pays a short-term cost to defend their host plants against herbivores, or whether plant defense is a by-product benefit of ant foraging for insect prey. Because the food offered by ant-plants is usually nitrogen-poor, arboreal ants may balance their diets by consuming insect prey or associating with microbial symbionts to acquire nitrogen, potentially shifting the costs and benefits of plant defense for the ant partner. To determine the effect of ant diet on an ant-plant mutualism, we compared the behavior, morphology, fitness, stable isotope signatures, and gaster microbiomes of A. octoarticulatus ants nesting in Cordia nodosa trees maintained for nearly a year with or without insect herbivores. At the end of the experiment, ants from herbivore exclosures preferred protein-rich baits more than ants in the control (i.e., herbivores present) treatment. Furthermore, workers in the control treatment were heavier than in the herbivore-exclusion treatment, and worker mass predicted reproductive output, suggesting that foraging for insect prey directly increased ant colony fitness. The gaster microbiome of ants was not significantly affected by the herbivore exclusion treatment. We conclude that the defensive behavior of some phytoecious ants is a by-product of their need for external protein sources; thus, the consumption of insect herbivores by ants benefits both the ant colony and the host plant. © 2017 by the Ecological Society of America.

  13. Ecosystem services delivered by weaver ants

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    Weaver ants (Oecopgylla spp.) are increasingly being utilized as efficient biocontrol agents in a number of tropical tree crops, as they prey on pest insects and increase yields. However, recent studies and a review of the literature reveal that a number of other services may derive from the pres......Weaver ants (Oecopgylla spp.) are increasingly being utilized as efficient biocontrol agents in a number of tropical tree crops, as they prey on pest insects and increase yields. However, recent studies and a review of the literature reveal that a number of other services may derive from...... the presence of these ants. First of all, the chemical footprint left by the high density of ants in managed host trees may results in additional benefits. (i) Ant deposits may lead to improved fruit quality, e.g. increased sugar content, (ii) ant deposits may deter important pests (chemical deterrence) from...... crops, and lastly, (iii) ant waste products deposited ias anal spots contain urea that may be taken up by plant leaves and in this way fertilize ant-plants. On top of chemical services, weaver ants have been shown to reduce plant disease incidence via competitive exclusion of other ant species because...

  14. Roadside Survey of Ants on Oahu, Hawaii

    Science.gov (United States)

    Tong, Reina L.; Grace, J. Kenneth; Krushelnycky, Paul D.

    2018-01-01

    Hawaii is home to over 60 ant species, including five of the six most damaging invasive ants. Although there have been many surveys of ants in Hawaii, the last island-wide hand-collection survey of ants on Oahu was conducted in 1988–1994. In 2012, a timed hand-collection of ants was made at 44 sites in a systematic, roadside survey throughout Oahu. Ants were identified and species distribution in relation to elevation, precipitation and soil type was analyzed. To assess possible convenience sampling bias, 15 additional sites were sampled further from roads to compare with the samples near roads. Twenty-four species of ants were found and mapped; Pheidole megacephala (F.), Ochetellus glaber (Mayr), and Technomyrmex difficilis Forel were the most frequently encountered ants. For six ant species, a logistic regression was performed with elevation, average annual precipitation, and soil order as explanatory variables. O. glaber was found in areas with lower precipitation around Oahu. Paratrechina longicornis (Latrielle) and Tetramorium simillimum (Smith, F.) were found more often in lower elevations and in areas with the Mollisol soil order. Elevation, precipitation, and soil type were not significant sources of variation for P. megacephala, Plagiolepis alluaudi Emery, and T. difficilis. P. megacephala was associated with fewer mean numbers of ants where it occurred. Ant assemblages near and far from roads did not significantly differ. Many species of ants remain established on Oahu, and recent invaders are spreading throughout the island. Mapping ant distributions contributes to continued documentation and understanding of these pests. PMID:29439503

  15. Ant Larval Demand Reduces Aphid Colony Growth Rates in an Ant-Aphid Interaction

    Directory of Open Access Journals (Sweden)

    James M. Cook

    2012-02-01

    Full Text Available Ants often form mutualistic interactions with aphids, soliciting honeydew in return for protective services. Under certain circumstances, however, ants will prey upon aphids. In addition, in the presence of ants aphids may increase the quantity or quality of honeydew produced, which is costly. Through these mechanisms, ant attendance can reduce aphid colony growth rates. However, it is unknown whether demand from within the ant colony can affect the ant-aphid interaction. In a factorial experiment, we tested whether the presence of larvae in Lasius niger ant colonies affected the growth rate of Aphis fabae colonies. Other explanatory variables tested were the origin of ant colonies (two separate colonies were used and previous diet (sugar only or sugar and protein. We found that the presence of larvae in the ant colony significantly reduced the growth rate of aphid colonies. Previous diet and colony origin did not affect aphid colony growth rates. Our results suggest that ant colonies balance the flow of two separate resources from aphid colonies- renewable sugars or a protein-rich meal, depending on demand from ant larvae within the nest. Aphid payoffs from the ant-aphid interaction may change on a seasonal basis, as the demand from larvae within the ant colony waxes and wanes.

  16. Análisis Factorial Confirmatorio para medir las limitantes percibidas en el pregrado para el desarrollo de actividades de investigación

    Directory of Open Access Journals (Sweden)

    Deneb Elí Magaña Medina

    2017-01-01

    Full Text Available Introducción : El objetivo de este acercamiento fue validar a través de un análisis factorial confirmatorio un modelo de medida para determinar las limitantes percibidas para desarrollar interés por las actividades científica s o tecnológicas en el pregrado . Método : El estudio tuvo un enfoque cuantitativo con un diseño no experimental descriptivo y fue realizado en una Universidad Pública Estatal en el Sureste de México en donde s e seleccionaron 378 estudiantes de pregrado con más del 60% de créditos en su trayectoria escolar y que representaran todas las áreas del conocimiento. Se realizó un análisis factorial exploratorio y confirmatorio para determinar las propiedades psicométricas del instrumento . Resultados : El modelo propuesto corroboró a través del análisis factorial conf i rmatorio los valores de los principales indicadores de ajuste ( X 2 = 98.07, p = .00 1 ; CMIN/DF= 2.62; CFI=.95; GFI= .97, IFI= .95; RMSEA= .06 ; IC 90 [.03 - .09] . Asimismo, los resultados señalan que el 39.85% percibe alguna limitante importante de tipo personal y el 37.9% de conocimiento. Discusión o Conclusión : Los resultados permiten confirmar la sustentabilidad empírica para el modelo propuesto para medir las limitantes percibidas para la formación científica (LFC en estudiantes de pregrado de todas las áreas del conocimiento, pues los datos presentados muestran evidencia de un modelo factorial sustentable , siendo las limitantes personales las que afectan en mayor medida a los estudiantes encuestados.

  17. The distribution and diversity of insular ants

    DEFF Research Database (Denmark)

    Roura-Pascual, Núria; Sanders, Nate; Hui, Cang

    2016-01-01

    Aim: To examine the relationship between island characteristics (area, distance to the nearest continent, climate and human population size) and ant species richness, as well as the factors underlying global geographical clustering of native and exotic ant composition on islands. Location: One...... hundred and two islands from 20 island groups around the world. Methods: We used spatial linear models that consider the spatial structure of islands to examine patterns of ant species richness. We also performed modularity analyses to identify clusters of islands hosting a similar suite of species...... and constructed conditional inference trees to assess the characteristics of islands that explain the formation of these island-ant groups. Results: Island area was the best predictor of ant species richness. However, distance to the nearest continent was an important predictor of native ant species richness...

  18. Antígona y la muerte

    OpenAIRE

    Pérez Alcolea, Simona Micaela

    2012-01-01

    La ponencia analiza la muerte de Antígona en la obra de Sófocles. Se propone que su suicidio es un acto consciente de voluntad preanunciado a lo largo de toda la obra y no una medida desesperada. Con ese fin se exploran las posibles motivaciones de Antígona para poner fin a su vida. En el análisis se proponen tres respuestas (no necesariamente excluyentes): -Antígona responde a la ética homérica. Está en lucha con Creón, y su suicidio es su golpe de gracia al poder del rey. -Antígona...

  19. Ant-plant symbioses: Stalking the chuyachaqui.

    Science.gov (United States)

    Davidson, D W; McKey, D

    1993-09-01

    According to Quechua-speaking peoples, orchard-like stands ('Supay Chacras') of two Amazonian ant-plant species are cultivated by the devil, or 'Chuyachaqui'. These "devil gardens" offer extreme examples of specializations that have evolved repeatedly in ant-plant associations. Numerous investigations are beginning to disclose the identity of the Chuyachaqui - the forces behind evolutionary specialization in ant-plant symbioses. These developments have important implications for our understanding of modes of coevolution in symbiotic mutualism, remarkable convergent similarities in the form of ant-plant symbioses on different continents, and pronounced intercontinental differences in the diversity and taxonomic composition of associates. Copyright © 1993. Published by Elsevier Ltd.

  20. From Ant Trails to Pedestrian Dynamics

    Directory of Open Access Journals (Sweden)

    Andreas Schadschneider

    2003-01-01

    Full Text Available This paper presents a model for the simulation of pedestrian dynamics inspired by the behaviour of ants in ant trails. Ants communicate by producing a pheromone that can be smelled by other ants. In this model, pedestrians produce a virtual pheromone that influences the motion of others. In this way all interactions are strictly local, and so even large crowds can be simulated very efficiently. Nevertheless, the model is able to reproduce the collective effects observed empirically, eg the formation of lanes in counterflow. As an application, we reproduce a surprising result found in experiments of evacuation from an aircraft.

  1. Microorganisms transported by ants induce changes in floral nectar composition of an ant-pollinated plant.

    Science.gov (United States)

    de Vega, Clara; Herrera, Carlos M

    2013-04-01

    Interactions between plants and ants abound in nature and have significant consequences for ecosystem functioning. Recently, it has been suggested that nectar-foraging ants transport microorganisms to flowers; more specifically, they transport yeasts, which can potentially consume sugars and alter nectar composition. Therefore, ants could indirectly change nectar sugar profile, an important floral feature involved in the plant-pollinator mutualism. But this novel role for ants has never been tested. We here investigate the effects of nectarivorous ants and their associated yeasts on the floral nectar sugar composition of an ant-pollinated plant. Differences in the nectar sugar composition of ant-excluded and ant-visited flowers were examined in 278 samples by using high-performance liquid-chromatography. The importance of the genetic identity and density of ant-transported basidiomycetous and ascomycetous yeasts on the variation of nectar traits was also evaluated. Ant visitation had significant effects on nectar sugar composition. The nectar of ant-visited flowers contained significantly more fructose, more glucose, and less sucrose than the nectar of ant-excluded flowers, but these effects were context dependent. Nectar changes were correlated with the density of yeast cells in nectar. The magnitude of the effects of ant-transported ascomycetes was much higher than that of basiodiomycetes. Ants and their associated yeasts induce changes in nectar sugar traits, reducing the chemical control of the plant over this important floral trait. The potential relevance of this new role for ants as indirect nectar modifiers is a rich topic for future research into the ecology of ant-flower interactions.

  2. Pollination and facultative ant-association in the African leopard ...

    African Journals Online (AJOL)

    The role of extra-floral nectar appears to be recruitment of foraging ants to tend the flowers resulting in a facultative ant-association between the orchid and gregarious ants. Four different ant species were found to forage on A. africana's inflorescences. Ant-tended inflorescences suffered significantly less damage by insects.

  3. Michael Jackson antes del caos

    OpenAIRE

    Juan Luciano Nieves

    2015-01-01

    Michael Jackson es un buen ejemplo de cómo utilizar las relaciones públicas para realizar o manipular la imagen de un producto a través de los medios de comunicación. Este ensayo pretende analizar los eventos que tuvieron lugar antes de que el cantante fuera acusado de abuso sexual contra un menor. Dichos eventos formaron parte de un plan muy bien delineado para disminuir los efectos de la inminente crisis que se acercaba. Este trabajo combina la crítica retórica de temas de fantasía con teor...

  4. Viaje Antártico

    OpenAIRE

    Lasa, Gorka

    2017-01-01

    Ah, qué grandiosa sensación esta de poder caminar por los eternos hielos y dejar que mi vista se pierda en el horizonte crepuscular de esta desolada región! Aquellas solitarias islas, lamentos blancos en la distancia, aquellos azules glaciares llorando su neblina de frío y siglos. Al llamado lejano, mi alma se ve arrastrada por los vientos australes. Mítico ensueño que genera en mi imaginación el gran continente antártico. Belleza misteriosa e intimidante de la vastedad casi mágica que envuel...

  5. Foliar uptake of nitrogen from ant fecal droplets: an overlooked service to ant plants

    DEFF Research Database (Denmark)

    Pinkalski, Christian Alexander Stidsen; Jensen, Karl-Martin Vagn; Damgaard, Christian Frølund

    2018-01-01

    and subsequently deposited fecal droplets on the seedlings, coffee leaves showed increased levels of 15N and total N compared to control plants without ants. This was evident for both exposed leaves and leaves covered in plastic bags (i.e. not directly exposed to ants). Thus, N from ant excretions was absorbed...

  6. Entre la justicia indígena y la ordinaria: dilema aún por resolver

    Directory of Open Access Journals (Sweden)

    Filipo Ernesto Burgos Guzmán

    2008-12-01

    Full Text Available La Constitución de 1991 propició un cambio en las relaciones con las minorías étnicas en general y en aras de su protección existe el reconocimiento de derechos colectivos y fundamentales de grupo. Dentro de ellos, uno trascendental: la jurisdicción indígena. Hoy, 17 años después de la entrada en vigencia de la nueva Constitución y de haberse reconocido a los indígenas su propias leyes y jueces, su sentido y razón de ser se ha ido aclarando y ampliando por la jurisprudencia constitucional, al abrigo del tratado internacional 169 de 1989 de la oit y la decisiones de la Corte Interamericana de Justicia. No obstante, cuando revisamos los conflictos de competencias suscitados, encontramos que cuando se resuelve u otorga competencia a la justicia ordinaria o indígena, en casos concretos llevados ante el Consejo Superior de la Judicatura, la visión de este tribunal no es acorde con el avance constitucional y en ocasiones parecería estar bajo el amparo de la Constitución monocultural de 1886.

  7. Entre la justicia indígena y la ordinaria: dilema aún por resolver

    Directory of Open Access Journals (Sweden)

    Filipo Ernesto Burgos Guzmán

    2008-01-01

    Full Text Available La Constitución de 1991 propició un cambio en las relaciones con las minorías étnicas en general y en aras de su protección existe el reconocimiento de derechos colectivos y fundamentales de grupo. Dentro de ellos, uno trascendental: la jurisdicción indígena. Hoy, 17 años después de la entrada en vigencia de la nueva Constitución y de haberse reconocido a los indígenas su propias leyes y jueces, su sentido y razón de ser se ha ido aclarando y ampliando por la jurisprudencia constitucional, al abrigo del tratado internacional 169 de 1989 de la oit y la decisiones de la Corte Interamericana de Justicia. No obstante, cuando revisamos los conflictos de competencias suscitados, encontramos que cuando se resuelve u otorga competencia a la justicia ordinaria o indígena, en casos concretos llevados ante el Consejo Superior de la Judicatura, la visión de este tribunal no es acorde con el avance constitucional y en ocasiones parecería estar bajo el amparo de la Constitución monocultural de 1886.

  8. The evolution of genome size in ants

    Directory of Open Access Journals (Sweden)

    Spagna Joseph C

    2008-02-01

    Full Text Available Abstract Background Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta, and the two published estimates for this species differ by 146.7 Mb (0.15 pg. Results Here, we report the genome size for 40 species of ants distributed across 10 of the 20 currently recognized subfamilies, thus making Formicidae the 4th most surveyed insect family and elevating the Hymenoptera to the 5th most surveyed insect order. Our analysis spans much of the ant phylogeny, from the less derived Amblyoponinae and Ponerinae to the more derived Myrmicinae, Formicinae and Dolichoderinae. We include a number of interesting and important taxa, including the invasive Argentine ant (Linepithema humile, Neotropical army ants (genera Eciton and Labidus, trapjaw ants (Odontomachus, fungus-growing ants (Apterostigma, Atta and Sericomyrmex, harvester ants (Messor, Pheidole and Pogonomyrmex, carpenter ants (Camponotus, a fire ant (Solenopsis, and a bulldog ant (Myrmecia. Our results show that ants possess small genomes relative to most other insects, yet genome size varies three-fold across this insect family. Moreover, our data suggest that two whole-genome duplications may have occurred in the ancestors of the modern Ectatomma and Apterostigma. Although some previous studies of other taxa have revealed a relationship between genome size and body size, our phylogenetically-controlled analysis of this correlation did not reveal a significant relationship. Conclusion This is the first analysis of genome size in ants (Formicidae and the first across multiple species of social insects. We show that genome size is a variable trait that can evolve gradually over long time spans, as well as rapidly, through processes that may

  9. Hybrid chaotic ant swarm optimization

    International Nuclear Information System (INIS)

    Li Yuying; Wen Qiaoyan; Li Lixiang; Peng Haipeng

    2009-01-01

    Chaotic ant swarm optimization (CASO) is a powerful chaos search algorithm that is used to find the global optimum solution in search space. However, the CASO algorithm has some disadvantages, such as lower solution precision and longer computational time, when solving complex optimization problems. To resolve these problems, an improved CASO, called hybrid chaotic swarm optimization (HCASO), is proposed in this paper. The new algorithm introduces preselection operator and discrete recombination operator into the CASO; meanwhile it replaces the best position found by own and its neighbors' ants with the best position found by preselection operator and discrete recombination operator in evolution equation. Through testing five benchmark functions with large dimensionality, the experimental results show the new method enhances the solution accuracy and stability greatly, as well as reduces the computational time and computer memory significantly when compared to the CASO. In addition, we observe the results can become better with swarm size increasing from the sensitivity study to swarm size. And we gain some relations between problem dimensions and swam size according to scalability study.

  10. Administración de los problemas financieros en los bancos. Dilema entre los riesgos de liquidez y solvencia

    Directory of Open Access Journals (Sweden)

    Spiros Bougheas

    2008-01-01

    Full Text Available Elaboramos un marco microeconómico de la banca para analizar cómo influyen las decisiones de administración de la liquidez en la disponibilidad de liquidez para los depositantes, la viabilidad del proceso de transformación de activos y la solvencia de las empresas bancarias. En particular, nos centramos en la manera como la asignación óptima de los depósitos entre las reservas y una cartera de inversión riesgosa, hecha por un banco que maximiza sus ganancias, afecta la probabilidad de cada tipo de quiebra bancaria en un ambiente en el que hay incertidumbre en ambas partes de su balanza general. Nuestra meta principal es examinar los dilemas de administración entre los riegos provenientes de la incertidumbre en el comportamiento de los depositantes y los provenientes de los activos asociados al riesgo inherente a su cartera de inversión. Distinguiendo entre la iliquidez y la insolvencia como causas de las quiebras bancarias, intentamos entender cómo afecta la interacción entre estos dos tipos de riesgo al proceso de transformación de activos del banco.

  11. Altas habilidades/superdotação: mitos e dilemas docentes na indicação para o atendimento

    Directory of Open Access Journals (Sweden)

    Sonia Maria Lourenço de Azevedo

    Full Text Available O baixo quantitativo de indicação de alunos com altas habilidades/superdotação apontado pelos professores de um Município da periferia do Rio de Janeiro motivou a investigação das possíveis dificuldades encontradas pelos professores nesse processo. Os sujeitos desta pesquisa são 52 professores divididos em dois grupos: 26 professores que indicaram alunos para o programa de alunos com altas habilidades/ superdotação da Secretaria Municipal de Educação desse Município (grupo 1, e 26 professores que não indicaram alunos (grupo 2. Os fatores utilizados nesta pesquisa foram: (a perfil sociodemográfico dos respondentes; (b levantamento de possíveis elementos da representação social desse professor por meio dos termos indutores: altas habilidades/superdotação e educação especial; (c três dilemas baseados na teoria de julgamento moral e nos mitos referentes a altas habilidades/superdotação. conclui-se que, em ambos os grupos, há fortes indícios de que os mitos acerca das altas habilidades/superdotação influenciam a indicação/não indicação desses alunos, e que esses mitos devem ser discutidos junto aos professores de modo a facilitar a indicação

  12. Incertidumbre y complejidad: reflexiones acerca de los retos y dilemas de la pedagogía ceontemporánea

    Directory of Open Access Journals (Sweden)

    Rodrigo Campos Hernández

    2008-01-01

    Full Text Available Este artículo desarrolla una reflexión acerca de los retos y dilemas que suponen para la pedagogía contemporánea la presencia de la incertidumbre y de la complejidad como condiciones en que debe desenvolverse la actividad científica en la socio-cultura actual. Interesa destacar cómo, frente a estas realidades inciertas y complejas, se impone la necesidad de revisar sustancialmente el quehacer pedagógico para responder a las múltiples demandas del nuevo entorno que supone la llamada sociedad del conocimiento. El artículo no pretende agotar el tema, sino, por el contrario, abrir espacios de discusión que contribuyan con el proceso de renovación pedagógica tan necesaria en estos momentos para la sociedad costarricense. En este sentido, nuestra principal propuesta parte de la tesis de Morin acerca de que lo que está en juego en este momento no es una reforma programática de la pedagogía, que podría dar origen a nuevos planes de estudio, sino una reforma paradigmática que reconozca el carácter sistémico, transdisciplinar y complejo del conocimiento. Ya que sólo desde esta perspectiva será posible diseñar, desarrollar e innovar el quehacer curricular y didáctico en nuestro sistema educativo.

  13. The Biochemical Toxin Arsenal from Ant Venoms

    Directory of Open Access Journals (Sweden)

    Axel Touchard

    2016-01-01

    Full Text Available Ants (Formicidae represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents.

  14. Hey! A Fire Ant Stung Me!

    Science.gov (United States)

    ... Videos for Educators Search English Español Hey! A Fire Ant Stung Me! KidsHealth / For Kids / Hey! A ... Me picó una roja o colorada! What's a Fire Ant? There are many different types of fire ...

  15. The Biochemical Toxin Arsenal from Ant Venoms

    Science.gov (United States)

    Touchard, Axel; Aili, Samira R.; Fox, Eduardo Gonçalves Paterson; Escoubas, Pierre; Orivel, Jérôme; Nicholson, Graham M.; Dejean, Alain

    2016-01-01

    Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents. PMID:26805882

  16. Ant aggression and evolutionary stability in plant-ant and plant-pollinator mutualistic interactions.

    Science.gov (United States)

    Oña, L; Lachmann, M

    2011-03-01

    Mutualistic partners derive a benefit from their interaction, but this benefit can come at a cost. This is the case for plant-ant and plant-pollinator mutualistic associations. In exchange for protection from herbivores provided by the resident ants, plants supply various kinds of resources or nests to the ants. Most ant-myrmecophyte mutualisms are horizontally transmitted, and therefore, partners share an interest in growth but not in reproduction. This lack of alignment in fitness interests between plants and ants drives a conflict between them: ants can attack pollinators that cross-fertilize the host plants. Using a mathematical model, we define a threshold in ant aggressiveness determining pollinator survival or elimination on the host plant. In our model we observed that, all else being equal, facultative interactions result in pollinator extinction for lower levels of ant aggressiveness than obligatory interactions. We propose that the capacity to discriminate pollinators from herbivores should not often evolve in ants, and when it does it will be when the plants exhibit limited dispersal in an environment that is not seed saturated so that each seed produced can effectively generate a new offspring or if ants acquire an extra benefit from pollination (e.g. if ants eat fruit). We suggest specific mutualism examples where these hypotheses can be tested empirically. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  17. Calidad de atención percibida y satisfacción de los usuarios externos del servicio de Odontología en el Centro de Salud, Los Olivos, 2015

    OpenAIRE

    Ramírez Auris, Nelly; Álvarez Ramírez, Carmen

    2015-01-01

    Este estudio se denominó “Calidad de atención percibida y satisfacción de los usuarios externo del servicio de Odontología en el C.S Los Olivos,2015”, fue desarrollado para alcanzar el grado académico de Magister en Salud con Mención en Gestión en los Servicios de Salud, siendo la problemática concebida en la siguiente formulación ¿Qué relación existe entre calidad de atención percibida y satisfacción de los usuarios externos en el Servicio de Odontología del Centro de Salud Lo...

  18. AntStar: Enhancing Optimization Problems by Integrating an Ant System and A⁎ Algorithm

    Directory of Open Access Journals (Sweden)

    Mohammed Faisal

    2016-01-01

    Full Text Available Recently, nature-inspired techniques have become valuable to many intelligent systems in different fields of technology and science. Among these techniques, Ant Systems (AS have become a valuable technique for intelligent systems in different fields. AS is a computational system inspired by the foraging behavior of ants and intended to solve practical optimization problems. In this paper, we introduce the AntStar algorithm, which is swarm intelligence based. AntStar enhances the optimization and performance of an AS by integrating the AS and A⁎ algorithm. Applying the AntStar algorithm to the single-source shortest-path problem has been done to ensure the efficiency of the proposed AntStar algorithm. The experimental result of the proposed algorithm illustrated the robustness and accuracy of the AntStar algorithm.

  19. Cryptococcus neoformans carried by Odontomachus bauri ants

    Directory of Open Access Journals (Sweden)

    Mariana Santos de Jesus

    2012-06-01

    Full Text Available Cryptococcus neoformans is the most common causative agent of cryptococcosis worldwide. Although this fungus has been isolated from a variety of organic substrates, several studies suggest that hollow trees constitute an important natural niche for C. neoformans. A previously surveyed hollow of a living pink shower tree (Cassia grandis positive for C. neoformans in the city of Rio de Janeiro, Brazil, was chosen for further investigation. Odontomachus bauri ants (trap-jaw ants found inside the hollow were collected for evaluation as possible carriers of Cryptococcus spp. Two out of 10 ants were found to carry phenoloxidase-positive colonies identified as C. neoformans molecular types VNI and VNII. The ants may have acted as a mechanical vector of C. neoformans and possibly contributed to the dispersal of the fungi from one substrate to another. To the best of our knowledge, this is the first report on the association of C. neoformans with ants of the genus Odontomachus.

  20. Recurrence analysis of ant activity patterns.

    Directory of Open Access Journals (Sweden)

    Felipe Marcel Neves

    Full Text Available In this study, we used recurrence quantification analysis (RQA and recurrence plots (RPs to compare the movement activity of individual workers of three ant species, as well as a gregarious beetle species. RQA and RPs quantify the number and duration of recurrences of a dynamical system, including a detailed quantification of signals that could be stochastic, deterministic, or both. First, we found substantial differences between the activity dynamics of beetles and ants, with the results suggesting that the beetles have quasi-periodic dynamics and the ants do not. Second, workers from different ant species varied with respect to their dynamics, presenting degrees of predictability as well as stochastic signals. Finally, differences were found among minor and major caste of the same (dimorphic ant species. Our results underscore the potential of RQA and RPs in the analysis of complex behavioral patterns, as well as in general inferences on animal behavior and other biological phenomena.

  1. Ants defend aphids against lethal disease

    Science.gov (United States)

    Nielsen, Charlotte; Agrawal, Anurag A.; Hajek, Ann E.

    2010-01-01

    Social insects defend their own colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural enemies. Here we report that Formica podzolica ants tending milkweed aphids, Aphis asclepiadis, protect aphid colonies from lethal fungal infections caused by an obligate aphid pathogen, Pandora neoaphidis. In field experiments, bodies of fungal-killed aphids were quickly removed from ant-tended aphid colonies. Ant workers were also able to detect infective conidia on the cuticle of living aphids and responded by either removing or grooming these aphids. Our results extend the long-standing view of ants as mutualists and protectors of aphids by demonstrating focused sanitizing and quarantining behaviour that may lead to reduced disease transmission in aphid colonies. PMID:19923138

  2. Persistence of pollination mutualisms in the presence of ants.

    Science.gov (United States)

    Wang, Yuanshi; Wang, Shikun

    2015-01-01

    This paper considers plant-pollinator-ant systems in which the plant-pollinator interaction is mutualistic but ants have both positive and negative effects on plants. The ants also interfere with pollinators by preventing them from accessing plants. While a Beddington-DeAngelis (BD) formula can describe the plant-pollinator interaction, the formula is extended in this paper to characterize the pollination mutualism under the ant interference. Then, a plant-pollinator-ant system with the extended BD functional response is discussed, and global dynamics of the model demonstrate the mechanisms by which pollination mutualism can persist in the presence of ants. When the ant interference is strong, it can result in extinction of pollinators. Moreover, if the ants depend on pollination mutualism for survival, the strong interference could drive pollinators into extinction, which consequently lead to extinction of the ants themselves. When the ant interference is weak, a cooperation between plant-ant and plant-pollinator mutualisms could occur, which promotes survival of both ants and pollinators, especially in the case that ants (respectively, pollinators) cannot survive in the absence of pollinators (respectively, ants). Even when the level of ant interference remains invariant, varying ants' negative effect on plants can result in survival/extinction of both ants and pollinators. Therefore, our results provide an explanation for the persistence of pollination mutualism when there exist ants.

  3. Michael Jackson antes del caos

    Directory of Open Access Journals (Sweden)

    Juan Luciano Nieves

    2015-01-01

    Full Text Available Michael Jackson es un buen ejemplo de cómo utilizar las relaciones públicas para realizar o manipular la imagen de un producto a través de los medios de comunicación. Este ensayo pretende analizar los eventos que tuvieron lugar antes de que el cantante fuera acusado de abuso sexual contra un menor. Dichos eventos formaron parte de un plan muy bien delineado para disminuir los efectos de la inminente crisis que se acercaba. Este trabajo combina la crítica retórica de temas de fantasía con teoría de comunicación.

  4. Individual Recognition in Ant Queens

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Heinze, Jürgen

    2005-01-01

    Personal relationships are the cornerstone of vertebrate societies, but insect societies are either too large for individual recognition, or their members were assumed to lack the necessary cognitive abilities 1 and 2 . This paradigm has been challenged by the recent discovery that paper wasps...... recognize each other's unique facial color patterns [3] . Individual recognition is advantageous when dominance hierarchies control the partitioning of work and reproduction 2 and 4 . Here, we show that unrelated founding queens of the ant Pachycondyla villosa use chemical cues to recognize each other...... individually. Aggression was significantly lower in pairs of queens that had previously interacted than in pairs with similar social history but no experience with one another. Moreover, subordinates discriminated familiar and unfamiliar dominants in choice experiments in which physical contact, but not odor...

  5. FDTD-ANT User Manual

    Science.gov (United States)

    Zimmerman, Martin L.

    1995-01-01

    This manual explains the theory and operation of the finite-difference time domain code FDTD-ANT developed by Analex Corporation at the NASA Lewis Research Center in Cleveland, Ohio. This code can be used for solving electromagnetic problems that are electrically small or medium (on the order of 1 to 50 cubic wavelengths). Calculated parameters include transmission line impedance, relative effective permittivity, antenna input impedance, and far-field patterns in both the time and frequency domains. The maximum problem size may be adjusted according to the computer used. This code has been run on the DEC VAX and 486 PC's and on workstations such as the Sun Sparc and the IBM RS/6000.

  6. Calidad de vida percibida en adultos mayores de la provincia de Matanzas Quality of life perceived in elderlies from Matanzas province

    Directory of Open Access Journals (Sweden)

    Dianelis Dueñas González

    2009-09-01

    Full Text Available INTRODUCCIÓN: el estudio de la calidad de vida es de gran utilidad en las poblaciones envejecidas, en tanto constituye un trazador cualitativo de la salud en este segmento poblacional, aquejado con frecuencia de discapacidades que limitan su desempeño social. OBJETIVO: describir el comportamiento de la calidad de vida percibida en general, y su relación con variables seleccionadas en adultos mayores de la provincia de Matanzas. MÉTODOS: se realizó un estudio descriptivo de corte transversal, en un universo de 108 559 adultos mayores, de los que se seleccionó una muestra de 741, por muestreo estratificado polietápico. Se aplicaron el Examen Mínimo del Estado Mental y la Escala para la Evaluación de la Calidad de Vida Percibida. Se calcularon frecuencias absolutas y porcentajes, y se aplicó la prueba de homogeneidad y otras específicas como Bartholomew, Ridit Analysis y x² para la regresión. El procesamiento se realizó con SPSS versión 11,5, y Epidat 3,1. Los resultados de presentan en tablas. RESULTADOS: predominio de calidad de vida percibida baja, que constituyó el 43,3 % de la muestra investigada. Hubo diferencias importantes en el comportamiento de la calidad de vida por edad y escolaridad, con tendencia a empeorar en la medida que se incrementa la edad (p=0,000 y disminuye la escolaridad (p=0,000. No hubo diferencias por sexo (p=0,343 ni por estado conyugal (p=0,123. CONCLUSIONES: el predominio de baja calidad de vida en la población investigada evidencia la necesidad de continuar el estudio sobre este constructo, para lo cual resulta de interés su relación con la edad y la escolaridad.INTRODUCTION: quality of life study is very useful in aging populations, since it is a qualitative marker of health in this segment of population, frequently affected by disabling events limiting its social performance. OBJECTIVE: to describe quality of life behavior in general, and its relation with selected variables in elderlies from

  7. Dilema entre los paradigmas cualitativo y cuantitativo de la investigación.Necesidad de una visión distinta

    OpenAIRE

    Behar Rivero, Daniel Salomón

    2011-01-01

    Se reflexionó sobre la necesidad de analizar el dilema relacionado con la polarización de la discusión, en torno a la potencialidad de los enfoques cuantitativo y cualitativo, donde se destacó que el empleo de ambos procedimientos ayuda a corregir los errores propios de cada paradigma. También se enfatizó en que esta visión facilitará los cambios necesarios que deben operarse para la integración de la práctica metodológica del quehacer científico. Some thought was given to the necessity fo...

  8. Fronteras del corazón shamánico. Azares y dilemas Qom. En: Avá, nº 16

    OpenAIRE

    Wright, Pablo

    2009-01-01

    En este artículo analizo dilemas y paradojas que plantea la modernidad en el caso de los Takshek Qom o tobas del oriente de Formosa (Argentina). Para ello me centro en la experiencia del lkillakte o corazón como uno de los núcleos vitales y existenciales de la persona. Allí se alojan las distintas clases de poder shamánico y también es sede de los pensamientos y las emociones. Me interesa explorar qué le pasa en términos simbólicos al corazón shamánico frente al ...

  9. Inteligencia emocional percibida y desgaste laboral en médicos internos de pregrado Perceived emotional intelligence and burnout in undergraduate medicine interns

    Directory of Open Access Journals (Sweden)

    R. Ortiz-Acosta

    2011-03-01

    Full Text Available Objetivo: Analizar la relación entre los niveles de inteligencia emocional percibida y desgaste laboral en médicos internos de pregrado. Sujetos y métodos: Para ello se utilizó la Trait Meta-Mood Scale, que evalúa la inteligencia emocional percibida, y el inventario de burnout de Maslach, en 44 médicos internos de pregrado de tres hospitales de los Servicios de Salud de Sonora. Resultados: El factor de atención emocional se relaciona negativamente con agotamiento. Claridad correlaciona de manera positiva con reparación emocional y realización personal, y de forma negativa con agotamiento y despersonalización. Reparación de las emociones correlaciona de forma negativa con agotamiento y despersonalización, y de manera positiva con realización personal. Los análisis de regresión revelaron que el desgaste laboral del médico de pregrado se explicaba por una baja atención emocional y falta de claridad en sus emociones. Conclusión: Estos hallazgos evidencian que ciertos factores emocionales deben tenerse en cuenta para explicar el desgaste laboral en el médico interno de pregrado.Aim: To analyze the relationship between the levels of perceived emotional intelligence and burnout in undergraduate medicine interns. Subjects and methods: For this, we used the Trait Meta-Mood Scale, which evaluates perceived emotional intelligence, the Maslach Burnout Inventory, in 44 undergraduate interns from three hospitals of Sonora Health Services. Results: The factor of emotional attention is related negatively with exhaustion. Clarity correlates in a positive way with emotional repair and self-fulfillment; and negatively with exhaustion and depersonalization. Emotional repair correlates in a negative way with exhaustion and depersonalization, and positively to self-fulfillment. Regression analyses showed that burnout in undergraduate interns was explained by a low emotional attention and a lack of clarity in their emotions. Conclusion: Those

  10. La calidad percibida desde la perspectiva de género en un hospital de complejdad asistencial máxima

    Directory of Open Access Journals (Sweden)

    Pilar Arrizabalaga

    2010-12-01

    Full Text Available Objetivo: Analizar la calidad percibida en un hospital de tercer nivel desde la perspectiva de género. Métodos: Análisis de los cuestionarios de satisfacción a los/las pacientes ingresados/as durante octubre y noviembre 2003-2005 con el test de la T de Student-Fisher y la prueba de 2. Resultados: De los 2660 cuestionarios, 44,7% fueron de hombres, 55,55 ± 17,3 años, y 53,3% de mujeres, 48 ± 18,4 años. El 36% tenía estudios primarios, 18% formación profesional y el 22% universitarios. Los hombres conocían las normas de hospitalización y el nombre del médico/a mejor que las mujeres (p < 0.0001. Las mujeres se consideraron mejor informadas sobre su enfermedad que los hombres (p < 0.05. Ambos grupos volverían a elegir el mismo centro. Conclusión: Las diferencias en la calidad percibida entre ambos sexos sugieren que el género debería contemplarse en sistemas organizativos centrados en los cuidados del paciente. Objective: To analyse the perceived assistance quality of third level hospital inpatients, carrying out an essay that takes in account only the gender of the surveyed. Methods: Descriptive analysis of surveys of the inpatients between October and November 2003-2005 with the T of Student-Fisher and the 2 tests respectively. Results: From 2660 surveyed, 44,7% were men aged 55,55 ± 17,3, and 53,3% were women aged 48 ± 18,4. 36% had a primary school degree, 18% professional and 22% university studies. Men were considered better informed than women about hospitalization rules and knew better the name of their doctors (p < 0.0001. Women were better informed about their illness (p < 0.05. There was no difference in the choice of the same centre for the future. Conclusions: The perceived assistance quality is influenced by gender, so it should be taken into account in organizing systems oriented to satisfying the patient needs.

  11. La centralidad en las comunicaciones y la influencia percibida en los pequeños grupos The communication centrality and the perceived influence in small groups

    Directory of Open Access Journals (Sweden)

    Nancy Noemi Terroni

    2003-06-01

    Full Text Available Este trabajo reporta los resultados de medidas del análisis de redes en la comunicación de pequeños grupos que resuelven una tarea de recuperación de memoria y su asociación con la influencia percibida. El reactivo empleado es una historia y los 65 participantes, alumnos de la Universidad Nacional de Mar del Plata, debieron reconstruir la misma primero en forma individual, luego grupal colaborativa y nuevamente en forma individual. Se registraron las interacciones grupales con comunicación cara a cara y mediada por computadora; se analizaron las medidas de prominencia, la centralidad y el prestigio de la comunicación y el tipo de alocución, orientado a la gestión grupal o hacia la tarea. Se observaron asociaciones significativas entre las medidas reticulares y la influencia percibida para ambos medios de comunicación y se hallaron diferencias en la comunicación de gestión grupal. Se discuten estos resultados con relación a las restricciones que imponen los canales de comunicación mediados.This work reports reticular measures of the social network analysis in the communication of small groups while solving a recall memory task and their association with the perceived influence. The task used is a story and the 65 subjects, students at the Mar del Plata University had to reconstruct the story, first individually, then in collaborative groups and again individually. The subjects’ interactions in face to face and computer mediated communication groups were recorded; the prominence measures, the centrality and the prestige of the communication and the type of speech were analyzed, oriented to the group management or towards the task (conceptual. Significant associations between the reticular measures and the perceived influence were observed, for both media, and differences in the group management communications were found. These results in relation to the restrictions of the communication mediated channels are discussed.

  12. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    Science.gov (United States)

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

  13. Collective search by ants in microgravity

    Directory of Open Access Journals (Sweden)

    Stefanie M. Countryman

    2015-03-01

    Full Text Available The problem of collective search is a tradeoff between searching thoroughly and covering as much area as possible. This tradeoff depends on the density of searchers. Solutions to the problem of collective search are currently of much interest in robotics and in the study of distributed algorithms, for example to design ways that without central control robots can use local information to perform search and rescue operations. Ant colonies operate without central control. Because they can perceive only local, mostly chemical and tactile cues, they must search collectively to find resources and to monitor the colony's environment. Examining how ants in diverse environments solve the problem of collective search can elucidate how evolution has led to diverse forms of collective behavior. An experiment on the International Space Station in January 2014 examined how ants (Tetramorium caespitum perform collective search in microgravity. In the ISS experiment, the ants explored a small arena in which a barrier was lowered to increase the area and thus lower ant density. In microgravity, relative to ground controls, ants explored the area less thoroughly and took more convoluted paths. It appears that the difficulty of holding on to the surface interfered with the ants’ ability to search collectively. Ants frequently lost contact with the surface, but showed a remarkable ability to regain contact with the surface.

  14. Ant-lepidopteran associations along African forest edges

    Science.gov (United States)

    Dejean, Alain; Azémar, Frédéric; Libert, Michel; Compin, Arthur; Hérault, Bruno; Orivel, Jérôme; Bouyer, Thierry; Corbara, Bruno

    2017-02-01

    Working along forest edges, we aimed to determine how some caterpillars can co-exist with territorially dominant arboreal ants (TDAAs) in tropical Africa. We recorded caterpillars from 22 lepidopteran species living in the presence of five TDAA species. Among the defoliator and/or nectarivorous caterpillars that live on tree foliage, the Pyralidae and Nymphalidae use their silk to protect themselves from ant attacks. The Notodontidae and lycaenid Polyommatinae and Theclinae live in direct contact with ants; the Theclinae even reward ants with abundant secretions from their Newcomer gland. Lichen feeders (lycaenid; Poritiinae), protected by long bristles, also live among ants. Some lycaenid Miletinae caterpillars feed on ant-attended membracids, including in the shelters where the ants attend them; Lachnocnema caterpillars use their forelegs to obtain trophallaxis from their host ants. Caterpillars from other species live inside weaver ant nests. Those of the genus Euliphyra (Miletinae) feed on ant prey and brood and can obtain trophallaxis, while those from an Eberidae species only prey on host ant eggs. Eublemma albifascia (Erebidae) caterpillars use their thoracic legs to obtain trophallaxis and trophic eggs from ants. Through transfer bioassays of last instars, we noted that herbivorous caterpillars living in contact with ants were always accepted by alien conspecific ants; this is likely due to an intrinsic appeasing odor. Yet, caterpillars living in ant shelters or ant nests probably acquire cues from their host colonies because they were considered aliens and killed. We conclude that co-evolution with ants occurred similarly in the Heterocera and Rhopalocera.

