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Sample records for ante dilemas sociales

  1. DARWIN Y LOS DILEMAS SOCIALES

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    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.

  2. DILEMAS MORALES

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    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. ...

  3. El nuevo dilema de la izquierda: identidad vs justicia social

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    José María Seco Martínez

    2011-06-01

    Full Text Available ResumenLa izquierda carece en la actualidad de iniciativa real. Desde la caída del muro se vio ampliamente desbordada por el neocapitalismo. La idea de justicia social dejaba entonces de tener valor. Desde entonces los partidos de izquierda no asumen posiciones diáfanas en este sentido. No reivindican la justicia social y son ambiguos frente a las condiciones que impone el capitalismo. Sitúan el eje de sus discurso político en cuestiones más relacionadas con la identidad, que con la justicia social y la clase social. De la respuesta a la pregunta ¿sigue siendo hoy una prioridad para la izquierda la búsqueda de la justicia social?, dependerá en buena medida la razón de su existencia. Abstract Nowadays the left lacks initiative. Since the fall of the Berlin Wall it was widely exceded by neocapitalism. At that time the idea of social justice had no longer any importance. Since then the left parties did not take up a strong stance, they do not demand social justice and they are ambiguous  facing the conditions imponed by capitalism. They focus their political programme mainly on identity more than  social justice and social class. Their raison d´être will depend to a great extent on the way they can answer the question, is it still today a priority for the left the search for social justice?

  4. El nuevo dilema de la izquierda: identidad vs justicia social

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    José María Seco Martínez

    2011-06-01

    Full Text Available Resumen La izquierda carece en la actualidad de iniciativa real. Desde la caída del muro se vio ampliamente desbordada por el neocapitalismo. La idea de justicia social dejaba entonces de tener valor. Desde entonces los partidos de izquierda no asumen posiciones diáfanas en este sentido. No reivindican la justicia social y son ambiguos frente a las condiciones que impone el capitalismo. Sitúan el eje de sus discurso político en cuestiones más relacionadas con la identidad, que con la justicia social y la clase social. De la respuesta a la pregunta ¿sigue siendo hoy una prioridad para la izquierda la búsqueda de la justicia social?, dependerá en buena medida la razón de su existencia.   Abstract Nowadays the left lacks initiative. Since the fall of the Berlin Wall it was widely exceded by neocapitalism. At that time the idea of social justice had no longer any importance. Since then the left parties did not take up a strong stance, they do not demand social justice and they are ambiguous  facing the conditions imponed by capitalism. They focus their political programme mainly on identity more than  social justice and social class. Their raison d´être will depend to a great extent on the way they can answer the question, is it still today a priority for the left the search for social justice?

  5. 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....

  6. Recognition of social identity in ants

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    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...

  7. Recognition of social identity in ants

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    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.

  8. Recognition in ants: social origin matters.

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    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.

  9. 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.

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

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    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.

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

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    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.

  12. 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.

  13. 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. 

  14. La dicotomía cuantitativo/cualitativo: falsos dilemas en investigación social

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    María Celina Chavarría-González

    2011-01-01

    Se discute la dicotomía cuantitativo/cualitativo desde la perspectiva de paradigmas, con el fin de contribuir a un cuestionamiento más amplio que aporte a la reflexión sobre el abordaje de teoría y método en los planteamientos y en la enseñanza de la indagación social. Se destacan supuestos implícitos en diferentes versiones de paradigma, retomándose la necesidad de rebasar concepciones dicotómicas, señalando la visión preclara de Vygotski al respecto. Se recurre a la dimensión histórico-cult...

  15. Utilitarismos ou equidade? Dilemas éticos na política social e ambiental

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    Margarida Queirós

    2000-12-01

    Full Text Available UTILITARIANISM OR EQUITY? DILEMMAS FOR ENVIRONMENT AND LAND USE. The aim of this note is to stimulate discussion as to the criteria behind land use planning and the distribution of natural resources to achieve a sense of social well-being. When determining strategies on how to use these resources and other environmental services, considerations involving efficiency versus equity reveal value choices and contradictory opinions that we seek to question. Numerousexamples demonstrate that certain economic policy choices which affect environment and land planning are responsible for the emergence of predicaments known as the ‘prisoner’s dilemma’ and the ‘tragedy of the commons’. ‘No free lunch’ belongs to a group of conservation laws that steers towards the painful awareness that traditional economic policy has still severe limitations.

  16. La dicotomía cuantitativo/cualitativo: falsos dilemas en investigación social

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    María Celina Chavarría-González

    2011-01-01

    Full Text Available Se discute la dicotomía cuantitativo/cualitativo desde la perspectiva de paradigmas, con el fin de contribuir a un cuestionamiento más amplio que aporte a la reflexión sobre el abordaje de teoría y método en los planteamientos y en la enseñanza de la indagación social. Se destacan supuestos implícitos en diferentes versiones de paradigma, retomándose la necesidad de rebasar concepciones dicotómicas, señalando la visión preclara de Vygotski al respecto. Se recurre a la dimensión histórico-cultural y desde la complejidad como aquella que permite abordar la concepción paradigmática como producto de la consciencia y del sentido, como cosmovisión y práctica histórica y políticamente situada: el ser humano, al construir y reconstruir su mundo, se reconstruye históricamente a sí mismo. Se aboga por una clarificación epistemológica que rebase la concepción hacia métodos mixtos, reconociendo como confuso religar aquello que no está desligado.

  17. Social context predicts recognition systems in ant queens

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    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...

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

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    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.

  19. 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.

  20. The genomic impact of 100 million years of social evolution in seven ant species

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    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...

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

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    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.

  2. Exploitation Strategies in Social Parasites of Fungus Growing Ants

    DEFF Research Database (Denmark)

    Clement, Janni Dolby

    One of the most remarkable and complex parasitic interactions is social parasitism, where a parasite exploits a complete society, rather than an individual organism. By integrating into a society the parasite gains protection against predators and diseases, and can redirect resources from the host...... to increase its own fitness. The host will use a sophisticated recognition system in order to accept nestmates and expel intruders from their societies. However this defence barrier can be overcome by parasites. Among the most specialized social parasites are the inquilines that exploit social insect colonies...... to this are Acromyrmex insinuator and Acromyrmex ameliae, parasites of fungus-growing ants. By still producing a worker caste both species offers a rare opportunity to study adaptive features in parasite worker behaviour. Furthermore can closely related inquiline-host combinations give us an insight in the trade...

  3. Social coercion of larval development in an ant species.

    Science.gov (United States)

    Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

    2016-04-01

    Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

  4. Social coercion of larval development in an ant species

    Science.gov (United States)

    Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

    2016-04-01

    Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

  5. ¿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.

  6. Estado social de derecho o estado de opinión: dilema sin resolver en América Latina

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    Orlando José Cadrazco Salcedo

    2010-01-01

    Full Text Available Resumen:El alcance del Estado Social de Derecho no se circunscribe solamente a su terminología ni a lo etimológico desu traducción, todo por el contrario se da en las relaciones que deben marcar el comportamiento del Estado frentea los conciudadanos que lo integran y se refuerza con el principio de la Dignidad Humana, lo que había venidosiendo tratado desde la Revolución Francesa pero que ahora cobra mayor vigencia, dada la alta concentracióndel garantismo que sobre los derechos de los individuos deben preservar los Estados frente al conglomeradosocial. En el Estado de Opinión si bien existen unas normas, estas se van acomodando diariamente según elquerer del Gobernante de turno y lo que prima no es el apego o cumplimiento de las normas, sino la manipulaciónque el o los Gobernantes de turno hacen de la opinión pública a través de los medios masivos de comunicacióny el manejo de las encuestas de opinión que sirven para catapultar o enterrar un gobernante o un período deGobierno en un estado determinado.Palabras Claves:Estado Social de Derecho, Estado de Opinión, Gobierno, Democracia, Constitución, Población, Encuestas,Medios de Comunicación, Derechos Sociales.Abstract:The scope of the rule of law is not limited to terminology or the etymology of its translation, on the contrary,everything is in relationships that should mark the conduct of the State against the citizens in it and is strengthenedby the principles of human dignity, which had been treated since the French Revolution, but now becomes moreeffective, given the high concentration of the guarantors of the rights of individuals to preserve the front of thesocial conglomerate. In the state of opinion, although there are rules, they will want to accommodate the daily asthe ruler of the day and what the attachment is no premium or compliance, but the handling or the rulers of themake-shift public opinion through the mass media and the handling of the polls used to bury a

  7. Dilemas y tensiones en torno al Trabajo Social en ciudad de La Plata en los primeros setenta

    OpenAIRE

    Arrúa, Néstor Nicolás

    2016-01-01

    En este trabajo buscaremos dar cuenta de los debates intelectuales y tensiones políticas en torno al Trabajo Social en los espacios de formación profesional de gestión pública en tiempos de una acelerada politización de sectores juveniles de las clases medias. Nos hemos circunscrito a los debates intelectuales en relación a los significados de la disciplina, en torno a los intentos de presentar una definición y moviliza fuerzas y tensiones en los distintos colectivos profesionales. Abordaremo...

  8. EL CIRCO Y MI DILEMA

    Directory of Open Access Journals (Sweden)

    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

  9. Edge Effects on Community and Social Structure of Northern Temperate Deciduous Forest Ants

    Directory of Open Access Journals (Sweden)

    Valerie S. Banschbach

    2012-01-01

    Full Text Available Determining how ant communities are impacted by challenges from habitat fragmentation, such as edge effects, will help us understand how ants may be used as a bioindicator taxon. To assess the impacts of edge effects upon the ant community in a northern temperate deciduous forest, we studied edge and interior sites in Jericho, VT, USA. The edges we focused upon were created by recreational trails. We censused the ants at these sites for two consecutive growing seasons using pitfall traps and litter plot excavations. We also collected nests of the most common ant species at our study sites, Aphaenogaster rudis, for study of colony demography. Significantly greater total numbers of ants and ant nests were found in the edge sites compared to the interior sites but rarefaction analysis showed no significant difference in species richness. Aphaenogaster rudis was the numerically dominant ant in the habitats sampled but had a greater relative abundance in the interior sites than in the edge sites both in pitfall and litter plot data. Queen number of A. rudis significantly differed between the nests collected in the edge versus the interior sites. Habitat-dependent changes in social structure of ants represent another possible indicator of ecosystem health.

  10. Adaptive Radiation in Socially Advanced Stem-Group Ants from the Cretaceous.

    Science.gov (United States)

    Barden, Phillip; Grimaldi, David A

    2016-02-22

    Across terrestrial ecosystems, modern ants are ubiquitous. As many as 94 out of every 100 individual arthropods in rainforests are ants, and they constitute up to 15% of animal biomass in the Amazon. Moreover, ants are pervasive agents of natural selection as over 10,000 arthropod species are specialized inquilines or myrmecomorphs living among ants or defending themselves through mimicry. Such impact is traditionally explained by sociality: ants are the first major group of ground-dwelling predatory insects to become eusocial, increasing efficiency of tasks and establishing competitive superiority over solitary species. A wealth of specimens from rich deposits of 99 million-year-old Burmese amber resolves ambiguity regarding sociality and diversity in the earliest ants. The stem-group genus Gerontoformica maintained distinct reproductive castes including morphotypes unknown in solitary aculeate (stinging) wasps, providing insight into early behavior. We present rare aggregations of workers, indicating group recruitment as well as an instance of interspecific combat; such aggression is a social feature of modern ants. Two species and an unusual new genus are described, further expanding the remarkable diversity of early ants. Stem-group ants are recovered as a paraphyletic assemblage at the base of modern lineages varying greatly in size, form, and mouthpart structure, interpreted here as an adaptive radiation. Though Cretaceous stem-group ants were eusocial and adaptively diverse, we hypothesize that their extinction resulted from the rise of competitively superior crown-group taxa that today form massive colonies, consistent with Wilson and Hölldobler's concept of "dynastic succession." Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. External immunity in ant societies: sociality and colony size do not predict investment in antimicrobials

    Science.gov (United States)

    Halawani, Omar; Pearson, Bria; Mathews, Stephanie; López-Uribe, Margarita M.; Dunn, Robert R.; Smith, Adrian A.

    2018-01-01

    Social insects live in dense groups with a high probability of disease transmission and have therefore faced strong pressures to develop defences against pathogens. For this reason, social insects have been hypothesized to invest in antimicrobial secretions as a mechanism of external immunity to prevent the spread of disease. However, empirical studies linking the evolution of sociality with increased investment in antimicrobials have been relatively few. Here we quantify the strength of antimicrobial secretions among 20 ant species that cover a broad spectrum of ant diversity and colony sizes. We extracted external compounds from ant workers to test whether they inhibited the growth of the bacterium Staphylococcus epidermidis. Because all ant species are highly social, we predicted that all species would exhibit some antimicrobial activity and that species that form the largest colonies would exhibit the strongest antimicrobial response. Our comparative approach revealed that strong surface antimicrobials are common to particular ant clades, but 40% of species exhibited no antimicrobial activity at all. We also found no correlation between antimicrobial activity and colony size. Rather than relying on antimicrobial secretions as external immunity to control pathogen spread, many ant species have probably developed alternative strategies to defend against disease pressure. PMID:29515850

  12. An Engineered orco Mutation Produces Aberrant Social Behavior and Defective Neural Development in Ants.

    Science.gov (United States)

    Yan, Hua; Opachaloemphan, Comzit; Mancini, Giacomo; Yang, Huan; Gallitto, Matthew; Mlejnek, Jakub; Leibholz, Alexandra; Haight, Kevin; Ghaninia, Majid; Huo, Lucy; Perry, Michael; Slone, Jesse; Zhou, Xiaofan; Traficante, Maria; Penick, Clint A; Dolezal, Kelly; Gokhale, Kaustubh; Stevens, Kelsey; Fetter-Pruneda, Ingrid; Bonasio, Roberto; Zwiebel, Laurence J; Berger, Shelley L; Liebig, Jürgen; Reinberg, Danny; Desplan, Claude

    2017-08-10

    Ants exhibit cooperative behaviors and advanced forms of sociality that depend on pheromone-mediated communication. Odorant receptor neurons (ORNs) express specific odorant receptors (ORs) encoded by a dramatically expanded gene family in ants. In most eusocial insects, only the queen can transmit genetic information, restricting genetic studies. In contrast, workers in Harpegnathos saltator ants can be converted into gamergates (pseudoqueens) that can found entire colonies. This feature facilitated CRISPR-Cas9 generation of germline mutations in orco, the gene that encodes the obligate co-receptor of all ORs. orco mutations should significantly impact olfaction. We demonstrate striking functions of Orco in odorant perception, reproductive physiology, and social behavior plasticity. Surprisingly, unlike in other insects, loss of OR functionality also dramatically impairs development of the antennal lobe to which ORNs project. Therefore, the development of genetics in Harpegnathos establishes this ant species as a model organism to study the complexity of eusociality. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. A Y-like social chromosome causes alternative colony organization in fire ants

    Science.gov (United States)

    Intraspecific variability in social organization is common, yet the underlying causes are rarely known1-3. In the fire ant Solenopsis invicta, the existence of two divergent forms of social organisation is under the control of a single Mendelian genomic element marked by two variants of an odorant b...

  14. Bacterial symbiont sharing in Megalomyrmex social parasites and their fungus-growing ant hosts

    DEFF Research Database (Denmark)

    Liberti, Joanito; Sapountzis, Panagiotis; Hansen, Lars H.

    2015-01-01

    nests such as consumption of the same fungus garden food, eating of host brood by social parasites, trophallaxis and grooming interactions between the ants, or parallel acquisition from the same nest environment. Our results imply that cohabiting ant social parasites and hosts may obtain functional...... benefits from bacterial symbiont transfer even when they are not closely related....

  15. Discovery of defense- and neuropeptides in social ants by genome-mining.

    Directory of Open Access Journals (Sweden)

    Christian W Gruber

    Full Text Available Natural peptides of great number and diversity occur in all organisms, but analyzing their peptidome is often difficult. With natural product drug discovery in mind, we devised a genome-mining approach to identify defense- and neuropeptides in the genomes of social ants from Atta cephalotes (leaf-cutter ant, Camponotus floridanus (carpenter ant and Harpegnathos saltator (basal genus. Numerous peptide-encoding genes of defense peptides, in particular defensins, and neuropeptides or regulatory peptide hormones, such as allatostatins and tachykinins, were identified and analyzed. Most interestingly we annotated genes that encode oxytocin/vasopressin-related peptides (inotocins and their putative receptors. This is the first piece of evidence for the existence of this nonapeptide hormone system in ants (Formicidae and supports recent findings in Tribolium castaneum (red flour beetle and Nasonia vitripennis (parasitoid wasp, and therefore its confinement to some basal holometabolous insects. By contrast, the absence of the inotocin hormone system in Apis mellifera (honeybee, another closely-related member of the eusocial Hymenoptera clade, establishes the basis for future studies on the molecular evolution and physiological function of oxytocin/vasopressin-related peptides (vasotocin nonapeptide family and their receptors in social insects. Particularly the identification of ant inotocin and defensin peptide sequences will provide a basis for future pharmacological characterization in the quest for potent and selective lead compounds of therapeutic value.

  16. Social prophylaxis: group interaction promotes collective immunity in ant colonies

    DEFF Research Database (Denmark)

    Ugelvig, Line V; Cremer, Sylvia

    2007-01-01

    Life in a social group increases the risk of disease transmission. To counteract this threat, social insects have evolved manifold antiparasite defenses, ranging from social exclusion of infected group members to intensive care. It is generally assumed that individuals performing hygienic behavio...

  17. El periodista, ante la espiral de silencio

    Directory of Open Access Journals (Sweden)

    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.

  18. Ante-projeto "Memória Social Paulista"

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    Jaelson Bitran Trindade

    1977-09-01

    Full Text Available (parágrafo do texto Este projeto toma como preocupação básica as tarefas de preservação e valorização do patrimônio cultural do país: a "memória nacional", isto é, o conhecimento de nossa identidade, de nossa vida social. E isto diz respeito diretamente, portanto, ao homem brasi-leiro na sua integralidade.

  19. Conditional use of social and private information guides house-hunting ants.

    Science.gov (United States)

    Cronin, Adam L

    2013-01-01

    Social animals can use both social and private information to guide decision making. While social information can be relatively economical to acquire, it can lead to maladaptive information cascades if attention to environmental cues is supplanted by unconditional copying. Ants frequently employ pheromone trails, a form of social information, to guide collective processes, and this can include consensus decisions made when choosing a place to live. In this study, I examine how house-hunting ants balance social and private information when these information sources conflict to different degrees. Social information, in the form of pre-established pheromone trails, strongly influenced the decision process in choices between equivalent nests, and lead to a reduced relocation time. When trails lead to non-preferred types of nest, however, social information had less influence when this preference was weak and no influence when the preference was strong. These results suggest that social information is vetted against private information during the house-hunting process in this species. Private information is favoured in cases of conflict and this may help insure colonies against costly wrong decisions.

  20. Conditional use of social and private information guides house-hunting ants.

    Directory of Open Access Journals (Sweden)

    Adam L Cronin

    Full Text Available Social animals can use both social and private information to guide decision making. While social information can be relatively economical to acquire, it can lead to maladaptive information cascades if attention to environmental cues is supplanted by unconditional copying. Ants frequently employ pheromone trails, a form of social information, to guide collective processes, and this can include consensus decisions made when choosing a place to live. In this study, I examine how house-hunting ants balance social and private information when these information sources conflict to different degrees. Social information, in the form of pre-established pheromone trails, strongly influenced the decision process in choices between equivalent nests, and lead to a reduced relocation time. When trails lead to non-preferred types of nest, however, social information had less influence when this preference was weak and no influence when the preference was strong. These results suggest that social information is vetted against private information during the house-hunting process in this species. Private information is favoured in cases of conflict and this may help insure colonies against costly wrong decisions.