  15. Pheromone disruption of Argentine ant trail integrity

    Science.gov (United States)

    Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.

    2008-01-01

    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

  16. Rousseau y la superación del dilema iusnaturalismo-convencionalismo

    Directory of Open Access Journals (Sweden)

    Rubio Carracedo, José

    2001-06-01

    Full Text Available Is Rousseau a representative of the law of nature tradition or a conventionalist? The debate is old enough, but R. Derathé's authority, adscribing Rousseau to the former tradition, seems to have prevailed, even over Vaughan's interpretation, that considers him a conventionalist. Indeed, we can find texts or paragraphs of both tendencies. Hence a genealogical study becomes necessary, as the one presented here. Hesitations appear as early as in the Discourse on inequality and are clear in the Geneva Manuscript, but Rousseau finally elaborates his own methodology based on the dialectics conscience-reason. I have proposed to call this methodology constructivist. It neatly appears in the Social Contract and in Emile. However, there are still paragraphs mixing the above cited traditions, and there are quite a few examples of the former one. The law of nature tradition provided the dominant political language of the age, thanks mainly to the iurisconsulti. Rousseau criticizes them, but he does the same with Hobbes.This paper aims to contribute to clarifying definitely this issue, thats heds light on the real meaning Rousseau had given to the social contract and to his democratic model.

    ¿Es Rousseau iusnaturalista o convencionalista? La polémica ha sido larga pero parece haberse impuesto la autoridad de R. Derathé adscribiéndole al iusnaturalismo, pese a que Vaughan le había adscrito antes al convencionalismo. En realidad es posible encontrar textos o párrafos de ambos enfoques. Por eso se hace preciso un estudio genealógico como el que presentamos. Las vacilaciones aparecen ya en el Discurso sobre la desigualdad, y son claras y se hacen más patentes en el Manuscrito de Ginebra, pero Rousseau encuentra finalmente su propia metodología basada en la dialéctica conciencia-razón. He propuesto denominar constructivista esta nueva metodología, que aparece ya netamente en el Contrato social y

  17. Desarrollo y Validación del Cuestionario para la Evaluación de la Calidad Percibida en Servicios Deportivos

    Directory of Open Access Journals (Sweden)

    Pablo Gálvez Ruiz

    2015-01-01

    Full Text Available El objetivo del presente estudio fue examinar la estructura factorial del Cuestionario de Evaluación de la Calidad Percibida en Servicios Deportivos. Para ello se realizaron tres estudios diferentes con una muestra total de 867 usuarios (426 hombres y 431 mujeres, con edades comprendidas entre los 14 y los 81 años. Los resultados mostraron que el instrumento presenta adecuadas propiedades psicométricas. El índice de discriminación de los ítems mostró valores superiores a .40 y el nivel de consistencia interna fue adecuado en todas las subescalas ( > 0,75. El análisis de componentes principales mostró una solución estable compuesta por once factores, que explicaban más del 50% de la varianza en cada una. Los índices de bondad de ajuste para el modelo obtenido y puesto a prueba mediante análisis factorial confirmatorio fueron adecuados. Además, esta estructura dimensional se mostró invariante en función del género, mostrando equivalencia factorial y métrica. Futuros estudios deberían aplicarse a servicios de naturaleza y titularidad diferente, así como examinar la invarianza de medición en otras culturas.

  18. Influencia de la dinámica familiar percibida en el proyecto de vida en escolares de una institución educativa de Lima

    Directory of Open Access Journals (Sweden)

    Miguel Barboza-Palomino

    Full Text Available Resumen La investigación tuvo como objetivo analizar la influencia de la dinámica familiar percibida en la planeación del proyecto de vida en escolares de 4to año de secundaria de ambos sexos entre 14 a 18 años de una institución educativa del distrito de San Juan de Lurigancho, Lima. Se siguió metodología cualitativa, utilizando la técnica de la entrevista cualitativa que se aplicó a un total de 12 personas. Por otra parte, también se ejecutaron dos grupos focales integrados por siete participantes cada uno. La información recabada fue analizada empleando elementos de la teoría fundamentada y axiomas de conjuntos, empleándose como apoyo el software para el análisis cualitativo de datos Atlas.ti, v. 7.5. Los resultados evidencian que los participantes perciben que factores de la dinámica familiar como el ambiente familiar, la comunicación familiar y tipo de estructura familiar influyen en la construcción de su proyecto de vida.

  19. Barreras percibidas y actividad física: el autoinforme de barreras para la práctica de ejercicio físico

    Directory of Open Access Journals (Sweden)

    Jordi Ni\\u00F1erola i Maym\\u00ED

    2006-01-01

    Full Text Available La Psicología del Deporte y la Psicología de la Salud han identificado el sedentarismo como un factor de riesgo creciente para la salud. Esto ha conllevado que ambas disciplinas se hayan interesado por el estudio de la motivación y la adherencia a la actividad física. El objetivo del presente estudio es validar un cuestionario de evaluación de las barreras que perciben los sujetos para la práctica de ejercicio físico el Autoinforme de Barreras para la Práctica de Ejercicio Físico (ABPEF. La versión final del ABPEF resulta un instrumento adecuado, válido y fiable, para evaluar las barreras percibidas relacionadas con la práctica de ejercicio físico. La información que ofrece el cuestionario puede resultar muy útil a nivel aplicado para planificar estrategias de adopción de un estilo de vida activo.

  20. What do myrmecophagous geckos eat when ants are not available ...

    African Journals Online (AJOL)

    Like other Pristurus species, P. samhaensis on Samha and P. sokotranus on Socotra were highly myrmecophagous (76.7% and 38.6% ants, respectively). However, ants were absent from the diet of P. samhaensis on Darsa. In contrast to the rich native ant fauna of the other islands, only one ant species was reported for ...

  1. Ants as tools in sustainable agriculture

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2015-01-01

    1. With an expanding human population placing increasing pressure on the environment, agriculture needs sustainable production that can match conventional methods. Integrated pest management (IPM) is more sustainable, but not necessarily as efficient as conventional non-sustainable measures. 2...... in multiple crops. Their efficiency is comparable to chemical pesticides or higher, while at lower costs. They provide a rare example of documented efficient conservation biological control. 3. Weaver ants share beneficial traits with almost 13 000 other ant species and are unlikely to be unique...... of agricultural systems, this review emphasizes the potential of managing ants to achieve sustainable pest management solutions. The synthesis suggests future directions and may catalyse a research agenda on the utilization of ants, not only against arthropod pests, but also against weeds and plant diseases...

  2. Kunstikriitik Ants Juske sai doktoriks / Neeme Korv

    Index Scriptorium Estoniae

    Korv, Neeme, 1974-

    2003-01-01

    Tartu Kõrgema Kunstikooli rektor Ants Juske kaitses 7. veebruaril Tallinnas Kunstiakadeemias edukalt doktoriväitekirja, juhendajaks oli professor Boris Bernštein ning oponeerisid doktor Altti Kuusamo Soomest ja professor Peeter Tulviste

  3. Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    the more basal attine genera use substrates such as flowers, plant debris, small twigs, insect feces and insect carcasses. This diverse array of fungal substrates across the attine lineage implies that the symbiotic fungus needs different enzymes to break down the plant material that the ants provide...... or different efficiencies of enzyme function. Fungal enzymes that degrade plant cell walls may have functionally co-evolved with the ants in this scenario. We explore this hypothesis with direct measurements of enzyme activity in fungus gardens in 12 species across 8 genera spanning the entire phylogeny...... and diversity of life-styles within the attine clade. We find significant differences in enzyme activity between different genera and life-styles of the ants. How these findings relate to attine ant coevolution and crop optimization are discussed....

  4. Exotic ants (Hymenoptera, Formicidae) of Ohio

    OpenAIRE

    Ivanov,Kal

    2016-01-01

    The worldwide transfer of plants and animals outside their native ranges is an ever increasing problem for global biodiversity. Ants are no exception and many species have been transported to new locations often with profound negative impacts on local biota. The current study is based on data gathered since the publication of the “Ants of Ohio” in 2005. Here I expand on our knowledge of Ohio’s myrmecofauna by contributing new records, new distributional information and natural history notes. ...

  5. Improving Emergency Management by Modeling Ant Colonies

    Science.gov (United States)

    2015-03-01

    perform functions such as nursing the brood or maintaining the nest. The more mature workers will begin to travel outside the nest to perform foraging...small sized ants predominantly act in functional roles such as nurses or transport services within the nest. The larger sizes predominantly function...stages: the founding stage, the ergonomic stage, and the reproductive stage. The founding stage is marked by a queen ant successful mating and laying

  6. Extrafloral nectar fuels ant life in deserts

    OpenAIRE

    Aranda-Rickert, Adriana; Diez, Patricia; Marazzi, Brigitte

    2014-01-01

    Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal dese...

  7. Chemically armed mercenary ants protect fungus-farming societies

    DEFF Research Database (Denmark)

    Adams, Rachelle Martha Marie; Liberti, Joanito; Illum, Anders A.

    2013-01-01

    guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit......The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated...... parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few...

  8. Toxic industrial deposit remediation by ant activity

    Science.gov (United States)

    Jilkova, Veronika; Frouz, Jan

    2016-04-01

    Toxic industrial deposits are often contaminated by heavy metals and the substrates have low pH values. In such systems, soil development is thus slowed down by high toxicity and acidic conditions which are unfavourable to soil fauna. Ants (Hymenoptera, Formicidae) are considered tolerant to heavy metal pollution and are known to increase organic matter content and microbial activity in their nests. Here, we focused on soil remediation caused by three ant species (Formica sanguinea, Lasius niger, and Tetramorium sp.) in an ore-washery sedimentation basin near Chvaletice (Czech Republic). Soil samples were taken from the centre of ant nests and from the nest surroundings (>3 m from nests). Samples were then analyzed for microbial activity and biomass and contents of organic matter and nutrients. As a result, ant species that most influenced soil properties was F. sanguinea as there were higher microbial activity and total nitrogen and ammonia contents in ant nests than in the surrounding soil. We expected such a result because F. sanguinea builds conspicuous large nests and is a carnivorous species that brings substantial amounts of nitrogen in insect prey to their nests. Effects of the other two ant species might be lower because of smaller nests and different feeding habits as they rely mainly on honeydew from aphids or on plant seeds that do not contain much nutrients.

  9. Congestion and communication in confined ant traffic

    Science.gov (United States)

    Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A. D.; Goldman, Daniel I.

    2014-03-01

    Many social animals move and communicate within confined spaces. In subterranean fire ants Solenopsis invicta, mobility within crowded nest tunnels is important for resource and information transport. Within confined tunnels, communication and traffic flow are at odds: trafficking ants communicate through tactile interactions while stopped, yet ants that stop to communicate impose physical obstacles on the traffic. We monitor the bi-directional flow of fire ant workers in laboratory tunnels of varied diameter D. The persistence time of communicating ant aggregations, τ, increases approximately linearly with the number of participating ants, n. The sensitivity of traffic flow increases as D decreases and diverges at a minimum diameter, Dc. A cellular automata model incorporating minimal traffic features--excluded volume and communication duration--reproduces features of the experiment. From the model we identify a competition between information transfer and the need to maintain jam-free traffic flow. We show that by balancing information transfer and traffic flow demands, an optimum group strategy exists which maximizes information throughput. We acknowledge funding from NSF PoLS #0957659 and #PHY-1205878.

  10. Fire ants perpetually rebuild sinking towers

    Science.gov (United States)

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L.; Tovey, Craig

    2017-07-01

    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

  11. TEORIAS ORGANIZACIONAIS E O DILEMA AMBIENTAL: UM TRATAMENTO PARA A MUDANÇA ORGANIZACIONAL?

    Directory of Open Access Journals (Sweden)

    Cleber J. C. Dutra

    2005-11-01

    -style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->

    Resumo

    Este é um ensaio reflexivo dirigido à análise de limitações de Teorias Organizacionais na abordagem da temática ambiental.  Propõe-se um dilema hipotético como exercício de análise, objetivando destacar inconsistências entre os enfoques das teorias para caracterizar o  "ambiente".  As limitações podem refletir-se como problemas para integração de múltiplas visões parciais do ambiente, gerando interações deficientes entre os envolvidos com as questões ambientais.  Ao destacar fundamentos relacionais importantes para a gestão, são dedicadas considerações quanto ao uso alternativo de propostas conceituais ainda não devidamente dedicadas ao assunto, como o caso das teorias da Mudança Organizacional.  Uma revisão dos artigos publicados com enfoque ambiental nos EnANPADs entre 1997 e 2004 confirma o car

  12. Infância e educação: novos estudos e velhos dilemas da pesquisa educacional

    Directory of Open Access Journals (Sweden)

    Eloísa Acires Candal Rocha

    2013-12-01

    Full Text Available Este artigo toma como objeto de análise a produção acadêmica relacionada ao tema educação e infância, no âmbito dos programas de pós-graduação em Educação da região sul do Brasil, nos últimos cinco anos (2007-2011. Tem o objetivo de buscar indicativos das interlocuções dessa produção com a educação nas creches, pré-escolas e escolas. Para o desenvolvimento da análise, retomaram-se alguns velhos dilemas da pesquisa educacional, em especial aqueles que envolvem a relação entre teoria e prática, uma vez que uma perspectiva avaliativa da contribuição da pós-graduação para a educação básica brasileira exige um olhar sobre as relações da pesquisa com as práticas pedagógicas nos sistemas educativos. Sem a pretensão de realizar um estado da arte do referido período, buscou-se identificar as perspectivas e bases analíticas desse conjunto de investigações, o qual revela um fortalecimento dos diálogos possíveis entre pós-graduação e educação básica, a partir da abertura científica para colaborações disciplinares e teóricas na direção de consolidar uma ciência da educação cujo foco são os processos educativos que envolvem as crianças pequenas, considerando sua concretude social e cultural. As análises indicam a necessidade de estar alerta para os riscos de superficializações e generalizações em que o interesse em conhecer as crianças e sua infância coloca para a pesquisa educacional realizada contemporaneamente: a reavaliação de sua especificidade.

  13. TEORIAS ORGANIZACIONAIS E O DILEMA AMBIENTAL: UM TRATAMENTO PARA A MUDANÇA ORGANIZACIONAL? [doi: 10.5329/RECADM.20050402007

    Directory of Open Access Journals (Sweden)

    Cleber J. C. Dutra

    2005-11-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 Resumo Este é um ensaio reflexivo dirigido à análise de limitações de Teorias Organizacionais na abordagem da temática ambiental.  Propõe-se um dilema hipotético como exercício de análise, objetivando destacar inconsistências entre os enfoques das teorias para caracterizar o  "ambiente".  As limitações podem refletir-se como problemas para integração de múltiplas visões parciais do ambiente, gerando interações deficientes entre os envolvidos com as questões ambientais.  Ao destacar fundamentos relacionais importantes para a gestão, são dedicadas considerações quanto ao uso alternativo de propostas conceituais ainda não devidamente dedicadas ao assunto, como o caso das teorias da Mudança Organizacional.  Uma revisão dos artigos publicados com enfoque ambiental nos EnANPADs entre 1997 e 2004 confirma o caráter inédito desta alternativa de abordagem.   Palavras-chave: Gestão  Ambiental;  Mudança Organizacional;  Teorias Organizacionais.   Abstract This is a reflexive essay addressed to the analysis of the limitations of Organisational Theories on approaching environmental subjects.  It proposes a hypothetical dilemma as an analytical exercise, intending to highlight inconsistencies among the approaches of Theories when defining  “the environment”.   The limitations can render the integration of multiple partial visions of the environment highly problematic, resulting in deficient interactions between people involved in environmental issues.  Discussing valuable relational fundamentals to the managerial praxis, the essay evaluates the alternative use of conceptual propositions still not applied to the subject, such as the theories on Organisational Change.   To support this claim of originality in the approach, the essay presents results of a review of EnANPAD papers published on environmental issues from 1997 to 2004.

  14. The distribution of weaver ant pheromones on host trees

    DEFF Research Database (Denmark)

    Offenberg, Joachim

    2007-01-01

    The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested for ...... to leaves. Also there was a positive correlation between spot density and the likelihood of being detected by ants. Anal spots may thus function as reliable cues to interacting species and be an important factor in shaping the community around Oecophylla colonies.......The visible anal spots deposited by Oecophylla smaragdina ants have been suggested to deter ant prey, affect interspecific competition and facilitate mutualists and parasites in tracking down Oecophylla ants. I measured the density of anal spots on host trees with and without ants and tested...... for correlations between spot density, ant activity and the likelihood of being detected by an ant. Spots were only found on trees with ants. On ant-trees, spots were distributed throughout the trees but with higher densities in areas with high ant activity and pheromone densities were higher on twigs compared...

  15. Adaptación Universitaria y Su Relación con la Salud Percibida en Una Muestra de Jóvenes de Perú/Adaptation to College and Its Relation to Perceived Health in A Sample of Peruvian Students/Adaptação Universitária e Sua Relação com a Saúde Percebida Numa Amostra de Jovens do Peru

    Directory of Open Access Journals (Sweden)

    CECILIA CHAU

    2015-02-01

    Full Text Available El propósito de este estudio fue analizar la relación entre la salud percibida y la adaptación a la vida universitaria de un grupo de jóvenes estudiantes de Lima, Perú. Para ello, se aplicó el Cuestionario de Adaptación Universitaria (QVA -R y una medida de salud percibida, a una muestra de 281 estudiantes universitarios. Los resultados mostraron una relación positiva entre la salud percibida y las cinco áreas que miden la adaptación universitaria. El área Personal presentó la mayor relación con la salud percibida. Esto evidenció la importancia de la relación que existe entre la habilidad para adaptarse a la vida universitaria y la percepción de salud de los alumnos.

  16. Calidad de servicio percibida por los usuarios de los programas de postgrado en gerencia de la Facultad de Ciencias Económicas y Sociales

    Directory of Open Access Journals (Sweden)

    Dianela Carolina Zuleta Zuleta

    2014-01-01

    Full Text Available El artículo es producto de una investigación cuyo objetivo fue analizar calidad de servicio percibida por los usuarios de los Programas de Postgrado en Gerencia de la Facultad de Ciencias Económicas y Sociales (FCES-LUZ de la Universidad del Zulia. La investigación es de tipo descriptivo con diseño no experimental, transaccional y de campo. La población estuvo conformada por estudiantes activos, de diferentes programas de postgrado ofrecidos por FCES-LUZ. El tamaño de la muestra se determinó a través de muestreo aleatorio simple con asignación proporcional. El instrumento de recolección de datos estuvo constituido por un cuestionario estructurado, contentivo de la variable que se estudió, basado en el modelo SERVQUAL. El mismo fue validado por expertos. La conabilidad se determinó a través del coeciente de Alpha Cronbach. Los resultados indican que el usuario calica el servicio como poco satisfactorio, observándose debilidades en la ejecución de los servicios complementarios a los procesos de enseñanza, y donde el indicador seguridad personal revela los niveles de insatisfacción más elevados. Se recomienda la creación y puesta en práctica de campañas orientadas al desarrollo de una cultura de servicio, centradas en atender las expectativas y necesidades del usuario.

  17. Fuzzy Rules for Ant Based Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Amira Hamdi

    2016-01-01

    Full Text Available This paper provides a new intelligent technique for semisupervised data clustering problem that combines the Ant System (AS algorithm with the fuzzy c-means (FCM clustering algorithm. Our proposed approach, called F-ASClass algorithm, is a distributed algorithm inspired by foraging behavior observed in ant colonyT. The ability of ants to find the shortest path forms the basis of our proposed approach. In the first step, several colonies of cooperating entities, called artificial ants, are used to find shortest paths in a complete graph that we called graph-data. The number of colonies used in F-ASClass is equal to the number of clusters in dataset. Hence, the partition matrix of dataset founded by artificial ants is given in the second step, to the fuzzy c-means technique in order to assign unclassified objects generated in the first step. The proposed approach is tested on artificial and real datasets, and its performance is compared with those of K-means, K-medoid, and FCM algorithms. Experimental section shows that F-ASClass performs better according to the error rate classification, accuracy, and separation index.

  18. Enfoque multricriterios al estudio de la imagen empresarial y posicionamiento competitivo a través de la calidad percibida en el servicio de elaboración de diseños

    OpenAIRE

    María de Lourdes Artola Pimentel

    2010-01-01

    El concepto de imagen visto como el conjunto de representaciones mentales que surgen en el espíritu del público que reflejan las manifestaciones de una cultura en las percepciones del entorno puede abordarse para su estudio desde el ángulo de la Calidad Percibida donde se valora el juicio del cliente resultante de la comparación entre percepciones y expectativas. En el presente trabajo se expone un modelo que permite el estudio de la imagen y el posicionamiento de ...

  19. Kin-informative recognition cues in ants

    DEFF Research Database (Denmark)

    Nehring, Volker; Evison, Sophie E F; Santorelli, Lorenzo A

    2011-01-01

    behaviour is thought to be rare in one of the classic examples of cooperation--social insect colonies--because the colony-level costs of individual selfishness select against cues that would allow workers to recognize their closest relatives. In accord with this, previous studies of wasps and ants have...... found little or no kin information in recognition cues. Here, we test the hypothesis that social insects do not have kin-informative recognition cues by investigating the recognition cues and relatedness of workers from four colonies of the ant Acromyrmex octospinosus. Contrary to the theoretical...... prediction, we show that the cuticular hydrocarbons of ant workers in all four colonies are informative enough to allow full-sisters to be distinguished from half-sisters with a high accuracy. These results contradict the hypothesis of non-heritable recognition cues and suggest that there is more potential...

  20. Ant parasite queens revert to mating singly

    DEFF Research Database (Denmark)

    Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe

    2004-01-01

    quantified and they tend to be similar in related species. Here we compare the mating strategies of the leaf-cutting ant Acromyrmex echinatior and its recently derived social parasite Acromyrmex insinuator, which is also its closest relative 2 (see Fig. 1 ). We find that although the host queens mate with up......A parasitic ant has abandoned the multiple mating habit of the queens of its related host. Multiple mating (polyandry) is widespread among animal groups, particularly insects 1 . But the factors that maintain it and underlie its evolution are hard to verify because benefits and costs are not easily...... to a dozen different males, the social parasite mates only singly. This rapid and surprising reversion to single mating in a socially parasitic ant indicates that the costs of polyandry are probably specific to a free-living lifestyle....

  1. The worldwide expansion of the Argentine ant

    DEFF Research Database (Denmark)

    Vogel, Valerie; Pedersen, Jes Søe; Giraud, Tatiana

    2010-01-01

    Aim The aim of this study was to determine the number of successful establishments of the invasive Argentine ant outside native range and to see whether introduced supercolonies have resulted from single or multiple introductions. We also compared the genetic diversity of native versus introduced...... supercolonies to assess the size of the propagules (i.e. the number of founding individuals) at the origin of the introduced supercolonies. Location Global. Methods We used mitochondrial DNA (mtDNA) markers and microsatellite loci to study 39 supercolonies of the Argentine ant Linepithema humile covering both......) and secondary introductions (from sites with established invasive supercolonies) were important in the global expansion of the Argentine ant. In combination with the similar social organization of colonies in the native and introduced range, this indicates that invasiveness did not evolve recently as a unique...

  2. Desert ants learn vibration and magnetic landmarks.

    Directory of Open Access Journals (Sweden)

    Cornelia Buehlmann

    Full Text Available The desert ants Cataglyphis navigate not only by path integration but also by using visual and olfactory landmarks to pinpoint the nest entrance. Here we show that Cataglyphis noda can additionally use magnetic and vibrational landmarks as nest-defining cues. The magnetic field may typically provide directional rather than positional information, and vibrational signals so far have been shown to be involved in social behavior. Thus it remains questionable if magnetic and vibration landmarks are usually provided by the ants' habitat as nest-defining cues. However, our results point to the flexibility of the ants' navigational system, which even makes use of cues that are probably most often sensed in a different context.

  3. Ant-plants and fungi: a new threeway symbiosis.

    Science.gov (United States)

    Defossez, Emmanuel; Selosse, Marc-André; Dubois, Marie-Pierre; Mondolot, Laurence; Faccio, Antonella; Djieto-Lordon, Champlain; McKey, Doyle; Blatrix, Rumsaïs

    2009-06-01

    Symbioses between plants and fungi, fungi and ants, and ants and plants all play important roles in ecosystems. Symbioses involving all three partners appear to be rare. Here, we describe a novel tripartite symbiosis in which ants and a fungus inhabit domatia of an ant-plant, and present evidence that such interactions are widespread. We investigated 139 individuals of the African ant-plant Leonardoxa africana for occurrence of fungus. Behaviour of mutualist ants toward the fungus within domatia was observed using a video camera fitted with an endoscope. Fungi were identified by sequencing a fragment of their ribosomal DNA. Fungi were always present in domatia occupied by mutualist ants but never in domatia occupied by opportunistic or parasitic ants. Ants appear to favour the propagation, removal and maintenance of the fungus. Similar fungi were associated with other ant-plants in Cameroon. All belong to the ascomycete order Chaetothyriales; those from L. africana formed a monophyletic clade. These new plant-ant-fungus associations seem to be specific, as demonstrated within Leonardoxa and as suggested by fungal phyletic identities. Such tripartite associations are widespread in African ant-plants but have long been overlooked. Taking fungal partners into account will greatly enhance our understanding of symbiotic ant-plant mutualisms.

  4. Ants of the Peloponnese, Greece (Hymenoptera: Formicidae

    Directory of Open Access Journals (Sweden)

    Borowiec Lech

    2017-09-01

    Full Text Available This paper relates to material obtained during two field trips to the Peloponnese in 2013 and 2016. With the inclusion of some hitherto unpublished ant material, it gives new records from a total of 92 sampling localities. 129 species (including morphospecies not attributed to any known taxon of ants have been recorded from the Peloponnese (southern Greece, 27 of which have been recorded from this region for the first time. Lasius reginae and 5 other morphospecies attributed only to species complexes are new to Greece.

  5. Image Edge Tracking via Ant Colony Optimization

    Science.gov (United States)

    Li, Ruowei; Wu, Hongkun; Liu, Shilong; Rahman, M. A.; Liu, Sanchi; Kwok, Ngai Ming

    2018-04-01

    A good edge plot should use continuous thin lines to describe the complete contour of the captured object. However, the detection of weak edges is a challenging task because of the associated low pixel intensities. Ant Colony Optimization (ACO) has been employed by many researchers to address this problem. The algorithm is a meta-heuristic method developed by mimicking the natural behaviour of ants. It uses iterative searches to find the optimal solution that cannot be found via traditional optimization approaches. In this work, ACO is employed to track and repair broken edges obtained via conventional Sobel edge detector to produced a result with more connected edges.

  6. Revista Brasileira de Ciências do Esporte: dificuldades, desafios e dilemas da editoração científica

    Directory of Open Access Journals (Sweden)

    Alexandre Fernandez Vaz

    2014-12-01

    Full Text Available O artigo discute desafios, dificuldades e dilemas da editoração de periódicos científicos, a partir da experiência como editores da Revista Brasileira de Ciências do Esporte (RBCE. Problematiza a necessidade da internacionalização da produção do conhecimento e dos periódicos nacionais, um imperativo que se apresenta aos editores das revistas na atualidade, questão fortemente vinculada às expectativas de progresso na pós-graduação. Aponta vicissitudes desse quadro para uma área de intervenção e procura mostrar suas ambiguidades no que se refere às más condutas acadêmicas.

  7. O Controle da Gestão dos Recursos Públicos: Bases Conceituais e o Falso Dilema “Regularidade Versus Resultados”

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Simão Bijos

    2011-12-01

    Full Text Available Este artigo apresenta os fundamentos teóricos do controle, retratando-o, de início, como função administrativa organicamente articulada em uma estrutura piramidal de controle, constituída pelas instâncias de controles internos, auditoria interna e auditoria externa. Em paralelo, traca a distinção entre: controle e auditoria; controles internos e auditoria interna; e auditoria interna e auditoria externa. Adicionalmente, explora a conexão entre auditoria e os conceitos de teoria da agência, governança corporativa e accountability. Em particular, expõe os elementos centrais do sistema brasileiro de accountability horizontal, pertinente ao controle da gestão dos recursos públicos, com ênfase no modelo federal, e analisa a inter-relacão entre as principais vertentes desse sistema de controle, abrangendo o dilema regularidade x resultados.

  8. Gestionando la ciudadanía pluricultural: la escuela indígena en Chiapas ante los derechos culturales

    Directory of Open Access Journals (Sweden)

    Victoria Borrell Velasco

    2016-01-01

    Full Text Available En una relación intercultural históricamente asimétrica, las formulaciones que afectan a las oportunidades educativas de los pue - blos originarios en el sistema público de educación se enfrentan a múl - tiples obstáculos. La enculturación en las escuelas indígenas dificulta el desarrollo de identidades múltiples homologables realmente funcio - nales para la construcción de una ciudadanía pluricultural, ya que se fomenta la tolerancia hacia pedagogías colonizadoras. Las tendencias que se originan a través de estos procesos educativos neocolonialistas, que atentan contra los derechos culturales reconocidos en las leyes, son conflictivas y contradictorias, tanto las que refuerzan la identidad étni - ca asumiendo una posición subalterna como las que la rechazan bus - cando vías de asimilación. En la resolución de este dilema apenas existe presencia indígena, ya que tradicionalmente, a pesar de los desarrollos normativos en el marco de los derechos culturales, los pueblos origina - rios quedan relegados de las consideraciones y de la toma de decisiones relacionadas con la educación. Este trabajo de investigación pretende evidenciar tanto las prin - cipales actuaciones del sistema educativo nacional en las escuelas de población originaria, ante el reto de los derechos culturales, como identificar las respuestas de los pueblos indígenas en relación con estos derechos en el estado de Chiapas.

  9. Oecophylla smaragdina food conversion efficiency: prospects for ant farming

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim

    2011-01-01

    can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost-benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina......Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming...... selling prices these efficiencies led to rates of return from 1.52 to 4.56, respectively, if: (i) protein is supplied from commercial products; or (ii) alternatively supplied from free sources such as insects and kitchen waste. These results suggest that Oecophylla ant farming may become highly profitable...

  10. Hybrid Bee Ant Colony Algorithm for Effective Load Balancing And ...

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    Ant Colony algorithm is used in this hybrid Bee Ant Colony algorithm to solve load balancing issues ... Genetic Algorithm (MO-GA) for dynamic job scheduling that .... Information Networking and Applications Workshops. [7]. M. Dorigo & T.

  11. The use of weaver ants (Oecophylla spp.) in tropical agriculture

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim

    2011-01-01

    by the consumed pest insects, can be harvested and utilised for nutrition as they are tasty and high in proteins, vitamins and minerals. Thus, plantations may function as ant farms and in addition to plant production also hosts the production of edible animal protein. In this setup harmful pest insects are turned...... farming as a way forward to solve an increasing future demand for protein. Weaver ant farming may build on natural food collected by the ants or alternatively be boosted by feeding the ant colonies actively with protein and sugar. In both cases, when ant biocontrol is combined with ant farming......, the environmental cost of protein production may fall even lower than for other insects as the ants feed on pests that would otherwise reduce the plant yield and since the farming area is simultaneously in use for plant production. In this presentation I provide data showing (i) how the harvest of ants can...

  12. Dealing with water deficit in Atta ant colonies: large ants scout for water while small ants transport it

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Da-Silva

    2012-07-01

    Leafcutter ants (Atta sexdens rubropilosa (Forel 1908 have an elaborate social organization, complete with caste divisions. Activities carried out by specialist groups contribute to the overall success and survival of the colony when it is confronted with environmental challenges such as dehydration. Ants detect variations in humidity inside the nest and react by activating several types of behavior that enhance water uptake and decrease water loss, but it is not clear whether or not a single caste collects water regardless of the cost of bringing this resource back to the colony. Accordingly, we investigated water collection activities in three colonies of Atta sexdens rubropilosa experimentally exposed to water stress. Specifically, we analyzed whether or not the same ant caste foraged for water, regardless of the absolute energetic cost (distance of transporting this resource back to the colony. Our experimental design offered water sources at 0 m, 1 m and 10 m from the nest. We studied the body size of ants near the water sources from the initial offer of water (time  =  0 to 120 min, and tested for specialization. We observed a reduction in the average size and variance of ants that corroborated the specialization hypothesis. Although the temporal course of specialization changed with distance, the final outcome was similar among distances. Thus, we conclude that, for this species, a specialist (our use of the word “specialist” does not mean exclusive task force is responsible for collecting water, regardless of the cost of transporting water back to the colony.

  13. Paradigmas y Dilemas de la Medicina Moderna en el Contexto de la atención Gerenciada de la Salud

    Directory of Open Access Journals (Sweden)

    José Felix Patiño Restrepo

    2001-12-01

    Full Text Available

    Un dilema ético y un Imperativo Social.


    El imperativo hipocrático


    La medicina es un arte, es una ciencia –la más joven de las ciencias–, es una profesión. Es la más intensamente moral de las actividades humanas, porque se fundamenta en una devoción, plasmada desde hace 2.500 años en el código hipocrático, el juramento que todos los médicos hacemos al culminar la carrera de estudiantes: dedicación total a nuestros pacientes, servicio a la sociedad.
    La medicina, cuyo servicio dio origen a muchas de las ciencias, es la más humana de todas las ciencias: es la ciencia del Hombre. En su práctica, por razón de lo impredecible del organismo humano, que es un sistema complejo adaptativo y de estructura y funcionamiento disipativo, el médico todavía tiene que basar sus decisiones en un razonamiento juicioso y una alta dosis de intuición. Como lo dice George W.
    Gray, “En la ciencia médica, los vastos océanos de ignorancia aún sobrepasan a las islas de conocimiento, tal como ocurre con casi todas las ciencias. A pesar de sus limitaciones, de su continua búsqueda de la evidencia, la medicina se perfila como uno de los grandes triunfos del espíritu humano.”
    “La medicina es, en esencia, una empresa moral fundamentada en un compromiso de confianza y honestidad.

    Este compromiso obliga al médico a mantener elevada competencia profesional para utilizarla en beneficio del paciente. Los médicos, por lo tanto, están intelectual y moralmente obligados a ser agentes del paciente en todo momento y en toda ocasión. Pero hoy tal compromiso se ve seriamente amenazado… Creemos que la profesión médica debe reafirmar la primacía de su obligación con el paciente… Sólo mediante la adecuada atención y la representación como agentes del paciente se logrará reafirmar la profesión.” Así se expresan Ralph

  14. Extended phenotype: nematodes turn ants into bird-dispersed fruits

    DEFF Research Database (Denmark)

    Hughes, D P; Kronauer, D J C; Boomsma, J J

    2008-01-01

    A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs.......A recent study has discovered a novel extended phenotype of a nematode which alters its ant host to resemble ripe fruit. The infected ants are in turn eaten by frugivorous birds that disperse the nematode's eggs....

  15. Indutores de problematização aplicados a uma aula de antropologia e dilema moral emergente

    Directory of Open Access Journals (Sweden)

    José Luís Gonçalves

    2011-12-01

    Full Text Available Este artigo relata uma experiência ocorrida no âmbito do ensino de estudantes do curso de educação social que, após terem realizado uma investigação de cariz antropológica num bairro da cidade do Porto a partir do conceito de “não-lugares” de Marc Augé, continuavam sem “ver” e “reconhecer” os seus habitantes, permanecendo estes sem rosto e nome concretos nas transcrições e nos discursos destes estudantes. O problema da invisibilidade aqui abordado foi trabalhado em sala de aula a partir do modelo teórico da problematização e aplicado, neste caso, aos dilemas morais suscitados no espírito do professor quando se apercebeu da incapacidade dos estudantes em “verem” (= reconhecerem os habitantes do bairro. O problemático surgiu quando esta experiência demonstrou que a formação humanista dos educadores sociais que se pretende alcançar ao longo do curso ainda não estava assumida. A partir desta constatação, e socorrendo-se do losango de problematização sugerido por Fabre & Musquer (2009, o docente optou por uma abordagem de ensino centrada numa epistemologia moral que realçasse as formas de olhar com indiferença ou eivadas de estereótipos ‘através de outrem’, sem levar em consideração o sujeito no seu estatuto de pessoa. Pretende futuramente retirar dos ferimentos morais (inconscientemente infligidos pelos estudantes aos habitantes ‘invisíveis’ os princípios morais do conceito de reconhecimento que, para o ser, requer a aprendizagem de uma certa literacia moral, especialmente dos educadores sociais.This article describes an experience that occurred in when teaching students of the social education degree, whom, after having conducted an anthropological investigation in a neighborhood of Oporto based on the concept of “non-places” of Marc Augé, continued not “seeing” and “recognizing” the people, who remained faceless and nameless in the specific transcripts and speeches of these

  16. Histrionicotoxin alkaloids finally detected in an ant

    DEFF Research Database (Denmark)

    Jones, Tappey H.; Adams, Rachelle Martha Marie; Spande, Thomas F.

    2012-01-01

    Workers of the ant Carebarella bicolor collected in Panama were found to have two major poison-frog alkaloids, cis- and trans-fused decahydroquinolines (DHQs) of the 269AB type, four minor 269AB isomers, two minor 269B isomers, and three isomers of DHQ 271D. For the first time in an ant, however......) sp., were found to have a very similar DHQ complex but failed to show HTXs. Several new DHQ alkaloids of MW 271 (named in the frog as 271G) are reported from the above ants that have both m/z 202 and 204 as major fragment ions, unlike the spectrum seen for the poison-frog alkaloid 271D, which has...... only an m/z 204 base peak. Found also for the first time in skin extracts from the comparison frog Oophaga granulifera of Costa Rica is a trace DHQ of MW 273. It is coded as 273F in the frog; a different isomer is found in the ant....

  17. Ants, rodents and seed predation in Proteaceae

    African Journals Online (AJOL)

    ... their nests extremely rapidly. One benefit of the ant-plant interaction may be seed escape ... (odourless to humans when dry) household glue or, b) placing seed in a Petri dish ... the layout of exclosures was completed. Response was not as.

  18. The evolution of invasiveness in garden ants

    DEFF Research Database (Denmark)

    Cremer, Sylvia; Ugelvig, Line Vej; Drijfhout, Falko P

    2008-01-01

    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its ra...

  19. The ejaculatory biology of leafcutter ants

    DEFF Research Database (Denmark)

    den Boer, Susanne; Stürup, Marlene; Boomsma, Jacobus Jan

    2015-01-01

    understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip...

  20. Mating, hybridisation and introgression in Lasius ants

    NARCIS (Netherlands)

    Have, van der T.M.; Pedersen, J.S.; Boomsma, J.J.

    2011-01-01

    Recent reviews have shown that hybridisation among ant species is likely to be more common than previously appreciated. but that documented cases of introgression remain rare. After molecular phylogenetic work had shown that European Lasius niger (LINNAEUS, 1758) and L. psammophilus SEIFERT, 1992

  1. Ants recognize foes and not friends

    Science.gov (United States)

    Guerrieri, Fernando J.; Nehring, Volker; Jørgensen, Charlotte G.; Nielsen, John; Galizia, C. Giovanni; d'Ettorre, Patrizia

    2009-01-01

    Discriminating among individuals and rejecting non-group members is essential for the evolution and stability of animal societies. Ants are good models for studying recognition mechanisms, because they are typically very efficient in discriminating ‘friends’ (nest-mates) from ‘foes’ (non-nest-mates). Recognition in ants involves multicomponent cues encoded in cuticular hydrocarbon profiles. Here, we tested whether workers of the carpenter ant Camponotus herculeanus use the presence and/or absence of cuticular hydrocarbons to discriminate between nest-mates and non-nest-mates. We supplemented the cuticular profile with synthetic hydrocarbons mixed to liquid food and then assessed behavioural responses using two different bioassays. Our results show that (i) the presence, but not the absence, of an additional hydrocarbon elicited aggression and that (ii) among the three classes of hydrocarbons tested (unbranched, mono-methylated and dimethylated alkanes; for mono-methylated alkanes, we present a new synthetic pathway), only the dimethylated alkane was effective in eliciting aggression. Our results suggest that carpenter ants use a fundamentally different mechanism for nest-mate recognition than previously thought. They do not specifically recognize nest-mates, but rather recognize and reject non-nest-mates bearing odour cues that are novel to their own colony cuticular hydrocarbon profile. This begs for a reappraisal of the mechanisms underlying recognition systems in social insects. PMID:19364750

  2. Recognition of social identity in ants

    DEFF Research Database (Denmark)

    Bos, Nick; d'Ettorre, Patrizia

    2012-01-01

    Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend...

  3. Plasmodium parasitaemia among pregnant women attending ante ...

    African Journals Online (AJOL)

    ... Ante-Natal Clinic at Military Hospital Port Harcourt, Rivers State, Nigeria using the Standard parasitological technique. Venous blood was collected from 200 pregnant women, both thick and thin blood films were made on clean greese-free glass slide and stained with 10% Giemsa stains diluted with 7.2 buffered water for ...

  4. Operant conditioning in the ant Myrmica sabuleti.

    Science.gov (United States)

    Cammaerts, M C

    2004-11-30

    Operant conditioning could be obtained in the ant Myrmica sabuleti by presenting to the workers, during a six-day period, an apparatus containing either sugared water or meat as a reward. The conditioning obtained using sugared water as a reward was short lasting. A reconditioning was more persistent and lasted four hours. The ants' response was very precise, since they exhibited it only in front of an apparatus identical to that used during the training phase. Operant conditioning obtained using meat as a reward was more pronounced than that obtained by using sugared water, probably because meat is more valuable as a reward than sugar for the species studied, which is essentially a carnivorous one. Such a conditioning was rather persistent. Indeed, a first operant conditioning obtained by using meat as a reward could still be detected after seven hours, and a reconditioning was still significant after eight hours. One day after this eight-hour period without rewarding the ants, the response was higher again and a further day later, it was still significant. Since the operant conditioning is easy to perform and quantify and since the ants' response is very precise, such a conditioning can be used for further studying M. sabuleti workers' visual perception.

  5. A global database of ant species abundances

    Science.gov (United States)

    Gibb, Heloise; Dunn, Rob R.; Sanders, Nathan J.; Grossman, Blair F.; Photakis, Manoli; Abril, Silvia; Agosti, Donat; Andersen, Alan N.; Angulo, Elena; Armbrecht, Ingre; Arnan, Xavier; Baccaro, Fabricio B.; Bishop, Tom R.; Boulay, Raphael; Bruhl, Carsten; Castracani, Cristina; Cerda, Xim; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A.; Ellison, Aaron M.; Enriquez, Martha L.; Fayle, Tom M.; Feener Jr., Donald H.; Fisher, Brian L.; Fisher, Robert N.; Fitpatrick, Matthew C.; Gomez, Cristanto; Gotelli, Nicholas J.; Gove, Aaron; Grasso, Donato A.; Groc, Sarah; Guenard, Benoit; Gunawardene, Nihara; Heterick, Brian; Hoffmann, Benjamin; Janda, Milan; Jenkins, Clinton; Kaspari, Michael; Klimes, Petr; Lach, Lori; Laeger, Thomas; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Luke, Sarah H.; Majer, Jonathan; McGlynn, Terrence P.; Menke, Sean; Mezger, Dirk; Mori, Alessandra; Moses, Jimmy; Munyai, Thinandavha Caswell; Pacheco, Renata; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M.; Resasco, Julian; Retana, Javier; Silva, Rogerio R.; Sorger, Magdalena D.; Souza, Jorge; Suarez, Andrew V.; Tista, Melanie; Vasconcelos, Heraldo L.; Vonshak, Merav; Weiser, Michael D.; Yates, Michelle; Parr, Catherine L.

    2017-01-01

    What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of more than 2693 species and 7953 morphospecies from local assemblages collected at 4212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type and degree of disturbance. The aim of compiling this dataset was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardised methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing dataset.

  6. Percepção de enfermeiros sobre dilemas éticos relacionados a pacientes terminais em Unidades de Terapia Intensiva Percepción de enfermeros sobre dilemas éticos relacionados a pacientes terminales en unidades de terapia intensiva Perception of nurses about ethical dilemmas related to terminal patients in intensive care units

    Directory of Open Access Journals (Sweden)

    Adriano Aparecido Bezerra Chaves

    2009-03-01

    Full Text Available O presente estudo teve por objetivos conhecer a percepção de enfermeiros sobre dilemas éticos existentes na assistência de enfermagem a pacientes terminais, no contexto da UTI de um hospital geral do município de São Paulo e o que é considerado para a tomada de decisão. O estudo foi realizado através de entrevistas com dez enfermeiros atuantes na UTI, utilizando uma abordagem qualitativa, conforme a análise de conteúdo. Foram encontrados dilemas éticos ligados a: diversidade de valores; presença dos pacientes terminais na UTI; incertezas sobre a terminalidade e limites de intervenção para prolongar a vida dos pacientes; discordância de tomadas de decisão; não aceitação do processo de morte pela família do paciente e a falta de esclarecimento da família e do paciente. Além disso, para tomar decisão frente aos dilemas éticos, ele considera os seus valores, a ética profissional, a empatia e o diálogo com os colegas.El presente estudio tuvo como objetivos conocer la percepción de enfermeros sobre dilemas éticos existentes en la asistencia de enfermería a pacientes terminales en el contexto de la UTI de un hospital de São Paulo y lo que se considera como la toma de decisiones. El estudio fue realizado desde una perspectiva cualitativa, utilizando el análisis de contenidos. Fueron entrevistados diez enfermeros actuantes en la UTI. El estudio mostró que los enfermeros encuentran dilemas éticos generados por diversos factores: diversidad de valores; presencia dem los pacientes terminales en la UTI; incertidumbre generada a raíz de la condición terminal; los límites de intervención para prolongar la vida; discordancia en la toma de decisiones; resistencia para aceptar el proceso de muerte por parte de la familia y la falta de esclarecimiento de la família y de los pacientes. Además, sus valores, la ética profesional, la empatía y el diálogo son tenidos en cuenta para tomar decisiones.The purpose of this study

  7. Studies on the environmental implications of ants (Hymenoptera ...

    African Journals Online (AJOL)

    A study of ants associated wh two synanthropcenvironments in Awka was carried out in 2008 using pitfall and bait traps. The study yelded a total of 561 ants wth 409 obtaned from the hemisynanthrophic environment while 192 ants were collected from the endophilic environment. The percentage occurrence, total dstribution ...

  8. Dynamics of an ant-plant-pollinator model

    Science.gov (United States)

    Wang, Yuanshi; DeAngelis, Donald L.; Nathaniel Holland, J.

    2015-03-01

    In this paper, we consider plant-pollinator-ant systems in which plant-pollinator interaction and plant-ant interaction are both mutualistic, but there also exists interference of pollinators by ants. The plant-pollinator interaction can be described by a Beddington-DeAngelis formula, so we extend the formula to characterize plant-pollinator mutualisms, including the interference by ants, and form a plant-pollinator-ant model. Using dynamical systems theory, we show uniform persistence of the model. Moreover, we demonstrate conditions under which boundary equilibria are globally asymptotically stable. The dynamics exhibit mechanisms by which the three species could coexist when ants interfere with pollinators. We define a threshold in ant interference. When ant interference is strong, it can drive plant-pollinator mutualisms to extinction. Furthermore, if the ants depend on pollination mutualism for their persistence, then sufficiently strong ant interference could lead to their own extinction as well. Yet, when ant interference is weak, plant-ant and plant-pollinator mutualisms can promote the persistence of one another.

  9. Ants Orasest ja Anne Lange monograafiast / Jüri Talvet

    Index Scriptorium Estoniae

    Talvet, Jüri, 1945-

    2005-01-01

    Arvustus: Oras, Ants. Luulekool. I, Apoloogia / koostajad Hando Runnel ja Jaak Rähesoo. Tartu : Ilmamaa, 2003 ; Oras, Ants. Luulekool II, Meistriklass. Tartu : Ilmamaa, 2004 ; Lange, Anne. Ants Oras : [kirjandusteadlane, -kriitik ja tõlkija (1900-1982)]. Tartu : Ilmamaa, 2004

  10. Clima motivacional, competencia percibida, compromiso y ansiedad en Educación Física. Diferencias en función de la obligatoriedad de la enseñanza

    Directory of Open Access Journals (Sweden)

    Javier Coter\\u00F3n L\\u00F3pez

    2013-01-01

    Full Text Available Este estudio describe las relaciones entre el clima motivacional percibido, la competencia percibida, el compromiso y la ansiedad en una muestra estudiantes de educación física y analiza las diferencias mostradas en estas variables según la obligatoriedad o no de la enseñanza. 1587 alumnos de edades comprendidas entre 12 y 18 años (M = 15.26 años; DE = 1.61 completaron las adaptaciones españolas del PMCSQ-2 (Perceived Motivational Climate in Sport Questionaire-2 y del AMPET (Achievement Motivation in Physical Education Test. Los resultados mostraron diferencias según la obligatoriedad de la enseñanza en la variable ansiedad, en la que los estudiantes de estudios obligatorios obtuvieron puntuaciones superiores que los estudiantes de estudios post-obligatorios. Los análisis correlacionales y de regresión mostraron mayor consistencia entre estudiantes de bachillerato que de enseñanza secundaria obligatoria (ESO, encontrándose que un clima ego era el mejor predictor de la competencia percibida y la ansiedad; mientras que un clima orientado a la tarea lo era del compromiso. Los resultados sugieren que el carácter de la enseñanza puede ser una variable a considerar en el estudio del perfil motivacional de los alumnos.

  11. Are ant feces nutrients for plants? A metabolomics approach to elucidate the nutritional effects on plants hosting weaver ants

    DEFF Research Database (Denmark)

    Vidkjær, Nanna Hjort; Wollenweber, Bernd; Gislum, René

    2015-01-01

    Weaver ants (genus Oecophylla) are tropical carnivorous ant species living in high numbers in the canopies of trees. The ants excrete copious amounts of fecal matter on leaf surfaces, and these feces may provide nutrients to host trees. This hypothesis is supported by studies of ant......-plant interactions involving other ant species that have demonstrated the transfer of nutrients from ants to plants. In this 7-months study, a GC–MS-based metabolomics approach along with an analysis of total nitrogen and carbon levels was used to study metabolic changes in ant-hosting Coffea arabica plants compared...... with control plants. The results showed elevated levels of total nitrogen, amino acids, fatty acids, caffeine, and secondary metabolites of the phenylpropanoid pathway in leaves from ant-hosting plants. Minor effects were observed for sugars, whereas little or no effect was observed for organic acids, despite...

  12. Plant lock and ant key: pairwise coevolution of an exclusion filter in an ant-plant mutualism.

    Science.gov (United States)

    Brouat, C; Garcia, N; Andary, C; McKey, D

    2001-10-22

    Although observations suggest pairwise coevolution in specific ant-plant symbioses, coevolutionary processes have rarely been demonstrated. We report on, what is to the authors' knowledge, the strongest evidence yet for reciprocal adaptation of morphological characters in a species-specific ant-plant mutualism. The plant character is the prostoma, which is a small unlignified organ at the apex of the domatia in which symbiotic ants excavate an entrance hole. Each myrmecophyte in the genus Leonardoxa has evolved a prostoma with a different shape. By performing precise measurements on the prostomata of three related myrmecophytes, on their specific associated ants and on the entrance holes excavated by symbiotic ants at the prostomata, we showed that correspondence of the plant and ant traits forms a morphological and behavioural filter. We have strong evidence for coevolution between the dimensions and shape of the symbiotic ants and the prostoma in one of the three ant-Leonardoxa associations.

  13. Discursos em disputa: uma leitura alternativa acerca dos dilemas da ação internacional na Somália durante a década de 1990

    Directory of Open Access Journals (Sweden)

    Marta Regina Fernandez Y Garcia Moreno

    2014-01-01

    Full Text Available O artigo aborda os dilemas enfrentados pelos atores internacionais nas operações de paz levadas a cabo na Somália na década de 1990. Busca-se evidenciar as narrativas divergentes articuladas pelos Estados Unidos e pelas Nações Unidas vis-à-vis o "Outro" somali. Sugere-se que os principais dilemas experimentados pela ONU e pelos Estados Unidos na Somália não foram de natureza técnica, concernente a problemas de coordenação entre as principais forças envolvidas, como usualmente se argumenta. Diferentemente, argumenta-se que existiu uma disputa de natureza política entre os Estados Unidos e a ONU na Somália, amparada por discursos distintos sobre o "Outro" somali.

  14. El dilema del jugador

    Directory of Open Access Journals (Sweden)

    Alberto Murcia

    2018-05-01

    Full Text Available Why we are entitled to negative moral judgments when someone is playing games about child pornography, but this is not the case when someone acts as a fictional killer? Some moral standpoint claims that seem wrong uttering moral judgments to someone while the fiction is not transfer to reality by that person. But this is insufficient: even without committing real damage moral awkwardness remains. This paper approaches this topic from another standpoint to normative ethics o cultural relativism. I analyze how emotions adjustment or follow a command are conditions which we use to avoid or prescribe moral judgments.

  15. Interactive effects of soil-dwelling ants, ant mounds and simulated grazing on local plant community composition

    NARCIS (Netherlands)

    Veen, G.F.; Olff, H.

    2011-01-01

    Interactions between aboveground vertebrate herbivores and subterranean yellow meadow ants (Lasius flavus) can drive plant community patterns in grassland ecosystems. Here, we study the relative importance of the presence of ants (L. flavus) and ant mounds under different simulated grazing regimes

  16. Edge detection in digital images using Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    Marjan Kuchaki Rafsanjani

    2015-11-01

    Full Text Available Ant Colony Optimization (ACO is an optimization algorithm inspired by the behavior of real ant colonies to approximate the solutions of difficult optimization problems. In this paper, ACO is introduced to tackle the image edge detection problem. The proposed approach is based on the distribution of ants on an image; ants try to find possible edges by using a state transition function. Experimental results show that the proposed method compared to standard edge detectors is less sensitive to Gaussian noise and gives finer details and thinner edges when compared to earlier ant-based approaches.

  17. The Pied Piper: A Parasitic Beetle's Melodies Modulate Ant Behaviours.

    Directory of Open Access Journals (Sweden)

    Andrea Di Giulio

    Full Text Available Ants use various communication channels to regulate their social organisation. The main channel that drives almost all the ants' activities and behaviours is the chemical one, but it is long acknowledged that the acoustic channel also plays an important role. However, very little is known regarding exploitation of the acoustical channel by myrmecophile parasites to infiltrate the ant society. Among social parasites, the ant nest beetles (Paussus are obligate myrmecophiles able to move throughout the colony at will and prey on the ants, surprisingly never eliciting aggression from the colonies. It has been recently postulated that stridulatory organs in Paussus might be evolved as an acoustic mechanism to interact with ants. Here, we survey the role of acoustic signals employed in the Paussus beetle-Pheidole ant system. Ants parasitised by Paussus beetles produce caste-specific stridulations. We found that Paussus can "speak" three different "languages", each similar to sounds produced by different ant castes (workers, soldiers, queen. Playback experiments were used to test how host ants respond to the sounds emitted by Paussus. Our data suggest that, by mimicking the stridulations of the queen, Paussus is able to dupe the workers of its host and to be treated as royalty. This is the first report of acoustic mimicry in a beetle parasite of ants.

  18. The interactions of ants with their biotic environment.

    Science.gov (United States)

    Chomicki, Guillaume; Renner, Susanne S

    2017-03-15

    This s pecial feature results from the symposium 'Ants 2016: ant interactions with their biotic environments' held in Munich in May 2016 and deals with the interactions between ants and other insects, plants, microbes and fungi, studied at micro- and macroevolutionary levels with a wide range of approaches, from field ecology to next-generation sequencing, chemical ecology and molecular genetics. In this paper, we review key aspects of these biotic interactions to provide background information for the papers of this s pecial feature After listing the major types of biotic interactions that ants engage in, we present a brief overview of ant/ant communication, ant/plant interactions, ant/fungus symbioses, and recent insights about ants and their endosymbionts. Using a large molecular clock-dated Formicidae phylogeny, we map the evolutionary origins of different ant clades' interactions with plants, fungi and hemiptera. Ants' biotic interactions provide ideal systems to address fundamental ecological and evolutionary questions about mutualism, coevolution, adaptation and animal communication. © 2017 The Author(s).

  19. Ant species confer different partner benefits on two neotropical myrmecophytes.

    Science.gov (United States)

    Frederickson, Megan E

    2005-04-01

    The dynamics of mutualistic interactions involving more than a single pair of species depend on the relative costs and benefits of interaction among alternative partners. The neotropical myrmecophytes Cordia nodosa and Duroia hirsuta associate with several species of obligately symbiotic ants. I compared the ant partners of Cordia and Duroia with respect to two benefits known to be important in ant-myrmecophyte interactions: protection against herbivores provided by ants, and protection against encroaching vegetation provided by ants. Azteca spp., Myrmelachista schumanni, and Allomerus octoarticulatus demerarae ants all provide the leaves of Cordia and Duroia some protection against herbivores. However, Azteca and Allomerus provide more protection than does Myrmelachista to the leaves of their host plants. Although Allomerus protects the leaves of its hosts, plants occupied by Allomerus suffer more attacks by herbivores to their stems than do plants occupied by other ants. Relative to Azteca or Allomerus, Myrmelachista ants provide better protection against encroaching vegetation, increasing canopy openness over their host plants. These differences in benefits among the ant partners of Cordia and Duroia are reflected in the effect of each ant species on host plant size, growth rate, and reproduction. The results of this study show how mutualistic ant partners can differ with respect to both the magnitude and type of benefits they provide to the same species of myrmecophytic host.

  20. Fast and flexible: argentine ants recruit from nearby trails.

    Directory of Open Access Journals (Sweden)

    Tatiana P Flanagan

    Full Text Available Argentine ants (Linepithema humile live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  1. Host ant independent oviposition in the parasitic butterfly Maculinea alcon

    DEFF Research Database (Denmark)

    Fürst, Matthias A; Nash, David Richard

    2010-01-01

    to host-ant nests and non-host-ant nests, and the number and position of eggs attached were assessed. Our results show no evidence for host-ant-based oviposition in M. alcon, but support an oviposition strategy based on plant characteristics. This suggests that careful management of host-ant distribution......Parasitic Maculinea alcon butterflies can only develop in nests of a subset of available Myrmica ant species, so female butterflies have been hypothesized to preferentially lay eggs on plants close to colonies of the correct host ants. Previous correlational investigations of host......-ant-dependent oviposition in this and other Maculinea species have, however, shown equivocal results, leading to a long-term controversy over support for this hypothesis. We therefore conducted a controlled field experiment to study the egg-laying behaviour of M. alcon. Matched potted Gentiana plants were set out close...

  2. Exploring with PAM: Prospecting ANTS Missions for Solar System Surveys

    Science.gov (United States)

    Clark, P. E.; Rilee, M. L.; Curtis, S. A.

    2003-01-01

    ANTS (Autonomous Nano-Technology Swarm), a large (1000 member) swarm of nano to picoclass (10 to 1 kg) totally autonomous spacecraft, are being developed as a NASA advanced mission concept. ANTS, based on a hierarchical insect social order, use an evolvable, self-similar, hierarchical neural system in which individual spacecraft represent the highest level nodes. ANTS uses swarm intelligence attained through collective, cooperative interactions of the nodes at all levels of the system. At the highest levels this can take the form of cooperative, collective behavior among the individual spacecraft in a very large constellation. The ANTS neural architecture is designed for totally autonomous operation of complex systems including spacecraft constellations. The ANTS (Autonomous Nano Technology Swarm) concept has a number of possible applications. A version of ANTS designed for surveying and determining the resource potential of the asteroid belt, called PAM (Prospecting ANTS Mission), is examined here.

  3. Fast and flexible: argentine ants recruit from nearby trails.

    Science.gov (United States)

    Flanagan, Tatiana P; Pinter-Wollman, Noa M; Moses, Melanie E; Gordon, Deborah M

    2013-01-01

    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  4. Using pleometrosis (multiple queens) and pupae transplantation to boost weaver ant (Oecophylla smaragdina) colony growth in ant nurseries

    DEFF Research Database (Denmark)

    Offenberg, Hans Joachim; Nielsen, Mogens Gissel; Peng, Renkang

    2011-01-01

    Weaver ants (Oecophylla spp.) are increasingly being used for biocontrol and are targeted for future production of insect protein in ant farms. An efficient production of live ant colonies may facilitate the utilization of these ants but the production of mature colonies is hampered by the long...... and no transplantation. Thus, in ant nurseries the use of multiple queens during nest founding as well as transplantation of pupae from foreign colonies may be utilised to decrease the time it takes to produce a colony ready for implementation....

  5. Optic disc detection using ant colony optimization

    Science.gov (United States)

    Dias, Marcy A.; Monteiro, Fernando C.

    2012-09-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

  6. A global database of ant species abundances

    Czech Academy of Sciences Publication Activity Database

    Gibb, H.; Dunn, R. R.; Sanders, N. J.; Grossman, B. F.; Photakis, M.; Abril, S.; Agosti, D.; Andersen, A. N.; Angulo, E.; Armbrecht, I.; Arnan, X.; Baccaro, F. B.; Bishop, T. R.; Boulay, R.; Brühl, C.; Castracani, C.; Cerdá, X.; Del Toro, I.; Delsinne, T.; Diaz, M.; Donoso, D. A.; Ellison, A. M.; Enríquez, M. L.; Fayle, Tom Maurice; Feener, D. H.; Fisher, B. L.; Fisher, R. N.; Fitzpatrick, M. C.; Gómez, C.; Gotelli, N. J.; Gove, A.; Grasso, D. A.; Groc, S.; Guenard, B.; Gunawardene, N.; Heterick, B.; Hoffmann, B.; Janda, Milan; Jenkins, C.; Kaspari, M.; Klimeš, Petr; Lach, L.; Laeger, T.; Lattke, J.; Leponce, M.; Lessard, J.-P.; Longino, J.; Lucky, A.; Luke, S. H.; Majer, J.; McGlynn, T. P.; Menke, S.; Mezger, D.; Mori, A.; Moses, Jimmy; Munyai, T. C.; Pacheco, R.; Paknia, O.; Pearce-Duvet, J.; Pfeiffer, M.; Philpott, S. M.; Resasco, J.; Retana, J.; Silva, R. R.; Sorger, M. D.; Souza, J.; Suarez, A.; Tista, M.; Vasconcelos, H. L.; Vonshak, M.; Weisser, M. D.; Yates, M.; Parr, C. L.

    2017-01-01

    Roč. 98, č. 3 (2017), s. 883-884 ISSN 0012-9658 R&D Projects: GA ČR GB14-36098G; GA ČR GAP505/12/2467; GA ČR GPP505/12/P875 Institutional support: RVO:60077344 Keywords : abundance * ants * database Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.809, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/ecy.1682/abstract

  7. Public goods dilemma in asexual ant societies

    OpenAIRE

    Dobata, Shigeto; Tsuji, Kazuki

    2013-01-01

    This study reports experimental evidence for the “public goods dilemma” between cooperators and cheaters in an asexual ant society, in which cheating is always more rewarding for individuals but cooperation at the cost of individual fitness leads to better performance of groups. Although this dilemma provides the basic principle of social evolution, its experimental demonstration with underlying genetics and fitness evaluation for both cooperators and cheaters still lacks in societies other t...

  8. Ant colony optimization and constraint programming

    CERN Document Server

    Solnon, Christine

    2013-01-01

    Ant colony optimization is a metaheuristic which has been successfully applied to a wide range of combinatorial optimization problems. The author describes this metaheuristic and studies its efficiency for solving some hard combinatorial problems, with a specific focus on constraint programming. The text is organized into three parts. The first part introduces constraint programming, which provides high level features to declaratively model problems by means of constraints. It describes the main existing approaches for solving constraint satisfaction problems, including complete tree search

  9. Precision Rescue Behavior in North American Ants

    Directory of Open Access Journals (Sweden)

    Katherine Taylor

    2013-07-01

    Full Text Available Altruistic behavior, in which one individual provides aid to another at some cost to itself, is well documented. However, some species engage in a form of altruism, called rescue, that places the altruist in immediate danger. Here we investigate one such example, namely rescuing victims captured by predators. In a field experiment with two North American ant species, Tetramorium sp. E and Prenolepis imparis, individuals were held in artificial snares simulating capture. T. sp. E, but not P. imparis, exhibited digging, pulling, and snare biting, the latter precisely targeted to the object binding the victim. These results are the first to document precision rescue in a North American ant species; moreover, unlike rescue in other ants, T. sp. E rescues conspecifics from different colonies, mirroring their atypical social behavior, namely the lack of aggression between non-nestmate (heterocolonial conspecifics. In a second, observational study designed to demonstrate rescue from an actual predator, T. sp. E victims were dropped into an antlion's pit and the behavior of a single rescuer was observed. Results showed that T. sp. E not only attempted to release the victim, but also risked attacking the predator, suggesting that precision rescue may play an important role in this species' antipredator behavior.

  10. Recognition of social identity in ants

    Directory of Open Access Journals (Sweden)

    Nick eBos

    2012-03-01

    Full Text Available Recognizing the identity of others, from the individual to the group level, is a hallmark of society. Ants, and other social insects, have evolved advanced societies characterized by efficient social recognition systems. Colony identity is mediated by colony specific signature mixtures, a blend of hydrocarbons present on the cuticle of every individual (the label. Recognition occurs when an ant encounters another individual, and compares the label it perceives to an internal representation of its own colony odor (the template. A mismatch between label and template leads to rejection of the encountered individual. Although advances have been made in our understanding of how the label is produced and acquired, contradictory evidence exists about information processing of recognition cues. Here, we review the literature on template acquisition in ants and address how and when the template is formed, where in the nervous system it is localized, and the possible role of learning. We combine seemingly contradictory evidence in to a novel, parsimonious theory for the information processing of nestmate recognition cues.

  11. The invasive ant, Solenopsis invicta, reduces herpetofauna richness and abundance

    Science.gov (United States)

    Allen, Craig R.; Birge, Hannah E.; Slater, J.; Wiggers, E.

    2017-01-01

    Amphibians and reptiles are declining globally. One potential cause of this decline includes impacts resulting from co-occurrence with non-native red imported fire ant, Solenopsis invicta. Although a growing body of anecdotal and observational evidence from laboratory experiments supports this hypothesis, there remains a lack of field scale manipulations testing the effect of fire ants on reptile and amphibian communities. We addressed this gap by measuring reptile and amphibian (“herpetofauna”) community response to successful fire ant reductions over the course of 2 years following hydramethylnon application to five 100–200 ha plots in southeastern coastal South Carolina. By assessing changes in relative abundance and species richness of herpetofauna in response to fire ant reductions, we were able to assess whether some species were particularly vulnerable to fire ant presence, and whether this sensitivity manifested at the community level. We found that herpetofauna abundance and species richness responded positively to fire ant reductions. Our results document that even moderate populations of red imported fire ants decrease both the abundance and diversity of herpetofauna. Given global herpetofauna population declines and continued spread of fire ants, there is urgency to understand the impacts of fire ants beyond anecdotal and singles species studies. Our results provides the first community level investigation addressing these dynamics, by manipulating fire ant abundance to reveal a response in herpetofauna species abundance and richness.

  12. Predaceous ants, beach replenishment, and nest placement by sea turtles.

    Science.gov (United States)

    Wetterer, James K; Wood, Lawrence D; Johnson, Chris; Krahe, Holly; Fitchett, Stephanie

    2007-10-01

    Ants known for attacking and killing hatchling birds and reptiles include the red imported fire ant (Solenopsis invicta Buren), tropical fire ant [Solenopsis geminata (Fabr.)], and little fire ant [Wasmannia auropunctata (Roger)]. We tested whether sea turtle nest placement influenced exposure to predaceous ants. In 2000 and 2001, we surveyed ants along a Florida beach where green turtles (Chelonia mydas L.), leatherbacks (Dermochelys coriacea Vandelli), and loggerheads (Caretta caretta L.) nest. Part of the beach was artificially replenished between our two surveys. As a result, mean beach width experienced by nesting turtles differed greatly between the two nesting seasons. We surveyed 1,548 sea turtle nests (2000: 909 nests; 2001: 639 nests) and found 22 ant species. S. invicta was by far the most common species (on 431 nests); S. geminata and W. auropunctata were uncommon (on 3 and 16 nests, respectively). In 2000, 62.5% of nests had ants present (35.9% with S. invicta), but in 2001, only 30.5% of the nests had ants present (16.4% with S. invicta). Turtle nests closer to dune vegetation had significantly greater exposure to ants. Differences in ant presence on turtle nests between years and among turtle species were closely related to differences in nest placement relative to dune vegetation. Beach replenishment significantly lowered exposure of nests to ants because on the wider beaches turtles nested farther from the dune vegetation. Selective pressures on nesting sea turtles are altered both by the presence of predaceous ants and the practice of beach replenishment.

  13. Chemically armed mercenary ants protect fungus-farming societies

    Science.gov (United States)

    Adams, Rachelle M. M.; Liberti, Joanito; Illum, Anders A.; Jones, Tappey H.; Nash, David R.; Boomsma, Jacobus J.

    2013-01-01

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies. PMID:24019482

  14. Chemically armed mercenary ants protect fungus-farming societies.

    Science.gov (United States)

    Adams, Rachelle M M; Liberti, Joanito; Illum, Anders A; Jones, Tappey H; Nash, David R; Boomsma, Jacobus J

    2013-09-24

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies.

  15. When invasive ants meet: effects of outbreeding on queen performance in the tramp ant Cardiocondyla itsukii.

    Science.gov (United States)

    Heinze, Jürgen; Frohschammer, Sabine; Bernadou, Abel

    2017-08-18

    Most disturbed habitats in the tropics and subtropics harbor numerous species of invasive ants, and occasionally the same species has been introduced repeatedly from multiple geographical sources. We examined how experimental crossbreeding between sexuals from different populations affects the fitness of queens of the tramp ant Cardiocondyla itsukii, which is widely distributed in Asia and the Pacific Islands. Eggs laid by queens that mated with nestmate males had a higher hatching rate than eggs laid by queens mated to males from neighboring (Hawaii × Kauai) or distant introduced populations (Hawaii/Kauai × Okinawa). Furthermore, inbreeding queens had a longer lifespan and produced a less female-biased offspring sex ratio than queens from allopatric mating. This suggests that the genetic divergence between different source populations may already be so large that in case of multiple invasions eventual crossbreeding might negatively affect the fitness of tramp ants. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  16. Food source quality and ant dominance hierarchy influence the outcomes of ant-plant interactions in an arid environment

    Science.gov (United States)

    Flores-Flores, Rocío Vianey; Aguirre, Armando; Anjos, Diego V.; Neves, Frederico S.; Campos, Ricardo I.; Dáttilo, Wesley

    2018-02-01

    In this study, we conducted a series of experiments in a population of Vachellia constricta (Fabaceae) in the arid Tehuacan-Cuicatláan valley, Mexico, in order to evaluate if the food source quality and ant dominance hierarchy influence the outcomes of ant-plant interactions. Using an experiment with artificial nectaries, we observed that ants foraging on food sources with higher concentration of sugar are quicker in finding and attacking potential herbivorous insects. More specifically, we found that the same ant species may increase their defence effectiveness according to the quality of food available. These findings indicate that ant effectiveness in plant protection is context-dependent and may vary according to specific individual characteristics of plants. In addition, we showed that competitively superior ant species tend to dominate plants in periods with high nectar activity, emphasizing the role of the dominance hierarchy structuring ant-plant interactions. However, when high sugar food sources were experimentally available ad libitum, the nocturnal and competitively superior ant species, Camponotus atriceps, did not dominate the artificial nectaries during the day possibly due to limitation of its thermal tolerance. Therefore, temporal niche partitioning may be allowing the coexistence of two dominant ant species (Camponotus rubritorax during the day and C. atriceps at night) on V. constricta. Our findings indicate that the quality of the food source, and temporal shifts in ant dominance are key factors which structure the biotic plant defences in an arid environment.

  17. Just follow your nose: homing by olfactory cues in ants.

    Science.gov (United States)

    Steck, Kathrin

    2012-04-01

    How is an ant-equipped with a brain that barely exceeds the size of a pinhead-capable of achieving navigational marvels? Even though evidences suggest that navigation is a multimodal process, ants heavily depend on olfactory cues-of pheromonal and non-pheromonal nature-for foraging and orientation. Recent studies have directed their attention to the efficiency of pheromone trail networks. Advances in neurophysiological techniques make it possible to investigate trail pheromone processing in the ant's brain. In addition to relying on pheromone odours, ants also make use of volatiles emanating from the nest surroundings. Deposited in the vicinity of the nest, these home-range markings help the ants to home after a foraging run. Furthermore, olfactory landmarks associated with the nest enhance ants' homing abilities. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Ant tending influences soldier production in a social aphid.

    Science.gov (United States)

    Shingleton, A W; Foster, W A

    2000-09-22

    The aphid Pseudoregma sundanica (Van der Goot) (Homoptera: Aphididae) has two defence strategies. It is obligatorily tended by various species of ant and also produces sterile soldiers. We investigated how they allocate their investment in these two strategies. We measured the size, number of soldiers, number and species of tending ant, and number and species of predators in P. sundanica populations. We found that the level of ant tending correlated negatively with soldier investment in P. sundanica. The species of tending ant also influenced soldier investment. We excluded ants from aphid populations and recorded changes in population size and structure over four weeks. Ant exclusion led to population decline and extinction. At the same time, surviving populations showed a significant increase in soldier investment. The data demonstrate that social aphids can adjust their investment in soldiers in direct response to environmental change.

  19. Una exploración de las posturas filosóficas del personal operativo de servicios de atención a la salud ante dilemas bioéticos: ciudad de México

    Directory of Open Access Journals (Sweden)

    Sergio López Moreno

    2012-12-01

    Full Text Available En la actualidad las instituciones de salud tienen como objetivo vigilar y promover el compromiso de respeto a los derechos de los pacientes, pero muchos de los problemas éticos-clínicos no provienen directamente de la relaciona profesional de la salud-paciente, sino de otros dos factores importantes: los problemas institucionales y los problemas éticos planteados por las políticas y sistemas de salud.

  20. Consuming fire ants reduces northern bobwhite survival and weight gain

    Science.gov (United States)

    Myers, P.E.; Allen, Craig R.; Birge, Hannah E.

    2014-01-01

    Northern bobwhite quail, Colinus virginianus (L.) (Galliformes: Odontophoridae), population declines are well documented, but pinpointing the reasons for these decreases has proven elusive. Bobwhite population declines are attributed primarily to loss of habitat and land use changes. This, however, does not entirely explain population declines in areas intensively managed for bobwhites. Although previous research demonstrates the negative impact of red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) on northern bobwhites, the mechanisms underlying this effect are largely unknown. To meet the protein demands of early growth and development, bobwhite chicks predominantly consume small insects, of which ants are a substantial proportion. Fire ants alter ant community dynamics by often reducing native ant diversity and abundance while concurrently increasing the abundance of individuals. Fire ants have negative effects on chicks, but they are also a large potential protein source, making it difficult to disentangle their net effect on bobwhite chicks. To help investigate these effects, we conducted a laboratory experiment to understand (1) whether or not bobwhites consume fire ants, and (2) how the benefits of this consumption compare to the deleterious impacts of bobwhite chick exposure to fire ants. Sixty bobwhite chicks were separated into two groups of 30; one group was provided with starter feed only and the second group was provided with feed and fire ants. Bobwhite chicks were observed feeding on fire ants. Chicks that fed on fire ants had reduced survival and weight gain. Our results show that, while fire ants increase potential food sources for northern bobwhite, their net effect on bobwhite chicks is deleterious. This information will help inform land managers and commercial bobwhite rearing operations.

  1. Cercomacra and related antbirds (Aves, Formicariidae as army ant followers

    Directory of Open Access Journals (Sweden)

    Edwin O. Willis

    1984-01-01

    Full Text Available Cercomacra and Schistocichla antbirds (Formicariidae favor dense foliage and seldom follow army ants for flushed prey, since the ants move through open forest understory as well as through dense zones. Two other lineages, the Drymophila-Hypocnemis lineage (of dense woodland understory and the Formicivora lineage (of dense bushes in dry or semiopen zones, also cannot follow ants regularly through open forest understory.

  2. Do herbivores eavesdrop on ant chemical communication to avoid predation?

    Directory of Open Access Journals (Sweden)

    David J Gonthier

    Full Text Available Strong effects of predator chemical cues on prey are common in aquatic and marine ecosystems, but are thought to be rare in terrestrial systems and specifically for arthropods. For ants, herbivores are hypothesized to eavesdrop on ant chemical communication and thereby avoid predation or confrontation. Here I tested the effect of ant chemical cues on herbivore choice and herbivory. Using Margaridisa sp. flea beetles and leaves from the host tree (Conostegia xalapensis, I performed paired-leaf choice feeding experiments. Coating leaves with crushed ant liquids (Azteca instabilis, exposing leaves to ant patrolling prior to choice tests (A. instabilis and Camponotus textor and comparing leaves from trees with and without A. instabilis nests resulted in more herbivores and herbivory on control (no ant-treatment relative to ant-treatment leaves. In contrast to A. instabilis and C. textor, leaves previously patrolled by Solenopsis geminata had no difference in beetle number and damage compared to control leaves. Altering the time A. instabilis patrolled treatment leaves prior to choice tests (0-, 5-, 30-, 90-, 180-min. revealed treatment effects were only statistically significant after 90- and 180-min. of prior leaf exposure. This study suggests, for two ecologically important and taxonomically diverse genera (Azteca and Camponotus, ant chemical cues have important effects on herbivores and that these effects may be widespread across the ant family. It suggests that the effect of chemical cues on herbivores may only appear after substantial previous ant activity has occurred on plant tissues. Furthermore, it supports the hypothesis that herbivores use ant chemical communication to avoid predation or confrontation with ants.

  3. A Theoretic Basis for IS? The Contribution of ANT

    Directory of Open Access Journals (Sweden)

    Jim Underwood

    2002-11-01

    Full Text Available Representation is a key issue of IS design and operation that is often ignored. Actor-network theory (ANT, a semiotic theory of stakeholders, provides a way of dealing with representation. Combining aspects of ANT and Foucault's discourse theory allows us to include concepts as actors and promises a flexible and durable foundation for IS practice, but ANT itself indicates that the search for a purely theoretical foundation for IS is misguided.

  4. Posicionamento de médicos residentes frente a dilemas éticos com pacientes pediátricos = Attitudes of residents cancerning ethical dilemmas with pediatric patients

    Directory of Open Access Journals (Sweden)

    Chiapin, Maria Luísa

    2005-01-01

    Conclusão: Depois de um ano de programa de residência médica houve modificação na atitudes dos médicos residentes em relação aos dilemas éticos de pacientes pediátricos, independente de qualquer treinamento específico ou discussão formal de aspectos da bioética. Uma concordância moderada foi detectada entre os homens e a questões relativas ao princípio da justiça. Houve também uma associação positiva entre a tendência de endereçar critérios de necessidade relacionadas ao princípio da justiça e o sexo feminino, na área pediátrica. É importante que medidas bioéticas educativas sejam implementadas durante a residência em pediatria

  5. REFLEXIONES EN TORNO A LOS DILEMAS ÉTICOS Y LA POSTURA POLÍTICA DE LAS Y LOS TRABAJADORES SOCIALES EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Uva Falla Ramírez

    2012-01-01

    Full Text Available El artículo trae reflexiones acerca del modelo neoliberal, lo que ha llevado a un mayor deterioro de las condiciones sociales de la población colombiana; el desarrollo se ha centrado en el crecimiento económico, en detrimento de la calidad de vida de la población. De esta manera, la generación de más pobreza ha sido una constante, donde las políticas sociales se dirigen a la población más vulnerable, convirtiéndose en instrumento de mercantilización y privatización de los derechos. Destaca que es en ese contexto que los y las trabajadoras sociales centran su quehacer, en su mayoría como ejecutores de dichas políticas, donde viven una serie de contradicciones provenientes de la dinámica de las instituciones, de los sujetos sociales y de su propia condición de sujeto social. Concluye que esto les genera unos dilemas en la actuación, que se mueven en el plano de lo ético, pero que, finalmente, se resuelven al trascender en la construcción de un proyecto político.

  6. Prácticas de argumentación en una comunidad de terapeutas: la construcción de un dilema

    Directory of Open Access Journals (Sweden)

    Alexis Ibarra Martínez

    2014-09-01

    Full Text Available Esta investigación adopta una perspectiva discursiva que se centra en la producción de argumentos en la interacción. La premisa es que las personas constituyen su realidad social a través del uso activo del lenguaje. El corpus de datos está conformado por las grabaciones de los encuentros entre terapeutas que reflexionan sobre su práctica clínica. Las descripciones que las terapeutas formulan sobre su trabajo pueden separarse en una postura que ellas denominan "colaborativa" y otra que llaman "directiva". El foco de análisis son las formas argumentación que ellas producen para justificar o criticar cada una de estas posturas. Las terapeutas abogan a favor de una postura colaborativa, aún así consideran tomar posiciones directivas a pesar de que representa una contradicción con sus valores. Las terapeutas resuelven esta oposición con argumentos: justifican la adopción de una postura directiva al mismo tiempo que reconocen que es indeseable. Estos hallazgos se analizan a partir de la noción de dilema como una construcción retórica que posibilita y constriñe las formas de pensamiento de una comunidad. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1403230

  7. A esquerda ontem e hoje: o dilema entre igualdade e liberdade The Left of yesterday and of today: the dilemma between equality and freedom

    Directory of Open Access Journals (Sweden)

    Maria Francisca Pinheiro Coelho

    2009-08-01

    Full Text Available Este artigo discorre sobre as idéias da Esquerda na década de 1960 e as mudanças de paradigmas a partir da década de 1990, após a queda do Muro de Berlim e o colapso do socialismo real. Aborda um conflito que perpassa a história do socialismo: a questão dos direitos civis. Analisa também os dilemas da esquerda ontem e hoje, com ênfase na relação entre política e liberdade. Sugere que concomitante com a defesa da justiça social, a identidade de uma esquerda contemporânea se define pela defesa da liberdade como valor fundamental e essência da política.This article deals with the ideas of the Left in the 1960's and the changes in leftist ideas and politics in the 1990's, after the collapse of the Berlin Wall and the demise of socialism. It focuses on a conflict that has been present in the history of socialism: the question o civil rights. The article also analyzes the dilemmas of the Left of yesterday and of today, with an emphasis on the relationship between politics and freedom. It suggests that concomitant with the defense of social justice, the identity of the contemporary Left is largely defined by the defense of freedom as a fundamental value and the very essence of politics.

  8. Insecticide transfer efficiency and lethal load in Argentine ants

    Energy Technology Data Exchange (ETDEWEB)

    Hooper-Bui, L.M. [Department of Environmental Science, Louisiana State University, Baton Rouge, LA 70803 (United States); Department of Entomology, University of California, Riverside, CA 92521 (United States); Kwok, E.S.C. [Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521 (United States); Buchholz, B.A., E-mail: buchholz2@llnl.gov [Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Rust, M.K. [Department of Entomology, University of California, Riverside, CA 92521 (United States); Eastmond, D.A. [Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521 (United States); Vogel, J.S. [Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States)

    2015-10-15

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of {sup 14}C-sucrose, {sup 14}C-hydramethylnon, and {sup 14}C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  9. Improved Ant Colony Clustering Algorithm and Its Performance Study

    Science.gov (United States)

    Gao, Wei

    2016-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational efficiency and accuracy of the ant colony clustering algorithm. The abstraction ant colony clustering algorithm is used to cluster benchmark problems, and its performance is compared with the ant colony clustering algorithm and other methods used in existing literature. Based on similar computational difficulties and complexities, the results show that the abstraction ant colony clustering algorithm produces results that are not only more accurate but also more efficiently determined than the ant colony clustering algorithm and the other methods. Thus, the abstraction ant colony clustering algorithm can be used for efficient multivariate data clustering. PMID:26839533

  10. Insecticide transfer efficiency and lethal load in Argentine ants

    International Nuclear Information System (INIS)

    Hooper-Bui, L.M.; Kwok, E.S.C.; Buchholz, B.A.; Rust, M.K.; Eastmond, D.A.; Vogel, J.S.

    2015-01-01

    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14 C-sucrose, 14 C-hydramethylnon, and 14 C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  11. Disease dynamics in a specialized parasite of ant societies

    DEFF Research Database (Denmark)

    Andersen, Sandra Breum; Ferrari, Matthew; Evans, Harry C.

    2012-01-01

    Coevolution between ant colonies and their rare specialized parasites are intriguing, because lethal infections of workers may correspond to tolerable chronic diseases of colonies, but the parasite adaptations that allow stable coexistence with ants are virtually unknown. We explore the trade......-offs experienced by Ophiocordyceps parasites manipulating ants into dying in nearby graveyards. We used field data from Brazil and Thailand to parameterize and fit a model for the growth rate of graveyards. We show that parasite pressure is much lower than the abundance of ant cadavers suggests...

  12. Signals can trump rewards in attracting seed-dispersing ants.

    Directory of Open Access Journals (Sweden)

    Kyle M Turner

    Full Text Available Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds.

  13. The evolution of invasiveness in garden ants.

    Directory of Open Access Journals (Sweden)

    Sylvia Cremer

    Full Text Available It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects.

  14. The Evolution of Invasiveness in Garden Ants

    Science.gov (United States)

    Cremer, Sylvia; Ugelvig, Line V.; Drijfhout, Falko P.; Schlick-Steiner, Birgit C.; Steiner, Florian M.; Seifert, Bernhard; Hughes, David P.; Schulz, Andreas; Petersen, Klaus S.; Konrad, Heino; Stauffer, Christian; Kiran, Kadri; Espadaler, Xavier; d'Ettorre, Patrizia; Aktaç, Nihat; Eilenberg, Jørgen; Jones, Graeme R.; Nash, David R.; Pedersen, Jes S.; Boomsma, Jacobus J.