  1. El dilema del arte popular en Bolivia

    Directory of Open Access Journals (Sweden)

    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

  2. Plant defences against ants provide a pathway to social parasitism in butterflies

    Science.gov (United States)

    Patricelli, Dario; Barbero, Francesca; Occhipinti, Andrea; Bertea, Cinzia M.; Bonelli, Simona; Casacci, Luca P.; Zebelo, Simon A.; Crocoll, Christoph; Gershenzon, Jonathan; Maffei, Massimo E.; Thomas, Jeremy A.; Balletto, Emilio

    2015-01-01

    Understanding the chemical cues and gene expressions that mediate herbivore–host-plant and parasite–host interactions can elucidate the ecological costs and benefits accruing to different partners in tight-knit community modules, and may reveal unexpected complexities. We investigated the exploitation of sequential hosts by the phytophagous–predaceous butterfly Maculinea arion, whose larvae initially feed on Origanum vulgare flowerheads before switching to parasitize Myrmica ant colonies for their main period of growth. Gravid female butterflies were attracted to Origanum plants that emitted high levels of the monoterpenoid volatile carvacrol, a condition that occurred when ants disturbed their roots: we also found that Origanum expressed four genes involved in monoterpene formation when ants were present, accompanied by a significant induction of jasmonates. When exposed to carvacrol, Myrmica workers upregulated five genes whose products bind and detoxify this biocide, and their colonies were more tolerant of it than other common ant genera, consistent with an observed ability to occupy the competitor-free spaces surrounding Origanum. A cost is potential colony destruction by Ma. arion, which in turn may benefit infested Origanum plants by relieving their roots of further damage. Our results suggest a new pathway, whereby social parasites can detect successive resources by employing plant volatiles to simultaneously select their initial plant food and a suitable sequential host. PMID:26156773

  3. Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size.

    Science.gov (United States)

    Keiser, Carl N; Wright, Colin M; Pruitt, Jonathan N

    2015-10-01

    Sociality provides individuals with benefits via collective foraging and anti-predator defense. One of the costs of living in large groups, however, is increased apparency to natural enemies. Here, we test how the individual-level and collective traits of spider societies can increase the risk of discovery and death by predatory ants. We transplanted colonies of the social spider Stegodyphus dumicola into a habitat dense with one of their top predators, the pugnacious ant Anoplolepis custodiens. With three different experiments, we test how colony-wide survivorship in a predator-dense habitat can be altered by colony apparency (i.e., the presence of a capture web), group size, and group composition (i.e., the proportion of bold and shy personality types present). We also test how spiders' social context (i.e., living solitarily vs. among conspecifics) modifies their behaviour toward ants in their capture web. Colonies with capture webs intact were discovered by predatory ants on average 25% faster than colonies with the capture web removed, and all discovered colonies eventually collapsed and succumbed to predation. However, the lag time from discovery by ants to colony collapse was greater for colonies containing more individuals. The composition of individual personality types in the group had no influence on survivorship. Spiders in a social group were more likely to approach ants caught in their web than were isolated spiders. Isolated spiders were more likely to attack a safe prey item (a moth) than they were to attack ants and were more likely to retreat from ants after contact than they were after contact with moths. Together, our data suggest that the physical structures produced by large animal societies can increase their apparency to natural enemies, though larger groups can facilitate a longer lag time between discovery and demise. Lastly, the interaction between spiders and predatory ants seems to depend on the social context in which spiders reside

  4. Genetic regulation of colony social organization in fire ants: an integrative overview.

    Science.gov (United States)

    Gotzek, Dietrich; Ross, Kenneth G

    2007-09-01

    Expression of colony social organization in fire ants appears to be under the control of a single Mendelian factor of large effect. Variation in colony queen number in Solenopsis invicta and its relatives is associated with allelic variation at the gene Gp-9, but not with variation at other unlinked genes; workers regulate queen identity and number on the basis of Gp-9 genotypic compatibility. Nongenetic factors, such as prior social experience, queen reproductive status, and local environment, have negligible effects on queen numbers which illustrates the nearly complete penetrance of Gp-9. As predicted, queen number can be manipulated experimentally by altering worker Gp-9 genotype frequencies. The Gp-9 allele lineage associated with polygyny in South American fire ants has been retained across multiple speciation events, which may signal the action of balancing selection to maintain social polymorphism in these species. Moreover, positive selection is implicated in driving the molecular evolution of Gp-9 in association with the origin of polygyny. The identity of the product of Gp-9 as an odorant-binding protein suggests plausible scenarios for its direct involvement in the regulation of queen number via a role in chemical communication. While these and other lines of evidence show that Gp-9 represents a legitimate candidate gene of major effect, studies aimed at determining (i) the biochemical pathways in which GP-9 functions; (ii) the phenotypic effects of molecular variation at Gp-9 and other pathway genes; and (iii) the potential involvement of genes in linkage disequilibrium with Gp-9 are needed to elucidate the genetic architecture underlying social organization in fire ants. Information that reveals the links between molecular variation, individual phenotype, and colony-level behaviors, combined with behavioral models that incorporate details of the chemical communication involved in regulating queen number, will yield a novel integrated view of the

  5. Social transfer of pathogenic fungus promotes active immunisation in ant colonies.

    Directory of Open Access Journals (Sweden)

    Matthias Konrad

    Full Text Available Due to the omnipresent risk of epidemics, insect societies have evolved sophisticated disease defences at the individual and colony level. An intriguing yet little understood phenomenon is that social contact to pathogen-exposed individuals reduces susceptibility of previously naive nestmates to this pathogen. We tested whether such social immunisation in Lasius ants against the entomopathogenic fungus Metarhizium anisopliae is based on active upregulation of the immune system of nestmates following contact to an infectious individual or passive protection via transfer of immune effectors among group members--that is, active versus passive immunisation. We found no evidence for involvement of passive immunisation via transfer of antimicrobials among colony members. Instead, intensive allogrooming behaviour between naive and pathogen-exposed ants before fungal conidia firmly attached to their cuticle suggested passage of the pathogen from the exposed individuals to their nestmates. By tracing fluorescence-labelled conidia we indeed detected frequent pathogen transfer to the nestmates, where they caused low-level infections as revealed by growth of small numbers of fungal colony forming units from their dissected body content. These infections rarely led to death, but instead promoted an enhanced ability to inhibit fungal growth and an active upregulation of immune genes involved in antifungal defences (defensin and prophenoloxidase, PPO. Contrarily, there was no upregulation of the gene cathepsin L, which is associated with antibacterial and antiviral defences, and we found no increased antibacterial activity of nestmates of fungus-exposed ants. This indicates that social immunisation after fungal exposure is specific, similar to recent findings for individual-level immune priming in invertebrates. Epidemiological modeling further suggests that active social immunisation is adaptive, as it leads to faster elimination of the disease and lower

  6. Social influences on ant-dipping acquisition in the wild chimpanzees (Pan troglodytes verus) of Bossou, Guinea, West Africa.

    Science.gov (United States)

    Humle, Tatyana; Snowdon, Charles T; Matsuzawa, Tetsuro

    2009-10-01

    We currently have little understanding of the influence of learning opportunity, whether social or environmental, and maternal role on tool-use acquisition in young wild chimpanzees. This study aims to fill this gap by focusing on the acquisition of ant-dipping among chimpanzees of Bossou, Guinea. Ant-dipping is a hazardous tool-use behaviour aimed at army ants (Dorylus spp.). Bossou chimpanzees target these ants both at nests (high risk) and trails (low risk) and employ two techniques to consume them: direct mouthing and pull-through. We present data for 13 mother-offspring pairs (1-10 years old). Mothers with young chimpanzee material culture is a product of a complex interaction between social processes and ecological factors.

  7. Plant defences against ants provide a pathway to social parasitism in butterflies

    DEFF Research Database (Denmark)

    Patricelli, Dario; Barbero, Francesca; Occhipinti, Andrea

    2015-01-01

    , which in turn may benefit infested Origanum plants by relieving their roots of further damage. Our results suggest a new pathway, whereby social parasites can detect successive resources by employing plant volatiles to simultaneously select their initial plant food and a suitable sequential host....... the exploitation of sequential hosts by the phytophagous-predaceous butterfly Maculinea arion, whose larvae initially feed on Origanum vulgare flowerheads before switching to parasitize Myrmica ant colonies for their main period of growth. Gravid female butterflies were attracted to Origanum plants that emitted...

  8. La evaluación de la política social en México: avances recientes, tareas pendientes y dilemas persistentes

    OpenAIRE

    Acosta, Félix

    2010-01-01

    El propósito general de este trabajo consiste en hacer un análisis de los avances en el proceso de institucionalización de la evaluación de la política social en México a partir de 2006 y señalar algunas ideas para lograr que la evaluación de la política social contribuya a mejorar la rendición de cuentas, la transparencia, la participación social, la eficiencia y la eficacia social de las acciones del gobierno orientadas a mejorar el bienestar de la población y a combatir la desigualdad soci...

  9. Collective defence portfolios of ant hosts shift with social parasite pressure.

    Science.gov (United States)

    Jongepier, Evelien; Kleeberg, Isabelle; Job, Sylwester; Foitzik, Susanne

    2014-09-22

    Host defences become increasingly costly as parasites breach successive lines of defence. Because selection favours hosts that successfully resist parasitism at the lowest possible cost, escalating coevolutionary arms races are likely to drive host defence portfolios towards ever more expensive strategies. We investigated the interplay between host defence portfolios and social parasite pressure by comparing 17 populations of two Temnothorax ant species. When successful, collective aggression not only prevents parasitation but also spares host colonies the cost of searching for and moving to a new nest site. However, once parasites breach the host's nest defence, host colonies should resort to flight as the more beneficial resistance strategy. We show that under low parasite pressure, host colonies more likely responded to an intruding Protomognathus americanus slavemaker with collective aggression, which prevented the slavemaker from escaping and potentially recruiting nest-mates. However, as parasite pressure increased, ant colonies of both host species became more likely to flee rather than to fight. We conclude that host defence portfolios shift consistently with social parasite pressure, which is in accordance with the degeneration of frontline defences and the evolution of subsequent anti-parasite strategies often invoked in hosts of brood parasites. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  10. Multiple Convergent Origins of Workerlessness and Inbreeding in the Socially Parasitic Ant Genus Myrmoxenus.

    Science.gov (United States)

    Heinze, Jürgen; Buschinger, Alfred; Poettinger, Theo; Suefuji, Masaki

    2015-01-01

    The socially parasitic ant genus Myrmoxenus varies strongly in fundamental life history traits, such as queen-worker ratio, the timing of sexual production, and mating behavior. Myrmoxenus queens generally take over nests of Temnothorax ants, kill the resident queen by throttling, and force the workers to take care of the social parasite's brood. Young queens of M. ravouxi and other species produce large numbers of workers, which during "slave-raids" pillage host pupae from neighboring Temnothorax colonies to increase the workforce in their own nests. Other species, such as M. corsicus, have lost caste polyphenism and rear only male and female sexual offspring. Using sequences of the genes CO I/CO II and wingless we reconstruct the phylogeny of Myrmoxenus and document that the worker caste was lost convergently at least three times. Furthermore, mating in the nest and inbreeding obviously also evolved in parallel from ancestors whose sexuals presumably mated during nuptial flights. Myrmoxenus might thus provide a suitable model to investigate caste differentiation and the plasticity of mating behavior in Hymenoptera.

  11. Multiple Convergent Origins of Workerlessness and Inbreeding in the Socially Parasitic Ant Genus Myrmoxenus.

    Directory of Open Access Journals (Sweden)

    Jürgen Heinze

    Full Text Available The socially parasitic ant genus Myrmoxenus varies strongly in fundamental life history traits, such as queen-worker ratio, the timing of sexual production, and mating behavior. Myrmoxenus queens generally take over nests of Temnothorax ants, kill the resident queen by throttling, and force the workers to take care of the social parasite's brood. Young queens of M. ravouxi and other species produce large numbers of workers, which during "slave-raids" pillage host pupae from neighboring Temnothorax colonies to increase the workforce in their own nests. Other species, such as M. corsicus, have lost caste polyphenism and rear only male and female sexual offspring. Using sequences of the genes CO I/CO II and wingless we reconstruct the phylogeny of Myrmoxenus and document that the worker caste was lost convergently at least three times. Furthermore, mating in the nest and inbreeding obviously also evolved in parallel from ancestors whose sexuals presumably mated during nuptial flights. Myrmoxenus might thus provide a suitable model to investigate caste differentiation and the plasticity of mating behavior in Hymenoptera.

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

    OpenAIRE

    Uva Falla Ramírez

    2012-01-01

    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 qu...

  13. 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....

  14. Molecular variation at a candidate gene implicated in the regulation of fire ant social behavior.

    Directory of Open Access Journals (Sweden)

    Dietrich Gotzek

    2007-11-01

    Full Text Available The fire ant Solenopsis invicta and its close relatives display an important social polymorphism involving differences in colony queen number. Colonies are headed by either a single reproductive queen (monogyne form or multiple queens (polygyne form. This variation in social organization is associated with variation at the gene Gp-9, with monogyne colonies harboring only B-like allelic variants and polygyne colonies always containing b-like variants as well. We describe naturally occurring variation at Gp-9 in fire ants based on 185 full-length sequences, 136 of which were obtained from S. invicta collected over much of its native range. While there is little overall differentiation between most of the numerous alleles observed, a surprising amount is found in the coding regions of the gene, with such substitutions usually causing amino acid replacements. This elevated coding-region variation may result from a lack of negative selection acting to constrain amino acid replacements over much of the protein, different mutation rates or biases in coding and non-coding sequences, negative selection acting with greater strength on non-coding than coding regions, and/or positive selection acting on the protein. Formal selection analyses provide evidence that the latter force played an important role in the basal b-like lineages coincident with the emergence of polygyny. While our data set reveals considerable paraphyly and polyphyly of S. invicta sequences with respect to those of other fire ant species, the b-like alleles of the socially polymorphic species are monophyletic. An expanded analysis of colonies containing alleles of this clade confirmed the invariant link between their presence and expression of polygyny. Finally, our discovery of several unique alleles bearing various combinations of b-like and B-like codons allows us to conclude that no single b-like residue is completely predictive of polygyne behavior and, thus, potentially causally

  15. 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...

  16. Competitividade empresarial, gestão de pessoas e controle social: para pensar os dilemas da Qualidade de Vida no Trabalho (QVT

    Directory of Open Access Journals (Sweden)

    Erika Barboza de Souza

    2015-07-01

    Full Text Available Atualmente, discutir temas como Qualidade de Vida no Trabalho (QVT no âmbito das organizações tem sido fundamental para enfrentar a concorrência acirrada no mundo dos negócios, com o intuito de tornar a vida dos trabalhadores menos fatigante e, consequentemente, alavancar a produtividade e a qualidade dos produtos e serviços da empresa. Por outro lado, alguns autores têm criticado fortemente esses programas, uma vez que acreditam tratar-se de uma “maquiagem” de controle dos indivíduos pelas empresas. Para eles, existe um conflito essencial entre o capital e os interesses dos indivíduos. Essa ideia remete a instrumentalização do indivíduo através do controle social sem a devida tomada de consciência. Nesse sentido, este artigo surge com o intuito de compreender as discussões existentes sobre QVT, relacionando a égide da valorização dos recursos humanos no atual contexto do mundo capitalista com os processos objetivos e subjetivos de precarização do trabalho. Essa reflexão se justifica na tentativa de despertar uma análise crítica sobre os programas de QVT, aspirando novas ponderações sobre planejamento, gestão e bem-estar do trabalhador. Dessa forma, é possível concluir que a ação de acabar com as práticas assistencialistas e implantar uma abordagem alternativa em QVT, de caráter sustentável, seria o caminho mais adequado para o equilíbrio das satisfações nas relações trabalhistas. Uma estratégia estrutural seria a criação de formas estáveis e padronizadas de relações de trabalho e de segurança no emprego, reduzindo, por mérito, o temor da instabilidade contratual e de renda, das responsabilidades laborais e da própria saúde ocupacional dos trabalhadores.

  17. Percepción del clima social familiar y actitudes ante el acoso escolar en adolescentes

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    María de la Villa Moral Jiménez

    2013-08-01

    Full Text Available La implicación de los factores familiares en la problemática del acoso escolar entre iguales está suficientemente documentada, no solo en lo relativo a los distintos perfiles diferenciales que presentan los bullies y sus víctimas en lo referente a los estilos socializadores paternos, sino por las implicaciones que se derivan de la percepción del clima familiar. En concreto, en este estudio se ofrece un análisis psicosocial de la vinculación entre la percepción del clima social familiar por parte de un colectivo de 550 adolescentes del Principado de Asturias (278 chicas, 50.5% y 272 chicos, 49.5% y sus actitudes ante el acoso escolar de acuerdo con un modelo de evaluación tridimensional (planos cognitivo, afectivo y disposicional medidas a través de la Escala de actitudes ante la agresión social construida ad hoc por los autores (Moral, 2005. Se ha confirmado que los adolescentes que presentan actitudes más favorables a la violencia entre iguales perciben un clima familiar más conflictivo, sienten menor afecto en las relaciones familiares, manifiestan una mayor dificultad para comunicarse con ellos, así como un menor respeto hacia sus opiniones y un mayor nivel de exigencia paterna y declaran ser objeto de castigo físico y psicológico por parte de sus padres en comparación con aquellos adolescentes que presentan unas actitudes más negativas hacia la violencia bullying.

  18. 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

  19. Host recognition by the specialist hoverfly Microdon mutabilis, a social parasite of the ant Formica lemani.

    Science.gov (United States)

    Schönrogge, Karsten; Napper, Emma K V; Birkett, Michael A; Woodcock, Christine M; Pickett, John A; Wadhams, Lester J; Thomas, Jeremy A

    2008-02-01

    The larva of the hoverfly Microdon mutabilis is a specialist social parasite of the ant Formica lemani that is adapted to local groups of F. lemani colonies but mal-adapted to colonies of the same species situated only a few hundred meters away. At a study site in Ireland, F. lemani shares its habitat with four other ant species. All nest under stones, making the oviposition choice by M. mutabilis females crucial to offspring survival. In this study, we tested the hypothesis that, as an extreme specialist, M. mutabilis should respond to cues derived from its host rather than from its microenvironment, a phenomenon that has hitherto only been addressed in the context of herbivorous insects and their parasitoids. In behavioral assays, M. mutabilis females reacted to volatiles from F. lemani colonies by extending their ovipositors, presumably probing for an oviposition substrate. This behavior was not observed toward negative controls or volatiles from colonies of Myrmica scabrinodis, the host ant of the closely related Microdon myrmicae. Coupled gas chromatography-electroantennography (GC-EAG) that used antennal preparations of M. mutabilis located a single physiologically active compound within an extract of heads of F. lemani workers. Coupled GC-mass spectrometry (GC-MS) tentatively identified the compound as a methylated methylsalicylate. GC co-injection of the extract with authentic samples showed that of the four possible isomers (methyl 3-, 4-, 5-, and 6-methylsalicylate), only methyl 6-methylsalicylate co-eluted with the EAG-active peak. Furthermore, the response to methyl 6-methylsalicylate was four times higher than to those of the other isomers. Coupled GC-EAG and GC-MS also revealed physiological responses to two constituents, 3-octanone and 3-octanol, of the M. scabrinodis alarm pheromone. However, the behavioral trials did not reveal any behavior that could be attributed to these compounds. Results are discussed in the context of four phases of host

  20. Strict monandry in the ponerine army ant genus Simopelta suggests that colony size and complexity drive mating system evolution in social insects

    DEFF Research Database (Denmark)

    Kronauer, Daniel J C; O'Donnell, Sean; Boomsma, Jacobus J

    2011-01-01

    -ratios have convergently shaped these mating systems. Here we show that ponerine army ants of the genus Simopelta, which are distantly related but similar in general biology to other army ants, have strictly monandrous queens. Preliminary data suggest that workers reproduce in queenright colonies, which...... is in sharp contrast to other army ants. We hypothesize that differences in mature colony size and social complexity may explain these striking discrepancies....