    2008-01-01

    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects. PMID:19050762

  15. [Syagrus romanzoffiana (Arecaceae) seed utilization by ants in a secondary forest in South Brazil].

    Science.gov (United States)

    Silva, Fernanda R; Begnini, Romualdo M; Klier, Vinícius A; Scherer, Karla Z; Lopes, Benedito C; Castellani, Tânia T

    2009-01-01

    Ants can nest in a wide variety of substracts. This paper shows Syagrus romanzoffiana seed utilization by ants in an Atlantic secondary forest. We report 29 seeds occupied by small-bodied ants, with 27 of them showing at least two ant development stages. Although a large number of seeds were sampled, a low level of ant occupation was observed.

  16. Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem

    DEFF Research Database (Denmark)

    Stuble, Katharine L.; Kirkman, L. Katherine; Carroll, C. Ronald

    2011-01-01

    and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta......), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce......, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants...

  17. La escritura como espada ante el machismo

    OpenAIRE

    Rottoli, Sofía

    2016-01-01

    Cuando se trata de expresar una postura que abarque una temática demasiado amplia o controversial, recurrir a la escritura puede ser una buena opción de abordaje. Sobre todo cuando son discusiones que llevan años de vigencia. Las luchas feministas ante la violencia de género no son una excepción. Sus discusiones siempre tuvieron presencia en diversos campos, uno de ellos es la ya mencionada escritura. Centro de Investigación en Lectura y Escritura (CILE)

  18. Ecology: 'Devil's gardens' bedevilled by ants.

    Science.gov (United States)

    Frederickson, Megan E; Greene, Michael J; Gordon, Deborah M

    2005-09-22

    'Devil's gardens' are large stands of trees in the Amazonian rainforest that consist almost entirely of a single species, Duroia hirsuta, and, according to local legend, are cultivated by an evil forest spirit. Here we show that the ant Myrmelachista schumanni, which nests in D. hirsuta stems, creates devil's gardens by poisoning all plants except its host plants with formic acid. By killing these other plants, M. schumanni provides its colonies with abundant nest sites--a long-lasting benefit as colonies can live for 800 years.

  19. Ante-natal ionising radiation and cancer

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This editorial comments on the latest reports of the Oxford Survey of Childhood Cancer (now based on Birmingham). With 14759 pairs, the latest survey is over 10-fold larger than the 1958 report and the calculation of fatal childhood cancer rate at one case in 990 ante-natal radiographic examinations is rather larger than the early estimates, in spite of the fetal radiation dose having been halved and the cure rate for childhood leukemia being much improved. Comments are made on the comparisons with bomb survivors, and on the much increased fatal cancer incidence after first trimester radiography. (UK)

  20. Ant Systems for a Dynamic TSP - Ants Caught in a Traffic Jam

    NARCIS (Netherlands)

    Eyckelhof, C.J.; Dorigo, M.; Caro Di, G.; Snoek, M.; Sampels, M.

    2002-01-01

    In this paper we present a new Ants System approach to a dynamic Travelling Salesman Problem. Here the travel times between the cities are subject to change. To handle this dynamism several ways of adapting the pheromone matrix both locally and globally are considered. We show that the strategy of

  1. Nectar Theft and Floral Ant-Repellence: A Link between Nectar Volume and Ant-Repellent Traits?

    Science.gov (United States)

    Ballantyne, Gavin; Willmer, Pat

    2012-01-01

    As flower visitors, ants rarely benefit a plant. They are poor pollinators, and can also disrupt pollination by deterring other flower visitors, or by stealing nectar. Some plant species therefore possess floral ant-repelling traits. But why do particular species have such traits when others do not? In a dry forest in Costa Rica, of 49 plant species around a third were ant-repellent at very close proximity to a common generalist ant species, usually via repellent pollen. Repellence was positively correlated with the presence of large nectar volumes. Repellent traits affected ant species differently, some influencing the behaviour of just a few species and others producing more generalised ant-repellence. Our results suggest that ant-repellent floral traits may often not be pleiotropic, but instead could have been selected for as a defence against ant thieves in plant species that invest in large volumes of nectar. This conclusion highlights to the importance of research into the cost of nectar production in future studies into ant-flower interactions. PMID:22952793

  2. Partial incompatibility between ants and symbiotic fungi in two sympatric species of Acromyrmex leaf-cutting ants.

    Science.gov (United States)

    Bot, A N; Rehner, S A; Boomsma, J J

    2001-10-01

    We investigate the nature and duration of incompatibility between certain combinations of Acromyrmex leaf-cutting ants and symbiotic fungi, taken from sympatric colonies of the same or a related species. Ant-fungus incompatibility appeared to be largely independent of the ant species involved, but could be explained partly by genetic differences among the fungus cultivars. Following current theoretical considerations, we develop a hypothesis, originally proposed by S. A. Frank, that the observed incompatibilities are ultimately due to competitive interactions between genetically different fungal lineages, and we predict that the ants should have evolved mechanisms to prevent such competition between cultivars within a single garden. This requires that the ants are able to recognize unfamiliar fungi, and we show that this is indeed the case. Amplified fragment length polymorphism genotyping further shows that the two sympatric Acromyrmex species share each other's major lineages of cultivar, confirming that horizontal transfer does occasionally take place. We argue and provide some evidence that chemical substances produced by the fungus garden may mediate recognition of alien fungi by the ants. We show that incompatibility between ants and transplanted, genetically different cultivars is indeed due to active killing of the novel cultivar by the ants. This incompatibility disappears when ants are force-fed the novel cultivar for about a week, a result that is consistent with our hypothesis of recognition induced by the resident fungus and eventual replacement of incompatibility compounds during force-feeding.

  3. The importance of ants in cave ecology, with new records and behavioral observations of ants in Arizona caves

    Directory of Open Access Journals (Sweden)

    Robert B. Pape

    2016-09-01

    Full Text Available The importance of ants as elements in cave ecology has been mostly unrecognized. A global list of ant species recorded from caves, compiled from a review of existing literature, is presented. This paper also reviews what is currently known about ants occurring in Arizona (USA caves. The diversity and distribution represented in these records suggests ants are relatively common cave visitors (trogloxenes. A general utilization of caves by ants within both temperate and tropical latitudes may be inferred from this combined evidence. Observations of ant behavior in Arizona caves demonstrate a low level and sporadic, but persistent, use of these habitats and their contained resources by individual ant colonies. Documentation of Neivamyrmex sp. preying on cave-inhabiting arthropods is reported here for the first time. Observations of hypogeic army ants in caves suggests they may not penetrate to great vertical depth in search of prey, but can be persistent occupants in relatively shallow, horizontal sections of caves where they may prey on endemic cave animals. First cave records for ten ant species are reported from Arizona caves. These include two species of Neivamyrmex (N. nigrescens Cresson and Neivamyrmex sp.; Formicidae: Dorylinae, four myrmicines (Pheidole portalensis Wilson, Pheidole cf. porcula Wheeler, Solenopsis aurea Wheeler and Stenamma sp. Westwood, one dolichoderine (Forelius keiferi Wheeler and three formicines (Lasius arizonicus Wheeler, L. sitiens Wilson, and Camponotus sp. Mayr.

  4. ANT tuner retrofit for LEB cavity

    International Nuclear Information System (INIS)

    Walling, L.; Goren, Y.; Kwiatkowski, S.

    1994-03-01

    This report describes a ferrite tuner design for the LEB cavity that utilizes techniques for bonding ferrite to metallic cooling plates that is utilized in the high-power rf and microwave industry. A test tuner was designed to fit into the existing LEB-built magnet and onto the Grimm LEB Cavity. It will require a new vacuum window in order to attain maximal tuning range and high voltage capability and a new center conductor of longer length and a different vacuum window connection than the Grimm center conductor. However, the new center conductor will be essentially identical to the Grimm center conductor in its basic construction and in the way it connects to the stand for support. The tuner is mechanically very similar to high-power stacked circulators built by ANT of Germany and was designed according to ANT's established engineering and design criteria and SSC LEB tuning and power requirements. The tuner design incorporates thin tiles of ferrite glued using a high-radiation-resistance epoxy to copper-plated stainless steel cooling plates of thickness 6.5 mm with water cooling channels inside the plates. The cooling plates constitute 16 pie-shaped segments arranged in a disk. They are electrically isolated from each other to suppress eddy currents. Five of these disks are arranged in parallel with high-pressure rf contacts between the plates at the outer radius. The end walls are slotted copper-plated stainless steel of thickness 3 mm

  5. Loading pattern optimization using ant colony algorithm

    International Nuclear Information System (INIS)

    Hoareau, Fabrice

    2008-01-01

    Electricite de France (EDF) operates 58 nuclear power plants (NPP), of the Pressurized Water Reactor type. The loading pattern optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R and D has developed automatic optimization tools that assist the experts. LOOP is an industrial tool, developed by EDF R and D and based on a simulated annealing algorithm. In order to improve the results of such automatic tools, new optimization methods have to be tested. Ant Colony Optimization (ACO) algorithms are recent methods that have given very good results on combinatorial optimization problems. In order to evaluate the performance of such methods on loading pattern optimization, direct comparisons between LOOP and a mock-up based on the Max-Min Ant System algorithm (a particular variant of ACO algorithms) were made on realistic test-cases. It is shown that the results obtained by the ACO mock-up are very similar to those of LOOP. Future research will consist in improving these encouraging results by using parallelization and by hybridizing the ACO algorithm with local search procedures. (author)

  6. Ant Foraging Behavior for Job Shop Problem

    Directory of Open Access Journals (Sweden)

    Mahad Diyana Abdul

    2016-01-01

    Full Text Available Ant Colony Optimization (ACO is a new algorithm approach, inspired by the foraging behavior of real ants. It has frequently been applied to many optimization problems and one such problem is in solving the job shop problem (JSP. The JSP is a finite set of jobs processed on a finite set of machine where once a job initiates processing on a given machine, it must complete processing and uninterrupted. In solving the Job Shop Scheduling problem, the process is measure by the amount of time required in completing a job known as a makespan and minimizing the makespan is the main objective of this study. In this paper, we developed an ACO algorithm to minimize the makespan. A real set of problems from a metal company in Johor bahru, producing 20 parts with jobs involving the process of clinching, tapping and power press respectively. The result from this study shows that the proposed ACO heuristics managed to produce a god result in a short time.

  7. The effect of diet and opponent size on aggressive interactions involving caribbean crazy ants (Nylanderia fulva.

    Directory of Open Access Journals (Sweden)

    Katherine C Horn

    Full Text Available Biotic interactions are often important in the establishment and spread of invasive species. In particular, competition between introduced and native species can strongly influence the distribution and spread of exotic species and in some cases competition among introduced species can be important. The Caribbean crazy ant, Nylanderia fulva, was recently introduced to the Gulf Coast of Texas, and appears to be spreading inland. It has been hypothesized that competition with the red imported fire ant, Solenopsis invicta, may be an important factor in the spread of crazy ants. We investigated the potential of interspecific competition among these two introduced ants by measuring interspecific aggression between Caribbean crazy ant workers and workers of Solenopsis invicta. Specifically, we examined the effect of body size and diet on individual-level aggressive interactions among crazy ant workers and fire ants. We found that differences in diet did not alter interactions between crazy ant workers from different nests, but carbohydrate level did play an important role in antagonistic interactions with fire ants: crazy ants on low sugar diets were more aggressive and less likely to be killed in aggressive encounters with fire ants. We found that large fire ants engaged in fewer fights with crazy ants than small fire ants, but fire ant size affected neither fire ant nor crazy ant mortality. Overall, crazy ants experienced higher mortality than fire ants after aggressive encounters. Our findings suggest that fire ant workers might outcompete crazy ant workers on an individual level, providing some biotic resistance to crazy ant range expansion. However, this resistance may be overcome by crazy ants that have a restricted sugar intake, which may occur when crazy ants are excluded from resources by fire ants.

  8. Aphid egg protection by ants: a novel aspect of the mutualism between the tree-feeding aphid Stomaphis hirukawai and its attendant ant Lasius productus

    Science.gov (United States)

    Matsuura, Kenji; Yashiro, Toshihisa

    2006-10-01

    Aphids often form mutualistic associations with ants, in which the aphids provide the ants with honeydew and the ants defend the aphids from predators. In this paper, we report aphid egg protection by ants as a novel aspect of the deeply interdependent relationship between a tree-feeding aphid and its attendant ant. The ant Lasius productus harbours oviparous females, males, and eggs of the hinoki cypress-feeding aphid Stomaphis hirukawai in its nests in winter. We investigated the behaviour of ants kept with aphid eggs in petri dishes to examine whether the ants recognise the aphid eggs and tend them or only provide a refuge for the aphids. Workers carried almost all of the aphid eggs into the nest within 24 h. The ants indiscriminately tended aphid eggs collected from their own colonies and those from other ant colonies. The ants cleaned the eggs and piled them up in the nest, and egg tending by ants dramatically increased aphid egg survival rates. Starving the ants showed no significant effect on aphid egg survivorship. Without ants, aphid eggs were rapidly killed by fungi. These results suggested that grooming by the ants protected the aphid eggs, at least, against pathogenic fungi. This hygienic service afforded by the ants seems indispensable for egg survival of these aphids in an environment rich in potentially pathogenic microorganisms.

  9. Current and potential ant impacts in the Pacific region

    Science.gov (United States)

    Loope, Lloyd L.; Krushelnycky, Paul D.

    2007-01-01

    Worldwide, ants are a powerful ecological force, and they appear to be dominant components of animal communities of many tropical and temperate ecosystems in terms of biomass and numbers of individuals (Bluthgen et al. 2000). For example, ants comprise up to 94% of arthropod individuals in fogging samples taken from diverse lowland tropical rainforest canopies, and 86% of the biomass (Davidson et al. 2003). The majority of these ant species and individuals obtain carbohydrates either from extrafloral nectaries or from sap-feeding Hemiptera that pass carbohydrate-rich “honeydew” to attending ants while concentrating nitrogen (N) from N-poor plant sap (Davidson et al. 2003). Honeydew and nectar represent key resources for arboreal ant species, although most ant species are at least partly carnivorous or scavengers (Bluthgen et al. 2004). In contrast to most of the terrestrial world, the biotas of many Pacific islands evolved without ants. Whereas endemic ant species are found in New Zealand (ca. 10 spp.), Tonga (ca. 10 spp.), and Samoa (ca. 12 spp.), other islands of Polynesia and parts of Micronesia likely lack native ants (Wilson and Taylor 1967, Wetterer 2002, Wetterer and Vargo 2003). About 20 Indo-Australian and western Pacific ant species range to the east and north of Samoa, but it is unclear how many of these were transported there by humans at some time (Wilson and Taylor 1967). Most of the remainder of the ant species currently found on Pacific islands are widespread species that fall in the category of “tramp species,” dispersed by recent human commerce and generally closely tied to human activity and urban areas (Wilson and Taylor 1967, McGlynn 1999). In Pacific island situations, some of these tramp ant species are able to thrive beyond areas of human activity. Relatively few ant species have been successful invaders of native communities on continents, and these include most of the species that pose the greatest problems for Pacific islands

  10. Ultrastructure of antennal sensillae of the samsum ant ...

    African Journals Online (AJOL)

    Black ant (Samsum), Pachycodyla sennarrensis, stings and injects venom and inflicts allergy (a rare clinical problem) due to its local and systemic reaction, which is considered as a health hazard amongst Saudi society. Thus, black ant is a source of serious concern for the government and experts as well.

  11. Development of a Bait System for the Pharaoh's Ant, Monomorium ...

    African Journals Online (AJOL)

    The infestation of the Pharaoh's ant, Monomorium pharaonis L. is widespread and, sometimes, very serious in homes, hospitals, restaurants, factories, etc. People are helpless because effective baited traps are not available locally, and little has been done locally to develop effective control strategies for these ants.

  12. A preliminary checklist of the ants (Hymenoptera: Formicidae) of ...

    African Journals Online (AJOL)

    A preliminary species checklist of the ants (Hymenoptera: Formicidae) of. Kakamega Forest, Western Kenya, is presented. The species list is based on specimens sampled from 1999 until 2009, which are deposited in the ant collection of the Zoological Research Museum Koenig, Bonn, Germany, and the Natural History ...

  13. Ant species richness of fynbos and forest ecosystems in the ...

    African Journals Online (AJOL)

    The ant fauna in fynbos and forest habitats in the southern Cape are compared. There is no significant difference in ant species richness between the two undisturbed habitat types, and the only two species common to both are Acantholepis capensis and Camponotus maculatus. The degree of Hakea sericea infestation in ...

  14. Volatile chemicals in glands of the carpenter ant, Camponotus ...

    African Journals Online (AJOL)

    Volatile chemicals in glands of the carpenter ant, Camponotus arminius. J.M. Brand, L.V. Mabinya, E.D. Morgan. Abstract. Camponotus arminius is a large black carpenter ant that occurs in tropical and sub-tropical Africa and has extensive foraging trails both in trees and on the ground. Analysis of excised mandibular glands ...

  15. Novel Phialophora species from leaf-cutting ants (tribe Attini)

    NARCIS (Netherlands)

    Attili-Angelis, D.; Duarte, A.P.M.; Pagnocca, F.C.; Nagamoto, N.S.; de Vries, M.; Stielow, J.B.; de Hoog, G.S.

    2014-01-01

    Ants in the tribe Attini (Hymenoptera, Formicidae) maintain a 50 million-year-old lifestyle of co-evolution with symbiotic basidiomycetous fungi which they cultivate as essential source of nutrition. However, other microorganisms have been reported from ant habitats indicating a higher diversity of

  16. Why do house-hunting ants recruit in both directions?

    NARCIS (Netherlands)

    Planqué, R.; Dechaume-Moncharmont, F.-X.; Franks, N.R.; Kovacs, T.; Marshall, J.A.R.

    2007-01-01

    To perform tasks, organisms often use multiple procedures. Explaining the breadth of such behavioural repertoires is not always straightforward. During house hunting, colonies of Temnothorax albipennis ants use a range of behaviours to organise their emigrations. In particular, the ants use tandem

  17. Tracing the rise of ants - out of the ground.

    Directory of Open Access Journals (Sweden)

    Andrea Lucky

    Full Text Available The evolution of ants (Hymenoptera: Formicidae is increasingly well-understood due to recent phylogenetic analyses, along with estimates of divergence times and diversification rates. Yet, leading hypotheses regarding the ancestral habitat of ants conflict with new findings that early ant lineages are cryptic and subterranean. Where the ants evolved, in respect to habitat, and how habitat shifts took place over time have not been formally tested. Here, we reconstruct the habitat transitions of crown-group ants through time, focusing on where they nest and forage (in the canopy, litter, or soil. Based on ancestral character reconstructions, we show that in contrast to the current consensus based on verbal arguments that ants evolved in tropical leaf litter, the soil is supported as the ancestral stratum of all ants. We also find subsequent movements up into the litter and, in some cases, into the canopy. Given the global importance of ants, because of their diversity, ecological influence and status as the most successful eusocial lineage on Earth, understanding the early evolution of this lineage provides insight into the factors that made this group so successful today.

  18. In vitro studies of ante-mortem proliferation kinetics

    International Nuclear Information System (INIS)

    McBride, W.H.; Withers, H.R.

    1986-01-01

    Using K562 human erythroblastoid cells, it was concluded that dose fractionation has no discrepant effect on the ante-mortem proliferation kinetics of doomed cells as opposed to clonogenic cell survival and that effects on ante-mortem proliferation kinetics cannot be solely responsible for the differences in fractionation response between early and late responding tissues. (UK)

  19. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

  20. Life-Histories of Sub-Arctic Ants

    OpenAIRE

    Heinze, Jürgen

    1993-01-01

    Ant species belonging to seven genera occur in habitats near the tree line in the Northern Hemisphere. An analysis of colony founding strategies suggests that in addition to physiological cold resistance, behavioral and sociometric adaptations might be important for survival and propagation of ants in subarctic biomes.

  1. Studies of laboulbeniales (Fungi, Ascomycota) on myrmica ants (II)

    NARCIS (Netherlands)

    Haelewaters, Danny; Boer, Peter; Gort, Gerrit; Noordijk, Jinze

    2015-01-01

    One group of important insect parasites are the Laboulbeniales (Ascomycota), microscopic fungi that live attached to the exterior of their hosts, mainly beetles, but also mites, millipedes, earwigs, and ants. Rickia wasmannii is a common fungus in Europe and is limited to the ant genus Myrmica

  2. ADAPTIVE ANT COLONY OPTIMIZATION BASED GRADIENT FOR EDGE DETECTION

    Directory of Open Access Journals (Sweden)

    Febri Liantoni

    2014-08-01

    Full Text Available Ant Colony Optimization (ACO is a nature-inspired optimization algorithm which is motivated by ants foraging behavior. Due to its favorable advantages, ACO has been widely used to solve several NP-hard problems, including edge detection. Since ACO initially distributes ants at random, it may cause imbalance ant distribution which later affects path discovery process. In this paper an adaptive ACO is proposed to optimize edge detection by adaptively distributing ant according to gradient analysis. Ants are adaptively distributed according to gradient ratio of each image regions. Region which has bigger gradient ratio, will have bigger number of ant distribution. Experiments are conducted using images from various datasets. Precision and recall are used to quantitatively evaluate performance of the proposed algorithm. Precision and recall of adaptive ACO reaches 76.98 % and 96.8 %. Whereas highest precision and recall for standard ACO are 69.74 % and 74.85 %. Experimental results show that the adaptive ACO outperforms standard ACO which randomly distributes ants.

  3. Patterns of male parentage in the fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Boomsma, JJ

    2003-01-01

    Ant queens from eight species, covering three genera of lower and two genera of higher attine ants, have exclusively or predominantly single mating. The ensuing full-sib colonies thus have a strong potential reproductive conflict between the queen and the workers over male production...

  4. Odorous house ants (Tapinoma sessile as back-seat drivers of localized ant decline in urban habitats.

    Directory of Open Access Journals (Sweden)

    Adam Salyer

    Full Text Available Invasive species and habitat disturbance threaten biodiversity worldwide by modifying ecosystem performance and displacing native organisms. Similar homogenization impacts manifest locally when urbanization forces native species to relocate or reinvade perpetually altered habitat. This study investigated correlations between ant richness and abundance in response to urbanization and the nearby presence of invasive ant species, odorous house ants (Tapinoma sessile, within its native region. Surveying localized ant composition within natural, semi-natural, and urban habitat supported efforts to determine whether T. sessile appear to be primary (drivers threats as instigators or secondary (passengers threats as inheritors of indigenous ant decline. Sampling 180 sites, evenly split between all habitats with and without T. sessile present, yielded 45 total species. Although urbanization and T. sessile presence factors were significantly linked to ant decline, their interaction correlated to the greatest reduction of total ant richness (74% and abundance (81%. Total richness appeared to decrease from 27 species to 18 when natural habitat is urbanized and from 18 species to 7 with T. sessile present in urban plots. Odorous house ant presence minimally influenced ant communities within natural and semi-natural habitat, highlighting the importance of habitat alteration and T. sessile presence interactions. Results suggest urbanization releases T. sessile from unknown constraints by decreasing ant richness and competition. Within urban environment, T. sessile are pre-adapted to quickly exploit new resources and grow to supercolony strength wherein T. sessile drive adjacent biodiversity loss. Odorous house ants act as passengers and drivers of ecological change throughout different phases of urban 'invasion'. This progression through surviving habitat alteration, exploiting new resources, thriving, and further reducing interspecific competition supports a

  5. Programa para el desarrollo moral y el fomento de valores en jóvenes adultos con discapacidad intelectual a través de juegos predeportivos y dilemas morales. Programa DEMVA.

    OpenAIRE

    Sánchez Romero, Elisa Isabel

    2017-01-01

    La presente tesis doctoral evalúa la eficacia del programa para el desarrollo moral y el fomento de valores en jóvenes adultos con discapacidad intelectual a través de juegos predeportivos y dilemas morales (programa DEMVA). Situado en el contexto de la educación superior, concretamente en la Universidad Católica de Murcia (UCAM), el programa DEMVA se llevó a cabo en la asignatura “Valores, tiempo libre y deporte”, del primer curso del programa UCAMPACITAS dirigido a la inserción socio-labora...

  6. Promoção de atitudes ambientais favoráveis através de debates de dilemas ecológicos Promoting favorable attitudes toward the environment through debates of dilemmas with ecological content

    Directory of Open Access Journals (Sweden)

    Ângela Maria Brasil Biaggio

    1999-12-01

    Full Text Available Este estudo se propôs a promover atitudes ambientais favoráveis em adolescentes através de debates de dilemas com conteúdo ecológico. Os dilemas foram elaborados com base na teoria de julgamento moral de Kohlberg e na técnica de discussão de dilemas morais em grupo, criada por Blatt e Kohlberg. Dezesseis estudantes do primeiro ano do segundo grau de uma escola pública de Porto Alegre participaram do estudo, tendo sido aplicado nesses estudantes, como pré-teste e pós-teste, um questionário de dez itens sobre atitudes em relação à ecologia. As respostas dos participantes foram avaliadas numa escala de zero a dois pontos, indicando o grau de maturidade de atitudes em relação ao ambiente. O grau de participação nas discussões de dilemas também foi analisado. A análise dos dados indica que a técnica foi eficaz somente para os alunos considerados participativos nas discussões.This research study had the purpose of promoting favorable attitudes toward the environment in adolescents through debates of dilemmas with ecological content. The dilemmas were elaborated with basis on Kohlberg's theory of moral judgment and on Blatt and Kohlberg's group discussion technique. Sixteen students from the first year of high-school from a public school in Porto Alegre (Brazil, participated in the research study. These students were administred a ten-item questionnaire about attitudes regarding ecology, as pre-test and post-test. The participants responses were rated in a zero to two points scale, indicating the degree of maturity of attitudes regarding the environment. The degree of participation in the discussions was also analyzed. The analysis of data reveals that the technique worked only for those students considered high in participation in the discussions.

  7. Weaver Ants to Control Fruit Fly Damage to Tanzanian Mangoes

    DEFF Research Database (Denmark)

    Kirkegaard, Nina

    in Australia and West Africa. In this study, small scale farmers did not think weaver ants protected their mangoes from fruit flies. Observational studies confirmed the farmers’ views. No volatile compounds, likely to be responsible for the weaver ants’ deterrent effect, were identified. This study focused...... mangoes varied a lot with zero infestation in some fruits and more than 100 pupae emerging from other fruits, indicating that other factors than the presence of weaver ants affect the fruit flies’ decision on where to oviposit. It was not uncommon for farmers to place newly harvested mangoes below mango...... not shown to be effectively deterring fruit flies, there is no great motivation for farmers to adopt weaver ants. Assuming the weaver ants could be managed in a way that made weaver ants deter fruit flies effectively there are still some economic aspects which should be studied further. It is necessary...

  8. Behind every great ant, there is a great gut

    DEFF Research Database (Denmark)

    Poulsen, Michael; Sapountzis, Panagiotis

    2012-01-01

    on the potential contribution of the ants’ gut symbionts. This issue of Molecular Ecology contains a study by Anderson et al. (2012), who take a comparative approach to explore the link between trophic levels and ant microbiomes, specifically, to address three main questions: (i) Do closely related herbivorous...... conserved gut microbiomes, suggesting symbiont functions that directly relate to dietary preference of the ant host. These findings suggest an ecological role of gut symbionts in ants, for example, in metabolism and/or protection, and the comparative approach taken supports a model of co-evolution between...... ant species and specific core symbiont microbiomes. This study, thereby, highlights the omnipresence and importance of gut symbioses—also in the Hymenoptera—and suggests that these hitherto overlooked microbes likely have contributed to the ecological success of the ants....

  9. Endophytic fungi reduce leaf-cutting ant damage to seedlings

    Science.gov (United States)

    Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

    2011-01-01

    Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

  10. Egg-laying butterflies distinguish predaceous ants by sight.

    Science.gov (United States)

    Sendoya, Sebastián F; Freitas, André V L; Oliveira, Paulo S

    2009-07-01

    Information about predation risks is critical for herbivorous insects, and natural selection favors their ability to detect predators before oviposition and to select enemy-free foliage when offspring mortality risk is high. Food plants are selected by ovipositing butterflies, and offspring survival frequently varies among plants because of variation in the presence of predators. Eunica bechina butterflies oviposit on Caryocar brasiliense, an ant-defended plant. Experiments with dried Camponotus and Cephalotes ants pinned to leaves revealed that butterflies use ant size and form as visual cues to avoid ovipositing on plant parts occupied by ants more likely to kill larval offspring. Presence of sap-sucking bugs did not affect butterfly oviposition. This is the first demonstration that visual recognition of predators can mediate egg-laying decisions by an insect herbivore and that an insect will discriminate among different species of potential predators. This unusual behavioral capability permits specialization on a risky, ant-defended food plant.

  11. ANT International chemistry update and best practices

    International Nuclear Information System (INIS)

    Nordmann, F.; Odar, S.; Venz, H.; Kysela, J.; Ruehle, W.; Riess, R.

    2010-01-01

    There is an increasing number of Nuclear Power Plants (NPP) in various countries. Their chemistry practices are different due to the variety of designs and experiences while in the past the view was more monolithic. This is allowing a very rich experience that is extremely difficult to fully be aware of. ANT International is now collecting and evaluating these data as well as related R and D Information. This allows interested parties to have an easier access to the various sources of information. The chemistry experts associated to ANT International have been gathering a comprehensive detailed view of: The numerous laboratory data gained all over the world during the past decades; The extensive plant operating experiences with various types of chemistry strategies, crosschecked for various types of reactors designs and materials; An experienced international knowledge able to give the comprehensive overview that young engineers now in charge of many other activities are unable to fully cover. This paper gives the core conclusions of the detailed ANT International reports and results that have recently been gathered in the area of chemistry. It particularly covers: The primary water chemistry and its relation with radionuclides, dose rates and fuel behaviour; The secondary water chemistry focusing on its rationale selection depending on materials, design and other constraints; The start up and shutdown chemistry with it large variety of practices hardly understandable even for some experts; and, The maintenance remedies such as decontamination, steam generator cleaning and its alternate options. Various types of Reactor designs (PWR, VVER, BWR, CANDU®) are considered. The different materials, for example the impact of steam generator tubing and its evolution on the secondary water chemistry rationale or on the radioactivity built-up in the primary coolant, are described. The ways to improve the plant operation with a long term reliability as well as the most

  12. The regulation of ant colony foraging activity without spatial information.

    Directory of Open Access Journals (Sweden)

    Balaji Prabhakar

    Full Text Available Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.

  13. A distanásia como geradora de dilemas éticos nas Unidades de Terapia Intensiva: considerações sobre a participação dos enfermeiros La distanasia como generadora de dilemas éticos en las Unidades deTerapia Intensiva: algunos aspectos a cerca de lo envolvimiento de los enfermeros Disthanasia as an ethical dilemma at the Intensive Care Units: considerations about nurses involvement

    Directory of Open Access Journals (Sweden)

    Maria Cecilia Toffoletto

    2005-09-01

    Full Text Available A distanásia apresenta-se como uma das fontes geradoras de dilemas éticos nas Unidades de Terapia Intensiva (UTI. Discute-se o contexto que favorece a prática da distanásia nesse ambiente, com ênfase na utilização excessiva do suporte tecnológico. Tecemos comentários sobre a participação dos familiares e profissionais envolvidos, principalmente médicos e enfermeiros, considerando-se o papel sócio-profissional atribuído a cada um. Pretende-se com as considerações apresentadas, fornecer subsídios para a reflexão do tema, com vistas a uma participação mais ativa dos enfermeiros de UTI nos dilemas éticos relacionados à distanásia.La distanasia se presenta como una de las fuentes generadoras de los dilemas éticos en las Unidades de Terapia Intensiva (UTI Discute el contexto que favorece la práctica de la distanasia en este ambiente, con énfasis en la utilización excesiva del arsenal tecnologico. Además de los comentarios sobre la posición de los familiares y de los profesionales involucrados, principalmente los médicos y enfermeros, se consideró el papel socio-profesional que se atribuye a cada uno. Para finalizar, los profesionales del area son estimulados a refletir sobre el tema y los enfermeros a participar de manera más activa en las discusiones de los dilemas éticos relacionados a la distanasia.Disthanasia is conceptualized and presented as an ethical dilemma in Intensive Care Units (ICU. The context favoring the disthanasia practice on this environment focusing the excessive use of technological devices will be discussed. The study will approach the family, physician and nurse’s participation in the situations, considering the social and professional role of each one. This study aims to provide support for healthcare professionals to reflect on this subject, aiming the nurse’s more effective participation on ethical dilemmas related to disthanasia.

  14. Entregas, adopciones y dilemas en el campo de organismos destinados a la infancia Surrenders, adoptions, and dilemmas in the field of organisms intended for childhood

    Directory of Open Access Journals (Sweden)

    Carla Villalta

    2011-04-01

    Full Text Available En este artículo se analizan los debates y dilemas que plantean las denominadas "entregas directas" en el campo de instituciones y agentes responsables de conceder las adopciones de niños. Este término designa la entrega que las madres u otros miembros de la familia biológica realizan de sus niños a otras personas para que los adopten. Para dar cuenta de los significados actualmente asociados a estas prácticas, por un lado, se describe y analiza el proceso a través del cual el procedimiento de la entrega de niños por escritura pública fue suprimido de la legislación argentina y, por otro lado, se focaliza el análisis en casos de adopciones legales de niños que fueron entregados en forma directa por sus madres y/o familias de origen. A través de este análisis, se examinan las formas que la intervención estatal asume cuando tiene por objetivos proteger a una población considerada 'vulnerable' y combatir el 'tráfico de niños'. Esta indagación conduce a explorar el dilema que representa la adopción de niños en una sociedad atravesada por profundas desigualdades sociales, y a reflexionar sobre cuáles son los derechos que les son reconocidos a aquellas mujeres para quienes la entrega de un hijo en adopción constituye una opción dentro de un limitado abanico de opciones.In this article we analyze the different debates and dilemmas outlined by the so-called "direct surrenders" in the field of institutions and agents responsible for granting the adoption of children. This term designates the surrender that mothers or other members of the biological family make of their children to other people for their adoption. To account for the meanings currently associated to these practices, on one hand, we describe and analyze the process through which the surrender of children performed by public deed was suppressed by Argentine legislation. On the other hand, we focus on the analysis of legal adoption cases of children who were directly

  15. Immune defense in leaf-cutting ants

    DEFF Research Database (Denmark)

    Armitage, Sophie A O; Broch, Jens F; Marín, Hermogenes Fernández

    2011-01-01

    To ameliorate the impact of disease, social insects combine individual innate immune defenses with collective social defenses. This implies that there are different levels of selection acting on investment in immunity, each with their own trade-offs. We present the results of a cross......-fostering experiment designed to address the influences of genotype and social rearing environment upon individual and social immune defenses. We used a multiply mating leaf-cutting ant, enabling us to test for patriline effects within a colony, as well as cross-colony matriline effects. The worker's father influenced...... both individual innate immunity (constitutive antibacterial activity) and the size of the metapleural gland, which secretes antimicrobial compounds and functions in individual and social defense, indicating multiple mating could have important consequences for both defense types. However, the primarily...

  16. Ex-ante Evaluation von Investitionsalternativen

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    Matthias Müller

    2017-12-01

    Full Text Available Der Beitrag zeigt, wie mit Hilfe der Methode der agentenbasierten Modellierung und Simulation (ABMS ein Beitrag zur ex-ante Policy-Beratung geleistet werden kann. Anhand eines exemplarischen Anwendungsfalls, der VISIBLE Simulationsumgebung („Virtual Simulation Lab for the Analysis of Investments in Learning and Education“, diskutieren wir die Konsequenzen unterschiedlicher Kooperationsförderinstrumente für Wissensdiffusionsprozesse in Netzwerken am Beispiel der Region Heilbronn-Franken. Die Simulationsergebnisse zeigen, dass die strukturelle Konfiguration eines regionalen Innovationssystems eine zentrale Bedeutung für die Gestaltung von Kooperationsfördermaßnahmen hat und dass Interventionen, die darauf abzielen, Wissenstransfer zwischen den Akteuren anzuregen, genau die entgegengesetzten Wirkungen entfalten können.

  17. Swarm controlled emergence for ant clustering

    DEFF Research Database (Denmark)

    Scheidler, Alexander; Merkle, Daniel; Middendorf, Martin

    2013-01-01

    .g. moving robots, and clustering algorithms. Design/methodology/approach: Different types of control agents for that ant clustering model are designed by introducing slight changes to the behavioural rules of the normal agents. The clustering behaviour of the resulting swarms is investigated by extensive...... for future research to investigate the application of the method in other swarm systems. Swarm controlled emergence might be applied to control emergent effects in computing systems that consist of many autonomous components which make decentralized decisions based on local information. Practical...... simulation studies. Findings: It is shown that complex behavior can emerge in systems with two types of agents (normal agents and control agents). For a particular behavior of the control agents, an interesting swarm size dependent effect was found. The behaviour prevents clustering when the number...

  18. Discrimination Behavior in the Supercolonial Pharaoh Ant

    DEFF Research Database (Denmark)

    Pontieri, Luigi

    The majority of eusocial insect species live in small, kin structured colonies that are mutually aggressive and rarely interact. By contrast, a restricted group of ant species show a peculiar social organization called unicoloniality, where colonies can grow to vast networks of geographically...... and genetic distance between colony pairs, further confirming the important role of endogenous cues in the nestmate recognition of this species. The third chapter presents a methodological study on the best procedures for identifying chemical compounds used for nestmate recognition in social insects. We first...... evaluated the power of different combinations of data transformation and chemical distance calculation in differentiating between true nestmate recognition (NMR) cues and other compounds. We found that particular combinations of statistical procedures are more effective in differentiating NMR cues from...

  19. Ethical Dilemmas when Diagnosing Hypertension Dilemas éticos en el diagnóstico de hipertensión arterial

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    Rolando Montero Díaz

    2012-12-01

    Full Text Available A review on the ethical dilemmas in the diagnosis of hypertension and some elements in the emergence of the bioethics concept was performed. Ethical conflicts that appear at each stage of diagnosis of hypertension: at the time of providing the information, at the point of indication and performance of diagnostic tests, when communicating the diagnosis and during subsequent decision making were identified. We conclude that technological development will introduce new ethical decisions in the diagnosis of hypertension that will increasingly involve the interests of society and create, in one way or another, ethical and moral conflict in the decision making process.Se realizó una revisión sobre los dilemas éticos en el diagnóstico de la hipertensión arterial, así como de algunos elementos en el surgimiento del concepto de bioética. Se identificaron los conflictos éticos que aparecen en cada etapa del diagnóstico de la hipertensión arterial: en el momento de suministrar la información, en el instante de la indicación y realización de las pruebas diagnósticas, en la comunicación del diagnóstico y en la toma de decisiones posteriores. Se concluye que el desarrollo tecnológico va a introducir nuevas decisiones éticas en el diagnóstico de la hipertensión arterial que van a involucrar cada vez más los intereses de la sociedad y crear de una manera u otra conflictos éticos y morales en la toma de decisiones.

  20. Dilemas da política de distribuição de medicamentos antirretrovirais no Brasil Policy dilemmas in providing antiretroviral treatment in Brazil

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    Regina Ferro do Lago

    2010-11-01

    Full Text Available Este artigo trata dos constrangimentos institucionais que têm afetado a política brasileira de provisão de medicamentos contra a Aids. É analisado o conflito normativo observado na política de Aids entre as regras internacionais da propriedade intelectual, em especial a proteção de patentes, e a orientação de acesso universal e gratuito a medicamentos, que norteia a política brasileira. Esses constrangimentos não têm tido sucesso em alterar a configuração distributiva da política pública brasileira; contudo, vêm alterando as condições de sustentabilidade da política pública. Considerando que a principal barreira para a produção de medicamentos protegidos por patente é institucional e não tecnológica, o governo brasileiro tem enfrentado o dilema da tomada de decisão entre a manutenção da regra de monopólio ou o incentivo à competitividade que permita o posicionamento eficiente dos produtores nacionais e dos países emergentes.This paper addresses institutional constraints that have affected Brazilian politics regarding provision of anti-retroviral treatment (ART to HIV/Aids patients. We analyzed the normative conflict resulting from international agreements on intellectual property rights, especially patent protection, and the constitutional rights of Brazilian patients to universal and free access to ART. These constraints have not substantially changed the Brazilian public policy yet, but they may impact the future sustainability of this policy. As the main barrier to the production of patented drugs is not technological but institutional, Brazilian government faces a dilemma. It may either abide by existing monopolistic restrictions or it may incite competitiveness of domestic industries and developing countries in the pharmaceutical market.

  1. A la búsqueda de la confiscada facultad de juzgar: Una propuesta iusconstructivista al dilema del juzgamientos de los crímenes de Estado

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    Daniel Feierstein

    2015-10-01

    Full Text Available En este artículo, se busca reflexionar sobre los componentes fundamentales de la facultad humana de juzgar y su vinculación con la tarea del juicio realizada por los jueces en el contexto del marco jurídico. Se intentará poner en cuestión la estricta delimitación que propone el positivismo[1] entre la capacidad humana de juzgar (que proviene del criterio moral y la acción jurídica, ya que dicha delimitación pareciera postular la posibilidad de prescindir del ejercicio de la facultad de juzgar a la hora de aplicar el derecho positivo. Actualizando el dilema ius-naturalismo/ius-positivismo para pensar críticamente el juzgamiento de crímenes de Estado, se aventurará una tercera salida, bautizada como ius-constructivismo y basada en los desarrollos de la psicología y la epistemología genéticas. [1] .- Carlos Nino distingue en las escuelas jurídicas como "positivismo conceptual" (donde ubica a autores Bentham, Austin, Kelsen, Ross o Hart, entre otros a la postulación de que los sistemas normativos no requieren derivar de principios morales previos para ser considerados válidos, sino que su propia existencia y producción normativa los valida como tales. Nino también distingue lo que llama un "positivismo ideológico", que incluso cuestiona la existencia de principios morales. Aquí, sin embargo, se entenderá como positivismo jurídico al positivismo conceptual y será con dichas posiciones que se darán los debates fundamentales. Véase, entre otras obras, Nino (1984, 1985.

  2. Fronteras naturales versus fronteras político- administrativas: desafíos y dilemas que enfrentan los parques naturales regionales en el gobierno multi-escalar

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    Constanza Parra

    2008-01-01

    Full Text Available Este artículo analiza los desafíos en la gobernanza de zonas naturales protegidas, subrayando tensiones y dilemas que se derivan de la existencia simultánea de fronteras naturales y fronteras político-administrativas que raramente coinciden. Al partir del supuesto según el cual la articulación entre escalas territoriales es un factor determinante en la sustentabilidad de todo tipo de territorios, la reflexión se focaliza en los desafíos que enfrentan los Parques Regionales de Francia en un contexto de gobierno multi-escalar. Más específicamente, se analizan las contradicciones que se observan entre una multiplicación de fronteras político-administrativas subnacionales y los imperativos de sostenibilidad a los que se encuentran subordinados estos territorios. A partir del examen del Parque Regional Morvan, se concluye que la superabundancia de instituciones subnacionales, cuya instauración tiene por objetivo avanzar en los principios democráticos y de participación ciudadana de un desarrollo sustentable, genera dinámicas de rivalidad y competencia entre territorios que atentan contra su sostenibilidad. El estudio de campo fue realizado mediante una metodología cualitativa y se utilizó la entrevista en profundidad con actores claves como base para la recolección de información, así como la realización de observaciones, visitas de terreno y análisis de fuentes secundarias.

  3. DIMENSIONALIDAD DE LA RESPONSABILIDAD SOCIAL EMPRESARIAL PERCIBIDA Y SUS EFECTOS SOBRE LA IMAGEN Y LA REPUTACIÓN: UNA APROXIMACIÓN DESDE EL MODELO DE CARROLL

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    ALEJANDRO ALVARADO HERRERA

    2008-01-01

    Full Text Available La literatura de marketing sugiere que las acciones y programas de responsabilidad social empresarial podrían mejorar la imagen y la reputación de las empresas ante los ojos de sus consumidores y ser una importante fuente de ventaja competitiva para las mismas. Sin embargo, poco se sabe acerca las percepciones de estos stakeholders al respecto y sobre sus efectos en dichas variables. Para conocerlos, se llevó a cabo una revisión de la literatura, en donde se planteo un modelo teórico de relaciones estructurales el cual es contrastado empíricamente a través del análisis de su estructura de covarianzas. Para tal objetivo, se utiliza una muestra de 358 consumidores jóvenes de telefonía celular de la ciudad de Valencia, España. Los resultados indican que cada una de las dimensiones estudiadas de la responsabilidad social influyen significativa y directamente sobre la imagen de la marca, e indirectamente sobre la reputación. Tras la discusión, se plantean las conclusiones, las implicaciones académicas y profesionales, las limitaciones de la investigación y se proponen nuevas líneas de investigación futuras.

  4. La información obtenida por tecnologías espaciales ante el derecho internacional

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    Silvia Maureen Williams

    2008-05-01

    Full Text Available ResumenEl trabajo avanza sobre investigaciones recientes dirigidas por la autora en el Consejo Nacional de Investigaciones Científicas y Técnicas de la Argentina (Conicet así como, en el ámbito internacional, en la International Law Association, en el marco del proyecto Legal Aspects of the Privatisation and Commercialisation of Space Activities: Remote Sensing, National Space Legislation and Registration, Considerada como una investigación de alcance internacional. Uno de los temas centrales se fundamenta en los aspectos jurídicos y conexos de la utilización de satélites de observación de la tierra, sus aplicaciones y dilemas, y la validez de los principios de las Naciones Unidas sobre Teleobservación de la tierra (1986 en el escenario internacional de hoy. Los avances se desarrollan sobre el análisis del nuevo escenario internacional comparándose posiciones –y fundamentos– que proponen un marco más preciso para los principios de 1986, reemplazándolos por un instrumento internacional vinculante. Se advierte la comercialización creciente de la actividad espacial en estos tiempos y consecuente atenuación de la rigidez de reclamos de soberanía que ceden espacio al aspecto comercial de la actividad. En este contexto, los principios se van transformando en normas de la costumbre y se pone acento en un problema de actualidad: la validez ante los tribunales, como medio de prueba, de la información obtenida por tecnologías espaciales.AbstractThis paper advances on recent research directed by the author in the Scientific Investigations National Council in Argentina, as well as in the international scenario, in the International Law Association, in the frame of the project entitled, Legal Aspects of the Privatization and Commercialization of Space Activities: Remote Sensing, National Space Legislation and Registration, considered as a research of international reach. One of the central themes is based upon the judicial aspects and

  5. Entomopathogens Isolated from Invasive Ants and Tests of Their Pathogenicity

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    Maria Fernanda Miori de Zarzuela

    2012-01-01

    Full Text Available Some ant species cause severe ecological and health impact in urban areas. Many attempts have been tested to control such species, although they do not always succeed. Biological control is an alternative to chemical control and has gained great prominence in research, and fungi and nematodes are among the successful organisms controlling insects. This study aimed to clarify some questions regarding the biological control of ants. Invasive ant species in Brazil had their nests evaluated for the presence of entomopathogens. Isolated entomopathogens were later applied in colonies of Monomorium floricola under laboratory conditions to evaluate their effectiveness and the behavior of the ant colonies after treatment. The entomopathogenic nematodes Heterorhabditis sp. and Steinernema sp. and the fungi Beauveria bassiana, Metarhizium anisopliae, and Paecilomyces sp. were isolated from the invasive ant nests. M. floricola colonies treated with Steinernema sp. and Heterorhabditis sp. showed a higher mortality of workers than control. The fungus Beauveria bassiana caused higher mortality of M. floricola workers. However, no colony reduction or elimination was observed in any treatment. The defensive behaviors of ants, such as grooming behavior and colony budding, must be considered when using fungi and nematodes for biological control of ants.

  6. The diversity of microorganisms associated with Acromyrmex leafcutter ants

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    Boomsma Jacobus J

    2002-05-01

    Full Text Available Abstract Background Molecular biological techniques are dramatically changing our view of microbial diversity in almost any environment that has so far been investigated. This study presents a systematic survey of the microbial diversity associated with a population of Acromyrmex leafcutter ants. In contrast to previous studies on social insects, which targeted specific groups of symbionts occurring in the gut (termites, Tetraponera ants or in specialised cells (Camponotus ants the objective of our present study was to do a total screening of all possible micro-organisms that can be found inside the bodies of these leafcutter ants. Results We amplified, cloned and sequenced SSU rRNA encoding gene fragments from 9 microbial groups known to have insect-associated representatives, and show that: (1 representatives of 5 out of 9 tested groups are present, (2 mostly several strains per group are present, adding up to a total of 33 different taxa. We present the microbial taxa associated with Acromymex ants in a phylogenetic context (using sequences from GenBank to assess and illustrate to which known microorganisms they are closely related. The observed microbial diversity is discussed in the light of present knowledge on the evolutionary history of Acromyrmex leafcutter ants and their known mutualistic and parasitic symbionts. Conclusions The major merits of the screening approach documented here is its high sensitivity and specificity, which allowed us to identify several microorganisms that are promising candidates for further study of their interactions with Acromyrmex leafcutter ants or their gardens.

  7. USING ANT COMMUNITIES FOR RAPID ASSESSMENT OF TERRESTRIAL ECOSYSTEM HEALTH

    Energy Technology Data Exchange (ETDEWEB)

    Wike, L; Doug Martin, D; Michael Paller, M; Eric Nelson, E

    2007-01-12

    Ecosystem health with its near infinite number of variables is difficult to measure, and there are many opinions as to which variables are most important, most easily measured, and most robust, Bioassessment avoids the controversy of choosing which physical and chemical parameters to measure because it uses responses of a community of organisms that integrate all aspects of the system in question. A variety of bioassessment methods have been successfully applied to aquatic ecosystems using fish and macroinvertebrate communities. Terrestrial biotic index methods are less developed than those for aquatic systems and we are seeking to address this problem here. This study had as its objective to examine the baseline differences in ant communities at different seral stages from clear cut back to mature pine plantation as a precursor to developing a bioassessment protocol. Comparative sampling was conducted at four seral stages; clearcut, 5 year, 15 year and mature pine plantation stands. Soil and vegetation data were collected at each site. All ants collected were preserved in 70% ethyl alcohol and identified to genus. Analysis of the ant data indicates that ants respond strongly to the habitat changes that accompany ecological succession in managed pine forests and that individual genera as well as ant community structure can be used as an indicator of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in the mature seral stages was likely related to conditions on the forest floor which favored litter dwelling and cool climate specialists.

  8. Interactions Increase Forager Availability and Activity in Harvester Ants.

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    Evlyn Pless

    Full Text Available Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  9. Competitive assembly of South Pacific invasive ant communities

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    Sarty Megan

    2009-01-01

    Full Text Available Abstract Background The relative importance of chance and determinism in structuring ecological communities has been debated for nearly a century. Evidence for determinism or assembly rules is often evaluated with null models that randomize the occurrence of species in particular locales. However, analyses of the presence or absence of species ignores the potential influence of species abundances, which have long been considered of major importance on community structure. Here, we test for community assembly rules in ant communities on small islands of the Tokelau archipelago using both presence-absence and abundance data. We conducted three sets of analyses on two spatial scales using three years of sampling data from 39 plots on 11 islands. Results First, traditional null model tests showed support for negative species co-occurrence patterns among plots within islands, but not among islands. A plausible explanation for this result is that analyses at larger spatial scales merge heterogeneous habitats that have considerable effects on species occurrences. Second, analyses of ant abundances showed that samples with high ant abundances had fewer species than expected by chance, both within and among islands. One ant species, the invasive yellow crazy ant Anoplolepis gracilipes, appeared to have a particularly strong effect on community structure correlated with its abundance. Third, abundances of most ant species were inversely correlated with the abundances of all other ants at both spatial scales. This result is consistent with competition theory, which predicts species distributions are affected by diffuse competition with suites of co-occurring species. Conclusion Our results support a pluralistic explanation for ant species abundances and assembly. Both stochastic and deterministic processes interact to determine ant community assembly, though abundance patterns clearly drive the deterministic patterns in this community. These deterministic

  10. A atividade curricular e pedagógica dos professores como fonte de tensões e dilemas profissionais: contributo para uma interpelação sobre a profissão docente

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    Ariana Cosme

    2017-01-01

    Full Text Available Las tensiones y dilemas profesionales de los profesores son el objeto de reflexión en el origen de la análisis de dieciséis proyectos de investigación, producidos en Portugal, mediante los cuales se intenta relacionar aquellas tensiones y dilemas con la actividad curricular y pedagógica docente. A partir del trabajo realizado se concluye que la dicha actividad no es objeto de una interpelación explícita en los estudios que circunscriben la actividad docente a la discusión del perfil de los profesores y de su resiliencia profesional. En otra perspectiva, se da importancia a dicha actividad en los estudios proponen un enfoque sistémico de la profesión docente, aunque la existencia de una tensión entre la dimensión relacional y la dimensión curricular y pedagógica, comprendida como una tensión estructurante de la reflexión sobre la naturaleza y fines del trabajo docente, puede ser vista a partir de diferentes lecturas, interpretaciones e implicaciones acerca de la forma de pensar la actividad profesional de los docentes.

  11. ¿Es posible una gestión dinámica de la cooperación en dilemas sociales de gran escala?: el caso de la crisis de electricidad de Colombia de 1992

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    Jorge Andrick Parra Valencia

    2013-01-01

    Full Text Available Este artículo presenta cómo una gestión dinámica de la cooperación puede enfrentar la dependencia a las condiciones iniciales que caracterizan al mecanismo de cooperación basado en la confianza, lo que permitiría promover y sostener la cooperación con la que los grupos pueden superar los dilemas sociales. Para esto, se elaboró un constructo siguiendo los lineamientos metodológicos de la Dinámica de Sistemas que da cuenta de la gestión de la cooperación aplicada durante la crisis de electricidad de Colombia de 1992. A partir de los resultados, se concluye que la gestión de la cooperación basada en mecanismos dinámicos es posible en dilemas de gran escala y puede ser utilizada para hacer efectiva y sostenible la cooperación basada en la confianza en dichas situaciones.

  12. LA POLITICA Y LO POLITICO: DEL DILEMA AL PROBLEMA. Análisis de las argumentaciones y propuestas de acción de jóvenes estudiantes de la Ciudad de Buenos Aires

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    Miriam Kriger

    2015-01-01

    Full Text Available El artículo presenta hallazgos de un estudio realizado en BuenosAires y Conurbano sobre las representaciones de “la política” y“lo político” de jóvenes estudiantes. Tomando como punto departida el antagonismo hallado entre ellas en el contextoposterior a la crisis del 2001, proponemos indagar si en laactualidad se ha producido una re articulación ligada a unamayor politización. Se analizan los argumentos surgidos de ladiscusión grupal en torno al planteo de un dilema moral,enfatizando en los sentidos, valoraciones, posicionamientos yactitudes hacia la política como concepto ideal y prácticasituada. Encontramos mayor confianza en la “’política’” comoherramienta de construcción social, a la vez que persiste unaconcesión antipolítica fundada en la desconfianza hacia lospolíticos y las prácticas facciosas. Finalmente, se muestra quecuando el dilema es problematizado reflexivamente, se accede aun mayor pensamiento político y comprensión de los vínculosentre ciudadanía y clase política.

  13. Evolution of Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    The attine ant symbiosis is characterized by ancient but varying degrees of diffuse co-evolution between the ants and their fungal cultivars. Domesticated fungi became dependent on vertical transmission by queens and the ant colonies came to rely on their symbiotic fungus for food and thus...... as garden substrate, whereas the more basal genera use leaf litter, insect feces and insect carcasses. We hypothesized that enzyme activity of fungal symbionts has co-evolved with substrate use and we measured enzyme activities of fungus gardens in the field to test this, focusing particularly on plant...... essential for the symbiosis in general, but have contributed specifically to the evolution of the symbiosis....

  14. Comparative studies of the secretome of fungus-growing ants

    DEFF Research Database (Denmark)

    Linde, Tore; Grell, Morten Nedergaard; Schiøtt, Morten

    2009-01-01

    Leafcutter ants of the species Acromyrmex echinatior live in symbiosis with the fungus Leucoagaricus gongylophorus. The ants harvest fragments of leaves and carry them to the nest where they place the material on the fungal colony. The fungus secretes a wide array of proteins to degrade the leaves...... into nutrients that the ants can feed on. The focus of this study is to discover, characterize and compare the secreted proteins. In order to do so cDNA libraries are constructed from mRNA extracted from the fungus material. The most efficient technology to screen cDNA libraries selectively for secreted...

  15. Warehouse stocking optimization based on dynamic ant colony genetic algorithm

    Science.gov (United States)

    Xiao, Xiaoxu

    2018-04-01

    In view of the various orders of FAW (First Automotive Works) International Logistics Co., Ltd., the SLP method is used to optimize the layout of the warehousing units in the enterprise, thus the warehouse logistics is optimized and the external processing speed of the order is improved. In addition, the relevant intelligent algorithms for optimizing the stocking route problem are analyzed. The ant colony algorithm and genetic algorithm which have good applicability are emphatically studied. The parameters of ant colony algorithm are optimized by genetic algorithm, which improves the performance of ant colony algorithm. A typical path optimization problem model is taken as an example to prove the effectiveness of parameter optimization.

  16. Ant colony algorithm for clustering in portfolio optimization

    Science.gov (United States)

    Subekti, R.; Sari, E. R.; Kusumawati, R.

    2018-03-01

    This research aims to describe portfolio optimization using clustering methods with ant colony approach. Two stock portfolios of LQ45 Indonesia is proposed based on the cluster results obtained from ant colony optimization (ACO). The first portfolio consists of assets with ant colony displacement opportunities beyond the defined probability limits of the researcher, where the weight of each asset is determined by mean-variance method. The second portfolio consists of two assets with the assumption that each asset is a cluster formed from ACO. The first portfolio has a better performance compared to the second portfolio seen from the Sharpe index.

  17. Automating ActionScript Projects with Eclipse and Ant

    CERN Document Server

    Koning, Sidney

    2011-01-01

    Automating repetitive programming tasks is easier than many Flash/AS3 developers think. With the Ant build tool, the Eclipse IDE, and this concise guide, you can set up your own "ultimate development machine" to code, compile, debug, and deploy projects faster. You'll also get started with versioning systems, such as Subversion and Git. Create a consistent workflow for multiple machines, or even complete departments, with the help of extensive Ant code samples. If you want to work smarter and take your skills to a new level, this book will get you on the road to automation-with Ant. Set up y

  18. The invasion biology and sociogenetics of pharaoh ants

    DEFF Research Database (Denmark)

    Schmidt, Anna Mosegaard

    Social insect colonies perform a number of tasks affecting the environments they live in. Some unintentionally introduced species have attracted the attention of scientists and general public alike when causing a number of changes to the composition and functioning of ecosystems. Such ?invaders...... laboratory lineages, thus building the foundation for future research on the species. In addition, I have started a selection experiment (still ongoing in collaboration with Dr. T. Linksvayer) using pharaoh ants, which is the first time artificial selection is attempted in an ant species. Pharaoh ants have...

  19. Exigencias laborales psicológicas percibidas por médicos especialistas hospitalarios Job stress perceived by hospital medical staff

    Directory of Open Access Journals (Sweden)

    V. Escribà-Agüir

    2002-12-01

    Full Text Available Objetivo: Identificar los factores de riesgo psicosocial, que hacen referencia a las exigencias psicológicas, percibidos por los médicos especialistas de seis hospitales públicos de la provincia de Valencia. Métodos: Estudio realizado mediante metodología cualitativa. La población estudiada ha sido personal facultativo especialista hospitalario (medicina interna, oncología, traumatología, unidad de cuidados intensivos [UCI] y radiología de seis hospitales públicos de la provincia de Valencia. Una encuestadora especializada llevó a cabo 47 entrevistas semiestructuradas de manera individual y presencial. Las variables estructurales que se tuvieron en cuenta para la elección de los participantes en el estudio fueron: el sexo, la edad, el estado civil, las cargas familiares, la especialidad médica, la categoría profesional, la antigüedad profesional y el tipo de contrato. Las entrevistas fueron grabadas en audio y posteriormente transcritas. Finalmente, se realizó un análisis del contenido del discurso. Resultados: Los principales factores de riesgo psicosocial expresados por los participantes son la sobrecarga de trabajo y la falta de personal, debidas fundamentalmente a las características organizativas del trabajo del hospital. Otro elemento estresante es el contacto diario con el sufrimiento y con la muerte, así como el hecho de sentirse responsable de vidas humanas. Las relaciones interpersonales en el entorno laboral, en el caso de los familiares de los pacientes, constituyen también un factor de riesgo psicosocial destacable, así como la incertidumbre ante el diagnóstico y el tratamiento, las posibilidades de ser demandado por mala práctica y el tener que transmitir malas noticias. Conclusiones: El personal facultativo hospitalario expresa un alto número de factores de riesgo psicosocial. Algunos están relacionados específicamente con las características de la profesión médica (contacto con el sufrimiento y con la

  20. Perfeccionismo positivo / negativo y calidad de vida percibida en estudiantes de Psicología, Medicina e Ingeniería de la Ciudad de Buenos Aires Positive / negative perfectionism and perceived quality of life in Psychology, Medicine and Engineering students of the city of Buenos Aires

    Directory of Open Access Journals (Sweden)

    Fernán Guido Arana

    2010-12-01

    Full Text Available El objetivo del presente estudio es dar cuenta de la relación entre el perfeccionismo en sus tres dimensiones (Altos Estándares -AE-, Orden -O- y Discrepancia-D- y la calidad de vida percibida (CV en tres muestras de estudiantes universitarios de las carreras de Psicología, Medicina e Ingeniería de la Ciudad de Buenos Aires. La muestra estuvo conformada por 476 estudiantes que completaron los siguientes instrumentos: cuestionario sociodemográfico, la almost Perfect Scale-revised (APS-R, Slaney, Rice, Mobley, Trippi, & Ashby, 2001; adaptación: Arana, Keegan, & Rutsztein, 2009 y el Inventario de Calidad de Vida Percibida (ICV, Mikulic, 2006. Los resultados sugieren una asociación signiicativa para un aspecto del perfeccionismo positivo (O y una alta CV percibida, y para el perfeccionismo negativo (D en relación a una baja CV percibida. Diferencias halladas en las diversas carreras para estas dimensiones indican la necesidad de atender a las variables contextuales especíicas para el análisis de este constructo.The aim of this study is to account for the relationship between perfectionism in its three dimensions (High Standards -HS-, Order -O-, and Discrepancy -D- and the perceived quality of life (QL in three samples of university students of Psychology, Medicine and Engineering of the City of Buenos Aires. The sample consisted of 476 students who completed the following in struments: Socio-demographic questionnaire, the Almost Perfect Scale-revised (APS-R, Slaney, Rice, Mobley, Trippi, & Ashby, 2001; adaptation: Arana, Keegan, & Rutsztein, 2009 and the Inventario de Calidad de Vida Percibida (ICV, Mikulic, 2006. Results suggest a signiicant association for one aspect of positive perfectionism (O and a perceived high QL, and for negative perfectionism (D and a perceived low QL. Differences found for these dimensions in the students of each career indicate the need to pay attention to specific contextual variables for the analysis of this

  1. Symbiotic mutualism with a community of opportunistic ants: protection, competition, and ant occupancy of the myrmecophyte Barteria nigritana (Passifloraceae)

    Science.gov (United States)

    Djiéto-Lordon, Champlain; Dejean, Alain; Gibernau, Marc; Hossaert-McKey, Martine; McKey, Doyle

    2004-10-01

    Barteria nigritana is a myrmecophyte tree of Lower Guinea coastal vegetation. Unlike the more specialised B. fistulosa, which harbours a single host-specific mutualistic ant, B. nigritana is associated with several opportunistic ants. Such symbiotic, yet opportunistic, ant-plant associations have been little studied. On 113 clumps of B. nigritana, we censused ant associates and herbivores and compared herbivory on plants occupied by different ants. In addition to these correlative data, protection conferred by different ant species was compared by herbivore-placement experiments. Identity of ant associate changed predictably over plant ontogeny. Pheidole megacephala was restricted to very small plants; saplings were occupied by either Oecophylla longinoda or Crematogaster sp., and the latter species was the sole occupant of larger trees. Damage by caterpillars of the nymphalid butterfly Acraea zetes accounted for much of the herbivory to leaves. Ant species differed in the protection provided to hosts. While P. megacephala provided no significant protection, plants occupied by O. longinoda and Crematogaster sp. suffered less damage than did unoccupied plants or those occupied by P. megacephala. Furthermore, O. longinoda provided more effective protection than did Crematogaster sp. Herbivore-placement experiments confirmed these results. Workers of O. longinoda killed or removed all larval instars of A. zetes. Crematogaster preyed on only the two first larval instars, and P. megacephala preyed mainly on eggs, only rarely attacking the two first larval instars. Opportunistic ants provided significant protection to this relatively unspecialised myrmecophyte. The usual associate of mature trees was not the species that provided most protection.

  2. Selenium exposure results in reduced reproduction in an invasive ant species and altered competitive behavior for a native ant species

    International Nuclear Information System (INIS)

    De La Riva, Deborah G.; Trumble, John T.

    2016-01-01

    Competitive ability and numerical dominance are important factors contributing to the ability of invasive ant species to establish and expand their ranges in new habitats. However, few studies have investigated the impact of environmental contamination on competitive behavior in ants as a potential factor influencing dynamics between invasive and native ant species. Here we investigated the widespread contaminant selenium to investigate its potential influence on invasion by the exotic Argentine ant, Linepithema humile, through effects on reproduction and competitive behavior. For the fecundity experiment, treatments were provided to Argentine ant colonies via to sugar water solutions containing one of three concentrations of selenium (0, 5 and 10 μg Se mL −1 ) that fall within the range found in soil and plants growing in contaminated areas. Competition experiments included both the Argentine ant and the native Dorymyrmex bicolor to determine the impact of selenium exposure (0 or 15 μg Se mL −1 ) on exploitation- and interference-competition between ant species. The results of the fecundity experiment revealed that selenium negatively impacted queen survival and brood production of Argentine ants. Viability of the developing brood was also affected in that offspring reached adulthood only in colonies that were not given selenium, whereas those in treated colonies died in their larval stages. Selenium exposure did not alter direct competitive behaviors for either species, but selenium exposure contributed to an increased bait discovery time for D. bicolor. Our results suggest that environmental toxins may not only pose problems for native ant species, but may also serve as a potential obstacle for establishment among exotic species. - Highlights: • Argentine ant colonies exposed to selenium had reduced fecundity compared to unexposed colonies. • Viability of offspring was negatively impacted by selenium. • Queen survival was reduced in colonies

  3. The introduction history of invasive garden ants in Europe: integrating genetic, chemical and behavioural approaches

    DEFF Research Database (Denmark)

    Ugelvig, Line; Drijfhout, Falko; Kronauer, Daniel

    2008-01-01

    BACKGROUND: The invasive garden ant, Lasius neglectus, is the most recently detected pest ant and the first known invasive ant able to become established and thrive in the temperate regions of Eurasia. In this study, we aim to reconstruct the invasion history of this ant in Europe analysing 14 po...

  4. Stealthy invaders: the biology of Cardiocondyla tramp ants

    DEFF Research Database (Denmark)

    Heinze, J.; Cremer, Sylvia; Eckl, N.

    2006-01-01

    Many invasive ant species, such as the Argentine ant or the red imported fire ant, have huge colonies with thousands of mass-foraging workers, which quickly monopolise resources and therefore represent a considerable threat to the native ant fauna. Cardiocondyla obscurior and several other specie...

  5. FMR measurements in fire ants: evidence of magnetic material

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, Darci M.S.; Acosta-Avalos, Daniel; El-Jaick, Lea J.; Cunha, Alexandra D.M.; Malheiros, Maria G.; Wajnberg, Eliane [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Linhares, Marilia P. [Centro de Ciencias do Estado, do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

    1998-01-01

    Based on the behavioral and the localization of iron-containing tissue fire ants were examined by EPR for magnetic material. Results suggest the presence of magnetite particles. (author) 12 refs., 1 fig.

  6. Disease dynamics in a specialized parasite of ant societies.

    Directory of Open Access Journals (Sweden)

    Sandra B Andersen

    Full Text Available Coevolution between ant colonies and their rare specialized parasites are intriguing, because lethal infections of workers may correspond to tolerable chronic diseases of colonies, but the parasite adaptations that allow stable coexistence with ants are virtually unknown. We explore the trade-offs experienced by Ophiocordyceps parasites manipulating ants into dying in nearby graveyards. We used field data from Brazil and Thailand to parameterize and fit a model for the growth rate of graveyards. We show that parasite pressure is much lower than the abundance of ant cadavers suggests and that hyperparasites often castrate Ophiocordyceps. However, once fruiting bodies become sexually mature they appear robust. Such parasite life-history traits are consistent with iteroparity--a reproductive strategy rarely considered in fungi. We discuss how tropical habitats with high biodiversity of hyperparasites and high spore mortality has likely been crucial for the evolution and maintenance of iteroparity in parasites with low dispersal potential.

  7. Sperm length evolution in the fungus-growing ants

    DEFF Research Database (Denmark)

    Baer, B.; Dijkstra, M. B.; Mueller, U. G.

    2009-01-01

    -growing ants, representing 9 of the 12 recognized genera, and mapped these onto the ant phylogeny. We show that average sperm length across species is highly variable and decreases with mature colony size in basal genera with singly mated queens, suggesting that sperm production or storage constraints affect...... the evolution of sperm length. Sperm length does not decrease further in multiply mating leaf-cutting ants, despite substantial further increases in colony size. In a combined analysis, sexual dimorphism explained 63.1% of the variance in sperm length between species. As colony size was not a significant...... predictor in this analysis, we conclude that sperm production trade-offs in males have been the major selective force affecting sperm length across the fungus-growing ants, rather than storage constraints in females. The relationship between sperm length and sexual dimorphism remained robust...

  8. Myrmeciza and related antbirds (Aves, Formicariidae as army ant followers

    Directory of Open Access Journals (Sweden)

    Edwin O. Willis

    1984-01-01

    Full Text Available Antbirds of the genera Myrmeciza (including Sipia and Myrmoborus, Gymnocichla, and Sclateria hop near or on the ground in fairly dense vegetation, "pounding" their tails downward. Where dense understory vegetation is widespread and ants move in it for long distances, certain of these antbirds become regular ant followers: M. immaculata and M. fortis in cluttered moist foothill forest from Costa Rica to upper Amazonia; Gymnocichla nudiceps in moist cluttered second growth of Central America to Colombia. Where the forest understory is more open, Myrmeciza species follow ants mainly in cluttered patches: M. exsul in lowland forest west of the Andes, M. myotherina east of the Andes. Myrmeciza or relatives that specialize on water-edge or very dense zones rarely follow ants.

  9. Ants farm subterranean aphids mostly in single clone groups

    DEFF Research Database (Denmark)

    Ivens, Aniek B.F.; Kronauer, Daniel Jan Christoph; Pen, Ido

    2012-01-01

    mutualisms have been studied in sufficient genetic detail to address these issues, so we decided to characterize symbiont diversity in the complex mutualism between multiple root aphid species and Lasius flavus ants. After showing elsewhere that three of these aphid species have low dispersal and mostly...... if not exclusively asexual reproduction, we here investigate aphid diversity within and between ant nest mounds. Results The three focal species (Geoica utricularia, Forda marginata and Tetraneura ulmi) had considerable clonal diversity at the population level. Yet more than half of the ant mounds contained just....... The ants appear to eat most of the early instar aphids, so that adult aphids are unlikely to face limited phloem resources and scramble competition with other aphids. We suggest that such culling of carbohydrate-providing symbionts for protein ingestion may maintain maximal host yield per aphid while also...

  10. Ant groups optimally amplify the effect of transiently informed individuals

    Science.gov (United States)

    Gelblum, Aviram; Pinkoviezky, Itai; Fonio, Ehud; Ghosh, Abhijit; Gov, Nir; Feinerman, Ofer

    2015-07-01

    To cooperatively transport a large load, it is important that carriers conform in their efforts and align their forces. A downside of behavioural conformism is that it may decrease the group's responsiveness to external information. Combining experiment and theory, we show how ants optimize collective transport. On the single-ant scale, optimization stems from decision rules that balance individuality and compliance. Macroscopically, these rules poise the system at the transition between random walk and ballistic motion where the collective response to the steering of a single informed ant is maximized. We relate this peak in response to the divergence of susceptibility at a phase transition. Our theoretical models predict that the ant-load system can be transitioned through the critical point of this mesoscopic system by varying its size; we present experiments supporting these predictions. Our findings show that efficient group-level processes can arise from transient amplification of individual-based knowledge.

  11. Florida alternative NTCIP testing software (ANTS) for actuated signal controllers.

    Science.gov (United States)

    2009-01-01

    The scope of this research project did include the development of a software tool to test devices for NTCIP compliance. Development of the Florida Alternative NTCIP Testing Software (ANTS) was developed by the research team due to limitations found w...

  12. Novel fungal disease in complex leaf-cutting ant societies

    DEFF Research Database (Denmark)

    Hughes, David Peter; Evans, Harry C.; Hywel-Jones, Nigel

    2009-01-01

    1. The leaf-cutting ants practise an advanced system of mycophagy where they grow a fungus as a food source. As a consequence of parasite threats to their crops, they have evolved a system of morphological, behavioural, and chemical defences, particularly against fungal pathogens (mycopathogens). 2....... Specific fungal diseases of the leaf-cutting ants themselves have not been described, possibly because broad spectrum anti-fungal defences against mycopathogens have reduced their susceptibility to entomopathogens. 3. Using morphological and molecular tools, the present study documents three rare infection...... events of Acromyrmex and Atta leaf-cutting ants by Ophiocordyceps fungi, agenus of entomopathogens that is normally highly specific in its host choice. 4. As leaf-cutting ants have been intensively studied, the absence of prior records of Ophiocordyceps suggests that these infections may be a novel event...

  13. Heavy metal pollution disturbs immune response in wild ant populations

    International Nuclear Information System (INIS)

    Sorvari, Jouni; Rantala, Liisa M.; Rantala, Markus J.; Hakkarainen, Harri; Eeva, Tapio

    2007-01-01

    Concern about the effects of environmental contaminants on immune function in both humans and wildlife is growing and practically nothing is known about this impact on terrestrial invertebrates, even though they are known to easily accumulate pollutants. We studied the effect of industrial heavy metal contamination on immune defense of a free-living wood ant (Formica aquilonia). To find out whether ants show an adapted immune function in a polluted environment, we compared encapsulation responses between local and translocated colonies. Local colonies showed higher heavy metal levels than the translocated ones but the encapsulation response was similar between the two groups, indicating that the immune system of local ants has not adapted to high contamination level. The encapsulation response was elevated in moderate whereas suppressed in high heavy metal levels suggesting higher risk for infections in heavily polluted areas. - Heavy metal pollution affects immune function in ants

  14. Ant colony search algorithm for optimal reactive power optimization

    Directory of Open Access Journals (Sweden)

    Lenin K.

    2006-01-01

    Full Text Available The paper presents an (ACSA Ant colony search Algorithm for Optimal Reactive Power Optimization and voltage control of power systems. ACSA is a new co-operative agents’ approach, which is inspired by the observation of the behavior of real ant colonies on the topic of ant trial formation and foraging methods. Hence, in the ACSA a set of co-operative agents called "Ants" co-operates to find good solution for Reactive Power Optimization problem. The ACSA is applied for optimal reactive power optimization is evaluated on standard IEEE, 30, 57, 191 (practical test bus system. The proposed approach is tested and compared to genetic algorithm (GA, Adaptive Genetic Algorithm (AGA.

  15. application of ant colony optimisation in distribution transformer sizing

    African Journals Online (AJOL)

    HP

    Keywords: ant colony, optimization, transformer sizing, distribution transformer. 1. INTRODUCTION ... more intensive pheromone and higher probability to be chosen [12]. ..... pp.29-41, 1996. [7] EC global market place, “Technical Parameters”,.

  16. Capacidad de una medida de inflación percibida para predecir el índice de confianza del consumidor, las expectativas de inflación y la inflación en costa rica, 2006-2012

    Directory of Open Access Journals (Sweden)

    Diego Agüero-Morera

    2016-12-01

    Full Text Available En este estudio se construyó el Índice de Precios Percibidos al Comprador (IPPC para estimar la inflación percibida en Costa Rica de julio 2006 a diciembre 2012. Con base en los fundamentos teóricos de Brachinger (2006,2008, se modificó la metodología del índice de Precios del Consumidor (IPC, dándole un mayor peso a los bienes de la canasta que se compran con más frecuencia. Se utilizó el IPPC para estimar modelos ARMA y ARDL, donde se evidenció una buena capacidad de pronóstico para el IPC de estratos bajos y las expectativas de inflación. Al comparar el IPC y el IPPC, la diferencia relativa entre los dos índices tiende a ser superior para niveles más altos de inflación, siendo mayor el índice propuesto. Además, artículos comprados semanalmente como la gasolina, el casado y el transporte en taxi predominan en la media de la variación interanual mensual del IPPC; mientras que el peso de bienes comprados semestral o anualmente es prácticamente nulo.

  17. Relación entre calidad percibida y afinidad emocional de imágenes arquitectónicas en función del dispositivo de visualización. Recomendaciones para su uso docente.

    Directory of Open Access Journals (Sweden)

    Ernest Redondo

    2013-06-01

    Full Text Available En la educación universitaria en general y especialmente la relacionada con la arquitectura, el uso de imágenes digitales está generalizado. No obstante, dicho uso dista de estar optimizado ya que tanto alumnos como profesores ignoran sistemáticamente conceptos clave como las características del medio de visualizado o el usuario final. La tendencia general es la creación de imágenes con elevadas resoluciones, aspecto que conlleva ficheros de elevado tamaño que generan elevados tiempos de carga, edición o transmisión. El presente trabajo analiza cómo afecta el nivel de calidad percibida de la imagen en función de las características de esta y del dispositivo en el que se visualiza, y su relación con la respuesta emocional del usuario. La novedad de la metodología empírica empleada radica en la evaluación de usuarios en el ámbito universitario con técnicas propias de la sociología y la psicología, desde un enfoque propio de los estudios de comunicación audiovisual.

  18. Teoría de la Acción Planeada y tasa de ejercicio percibida: un modelo predictivo en estudiantes adolescentes de educación física

    Directory of Open Access Journals (Sweden)

    Elisa Huéscar

    2014-05-01

    Full Text Available Este estudio se planteó como objetivo analizar algunos factores que influyen en la percepción de la tasa de ejercicio de estudiantes adolescentes españoles tomando como marco la teoría de la acción planeada (Ajzen, 1991. Participaron 698 estudiantes en clases de educación física que completaron el Cuestionario de la teoría de la conducta planeada (TCP y el Cuestionario de Actividad Física Habitual. Los resultados del modelo de ecuaciones estructurales mostraron que la actitud, norma subjetiva y control de la teoría de la conducta planeada predecían positivamente la intención futura de practicar ejercicio físico, que, a su vez, predecía positivamente la tasa de ejercicio físico percibida por el adolescente. Los resultados de este estudio ofrecen apoyo a la teoría de la conducta planeada y destacan los beneficios de promover la práctica de ejercicio físico-deportivo a través del apoyo de los antecedentes motivacionales, actitud, norma subjetiva y control en la etapa de la adolescencia, dada la importancia de esta fase evolutiva en la instauración de hábitos saludables en los jóvenes.

  19. Fluid intake rates in ants correlate with their feeding habits.

    Science.gov (United States)

    Paul, J; Roces, F

    2003-04-01

    This study investigates the techniques of nectar feeding in 11 different ant species, and quantitatively compares fluid intake rates over a wide range of nectar concentrations in four species that largely differ in their feeding habits. Ants were observed to employ two different techniques for liquid food intake, in which the glossa works either as a passive duct-like structure (sucking), or as an up- and downwards moving shovel (licking). The technique employed for collecting fluids at ad libitum food sources was observed to be species-specific and to correlate with the presence or absence of a well-developed crop in the species under scrutiny. Workers of ponerine ants licked fluid food during foraging and transported it as a droplet between their mandibles, whereas workers of species belonging to phylogenetically more advanced subfamilies, with a crop capable of storing liquids, sucked the fluid food, such as formicine ants of the genus Camponotus. In order to evaluate the performance of fluid collection during foraging, intake rates for sucrose solutions of different concentrations were measured in four ant species that differ in their foraging ecology. Scaling functions between fluid intake rates and ant size were first established for the polymorphic species, so as to compare ants of different size across species. Results showed that fluid intake rate depended, as expected and previously reported in the literature, on sugar concentration and the associated fluid viscosity. It also depended on both the species-specific feeding technique and the extent of specialization on foraging on liquid food. For similarly-sized ants, workers of two nectar-feeding ant species, Camponotus rufipes (Formicinae) and Pachycondyla villosa (Ponerinae), collected fluids with the highest intake rates, while workers of the leaf-cutting ant Atta sexdens (Myrmicinae) and a predatory ant from the Rhytidoponera impressa-complex (Ponerinae) did so with the lowest rate. Calculating the

  20. Climatic warming destabilizes forest ant communities.

    Science.gov (United States)

    Diamond, Sarah E; Nichols, Lauren M; Pelini, Shannon L; Penick, Clint A; Barber, Grace W; Cahan, Sara Helms; Dunn, Robert R; Ellison, Aaron M; Sanders, Nathan J; Gotelli, Nicholas J

    2016-10-01

    How will ecological communities change in response to climate warming? Direct effects of temperature and indirect cascading effects of species interactions are already altering the structure of local communities, but the dynamics of community change are still poorly understood. We explore the cumulative effects of warming on the dynamics and turnover of forest ant communities that were warmed as part of a 5-year climate manipulation experiment at two sites in eastern North America. At the community level, warming consistently increased occupancy of nests and decreased extinction and nest abandonment. This consistency was largely driven by strong responses of a subset of thermophilic species at each site. As colonies of thermophilic species persisted in nests for longer periods of time under warmer temperatures, turnover was diminished, and species interactions were likely altered. We found that dynamical (Lyapunov) community stability decreased with warming both within and between sites. These results refute null expectations of simple temperature-driven increases in the activity and movement of thermophilic ectotherms. The reduction in stability under warming contrasts with the findings of previous studies that suggest resilience of species interactions to experimental and natural warming. In the face of warmer, no-analog climates, communities of the future may become increasingly fragile and unstable.

  1. Recognition in ants: social origin matters.

    Directory of Open Access Journals (Sweden)

    Joël Meunier

    Full Text Available The ability of group members to discriminate against foreigners is a keystone in the evolution of sociality. In social insects, colony social structure (number of queens is generally thought to influence abilities of resident workers to discriminate between nestmates and non-nestmates. However, whether social origin of introduced individuals has an effect on their acceptance in conspecific colonies remains poorly explored. Using egg-acceptance bioassays, we tested the influence of social origin of queen-laid eggs on their acceptance by foreign workers in the ant Formica selysi. We showed that workers from both single- and multiple-queen colonies discriminated against foreign eggs from single-queen colonies, whereas they surprisingly accepted foreign eggs from multiple-queen colonies. Chemical analyses then demonstrated that social origins of eggs and workers could be discriminated on the basis of their chemical profiles, a signal generally involved in nestmate discrimination. These findings provide the first evidence in social insects that social origins of eggs interfere with nestmate discrimination and are encoded by chemical signatures.

  2. Nasa's Ant-Inspired Swarmie Robots

    Science.gov (United States)

    Leucht, Kurt W.

    2016-01-01

    As humans push further beyond the grasp of earth, robotic missions in advance of human missions will play an increasingly important role. These robotic systems will find and retrieve valuable resources as part of an in-situ resource utilization (ISRU) strategy. They will need to be highly autonomous while maintaining high task performance levels. NASA Kennedy Space Center has teamed up with the Biological Computation Lab at the University of New Mexico to create a swarm of small, low-cost, autonomous robots to be used as a ground-based research platform for ISRU missions. The behavior of the robot swarm mimics the central-place foraging strategy of ants to find and collect resources in a previously unmapped environment and return those resources to a central site. This talk will guide the audience through the Swarmie robot project from its conception by students in a New Mexico research lab to its robot trials in an outdoor parking lot at NASA. The software technologies and techniques used on the project will be discussed, as well as various challenges and solutions that were encountered by the development team along the way.

  3. Carbohydrate supply limits invasion of natural communities by Argentine ants.

    Science.gov (United States)

    Rowles, Alexei D; Silverman, Jules

    2009-08-01

    The ability of species to invade new habitats is often limited by various biotic and physical factors or interactions between the two. Invasive ants, frequently associated with human activities, flourish in disturbed urban and agricultural environments. However, their ability to invade and establish in natural habitats is more variable. This is particularly so for the invasive Argentine ant (Linepithema humile). While biotic resistance and low soil moisture limits their invasion of natural habitats in some instances, the effect of food availability has been poorly explored. We conducted field experiments to determine if resource availability limits the spread and persistence of Argentine ants in remnant natural forest in North Carolina. Replicated transects paired with and without sucrose solution feeding stations were run from invaded urban edges into forest remnants and compared over time using baits and direct counts at feeding stations. Repeated under different timing regimes in 2006 and 2007, access to sucrose increased local Argentine ant abundances (1.6-2.5 fold) and facilitated their progression into the forest up to 73 +/- 21% of 50-m transects. Resource removal caused an expected decrease in Argentine ant densities in 2006, in conjunction with their retreat to the urban/forest boundary. However, in 2007, Argentine ant numbers unexpectedly continued to increase in the absence of sugar stations, possibly through access to alternative resources or conditions not available the previous year such as honeydew-excreting Hemiptera. Our results showed that supplementing carbohydrate supply facilitates invasion of natural habitat by Argentine ants. This is particularly evident where Argentine ants continued to thrive following sugar station removal.