  1. The Antsy Social Network: Determinants of Nest Structure and Arrangement in Asian Weaver Ants

    OpenAIRE

    Devarajan, Kadambari

    2016-01-01

    Asian weaver ants (Oecophylla smaragdina) are arboreal ants that are known to form mutualistic complexes with their host trees. They are eusocial ants that build elaborate nests in the canopy in tropical areas. A colony comprises of multiple nests, usually on multiple trees, and the boundaries of the colony may be difficult to identify. However, they provide the ideal model for studying group living in invertebrates since there are a definite number of nests for a given substrate, the tree. H...

  2. Optimising social information by game theory and ant colony method to enhance routing protocol in opportunistic networks

    Directory of Open Access Journals (Sweden)

    Chander Prabha

    2016-09-01

    Full Text Available The data loss and disconnection of nodes are frequent in the opportunistic networks. The social information plays an important role in reducing the data loss because it depends on the connectivity of nodes. The appropriate selection of next hop based on social information is critical for improving the performance of routing in opportunistic networks. The frequent disconnection problem is overcome by optimising the social information with Ant Colony Optimization method which depends on the topology of opportunistic network. The proposed protocol is examined thoroughly via analysis and simulation in order to assess their performance in comparison with other social based routing protocols in opportunistic network under various parameters settings.

  3. Persistence of the single lineage of transmissible 'social cancer' in an asexual ant.

    Science.gov (United States)

    Dobata, S; Sasaki, T; Mori, H; Hasegawa, E; Shimada, M; Tsuji, K

    2011-02-01

    How cooperation can arise and persist, given the threat of cheating phenotypes, is a central problem in evolutionary biology, but the actual significance of cheating in natural populations is still poorly understood. Theories of social evolution predict that cheater lineages are evolutionarily short-lived. However, an exception comes from obligate socially parasitic species, some of which thought to have arisen as cheaters within cooperator colonies and then diverged through sympatric speciation. This process requires the cheater lineage to persist by avoiding rapid extinction that would result from the fact that the cheaters inflict fitness cost on their host. We examined whether this prerequisite is fulfilled, by estimating the persistence time of cheaters in a field population of the parthenogenetic ant Pristomyrmex punctatus. Population genetic analysis found that the cheaters belong to one monophyletic lineage which we infer has persisted for 200-9200 generations. We show that the cheaters migrate and are thus horizontally transmitted between colonies, a trait allowing the lineage to avoid rapid extinction with its host colony. Although horizontal transmission of disruptive cheaters has the potential to induce extinction of the entire population, such collapse is likely averted when there is spatially restricted migration in a structured population, a scenario that matches the observed isolation by distance pattern that we found. We compare our result with other examples of disruptive and horizontally transmissible cheater lineages in nature. © 2010 Blackwell Publishing Ltd.

  4. First evidence for slave rebellion: enslaved ant workers systematically kill the brood of their social parasite protomognathus americanus.

    Science.gov (United States)

    Achenbach, Alexandra; Foitzik, Susanne

    2009-04-01

    During the process of coevolution, social parasites have evolved sophisticated strategies to exploit the brood care behavior of their social hosts. Slave-making ant queens invade host colonies and kill or eject all adult host ants. Host workers, which eclose from the remaining brood, are tricked into caring for the parasite brood. Due to their high prevalence and frequent raids, following which stolen host broods are similarly enslaved, slave-making ants exert substantial selection upon their hosts, leading to the evolution of antiparasite adaptations. However, all host defenses shown to date are active before host workers are parasitized, whereas selection was thought to be unable to act on traits of already enslaved hosts. Yet, here we demonstrate the rebellion of enslaved Temnothorax workers, which kill two-thirds of the female pupae of the slave-making ant Protomognathus americanus. Thereby, slaves decrease the long-term parasite impact on surrounding related host colonies. This novel antiparasite strategy of enslaved workers constitutes a new level in the coevolutionary battle after host colony defense has failed. Our discovery is analogous to recent findings in hosts of avian brood parasites where perfect mimicry of parasite eggs leads to the evolution of chick recognition as a second line of defense.

  5. Transcriptome characterisation of the ant Formica exsecta with new insights into the evolution of desaturase genes in social hymenoptera.

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    Hélène Badouin

    Full Text Available BACKGROUND: Despite the recent sequencing of seven ant genomes, no genomic data are available for the genus Formica, an important group for the study of eusocial traits. We sequenced the transcriptome of the ant Formica exsecta with the 454 FLX Titanium technology from a pooled sample of workers from 70 Finnish colonies. RESULTS: About 1,000,000 reads were obtained from a normalised cDNA library. We compared the assemblers MIRA3.0 and Newbler2.6 and showed that the latter performed better on this dataset due to a new option which is dedicated to improve contig formation in low depth portions of the assemblies. The 29,579 contigs represent 27 Mb. 50% showed similarity with known proteins and 25% could be assigned a category of gene ontology. We found more than 13,000 high-quality single nucleotide polymorphisms. The Δ9 desaturase gene family is an important multigene family involved in chemical communication in insects. We found six Δ9 desaturases in this Formica exsecta transcriptome dataset that were used to reconstruct a maximum-likelihood phylogeny of insect desaturases and to test for signatures of positive selection in this multigene family in ant lineages. We found differences with previous phylogenies of this gene family in ants, and found two clades potentially under positive selection. CONCLUSION: This first transcriptome reference sequence of Formica exsecta provided sequence and polymorphism data that will allow researchers working on Formica ants to develop studies to tackle the genetic basis of eusocial phenotypes. In addition, this study provided some general guidelines for de novo transcriptome assembly that should be useful for future transcriptome sequencing projects. Finally, we found potential signatures of positive selection in some clades of the Δ9 desaturase gene family in ants, which suggest the potential role of sequence divergence and adaptive evolution in shaping the large diversity of chemical cues in social insects.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Carbon dioxide sensing in the social context: Leaf-cutting ants prefer elevated CO2 levels to tend their brood.

    Science.gov (United States)

    Römer, Daniela; Bollazzi, Martin; Roces, Flavio

    2018-05-18

    Social insects show temperature and humidity preferences inside their nests to successfully rear brood. In underground nests, ants also encounter rising CO 2 concentrations with increasing depth. It is an open question whether they use CO 2 as a cue to decide where to place and tend the brood. Leaf-cutting ants do show CO 2 preferences for the culturing of their symbiotic fungus. We evaluated their CO 2 choices for brood placement in laboratory experiments. Workers of Acromyrmex lundii in the process of relocating brood were offered a binary choice consisting of two interconnected chambers with different CO 2 concentrations. Values ranged from atmospheric to high concentrations of 4% CO 2 . The CO 2 preferences shown by workers for themselves and for brood placement were assessed by quantifying the number of workers and relocated brood in each chamber. Ants showed clear CO 2 preferences for brood placement. They avoided atmospheric levels, 1% and 4% CO 2 , and showed a preference for levels of 3%. This is the first report of CO 2 preferences for the maintenance of brood in social insects. The observed preferences for brood location were independent of the workers' own CO 2 preferences, since they showed no clear-cut pattern. Workers' CO 2 preferences for brood maintenance were slightly higher than those reported for fungus culturing, although brood is reared in the same chambers as the fungus in leaf-cutting ant nests. Workers' choices for brood placement in natural nests are likely the result of competing preferences for other environmental factors more crucial for brood survival, aside from those for CO 2 . Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Changes in mating system and social structure of the ant Petalomyrmex phylax are associated with range expansion in Cameroon.

    Science.gov (United States)

    Dalecky, Ambroise; Debout, Gabriel; Estoup, Arnaud; McKey, Doyle B; Kjellberg, Finn

    2007-03-01

    Past climate shifts have led to major oscillations in species distributions. Hence historical contingencies and selective processes occurring during such phases may be determinants for understanding the forces that have shaped extant phenotypes. In the plant-ant Petalomyrmex phylax (Formicinae), we observed spatial variation in number of queens in mature colonies, from several queens (high polygyny) in the median part of its distribution to a moderate number of queens (weak polygyny) or even only a single queen (monogyny) in the southwesternmost populations. This variation did not correlate with indicators of variation in current nest site availability and colony turnover, the supposedly determinant selective forces acting on gyny in ants. We show here that the variation in social structure correlates with a historical process corresponding to a progressive colonization of coastal southern Cameroon by the ant. Using microsatellite markers, we observed a clear pattern of isolation by distance except for the southernmost populations. Measures of genetic variability that do not take into account allele size were at equilibrium in all except the southernmost populations, suggesting recent foundation of the latter. Measures of genetic diversity taking into account allele size showed a clinal north-south decrease in variance of allele size. We propose that southern populations have yet to regain allele size variance after bottlenecks associated with the foundation of new populations, and that this variance is regained over time. Hence variation in social structure mirrors an old but still active southward colonization process or metapopulation dynamics, possibly in association with an expansion of the rain forest habitat during the late Holocene. A low number of queens in ant colonies is typically associated with strong dispersal capacity. We therefore suggest that the initial founders of new populations belong to the monogynous to weakly polygynous phenotype, and that

  9. Cuticular Hydrocarbon Pheromones for Social Behavior and Their Coding in the Ant Antenna

    Directory of Open Access Journals (Sweden)

    Kavita R. Sharma

    2015-08-01

    Full Text Available The sophisticated organization of eusocial insect societies is largely based on the regulation of complex behaviors by hydrocarbon pheromones present on the cuticle. We used electrophysiology to investigate the detection of cuticular hydrocarbons (CHCs by female-specific olfactory sensilla basiconica on the antenna of Camponotus floridanus ants through the utilization of one of the largest family of odorant receptors characterized so far in insects. These sensilla, each of which contains multiple olfactory receptor neurons, are differentially sensitive to CHCs and allow them to be classified into three broad groups that collectively detect every hydrocarbon tested, including queen and worker-enriched CHCs. This broad-spectrum sensitivity is conserved in a related species, Camponotus laevigatus, allowing these ants to detect CHCs from both nestmates and non-nestmates. Behavioral assays demonstrate that these ants are excellent at discriminating CHCs detected by the antenna, including enantiomers of a candidate queen pheromone that regulates the reproductive division of labor.

  10. First record of the vulnerable social parasite ant Plagiolepis grassei in Italy (Hymenoptera: Formicidae

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    Enrico Schifani

    2017-06-01

    Full Text Available The first Italian records of the rare parasitic ant species Plagiolepis grassei Le Masne, 1956 are here reported. This species is considered as “Vulnerable” by the IUCN’s Red List, and was previously recorded from France and Spain only.

  11. Reproductive conflict in social insects: Male production by workers in a slave-making ant

    DEFF Research Database (Denmark)

    Brunner, Elizabeth; Trindl, Andreas; Falk, Karl H.

    2005-01-01

    by producing their own sons than workers in nonparasitic species. In this study we investigated worker reproduction in four natural colonies of the slave-making ant Polyergus rufescens, using highly variable microsatellite markers. Our results show that workers produce up to 100% of the males. This study thus...

  12. 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

  13. Friends and foes from an ant brain's point of view--neuronal correlates of colony odors in a social insect.

    Science.gov (United States)

    Brandstaetter, Andreas Simon; Rössler, Wolfgang; Kleineidam, Christoph Johannes

    2011-01-01

    Successful cooperation depends on reliable identification of friends and foes. Social insects discriminate colony members (nestmates/friends) from foreign workers (non-nestmates/foes) by colony-specific, multi-component colony odors. Traditionally, complex processing in the brain has been regarded as crucial for colony recognition. Odor information is represented as spatial patterns of activity and processed in the primary olfactory neuropile, the antennal lobe (AL) of insects, which is analogous to the vertebrate olfactory bulb. Correlative evidence indicates that the spatial activity patterns reflect odor-quality, i.e., how an odor is perceived. For colony odors, alternatively, a sensory filter in the peripheral nervous system was suggested, causing specific anosmia to nestmate colony odors. Here, we investigate neuronal correlates of colony odors in the brain of a social insect to directly test whether they are anosmic to nestmate colony odors and whether spatial activity patterns in the AL can predict how odor qualities like "friend" and "foe" are attributed to colony odors. Using ant dummies that mimic natural conditions, we presented colony odors and investigated their neuronal representation in the ant Camponotus floridanus. Nestmate and non-nestmate colony odors elicited neuronal activity: In the periphery, we recorded sensory responses of olfactory receptor neurons (electroantennography), and in the brain, we measured colony odor specific spatial activity patterns in the AL (calcium imaging). Surprisingly, upon repeated stimulation with the same colony odor, spatial activity patterns were variable, and as variable as activity patterns elicited by different colony odors. Ants are not anosmic to nestmate colony odors. However, spatial activity patterns in the AL alone do not provide sufficient information for colony odor discrimination and this finding challenges the current notion of how odor quality is coded. Our result illustrates the enormous challenge

  14. Social chromosome variants differentially affect queen determination and the survival of workers in the fire ant Solenopsis invicta.

    Science.gov (United States)

    Buechel, Séverine D; Wurm, Yanick; Keller, Laurent

    2014-10-01

    Intraspecific variation in social organization is common, yet the underlying causes are rarely known. An exception is the fire ant Solenopsis invicta in which the existence of two distinct forms of social colony organization is under the control of the two variants of a pair of social chromosomes, SB and Sb. Colonies containing exclusively SB/SB workers accept only one single queen and she must be SB/SB. By contrast, when colonies contain more than 10% of SB/Sb workers, they accept several queens but only SB/Sb queens. The variants of the social chromosome are associated with several additional important phenotypic differences, including the size, fecundity and dispersal strategies of queens, aggressiveness of workers, and sperm count in males. However, little is known about whether social chromosome variants affect fitness in other life stages. Here, we perform experiments to determine whether differential selection occurs during development and in adult workers. We find evidence that the Sb variant of the social chromosome increases the likelihood of female brood to develop into queens and that adult SB/Sb workers, the workers that cull SB/SB queens, are overrepresented in comparison to SB/SB workers. This demonstrates that supergenes such as the social chromosome can have complex effects on phenotypes at various stages of development. © 2014 John Wiley & Sons Ltd.

  15. Social life and sanitary risks: evolutionary and current ecological conditions determine waste management in leaf-cutting ants.

    Science.gov (United States)

    Farji-Brener, Alejandro G; Elizalde, Luciana; Fernández-Marín, Hermógenes; Amador-Vargas, Sabrina

    2016-05-25

    Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. © 2016 The Author(s).

  16. La mujer como sujeto social ante el problema ambiental desde la realidad cubana./The woman as a social subject to the environmental problem from the Cuban reality.

    Directory of Open Access Journals (Sweden)

    Luisa Carrión Cabrera

    2015-09-01

    Full Text Available RESUMEN El análisis de la mujer como sujeto social ante el problema ambiental en el contexto cubano, se convierte en una necesidad para alcanzar el desarrollo sostenible, para dicho análisis se discuten acerca de los cuatro ejes que facilitan la valoración de los procesos sociales en su vínculo con el medio ambiente (lo ambiental como problemática en la producción filosófica en el contexto cubano y su relación con la mujer como sujeto social; el desequilibrio en las condiciones de existencia en los espacios privados (familiar; los problemas ambientales y su impacto en la mujer y el papel creciente de la actividad social del sujeto, a partir de sus tipos y proyecciones sociales para el logro del desarrollo sostenible. ABSTRACT The analysis of women as social subject to the environmental problem in the Cuban context, it becomes a necessity for sustainable development, for this analysis are discussed on the four axes that facilitate the assessment of social processes in its link with the environment (environmental and philosophical problems in production in the Cuban context and its relationship with the woman as a social subject, the imbalance in living conditions in the private sphere (family environmental problems and their impact on women and the increasing role of the social activity of the subject, based on their types and social implications for the achievement of sustainable development.

  17. Intraspecific Variation among Social Insect Colonies: Persistent Regional and Colony-Level Differences in Fire Ant Foraging Behavior.

    Directory of Open Access Journals (Sweden)

    Alison A Bockoven

    Full Text Available Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior.

  18. 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...

  19. Friends and Foes from an Ant Brain's Point of View – Neuronal Correlates of Colony Odors in a Social Insect

    Science.gov (United States)

    Brandstaetter, Andreas Simon; Rössler, Wolfgang; Kleineidam, Christoph Johannes

    2011-01-01

    Background Successful cooperation depends on reliable identification of friends and foes. Social insects discriminate colony members (nestmates/friends) from foreign workers (non-nestmates/foes) by colony-specific, multi-component colony odors. Traditionally, complex processing in the brain has been regarded as crucial for colony recognition. Odor information is represented as spatial patterns of activity and processed in the primary olfactory neuropile, the antennal lobe (AL) of insects, which is analogous to the vertebrate olfactory bulb. Correlative evidence indicates that the spatial activity patterns reflect odor-quality, i.e., how an odor is perceived. For colony odors, alternatively, a sensory filter in the peripheral nervous system was suggested, causing specific anosmia to nestmate colony odors. Here, we investigate neuronal correlates of colony odors in the brain of a social insect to directly test whether they are anosmic to nestmate colony odors and whether spatial activity patterns in the AL can predict how odor qualities like “friend” and “foe” are attributed to colony odors. Methodology/Principal Findings Using ant dummies that mimic natural conditions, we presented colony odors and investigated their neuronal representation in the ant Camponotus floridanus. Nestmate and non-nestmate colony odors elicited neuronal activity: In the periphery, we recorded sensory responses of olfactory receptor neurons (electroantennography), and in the brain, we measured colony odor specific spatial activity patterns in the AL (calcium imaging). Surprisingly, upon repeated stimulation with the same colony odor, spatial activity patterns were variable, and as variable as activity patterns elicited by different colony odors. Conclusions Ants are not anosmic to nestmate colony odors. However, spatial activity patterns in the AL alone do not provide sufficient information for colony odor discrimination and this finding challenges the current notion of how odor

  20. El estado del bienestar social y el neoliberalismo ante los derechos laborales

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    Carmen Añez

    2004-01-01

    Full Text Available Los derechos laborales son el punto central de la discusión política y social a escala mundial, de ahí su importancia de explorar la regulación de dichos derechos desde la óptica del Bienestar Social y del Neoliberalismo. Los resultados reflejan; que en el modelo de Bienestar Social, el Estado asume la regulación de los costos laborales, garantizando a los trabajadores una mejor calidad de vida y su reconocimiento como clase social, así como la reproducción del capital. El Estado se convierte en el sujeto social ordenador de las relaciones sociales y del mercado. Con el surgimiento de el Neoliberalismo se sustituyen las propuestas del Bienestar Social por nuevos patrones que agudizan los derechos de la clase trabajadora, generando la ruptura de las formas tradicionales de protección social. Se concluye, que los derechos laborales están en el centro de la estructura social, existiendo una tendencia hacia una variación no favorable en la regulación de los beneficios de la fuerza laboral, imponiéndose la flexibilización de las relaciones laborales y la privatización de la protección social, lo cual profundiza la inseguridad social, la precarización y la pobreza extrema.

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

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    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.

  2. The influence of social structure on brood survival and development in a socially polymorphic ant: insights from a cross-fostering experiment.

    Science.gov (United States)

    Purcell, Jessica; Chapuisat, M

    2012-11-01

    Animal societies vary in the number of breeders per group, which affects many socially and ecologically relevant traits. In several social insect species, including our study species Formica selysi, the presence of either one or multiple reproducing females per colony is generally associated with differences in a suite of traits such as the body size of individuals. However, the proximate mechanisms and ontogenetic processes generating such differences between social structures are poorly known. Here, we cross-fostered eggs originating from single-queen (= monogynous) or multiple-queen (= polygynous) colonies into experimental groups of workers from each social structure to investigate whether differences in offspring survival, development time and body size are shaped by the genotype and/or prefoster maternal effects present in the eggs, or by the social origin of the rearing workers. Eggs produced by polygynous queens were more likely to survive to adulthood than eggs from monogynous queens, regardless of the social origin of the rearing workers. However, brood from monogynous queens grew faster than brood from polygynous queens. The social origin of the rearing workers influenced the probability of brood survival, with workers from monogynous colonies rearing more brood to adulthood than workers from polygynous colonies. The social origin of eggs or rearing workers had no significant effect on the head size of the resulting workers in our standardized laboratory conditions. Overall, the social backgrounds of the parents and of the rearing workers appear to shape distinct survival and developmental traits of ant brood. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  3. La Pedagogía Social ante el proceso de convergencia europea de la Educación Superior.

    Directory of Open Access Journals (Sweden)

    José Antonio Caride Gómez

    2007-01-01

    Full Text Available En los inicios del siglo XXI las universidades europeas afrontan uno de sus procesos de reforma estructural y curricular más decisivos, con objetivos y líneas de actuación que tienen como principal soporte la Declaración de Bolonia (junio de 1999. Un documento con el que se propone crear un sistema de grados académicos fácilmente comprensibles y comparables, fomentar la movilidad de los estudiantes, docentes e investigadores, garantizar la calidad de la enseñanza y crear un Espacio Europeo de la Educación Superior (EEES. En este contexto, el artículo argumenta acerca de las connotaciones pedagógicas y sociales inherentes a estas reformas, valorando los principios y actuaciones en los que se sustentan como una nueva oportunidad para el reencuentro de las universidades consigo mismas y con la sociedad. También se analiza el estado de cuestión actual de la Pedagogía Social y de la Educación Social en España ante el proceso de convergencia, de sus realidades y desafíos en la construcción de una sociedad educadora, garante de los derechos cívicos y la condición ciudadana. Para concluir con una serie de recomendaciones y propuestas destinadas a mejorar las decisiones que se adoptan en el futuro, ante la previsible reconversión de la Diplomatura en Educación Social en un Grado con la misma denominación.  -------------------------------------------------------------------------- In the beginnings of the 21st century, European Universities confront one of the processes of structural and curricular reform more decisive, with aims and lines of action that take the Bologna Declaration as a principal support (June, 1999. A document that is designed to introduce a system of academic degrees that are easy to read and compare, to foment the mobility of students, teachers and researchers, to guarantee the quality in education and to take into account the European dimension of higher Education. In this context, the article argues about

  4. EL FORO SOCIAL MUNDIAL ANTE EL RETO DE LA EMANCIPACIÓN

    OpenAIRE

    Cartaya Fabregat, Raúl

    2012-01-01

    The current challenge of initiating processes of emancipation, confronted with the multifaceted capitalist reality extended throughout the globe and the strong depoliticization of our present day societies, appears to be an impossible task. Biopolitics and technologies of control are finding more and more fine-tuned and sophisticated mechanisms to both administrate and depoliticize. The World Social Forum, which presents itself as a social politicization model, emerged out of the rise in prot...

  5. 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

  6. LA ACCIÓN SOCIAL ANTE EL ABISMO DEL PERPETUO INICIAR: CON LA CIENCIA AL FONDO

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    Celso Sánchez Capdequí

    2011-01-01

    Full Text Available This paper considers the creative activity of human life. The Castoriadis’ Imaginary serves as support that explains this activity. The scientific process takes place in it. It is product of social imagination. This process explains the facts of the world but it must be explained too as a part of the experience.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Genetic differentiation between the ant Myrmica rubra and its microgynous social parasite

    DEFF Research Database (Denmark)

    Vepsäläinen, K.; Ebsen, J. R.; Savolainen, R.

    2009-01-01

    Hymenopteran inquiline species have been proposed to originate by sympatric speciation through intraspecific social parasitism. One such parasite, Myrmica microrubra, was recently synonymized with its Myrmica rubra host, because comparisons across Europe indicated insufficient genetic differentia......Hymenopteran inquiline species have been proposed to originate by sympatric speciation through intraspecific social parasitism. One such parasite, Myrmica microrubra, was recently synonymized with its Myrmica rubra host, because comparisons across Europe indicated insufficient genetic...... differentiation. Here, we use microsatellite markers to study genetic differentiation more precisely in a sample of Finnish M. rubra and its inquilines collected at two localities, supplemented with mitochondrial DNA sequences. The parasite had much lower genetic variation than the host at three of the four loci...

  9. 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...

  10. EL FORO SOCIAL MUNDIAL ANTE EL RETO DE LA EMANCIPACIÓN

    Directory of Open Access Journals (Sweden)

    Raúl Cartaya Fabregat

    2012-12-01

    Full Text Available The current challenge of initiating processes of emancipation, confronted with the multifaceted capitalist reality extended throughout the globe and the strong depoliticization of our present day societies, appears to be an impossible task. Biopolitics and technologies of control are finding more and more fine-tuned and sophisticated mechanisms to both administrate and depoliticize.The World  Social Forum, which presents itself as a social politicization model, emerged out of the rise in protests and criticisms that during the 90’s were made against despotism and the hegemony of the corporate and financial world. Since the beginning of the 21stCentury, the WSF has proposed the creation of a space for the counter-powers, a place to exchange, reflect and create a counter-hegemonic support network. However, even though the strong point of the Forum is found in its original structure, this appears  to be threatened by its global character, which in turn translates into its weakness.

  11. Dossiê: Trabajo Social y los desafíos ante de la custiòn Social

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    Olga Lucía Vélez Restrepo Lucía Vélez Restrepo

    2012-03-01

    Full Text Available

    Aunque son muchos los cambios y fracturas que el modelo de desarrollo neoliberal le han acarreado a la Custión Social en este articulo solo me ocuparé de aquellas situaciones generales que le plantean desplazamientos importantes a la profesión, buscando estimular una reflexión crítica sobre los desafíos que se le imponen al Trabajo Social contemporáneo. Los sentidos cambiantes de las prácticas sociales, la pérdida y la ruptura como estructuradoras de las sociedades contemporáneas, las situaciones de violencia política, social y familiar, el desplazamiento forzado, la violación a los derechos elementales, el desempleo y la exclusión, entre otros, le plantean al Travajo Social una serie de desafios en los ámbitos teórico, metodológico, investigativo, académico- formativo y organizacional.

  12. Increased Risk Proneness or Social Withdrawal? The Effects of Shortened Life Expectancy on the Expression of Rescue Behavior in Workers of the ant Formica cinerea (Hymenoptera: Formicidae).

    Science.gov (United States)

    Miler, Krzysztof; Symonowicz, Beata; Godzińska, Ewa J

    2017-01-01

    In social insects behavioral consequences of shortened life expectancy include, among others, increased risk proneness and social withdrawal. We investigated the impact of experimental shortening of life expectancy of foragers of the ant Formica cinerea achieved by their exposure to carbon dioxide on the expression of rescue behavior, risky pro-social behavior, tested by means of two bioassays during which a single worker (rescuer) was confronted with a nestmate (victim) attacked by a predator (antlion larva capture bioassay) or immobilized by an artificial snare (entrapment bioassay). Efficacy of carbon dioxide poisoning in shortening life expectancy was confirmed by the analysis of ant mortality. Rescue behavior observed during behavioral tests involved digging around the victim, transport of the sand covering the victim, pulling the limbs/antennae/mandibles of the victim, direct attack on the antlion (in antlion larva capture tests), and snare biting (in entrapment tests). The rate of occurrence of rescue behavior was lower in ants with shortened life expectancy, but that effect was significant only in the case of the entrapment bioassay. Similarly, only in the case of the entrapment bioassay ants with shortened life expectancy displayed rescue behavior after a longer latency and devoted less time to that behavior than ants from the control groups. Our results demonstrated that in ant workers shortened life expectancy may lead to reduced propensity for rescue behavior, most probably as an element of the social withdrawal syndrome that had already been described in several studies on behavior of moribund ants and honeybees.

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

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    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.

  14. A decomposição do Estado e o protagonismo da sociedade civil no enfrentamento da questão social no Brasil: os dilemas da cidadania e da democracia na contemporaneidade

    Directory of Open Access Journals (Sweden)

    Freire, Silene de Moraes

    2006-01-01

    Full Text Available O presente artigo foi elaborado a partir de preocupações profissionais voltadas para desvelar a presença e o enfrentamento, por parte do Estado e da sociedade civil, da questão social no cenário histórico-cultural da sociedade brasileira, evidenciado a partir da década de noventa, sobretudo, quando observamos a guinada do Estado brasileiro para a “mentalidade privatizante” que as reformas estruturais de cunho neoliberal promoveram. No caso brasileiro, tal projeto reafirma uma das particularidades de nossa cultura política: o moderno se constitui por meio do “arcaico”, recriando nossa herança histórica ao atualizar aspectos persistentes e, ao mesmo tempo, transformando-os no contexto da globalização. Pretendemos, assim, discutir de que modo a permanência histórica da desigualdade social, dos limites da cidadania e da democracia serviram como elemento facilitador para a implementação da agenda neoliberal no Brasil

  15. Los medios ante las catástrofes y crisis humanitarias: propuestas para una función social del periodismo

    OpenAIRE

    Toledano, S. (Samuel); Ardévol-Abreu, A. (Alberto)

    2013-01-01

    Los medios de comunicación deben desempeñar una función social, al servicio del público al que se dirigen. Esta labor es especialmente importante ante determinados acontecimientos de gran impacto social, como las catástrofes y las crisis humanitarias. En este estudio se llevó a cabo un análisis de códigos deontológicos, libros de estilo y otras herramientas de autorregulación, sin que hallaran recomendaciones específicas para la cobertura adecuada de estas situaciones. Un análisis...

  16. 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...

  17. 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

  18. 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.

  19. Las Agencias de Viajes ante la influencia de las Redes Sociales en el turismo. El caso de Ourense.

    Directory of Open Access Journals (Sweden)

    Laura Rodríguez Cid

    2015-01-01

    Full Text Available El modelo turístico tradicional ha experimentado un cambio con la llegada de las nuevas tecnologías. Las tradicionales herramientas de marketing empleadas por las Agencias de Viajes se están quedando atrás para dar paso a nuevos y mejorados métodos de comercialización y promoción de productos turísticos basados en la utilización de las Tecnologías de la Información y la Comunicación (TIC. Los hábitos de compra han cambiado debido a la rápida evolución de Internet en los últimos 10 años. Se ha pasado de la Web 1.0, de carácter estático y de lectura, a la Web 2.0 que ha generalizado la creación de contenidos y la comunicación on -line entre usuarios, convirtiéndose en creadores y a su vez en consumidores de la información. En los últimos años, las empresas turísticas han comenzado a crear canales de comercialización directos con el cliente, evitando así negociar con los intermediarios, lo que ha mejorado la eficiencia y la reducción de costes. Esto ha permitido que los usuarios puedan contratar un viaje o un servicio turístico a través de la red con unos costes notablemente inferiores. El asesoramiento que antes sólo se encontraba en las Agencias de Viajes, ahora es proporcionado por los usuarios que han consumido el servicio y cuya experiencia aporta una visión única y diferente. Todo este fenómeno ha ocasionado que este sector pase a un segundo plano, con un turista más experimentado, más exigente y familiarizado con estas nuevas herramientas nacidas de la Web 2.0. Numerosas agencias han cerrado sus negocios y tienden a desaparecer tal y como las conocemos actualmente. Sin embargo, son muchas las posibilidades que se les presentan si se adaptan al mercado actual, un entorno que fomenta el uso de las nuevas tecnologías y que utiliza la Web 2.0 y las Redes Sociales para mantener y captar nuevos clientes.

  20. 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.

  1. Formación del profesorado de ciencias sociales en educación secundaria ante el reto de la interculturalidad

    OpenAIRE

    Domínguez, M. Consuelo

    2006-01-01

    Esta investigación pretende profundizar en la formación del docente de ciencias sociales en educación secundaria ante el reto de la interculturalidad que viven nuestros centros educativos. Para ello, se ha trabajado con docentes de esta etapa elaborando un cuestionario ad hoc, con preguntas cerradas y abiertas; posteriormente, se han establecido grupos de discusión con un esquema de preguntas propuestas en función de las siete dimensiones de estudio, entregadas previamente a los docentes part...

  2. Evaluation of functional degeneration of the amazon-ant Polyergus rufescens Latr. under an influence of socially parasitic way of life.

    Science.gov (United States)

    Dobrzańska, J

    1978-01-01

    In certain, infrequently occurring, favorable circumstances the ants P. rufescens can display patterns of behavior which seem to be disappearing as a result of their parasitic way of life: the ability to food themselves, independently though ineffectively, elements of the offspring-protection behavior, transporting of nestmates, escape reaction. Similar events reinforce the infrequently used, latent reflexes, preventing their complete extinction. It is supposed that the characteristic in conventional parasitism disappearance of certain elements of behavior is inhibited by a social way of life. It may also be true of other, non-insect communities.

  3. Gênero e cotidiano escolar: dilemas e perspectivas da intervenção escolar na socialização afetivo-sexual dos adolescentes Gender and daily school: dilemmas and prospects of the school intervention in the affective-sexual socialization of adolescents

    Directory of Open Access Journals (Sweden)

    Rodrigo Pereira da Rocha Rosistolato

    2009-04-01

    Full Text Available Este artigo analisa as classificações de gênero utilizadas por professores que desenvolvem projetos de orientação sexual na cidade do Rio de Janeiro para explicar as perspectivas e os dilemas da intervenção escolar na socialização afetivo-sexual dos adolescentes. O material empírico que sustenta as argumentações é composto de 16 entrevistas em profundidade, realizadas com docentes responsáveis pelos espaços escolares onde se desenvolvem projetos de orientação sexual no ensino fundamental do Rio de Janeiro: os Núcleos de Adolescentes Multiplicadores (NAMs. Também foram realizadas "observações participantes" em um curso de formação para professores que desejam trabalhar com orientação sexual na escola. As representações de gênero apresentadas oscilam entre classificações modernas e tradicionais sobre a feminilidade e a masculinidade. Os projetos eram coordenados majoritariamente por professoras, e a participação discente também era basicamente feminina. As professoras buscavam coerência entre sua atuação nos espaços escolar e familiar. Porém, ao mesmo tempo que orientavam seus alunos para combater as desigualdades de gênero, apresentavam dúvidas e incertezas quanto à possibilidade de educar seus filhos a partir de ideais igualitários de gênero, principalmente os filhos homens. Situações domésticas contrastavam com performances em sala de aula, apresentando tensões entre negação e afirmação das masculinidades e feminilidades tradicionais.This article examines the classification of gender used by teachers who develop projects on sexual education in Rio de Janeiro to explain the views and the dilemmas of school intervention in the affective-sexual socialization of adolescents. The empirical material that supports the arguments is composed by 16 in-depth interviews, conducted with teachers responsible for school spaces where sexual education projects are developed in basic schools of Rio de Janeiro

  4. ESTETISISME DAN DILEMA PEMBERDAYAAN PEREMPUAN DALAM IKLAN

    Directory of Open Access Journals (Sweden)

    Moeljadi Pranata

    2001-01-01

    Full Text Available The development in women%5C%27s role is constructed by ads%5C%27 aestheticism and women%5C%27s attitude. Aestheticism provokes bad taste advertisement reducing woman as a mere biological object. Capitalistic system and structure has encouraged women to compete in social arena and subordination of women by men as well as conflicts among women. The empowerment of women%5C%27s role in ads can be achieved by generating the awareness on women not to part in stereotype establishing which inflicts women%5C%27s esteem. Further%2C law enforcement is required to control bad taste advertising. Abstract in Bahasa Indonesia : Perkembangan peran perempuan disebabkan oleh estetisisme iklan dan sikap perempuan sendiri. Estetisisme menyebabkan bad taste advertisement yang mereduksi perempuan sebatas mahluk biologis semata. Sistim dan struktur kapitalistik telah mendorong perempuan berkompetisi dalam arena sosial yang sekaligus menjadi ajang subordinasi perempuan oleh laki-laki serta ajang konflik antar perempuan. Pemberdayaan peran perempuan dalam iklan dapat dilakukan dengan gerakan penyadaran kepada perempuan agar tidak larut dalam proses pemapanan stereotipe yang merugikan perempuan. Selain itu%2C penegakan supremasi hukum perlu dilakukan untuk mengendalikan bad taste advertising. advertisment%2C+aestheticism%2C+empowerment%2C+women.

  5. 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...

  6. Associations of Two Ecologically Significant Social Insect Taxa in the Litter of an Amazonian Rainforest: Is There a Relationship between Ant and Termite Species Richness?

    Directory of Open Access Journals (Sweden)

    Amy L. Mertl

    2012-01-01

    Full Text Available In spite of the ecological dominance of Neotropical ants and termites, little is understood about how their interactions influence their species richness and distribution. We surveyed ground-dwelling termite and ant species in a primary rainforest in Ecuador and analyzed ecological correlates of diversity. Termite richness was positively correlated with ant richness and abundance of twig-nesting ants. We found no evidence of competition for twigs between termites and ants. No ecological factors were correlated with termite diversity although elevation and twig and log abundance influenced ant diversity. When ant richness was compared to the richness of termites employing different predator defenses, a positive correlation was found with soldierless termites, but not genera employing chemical or mechanical defense. Our results suggest that multiple ecological factors influence ant and termite diversity, and that ant predation on termites may have a greater effect than competition between ant and termites for nest sites and food sources.

  7. Social and genetic structure of a supercolonial weaver ant, Polyrhachis robsoni, with dimorphic queens

    DEFF Research Database (Denmark)

    Van Zweden, Jelle Stijn; Carew, Melissa E.; Henshaw, Michael T.

    2007-01-01

    We studied a population of the Australian weaver ant Polyrachis robsoni with regard to variation in the morphology of its winged queens using six newlydeveloped microsatellite markers. Morphometrically the queens fell clearly into two groups, macrogynes and microgynes, with the latter an isometri...... also significantly related and there was a weak inverse relationship between pairwise relatedness value between individuals and distance between nests.We conclude that this species is supercolonial and that the two queen morphs are part of the same population....

  8. A DNA and morphology based phylogenetic framework of the ant genus Lasius with hypotheses for the evolution of social parasitism and fungiculture

    Directory of Open Access Journals (Sweden)

    Stauffer Christian

    2008-08-01

    Full Text Available Abstract Background Ants of the genus Lasius are ecologically important and an important system for evolutionary research. Progress in evolutionary research has been hindered by the lack of a well-founded phylogeny of the subgenera, with three previous attempts disagreeing. Here we employed two mitochondrial genes (cytochrome c oxidase subunit I, 16S ribosomal RNA, comprising 1,265 bp, together with 64 morphological characters, to recover the phylogeny of Lasius by Bayesian and Maximum Parsimony inference after exploration of potential causes of phylogenetic distortion. We use the resulting framework to infer evolutionary pathways for social parasitism and fungiculture. Results We recovered two well supported major lineages. One includes Acanthomyops, Austrolasius, Chthonolasius, and Lasius pallitarsis, which we confirm to represent a seventh subgenus, the other clade contains Dendrolasius, and Lasius sensu stricto. The subgenus Cautolasius, displaying neither social parasitism nor fungiculture, probably belongs to the second clade, but its phylogenetic position is not resolved at the cutoff values of node support we apply. Possible causes for previous problems with reconstructing the Lasius phylogeny include use of other reconstruction techniques, possibly more prone to instabilities in some instances, and the inclusion of phylogenetically distorting characters. Conclusion By establishing an updated phylogenetic framework, our study provides the basis for a later formal taxonomic revision of subgenera and for studying the evolution of various ecologically and sociobiologically relevant traits of Lasius, although there is need for future studies to include nuclear genes and additional samples from the Nearctic. Both social parasitism and fungiculture evolved twice in Lasius, once in each major lineage, which opens up new opportunities for comparative analyses. The repeated evolution of social parasitism has been established for other groups of

  9. A DNA and morphology based phylogenetic framework of the ant genus Lasius with hypotheses for the evolution of social parasitism and fungiculture.