  4. Hybridization in East African swarm-raiding army ants

    DEFF Research Database (Denmark)

    Kronauer, Daniel Jc; Peters, Marcell K; Schöning, Caspar

    2011-01-01

    Hybridization can have complex effects on evolutionary dynamics in ants because of the combination of haplodiploid sex-determination and eusociality. While hybrid non-reproductive workers have been found in a range of species, examples of gene-flow via hybrid queens and males are rare. We studied...... hybridization in East African army ants (Dorylus subgenus Anomma) using morphology, mitochondrial DNA sequences, and nuclear microsatellites....

  5. An Improved Ant Colony Matching by Using Discrete Curve Evolution

    OpenAIRE

    Saadi, Younes; Sari, Eka,; Herawan, Tutut

    2014-01-01

    Part 1: Information & Communication Technology-EurAsia Conference 2014, ICT-EurAsia 2014; International audience; In this paper we present an improved Ant Colony Optimization (ACO) for contour matching, which can be used to match 2D shapes. Discrete Curve Evolution (DCE) technique is used to simplify the extracted contour. In order to find the best correspondence between shapes, the match process is formulated as a Quadratic Assignment Problem (QAP) and resolved by using Ant Colony Optimizati...

  6. Behavior of ergatoid males in the ant, Cardiocondyla nuda

    OpenAIRE

    Heinze, Jürgen; Künholz, S.; Schilder, K.; Hölldobler, B.

    1993-01-01

    Ergatoid males of the ant, Cardiocondyla nuda, attack and frequently kill young males during or shortly after eclosion. Smaller colonies therefore contain typically only one adult male, which may inseminate all alate queens which are reared in the colony over a few weeks. In larger colonies, several males may be present, however, fighting among adult males was not observed. We discuss the significance of male fighting behavior in ants.

  7. Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging

    Science.gov (United States)

    Suckling, D.M.; Peck, R.W.; Stringer, L.D.; Snook, K.; Banko, P.C.

    2010-01-01

    Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2-3 m s-1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. ?? Springer Science+Business Media, LLC 2010.

  8. No sex in fungus-farming ants or their crops.

    Science.gov (United States)

    Himler, Anna G; Caldera, Eric J; Baer, Boris C; Fernández-Marín, Hermógenes; Mueller, Ulrich G

    2009-07-22

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi for food. Degenerate female mating anatomy, extensive field and laboratory surveys, and DNA fingerprinting implicate complete asexuality in this widespread ant species. Maternally inherited bacteria (e.g. Wolbachia, Cardinium) and the fungal cultivars can be ruled out as agents inducing asexuality. M. smithii societies of clonal females provide a unique system to test theories of parent-offspring conflict and reproductive policing in social insects. Asexuality of both ant farmer and fungal crop challenges traditional views proposing that sexual farmer ants outpace coevolving sexual crop pathogens, and thus compensate for vulnerabilities of their asexual crops. Either the double asexuality of both farmer and crop may permit the host to fully exploit advantages of asexuality for unknown reasons or frequent switching between crops (symbiont reassociation) generates novel ant-fungus combinations, which may compensate for any evolutionary handicaps of asexuality in M. smithii.

  9. [Ants as carriers of microorganisms in hospital environments].

    Science.gov (United States)

    Pereira, Rogério Dos Santos; Ueno, Mariko

    2008-01-01

    Concern exists regarding the real possibility of public health threats caused by pathogenic agents that are carried by urban ants. The present study had the objective of isolating and identifying the microorganisms that are associated with ants in hospital environments. One hundred and twenty-five ants of the same species were collected from different units of a university hospital. Each ant was collected using a swab soaked with physiological solution and was transferred to a tube containing brain heart infusion broth and incubated at 35 degrees C for 24 hours. From each tube, with growth, inoculations were made into specific culturing media, to isolate any microorganisms. The ants presented a high capacity for carrying microorganism groups: spore-producing Gram-positive bacilli 63.5%, Gram-negative bacilli 6.3%, Gram-positive cocci 23.1%, filamentous fungi 6.7% and yeast 0.5%. Thus, it can be inferred that ants may be one of the agents responsible for disseminating microorganisms in hospital environments.

  10. Species-Specific Effects of Ant Inhabitants on Bromeliad Nutrition.

    Directory of Open Access Journals (Sweden)

    Ana Z Gonçalves

    Full Text Available Predator activities may lead to the accumulation of nutrients in specific areas of terrestrial habitats where they dispose of prey carcasses. In their feeding sites, predators may increase nutrient availability in the soil and favor plant nutrition and growth. However, the translocation of nutrients from one habitat to another may depend on predator identity and diet, as well as on the amount of prey intake. Here we used isotopic (15N and physiological methods in greenhouse experiments to evaluate the effects of the identity of predatory ants (i.e., the consumption of prey and nest sites on the nutrition and growth of the bromeliad Quesnelia arvensis. We showed that predatory ants with protein-based nutrition (i.e., Odontomachus hastatus, Gnamptogenys moelleri improved the performance of their host bromeliads (i.e., increased foliar N, production of soluble proteins and growth. On the other hand, the contribution of Camponotus crassus for the nutritional status of bromeliads did not differ from bromeliads without ants, possibly because this ant does not have arthropod prey as a preferred food source. Our results show, for the first time, that predatory ants can translocate nutrients from one habitat to another within forests, accumulating nutrients in their feeding sites that become available to bromeliads. Additionally, we highlight that ant contribution to plant nutrition may depend on predator identity and its dietary requirements. Nest debris may be especially important for epiphytic and terrestrial bromeliads in nutrient-poor environments.

  11. Reaction of mutualistic and granivorous ants to ulex elaiosome chemicals.

    Science.gov (United States)

    Gammans, Nicola; Bullock, James M; Gibbons, Hannah; Schönrogge, Karsten

    2006-09-01

    It has been proposed that chemicals on plant elaiosomes aid seed detection by seed-dispersing ants. We hypothesized that the chemical interaction between ants and elaiosomes is more intimate than a generic attraction, and that elaiosome chemicals will attract mutualistic but not granivorous ant species. We investigated this by using two gorse species, Ulex minor and U. europaeus, and two associated ant species from European heathlands, the mutualist Myrmica ruginodis and the granivore Tetramorium caespitum. Behavioral studies were conducted with laboratory nests and foraging arenas. Both ants will take Ulex seeds, but while M. ruginodis showed increased antennation toward ether extracts of elaiosome surface chemicals compared with controls, T. caespitum showed no response. Elaiosome extracts were separated into seven lipid fractions. M. ruginodis showed increased antennation only toward the diglyceride fractions of both Ulex species, whereas T. caespitum showed no consistent reaction. This indicates that M. ruginodis can detect the elaiosome by responding to its surface chemicals, but T. caespitum is unresponsive to these chemicals. Responses to surface chemicals could increase the rate of seed detection in the field, and so these results suggest that Ulex elaiosomes produce chemicals that facilitate attraction of mutualistic rather than granivorous ant species. This could reduce seed predation and increase Ulex fitness.

  12. Aversive learning of odor-heat associations in ants.

    Science.gov (United States)

    Desmedt, Lucie; Baracchi, David; Devaud, Jean-Marc; Giurfa, Martin; d'Ettorre, Patrizia

    2017-12-15

    Ants have recently emerged as useful models for the study of olfactory learning. In this framework, the development of a protocol for the appetitive conditioning of the maxilla-labium extension response (MaLER) provided the possibility of studying Pavlovian odor-food learning in a controlled environment. Here we extend these studies by introducing the first Pavlovian aversive learning protocol for harnessed ants in the laboratory. We worked with carpenter ants Camponotus aethiops and first determined the capacity of different temperatures applied to the body surface to elicit the typical aversive mandible opening response (MOR). We determined that 75°C is the optimal temperature to induce MOR and chose the hind legs as the stimulated body region because of their high sensitivity. We then studied the ability of ants to learn and remember odor-heat associations using 75°C as the unconditioned stimulus. We studied learning and short-term retention after absolute (one odor paired with heat) and differential conditioning (a punished odor versus an unpunished odor). Our results show that ants successfully learn the odor-heat association under a differential-conditioning regime and thus exhibit a conditioned MOR to the punished odor. Yet, their performance under an absolute-conditioning regime is poor. These results demonstrate that ants are capable of aversive learning and confirm previous findings about the different attentional resources solicited by differential and absolute conditioning in general. © 2017. Published by The Company of Biologists Ltd.

  13. Competence of Litter Ants for Rapid Biodiversity Assessments

    Directory of Open Access Journals (Sweden)

    T. H. Saumya E. Silva

    2017-01-01

    Full Text Available Rapid Biodiversity Assessment approaches associated with focusing taxa have overcome many of the problems related to large scale surveys. This study examined the suitability of litter ants as a focusing taxon by checking whether diversity and species assemblages of litter ants reflect the overall picture of arthropod diversity and assemblages in leaf litter in two vegetation types: secondary forest and pine plantation in Upper Hanthana forest reserve, Sri Lanka. In each vegetation type, arthropods were sampled using three sampling methods (Winkler extraction, hand collection, and pitfall traps along three 100 m line transects. From the two sites, 1887 litter ants (34 species and 3488 litter arthropods (52 species were collected. Species assemblages composition of both ants and other arthropods differed significantly between the two sites (ANOSIM, p=0.001 with both groups generating distinct clusters for the two sites (SIMPROF, p=0.001. But there was no significant correlation (p>0.05 between abundance and richness of litter ants and those of other arthropods in both vegetation types. The overall finding suggests that the litter ants do not reflect the holistic picture of arthropod diversity and assemblages in leaf litter, but the quality of the habitat for the survival of all litter arthropods.

  14. Water stress strengthens mutualism among ants, trees, and scale insects.

    Directory of Open Access Journals (Sweden)

    Elizabeth G Pringle

    2013-11-01

    Full Text Available Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  15. An invasive slug exploits an ant-seed dispersal mutualism.

    Science.gov (United States)

    Meadley Dunphy, Shannon A; Prior, Kirsten M; Frederickson, Megan E

    2016-05-01

    Plant-animal mutualisms, such as seed dispersal, are often vulnerable to disruption by invasive species. Here, we show for the first time how a non-ant invasive species negatively affects seed dispersal by ants. We examined the effects of several animal species that co-occur in a temperate deciduous forest-including native and invasive seed-dispersing ants (Aphaenogaster rudis and Myrmica rubra, respectively), an invasive slug (Arion subfuscus), and native rodents-on a native myrmecochorous plant, Asarum canadense. We experimentally manipulated ant, slug, and rodent access to seed depots and measured seed removal. We also video-recorded depots to determine which other taxa interact with seeds. We found that A. rudis was the main disperser of seeds and that A. subfuscus consumed elaiosomes without dispersing seeds. Rodent visitation was rare, and rodent exclusion had no significant effect on seed or elaiosome removal. We then used data obtained from laboratory and field mesocosm experiments to determine how elaiosome robbing by A. subfuscus affects seed dispersal by A. rudis and M. rubra. We found that elaiosome robbing by slugs reduced seed dispersal by ants, especially in mesocosms with A. rudis, which picks up seeds more slowly than M. rubra. Taken together, our results show that elaiosome robbing by an invasive slug reduces seed dispersal by ants, suggesting that invasive slugs can have profound negative effects on seed dispersal mutualisms.

  16. Water stress strengthens mutualism among ants, trees, and scale insects.

    Science.gov (United States)

    Pringle, Elizabeth G; Akçay, Erol; Raab, Ted K; Dirzo, Rodolfo; Gordon, Deborah M

    2013-11-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  17. Reforma sanitária brasileira: dilemas entre o instituinte e o instituído Brazilian sanitary reform: dilemmas between the instituing and the institutionalized

    Directory of Open Access Journals (Sweden)

    Sonia Fleury

    2009-06-01

    Full Text Available O artigo apresenta a trajetória das políticas sociais no Brasil e identifica, em cada etapa, o modelo de proteção social vigente. Afirma que a Constituição Federal de 1988, ao introduzir o conceito de Seguridade Social e criar o Sistema Único de Saúde, representou uma ruptura com o modelo tanto de Estado quanto de cidadania anteriores, em resposta à mobilização social que a antecedeu. A subordinação dos princípios de justiça e inclusão social, que orientaram o desenho desse novo padrão de proteção social, a uma política liberal e monetarista, tiveram importantes impactos na fase de implementação das políticas sociais. No entanto, os dilemas que atravessam tais políticas e, em particular, a construção do sistema único de saúde devem ser analisadas sob uma perspectiva teórica que compreende as convergências e divergências entre os três movimentos que caracterizaram a Reforma Sanitária brasileira, quais são: a subjetivação, a constitucionalização e a institucionalização.The article presents the trajectory of social policies in Brazil and identifies, at each stage, the existing social protection model. It affirms that the Federal Constitution of 1988, when it introduced the concept of Social Security and created the National Health Care System, represented a rupture with what came before. The subordination of the principles of justice and social inclusion, which guided the design of this new social protection model, to a liberal and monetarist policy had important impacts in the phase of implementation of the social policies. However, the dilemma that such policies go through and, in particular, the construction of the National Health Care System must be analyzed from a theoretical perspective that encompasses the agreements and disagreements between the three movements that characterize Brazilian Sanitary Reform, which are: subjectivation, constitutionalization and institutionalization.

  18. Aborto e eutanásia: dilemas contemporâneos sobre os limites da vida Abortion and euthanasia: contemporary issues on the limits of life

    Directory of Open Access Journals (Sweden)

    Edlaine de Campos Gomes

    2008-01-01

    Full Text Available Este artigo analisa a polêmica em torno da determinação dos limites da vida, a partir do pressuposto de que a demarcação das fronteiras entre vida e morte envolve questões culturais, sociais, religiosas e políticas referentes à gestão da pessoa. Debates acerca do aborto e da eutanásia evidenciam concepções morais sobre os direitos individuais que, por sua vez, são passíveis de normatização em cada contexto. Tais temas revelam para além da criação e do desenvolvimento de novas tecnologias médicas, direcionadas à reprodução assistida, medicina fetal e manutenção artificial da vida, seja de prematuros ou de doentes fora de possibilidades de cura valores e posicionamentos, muitas vezes contrastivos. A partir de levantamento de projetos de lei apresentados no âmbito legislativo brasileiro, constatou-se a presença de discursos opostos, oriundos da religião e de defensores da autonomia individual, o que ilustra os dilemas contemporâneos sobre os limites da vida.This article analyzes the controversy surrounding what can be established as the limit of life, from the presumption that the frontier marks between life and death involve cultural, social, religious and political issues referred to personhood management. Debates about abortion and euthanasia make it clear that moral concepts on individual rights can be standardized in each context. These themes reveal beyond new medical technology creation and development, focused on assisted fertilization, fetal medicine and maintaining life artificially, either for premature babies or patients without possibilities of cure values and viewpoints, often opposed. From the survey of law projects, presented within Brazilian legislative field, opposite positions were revealed, from religion and defenders of individual autonomy, which illustrates the contemporary dilemmas on the limits of life.

  19. Esporte Interativo e o Dilema de Distribuição de Conteúdo: Um Estudo de Caso para Ensino

    Directory of Open Access Journals (Sweden)

    Daniela Abrantes Ferreira

    2016-05-01

    Full Text Available Este caso de ensino descreve a trajetória do grupo de mídia brasileiro Esporte Interativo (EI, empresa iniciada por três jovens empreendedores e dedicada a produzir e distribuir conteúdo esportivo em múltiplas plataformas. O dilema está centrado no CEO e sócio-fundador do grupo, Edgar Diniz, que enfrenta um novo momento na empresa com a venda iminente para a Turner, braço televisivo do grupo americano Time Warner, no final de 2014. O choque de modelos de negócios podem representar desafios para a gestão da empresa, que precisa decidir os rumos estratégicos futuros. As informações utilizadas no caso são reais e foram obtidas através de entrevistas em profundidade, com roteiro semiestruturado, com o fundador e CEO da empresa, o outro fundador e Vice Presidente de Mídias Digitais e o Vice Presidente de Desenvolvimento de Negócios, além de investigação documental e revisão bibliográfica. Sugere-se que o caso seja utilizado para alunos de pós graduação, em disciplinas de Estratégia Empresarial, com os seguintes objetivos educacionais: a Análise de ecossistemas de negócios e reconfiguração de indústrias a partir das mudanças geradas pelo desenvolvimento das Tecnologias de Informação e Comunicação; b Compreensão das questões estratégicas relacionadas à gestão de plataformas e das dinâmicas “winner-takes-all”, onde as recompensas por se alcançar a liderança são desproporcionais à vantagem que se possui sobre quem não a alcança, típicas de mercados em rede; c Discussão dos tipos de inovação (incremental e disruptiva e suas consequências para novos entrantes e incumbentes; d Planejamento com Cenários.

  20. CO2 efflux from subterranean nests of ant communities in a seasonal tropical forest, Thailand

    OpenAIRE

    Hasin, Sasitorn; Ohashi, Mizue; Yamada, Akinori; Hashimoto, Yoshiaki; Tasen, Wattanachai; Kume, Tomonori; Yamane, Seiki

    2014-01-01

    Many ant species construct subterranean nests. The presence of their nests may explain soil respiration “hot spots”, an important factor in the high CO2 efflux from tropical forests. However, no studies have directly measured CO2 efflux from ant nests. We established 61 experimental plots containing 13 subterranean ant species to evaluate the CO2 efflux from subterranean ant nests in a tropical seasonal forest, Thailand. We examined differences in nest CO2 efflux among ant species. We determi...

  1. Using ant-behavior-based simulation model AntWeb to improve website organization

    Science.gov (United States)

    Li, Weigang; Pinheiro Dib, Marcos V.; Teles, Wesley M.; Morais de Andrade, Vlaudemir; Alves de Melo, Alba C. M.; Cariolano, Judas T.

    2002-03-01

    Some web usage mining algorithms showed the potential application to find the difference among the organizations expected by visitors to the website. However, there are still no efficient method and criterion for a web administrator to measure the performance of the modification. In this paper, we developed an AntWeb, a model inspired by ants' behavior to simulate the sequence of visiting the website, in order to measure the efficient of the web structure. We implemented a web usage mining algorithm using backtrack to the intranet website of the Politec Informatic Ltd., Brazil. We defined throughput (the number of visitors to reach their target pages per time unit relates to the total number of visitors) as an index to measure the website's performance. We also used the link in a web page to represent the effect of visitors' pheromone trails. For every modification in the website organization, for example, putting a link from the expected location to the target object, the simulation reported the value of throughput as a quick answer about this modification. The experiment showed the stability of our simulation model, and a positive modification to the intranet website of the Politec.

  2. Population Development of Several Species of Ants on the Cocoa Trees in South Sulawesi

    Directory of Open Access Journals (Sweden)

    Fatahuddin Fatahuddin

    2010-08-01

    Full Text Available Several species of ants with different behavior have been found in cocoa plantations and their behavior is important to be considered because it might be correlated with the degree of protection of cocoa plant from cocoa pests. The aim of this research is to manipulate and to develop ants population in environment, so they are able to establish permanently in cocoa trees. This research was conducted in Papakaju Regions Luwu Regency in Juli to November 2009. In this study, 10 cocoa trees with ants were sampled (each species of ant in 10 cocoa trees. A control of 10 tree samples without ant was also taken. In order to assess the abundance of ant population, it was grouped based on scoring, which score 1 for less than 20 ants, score 2 for 21–50 ants, score 3 for 51–200 ants, score 4 for 201–1000 ants, and score 5 for more than 1000 per tree. The results indicated that average of population score of the three ants species reached the highest population for the Oecophylla. smaragdina with average score 4.85 (>1000 ants, Dolichoderus thoracicus, with average score 3.90 (> 200 ants and Crematogaster. difformis with average score 3.10 (>200 ants. This research indicated that three species of ants, Oecophylla smaragdina (weaver ant, Dolichoderus thoracicus (cocoa black ant and Crematogaster difformis (cracking ant. in farmer cocoa plantations in South Sulawesi giving better performance against major pests of cocoa in particular cocoa pod borer (CPB. Key words: Ant Population, Oecophylla smaragdina, Dolichoderus thoracicus, Crematogaster difformis, artificial nest, cocoa.

  3. Valoración y necesidades formativas percibidas tras el período de prácticas en la formación inicial de maestros

    Directory of Open Access Journals (Sweden)

    Isabel RIDAO GARCÍA

    2009-11-01

    Full Text Available RESUMEN: En este trabajo exploramos, por medio de un cuestionario de preguntas abiertas, las opiniones de los alumnos de Magisterio acerca de las prácticas realizadas dentro de su programa de formación inicial y las necesidades formativas que perciben de cara a un nuevo periodo de prácticas. Los resultados apuntan hacia una valoración positiva, en tanto que las prácticas permiten un primer contacto con la realidad escolar y con los niños, destacando como problemas la falta de orientación, la dificultad para afrontar aspectos concretos (disciplina, motivación, atención a la diversidad, innovación, etc. y ciertas disfunciones organizativas. Las necesidades de formación expresadas por los alumnos definen un abanico de conocimientos y habilidades que consideran necesarios antes de volver a la experiencia práctica, y sugieren medidas de mejora en el actual modelo organizativo.ABSTRACT: This study deals with the teachers initial training programmes at Teachers University Colleges. Students' opinions are assessed by means of an openended questionnaire about the initial training programme and their training needs for further practical stages. Results show a positive consideration for the practical stages because of their enabling students to get in contact with the actual school reality and pupils. Lack of orientation and difficulties to face specific problems (discipline, motivation, attention to diversity, innovation... As well as organization mismatches at the initial training program, were mentioned as some of the problems. Training needs reported identify a set of knowledges and skills that students consider necessary to be mastered for facing practical stages ahead. Similarly, students' opnions suggest innovations for the present organization model.RESUME: Dans ce travail, nous posons des questions ouvertes pour recueillir les opinions des élèves de l'École de Formation des Professeurs sur les périodes de formation pratique qu

  4. O cuidado medicamentoso à criança com HIV: desafios e dilemas de familiares cuidadores El cuidado medicamentoso al niño con VIH: desafíos y dilemas de familiares cuidadores The medication care to children with HIV: challenges and dilemmas of family caregivers

    Directory of Open Access Journals (Sweden)

    Antonio Marcos Tosoli Gomes

    2009-04-01

    Full Text Available O cuidado medicamentoso a criança HIV/Aids é marcado por desafios e dilemas. Neste contexto, objetiva-se discutir as situações existenciais vivenciadas por cuidadores na implementação desse cuidado. Trata-se de um estudo qualitativo desenvolvido segundo o Método Criativo e Sensível com 13 cuidadores atendidos em um ambulatório. Os dados foram coletados pela dinâmica do concreto e analisados pela análise de discurso. Percebe-se um processo de normalização dos medicamentos e destaca-se a não utilização de recursos lúdicos para a sua administração. Observa-se que o início do uso é dificultado pelos efeitos colaterais e que posteriormente surgem questionamentos quanto à necessidade do uso. Conclui-se que o cuidado é permeado por preconceitos e estigmas e ressalta-se a importância do profissional enfermeiro como educador em saúde.El cuidado medicamentoso al niño HIV/ SIDA está marcado por desafíos y dilemas. En este contexto, se objeta discutir las situaciones existenciales vivenciadas por cuidadores en la implementación de este cuidado. Se trata de un estudio cualitativo desarrollado según el Método Creativo y Sensible con 13 cuidadores atendidos en ambulatorio. Los datos fueron recogidos por la dinámica del concreto y analizados por el análisis del discurso. Se percibe un proceso de normalización de los medicamentos y se destaca la no utilización de recursos lúdicos para su administración. Se observa que el inicio del uso está dificultado por los efectos colaterales y que posteriormente surgen cuestionamientos en cuanto a la necesidad del uso. Se concluye que el cuidado está afectado por prejuicios y estigmas y se destaca la importancia del profesional enfermero como educador de la salud.The medication care to children with HIV/Aids is marked with challenges and dilemmas. In this context, the purpose of this study is to discuss on the existential situations lived by caregivers when administering that care

  5. Graveyards on the Move: The Spatio-Temporal Distribution of Dead Ophiocordyceps-Infected Ants

    DEFF Research Database (Denmark)

    Pontoppidan, Maj-Britt; Himaman, Winanda; Hywel-Jones, Nigel L.

    2009-01-01

    rainforest. We established that high density aggregations exist (up to 26 dead ants/m2), which we coined graveyards. We further established that graveyards are patchily distributed in a landscape with no or very few O. unilateralis-killed ants. At some, but not all, spatial scales of analysis the density...... unilateralis, which is pan-tropical in distribution, causes infected worker ants to leave their nest and die under leaves in the understory of tropical rainforests. Working in a forest dynamic plot in Southern Thailand we mapped the occurrence of these dead ants by examining every leaf in 1,360 m2 of primary...... of dead ants correlated with temperature, humidity and vegetation cover. Remarkably, having found 2243 dead ants inside graveyards we only found 2 live ants of the principal host, ant Camponotus leonardi, suggesting that foraging host ants actively avoid graveyards. We discovered that the principal host...

  6. Various chemical strategies to deceive ants in three Arhopala species (lepidoptera: Lycaenidae exploiting Macaranga myrmecophytes.

    Directory of Open Access Journals (Sweden)

    Yoko Inui

    Full Text Available Macaranga myrmecophytes (ant-plants are generally well protected from herbivore attacks by their symbiotic ants (plant-ants. However, larvae of Arhopala (Lepidoptera: Lycaenidae species survive and develop on specific Macaranga ant-plant species without being attacked by the plant-ants of their host species. We hypothesized that Arhopala larvae chemically mimic or camouflage themselves with the ants on their host plant so that the larvae are accepted by the plant-ant species of their host. Chemical analyses of cuticular hydrocarbons showed that chemical congruency varied among Arhopala species; A. dajagaka matched well the host plant-ants, A. amphimuta did not match, and unexpectedly, A. zylda lacked hydrocarbons. Behaviorally, the larvae and dummies coated with cuticular chemicals of A. dajagaka were well attended by the plant-ants, especially by those of the host. A. amphimuta was often attacked by all plant-ants except for the host plant-ants toward the larvae, and those of A. zylda were ignored by all plant-ants. Our results suggested that conspicuous variations exist in the chemical strategies used by the myrmecophilous butterflies that allow them to avoid ant attack and be accepted by the plant-ant colonies.

  7. Neuromodulation of Nestmate Recognition Decisions by Pavement Ants.

    Directory of Open Access Journals (Sweden)

    Andrew N Bubak

    Full Text Available Ant colonies are distributed systems that are regulated in a non-hierarchical manner. Without a central authority, individuals inform their decisions by comparing information in local cues to a set of inherent behavioral rules. Individual behavioral decisions collectively change colony behavior and lead to self-organization capable of solving complex problems such as the decision to engage in aggressive societal conflicts with neighbors. Despite the relevance to colony fitness, the mechanisms that drive individual decisions leading to cooperative behavior are not well understood. Here we show how sensory information, both tactile and chemical, and social context-isolation, nestmate interaction, or fighting non-nestmates-affects brain monoamine levels in pavement ants (Tetramorium caespitum. Our results provide evidence that changes in octopamine and serotonin in the brains of individuals are sufficient to alter the decision by pavement ants to be aggressive towards non-nestmate ants whereas increased brain levels of dopamine correlate to physical fighting. We propose a model in which the changes in brain states of many workers collectively lead to the self-organization of societal aggression between neighboring colonies of pavement ants.

  8. Neuromodulation of Nestmate Recognition Decisions by Pavement Ants.

    Science.gov (United States)

    Bubak, Andrew N; Yaeger, Jazmine D W; Renner, Kenneth J; Swallow, John G; Greene, Michael J

    2016-01-01

    Ant colonies are distributed systems that are regulated in a non-hierarchical manner. Without a central authority, individuals inform their decisions by comparing information in local cues to a set of inherent behavioral rules. Individual behavioral decisions collectively change colony behavior and lead to self-organization capable of solving complex problems such as the decision to engage in aggressive societal conflicts with neighbors. Despite the relevance to colony fitness, the mechanisms that drive individual decisions leading to cooperative behavior are not well understood. Here we show how sensory information, both tactile and chemical, and social context-isolation, nestmate interaction, or fighting non-nestmates-affects brain monoamine levels in pavement ants (Tetramorium caespitum). Our results provide evidence that changes in octopamine and serotonin in the brains of individuals are sufficient to alter the decision by pavement ants to be aggressive towards non-nestmate ants whereas increased brain levels of dopamine correlate to physical fighting. We propose a model in which the changes in brain states of many workers collectively lead to the self-organization of societal aggression between neighboring colonies of pavement ants.

  9. Ants avoid superinfections by performing risk-adjusted sanitary care.

    Science.gov (United States)

    Konrad, Matthias; Pull, Christopher D; Metzler, Sina; Seif, Katharina; Naderlinger, Elisabeth; Grasse, Anna V; Cremer, Sylvia

    2018-03-13

    Being cared for when sick is a benefit of sociality that can reduce disease and improve survival of group members. However, individuals providing care risk contracting infectious diseases themselves. If they contract a low pathogen dose, they may develop low-level infections that do not cause disease but still affect host immunity by either decreasing or increasing the host's vulnerability to subsequent infections. Caring for contagious individuals can thus significantly alter the future disease susceptibility of caregivers. Using ants and their fungal pathogens as a model system, we tested if the altered disease susceptibility of experienced caregivers, in turn, affects their expression of sanitary care behavior. We found that low-level infections contracted during sanitary care had protective or neutral effects on secondary exposure to the same (homologous) pathogen but consistently caused high mortality on superinfection with a different (heterologous) pathogen. In response to this risk, the ants selectively adjusted the expression of their sanitary care. Specifically, the ants performed less grooming and more antimicrobial disinfection when caring for nestmates contaminated with heterologous pathogens compared with homologous ones. By modulating the components of sanitary care in this way the ants acquired less infectious particles of the heterologous pathogens, resulting in reduced superinfection. The performance of risk-adjusted sanitary care reveals the remarkable capacity of ants to react to changes in their disease susceptibility, according to their own infection history and to flexibly adjust collective care to individual risk.

  10. PARAMETER ESTIMATION OF VALVE STICTION USING ANT COLONY OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    S. Kalaivani

    2012-07-01

    Full Text Available In this paper, a procedure for quantifying valve stiction in control loops based on ant colony optimization has been proposed. Pneumatic control valves are widely used in the process industry. The control valve contains non-linearities such as stiction, backlash, and deadband that in turn cause oscillations in the process output. Stiction is one of the long-standing problems and it is the most severe problem in the control valves. Thus the measurement data from an oscillating control loop can be used as a possible diagnostic signal to provide an estimate of the stiction magnitude. Quantification of control valve stiction is still a challenging issue. Prior to doing stiction detection and quantification, it is necessary to choose a suitable model structure to describe control-valve stiction. To understand the stiction phenomenon, the Stenman model is used. Ant Colony Optimization (ACO, an intelligent swarm algorithm, proves effective in various fields. The ACO algorithm is inspired from the natural trail following behaviour of ants. The parameters of the Stenman model are estimated using ant colony optimization, from the input-output data by minimizing the error between the actual stiction model output and the simulated stiction model output. Using ant colony optimization, Stenman model with known nonlinear structure and unknown parameters can be estimated.

  11. New fossil ants in French Cretaceous amber (Hymenoptera: Formicidae)

    Science.gov (United States)

    Perrichot, Vincent; Nel, André; Néraudeau, Didier; Lacau, Sébastien; Guyot, Thierry

    2008-02-01

    Recent studies on the ant phylogeny are mainly based on the molecular analyses of extant subfamilies and do not include the extinct, only Cretaceous subfamily Sphecomyrminae. However, the latter is of major importance for ant relationships, as it is considered the most basal subfamily. Therefore, each new discovery of a Mesozoic ant is of high interest for improving our understanding of their early history and basal relationships. In this paper, a new sphecomyrmine ant, allied to the Burmese amber genus Haidomyrmex, is described from mid-Cretaceous amber of France as Haidomyrmodes mammuthus gen. and sp. n. The diagnosis of the tribe Haidomyrmecini is emended based on the new type material, which includes a gyne (alate female) and two incomplete workers. The genus Sphecomyrmodes, hitherto known by a single species from Burmese amber, is also reported and a new species described as S. occidentalis sp. n. after two workers remarkably preserved in a single piece of Early Cenomanian French amber. The new fossils provide additional information on early ant diversity and relationships and demonstrate that the monophyly of the Sphecomyrminae, as currently defined, is still weakly supported.

  12. The cavity-nest ant Temnothorax crassispinus prefers larger nests.

    Science.gov (United States)

    Mitrus, S

    Colonies of the ant Temnothorax crassispinus inhabit mostly cavities in wood and hollow acorns. Typically in the field, nest sites that can be used by the ant are a limited resource. In a field experiment, it was investigated whether the ants prefer a specific size of nest, when different ones are available. In July 2011, a total of 160 artificial nests were placed in a beech-pine forest. Four artificial nests (pieces of wood with volume cavities, ca 415, 605, 730, and 980 mm 3 , respectively) were located on each square meter of the experimental plot. One year later, shortly before the emergence of new sexuals, the nests were collected. In July 2012, colonies inhabited more frequently bigger nests. Among queenright colonies, the ones which inhabited bigger nests had more workers. However, there was no relationship between volume of nest and number of workers for queenless colonies. Queenright colonies from bigger nests produced more sexual individuals, but there was no correlation between number of workers and sex allocation ratio, or between volume of nest and sex allocation ratio. In a laboratory experiment where ant colonies were kept in 470 and 860 mm 3 nests, larger colonies allocated more energy to produce sexual individuals. The results of this study show the selectivity of T. crassispinus ants regarding the size of nest cavity, and that the nest volume has an impact on life history parameters.

  13. Polarized light use in the nocturnal bull ant, Myrmecia midas.

    Science.gov (United States)

    Freas, Cody A; Narendra, Ajay; Lemesle, Corentin; Cheng, Ken

    2017-08-01

    Solitary foraging ants have a navigational toolkit, which includes the use of both terrestrial and celestial visual cues, allowing individuals to successfully pilot between food sources and their nest. One such celestial cue is the polarization pattern in the overhead sky. Here, we explore the use of polarized light during outbound and inbound journeys and with different home vectors in the nocturnal bull ant, Myrmecia midas . We tested foragers on both portions of the foraging trip by rotating the overhead polarization pattern by ±45°. Both outbound and inbound foragers responded to the polarized light change, but the extent to which they responded to the rotation varied. Outbound ants, both close to and further from the nest, compensated for the change in the overhead e-vector by about half of the manipulation, suggesting that outbound ants choose a compromise heading between the celestial and terrestrial compass cues. However, ants returning home compensated for the change in the e-vector by about half of the manipulation when the remaining home vector was short (1-2 m) and by more than half of the manipulation when the remaining vector was long (more than 4 m). We report these findings and discuss why weighting on polarization cues change in different contexts.

  14. Stigmergic construction and topochemical information shape ant nest architecture.

    Science.gov (United States)

    Khuong, Anaïs; Gautrais, Jacques; Perna, Andrea; Sbaï, Chaker; Combe, Maud; Kuntz, Pascale; Jost, Christian; Theraulaz, Guy

    2016-02-02

    The nests of social insects are not only impressive because of their sheer complexity but also because they are built from individuals whose work is not centrally coordinated. A key question is how groups of insects coordinate their building actions. Here, we use a combination of experimental and modeling approaches to investigate nest construction in the ant Lasius niger. We quantify the construction dynamics and the 3D structures built by ants. Then, we characterize individual behaviors and the interactions of ants with the structures they build. We show that two main interactions are involved in the coordination of building actions: (i) a stigmergic-based interaction that controls the amplification of depositions at some locations and is attributable to a pheromone added by ants to the building material; and (ii) a template-based interaction in which ants use their body size as a cue to control the height at which they start to build a roof from existing pillars. We then develop a 3D stochastic model based on these individual behaviors to analyze the effect of pheromone presence and strength on construction dynamics. We show that the model can quantitatively reproduce key features of construction dynamics, including a large-scale pattern of regularly spaced pillars, the formation and merging of caps over the pillars, and the remodeling of built structures. Finally, our model suggests that the lifetime of the pheromone is a highly influential parameter that controls the growth and form of nest architecture.

  15. DATA MINING UNTUK KLASIFIKASI PELANGGAN DENGAN ANT COLONY OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    Maulani Kapiudin

    2007-01-01

    Full Text Available In this research the system for potentially customer classification is designed by extracting rule based classification from raw data with certain criteria. The searching process uses customer database from a bank with data mining technic by using ant colony optimization. A test based on min_case_per_rule variety and phenomene updating were done on a certain period of time. The result are group of customer class which base on rules built by ant and by modifying the pheromone updating, the area of the case is getting bigger. Prototype of the software is coded with C++ 6 version. The customer database master is created by using Microsoft Access. This paper gives information about potential customer of bank that can be classified by prototype of the software. Abstract in Bahasa Indonesia : Pada penelitian untuk sistem klasifikasi potensial customer ini didesain dengan melakukan ekstrak rule berdasarkan klasifikasi dari data mentah dengan kriteria tertentu. Proses pencarian menggunakan database pelanggan dari suatu bank dengan teknik data mining dengan ant colony optimization. Dilakukan percobaan dengan min_case_per_rule variety dan phenomene updating pada periode waktu tertentu. Hasilnya adalah sekelompok class pelanggan yang didasarkan dari rules yang dibangun dengan ant dan dengan dimodifikasi dengan pheromone updating, area permasalahan menjadi lebih melebar. Prototype dari software ini menggunakan C++ versi 6. Database pelanggan dibangun dengan Microsoft Access. Paper ini memberikan informasi mengenai potensi pelanggan dari bank, sehingga dapat diklasifikasikan dengan prototype dari software. Kata kunci: ant colony optimization, classification, min_case_per_rule, term, pheromone updating

  16. Normas percibidas por estudiantes peruanos acerca de sus pares y el uso de drogas Normas percebidas por estudantes peruanos sobre uso de drogas entre seus pares Perceived norms among peruvian students for drug use among peers

    Directory of Open Access Journals (Sweden)

    Inés V. Bustamante

    2009-01-01

    Full Text Available El objetivo de este estudio fue estimar la diferencia entre las normas percibidas sobre el uso de drogas por sus pares y el uso real de drogas entre universitarios, entre 18 y 24 años, de las áreas de salud. Se trata de un estudio transversal, basado en un censo y en un cuestionario anónimo y autoaplicado. Participaron 306 estudiantes (82%. La proporción del consumo, en el último año, fue de 51,3% para el tabaco, 90,8% para el alcohol, 5,9% para la marihuana y 0,7% para la cocaína. Se observó una diferencia entre la norma percibida de consumo y la proporción de uso real informado para el tabaco (70% vs. 51.3%, marihuana (10% vs. 5.9% y cocaína (8.3% vs. 0.7%. Se concluye que los universitarios sobrestiman el consumo de tabaco, marihuana y cocaína de sus pares.O objetivo deste estudo foi avaliar a diferença entre as normas percebidas pelos estudantes universitários, com idade entre 18 e 24 anos, sobre o uso de drogas pelos seus pares e o uso de drogas relatado pelos próprios estudantes em cursos da área da saúde. Foi usado o método transversal, baseado em censo realizado através de questionário, preenchido pelos próprios estudantes, sem identificação. O número de participantes foi de 306 (82%. Como resultados obteve-se: a proporção de estudantes que utilizou drogas no último ano foi de 51,3% para o tabaco, 90,8% para o álcool, 5,9% para a maconha e 0,7% para a cocaína. Diferença entre as normas percebidas e o uso de drogas foi observada para o tabaco (70% vs 51,3%, maconha (10% vs 5.9% e cocaína (8,3% vs 0,7%. Conclui-se que os estudantes universitários apresentaram estimativa aumentada sobre o consumo de tabaco, maconha e cocaína entre seus pares.Objective: to evaluate the difference between perceived norms about drug use among peer and actual drug use as reported by the same university students. The students were between 18 and 24 years old and attended health courses. Method: cross-sectional study based on a

  17. Channeler Ant Model: 3 D segmentation of medical images through ant colonies

    International Nuclear Information System (INIS)

    Fiorina, E.; Valzano, S.; Arteche Diaz, R.; Bosco, P.; Gargano, G.; Megna, R.; Oppedisano, C.; Massafra, A.

    2011-01-01

    In this paper the Channeler Ant Model (CAM) and some results of its application to the analysis of medical images are described. The CAM is an algorithm able to segment 3 D structures with different shapes, intensity and background. It makes use of virtual and colonies and exploits their natural capabilities to modify the environment and communicate with each other by pheromone deposition. Its performance has been validated with the segmentation of 3 D artificial objects and it has been already used successfully in lung nodules detection on Computer Tomography images. This work tries to evaluate the CAM as a candidate to solve the quantitative segmentation problem in Magnetic Resonance brain images: to evaluate the percentage of white matter, gray matter and cerebrospinal fluid in each voxel.

  18. Sensación térmica percibida en vivienda económica y auto-producida, en periodo cálido, para clima cálido húmedo

    Directory of Open Access Journals (Sweden)

    Carmen Garcia Gomez

    Full Text Available El estudio de la sensación térmica percibida en la vivienda, permite establecer lineamientos de diseño para la habitabilidad térmica, con base en la percepción de los sujetos. En trabajos anteriores, se plantea que la adaptación de las personas en climas cálidos, está definida por preferencias según el estrato socioeconómico y cultural, basado en su tipología de vivienda. Se presenta la comparación entre dos investigaciones sobre confort térmico desarrolladas en Mérida, Yucatán, México, con clima cálido húmedo. Los sujetos de estudio fueron habitantes de vivienda de tipo económico y auto-producida. Se utilizó el enfoque de adaptación, se trabajó con base en la norma ISO 10551 (1995 y se registraron temperatura de bulbo seco, temperatura de globo negro, humedad relativa y velocidad de viento. Se estimó la temperatura neutral con el método de medias por intervalo de sensación térmica, y se compararon preferencia, aceptación y tolerancia del ambiente térmico. Los resultados de ambas investigaciones muestran variaciones en la temperatura neutral y rangos de confort térmico, además se presentan diferencias significativas en el nivel de adaptación, experiencia y expectativa, aún cuando las condiciones del ambiente térmico presentan similitudes.

  19. La evaluación de la calidad percibida del servicio como elemento clave para la gestión de los clubs de golf en España

    Directory of Open Access Journals (Sweden)

    Virginia Serrano Gómez

    2010-12-01

    Full Text Available El objetivo del estudio es llevar a cabo una aproximación empírica, orientada a la gestión, a la modelización y medida de la calidad percibida del servicio prestado en los clubes de golf españoles, teniendo como fin último el de elaborar y perfeccionar herramientas que resulten útiles a nivel aplicado para poder identificar los puntos débiles de su servicio y la definición de mejora, encaminadas a incrementar la satisfacción final y el mantenimiento de sus socios. Para la recogida de la información, se recurrió a una entrevista personal y a la utilización de un cuestionario elaborado ad hoc, para ser utilizado entre los socios de un club de golf situado en A Coruña. Los resultados del análisis factorial indican que hay 5 grandes dimensiones: Personal, Condiciones Físicas, Organización y Gestión, Instalaciones y Servicios Complementarios, y Vestuarios y Taquillas. No obstante, el análisis de regresión lineal realizado permite señalar dos de ellas (Organización y Gestión y Condiciones Físicas, como aquellas dimensiones que tienen un peso mayor sobre la satisfacción global del cliente, lo que se traduce en información de gran interés estratégico para el club.

  20. Regulation and specificity of antifungal metapleural gland secretion in leaf-cutting ants

    DEFF Research Database (Denmark)

    Yek, Sze Huei; Nash, David Richard; Jensen, Annette Bruun

    2012-01-01

    significantly larger for ants challenged with virulent and mild pathogens/weeds than for controls and Escovopsis-challenged ants. We conclude that the MG defence system of leaf-cutting ants has characteristics reminiscent of an additional cuticular immune system, with specific and non-specific components......Ants have paired metapleural glands (MGs) to produce secretions for prophylactic hygiene. These exocrine glands are particularly well developed in leaf-cutting ants, but whether the ants can actively regulate MG secretion is unknown. In a set of controlled experiments using conidia of five fungi...

  1. Application of chaotic ant swarm optimization in electric load forecasting

    International Nuclear Information System (INIS)

    Hong, W.-C.

    2010-01-01

    Support vector regression (SVR) had revealed strong potential in accurate electric load forecasting, particularly by employing effective evolutionary algorithms to determine suitable values of its three parameters. Based on previous research results, however, these employed evolutionary algorithms themselves have several drawbacks, such as converging prematurely, reaching slowly the global optimal solution, and trapping into a local optimum. This investigation presents an SVR-based electric load forecasting model that applied a novel algorithm, namely chaotic ant swarm optimization (CAS), to improve the forecasting performance by searching its suitable parameters combination. The proposed CAS combines with the chaotic behavior of single ant and self-organization behavior of ant colony in the foraging process to overcome premature local optimum. The empirical results indicate that the SVR model with CAS (SVRCAS) results in better forecasting performance than the other alternative methods, namely SVRCPSO (SVR with chaotic PSO), SVRCGA (SVR with chaotic GA), regression model, and ANN model.

  2. Social isolation and brain development in the ant Camponotus floridanus.

    Science.gov (United States)

    Seid, Marc A; Junge, Erich

    2016-06-01

    Social interactions play a key role in the healthy development of social animals and are most pronounced in species with complex social networks. When developing offspring do not receive proper social interaction, they show developmental impairments. This effect is well documented in mammalian species but controversial in social insects. It has been hypothesized that the enlargement of the mushroom bodies, responsible for learning and memory, observed in social insects is needed for maintaining the large social networks and/or task allocation. This study examines the impact of social isolation on the development of mushroom bodies of the ant Camponotus floridanus. Ants raised in isolation were shown to exhibit impairment in the growth of the mushroom bodies as well as behavioral differences when compared to ants raised in social groups. These results indicate that social interaction is necessary for the proper development of C. floridanus mushroom bodies.

  3. Antígonas. Una visión intertextual

    Directory of Open Access Journals (Sweden)

    Elena Cano Turrión

    2011-04-01

    Full Text Available In this article and from an intertextual point of view, we will try to examine how theSophoclean hypotext has generated three very different hypertexts. The first one is the short story“Antígona o la elección” by M. Yourcenar, which goes further the religious motivation in the originaltext; then, there is an essay written as a dialogue by Maria Zambrano, entitled La tumba de Antígonawhich main topics are confrontation against power, lack of freedom and destiny and faith in humanconscience. Finally, Luis Riaza’s Antígona…¡Cerda! Appears closer to its hypotext but at the same timesemantic deviation becomes more relevant.

  4. Effective ANT based Routing Algorithm for Data Replication in MANETs

    Directory of Open Access Journals (Sweden)

    N.J. Nithya Nandhini

    2013-12-01

    Full Text Available In mobile ad hoc network, the nodes often move and keep on change its topology. Data packets can be forwarded from one node to another on demand. To increase the data accessibility data are replicated at nodes and made as sharable to other nodes. Assuming that all mobile host cooperative to share their memory and allow forwarding the data packets. But in reality, all nodes do not share the resources for the benefits of others. These nodes may act selfishly to share memory and to forward the data packets. This paper focuses on selfishness of mobile nodes in replica allocation and routing protocol based on Ant colony algorithm to improve the efficiency. The Ant colony algorithm is used to reduce the overhead in the mobile network, so that it is more efficient to access the data than with other routing protocols. This result shows the efficiency of ant based routing algorithm in the replication allocation.

  5. Mating, hybridisation and introgression in Lasius ants (Hymenoptera: Formicidae)

    DEFF Research Database (Denmark)

    Van der Have, Tom; Pedersen, Jes Søe; Boomsma, Jacobus Jan

    2011-01-01

    Recent reviews have shown that hybridisation among ant species is likely to be more common than previously appreci-ated, but that documented cases of introgression remain rare. After molecular phylogenetic work had shown that Euro-pean Lasius niger (LINNAEUS, 1758) and L. psammophilus SEIFERT, 1992...... (formerly L. alienus (FOERSTER, 1850)) are unlikely to be very closely related, we decided to analyse an old data set confirming the conclusion by PEARSON (1983) that these two ants can indeed form viable hybrids. We show that signatures of introgression can be detected in a Danish site...... sympatrically. This would imply that multiple accessible field sites are available to study the molecular details of hybridisation and in-trogression between two ant species that have variable degrees of sympatry throughout their distributional ranges...

  6. Evolutionary patterns of proteinase activity in attine ant fungus gardens

    DEFF Research Database (Denmark)

    Semenova, Tatyana; Hughes, David Peter; Boomsma, Jacobus Jan

    2011-01-01

    hypothesized that fungal proteinase activity may have been under selection for efficiency and that different classes of proteinases might be involved. Results: We determined proteinase activity profiles across a wide pH range for fungus gardens of 14 Panamanian species of fungus-growing ants, representing...... classes. Remarkably, the single symbiont that is shared by species of the crown group of Atta and Acromyrmex leaf-cutting ants mostly showed metalloproteinase activity, suggesting that recurrent changes in enzyme production may have occurred throughout the domestication history of fungus-garden symbionts......Background: Attine ants live in symbiosis with a basidiomycetous fungus that they rear on a substrate of plant material. This indirect herbivory implies that the symbiosis is likely to be nitrogen deprived, so that specific mechanisms may have evolved to enhance protein availability. We therefore...

  7. Comparative Immature Morphology of Brazilian Fire Ants (Hymenoptera: Formicidae: Solenopsis

    Directory of Open Access Journals (Sweden)

    Eduardo Gonçalves Paterson Fox

    2012-01-01

    Full Text Available Although common in Brazil, the biology of the fire ant Solenopsis saevissima (Smith is still poorly studied. Larval descriptions are useful to genus-level ant systematics and sometimes to species-level taxonomy. This study presents a detailed description of juveniles of S. saevissima from Brazil, which were compared with Brazilian specimens of Solenopsis invicta Buren, Solenopsis geminata (Fabricius, and Solenopsis altipunctata Pitts. Different larval instars were separated by diagnostic morphological traits which were confirmed by observing moults. Reproductive larvae could be easily sorted by their distinctive body dimensions and shape. Contrary to previous reports on this species, the larvae of S. saevissima proved to be generally identical to those of S. invicta, while a few specimens resembled those of other close species, such as Solenopsis megergates Trager. Mature larvae thus presented considerable intraspecific variation in some characters recently proposed to aid fire ant species separation (morphology of head hairs.

  8. Social context predicts recognition systems in ant queens

    DEFF Research Database (Denmark)

    Dreier, Stéphanie Agnès Jeanine; d'Ettorre, Patrizia

    2009-01-01

    Recognition of group-members is a key feature of sociality. Ants use chemical communication to discriminate nestmates from intruders, enhancing kin cooperation and preventing parasitism. The recognition code is embedded in their cuticular chemical profile, which typically varies between colonies....... We predicted that ants might be capable of accurate recognition in unusual situations when few individuals interact repeatedly, as new colonies started by two to three queens. Individual recognition would be favoured by selection when queens establish dominance hierarchies, because repeated fights...... for dominance are costly; but it would not evolve in absence of hierarchies. We previously showed that Pachycondyla co-founding queens, which form dominance hierarchies, have accurate individual recognition based on chemical cues. Here, we used the ant Lasius niger to test the null hypothesis that individual...

  9. Natural selection drives the evolution of ant life cycles.

    Science.gov (United States)

    Wilson, Edward O; Nowak, Martin A

    2014-09-02

    The genetic origin of advanced social organization has long been one of the outstanding problems of evolutionary biology. Here we present an analysis of the major steps in ant evolution, based for the first time, to our knowledge, on combined recent advances in paleontology, phylogeny, and the study of contemporary life histories. We provide evidence of the causal forces of natural selection shaping several key phenomena: (i) the relative lateness and rarity in geological time of the emergence of eusociality in ants and other animal phylads; (ii) the prevalence of monogamy at the time of evolutionary origin; and (iii) the female-biased sex allocation observed in many ant species. We argue that a clear understanding of the evolution of social insects can emerge if, in addition to relatedness-based arguments, we take into account key factors of natural history and study how natural selection acts on alleles that modify social behavior.

  10. Native supercolonies of unrelated individuals in the invasive Argentine ant

    DEFF Research Database (Denmark)

    Pedersen, Jes Søe; Krieger, Michael J. B.; Vogel, Valérie

    2006-01-01

    organization is not only a key attribute responsible for the ecological dominance of these ants, but also an evolutionary paradox because relatedness between nestmates is effectively zero. Recently, it has been proposed that, in the Argentine ant, unicoloniality is a derived trait that evolved after its......Kinship among group members has long been recognized as a main factor promoting the evolution of sociality and reproductive altruism, yet some ants have an extraordinary social organization, called unicoloniality, whereby individuals mix freely among physically separated nests. This type of social...... with related individuals who are aggressive toward members of other colonies, we found that native populations also form supercolonies, and are effectively unicolonial. Moreover, just as in introduced populations, the relatedness between nestmates is not distinguishable from zero in these native range...

  11. Ants at Ton Nga Chang Wildlife Sanctuary, Songkhla

    Directory of Open Access Journals (Sweden)

    Watanasit, S.

    2005-03-01

    Full Text Available The aim of this study was to investigate diversity of ant at Ton Nga Chang Wildlife Sanctuary, Hat Yai, Songkhla. Three line transects (100 m each were randomly set up in 2 types of forest area, disturbed and undisturbed. Hand collecting (HC and leaf litter sampling (LL were applied for ant collection within a time limit of 30 minutes for each method. This study was carried out every month during Febuary 2002- Febuary 2003. The results showed that 206 species were placed under 8 subfamilies: Aenictinae, Cerapachyinae, Dolichoderinae, Formicinae, Leptanillinae, Myrmicinae, Ponerinae and Pseudomyrmecinae. Study sites and collection methods could divide ant species into 2 groups, whereas seasonal change could not distinguish the groups by DCA of multivariate analysis.

  12. Social isolation and brain development in the ant Camponotus floridanus

    Science.gov (United States)

    Seid, Marc A.; Junge, Erich

    2016-06-01

    Social interactions play a key role in the healthy development of social animals and are most pronounced in species with complex social networks. When developing offspring do not receive proper social interaction, they show developmental impairments. This effect is well documented in mammalian species but controversial in social insects. It has been hypothesized that the enlargement of the mushroom bodies, responsible for learning and memory, observed in social insects is needed for maintaining the large social networks and/or task allocation. This study examines the impact of social isolation on the development of mushroom bodies of the ant Camponotus floridanus. Ants raised in isolation were shown to exhibit impairment in the growth of the mushroom bodies as well as behavioral differences when compared to ants raised in social groups. These results indicate that social interaction is necessary for the proper development of C. floridanus mushroom bodies.

  13. Ant colonies prefer infected over uninfected nest sites

    DEFF Research Database (Denmark)

    Pontieri, Luigi; Vojvodic, Svjetlana; Graham, Riley

    2014-01-01

    with sporulating mycelium of the entomopathogenic fungus Metarhizium brunneum (infected nests), nests containing nestmates killed by freezing (uninfected nests), and empty nests. In contrast to the expectation pharaoh ant colonies preferentially (84%) moved into the infected nest when presented with the choice...... the high risk of epidemics in group-living animals. Choosing nest sites free of pathogens is hypothesized to be highly efficient in invasive ants as each of their introduced populations is often an open network of nests exchanging individuals (unicolonial) with frequent relocation into new nest sites...... and low genetic diversity, likely making these species particularly vulnerable to parasites and diseases. We investigated the nest site preference of the invasive pharaoh ant, Monomorium pharaonis, through binary choice tests between three nest types: nests containing dead nestmates overgrown...

  14. EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

    DEFF Research Database (Denmark)

    De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G

    2010-01-01

    an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

  15. Pericarpial nectary-visiting ants do not provide fruit protection against pre-dispersal seed predators regardless of ant species composition and resource availability.

    Directory of Open Access Journals (Sweden)

    Priscila Andre Sanz-Veiga

    Full Text Available Extrafloral nectaries can occur in both vegetative and reproductive plant structures. In many Rubiaceae species in the Brazilian Cerrado, after corolla abscission, the floral nectary continues to secret nectar throughout fruit development originating post-floral pericarpial nectaries which commonly attract many ant species. The occurrence of such nectar secreting structures might be strategic for fruit protection against seed predators, as plants are expected to invest higher on more valuable and vulnerable parts. Here, we performed ant exclusion experiments to investigate whether the interaction with ants mediated by the pericarpial nectaries of Tocoyena formosa affects plant reproductive success by reducing the number of pre-dispersal seed predators. We also assessed whether ant protection was dependent on ant species composition and resource availability. Although most of the plants were visited by large and aggressive ant species, such as Ectatomma tuberculatum and species of the genus Camponotus, ants did not protect fruits against seed predators. Furthermore, the result of the interaction was neither related to ant species composition nor to the availability of resources. We suggest that these results may be related to the nature and behavior of the most important seed predators, like Hemicolpus abdominalis weevil which the exoskeleton toughness prevent it from being predated by most ant species. On the other hand, not explored factors, such as reward quality, local ant abundance, ant colony characteristics and/or the presence of alternative energetic sources could also account for variations in ant frequency, composition, and finally ant protective effects, highlighting the conditionality of facultative plant-ant mutualisms.

  16. Reflexões, dilemas e responsabilidades relativas ao fim da vida de embalagens Considerations, dilemmas and responsibilities related to packaging refuse

    Directory of Open Access Journals (Sweden)

    Sylmara Lopes Francelino Gonçalves-Dias

    2006-01-01

    Full Text Available A necessidade de equacionar o destino das embalagens, após seu uso original, tem sido crescente nas últimas décadas. Vistas ora como receptáculo de produtos avidamente consumidos, ora como grandes vilãs dos problemas ambientais, as embalagens colocam importantes desafios para o entendimento de sua concepção e revalorização ao fim de sua vida. Este artigo, dessa maneira, pretende promover um diálogo entre os campos de design, sustentabilidade e ciclo de vida das embalagens. Procurando avançar na compreensão das possibilidades, desafios e dilemas da gestão do fim da vida das embalagens, dá ênfase especial às embalagens plásticas em razão do volume crescente dos resíduos sólidos dos domicílios. A revisão da literatura aponta para conceitos e práticas ainda em construção. Assim, este artigo apresenta uma sistematização e estruturação dos principais conceitos, não só resumindo a literatura existente, mas também trazendo alguns exemplos de valorização das embalagens plásticas; são discutidas, ainda, legislações do contexto internacional e brasileiro. Entretanto, é possível antecipar que o tema pressupõe aumento do nível de informação da população, eliminação do desperdício desde a concepção, desenvolvimento de tecnologias, responsabilidades compartilhadas, reciclagem, mas acima de tudo mudança no padrão comportamental da sociedade atual.The disposal of discarded packaging is of growing concern in recent decades. Alternately viewed as containers of products avidly consumed or as an environmental villain, packaging presents important challenges to understanding both the concept and destination after use. A dialog involving package design and life cycle as well as sustainability was promoted to advance understanding of possibilities, challenges and dilemmas of managing final disposition. Plastic packaging was emphasized because of the growing volume of domestic solid waste. Literature reviewed pointed

  17. Agricultural matrices affect ground ant assemblage composition inside forest fragments.

    Directory of Open Access Journals (Sweden)

    Diego Santana Assis

    Full Text Available The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates; sugarcane (3; and pasture (3. At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart. Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.

  18. Agricultural matrices affect ground ant assemblage composition inside forest fragments.

    Science.gov (United States)

    Assis, Diego Santana; Dos Santos, Iracenir Andrade; Ramos, Flavio Nunes; Barrios-Rojas, Katty Elena; Majer, Jonathan David; Vilela, Evaldo Ferreira

    2018-01-01

    The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices) on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates); sugarcane (3); and pasture (3). At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart). Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.

  19. Characterization of actinobacteria associated with three ant-plant mutualisms.

    Science.gov (United States)

    Hanshew, Alissa S; McDonald, Bradon R; Díaz Díaz, Carol; Djiéto-Lordon, Champlain; Blatrix, Rumsaïs; Currie, Cameron R

    2015-01-01

    Ant-plant mutualisms are conspicuous and ecologically important components of tropical ecosystems that remain largely unexplored in terms of insect-associated microbial communities. Recent work has revealed that ants in some ant-plant systems cultivate fungi (Chaetothyriales) within their domatia, which are fed to larvae. Using Pseudomyrmex penetrator/Tachigali sp. from French Guiana and Petalomyrmex phylax/Leonardoxa africana and Crematogaster margaritae/Keetia hispida, both from Cameroon, as models, we tested the hypothesis that ant-plant-fungus mutualisms co-occur with culturable Actinobacteria. Using selective media, we isolated 861 putative Actinobacteria from the three systems. All C. margaritae/K. hispida samples had culturable Actinobacteria with a mean of 10.0 colony forming units (CFUs) per sample, while 26 % of P. penetrator/Tachigali samples (mean CFUs 1.3) and 67 % of P. phylax/L. africana samples (mean CFUs 3.6) yielded Actinobacteria. The largest number of CFUs was obtained from P. penetrator workers, P. phylax alates, and C. margaritae pupae. 16S rRNA gene sequencing and phylogenetic analysis revealed the presence of four main clades of Streptomyces and one clade of Nocardioides within these three ant-plant mutualisms. Streptomyces with antifungal properties were isolated from all three systems, suggesting that they could serve as protective symbionts, as found in other insects. In addition, a number of isolates from a clade of Streptomyces associated with P. phylax/L. africana and C. margaritae/K. hispida were capable of degrading cellulose, suggesting that Streptomyces in these systems may serve a nutritional role. Repeated isolation of particular clades of Actinobacteria from two geographically distant locations supports these isolates as residents in ant-plant-fungi niches.

  20. Plant genotype shapes ant-aphid interactions: implications for community structure and indirect plant defense.

    Science.gov (United States)

    Mooney, Kailen A; Agrawal, Anurag A

    2008-06-01

    Little is known about the mechanisms by which plant genotype shapes arthropod community structure. In a field experiment, we measured the effects of milkweed (Asclepias syriaca) genotype and ants on milkweed arthropods. Populations of the ant-tended aphid Aphis asclepiadis and the untended aphid Myzocallis asclepiadis varied eight- to 18-fold among milkweed genotypes, depending on aphid species and whether ants were present. There was no milkweed effect on predatory arthropods. Ants increased Aphis abundance 59%, decreased Myzocallis abundance 52%, and decreased predator abundance 56%. Milkweed genotype indirectly influenced ants via direct effects on Aphis and Myzocallis abundance. Milkweed genotype also modified ant-aphid interactions, influencing the number of ants attracted per Aphis and Myzocallis. While ant effects on Myzocallis were consistently negative, effects on Aphis ranged from antagonistic to mutualistic among milkweed genotypes. As a consequence of milkweed effects on ant-aphid interactions, ant abundance varied 13-fold among milkweed genotypes, and monarch caterpillar survival was negatively correlated with genetic variation in ant abundance. We speculate that heritable variation in milkweed phloem sap drives these effects on aphids, ants, and caterpillars. In summary, milkweed exerts genetic control over the interactions between aphids and an ant that provides defense against foliage-feeding caterpillars.

  1. Intrapopulation differences in ant eating in the mountain gorillas of Bwindi Impenetrable National Park, Uganda.

    Science.gov (United States)

    Ganas, Jessica; Robbins, Martha M

    2004-10-01

    Variability in ant eating has been observed in several populations of eastern and western gorillas. We investigated the occurrence of ant (Dorylus sp.) eating in two groups of mountain gorillas (Gorilla beringei beringei) with overlapping home ranges within Bwindi Impenetrable National Park, Uganda from September 2001 to August 2002. We calculated the frequency of ant eating by an indirect method of analyzing fecal samples from silverbacks, adult females, and juveniles. One group consumed ants significantly more often than the other (3.3 vs 17.6% of days sampled). Furthermore, the group that consumed ants more often also consumed them on a seasonal basis (September-February monthly range: 0-8%; March-August monthly range: 30-42.9%). Finally, females and juveniles of this group consumed ants significantly more often than did the silverback (total samples containing ants: silverback, 2.1%; adult female, 13.2%; juvenile, 11.2%). Differences in ant eating between groups are likely due to variability in use of habitats where ants occur (particularly secondary forests). Surveys of ant densities in differing habitats, nutritional analysis of ants, and quantification of the amount of ants in their diets are necessary to understand if ant consumption is due to availability, nutritional value, group traditions, or taste preference.

  2. Five new records of ants (Hymenoptera: Formicidae) from Morocco.

    Science.gov (United States)

    Taheri, Ahmed; Reyes-López, Joaquin L

    2015-01-01

    A recent catalogue of the rich ant fauna of Morocco included 214 species, with later studies adding an additional 12 species. Following recent fieldwork in the north of Morocco, we report five new records for the country (Plagiolepis pygmaea Latreille, 1798, Ponera testacea Emery, 1895, Strumigenys tenuipilis Emery, 1915, Temnothorax pardoi Tinaut, 1987, and Tetramorium parvioculum Guillem & Bensusan, 2009) and we present new data on the distribution and natural history of six additional species. This work brings the total number of ants known from Morocco to 233, taking into account two species which were omitted in the list of Cagniant. © Crown copyright 2015.

  3. Core Business Selection Based on Ant Colony Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Yu Lan

    2014-01-01

    Full Text Available Core business is the most important business to the enterprise in diversified business. In this paper, we first introduce the definition and characteristics of the core business and then descript the ant colony clustering algorithm. In order to test the effectiveness of the proposed method, Tianjin Port Logistics Development Co., Ltd. is selected as the research object. Based on the current situation of the development of the company, the core business of the company can be acquired by ant colony clustering algorithm. Thus, the results indicate that the proposed method is an effective way to determine the core business for company.

  4. Significance of chemical recognition cues is context dependent in ants

    DEFF Research Database (Denmark)

    Bos, N.; Guerrieri, F.J.; d'Ettorre, P.

    2010-01-01

    signatures, composed primarily of long-chain cuticular hydrocarbons. These signatures are colony specific and allow discrimination between nestmates and non-nestmates. Nevertheless, the mechanisms underlying detection, perception and information processing of chemical signatures are poorly understood. It has...... context, affects aggression against non-nestmates carrying the hydrocarbon profile associated with food. Individual ant workers were able to associate the non-nestmate chemical profile with food. However, conditioned ants were still aggressive when encountering a non-nestmate carrying the odour profile...

  5. Mutualistic fungi control crop diversity in fungus-growing ants

    DEFF Research Database (Denmark)

    Poulsen, Michael; Boomsma, Jacobus J

    2005-01-01

    Leaf-cutting ants rear clonal fungi for food and transmit the fungi from mother to daughter colonies so that symbiont mixing and conflict, which result from competition between genetically different clones, are avoided. Here we show that despite millions of years of predominantly vertical...... transmission, the domesticated fungi actively reject mycelial fragments from neighboring colonies, and that the strength of these reactions are in proportion to the overall genetic difference between these symbionts. Fungal incompatibility compounds remain intact during ant digestion, so that fecal droplets...

  6. Are queen ants inhibited by their own pheromone?

    DEFF Research Database (Denmark)

    Holman, L.; Leroy, C.; Jørgensen, Charlotte

    2013-01-01

    . Communication in social insects is predominantly chemical, and the mechanisms regulating processes such as reproductive division of labor are becoming increasingly well understood. Recently, a queen cuticular hydrocarbon (3-MeC31) that inhibits worker reproduction and aggression was isolated in the ant Lasius...... niger. Here, we find that this pheromone also has a weak negative effect on queen productivity and oogenesis. Because 3-MeC31 is present on both queens and their brood, we suggest that it is used by ants of both castes to adjust their fecundity to the amount of developing brood and the presence of other...

  7. Sperm storage induces an immunity cost in ants

    DEFF Research Database (Denmark)

    Baer, Boris; Armitage, Sophie A O; Boomsma, Jacobus J

    2006-01-01

    Ant queens are among the most long-lived insects known. They mate early in adult life and maintain millions of viable sperm in their sperm storage organ until they die many years later. Because they never re-mate, the reproductive success of queens is ultimately sperm-limited, but it is not known...... what selective forces determine the upper limit to sperm storage. Here we show that sperm storage carries a significant cost of reduced immunity during colony founding. Newly mated queens of the leaf-cutting ant Atta colombica upregulate their immune response shortly after completing their nest burrow...

  8. The search rate of the African weaver ant in cashew

    DEFF Research Database (Denmark)

    Henriksen, Signe; Axelsen, Jørgen Aagaard; Lemming, Katrine Hansen

    2015-01-01

    Oecophylla longinoda is a species of eusocial colony living ants that prey upon other insects to feed their larva. Many of these insects are considered pests. An ecosystem model of the interactions between an O. longinoda colony and its potential prey is under construction by the team behind...... this article, and it is unknown which functional response equations are useful for eusocial insect colonies. We investigated the search rate of O. longinoda using artificial feeding experiments in a Tanzanian cashew (Anacardium occidentale L.) orchard to determine the search efficiency of the ants...

  9. Application of ant colony optimization in NPP classification fault location

    International Nuclear Information System (INIS)

    Xie Chunli; Liu Yongkuo; Xia Hong

    2009-01-01

    Nuclear Power Plant is a highly complex structural system with high safety requirements. Fault location appears to be particularly important to enhance its safety. Ant Colony Optimization is a new type of optimization algorithm, which is used in the fault location and classification of nuclear power plants in this paper. Taking the main coolant system of the first loop as the study object, using VB6.0 programming technology, the NPP fault location system is designed, and is tested against the related data in the literature. Test results show that the ant colony optimization can be used in the accurate classification fault location in the nuclear power plants. (authors)

  10. Sex-specific kleptoparasitic foraging in ant-eating spiders

    DEFF Research Database (Denmark)

    Martisová, Martina; Bilde, T.; Pekar, Stano

    2009-01-01

    . To investigate this hypothesis, we studied the effect of sex and life history stage on the frequency of kleptoparasitism in ant-eating spiders of the genus Zodarion in the field. These spiders use a special capture technique involving a quick attack on an ant that is left unguarded by spiders for several minutes......, providing ample opportunities for kleptoparasitism. We found that adult females consistently hunted actively, while adult males ceased active prey capture and instead engaged in kleptoparasitism. Juvenile spiders were active hunters irrespective of sex. Consistent with an ontogenetic shift in foraging...

  11. Conflict over reproduction in an ant-plant symbiosis: why Allomerus octoarticulatus ants sterilize Cordia nodosa trees.

    Science.gov (United States)

    Frederickson, Megan E

    2009-05-01

    The evolutionary stability of mutualism is thought to depend on how well the fitness interests of partners are aligned. Because most ant-myrmecophyte mutualisms are persistent and horizontally transmitted, partners share an interest in growth but not in reproduction. Resources invested in reproduction are unavailable for growth, giving rise to a conflict of interest between partners. I investigated whether this explains why Allomerus octoarticulatus ants sterilize Cordia nodosa trees. Allomerus octoarticulatus nests in the hollow stem domatia of C. nodosa. Workers protect C. nodosa leaves against herbivores but destroy inflorescences. Using C. nodosa trees with Azteca ants, which do not sterilize their hosts, I cut inflorescences off trees to simulate sterilization by A. octoarticulatus. Sterilized C. nodosa grew faster than control trees, providing evidence for a trade-off between growth and reproduction. Allomerus octoarticulatus manipulates this trade-off to its advantage; sterilized trees produce more domatia and can house larger, more fecund colonies.

  12. DARWIN Y LOS DILEMAS SOCIALES

    Directory of Open Access Journals (Sweden)

    Alejandro Rosas

    2009-10-01

      I describe the project of a Darwinian explanation of morality following Darwin’s basic ideas as expressed in The Descent of Man. In contrast to the traditional interpretation, I argue that Darwin did not assume, nor is it necessary to assume in a Darwinian perspective, an inevitable conflict between individual and group selection in the explanation of morality. Both operate in synergy to favor traits that support moral behavior. I also argue that two teachings result from this Darwinian project, one for moral philosophy and the other for the theory of natural selection. The first puts social dilemmas in the heart of human morality; the second puts cooperation in the core of natural selection. I illustrate the second point with recent research into the evolution of multi-cellular organisms.

  13. The genomic impact of 100 million years of social evolution in seven ant species

    DEFF Research Database (Denmark)

    Gadau, Jürgen; Helmkampf, Martin; Nygaard, Sanne

    2012-01-01

    Ants (Hymenoptera, Formicidae) represent one of the most successful eusocial taxa in terms of both their geographic distribution and species number. The publication of seven ant genomes within the past year was a quantum leap for socio- and ant genomics. The diversity of social organization in ants...... between social and solitary insects, as well as among ant species. Altogether, these seven ant genomes open exciting new research avenues and opportunities for understanding the genetic basis and regulation of social species, and adaptive complex systems in general....... makes them excellent model organisms to study the evolution of social systems. Comparing the ant genomes with those of the honeybee, a lineage that evolved eusociality independently from ants, and solitary insects suggests that there are significant differences in key aspects of genome organization...

  14. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    Science.gov (United States)

    Neonicotinoid insecticides are commonly used in managing pest ants, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicot...

  15. Live and let die: why fighter males of the ant Cardiocondyla kill each other but tolerate their winged rivals

    DEFF Research Database (Denmark)

    Anderson, Carl; Cremer, Sylvia Maria; Heinze, Jürgen

    2003-01-01

    alternative dispersal tactics, ants, Cardiocondyla, ergatoid males, fighting, male dimorphism, toleration......alternative dispersal tactics, ants, Cardiocondyla, ergatoid males, fighting, male dimorphism, toleration...

  16. Olfactory memory established during trophallaxis affects food search behaviour in ants

    OpenAIRE

    Provecho, Y.; Josens, R.

    2009-01-01

    Camponotus mus ants can associate sucrose and odour at the source during successive foraging cycles and use this memory to locate the nectar in the absence of other cues. These ants perform conspicuous trophallactic behaviour during recruitment while foraging for nectar. In this work, we studied whether Camponotus mus ants are able to establish this odour-sucrose association in the social context of trophallaxis and we evaluated this memory in another context previously experienced by the ant...

  17. Individual Rules for Trail Pattern Formation in Argentine Ants (Linepithema humile)

    OpenAIRE

    Perna, Andrea; Granovskiy, Boris; Garnier, Simon; Nicolis, Stamatios C.; Labédan, Marjorie; Theraulaz, Guy; Fourcassié, Vincent; Sumpter, David J. T.

    2012-01-01

    We studied the formation of trail patterns by Argentine ants exploring an empty arena. Using a novel imaging and analysis technique we estimated pheromone concentrations at all spatial positions in the experimental arena and at different times. Then we derived the response function of individual ants to pheromone concentrations by looking at correlations between concentrations and changes in speed or direction of the ants. Ants were found to turn in response to local pheromone concentrations,...

  18. 9 CFR 381.71 - Condemnation on ante mortem inspection.

    Science.gov (United States)

    2010-01-01

    ... dressed, nor shall they be conveyed into any department of the official establishment where poultry... AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Ante Mortem Inspection § 381.71...

  19. Application of ant colony optimisation in distribution transformer sizing

    African Journals Online (AJOL)

    This study proposes an optimisation method for transformer sizing in power system using ant colony optimisation and a verification of the process by MATLAB software. The aim is to address the issue of transformer sizing which is a major challenge affecting its effective performance, longevity, huge capital cost and power ...

  20. Formulation des betons autopla~ants : Optimisation du squelette ...

    African Journals Online (AJOL)

    Formulation des betons autopla~ants : Optimisation du squelette granulaire par la methode graphique de Dreux - Gorisse. Fatiha Boumaza - Zeraoulia* & Mourad Behim. Laboratoire Materiaux, Geo - Materiaux et Environnement - Departement de Genie Civil. Universite Badji Mokhtar Annaba - BP 12, 23000 Annaba - ...

  1. Ant and rattan associations in forest of tropical Africa | Sunderland ...

    African Journals Online (AJOL)

    Recent fieldwork aimed at increasing our knowledge of the taxonomy and ecology of African rattans has indicated that there is a significant relationship between these climbing palms and a number of ant species. A closer investigation into this relationship has found that the morphology of rattan palms is particularly ...

  2. Are workers of Atta leafcutter ants capable of reproduction?

    DEFF Research Database (Denmark)

    Dijkstra, Michiel Bendert; Boomsma, Jacobus Jan

    2006-01-01

    ovaries. Workers of Atta leafcutter ants only lay trophic eggs in queenright colonies. Although Atta colonies are commonly kept at universities, museums, and zoos, no reports of worker sons in orphaned colonies exist, suggesting that Atta workers are infertile. To explicitly test this, we created eleven...

  3. Does the afrotropical army ant Dorylus (Anomma) molestus go ...

    African Journals Online (AJOL)

    Swarm-raiding army ants are extremely polyphagous nomadic predators inhabiting tropical forests. They are considered keystone species because their raids can regulate the population dynamics of their prey and because a plethora of both invertebrate and vertebrate species are obligatorily or facultatively associated with ...

  4. Biogeography of Puerto Rican ants: a non-equilibrium case?

    Science.gov (United States)

    J.A. Torres; R.R. Snelling

    1997-01-01

    Ants were studied on Puerto Rico and 44 islands surrounding Puerto Rico. Habitat diversity was the best predictor of the number of species per island and the distributions of species followed a nested subset pattern. The number of extinctions per island was low, approximately 1 to 2 extinctions per island in a period of 18 years, and the rates of colonization seem to...

  5. Recurrent bridgehead effects accelerate global alien ant spread

    Science.gov (United States)

    Cleo Bertelsmeier; Sébastien Ollier; Andrew M. Liebhold; Eckehard G. Brockerhoff; Darren Ward; Laurent Keller

    2018-01-01

    Biological invasions are a major threat to biological diversity, agriculture, and human health. To predict and prevent new invasions, it is crucial to develop a better understanding of the drivers of the invasion process. The analysis of 4,533 border interception events revealed that at least 51 different alien ant species were intercepted at US ports over a period of...

  6. Ultrastructure of antennal sensillae of the samsum ant ...

    African Journals Online (AJOL)

    Jane

    2010-10-11

    Oct 11, 2010 ... subsequently may form the basis in producing its effective control measure in future. ... persons that may deteriorate into serious health condi- tions. ... with the behavioral ecology of ants (Faucheux et al.,. 2006) ... Basiconic type acts as food and CO2 receptor, trichoids ..... Sex pheromone perception in male.

  7. Energy Efficient Routing in Wireless Sensor Networks based on Ant ...

    African Journals Online (AJOL)

    PROF. O. E. OSUAGWU

    2013-09-01

    Sep 1, 2013 ... improved Ant System and their application in WSN routing process. The simulation results show ... and Mobile ad-hoc networks (MANETs) are inappropriate for ... Dorigo in 1992 in his PhD thesis, the first algorithm was aiming ...

  8. Urban physiology: city ants possess high heat tolerance.

    Directory of Open Access Journals (Sweden)

    Michael J Angilletta

    Full Text Available Urbanization has caused regional increases in temperature that exceed those measured on a global scale, leading to urban heat islands as much as 12 degrees C hotter than their surroundings. Optimality models predict ectotherms in urban areas should tolerate heat better and cold worse than ectotherms in rural areas. We tested these predications by measuring heat and cold tolerances of leaf-cutter ants from South America's largest city (São Paulo, Brazil. Specifically, we compared thermal tolerances of ants from inside and outside of the city. Knock-down resistance and chill-coma recovery were used as indicators of heat and cold tolerances, respectively. Ants from within the city took 20% longer to lose mobility at 42 degrees C than ants from outside the city. Interestingly, greater heat tolerance came at no obvious expense of cold tolerance; hence, our observations only partially support current theory. Our results indicate that thermal tolerances of some organisms can respond to rapid changes in climate. Predictive models should account for acclimatory and evolutionary responses during climate change.

  9. Irving Babbitti humanismi põhijooned / Ants Oras

    Index Scriptorium Estoniae

    Oras, Ants

    2003-01-01

    Varem ilmunud: rmt.: "Kultuuri ja teaduse teilt: mõtteid ja uurimusi Tartu Ülikooli 300-nda mälestusaasta puhuks". Tartu : Loodus, 1932, lk. 144-153 ; Ants Oras, "Irving Babbitt' i humanismi põhijooned: äratrükk koguteosest "Kultuuri ja teaduse teilt"". Tartu, 1932

  10. Ant-egg cataract. An electron microscopic study

    DEFF Research Database (Denmark)

    Schrøder, H D; Nissen, S H

    1979-01-01

    an intermittent growth of the structure. In the ant-eggs, as well as in some areas separate from these, membrane limited cytoplasmic bodies could be seen in many cases, the membranes of which were partly joint and partly separated by an electron dense material. It is suggested that the calcifications seen...

  11. Compass cues used by a nocturnal bull ant, Myrmecia midas.

    Science.gov (United States)

    Freas, Cody A; Narendra, Ajay; Cheng, Ken

    2017-05-01

    Ants use both terrestrial landmarks and celestial cues to navigate to and from their nest location. These cues persist even as light levels drop during the twilight/night. Here, we determined the compass cues used by a nocturnal bull ant, Myrmecia midas , in which the majority of individuals begin foraging during the evening twilight period. Myrmecia midas foragers with vectors of ≤5   m when displaced to unfamiliar locations did not follow the home vector, but instead showed random heading directions. Foragers with larger home vectors (≥10   m) oriented towards the fictive nest, indicating a possible increase in cue strength with vector length. When the ants were displaced locally to create a conflict between the home direction indicated by the path integrator and terrestrial landmarks, foragers oriented using landmark information exclusively and ignored any accumulated home vector regardless of vector length. When the visual landmarks at the local displacement site were blocked, foragers were unable to orient to the nest direction and their heading directions were randomly distributed. Myrmecia midas ants typically nest at the base of the tree and some individuals forage on the same tree. Foragers collected on the nest tree during evening twilight were unable to orient towards the nest after small lateral displacements away from the nest. This suggests the possibility of high tree fidelity and an inability to extrapolate landmark compass cues from information collected on the tree and at the nest site to close displacement sites. © 2017. Published by The Company of Biologists Ltd.

  12. Variability in individual activity bursts improves ant foraging success.

    Science.gov (United States)

    Campos, Daniel; Bartumeus, Frederic; Méndez, Vicenç; Andrade, José S; Espadaler, Xavier

    2016-12-01

    Using experimental and computational methods, we study the role of behavioural variability in activity bursts (or temporal activity patterns) for individual and collective regulation of foraging in A. senilis ants. First, foraging experiments were carried out under special conditions (low densities of ants and food and absence of external cues or stimuli) where individual-based strategies are most prevalent. By using marked individuals and recording all foraging trajectories, we were then able to precisely quantify behavioural variability among individuals. Our main conclusions are that (i) variability of ant trajectories (turning angles, speed, etc.) is low compared with variability of temporal activity profiles, and (ii) this variability seems to be driven by plasticity of individual behaviour through time, rather than the presence of fixed behavioural stereotypes or specialists within the group. The statistical measures obtained from these experimental foraging patterns are then used to build a general agent-based model (ABM) which includes the most relevant properties of ant foraging under natural conditions, including recruitment through pheromone communication. Using the ABM, we are able to provide computational evidence that the characteristics of individual variability observed in our experiments can provide a functional advantage (in terms of foraging success) to the group; thus, we propose the biological basis underpinning our observations. Altogether, our study reveals the potential utility of experiments under simplified (laboratory) conditions for understanding information-gathering in biological systems. © 2016 The Author(s).

  13. Ant Colony Optimization and the Minimum Cut Problem

    DEFF Research Database (Denmark)

    Kötzing, Timo; Lehre, Per Kristian; Neumann, Frank

    2010-01-01

    Ant Colony Optimization (ACO) is a powerful metaheuristic for solving combinatorial optimization problems. With this paper we contribute to the theoretical understanding of this kind of algorithm by investigating the classical minimum cut problem. An ACO algorithm similar to the one that was prov...

  14. Evolutionary transitions in enzyme activity of ant fungus gardens.

    Science.gov (United States)

    De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G; Boomsma, Jacobus J

    2010-07-01

    Fungus-growing (attine) ants and their fungal symbionts passed through several evolutionary transitions during their 50 million year old evolutionary history. The basal attine lineages often shifted between two main cultivar clades, whereas the derived higher-attine lineages maintained an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens are targeted primarily toward partial degradation of plant cell walls, reflecting a plesiomorphic state of nondomesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major breakdown of cell walls. The adaptive significance of the lower-attine symbiont shifts remains unclear. One of these shifts was obligate, but digestive advantages remained ambiguous, whereas the other remained facultative despite providing greater digestive efficiency.

  15. An object-oriented model for ex ante accounting information

    NARCIS (Netherlands)

    Verdaasdonk, P.J.A.