    Science.gov (United States)

    Maruyama, Munetoshi; Steiner, Florian M; Stauffer, Christian; Akino, Toshiharu; Crozier, Ross H; Schlick-Steiner, Birgit C

    2008-08-19

    Ants of the genus Lasius are ecologically important and an important system for evolutionary research. Progress in evolutionary research has been hindered by the lack of a well-founded phylogeny of the subgenera, with three previous attempts disagreeing. Here we employed two mitochondrial genes (cytochrome c oxidase subunit I, 16S ribosomal RNA), comprising 1,265 bp, together with 64 morphological characters, to recover the phylogeny of Lasius by Bayesian and Maximum Parsimony inference after exploration of potential causes of phylogenetic distortion. We use the resulting framework to infer evolutionary pathways for social parasitism and fungiculture. We recovered two well supported major lineages. One includes Acanthomyops, Austrolasius, Chthonolasius, and Lasius pallitarsis, which we confirm to represent a seventh subgenus, the other clade contains Dendrolasius, and Lasius sensu stricto. The subgenus Cautolasius, displaying neither social parasitism nor fungiculture, probably belongs to the second clade, but its phylogenetic position is not resolved at the cutoff values of node support we apply. Possible causes for previous problems with reconstructing the Lasius phylogeny include use of other reconstruction techniques, possibly more prone to instabilities in some instances, and the inclusion of phylogenetically distorting characters. By establishing an updated phylogenetic framework, our study provides the basis for a later formal taxonomic revision of subgenera and for studying the evolution of various ecologically and sociobiologically relevant traits of Lasius, although there is need for future studies to include nuclear genes and additional samples from the Nearctic. Both social parasitism and fungiculture evolved twice in Lasius, once in each major lineage, which opens up new opportunities for comparative analyses. The repeated evolution of social parasitism has been established for other groups of ants, though not for temporary social parasitism as found

  10. El padecimiento ante la enfermedad: Un enfoque desde la teoría de la representación social The experience of illness: An approximation from the theory of the social representation

    Directory of Open Access Journals (Sweden)

    César Hueso Montoro

    2006-03-01

    Full Text Available Los actuales modelos de gestión del cuidado proponen un acercamiento a los aspectos más subjetivos inherentes a la enfermedad, entendiendo esa subjetividad como un cúmulo de circunstancias históricas, sociales, culturales, etc, que condicionan la respuesta que la persona desarrolla ante la misma. Este artículo propone una reflexión sobre el fenómeno del padecimiento ante la enfermedad, articulando su argumento principal en torno a la teoría de las representaciones sociales de Moscovici. Los elementos que definen dicha teoría convierten al padecimiento en un fenómeno susceptible de ser abordado como una representación social, en tanto que constituye una fuente de significados individuales y colectivos que condicionan el modo en que un sujeto actúa y responde ante la enfermedad.Nowadays, the models of care management propose an approach to the most subjective aspects inherent in the illness, understanding this as an accumulation of cultural, social, historic circumstances, etc, which influence the answer that the person develops. This article proposes an analysis about the phenomenon of the experience of illness, articulating its main argument around the theory of the social representations of Moscovici. The elements of this theory convert the experience of illness in a susceptible phenomenon to be analyzed as a social representation, because constitutes a source of collective and individual meanings that influence the way in which the person acts and responds to illness.

  11. Thermoregulation strategies in ants in comparison to other social insects, with a focus on red wood ants (Formica rufa group [v2; ref status: indexed, http://f1000r.es/35p

    Directory of Open Access Journals (Sweden)

    Štěpánka Kadochová

    2014-03-01

    Full Text Available Temperature influences every aspect of ant biology, especially metabolic rate, growth and development. Maintenance of high inner nest temperature increases the rate of sexual brood development and thereby increases the colony fitness. Insect societies can achieve better thermoregulation than solitary insects due to the former’s ability to build large and elaborated nests and display complex behaviour. In ants and termites the upper part of the nest, the mound, often works as a solar collector and can also have an efficient ventilation system. Two thermoregulatory strategies could be applied. Firstly the ants use an increased thermal gradient available in the mound for brood relocation. Nurse workers move the brood according to the thermal gradients to ensure the ideal conditions for development. A precise perception of temperature and evolution of temperature preferences are needed to make the correct choices. A second thermoregulatory strategy used by mound nesting ants is keeping a high temperature inside large nests. The unique thermal and insulation properties of the nest material help to maintain stable conditions, which is the case of the Wood ant genus Formica. Ants can regulate thermal loss by moving nest aggregation and alternating nest ventilation. Metabolic heat produced by ant workers or associated micro organisms is an important additional source of heat which helps to maintain thermal homeostasis in the nest.

  12. 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 ...

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. Los criados salmantinos durante el siglo XVII (1601-1650: conflictividad social y actitudes ante la muerte

    Directory of Open Access Journals (Sweden)

    Francisco Javier LORENZO PINAR

    2011-03-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} A través de la documentación de los protocolos notariales y de los litigios del Archivo Histórico Diocesano, el presente artículo trata de aproximarnos a las situaciones conflictivas en las que se vieron envueltos los criados salmantinos en la primera mitad del siglo XVII (estupros, amancebamientos, pendencias, etc. así como sus actitudes ante la muerte y las relaciones que mantuvieron con sus amos y compañeros de trabajo reflejadas a través de los testamentos.

  18. AN UNUSUAL PATTERN OF GENE FLOW BETWEEN THE TWO SOCIAL FORMS OF THE FIRE ANT SOLENOPSIS INVICTA.

    Science.gov (United States)

    Ross, Kenneth G; Shoemaker, D DeWayne

    1993-10-01

    Uncertainty over the role of shifts in social behavior in the process of speciation in social insects has stimulated interest in determining the extent of gene flow between conspecific populations differing in colony social organization. Allele and genotype frequencies at 12 neutral polymorphic protein markers, as well as the numbers of alleles at the sex-determining locus (loci), are shown here to be consistent with significant ongoing gene flow between two geographically adjacent populations of Solenopsis invicta that differ in colony queen number. Data from a thirteenth protein marker that is under strong differential selection in the two social forms confirm that such gene flow occurs. Data from this selected locus, combined with knowledge of the reproductive biology of the two social forms, further suggest that interform gene flow is largely unidirectional and mediated through males only. This unusual pattern of gene flow results from the influence of the unique social enviroments of the two forms on the behavior of workers and on the reproductive physiology of sexuals. © 1993 The Society for the Study of Evolution.

  19. 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

  20. The genome of the leaf-cutting ant Acromyrmex echinatior suggests key adaptations to advanced social life and fungus farming

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Zhang, Guojie; Schiøtt, Morten

    2011-01-01

    ant-derived contribution to the fecal fluid, which otherwise consists of "garden manuring" fungal enzymes that are unaffected by ant digestion. The second is multiple mating of queens and ejaculate competition, which may be associated with a greatly expanded nardilysin-like peptidase gene family...

  1. GP-9s are ubiquitous proteins unlikely involved in olfactory mediation of social organization in the red imported fire ant, Solenopsis invicta.

    Directory of Open Access Journals (Sweden)

    Walter S Leal

    Full Text Available The red imported fire ant (RIFA, Solenopsis invicta, is an invasive species, accidentally introduced in the United States that can cause painful (sometimes life-threatening stings to human, pets, and livestock. Their colonies have two social forms: monogyne and polygyne that have a single and multiple functional queens, respectively. A major gene (Gp-9, identified as a putative pheromone-binding protein on the basis of a modest amino acid sequence identity, has been suggested to influence the expression of colony social organization. Monogyne queens are reported to possess only the GP-9B alleles, whereas polygyne queens possess both GP-9B and GP-9b. Thus, both social forms are reported to express GP-9B, with GP-9b being a marker expressed in polygynes but it is absent in monogynes. Here, we report two types of polygyne colonies, one that does not express GP-9b (monogyne-like and the other expressing both proteins, GP-9B and GP-9b. Given their expression pattern, GP-9s are hemolymph proteins, which are more likely to be involved in the transport of lipids and small ligands within the homocoel. GP-9B existed in two forms, one of them is phosphorylated. The helical-rich content of the protein resembles the secondary structures of a beetle hemolymph protein and moth pheromone-binding proteins. An olfactory role is unlikely given the lack of specific expression in the sensillar lymph. In marked contrast to GP-9s, a chemosensory protein, SinvCSP, is demonstrated to be specifically expressed in the antennae. Within the antennae, expression of SinvCSP is restricted to the last two segments, which are known to house olfactory sensilla.

  2. 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

  3. El educador social ante el maltrato infantil: Fuentes de información y rol profesional. Un estudio documental

    Directory of Open Access Journals (Sweden)

    Jesús VALVERDE BERROCOSO

    2009-11-01

    Full Text Available RESUMEN: El maltrato infantil es un problema social muy grave hoy en día. El abuso en la infancia es, además, un problema multidimensional: médico, psicológico, económico y cultural. El presente artículo aboga por la necesidad de solucionar este grave problema desde un enfoque educativo. En este contexto, el Educador Social es un nuevo profesional que tiene que desempeñar un papel relevante en este asunto y, por ello, este artículo define algunas de sus posibles funciones de carácter, fundamentalmente, preventivo. Por otro lado, el autor cree que un profesional competente es aquel que sabe procesar la información. La informática y, en particular, la tecnología CD-ROM, nos permite acceder a bases de datos de todo el mundo. Aquí se hace un estudio bibliográfico a partir de la base de datos ERIC, especializada en temas educativos, y se recogen las principales fuentes de información que todo Educador Social debe manejar para enfrentarse con más eficacia al maltrato de la infancia.SUMMARY: Child maltreatment is a very serious social problem nowadays. Child abuse is, besides, a multidimensional problem: medical, psychological, economic and cultural. The present article advocates an educational approach to solve this grave problem. In this context, the Social Educator is a new professional who has to carry out a relevant role about this subject and, for this reason, the article defines some preventive functions. On the other hand, the author thinks a competitive professional is one who knows how to process information. Computer science and, particulary, CD-ROM technology, allows access to bibliography around the world. This is a bibliographic study that it is based on ERIC (Educational Resources Information Center and it collects those principal sources of information that any Social Educator must know to efficiently face child maltreatment.

  4. 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

  5. Testing the adjustable threshold model for intruder recognition on Myrmica ants in the context of a social parasite

    DEFF Research Database (Denmark)

    Fürst, Matthias Alois; Durey, Maëlle; Nash, David Richard

    2012-01-01

    gains access to the ants' nests by mimicking their cuticular hydrocarbon recognition cues, which allows the parasites to blend in with their host ants. Myrmica rubra may be particularly susceptible to exploitation in this fashion as it has large, polydomous colonies with many queens and a very viscous...... and therefore the less-related workers within a colony, the less aggressively they will behave; and that colonies facing parasitism will be more aggressive than colonies experiencing less parasite pressure. Our results confirm all these predictions, supporting flexible aggression behaviour in Myrmica ants...

  6. EL PROGRAMA DE CONOCIMIENTO DEL MEDIO NATURAL, SOCIAL Y CULTURAL ANTE EL ESPACIO EUROPEO DE EDUCACION SUPERIOR

    Directory of Open Access Journals (Sweden)

    Alicia Benarroch Benarroch

    2004-06-01

    Full Text Available En el proceso de convergencia europea, las universidades andaluzas han alcanzado un acuerdo para la materia de Conocimiento del Medio Natural, Social y Cultural en la Titulación de Maestro: especialidad de Educación Física y en la Titulación de Maestro: especialidad de Educación Musical. En este trabajo se pretende conocer si estos programas realmente tratan de representar los de las distintas universidades. Tras un análisis exhaustivo de los contenidos de los respectivos programas, se demuestra que no existe ni ese consenso ni criterios justificados que avalen las propuestas realizadas. Finalmente, se hace una apuesta por un programa específico, por ser el que mejor representa el criterio de convencionalidad y consenso de la comunidad científica andaluza.

  7. 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.

  8. 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.

  9. Imported fire ants near the edge of their range: disturbance and moisture determine prevalence and impact of an invasive social insect.

    Science.gov (United States)

    LeBrun, Edward G; Plowes, Robert M; Gilbert, Lawrence E

    2012-07-01

    1. Habitat disturbance and species invasions interact in natural systems, making it difficult to isolate the primary cause of ecosystem degradation. A general understanding requires case studies of how disturbance and invasion interact across a variety of ecosystem - invasive species combinations. 2. Dramatic losses in ant diversity followed the invasion of central Texas by red imported fire ants (Solenopsis invicta). However, recent manipulative studies in Florida revealed no effect on ant diversity following the removal of S. invicta from a disturbed pasture habitat, but moderate loss of diversity associated with their introduction into undisturbed habitat and no invasion occurred without disturbance. Thus, the importance of S. invicta in driving diversity loss and its ability to invade undisturbed systems is unresolved. 3. We examine the distribution and abundance of a large monogyne S. invicta population and its association with the co-occurring ant assemblage at a site in south Texas close to the aridity tolerance limit of S. invicta. 4. We document that moisture modulates S. invicta densities. Further, soil disturbing habitat manipulations greatly increase S. invicta population densities. However, S. invicta penetrates all habitats regardless of soil disturbance history. In contrast, controlled burns depress S. invicta densities. 5. In habitats where S. invicta is prevalent, it completely replaces native fire ants. However, S. invicta impacts native ants as a whole less strongly. Intriguingly, native ants responded distinctly to S. invicta in different environments. In wet, undisturbed environments, high S. invicta abundance disrupts the spatial structure of the ant assemblage by increasing clumping and is associated with reduced species density, while in dry-disturbed habitats, sites with high S. invicta abundance possess high numbers of native species. Analyses of co-occurrence indicate that reduced species density in wet

  10. 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.

  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. Comercializando fantasias: a representação social da prostituição, dilemas da profissão e a construção da cidadania Commercializing fantasies: social representations of prostitution, dilemmas of the profession and the construction of citizenship

    Directory of Open Access Journals (Sweden)

    Katia Guimarães

    2005-12-01

    Full Text Available O presente artigo discute fatos, percepções e representações sociais do cotidiano das mulheres profissionais do sexo (MPS. Foram avaliados oito projetos de intervenção educativa sobre DST/Aids dirigidos a MPS, em cidades das regiões Sul, Nordeste e Sudeste. Foram realizadas entrevistas em profundidade e grupos focais. Os resultados revelaram que a representação da mulher que vende o corpo vem sendo re-significada para a realização de fantasias eróticas. As perspectivas de maior autonomia da profissão contrastam com a discriminação e a pressão psicológica. Foi mencionada a violência, praticada por clientes e policiais. Foram evidentes a importância do preservativo na negociação dos programas e o não-uso do mesmo em relações com envolvimento afetivo ou devido à concorrência. Conclui-se, sob a ótica da autonomia, que classe social, escolaridade, situação de crise econômica e estigma ocasionam discriminação, violência e risco de contágio de DST e HIV.This article presents facts, perceptions and social representations on the daily life of female commercial sex workers (FCSW. We evaluated 8 educational intervention programs on STD/AIDS addressed to FCSW in cities of southern, south-eastern and north-eastern Brazilian regions. In those places, we conducted in-depth interviews and focal groups. Results indicate that the representation of a woman who sells her body is resignified as the performance of erotic fantasies. Possibilities of greater autonomy are hampered by discrimination and psychological tension. Client and police-driven violence were remarkable. Condom use plays a relevant role in sex negotiation but it is neglected when relationships involve affection or as a result of competition. We conclude, from the perspective of autonomy, that FCSW's autonomy is limited by social class, economical crisis and stigma, leading to discrimination, violence and STD/HIV contagion risk.

  13. 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...

  14. 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....

  15. 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

  16. EL CONTRATO SOCIAL DEL MÉDICO ANTE EL DESASTRE DE LA SALUD Pronunciamiento de la Academia Nacional de Medicina 9 de mayo de 2011

    Directory of Open Access Journals (Sweden)

    Academia Nacional de Medicina

    2011-04-01

    Full Text Available

    Con el advenimiento de la atención “gerenciada” de la salud (managed care que implantó en Colombia la Ley 100 de diciembre 23 de 1993 se ha pretendido modificar el contrato social del médico, sustituir el imperativo hipocrático de considerar ante todo el bien del paciente por una pretendida “justicia distributiva” que ha llevado a Colombia al actual desastre en el sistema de atención de la salud. Economistas de la llamada escuela neoliberal que preconizan la privatización con ánimo de lucro y la mano invisible del mercado como los factores supremos de desarrollo y regulación y propenden por el debilitamiento del Estado y de las instituciones de carácter público, han manejado directa o indirectamente el sistema de salud. Esto tal vez ilustra lo inexplicable: a los 17 años de la creación del Sistema General de Seguridad Social en Salud (SGSSS todavía no existe un sistema de información con registro único, y la Superintendencia Nacional de Salud es extremadamente débil y continúa adscrita al Ministerio de la Protección Social, dando amplio campo de acción a las aseguradoras, que más bien son intermediarios financieros. Se debe tener en cuenta que un sistema de salud es, en esencia, un sistema de información, y que al crear el mercado de la salud se requerían mecanismos de vigilancia y control muy fuertes. Ni sistema de información, ni adecuada vigilancia, ni estricto control ha tenido el actual sistema de salud colombiano. Sin embargo, la Academia Nacional de Medicina, por ley órgano consultor del Gobierno, ha advertido repetidamente tales fallas desde hace años.

    El modelo de la atención “gerenciada” de la salud significa un cambio profundo en uno de los pilares de la estructura de la sociedad, el de la atención de la salud, y altera en forma dramática tanto el ejercicio de la medicina como la esencia misma de la profesión, con detrimento de la calidad de la atención. En efecto, el modelo

  17. 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

  18. 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.

  19. Modelo de intervención social sostenible para mejorar la salud infantil ante el efecto de la parasitosis intestinal en el Centro Poblado Pacherrez, Lambayeque, Perú, 2008-2009

    OpenAIRE

    Malca Tello, Nancy Llalud

    2011-01-01

    Problema científico: La presencia de helmintos parásitos en niños es crónico en pueblos rurales, debido a que sólo se aplican programas para aliviar la salud infantil, por lo que se plantea la interrogante ¿Cómo influye un modelo de intervención social sostenible para mejorar la salud infantil ante el efecto de la parasitosis intestinal en el Centro Poblado de Pacherrez del Distrito de Pucalá en la Provincia de Chiclayo, Departamento de Lambayeque-Perú, durante 2008 y 2009? Hipótesis: La apli...

  20. 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.

  1. 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.

  2. 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...

  3. Tinjauan Kritis Terhadap Teori Aktivitas dan Dilema Sosial

    Directory of Open Access Journals (Sweden)

    Juneman Juneman

    2011-04-01

    Full Text Available Nowadays, there are developing theories in social psychology. Two of them are activity and social dilemma theory. Unfortunately, Indonesia has less expertise in specific theoretical social psychology. The article is purposed to give analysis for the two theories including its history, its development today, and also its research critical and prospect in the future. This description could help academics and practitioners to build and develop best theories (as well as practice in their own environment. Based on the critical analysis, it could be concluded that along with their advantages and limits, both activity and social dilemma theory are prospective in triggering researches especially in Indonesia, where there are not much research using those theories. 

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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

    Directory of Open Access Journals (Sweden)

    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.

  12. Identifying the Transition between Single and Multiple Mating of Queens in Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R.

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...

  13. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...

  14. ¿El fin de la naturaleza? Paradojas sociales de la idea moderna de libertad

    Directory of Open Access Journals (Sweden)

    Maynor A. Mora Alvarado

    2010-03-01

    Full Text Available Resumen: Se estudian los principales problemas que presenta la concepción moderna de libertad frente a la naturaleza. Primero, surge el problema de la liberación respecto del mundo objetivo, la cual trae aparejado la destrucción del entorno y el cuestionamiento de la viabilidad de la especie. Segundo, se presenta el problema de la complejizacion de lo social, frente al que sucumbe, en gran medida, el tema de la liberación política. Se concluye con la búsqueda de algunas alternativas ante estos dilemas. Abstract The article analyzes the problems posed by the modern conception of freedom before nature. The first to arise is the problem posed by the modern conception of freedom before nature. The first to arise is the problem of the emancipation from the objective world which brings along the destruction of the environment and the questioning about the viability of the species. The second problem is the complex character of the social life before whom succumbs, largely the issue of political emancipation. The article concludes which the search of some alternatives to these dilemmas.

  15. 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 ...

  16. 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.

  17. 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.

  18. 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, ...

  19. "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...

  20. 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

  1. Envelhecimento populacional, cuidado e cidadania: velhos dilemas e novos desafios

    Directory of Open Access Journals (Sweden)

    Berlindes Astrid Küchemann

    2012-04-01

    Full Text Available O Brasil é um país que envelhece a passos largos. Em 2011, a população idosa era de 20,5 milhões, o equivalente a 10,8% da população total. Projeções indicam que, em 2020, a população idosa brasileira será de 30,9 milhões, representando 14% da população total. Esse envelhecimento acelerado vem produzindo necessidades e demandas sociais que requerem respostas políticas adequadas do estado e da sociedade. Dentre os inúmeros desafios a serem enfrentados está a questão do cuidado. As políticas públicas de amparo aos/às idosos/as consideram a família, o estado e a sociedade igualmente responsáveis pelo cuidado. Na prática, o mesmo tem sido visto como uma questão privada e não pública, cabendo, sobretudo, à família, materializada na figura da mulher, a tarefa de cuidar dos/as idosos/as. Este trabalho tem por objetivo, mostrar o quão inadequado é esse modelo que elege as mulheres como únicas responsáveis pelo cuidado e explora as possibilidades de um modelo que permita um envelhecimento com cidadania, no qual atuem família, estado e outros atores da sociedade.Brazil is a country that ages increasingly. In 2011, the elderly population marks 20,5 million, equivalent to 10,8% of the entire population. Projections suggest that, in 2020, the elderly Brazilian population will be 30,9 million, representing 14% of the whole population. This fast growing of the elderly population requires social services and demands appropriate political answers from both, the state and society. Among the many challenges to be faced is the one of the care services. The public policies for the elderly consider the family, the state and the society equally responsible for the care. In practical terms, this matter has been seen as a private and not a public issue, materializing in the figure of the woman, the job of looking after the elderly. The objective of this paper is to show how inadequate this model that elects women as the only

  2. 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

  3. 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...

  4. 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 ...

  5. 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.

  6. 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.

  7. 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...

  8. 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...

  9. 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

  10. 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.

  11. Evaluation Toolbox: Ex-Ante Impact Assessment and Value Network Analysis for SI

    NARCIS (Netherlands)

    Dhondt, S.; Ven, H. van de; Cressey, P.; Kaderabkova, A.; Luna, Á.; Moghadam Saman, S.; Castro Spila, J.; Ziauberyte, R.; Torre, W. van der; Terstriep, J.

    2016-01-01

    This report contains a toolbox for use with the Ex-Ante Impact Assessment for social innovations as was developed in the report D7.1. This toolbox proposes a series of convenient and useful tools to apply in an ex-ante assessment of social innovation within SIMPACT's policy areas unemployment,

  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. 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.

  14. 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.

  15. 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

  16. 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...

  17. Amenazas naturales y evaluación subjetiva en la construcción de la vulnerabilidad social ante desastres naturales en Chile y Brasil

    Directory of Open Access Journals (Sweden)

    Hugo Romero

    2012-07-01

    Full Text Available http://dx.doi.org/10.5007/1807-1384.2012v9n1p127   Se analiza desde los puntos de vista objetivo y subjetivo,  algunos de los factores económicos, políticos, sociales y culturales que han participado de la construcción de la vulnerabilidad social con que, comunidades de Chile y Brasil, han enfrentado desastres naturales recientes, que han incluido inundaciones, remociones en masa de sedimentos, terremotos y tsunamis. Factores globales han generado restricciones económicas que se han manifestado localmente en un aumento de la vulnerabilidad social debido a la falta de inversiones públicas  en obras de protección. Adicionalmente, se han observado procesos de exclusión y segregación social, traducidos en una ocupación humana permanente y sistemática de áreas expuestas a las amenazas naturales, en las cuáles se ha ubicado a la población de menores recursos. Las percepciones de los riesgos naturales, las formas de organización social y las expectativas y frustraciones de las comunidades locales constituyen valiosas lecciones que deberían ser las bases del aprendizaje social necesario para evitar que estas tragedias continúen repitiéndose en nuestros países.

  18. The diversity of microorganisms associated with Acromyrmex leafcutter ants

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. 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...

  1. 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...

  2. Amenazas naturales y evaluación subjetiva en la construcción de la vulnerabilidad social ante desastres naturales en Chile y Brasil

    OpenAIRE

    Hugo Romero; Magaly Mendonça

    2012-01-01

    http://dx.doi.org/10.5007/1807-1384.2012v9n1p127   Se analiza desde los puntos de vista objetivo y subjetivo,  algunos de los factores económicos, políticos, sociales y culturales que han participado de la construcción de la vulnerabilidad social con que, comunidades de Chile y Brasil, han enfrentado desastres naturales recientes, que han incluido inundaciones, remociones en masa de sedimentos, terremotos y tsunamis. Factores globales han generado restricciones económicas que se han m...

  3. 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.

  4. Análisis de las metodologías de evaluación ex ante de Proyectos aplicados en los programas sociales en el Distrito Capital (2004-2008

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    Ramón Hernán Bojacá Martín

    2007-06-01

    Full Text Available El propósito de esta investigación, es el análisis y evaluación de las metodologías implementadas por el Distrito Capital para implementar los llamados "proyectos sociales" con el fin de establecer la influencia de la metodología en los resultados obtenidos de dichos proyectos. Para ello se hizo una selección de los proyectos asignados a la inversión y al gasto social a partir de las fichas EBI (Estadísticas Básicas de Información. Su análisis y evaluación se realizó con base en las reglas teóricas estándar de la Evaluación Ex Ante, definidas en los Manuales de uso frecuente por parte de las Entidades Multilaterales y Oficiales que aprueban dichos proyectos y asignan los recursos para su ejecución. De acuerdo con las 14 variables especificadas para que el proyecto cumpla con los parámetros definidos en el estándar, se encontró que casi todos los proyectos analizados adolecen de diagnósticos operativos de la situación sobre la que se quiere trabajar, no hay precisión ni se priorizan los objetivos en relación con las políticas sociales las inversiones, los costos y su factibilidad. Igualmente, se encontró que los proyectos no contemplan componentes que midan los impactos o indicadores que muestren el mejoramiento de la calidad de vida de las personas a quienes van orientados.

  5. Heat-induced symmetry breaking in ant (Hymenoptera: Formicidae escape behavior.

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    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.

  6. 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.

  7. 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...

  8. Orientaciones y paradojas del papel de la universidad pública ante los desafíos sociales y políticos de México

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    José Antonio Ramírez Díaz

    2016-04-01

    Full Text Available El presente texto, examina el papel definido a la universidad en los instrumentos de política pública en México. En el momento que afronta el reto de identificar el impacto de problemas sociales como la violencia, la pobreza, la desigualdad y la emergencia de nuevos desafíos políticos como son la ingobernabilidad en entidades federativas y el descrédito a los procesos electorales y a los órganos políticos. El núcleo de la reflexión es la pertinencia de los diagnósticos y las estrategias de atención elaboradas en los planes y programas de los gobiernos federal y estatal que definen su papel como institución. Palabras clave: educación superior; política educativa; política social.

  9. La categoría de lebenswelt en Jürgen Habermas y sus dificultades ante el diálogo social intercultural.

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    Iván Raimundo Canales Valenzuela

    2009-07-01

    Full Text Available Se observa en el continente latinoamericano una recepción del pensamiento habermasiano en la dirección de querer pensar desde él problemas de integración social inherentes a las problemáticas de desigualdad social y política de nuestros pueblos. Nuestra convicción es que a partir del problematismo de la categoría de Lebenswelt, entre otras, dicha empresa no es factible pues hemos podido mostrar importantes exclusiones categoriales en el núcleo duro (heurística negativa de la teoría de acción comunicativa de Habermas. Esta es la tesis que pretendemos defender en este artículo.

  10. La educación de posgrado como necesidad social. Tendencias y retos ante la Universidad Latinoamericana contemporánea

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    Lic. Yusimi Cuéllar Contreras

    2016-06-01

    Full Text Available La formación de postgrado se caracteriza por ser uno de los procesos consubstanciales a la Universidad, considerada ésta como la institución social que preserva y desarrolla la cultura de la sociedad. Estos y otros factores que podrían incluirse, marcan un considerable reto a las instituciones de Educación Superior en relación con la calidad del postgrado y particularmente a los profesores que los imparten y profesionales que participan. En este artículo se hace referencia al papel de la Universidad como institución social, además se abordan aspectos como las tendencias, retos y desafíos a los cuales se enfrenta la Universidad Latinoamericana contemporánea en cuanto a la educación de postgrado, haciendo énfasis en el contexto cubano.

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

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    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

  12. 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....

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

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    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.

  14. Los dilemas morales en la filosofía analítica

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    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.

  15. 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.

  16. Dificultades y dilemas de la política de inmigración

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    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.

  17. 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.

  18. O julgamento moral de dilemas éticos em negociação

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    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.

  19. Thermoregulation strategies in ants in comparison to other social insects, with a focus on Formica rufa [v1; ref status: indexed, http://f1000r.es/2fv

    Directory of Open Access Journals (Sweden)

    Štěpánka Kadochová

    2013-12-01

    Full Text Available Temperature influences every aspect of ant biology, especially metabolic rate, growth and development. Maintenance of high inner nest temperature increases the rate of sexual brood development and thereby increases the colony fitness. Insect societies can achieve better thermoregulation than solitary insects due to the former’s ability to build large and elaborated nests and display complex behaviour. In ants and termites the upper part of the nest, the mound, often works as a solar collector and can also have an efficient ventilation system. Two thermoregulatory strategies could be applied. Firstly the ants use an increased thermal gradient available in the mound for brood relocation. Nurse workers move the brood according to the thermal gradients to ensure the ideal conditions for development. A precise perception of temperature and evolution of temperature preferences are needed to make the correct choices. A second thermoregulatory strategy used by mound nesting ants is keeping a high temperature inside large nests. The unique thermal and insulation properties of the nest material help to maintain stable conditions, which is the case of the Wood ant genus Formica. Ants can regulate thermal loss by moving nest aggregation and alternating nest ventilation. Metabolic heat produced by ant workers or associated micro organisms is an important additional source of heat which helps to maintain thermal homeostasis in the nest.

  20. 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.

  1. 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.

  2. La Formación Profesional ante los derechos humanos: cualificaciones asociadas a la Educación Social en España y Alemania

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    Miguel Ángel Rodríguez Fernández

    2017-01-01

    Full Text Available La formación para el trabajo juega en la promoción de los derechos humanos y laborales un papel protagonista, debido a su condición habilitadora para el ejercicio profesional. Sin embargo, ha sido despojada, en ocasiones de manera intencionada, de esta dimensión humanista, escapando a dicho objetivo, que constituye un compromiso innegociable en la sociedad de la precariedad, la incertidumbre y la modernidad líquida. La Educación Social se vincula, así, con la formación profesional desde un punto de vista epistemológico y profesional, por lo que abordaremos las posibilidades de la pedagogía social en su vertiente profesionalizadora en los contextos alemán y español. Maike Masemann es investigadora asociada en la Universidad Carl von Ossietzky de Oldenburg, Alemania. Tras formarse como empleada de banca y asesora financiera en el sistema de formación profesional dual alemán, ha desarrollado su profesión durante varios años en diversas empresas del sector. Posteriormente cursó el grado universitario de Estudios profesionales y Educación Económica y el Master en Educación, y desde 2013 desarrolla su trabajo como investigadora en la mencionada Universidad. Sus principales áreas de estudio son la psicología educativa, la formación continua en el contexto empresarial y la academización, entendida como el fenómeno de aproximación que se da actualmente entre la formación profesional y académica en el contexto alemán.

  3. 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.

  4. Ex-Ante Impact Assessment & Value Network Analysis for SI: SIMPACT Working Paper 2

    NARCIS (Netherlands)

    Dhondt, S.; Ven, H. van de; Ziauberyte, R.; Torre, W. van der; Cressey, P.; Kaderabkova, A.; Luna, Á.; Moghadam Saman, S.; Castro Spila, J.; Terstriep, J.

    2016-01-01

    In this paper, a conceptual framework is presented to conduct an ex-ante impact assessment for social innovation. The building blocks for an ex-ante impact assessment are goal formulation; developing the relationships between inputs, outputs and outcomes; determining the role of stakeholders to

  5. Ex-Ante Impact Assessment & Value Network Analysis for SI: Report Task 7.1

    NARCIS (Netherlands)

    Dhondt, S.; Ven, H. van de; Ziauberyte, R.; Torre, W. van der; Cressey, P.; Kaderabkova, A.; Luna, Á.; Moghadam Saman, S.; Castro Spila, J.; Terstriep, J.

    2016-01-01

    In this report, a conceptual framework is presented to conduct an ex-ante impact assessment for social innovation. The building blocks for an ex-ante impact assessment are goal formulation; developing the relationships between inputs, outputs and outcomes; determining the role of stakeholders to

  6. Ex-Ante Impact Assessment & Value Network Analysis for SI: SIMPACT Policy Brief 1

    NARCIS (Netherlands)

    Dhondt, S.; Ven, H. van de; Cressey, P.; Kaderabkova, A.; Luna, Á.; Moghadam Saman, S.; Castro Spila, J.; Terstriep, J.

    2016-01-01

    In this Policy Brief, a conceptual framework is presented to conduct an ex-ante impact assessment for social innovation. The building blocks for an ex-ante impact assessment are goal formulation; developing the relationships between inputs, outputs and outcomes; determining the role of stakeholders

  7. Evolutionary transition from single to multiple mating in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, P.; Gertsch, Pia J.; Frydenberg, J.

    1999-01-01

    Queens of leafcutter ants exhibit the highest known levels of multiple mating (up to 10 mates per queen) among ants. Multiple mating may have been selected to increase genetic diversity among nestmate workers, which is hypothesized to be critical in social systems with large, long-lived colonies ...

  8. 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.

  9. 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

  10. 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

  11. 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].

  12. La ciudadanía como ámbito de integración social ante el fenómeno de las migraciones

    Directory of Open Access Journals (Sweden)

    Santamarina, Cristina

    2010-08-01

    Full Text Available One can only begin to understand immigration through conflict with others, with that which is different and, therefore, as a complex experience for all cultures. We cannot expect these conflicts to be resolved in the uncertain sphere of society or transfer them to the administration. Citizens form the only institution truly capable of accommodating this new reality striking down like a new challenge for European societies. That is because we, the citizens, accept the rights and duties inherent to our institution, and we can even extend this proposal to other peoples, to peoples with their own baggage, cultures and experiences given they are willing to assume these same rights and duties.

    El impacto de la inmigración no puede comprenderse más que desde el conflicto del encuentro con los otros, con lo otro diferente y, por tanto, como experiencia compleja para toda cultura. No podemos tampoco esperar que esos conflictos se resuelvan en el incierto espacio de lo social ni transferir a las administraciones esta responsabilidad. La institución de la ciudadanía es la única con capacidad verdadera para acoger esta nueva realidad que golpea como un nuevo desafío a las sociedades de Europa. Porque la ciudadanía es la institución en la que aceptamos los derechos y los deberes de la pertenencia y desde la cual es posible ampliar dicha propuesta a otros, con otros bagajes, culturas y experiencias, que estén dispuestos a asumir con nosotros, esos mismos derechos y deberes.

  13. 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...

  14. Consideraciones bioético-sociales en pacientes geriátricos y ancianos frágiles Bioethic and social considerations on geriatric patients and fragile elderlies

    Directory of Open Access Journals (Sweden)

    Raúl Padrón Chacón

    2008-12-01

    Full Text Available Se procedió a la revisión de fuentes bibliográficas relacionadas, no solo con el estado actual del envejecimiento en otras latitudes, sino también en Cuba, así como consideraciones bioético-sociales en pacientes de la tercera edad en estado terminal. Se enfatizó en el concepto de estado vegetativo persistente y muerte encefálica aplicado en nuestro país, al igual que los dilemas que existen desde el punto de vista ético entre unos y otros cuidados actualmente. Los cuidados paliativos al geronto-geriátrico, los dilemas y su aplicación a ancianos frágiles constituyen la motivación de este trabajo.The bibliographical sources related not only with the present state of aging in other latitudes, but also in Cuba, as well some bioethical and social considerations on elderly patients at the terminal stage of life were reiewed. Emphasis was made on the concept of persistent vegetative state and encephalic death applied in our country, and on the dilemas existing from the ethical point of view between one care and the other at present. The palliative care of the elderly, the dilemas and their application to fragile elderlies are the motivation of this work.

  15. 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

  16. 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

  17. 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

  18. 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

  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. TEORÍA, CAMBIO SOCIAL Y DESARROLLO

    Directory of Open Access Journals (Sweden)

    Jairo Puentes Palencia

    2002-01-01

    Full Text Available Se exponen las principales tendencias del pensamiento social en América Latina a lo largo del siglo XX. El punto de partida es la conceptualización de la región, que va más allá de la delimitación histórico-geográfica, lo cual permite plantear la herencia histórica. Las concepciones del pensamiento social y de la sociología se pueden diferenciar a lo largo del siglo XX a través de tres etapas: la etapa de los "pensadores", la sociología "cientifista" y la sociología "crítica". A partir de las concepciones clásicas sobre el desarrollo surgen expresiones latinoamericanas sobre el mismo, a través de la escuela de cepalina, con sus posteriores desarrollos del estructuralismo, los planteamientos del marxismo ortodoxo y, en particular, la escuela de la dependencia. Otra escuela o enfoque, que si bien tiene su origen en los clásicos y se adapta a las condiciones de la región, es la teoría de la modernización, en la práctica del desarrollismo en sus componentes económico, social y político. A finales de los años ochenta y comienzos de los noventa, el sistema mundial adopta nuevas características: de la bipolaridad se pasa a la unipolaridad y/o globalización, lo cual deja "sin piso" escuelas como las de la dependencia y otros planteamientos radicales de izquierda. Ante el fracaso de la modernidad, o de algunas de sus promesas, América Latina se ve abocada al mundo de la globalización y, al mismo tiempo, al dilema mundial que busca el desarrollo social a través de dos grandes paradigmas: la globalización neoliberal o la globalización democrática, lo que significa un nuevo reto para la construcción de un pensamiento latinoamericano y para el siglo XXI.

  2. 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...

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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...

  8. 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...

  9. Ex-Ante Impact Assessment & Value Network Analysis for SI: Report Task 7.1

    OpenAIRE

    Dhondt, S.; Ven, H. van de; Ziauberyte, R.; Torre, W. van der; Cressey, P.; Kaderabkova, A.; Luna, Á.; Moghadam Saman, S.; Castro Spila, J.; Terstriep, J.

    2016-01-01

    In this report, a conceptual framework is presented to conduct an ex-ante impact assessment for social innovation. The building blocks for an ex-ante impact assessment are goal formulation; developing the relationships between inputs, outputs and outcomes; determining the role of stakeholders to achieve the objectives; calculating the impact; and deciding on the social innovation. These building blocks are sequentially interconnected to each other. In conclusion, our conceptual framework aims...

  10. Ex-Ante Impact Assessment & Value Network Analysis for SI: SIMPACT Policy Brief 1

    OpenAIRE

    Dhondt, S.; Ven, H. van de; Cressey, P.; Kaderabkova, A.; Luna, Á.; Moghadam Saman, S.; Castro Spila, J.; Terstriep, J.

    2016-01-01

    In this Policy Brief, a conceptual framework is presented to conduct an ex-ante impact assessment for social innovation. The building blocks for an ex-ante impact assessment are goal formulation; developing the relationships between inputs, outputs and outcomes; determining the role of stakeholders to achieve the objectives; calculating the impact; and deciding on the social innovation. These building blocks are sequentially interconnected to each other. In the brief, we present the experienc...

  11. 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.

  12. 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.

  13. 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.