    2003-01-01

    Present accounting data models such as the Research-Event-Agent (REA) model merely focus on the modeling of static accounting phenomena. In this paper, it is argued that these models are not able to provide relevant ex ante accounting data for operations management decisions. These decisions require

  16. A model of ant route navigation driven by scene familiarity.

    Directory of Open Access Journals (Sweden)

    Bart Baddeley

    2012-01-01

    Full Text Available In this paper we propose a model of visually guided route navigation in ants that captures the known properties of real behaviour whilst retaining mechanistic simplicity and thus biological plausibility. For an ant, the coupling of movement and viewing direction means that a familiar view specifies a familiar direction of movement. Since the views experienced along a habitual route will be more familiar, route navigation can be re-cast as a search for familiar views. This search can be performed with a simple scanning routine, a behaviour that ants have been observed to perform. We test this proposed route navigation strategy in simulation, by learning a series of routes through visually cluttered environments consisting of objects that are only distinguishable as silhouettes against the sky. In the first instance we determine view familiarity by exhaustive comparison with the set of views experienced during training. In further experiments we train an artificial neural network to perform familiarity discrimination using the training views. Our results indicate that, not only is the approach successful, but also that the routes that are learnt show many of the characteristics of the routes of desert ants. As such, we believe the model represents the only detailed and complete model of insect route guidance to date. What is more, the model provides a general demonstration that visually guided routes can be produced with parsimonious mechanisms that do not specify when or what to learn, nor separate routes into sequences of waypoints.

  17. Rethinking crop-disease management in fungus-growing ants

    NARCIS (Netherlands)

    Boomsma, J.J.; Aanen, D.K.

    2009-01-01

    Ant fungus farming has become a prominent model for studying the evolution of mutualistic cooperation, with recent advances in reconstructing the evolutionary origin and elaborations of the symbiosis (1, 2), discovering additional partners and clarifying their interactions (3, 4), and analyzing

  18. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    Science.gov (United States)

    Pringle, Elizabeth G.; Akçay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  19. Ant-inspired density estimation via random walks.

    Science.gov (United States)

    Musco, Cameron; Su, Hsin-Hao; Lynch, Nancy A

    2017-10-03

    Many ant species use distributed population density estimation in applications ranging from quorum sensing, to task allocation, to appraisal of enemy colony strength. It has been shown that ants estimate local population density by tracking encounter rates: The higher the density, the more often the ants bump into each other. We study distributed density estimation from a theoretical perspective. We prove that a group of anonymous agents randomly walking on a grid are able to estimate their density within a small multiplicative error in few steps by measuring their rates of encounter with other agents. Despite dependencies inherent in the fact that nearby agents may collide repeatedly (and, worse, cannot recognize when this happens), our bound nearly matches what would be required to estimate density by independently sampling grid locations. From a biological perspective, our work helps shed light on how ants and other social insects can obtain relatively accurate density estimates via encounter rates. From a technical perspective, our analysis provides tools for understanding complex dependencies in the collision probabilities of multiple random walks. We bound the strength of these dependencies using local mixing properties of the underlying graph. Our results extend beyond the grid to more general graphs, and we discuss applications to size estimation for social networks, density estimation for robot swarms, and random walk-based sampling for sensor networks.

  20. Ants Oras ja eesti Shakespeare'i-kultuur / Evelin Banhard

    Index Scriptorium Estoniae

    Banhard, Evelin

    2008-01-01

    Artikkel käsitleb Ants Orase rolli William Shakespeare'i pärandi tõlkija ja tutvustajana. Analüüsitakse Orase töid eesti kultuuriajakirjanduses 1920. ja 1930. aastatel ning tema hilisemaid, paguluses kirjutatud arvustusi

  1. INTRODUCTION The tailor or weaver ants of genus Oecophylla ...

    African Journals Online (AJOL)

    smaragdina which is a sister species and ecological equivalent of ... Stability in population of Oecophylla in BSP and PG over 13 years suggests that weaver ant .... between the two years were significant at 95% confidence ..... over time is dependent on the nature of the perturbation. ... longinoda in relation to territorility and.

  2. Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis

    DEFF Research Database (Denmark)

    Oh, Dong-Chan; Poulsen, Michael; Currie, Cameron R

    2009-01-01

    Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective antibiotics to defend that fungus from specialized fungal parasites. We have analyzed one such system at the molecular level and found...

  3. ANTS AS BIOLOGICAL INDICATORS FOR MONITORING CHANGES IN ARID ENVIRONMENTS: LESSONS FOR MONITORING PROTECTED AREAS

    Science.gov (United States)

    The responses of ant communities to structural change (removal of an invasive were studied in a replicated experiment in a Chihuahuan Desert grassland. The results from sampling of ant communities by pit-fall trapping were validated by mapping ant colonies on the experimental plo...

  4. Advances in Research on the Venom Chemistry of Imported Fire Ants

    Science.gov (United States)

    Workers of the imported fire ants, including red imported fire ants, Solenopsis invicta Buren, black imported fire ants, S. richteri Forel, and their hybrid (S. invicta × S. richteri), are vicious stingers. Since the venomous sting is a significant medical problem to humans, the chemistry of import...

  5. Dispersal for survival: some observations on the trunk ant (Formica truncorum Fabricius)

    NARCIS (Netherlands)

    Mabelis, A.A.; Korczynska, J.

    2001-01-01

    The survival chance of the trunk ant (Formica truncorum) is compared with the survival chance of two other species of red wood ants: F.rufa and F.polyctena. Nest populations of F.truncorum are much smaller than nest populations of the other red wood ant species, which makes the species a weaker

  6. The genome of the fire ant Solenopsis invicta

    DEFF Research Database (Denmark)

    Wurm, Yannick; Wang, John; Riba-Grognuz, Oksana

    2011-01-01

    Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta, are also major pests. Here, we present a draft genome of S. invicta, assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothe...

  7. The effects of age and social interactions on innate immunity in a leaf-cutting ant

    DEFF Research Database (Denmark)

    Armitage, S.A.O.; Boomsma, J.J.

    2010-01-01

    defence is affected by both age and the short-term presence or absence of nestmates in the leaf-cutting ant Acromyrmex octospinosus. We predicted that older ants would show immune senescence and that group living may result in prophylactic differences in immune defence compared to solitarily kept ants. We...

  8. The effectiveness of weaver ant (Oecophylla smaragdina) biocontrol in Southeast Asian citrus and mango

    DEFF Research Database (Denmark)

    Offenberg, Joachim; Cuc, Nguyen Thi Thu; Wiwatwitaya, Decha

    2013-01-01

    Oecophylla ants may protect tropical plantation crops against pests. Cost-benefit studies comparing ant-based protection with conventional methods are needed to assess whether it is economically viable. Here we contrast profits in ant and chemically protected plots in a Thai and a Vietnamese citrus...

  9. Towards a better understanding of the evolution of specialized parasites of fungus-growing ant crops

    DEFF Research Database (Denmark)

    Yek, Sze Huei; Boomsma, Jacobus Jan; Poulsen, Michael

    2012-01-01

    Fungus-growing ants have interacted and partly coevolved with specialised microfungal parasites of the genus Escovopsis since the origin of ant fungiculture about 50 million years ago. Here, we review the recent progress in understanding the patterns of specificity of this ant-parasite associatio...

  10. Ant-Related Oviposition and Larval Performance in a Myrmecophilous Lycaenid

    Directory of Open Access Journals (Sweden)

    Matthew D. Trager

    2013-01-01

    Full Text Available We experimentally assessed ant-related oviposition and larval performance in the Miami blue butterfly (Cyclargus thomasi bethunebakeri. Ant tending had sex-dependent effects on most measures of larval growth: female larvae generally benefitted from increased tending frequency whereas male larvae were usually unaffected. The larger size of female larvae tended by ants resulted in a substantial predicted increase in lifetime egg production. Oviposition by adult females that were tended by C. floridanus ants as larvae was similar between host plants with or without ants. However, they laid relatively more eggs on plants with ants than did females raised without ants, which laid less than a third of their eggs on plants with ants present. In summary, we found conditional benefits for larvae tended by ants that were not accompanied by oviposition preference for plants with ants present, which is a reasonable result for a system in which ant presence at the time of oviposition is not a reliable indicator of future ant presence. More broadly, our results emphasize the importance of considering the consequences of variation in interspecific interactions, life history traits, and multiple measures of performance when evaluating the costs and benefits of mutualistic relationships.

  11. Drowning out the protection racket: partner manipulation or drought can strengthen ant-plant mutualism.

    Science.gov (United States)

    Denison, R Ford

    2014-07-01

    Two recent reports discuss interactions between plants and ants that defend them from herbivores. Acacia trees provide their ant bodyguards with a diet that reduces their ability to benefit from alternate hosts. Provisioning of ants by Cordia trees during drought may buy insurance against extreme defoliation events, not just average-year benefits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. The interplay between scent trails and group-mass recruitment systems in ants

    NARCIS (Netherlands)

    Planque, R.; van den Berg, G.J.B.; Franks, N.R.

    2013-01-01

    Large ant colonies invariably use effective scent trails to guide copious ant numbers to food sources. The success of mass recruitment hinges on the involvement of many colony members to lay powerful trails. However, many ant colonies start off as single queens. How do these same colonies forage

  13. Temperature limits trail following behaviour through pheromone decay in ants

    Science.gov (United States)

    van Oudenhove, Louise; Billoir, Elise; Boulay, Raphaël; Bernstein, Carlos; Cerdá, Xim

    2011-12-01

    In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation. Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment, more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures.

  14. Ants can learn to forage on one-way trails.

    Directory of Open Access Journals (Sweden)

    Pedro Leite Ribeiro

    Full Text Available The trails formed by many ant species between nest and food source are two-way roads on which outgoing and returning workers meet and touch each other all along. The way to get back home, after grasping a food load, is to take the same route on which they have arrived from the nest. In many species such trails are chemically marked by pheromones providing orientation cues for the ants to find their way. Other species rely on their vision and use landmarks as cues. We have developed a method to stop foraging ants from shuttling on two-way trails. The only way to forage is to take two separate roads, as they cannot go back on their steps after arriving at the food or at the nest. The condition qualifies as a problem because all their orientation cues -- chemical, visual or any other -- are disrupted, as all of them cannot but lead the ants back to the route on which they arrived. We have found that workers of the leaf-cutting ant Atta sexdens rubropilosa can solve the problem. They could not only find the alternative way, but also used the unidirectional traffic system to forage effectively. We suggest that their ability is an evolutionary consequence of the need to deal with environmental irregularities that cannot be negotiated by means of excessively stereotyped behavior, and that it is but an example of a widespread phenomenon. We also suggest that our method can be adapted to other species, invertebrate and vertebrate, in the study of orientation, memory, perception, learning and communication.

  15. Necesidades percibidas de atención de salud al adulto mayor desde una perspectiva de género Noted needs of health care to elderly from a gender perspective

    Directory of Open Access Journals (Sweden)

    Aida Rodríguez Cabrera

    2009-12-01

    Full Text Available Introducción: el proceso de envejecimiento ha sido muy acelerado en Cuba, lo que implica demandas crecientes de atención en salud al adulto mayor, y la necesidad de tomar en consideración el enfoque de género para lograr mejores componentes al establecer las políticas de salud. Objetivo: identificar las principales necesidades percibidas de atención en salud de la población de 60 años y más desde una perspectiva de género. Métodos: se realizó un estudio descriptivo transversal en el área de salud del policlínico «Leonilda Tamayo Matos», de la Isla de la Juventud, mediante encuesta, a una muestra aleatoria estratificada de 400 personas de ambos sexos. Resultados: la atención por parte de los Médicos y Enfermeras de la Familia fue referida con falta de sistematicidad y poca disponibilidad de instructores para la atención a actividades del adulto mayor. Resaltan la necesidad de atención a los que viven solos, carencias de salud no satisfechas, e insuficiencias en el seguimiento de las enfermedades, consideraciones de las acciones de salud con independencia del sexo. Conclusiones: existen aspectos de la atención de salud a esta población que deben mejorase y aún hay importantes brechas por resolver. En la atención de salud no se muestran diferencias de género.Introduction: Aging process has been much accelerated in Cuba involving increasing demands of health care to elderly and the need of considering the gender approach to achieve better components to establish health policies. Objective: To identify the major noted of health care of population aged 60 or more from a gender perspective. Methods: A cross-sectional and descriptive study was conducted in health area from the "Leonilda Tamayo Matos" Polyclinic in Isla de la Juventud municipality by survey in a stratified randomized sample including 400 persons of both sexes. Results: Family physicians and nurses care was lacking of systematization and of little availability of

  16. ENTRE FRAGMENTOS E RUÍNAS: O. G. Rego de Carvalho e os dilemas intelectuais de uma geração

    Directory of Open Access Journals (Sweden)

    José Maria Vieira de Andrade

    2015-05-01

    Full Text Available Neste trabalho, discute-se sobre a atuação e a produção intelectual do literato Orlando Geraldo  Rego  de  Carvalho enquanto  pretexto  para  pensarmos  os  dilemas  culturais vivenciados ou experimentados pela  sociedade  teresinense na metade do século XX. Procurando descortinar os nexos essenciais existentes entre as transformações urbanas ocorridas  nessa  época  e  a  experiência  intelectual  protagonizada  por O. G. Rego  de Carvalho, analisa-se nesse estudo, como o referido literato pensou e registrou em seus textos, as tensões, os conflitos e os paradoxos vivenciados pela sociedade local, entre o final dos anos quarenta e início da década de sessenta. Em meio às questões centrais discutidas,  enfatiza-se,  primeiramente,  as  polêmicas  e  os  debates  em  torno  das mudanças  ocorridas  nas  sociabilidades  urbanas  e,  a  relação  existente  entre  essas mudanças e os projetos de renovação da produção literária, elaborados pelos homens de letras. Em seguida, a partir de uma análise da trilogia ficcional do literato, analisa-se a  sensação  de  dilaceramento  e  de  perda  das  referências  vivenciados  por  esses indivíduos, bem como o esforço empreendido por eles para, através da ficção, tentar descortinar  uma  experiência  narrativa  transcendental  e  salvadora.  Depois  de percorridos essa diversidade de textos, evidencia-se que, de modo geral, a atuação e a produção  intelectual  de O. G. Rego  de Carvalho,  traduziu-se  enquanto  registros  de uma experiência histórica de perda e fragmentação que procurava fazer das mudanças ocorridas no período e da passagem do tempo algo menos corrosivo e destruidor. Palavras-chave: História. Literatura. Experiência urbana. O. G. Rego de Carvalho. Absctract This paper, we discuss about  the performance and  intellectual production of  literary Orlando Geraldo Rego de Carvalho as

  17. Elevated atmospheric carbon dioxide concentrations promote ant tending of aphids.

    Science.gov (United States)

    Kremer, Jenni M M; Nooten, Sabine S; Cook, James M; Ryalls, James M W; Barton, Craig V M; Johnson, Scott N

    2018-04-27

    Animal mutualisms, which involve beneficial interactions between individuals of different species, are common in nature. Insect-insect mutualism, for example, is widely regarded as a keystone ecological interaction. Some mutualisms are anticipated to be modified by climate change, but the focus has largely been on plant-microbe and plant-animal mutualisms rather than those between animals. Ant-aphid mutualisms, whereby ants tend aphids to harvest their honeydew excretions and, in return, provide protection for the aphids, are widespread. The mutualism is heavily influenced by the quality and quantity of honeydew produced by aphids, which is directly affected by host plant quality. As predicted increases in concentrations of atmospheric carbon dioxide (eCO 2 ) are widely reported to affect plant nutritional chemistry, this may also alter honeydew quality and hence the nature of ant-aphid mutualisms. Using glasshouse chambers and field-based open-top chambers, we determined the effect of eCO 2 on the growth and nutritional quality (foliar amino acids) of lucerne (Medicago sativa). We determined how cowpea aphid (Aphis craccivora) populations and honeydew production were impacted when feeding on such plants and how this affected the tending behaviour of ants (Iridomyrmex sp.). eCO 2 stimulated plant growth but decreased concentrations of foliar amino acids by 29% and 14% on aphid-infested plants and aphid-free plants, respectively. Despite the deterioration in host plant quality under eCO 2 , aphids maintained performance and populations were unchanged by eCO 2 . Aphids induced higher concentrations of amino acids (glutamine, asparagine, glutamic acid and aspartic acid) important for endosymbiont-mediated synthesis of essential amino acids. Aphids feeding under eCO 2 also produced over three times more honeydew than aphids feeding under ambient CO 2 , suggesting they were imbibing more phloem sap at eCO 2 . The frequency of ant tending of aphids more than doubled in

  18. A phylogenetic perspective on the association between ants (Hymenoptera: Formicidae) and black yeasts (Ascomycota: Chaetothyriales).

    Science.gov (United States)

    Vasse, Marie; Voglmayr, Hermann; Mayer, Veronika; Gueidan, Cécile; Nepel, Maximilian; Moreno, Leandro; de Hoog, Sybren; Selosse, Marc-André; McKey, Doyle; Blatrix, Rumsaïs

    2017-03-15

    The frequency and the geographical extent of symbiotic associations between ants and fungi of the order Chaetothyriales have been highlighted only recently. Using a phylogenetic approach based on seven molecular markers, we showed that ant-associated Chaetothyriales are scattered through the phylogeny of this order. There was no clustering according to geographical origin or to the taxonomy of the ant host. However, strains tended to be clustered according to the type of association with ants: strains from ant-made carton and strains from plant cavities occupied by ants ('domatia') rarely clustered together. Defining molecular operational taxonomic units (MOTUs) with an internal transcribed spacer sequence similarity cut-off of 99% revealed that a single MOTU could be composed of strains collected from various ant species and from several continents. Some ant-associated MOTUs also contained strains isolated from habitats other than ant-associated structures. Altogether, our results suggest that the degree of specialization of the interactions between ants and their fungal partners is highly variable. A better knowledge of the ecology of these interactions and a more comprehensive sampling of the fungal order are needed to elucidate the evolutionary history of mutualistic symbioses between ants and Chaetothyriales. © 2017 The Author(s).

  19. Plant-ants feed their host plant, but above all a fungal symbiont to recycle nitrogen.

    Science.gov (United States)

    Defossez, Emmanuel; Djiéto-Lordon, Champlain; McKey, Doyle; Selosse, Marc-André; Blatrix, Rumsaïs

    2011-05-07

    In ant-plant symbioses, plants provide symbiotic ants with food and specialized nesting cavities (called domatia). In many ant-plant symbioses, a fungal patch grows within each domatium. The symbiotic nature of the fungal association has been shown in the ant-plant Leonardoxa africana and its protective mutualist ant Petalomyrmex phylax. To decipher trophic fluxes among the three partners, food enriched in (13)C and (15)N was given to the ants and tracked in the different parts of the symbiosis up to 660 days later. The plant received a small, but significant, amount of nitrogen from the ants. However, the ants fed more intensively the fungus. The pattern of isotope enrichment in the system indicated an ant behaviour that functions specifically to feed the fungus. After 660 days, the introduced nitrogen was still present in the system and homogeneously distributed among ant, plant and fungal compartments, indicating efficient recycling within the symbiosis. Another experiment showed that the plant surface absorbed nutrients (in the form of simple molecules) whether or not it is coated by fungus. Our study provides arguments for a mutualistic status of the fungal associate and a framework for investigating the previously unsuspected complexity of food webs in ant-plant mutualisms.

  20. Heat-induced symmetry breaking in ant (Hymenoptera: Formicidae escape behavior.

    Directory of Open Access Journals (Sweden)

    Yuan-Kai Chung

    Full Text Available The collective egress of social insects is important in dangerous situations such as natural disasters or enemy attacks. Some studies have described the phenomenon of symmetry breaking in ants, with two exits induced by a repellent. However, whether symmetry breaking occurs under high temperature conditions, which are a common abiotic stress, remains unknown. In our study, we deposited a group of Polyrhachis dives ants on a heated platform and counted the number of escaping ants with two identical exits. We discovered that ants asymmetrically escaped through two exits when the temperature of the heated platform was >32.75°C. The degree of asymmetry increased linearly with the temperature of the platform. Furthermore, the higher the temperature of heated platform was, the more ants escaped from the heated platform. However, the number of escaping ants decreased for 3 min when the temperature was higher than the critical thermal limit (39.46°C, which is the threshold for ants to endure high temperature without a loss of performance. Moreover, the ants tended to form small groups to escape from the thermal stress. A preparatory formation of ant grouping was observed before they reached the exit, indicating that the ants actively clustered rather than accidentally gathered at the exits to escape. We suggest that a combination of individual and grouping ants may help to optimize the likelihood of survival during evacuation.

  1. Uni-directional trail sharing by two species of ants a Monte Carlo study

    International Nuclear Information System (INIS)

    Kunduraci, T; Kayacan, O

    2015-01-01

    We study insect traffic, specifically ant traffic on a uni-directional trail which is shared by two species of ants, one of which is ‘good’ at smelling and the other ‘poor’. The two distinct species of ants are placed mixed on the same trail and individuals of both are permitted to make a U-turn when they encounter another ant in front of them. The theoretical scheme for the ant traffic is based on an asymmetric simple exclusion model. The ant traffic on the uni-directional trail is studied as a function of the number of ‘good-smelling’ ants and the evaporation probability of pheromones by keeping the number of ‘poor-smelling ants’ constant during Monte Carlo simulations. (paper)

  2. Ant-mediated effects on spruce litter decomposition, solution chemistry, and microbial activity

    DEFF Research Database (Denmark)

    Stadler, B.; Schramm, Andreas; Kalbitz, K.

    2006-01-01

    the effects of ants and aphid honeydew on litter solution of Norway spruce, microbial enzyme activities, and needle decomposition in a field and greenhouse experiment during summer 2003. In the field, low ant densities had relatively little effects on litter solution 30 cm away from a tree trunk...... and %N were not affected by ants or honeydew. Our results suggest that ants have a distinct and immediate effect on solution composition and microbial activity in the litter layer indicating accelerated litter decay whereas the effect of honeydew was insignificant. Keywords: Ants; Decomposition; Formica......Forest management practices often generate clear-cut patches, which may be colonized by ants not present in the same densities in mature forests. In addition to the associated changes in abiotic conditions ants can initiate processes, which do not occur in old-growth stands. Here, we analyse...

  3. Absence of jamming in ant trails: feedback control of self-propulsion and noise.

    Science.gov (United States)

    Chaudhuri, Debasish; Nagar, Apoorva

    2015-01-01

    We present a model of ant traffic considering individual ants as self-propelled particles undergoing single-file motion on a one-dimensional trail. Recent experiments on unidirectional ant traffic in well-formed natural trails showed that the collective velocity of ants remains approximately unchanged, leading to the absence of jamming even at very high densities [John et al., Phys. Rev. Lett. 102, 108001 (2009)]. Assuming a feedback control mechanism of self-propulsion force generated by each ant using information about the distance from the ant in front, our model captures all the main features observed in the experiment. The distance headway distribution shows a maximum corresponding to separations within clusters. The position of this maximum remains independent of average number density. We find a non-equilibrium first-order transition, with the formation of an infinite cluster at a threshold density where all the ants in the system suddenly become part of a single cluster.

  4. Norma percibida de consumo de marihuana en los pares de estudiantes universitarios Norma percebida de consumo de maconha sobre os pares de estudantes universitários Perceived norm for marijuana use among university student peers

    Directory of Open Access Journals (Sweden)

    Angélica Cazenave

    2009-01-01

    Full Text Available En este estudio se describe la relación entre la norma percibida del consumo de marihuana en los pares y el consumo real informado por alumnos de una universidad chilena. Se trata de un estudio cuantitativo, multicéntrico y transversal. Participaron 449 estudiantes previa firma del consentimiento informado. La información se recolectó con un cuestionario autoaplicado y se analizó con el programa SPSS 15.0. Fue encontrado que la mayoría son mujeres solteras, entre 20 y 21 años de edad, estudiantes de enfermería y educación. La norma percibida fue mayor que la de estudios nacionales (32,1% versus 21%; también el consumo autoinformado fue mayor que el nacional (32,1% versus 5,6%. Se observa un mayor consumo entre las mujeres, en educación y enfermería. Se confirma la feminización del consumo; el inicio del consumo en la universidad, el uso recreativo y la mayor tolerancia al consumo en los pares. Existe una sobreestimación del consumo de marihuana, lo que de acuerdo a la Teoría de las Normas Sociales y de Normalización influye en el aumento del consumo. Esta investigación constituye un aporte a las políticas de la salud del país y de la universidad.Descreve-se, aqui, a relação entre norma percebida de consumo de maconha entre os pares e consumo reportado em alunos de uma universidade chilena. Este é um estudo quantitativo, multicêntrico, transversal. Participaram 449 estudantes, com livre consentimento. As informações foram coletadas mediante questionário autoaplicado e analisadas através do programa SPSS 15.0. RESULTADOS: a maioria são mulheres, solteiras, entre 20 e 21 anos, estudantes de enfermagem e educação. A norma percebida é maior do que nos estudos nacionais (32,1% vs 21% e maior do que o consumo autorreportado (32,1% vs 5,6%. Observa-se maior consumo nas mulheres, e dos cursos de educação e de enfermagem. Confirma-se a feminização do consumo, o qual se inicia na universidade, por uso recreativo, e haver

  5. Temporal Variation in the Abundance and Richness of Foliage-Dwelling Ants Mediated by Extrafloral Nectar.

    Science.gov (United States)

    Belchior, Ceres; Sendoya, Sebastián F; Del-Claro, Kleber

    2016-01-01

    Plants bearing extrafloral nectaries (EFNs) are common in the Brazilian cerrado savanna, where climatic conditions having marked seasonality influence arboreal ant fauna organization. These ant-plant interactions have rarely been studied at community level. Here, we tested whether: 1) EFN-bearing plants are more visited by ants than EFN-lacking plants; 2) ant visitation is higher in the rainy season than in dry season; 3) plants producing young leaves are more visited than those lacking young leaves in the rainy season; 4) during the dry season, plants with old leaves and flowers are more visited than plants with young leaves and bare of leaves or flowers; 5) the composition of visiting ant fauna differs between plants with and without EFNs. Field work was done in a cerrado reserve near Uberlândia, MG State, Brazil, along ten transects (total area 3,000 m2), in the rainy (October-January) and dry seasons (April-July) of 2010-2011. Plants (72 species; 762 individuals) were checked three times per season for ant presence. Results showed that 21 species (29%) and 266 individuals (35%) possessed EFNs. These plants attracted 38 ant species (36 in rainy, 26 in dry season). In the rainy season, plants with EFNs had higher ant abundance/richness than plants without EFNs, but in the dry season, EFN presence did not influence ant visitation. Plant phenology affected ant richness and abundance in different ways: plants with young leaves possessed higher ant richness in the rainy season, but in the dry season ant abundance was higher on plants possessing old leaves or flowers. The species composition of plant-associated ant communities, however, did not differ between plants with and without EFNs in either season. These findings suggest that the effect of EFN presence on a community of plant-visiting ants is context dependent, being conditioned to seasonal variation.

  6. Species diversity and distribution patterns of the ants of Amazonian Ecuador.

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    Kari T Ryder Wilkie

    2010-10-01

    Full Text Available Ants are among the most diverse, abundant and ecologically significant organisms on earth. Although their species richness appears to be greatest in the New World tropics, global patterns of ant diversity and distribution are not well understood. We comprehensively surveyed ant diversity in a lowland primary rainforest in Western Amazonia, Ecuador using canopy fogging, pitfall traps, baits, hand collecting, mini-Winkler devices and subterranean probes to sample ants. A total of 489 ant species comprising 64 genera in nine subfamilies were identified from samples collected in only 0.16 square kilometers. The most species-rich genera were Camponotus, Pheidole, Pseudomyrmex, Pachycondyla, Brachymyrmex, and Crematogaster. Camponotus and Pseudomyrmex were most diverse in the canopy, while Pheidole was most diverse on the ground. The three most abundant ground-dwelling ant genera were Pheidole, Solenopsis and Pyramica. Crematogaster carinata was the most abundant ant species in the canopy; Wasmannia auropunctata was most abundant on the ground, and the army ant Labidus coecus was the most abundant subterranean species. Ant species composition among strata was significantly different: 80% of species were found in only one stratum, 17% in two strata, and 3% in all three strata. Elevation and the number of logs and twigs available as nest sites were significant predictors of ground-dwelling ant species richness. Canopy species richness was not correlated with any ecological variable measured. Subterranean species richness was negatively correlated with depth in the soil. When ant species were categorized using a functional group matrix based on diet, nest-site preference and foraging ecology, the greatest diversity was found in Omnivorous Canopy Nesters. Our study indicates ant species richness is exceptionally high at Tiputini. We project 647-736 ant species in this global hotspot of biodiversity. Considering the relatively small area surveyed, this

  7. Temporal Variation in the Abundance and Richness of Foliage-Dwelling Ants Mediated by Extrafloral Nectar.

    Directory of Open Access Journals (Sweden)

    Ceres Belchior

    Full Text Available Plants bearing extrafloral nectaries (EFNs are common in the Brazilian cerrado savanna, where climatic conditions having marked seasonality influence arboreal ant fauna organization. These ant-plant interactions have rarely been studied at community level. Here, we tested whether: 1 EFN-bearing plants are more visited by ants than EFN-lacking plants; 2 ant visitation is higher in the rainy season than in dry season; 3 plants producing young leaves are more visited than those lacking young leaves in the rainy season; 4 during the dry season, plants with old leaves and flowers are more visited than plants with young leaves and bare of leaves or flowers; 5 the composition of visiting ant fauna differs between plants with and without EFNs. Field work was done in a cerrado reserve near Uberlândia, MG State, Brazil, along ten transects (total area 3,000 m2, in the rainy (October-January and dry seasons (April-July of 2010-2011. Plants (72 species; 762 individuals were checked three times per season for ant presence. Results showed that 21 species (29% and 266 individuals (35% possessed EFNs. These plants attracted 38 ant species (36 in rainy, 26 in dry season. In the rainy season, plants with EFNs had higher ant abundance/richness than plants without EFNs, but in the dry season, EFN presence did not influence ant visitation. Plant phenology affected ant richness and abundance in different ways: plants with young leaves possessed higher ant richness in the rainy season, but in the dry season ant abundance was higher on plants possessing old leaves or flowers. The species composition of plant-associated ant communities, however, did not differ between plants with and without EFNs in either season. These findings suggest that the effect of EFN presence on a community of plant-visiting ants is context dependent, being conditioned to seasonal variation.

  8. Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants

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    Alessandro Ossola

    2015-10-01

    Full Text Available Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i ant abundance and species richness would be higher in high-complexity urban habitats, (ii ant assemblages would differ between low- and high-complexity habitats and (iii ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size.

  9. Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants

    Science.gov (United States)

    Nash, Michael A.; Christie, Fiona J.; Hahs, Amy K.; Livesley, Stephen J.

    2015-01-01

    Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size. PMID:26528416

  10. Ant-plant-homopteran mutualism: how the third partner affects the interaction between a plant-specialist ant and its myrmecophyte host

    Science.gov (United States)

    Gaume, L.; McKey, D.; Terrin, S.

    1998-01-01

    By estimating relative costs and benefits, we explored the role of the homopteran partner in the protection mutualism between the myrmecophyte Leonardoxa africana T3, the ant Aphomomyrmex afer, and sap-sucking homopterans tended by ants in the tree's swollen hollow twigs. The ants obtain nest sites and food from their host-plant (food is obtained either directly by extrafloral nectar or indirectly via homopterans). Aphomomyrmex workers patrol the young leaves of L. africana T3 and protect them against phytophagous insects. Because ants tended, either solely or primarily, coccids in some trees and pseudococcids in others, we were able to study whether the nature of the interaction was dependent on the identity of the third partner. First, the type of homopteran affects the benefits to the tree of maintaining a large ant colony. Larger colony size (relative to tree size) confers greater protection against herbivory; this relationship is more pronounced for trees whose ants tend pseudococcids than for those in which ants tend coccids. Second, for trees (and associated ant colonies) of comparable size, homopteran biomass was much larger in trees harbouring coccids than in trees with pseudococcids. Thus, the cost to the tree of maintaining ants may be greater when ants are associated with coccids. The net benefits to the plant of maintaining ants appear to be much greater with pseudococcids as the third partner. To explore how the type of homopteran affects functioning of the system, we attempted to determine which of the resources (nest sites, extrafloral nectar, and homopterans) is likely to limit ant colony size. In trees where ants tended coccids, ant-colony biomass was strongly dependent on the number of extrafloral nectaries. In contrast, in trees whose ants tended only pseudococcids, colony biomass was not related to the number of nectaries and was most strongly determined by the volume of available nest sites. We present hypotheses to explain how the type of

  11. Arboreal ant colonies as 'hot-points' of cryptic diversity for myrmecophiles: the weaver ant Camponotus sp. aff. textor and its interaction network with its associates.

    Directory of Open Access Journals (Sweden)

    Gabriela Pérez-Lachaud

    Full Text Available INTRODUCTION: Systematic surveys of macrofaunal diversity within ant colonies are lacking, particularly for ants nesting in microhabitats that are difficult to sample. Species associated with ants are generally small and rarely collected organisms, which makes them more likely to be unnoticed. We assumed that this tendency is greater for arthropod communities in microhabitats with low accessibility, such as those found in the nests of arboreal ants that may constitute a source of cryptic biodiversity. MATERIALS AND METHODS: We investigated the invertebrate diversity associated with an undescribed, but already threatened, Neotropical Camponotus weaver ant. As most of the common sampling methods used in studies of ant diversity are not suited for evaluating myrmecophile diversity within ant nests, we evaluated the macrofauna within ant nests through exhaustive colony sampling of three nests and examination of more than 80,000 individuals. RESULTS: We identified invertebrates from three classes belonging to 18 taxa, some of which were new to science, and recorded the first instance of the co-occurrence of two brood parasitoid wasp families attacking the same ant host colony. This diversity of ant associates corresponded to a highly complex interaction network. Agonistic interactions prevailed, but the prevalence of myrmecophiles was remarkably low. CONCLUSIONS: Our data support the hypothesis of the evolution of low virulence in a variety of symbionts associated with large insect societies. Because most myrmecophiles found in this work are rare, strictly specific, and exhibit highly specialized biology, the risk of extinction for these hitherto unknown invertebrates and their natural enemies is high. The cryptic, far unappreciated diversity within arboreal ant nests in areas at high risk of habitat loss qualifies these nests as 'hot-points' of biodiversity that urgently require special attention as a component of conservation and management

  12. Arboreal ant colonies as 'hot-points' of cryptic diversity for myrmecophiles: the weaver ant Camponotus sp. aff. textor and its interaction network with its associates.

    Science.gov (United States)

    Pérez-Lachaud, Gabriela; Lachaud, Jean-Paul

    2014-01-01

    Systematic surveys of macrofaunal diversity within ant colonies are lacking, particularly for ants nesting in microhabitats that are difficult to sample. Species associated with ants are generally small and rarely collected organisms, which makes them more likely to be unnoticed. We assumed that this tendency is greater for arthropod communities in microhabitats with low accessibility, such as those found in the nests of arboreal ants that may constitute a source of cryptic biodiversity. We investigated the invertebrate diversity associated with an undescribed, but already threatened, Neotropical Camponotus weaver ant. As most of the common sampling methods used in studies of ant diversity are not suited for evaluating myrmecophile diversity within ant nests, we evaluated the macrofauna within ant nests through exhaustive colony sampling of three nests and examination of more than 80,000 individuals. We identified invertebrates from three classes belonging to 18 taxa, some of which were new to science, and recorded the first instance of the co-occurrence of two brood parasitoid wasp families attacking the same ant host colony. This diversity of ant associates corresponded to a highly complex interaction network. Agonistic interactions prevailed, but the prevalence of myrmecophiles was remarkably low. Our data support the hypothesis of the evolution of low virulence in a variety of symbionts associated with large insect societies. Because most myrmecophiles found in this work are rare, strictly specific, and exhibit highly specialized biology, the risk of extinction for these hitherto unknown invertebrates and their natural enemies is high. The cryptic, far unappreciated diversity within arboreal ant nests in areas at high risk of habitat loss qualifies these nests as 'hot-points' of biodiversity that urgently require special attention as a component of conservation and management programs.

  13. Arboreal Ant Colonies as ‘Hot-Points’ of Cryptic Diversity for Myrmecophiles: The Weaver Ant Camponotus sp. aff. textor and Its Interaction Network with Its Associates

    Science.gov (United States)

    Pérez-Lachaud, Gabriela; Lachaud, Jean-Paul

    2014-01-01

    Introduction Systematic surveys of macrofaunal diversity within ant colonies are lacking, particularly for ants nesting in microhabitats that are difficult to sample. Species associated with ants are generally small and rarely collected organisms, which makes them more likely to be unnoticed. We assumed that this tendency is greater for arthropod communities in microhabitats with low accessibility, such as those found in the nests of arboreal ants that may constitute a source of cryptic biodiversity. Materials and Methods We investigated the invertebrate diversity associated with an undescribed, but already threatened, Neotropical Camponotus weaver ant. As most of the common sampling methods used in studies of ant diversity are not suited for evaluating myrmecophile diversity within ant nests, we evaluated the macrofauna within ant nests through exhaustive colony sampling of three nests and examination of more than 80,000 individuals. Results We identified invertebrates from three classes belonging to 18 taxa, some of which were new to science, and recorded the first instance of the co-occurrence of two brood parasitoid wasp families attacking the same ant host colony. This diversity of ant associates corresponded to a highly complex interaction network. Agonistic interactions prevailed, but the prevalence of myrmecophiles was remarkably low. Conclusions Our data support the hypothesis of the evolution of low virulence in a variety of symbionts associated with large insect societies. Because most myrmecophiles found in this work are rare, strictly specific, and exhibit highly specialized biology, the risk of extinction for these hitherto unknown invertebrates and their natural enemies is high. The cryptic, far unappreciated diversity within arboreal ant nests in areas at high risk of habitat loss qualifies these nests as ‘hot-points’ of biodiversity that urgently require special attention as a component of conservation and management programs. PMID:24941047

  14. Phengaris (Maculinea) teleius butterflies select host plants close to Myrmica ants for oviposition, but P. nausithous do not

    NARCIS (Netherlands)

    Wynhoff, Irma; Langevelde, van Frank

    2017-01-01

    Many lycaenid butterfly species have interactions with ants, with 12% obligatorily depending on two sequential sources of larval food, namely host plants and host ants. When host plants are abundant but the density of host ant nests is relatively low, most host plants have no host ant nest in their

  15. Actitudes europeos ante el envejecimiento y los personas mayores

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    ALAN WALKER

    1996-01-01

    Full Text Available n este artículo se realiza un análisis comparativo de las actitudes ante el envejecimiento y las personas mayores en los doce estados miembros de la unión europea. Está basado en datos originales de encuesta y se centra en la relación entre las personas mayores y los jovenes, la jubilación y las pensiones, los trabajadores de edad y el empleo, la atención social a las personas mayores y la política de la vejez. Por lo tanto, el artículo intenta proporcionar un resumen de las principales dimensiones de las actitudes publicas ante el envejecimiento en la union europea.

  16. Multi-objective ant algorithm for wireless sensor network positioning

    International Nuclear Information System (INIS)

    Fidanova, S.; Shindarov, M.; Marinov, P.

    2013-01-01

    It is impossible to imagine our modern life without telecommunications. Wireless networks are a part of telecommunications. Wireless sensor networks (WSN) consist of spatially distributed sensors, which communicate in wireless way. This network monitors physical or environmental conditions. The objective is the full coverage of the monitoring region and less energy consumption of the network. The most appropriate approach to solve the problem is metaheuristics. In this paper the full coverage of the area is treated as a constrain. The objectives which are optimized are a minimal number of sensors and energy (lifetime) of the network. We apply multi-objective Ant Colony Optimization to solve this important telecommunication problem. We chose MAX-MIN Ant System approach, because it is proven to converge to the global optima

  17. Sexual Cooperation: Mating Increases Longevity in Ant Queens

    DEFF Research Database (Denmark)

    Schrempf, Alexandra; Heinze, Jürgen; Cremer, Sylvia

    2005-01-01

    Divergent reproductive interests of males and females often cause sexual conflict [1] and [2] . Males of many species manipulate females by transferring seminal fluids that boost female short-term fecundity while decreasing their life expectancy and future reproductivity [3] and [4] . The life...... history of ants, however, is expected to reduce sexual conflict; whereas most insect females show repeated phases of mating and reproduction, ant queens mate only during a short period early in life and undergo a lifelong commitment to their mates by storing sperm [5] . Furthermore, sexual offspring can...... sterilized male lived considerably longer and started laying eggs earlier than virgin queens. Only queens that received viable sperm from fertile males showed increased fecundity. The lack of a trade-off between fecundity and longevity is unexpected, given evolutionary theories of aging [6] . Our data...

  18. The Müller-Lyer illusion in ant foraging.

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    Tomoko Sakiyama

    Full Text Available The Müller-Lyer illusion is a classical geometric illusion in which the apparent (perceived length of a line depends on whether the line terminates in an arrow tail or arrowhead. This effect may be caused by economic compensation for the gap between the physical stimulus and visual fields. Here, we show that the Müller-Lyer illusion can also be produced by the foraging patterns of garden ants (Lasius niger and that the pattern obtained can be explained by a simple, asynchronously updated foraging ant model. Our results suggest that the geometric illusion may be a byproduct of the foraging process, in which local interactions underlying efficient exploitation can also give rise to global exploration, and that visual information processing in human could implement similar modulation between local efficient processing and widespread computation.

  19. Evolutionarily advanced ant farmers rear polyploid fungal crops

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Aanen, D.K.; Schiøtt, Morten

    2015-01-01

    to be lowly and facultatively polyploid (just over two haplotypes on average), whereas Atta and Acromyrmex symbionts are highly and obligatorily polyploid (ca. 5-7 haplotypes on average). This stepwise transition appears analogous to ploidy variation in plants and fungi domesticated by humans and in fungi...... the number of nuclei per fungal cell for 42 symbionts reared by 14 species of Panamanian fungus-growing ants. This showed that domesticated symbionts of higher attine ants are polykaryotic with 7-17 nuclei per cell, whereas nonspecialized crops of lower attines are dikaryotic similar to most free...... domesticated by termites and plants, where gene or genome duplications were typically associated with selection for higher productivity, but allopolyploid chimerism was incompatible with sexual reproduction....

  20. Study on bi-directional pedestrian movement using ant algorithms

    International Nuclear Information System (INIS)

    Gokce, Sibel; Kayacan, Ozhan

    2016-01-01

    A cellular automata model is proposed to simulate bi-directional pedestrian flow. Pedestrian movement is investigated by using ant algorithms. Ants communicate with each other by dropping a chemical, called a pheromone, on the substrate while crawling forward. Similarly, it is considered that oppositely moving pedestrians drop ‘visual pheromones’ on their way and the visual pheromones might cause attractive or repulsive interactions. This pheromenon is introduced into modelling the pedestrians’ walking preference. In this way, the decision-making process of pedestrians will be based on ‘the instinct of following’. At some densities, the relationships of velocity–density and flux–density are analyzed for different evaporation rates of visual pheromones. Lane formation and phase transition are observed for certain evaporation rates of visual pheromones. (paper)