  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. Behavioural and chemical evidence for multiple colonisation of the Argentine ant, Linepithema humile, in the Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Wossler Theresa C

    2011-02-01

    Full Text Available Abstract Background The Argentine ant, Linepithema humile, is a widespread invasive ant species that has successfully established in nearly all continents across the globe. Argentine ants are characterised by a social structure known as unicoloniality, where territorial boundaries between nests are absent and intraspecific aggression is rare. This is particularly pronounced in introduced populations and results in the formation of large and spatially expansive supercolonies. Although it is amongst the most well studied of invasive ants, very little work has been done on this ant in South Africa. In this first study, we investigate the population structure of Argentine ants in South Africa. We use behavioural (aggression tests and chemical (CHC approaches to investigate the population structure of Argentine ants within the Western Cape, identify the number of supercolonies and infer number of introductions. Results Both the aggression assays and chemical data revealed that the Western Cape Argentine ant population can be divided into two behaviourally and chemically distinct supercolonies. Intraspecific aggression was evident between the two supercolonies of Argentine ants with ants able to discriminate among conspecific non-nestmates. This discrimination is linked to the divergence in cuticular hydrocarbon profiles of ants originating from the two supercolonies. Conclusions The presence of these two distinct supercolonies is suggestive of at least two independent introductions of this ant within the Western Cape. Moreover, the pattern of colonisation observed in this study, with the two colonies interspersed, is in agreement with global patterns of Argentine ant invasions. Our findings are of interest because recent studies show that Argentine ants from South Africa are different from those identified in other introduced ranges and therefore provide an opportunity to further understand factors that determine the distributional and spread

  16. Isolation of a pyrazine alarm pheromone component from the fire ant, Solenopsis invicta.

    Science.gov (United States)

    Vander Meer, Robert K; Preston, Catherine A; Choi, Man-Yeon

    2010-02-01

    Alarm pheromones in social insects are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality. The alarm pheromones of ants were among the first examples of animal pheromones identified, primarily because of the large amount of chemical produced and the distinctive responses of ants to the pheromone. However, the alarm pheromone of the fire ant, Solenopsis invicta, eluded identification for over four decades. We identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of S. invicta. Worker fire ants detect the pyrazine alarm pheromone at 30 pg/ml, which is comparable to alarm pheromone sensitivities reported for other ant species. The source of this alarm pheromone are the mandibular glands, which, in fire ants, are not well developed and contain only about 300 pg of the compound, much less than the microgram quantities of alarm pheromones reported for several other ant species. Female and male sexuals and workers produce the pyrazine, which suggests that it may be involved in fire ant mating flight initiation, as well as the typical worker alarm response. This is the first report of 2-ethyl-3,6-dimethylpyrazine from a Solenopsis species and the first example of this alkaloid functioning as an alarm pheromone.

  17. 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.

  18. Bug City: Ants [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic…

  19. Movimiento social, proceso político y Mass media: el movimiento pacifista catalán ante los conflictos de Kosovo y Chechenia Movimiento social, proceso político y Mass media: el movimiento pacifista catalán ante los conflictos de Kosovo y Chechenia

    Directory of Open Access Journals (Sweden)

    Javier Alcalde Villacampa

    2004-01-01

    Full Text Available Can the level of protest be augmented considerably due to media coverage of a conflict? Though a theoretical framework based on the interaction between social movements, political process and the media, the paper compares the response of (he Catalan pacifist movement to two international conflicts: the war in Chechnya and the war in Kosovo. In the case of the Balkans, participation of the NATO will be a determinant, dividing the protest against that conflict into two different processes. In this study, the key independent variable is the media coverage that impacts on the political opportunity structure. Finally, I present hypothesis about the different strength of two Spanish social movements, that of Barcelona and in Madrid, related to the nationalistic question in Catalonia as a factor of politization.¿Puede incrementarse notablemente el nivel de protesta de un movimiento social a causa de la cobertura mediática de un conflicto? A partir de un marco teórico relativo a la interacción entre los movimientos sociales, el proceso político y los medios de comunicación el estudio analiza comparativamente la respuesta del movimiento pacifista catalán a dos conflictos internacionales: la guerra de Chechenia y la guerra de Kosovo. En el caso de los Balcanes, resulta determinante la participación de la OTAN, que subdivide el mismo en dos procesos distintos. En todos ellos, la principal variable independiente es la cobertura informativa realizada por la prensa escrita, la cual conforma uno de los factores que afectan a la estructura de oportunidad política. Los resultados sugieren que la existencia de movilización social solamente ocurrirá cuando participe la sociedad no organizada. jugando un papel esencial los medios de comunicación. Por último, esbozo algunas hipótesis a propósito de la distinta fuerza de los movimientos sociales en Madrid y en Barcelona, relacionadas con la cuestión nacional de Cataluña como factor de politización.

  20. Précis of The Ant Trap

    Directory of Open Access Journals (Sweden)

    Epstein Brian

    2016-03-01

    Full Text Available This article summarizes The Ant Trap: Rebuilding the Foundations of the Social Sciences. The book develops a new model for social ontology, applies it to groups and collective intentionality, and criticizes various forms of individualism. Part One of the book presents two traditional approaches to social ontology and unifies them into the “grounding–anchoring model” for the building of the social world. Part Two shows that individualism is mistaken even for basic facts about groups of people, challenges prevailing views of group intention and action, and illustrates how to approach facts about groups in general.

  1. 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

  2. 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

  3. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...... is known to include evolutionarily derived genera with obligate multiple mating (the Acromyrmex and Atta leafcutter ants) as well as phylogenetically basal genera with exclusively single mating (e.g. Apterostigma, Cyphomyrmex, Myrmicocrypta). All attine genera share the unique characteristic of obligate...... dependence on symbiotic fungus gardens for food, but the sophistication of this symbiosis differs considerably across genera. The lower attine genera generally have small, short-lived colonies and relatively non-specialized fungal symbionts (capable of living independently of their ant hosts), whereas...

  4. 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.

  5. Foraging of Psilocybe basidiocarps by the leaf-cutting ant Acromyrmex lobicornis in Santa Fé, Argentina.

    Science.gov (United States)

    Masiulionis, Virginia E; Weber, Roland Ws; Pagnocca, Fernando C

    2013-12-01

    It is generally accepted that material collected by leaf-cutting ants of the genus Acromyrmex consists solely of plant matter, which is used in the nest as substrate for a symbiotic fungus providing nutrition to the ants. There is only one previous report of any leaf-cutting ant foraging directly on fungal basidiocarps. Basidiocarps of Psilocybe coprophila growing on cow dung were actively collected by workers of Acromyrmex lobicornis in Santa Fé province, Argentina. During this behaviour the ants displayed typical signals of recognition and continuously recruited other foragers to the task. Basidiocarps of different stages of maturity were being transported into the nest by particular groups of workers, while other workers collected plant material. The collection of mature basidiocarps with viable spores by leaf-cutting ants in nature adds substance to theories relating to the origin of fungiculture in these highly specialized social insects.

  6. 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...

  7. Disease in the Society: Infectious Cadavers Result in Collapse of Ant Sub-Colonies

    Science.gov (United States)

    Loreto, Raquel G.; Hughes, David P.

    2016-01-01

    Despite the growing number of experimental studies on mechanisms of social immunity in ant societies, little is known about how social behavior relates to disease progression within the nests of ants. In fact, when empirically studying disease in ant societies, it is common to remove dead ants from experiments to confirm infection by the studied parasite. This unfortunately does not allow disease to progress within the nest as it may be assumed would happen under natural conditions. Therefore, the approach taken so far has resulted in a limited knowledge of diseases dynamics within the nest environment. Here we introduced a single infectious cadaver killed by the fungus Beauveria bassiana into small nests of the ant Camponotus castaneus. We then observed the natural progression of the disease by not removing the corpses of the ants that died following the first entry of the disease. Because some behaviors such as social isolation of sick individuals or the removal of cadavers by nestmates are considered social immune functions and thus adaptations at the colony level that reduce disease spread, we also experimentally confined some sub-colonies to one or two chamber nests to prevent the expression of such behaviors. Based on 51 small nests and survival studies in 1,003 ants we found that a single introduced infectious cadaver was able to transmit within the nest, and social immunity did not prevent the collapse of the small sub-colonies here tested. This was true whether ants did or did not have the option to remove the infectious cadaver. Therefore, we found no evidence that the typically studied social immunity behaviors can reduce disease spread in the conditions here tested. PMID:27529548

  8. 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.

  9. 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 ...

  10. 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....

  11. Ants: Major Functional Elements in Fruit Agro-Ecosystems and Biological Control Agents

    Directory of Open Access Journals (Sweden)

    Lamine Diamé

    2017-12-01

    Full Text Available Ants are a very diverse taxonomic group. They display remarkable social organization that has enabled them to be ubiquitous throughout the world. They make up approximately 10% of the world’s animal biomass. Ants provide ecosystem services in agrosystems by playing a major role in plant pollination, soil bioturbation, bioindication, and the regulation of crop-damaging insects. Over recent decades, there have been numerous studies in ant ecology and the focus on tree cropping systems has given added importance to ant ecology knowledge. The only missing point in this knowledge is the reasons underlying difference between the positive and negative effects of ants in tree cropping systems. This review article provides an overview of knowledge of the roles played by ants in orchards as functional elements, and on the potential of Oecophylla weaver ants as biological control agents. It also shows the potential and relevance of using ants as an agro-ecological diagnosis tool in orchards. Lastly, it demonstrates the potential elements which may determine the divergent negative and positive of their effects on cropping systems.

  12. 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....

  13. 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....

  14. Reduced entomopathogen abundance in Myrmica ant nests-testing a possible immunological benefit of myrmecophily using Galleria mellonella as a model

    DEFF Research Database (Denmark)

    Schär, Sämi; Larsen, Louise L.M.; Meyling, Nicolai Vitt

    2015-01-01

    Social insects such as ants have evolved collective rather than individual immune defence strategies against diseases and parasites at the level of their societies (colonies), known as social immunity. Ants frequently host other arthropods, so-called myrmecophiles, in their nests. Here, we tested...... that immunological benefits of entering ant nests may provide us a new explanation of why natural selection acts in favour of such a life-history strategy....

  15. 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.

  16. Patterns of host ant use by sympatric populations of Maculinea alcon and M. 'rebeli' in the Carpathian Basin

    DEFF Research Database (Denmark)

    Tartally, A.; Nash, David Richard; Lengyel, S.

    2008-01-01

    Maculinea butterflies show social parasitism via obligatory myrmecophily as their larvae are adopted and raised to pupation by Myrmica ants. Suitable hosts differ for different Maculinea species, and host ant specificity can further differ at the population-level. Although early studies suggested...... single ant species as main hosts for each Maculinea species, it has recently become clear that their host ant specificity is more complex. Maculinea alcon and Maculinea ‘rebeli’ have variously been separated according to adult and larval morphology, phenology, and their use of different ecosystems......, including host plant and host ant species. However, recent genetic evidence has questioned their separation as good species. Here we compare the use of host ants by M. alcon and M. ‘rebeli’ at the regional scale in NE-Hungary and Transylvania (Romania), where molecular studies have found no species...

  17. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (hymenoptera: formicidae)

    Science.gov (United States)

    Wang, Lei; Elliott, Brad; Jin, Xixuan; Zeng, Ling; Chen, Jian

    2015-12-01

    The antimicrobial property of volatiles produced by red imported fire ants, Solenopsis invicta, against Beauveria bassiana, a common entomopathogenic fungus, was demonstrated. The germination rate of B. bassiana spores was significantly reduced after they were exposed to volatiles within an artificial ant nest. Since the air that contained the same level of O2 and CO2 as that in artificial fire ant nests did not suppress the germination rate of B. bassiana, the observed reduction of germination rate must be caused by the toxicity of nest volatiles. Nest fumigation may be an important component of the social immune system in S. invicta.

  18. 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.

  19. Food collection and response to pheromones in an ant species exposed to electromagnetic radiation.

    Science.gov (United States)

    Cammaerts, Marie-Claire; Rachidi, Zoheir; Bellens, François; De Doncker, Philippe

    2013-09-01

    We used the ant species Myrmica sabuleti as a model to study the impact of electromagnetic waves on social insects' response to their pheromones and their food collection. We quantified M. sabuleti workers' response to their trail, area marking and alarm pheromone under normal conditions. Then, we quantified the same responses while under the influence of electromagnetic waves. Under such an influence, ants followed trails for only short distances, no longer arrived at marked areas and no longer orientated themselves to a source of alarm pheromone. Also when exposed to electromagnetic waves, ants became unable to return to their nest and recruit congeners; therefore, the number of ants collecting food increases only slightly and slowly. After 180 h of exposure, their colonies deteriorated. Electromagnetic radiation obviously affects social insects' behavior and physiology.

  20. António Reis and Margarida Cordeiro, eccentric filmmakers

    Directory of Open Access Journals (Sweden)

    Lucas Tavares Neves

    2016-02-01

    Full Text Available The international symposium "António Reis and Margarida Cordeiro, eccentric filmmakers" took place in Paris between the 3rd and the 4th of June, 2015. Speakers exchanged on the political, social and poetical aspects of the duo's cinematography, as well as on the reverberations of titles such as Jaime (1974 and Trás-os-montes (1976 on the Portuguese filmic landscape of the decades that followed.

  1. 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.

  2. 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.

  3. 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.

  4. Multiple Levels of Recognition in Ants: A Feature of Complex Societies

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia

    2008-01-01

    diverse. In ants, social interactions are regulated by at least three levels of recognition. Nestmate recognition occurs between colonies, is very effective, and involves fast processing. Within a colony, division of labor is enhanced by recognition of different classes of individuals. Ultimately......, in particular circumstances, such as cooperative colony founding with stable dominance hierarchies, ants are capable of individual recognition. The underlying recognition cues and mechanisms appear to be specific to each recognition level, and their integrated understanding could contribute...

  5. UM PASSARINHO NA MÃO OU DOIS VOANDO? DILEMAS DO GRUPO CARTEIRO AMIGO ENTRE SE EXPANDIR ORGANICAMENTE NA FAVELA DA ROCINHA OU SE ARRISCAR PARA ALÉM DA ZONA DE CONFORTO

    Directory of Open Access Journals (Sweden)

    Fernando Oliveira de Araujo

    Full Text Available RESUMO O presente estudo está situado na Rocinha, a maior favela da América Latina. Durante os primeiros anos da década de 2000, nessa tradicional comunidade carioca, além dos problemas de ordem social e econômica – como trafico de drogas, violência urbana e saneamento básico – seus moradores não eram assistidos com serviços públicos básicos como a entregade correspondências pelos Correios, tanto pela violência, quanto em virtude da ausência de padronização de endereços em suas ruas e vielas. Nesse contexto, três empreendedores observam uma oportunidade e deixam seus empregos para criarem o Grupo Carteiro Amigo (GCA, uma iniciativa que transformou a realidade da comunidade. O artigo apresenta um breve histórico da empresa e, em especial, aborda o dilema do crescimento organizacional, refletindo sobre os desafios e oportunidades de aumentar a base de clientes na Rocinha ou de franquear o negócio para outras favelas do Rio de Janeiro e do Brasil.

  6. Inclusión diferencial de extranjeros/migrantes a trasplantes de órganos: dilemas éticos frente a "prácticas no éticas"

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    Lourdes Basualdo

    Full Text Available Resumen Este artículo aborda el modo en que ciertos dilemas éticos vinculados al trasplante de órganos a extranjeros "no residentes", son movilizados por el Estado argentino en las normativas que definen un tratamiento diferenciado entre nacionales y no-nacionales en materia de trasplante, y cómo son puestos en relación con la política migratoria. Se muestra que existen mecanismos de inclusión diferencial que garantizan la inscripción a lista de espera sólo a nacionales y extranjeros "residentes" y permiten el trasplante con donante vivo a extranjeros "no residentes". Estos procesos de apertura y cierre de fronteras son posibles porque en el contexto actual coexisten la preocupación estatal en resguardar los bienes sociales proporcionados por el Estado (una de las funciones constitutivas del control migratorio y la obligación moral de los Estados-nación por el cuidado de la vida en el marco del gobierno humanitario.

  7. 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...

  8. 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

  9. Molecular structure and diversity of PBAN/Pyrokinin family peptides in ants

    Directory of Open Access Journals (Sweden)

    Man-Yeon eChoi

    2012-02-01

    Full Text Available Neuropeptides are the largest group of insect hormones. They are produced in the central and peripheral nervous systems and affect insect development, reproduction, feeding and behavior. A variety of neuropeptide families have been identified in insects. One of these families is the PBAN/pyrokinin family defined by a common FXPRLamide or similar amino acid fragment at the C-terminal end. These peptides, found in all insects studied thus far, have been conserved throughout evolution. The most well studied physiological function is regulation of moth sex pheromone biosynthesis through the Pheromone Biosynthesis Activating Neurohormone (PBAN, although several developmental functions have also been reported. Over the past years we have extended knowledge of the PBAN/pyrokinin family of peptides to ants, focusing mainly on the fire ant, Solenopsis invicta. The fire ant is one of the most studied social insects and over the last 60 years a great deal has been learned about many aspects of this ant, including the behaviors and chemistry of pheromone communication. However, virtually nothing is known about the regulation of these pheromone systems. Recently, we demonstrated the presence of PBAN/pyrokinin immunoreactive neurons in the fire ant, and identified and characterized PBAN and additional neuropeptides. We have mapped the fire ant PBAN gene structure and determined the tissue expression level in the central nervous system of the ant. We review here our research to date on the molecular structure and diversity of ant PBAN/pyrokinin peptides in preparation for determining the function of the neuropeptides in ants and other social insects.

  10. El juego como dispositivo de intervención ante la fragilidad actual de las instituciones sociales The game like intervention device in face of the current fragility of the social institutions

    Directory of Open Access Journals (Sweden)

    Graciela Paolicchi

    2009-12-01

    Full Text Available Este trabajo se inscribe en el marco de la investigación UBACyT, "La juegoteca como dispositivo de intervención en el lazo filiatorio: su impacto en la constitución de la función parental". Esta investigación obtiene sus insumos de un Programa de Extensión de la Facultad de Psicología de la Universidad de Buenos Aires focalizado en la creación de Juegotecas barriales. Se ha llevado a cabo en escuelas de contexto socioeconómico desfavorecido, consideradas en situación de elevada vulnerabilidad, del Distrito Escolar Nº 11 de la Ciudad Autónoma de Buenos Aires y en un comedor de San Telmo. Para ello se realizaron talleres con grupos de padres de niños que asisten a esas Instituciones, los que se orientan a propiciar un incremento en la capacidad de reflexión acerca del desarrollo infantil, en torno del eje que ubica al juego en lugar de relevancia en su impacto sobre la constitución subjetiva. Se presentan algunos resultados preliminares obtenidos en estos espacios.This work is inscribed in the framework of the investigation UBACyT, "The playground like intervention device in the family ties: their impact in the constitution of the relatives function ". This investigation obtains its input of a Program of Extension of the Ability of Psychology of the University of Buenos Aires focused in the creation of playgrounds. It has been carried out in the context of schools of disabled social economic context, considered in situation of high vulnerability, of the School District Nº 11 of the Autonomous City of Buenos Aires and in a dining room of San Telmo. For this reason they were carried out in workshops with parents of children groups that attended those educational Institutions, those that are guided to propitiate an increment in the reflection capacity about their infants' development, around the axis that locates the game in a place of relevance in its impact over the subjective constitution. Some preliminary results are presented

  11. Exploring agency beyond humans: the compatibility of Actor-Network Theory (ANT and resilience thinking

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    Angga Dwiartama

    2014-09-01

    Full Text Available At first glance, the compatibility of social theory and resilience thinking is not entirely evident, in part because the ontology of the former is rooted in social interactions among human beings rather than ecological process. Despite this difference, resilience thinking engages with particular aspects of social organization that have generated intense debates within social science, namely the role of humans as integral elements of social-ecological systems and the processes through which given social structures (including material relations are either maintained or transformed. Among social theoretical approaches, Actor-Network Theory (ANT is noted for its distinctive approach to these aspects. ANT proposes that human and nonhuman components (both referred to as actants have the same capacity to influence the development of social-ecological systems (represented as actor-networks by enacting relations and enrolling other actors. We explore the notion of agency that is employed in resilience thinking and ANT in order to extend our understandings of human-environment relationships through complementary insights from each approach. The discussion is illustrated by reference to ongoing assessment of resilience as it is experienced and expressed in two distinctive agricultural production systems: Indonesian rice and New Zealand kiwifruit. We conclude by establishing the potential for ANT to provide more profound theoretical conceptualizations of agency, both human and nonhuman, in analyses of social ecological systems.

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

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    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.

  13. 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...

  14. Does cooperation mean kinship between spatially discrete ant nests?

    Science.gov (United States)

    Procter, Duncan S; Cottrell, Joan E; Watts, Kevin; A'Hara, Stuart W; Hofreiter, Michael; Robinson, Elva J H

    2016-12-01

    Eusociality is one of the most complex forms of social organization, characterized by cooperative and reproductive units termed colonies. Altruistic behavior of workers within colonies is explained by inclusive fitness, with indirect fitness benefits accrued by helping kin. Members of a social insect colony are expected to be more closely related to one another than they are to other conspecifics. In many social insects, the colony can extend to multiple socially connected but spatially separate nests (polydomy). Social connections, such as trails between nests, promote cooperation and resource exchange, and we predict that workers from socially connected nests will have higher internest relatedness than those from socially unconnected, and noncooperating, nests. We measure social connections, resource exchange, and internest genetic relatedness in the polydomous wood ant Formica lugubris to test whether (1) socially connected but spatially separate nests cooperate, and (2) high internest relatedness is the underlying driver of this cooperation. Our results show that socially connected nests exhibit movement of workers and resources, which suggests they do cooperate, whereas unconnected nests do not. However, we find no difference in internest genetic relatedness between socially connected and unconnected nest pairs, both show high kinship. Our results suggest that neighboring pairs of connected nests show a social and cooperative distinction, but no genetic distinction. We hypothesize that the loss of a social connection may initiate ecological divergence within colonies. Genetic divergence between neighboring nests may build up only later, as a consequence rather than a cause of colony separation.

  15. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    Science.gov (United States)

    In social insects, antimicrobial secretions are often used collectively for the benefit of the whole colony, which is an important component in social immunity. Many ant species build nests in which air circulation can be controlled. Volatile antimicrobial agents would be ideal in implementing socia...

  16. 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...

  17. 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.

  18. 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.

  19. The Evolutionary Ecology of Multi-Queen Breeding in Ants

    DEFF Research Database (Denmark)

    Huszár, Dóra Borbála

    on other ant species to better understand the social syndromes and how supercolonies function. Foremost, this would help to manage invasive supercolonies that harm humans and biodiversity, but could also provide contribution to our general understanding on how ecology, especially demography impacts upon......). Multi-queen breeding requires both social and life-history adaptations from individuals to decrease intra-colony conflicts and to ensure that sterile workers receive inclusive fitness benefits despite lowered relatedness. However, it remains unclear exactly what ecological and life-history covariates...

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. Nest etiquette--where ants go when nature calls.

    Directory of Open Access Journals (Sweden)

    Tomer J Czaczkes

    Full Text Available Sanitary behaviour is an important, but seldom studied, aspect of social living. Social insects have developed several strategies for dealing with waste and faecal matter, including dumping waste outside the nest and forming specialised waste-storage chambers. In some cases waste material and faeces are put to use, either as a construction material or as a long-lasting signal, suggesting that faeces and waste may not always be dangerous. Here we examine a previously undescribed behaviour in ants - the formation of well-defined faecal patches. Lasius niger ants were housed in plaster nests and provided with coloured sucrose solution. After two months, 1-4 well defined dark patches, the colour of the sucrose solution, formed within each of the plaster nests. These patches never contained other waste material such as uneaten food items, or nestmate corpses. Such waste was collected in waste piles outside the nest. The coloured patches were thus distinct from previously described 'kitchen middens' in ants, and are best described as 'toilets'. Why faeces is not removed with other waste materials is unclear. The presence of the toilets inside the nest suggests that they may not be an important source of pathogens, and may have a beneficial role.

  5. Ant brood function as life preservers during floods.

    Directory of Open Access Journals (Sweden)

    Jessica Purcell

    Full Text Available Social organisms can surmount many ecological challenges by working collectively. An impressive example of such collective behavior occurs when ants physically link together into floating 'rafts' to escape from flooded habitat. However, raft formation may represent a social dilemma, with some positions posing greater individual risks than others. Here, we investigate the position and function of different colony members, and the costs and benefits of this functional geometry in rafts of the floodplain-dwelling ant Formica selysi. By causing groups of ants to raft in the laboratory, we observe that workers are distributed throughout the raft, queens are always in the center, and 100% of brood items are placed on the base. Through a series of experiments, we show that workers and brood are extremely resistant to submersion. Both workers and brood exhibit high survival rates after they have rafted, suggesting that occupying the base of the raft is not as costly as expected. The placement of all brood on the base of one cohesive raft confers several benefits: it preserves colony integrity, takes advantage of brood buoyancy, and increases the proportion of workers that immediately recover after rafting.

  6. Chemical and behavioral integration of army ant-associated rove beetles - a comparison between specialists and generalists.

    Science.gov (United States)

    von Beeren, Christoph; Brückner, Adrian; Maruyama, Munetoshi; Burke, Griffin; Wieschollek, Jana; Kronauer, Daniel J C

    2018-01-01

    Host-symbiont interactions are embedded in ecological communities and range from unspecific to highly specific relationships. Army ants and their arthropod guests represent a fascinating example of species-rich host-symbiont associations where host specificity ranges across the entire generalist - specialist continuum. In the present study, we compared the behavioral and chemical integration mechanisms of two extremes of the generalist - specialist continuum: generalist ant-predators in the genus Tetradonia (Staphylinidae: Aleocharinae: Athetini), and specialist ant-mimics in the genera Ecitomorpha and Ecitophya (Staphylinidae: Aleocharinae: Ecitocharini). Similar to a previous study of Tetradonia beetles, we combined DNA barcoding with morphological studies to define species boundaries in ant-mimicking beetles. This approach found four ant-mimicking species at our study site at La Selva Biological Station in Costa Rica. Community sampling of Eciton army ant parasites revealed that ant-mimicking beetles were perfect host specialists, each beetle species being associated with a single Eciton species. These specialists were seamlessly integrated into the host colony, while generalists avoided physical contact to host ants in behavioral assays. Analysis of the ants' nestmate recognition cues, i.e. cuticular hydrocarbons (CHCs), showed close similarity in CHC composition and CHC concentration between specialists and Eciton burchellii foreli host ants. On the contrary, the chemical profiles of generalists matched host profiles less well, indicating that high accuracy in chemical host resemblance is only accomplished by socially integrated species. Considering the interplay between behavior, morphology, and cuticular chemistry, specialists but not generalists have cracked the ants' social code with respect to various sensory modalities. Our results support the long-standing idea that the evolution of host-specialization in parasites is a trade-off between the range of

  7. 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...

  8. 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.

  9. 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.

  10. Actitudes europeos ante el envejecimiento y los personas mayores

    Directory of Open Access Journals (Sweden)

    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.

  11. Autonomous Agents on Expedition: Humans and Progenitor Ants and Planetary Exploration

    Science.gov (United States)

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

    2002-01-01

    The Autonomous Nano-Technology Swarm (ANTS) is an advanced mission architecture based on a social insect analog of many specialized spacecraft working together to achieve mission goals. The principal mission concept driving the ANTS architecture is a Main Belt Asteroid Survey in the 2020s that will involve a thousand or more nano-technology enabled, artificially intelligent, autonomous pico-spacecraft (architecture. High level, mission-oriented behaviors are to be managed by a control / communications layer of the swarm, whereas common low level functions required of all spacecraft, e.g. attitude control and guidance and navigation, are handled autonomically on each spacecraft. At the higher levels of mission planning and social interaction deliberative techniques are to be used. For the asteroid survey, ANTS acts as a large community of cooperative agents while for precursor missions there arises the intriguing possibility of Progenitor ANTS and humans acting together as agents. For optimal efficiency and responsiveness for individual spacecraft at the lowest levels of control we have been studying control methods based on nonlinear dynamical systems. We describe the critically important autonomous control architecture of the ANTS mission concept and a sequence of partial implementations that feature increasingly autonomous behaviors. The scientific and engineering roles that these Progenitor ANTS could play in human missions or remote missions with near real time human interactions, particularly to the Moon and Mars, will be discussed.

  12. Olfactory memory established during trophallaxis affects food search behaviour in ants.

    Science.gov (United States)

    Provecho, Yael; Josens, Roxana

    2009-10-01

    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, as a nectar source. After a single trophallaxis of a scented solution, the receiver ant was tested in a Y-maze without any reward, where two scents were presented: in one arm, the solution scent and in the other, a new scent. Ants consistently chose the arm with the solution scent and stayed longer therein. Trophallaxis duration had no effect on the arm choice or with the time spent in each arm. Workers are able to associate an odour (conditioned stimulus) with the sucrose (unconditioned stimulus) they receive through a social interaction and use this memory as choice criteria during food searching.

  13. Evolutionary transition from single to multiple mating in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Frydenberg, Jane

    1999-01-01

    Queens of leafcutter ants exhibit the highest known levels of multiple mating (up to 10 mates per queen) among ants. Multiple mating may have been selected to increase genetic diversity among nestmate workers, which is hypothesized to be critical in social systems with large, long-lived colonies...... under severe pressure of pathogens. Advanced fungus-growing (leafcutter) ants have large numbers (104-106 workers) and long-lived colonies, whereas basal genera in the attine tribe have small (... to have lower queen mating frequencies, similar to those found in most other ants. We tested this prediction by analysing queen mating frequency and colony kin structure in three basal attine species: Myrmicocrypta ednaella, Apterostigma collare and Cyphomyrmex longiscapus. Microsatellite marker analyses...

  14. 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.

  15. 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.

  16. 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.

  17. ANTS/PAM: Future Exploration of the Asteroid Belt

    Science.gov (United States)

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

    2004-05-01

    The Autonomous Nano-Technology Swarm (ANTS) is applied to the Prospecting Asteroid Mission (PAM) concept, as part of a NASA RASC study. The ANTS architecture is inspired by success of social insect colonies, based on the division of labor within the colonies: 1) within their specialties, individual specialists generally outperform general-ists, and 2) with sufficiently efficient social interaction and coordination, the group of specialists generally outper-forms the group of generalists. ANTS as applied to PAM involves a thousand individual specialist `sciencecraft', one subswarm per target, in an environment where detection and tracking of irregular, infrequent targets is a major chal-lenge. Workers, carry and operate eight to nine different scientific instruments, including spectrometers, ranging and radio science devices, imagers. The remaining specialists, Messenger/Rulers, provide communication and coordina-tion. The non-expendable propulsion system is based on autonomously deployable and configurable solar sails, a system suitable to a low gravity environment. The design of the neural basis function requires a minimum of 4 or 5 specialists for collective decision making. Allowing for ten instrument specialist teams and compensating for antici-pated high attrition, we calculate an initial minimum of 100 per subswarm should allow characterization of hundreds of asteroids. The difficulty in observing irregular, rapidly moving, poorly illuminated objects is largely overcome by the ANT sciencecraft capability to optimize conditions for each instrument. Components are composed of carbon nanotubules reversibly deployable from NEMS nodes, allowing 100 times decrease in packaging volume. 1000 smart 10 centimeter, 1 kg cubic boxes create a 1000 kg 1 meter cube.

  18. 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.

  19. 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 ...

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Dilemas da agenda social na América Latina e efeitos das eleições presidenciais recentes

    Directory of Open Access Journals (Sweden)

    Ana Maria Fernandes

    2007-12-01

    Full Text Available Ao final dos anos oitenta, com Margareth Thatcher e Ronald Reagan, o Reino Unido e os Estados Unidos assumiram a liderança de uma verdadeira revolução capitalista, com menores impostos aos ricos, menor taxação dos lucros, privatizações em massa e a tentativa de consolidar as bolsas de valores como sendo prioritárias fontes de crédito frente à dependência do setor bancário.

  9. PRINCIPALES DILEMAS BIOÉTICOS EN LAS PERSONAS CON DISCAPACIDAD PROLONGADA PRINCIPAIS DILEMMAS BIOÉTICOS NOS POVOS COM DISCAPACIDADE PROLONGADA MOST IMPORTANT BIOETHICAL DILEMMAS OF PEOPLE WITH LONG TERM DISABILITIES

    Directory of Open Access Journals (Sweden)

    Laura Rueda Castro

    2002-01-01

    Full Text Available Reconocida es a nivel mundial la dificultad para alcanzar la plena participación e integración social de las personas con discapacidad, situación que involucra valores éticos fundamentales. Un aporte importante será la apli-cación de principios bioéticos orientadores del quehacer profesional bajo un nuevo paradigma. Dilemas bioéticos como el consentimiento informado y la participación de la persona en la toma de decisiones que afectan su propia vida, implican para el profesional un desafío, la entrega de información adecuada y oportuna, el desarrollo de conductas profesionales que favorezcan la autonomía y el reconocimiento de estas personas como interlocutores válidos. Del mismo modo ocurre cuando abordamos la sexualidad de las personas con discapacidad. Los profesionales deben permitir el desarrollo integral de las personas, reconociendo la sexualidad como un aspecto fundamental del ser humano, y frente al cual tienen derecho a ser orientados y educados tomando como base su historia biográfica y lo que cada uno desea de la vida (autodeterminación. Deben ser considerados por tanto, principios bioéticos funda-mentales como la Justicia y la AutonomíaÉ reconhecida em nível mundial as dificuldades que se impõem às pessoas portadoras de incapacidades para plena participação e integração social, o que envolve valores éticos fundamentais. Contribuição importante será obtida através de aplicação de princípios bioéticos que orientem a atividade profissional sob novo paradigma. Dilemas como o consentimento informado e a participação de pessoas na tomada de decisões que afetam sua própria vida implicam em desafio para o profissional. De igual modo, o oferecimento da informação adequada e oportuna, o desenvolvimento de condutas profissionais que favoreçam a autonomia e o reconhecimento dessas pessoas como interlocutores válidos. O mesmo ocorre quando tratamos da sexualidade de pessoas portadoras de incapacidades

  10. An ant colony based resilience approach to cascading failures in cluster supply network

    Science.gov (United States)

    Wang, Yingcong; Xiao, Renbin

    2016-11-01

    Cluster supply chain network is a typical complex network and easily suffers cascading failures under disruption events, which is caused by the under-load of enterprises. Improving network resilience can increase the ability of recovery from cascading failures. Social resilience is found in ant colony and comes from ant's spatial fidelity zones (SFZ). Starting from the under-load failures, this paper proposes a resilience method to cascading failures in cluster supply chain network by leveraging on social resilience of ant colony. First, the mapping between ant colony SFZ and cluster supply chain network SFZ is presented. Second, a new cascading model for cluster supply chain network is constructed based on under-load failures. Then, the SFZ-based resilience method and index to cascading failures are developed according to ant colony's social resilience. Finally, a numerical simulation and a case study are used to verify the validity of the cascading model and the resilience method. Experimental results show that, the cluster supply chain network becomes resilient to cascading failures under the SFZ-based resilience method, and the cluster supply chain network resilience can be enhanced by improving the ability of enterprises to recover and adjust.

  11. 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...

  12. 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 ...

  13. Foraging strategies of the ant Ectatomma vizottoi (Hymenoptera, Formicidae

    Directory of Open Access Journals (Sweden)

    Luan D. Lima

    2013-12-01

    Full Text Available Foraging strategies of the ant Ectatomma vizottoi (Hymenoptera, Formicidae. Foraging activity may be limited by temperature, humidity, radiation, wind, and other abiotic factors, all of which can affect energy costs during foraging. Ectatomma vizottoi's biology has only recently been studied, and no detailed information is available on its foraging patterns or diet in the field. For this reason, and because foraging activity is an important part of the ecological success of social insects, the present study aimed to investigate E. vizottoi's foraging strategies and dietary habits. First, we determined how abiotic factors constrained E. vizottoi's foraging patterns in the field by monitoring the foraging activity of 16 colonies on eight different days across two seasons. Second, we characterized E. vizottoi's diet by monitoring another set of 26 colonies during peak foraging activity. Our results show that E. vizottoi has foraging strategies that are similar to those of congeneric species. In spite of having a low efficiency index, colonies adopted strategies that allowed them to successfully obtain food resources while avoiding adverse conditions. These strategies included preying on other ant species, a foraging tactic that could arise if a wide variety of food items are not available in the environment or if E. vizottoi simply prefers, regardless of resource availability, to prey on other invertebrates and especially on other ant species.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. investigando el dilema urbano: urbanización, pobreza y violencia

    International Development Research Centre (IDRC) Digital Library (Canada)

    interés en los asuntos relativos a la urbanización, la pobreza y la violencia urbanas entre los científicos sociales. ..... explicativo son puestos a prueba por tendencias como el surgimiento de las ..... A pesar de que las pandillas han existido en todo el mundo por .... de programas e iniciativas demuestra que ciertas formas.

  19. Cloning and sequencing of wsp encoding gene fragments reveals a diversity of co-infecting Wolbachia strains in Acromyrmex leafcutter ants

    DEFF Research Database (Denmark)

    van Borm, S.; Wenseleers, T.; Billen, J.

    2003-01-01

    Acromyrmex insinuator hosted two additional infections. The multiple Wolbachia strains may influence the expression of reproductive conflicts in leafcutter ants, but the expected turnover of infections may make the cumulative effects on host ant reproduction complex. The additional Wolbachia infections......By sequencing part of the wsp gene of a series of clones, we detected an unusually high diversity of nine Wolbachia strains in queens of three species of leafcutter ants. Up to four strains co-occurred in a single ant. Most strains occurred in two clusters (InvA and InvB), but the social parasite...

  20. The mandible opening response: quantifying aggression elicited by chemical cues in ants

    DEFF Research Database (Denmark)

    Guerrieri, Fernando J; d'Ettorre, Patrizia

    2008-01-01

    Social insects have evolved efficient recognition systems guaranteeing social cohesion and protection from enemies. To defend their territories and threaten non-nestmate intruders, ants open their mandibles as a first aggressive display. Albeit chemical cues play a major role in discrimination...... genus have more similar profiles. The antennae of harnessed ants were touched with a glass rod coated with the cuticular extract of (a) nestmates, (b) non-nestmates of the same species, (c) another species of the same genus and (d) a species of a different genus. The mandible opening response (MOR......) was recorded as the aggressive response. In all assayed species, MOR significantly differed among stimuli, being weakest towards nestmate odour and strongest towards odours originating from ants of a different genus. We thus introduce here a new procedure suitable for studying the chemical basis of aggression...

  1. Destructive disinfection of infected brood prevents systemic disease spread in ant colonies.

    Science.gov (United States)

    Pull, Christopher D; Ugelvig, Line V; Wiesenhofer, Florian; Grasse, Anna V; Tragust, Simon; Schmitt, Thomas; Brown, Mark Jf; Cremer, Sylvia

    2018-01-09

    In social groups, infections have the potential to spread rapidly and cause disease outbreaks. Here, we show that in a social insect, the ant Lasius neglectus , the negative consequences of fungal infections ( Metarhizium brunneum ) can be mitigated by employing an efficient multicomponent behaviour, termed destructive disinfection, which prevents further spread of the disease through the colony. Ants specifically target infected pupae during the pathogen's non-contagious incubation period, utilising chemical 'sickness cues' emitted by pupae. They then remove the pupal cocoon, perforate its cuticle and administer antimicrobial poison, which enters the body and prevents pathogen replication from the inside out. Like the immune system of a metazoan body that specifically targets and eliminates infected cells, ants destroy infected brood to stop the pathogen completing its lifecycle, thus protecting the rest of the colony. Hence, in an analogous fashion, the same principles of disease defence apply at different levels of biological organisation.

  2. Genetic royal cheats in leaf-cutting ant societies

    DEFF Research Database (Denmark)

    Hughes, William O H; Boomsma, Jacobus J

    2008-01-01

    of the former. The most significant potential conflict in social insect colonies is over which individuals become reproductive queens rather than sterile workers. This reproductive division of labor is a defining characteristic of eusocial societies, but individual larvae will maximize their fitness by becoming...... queens whereas their nestmates will generally maximize fitness by forcing larvae to become workers. However, evolutionary constraints are thought to prevent cheating by removing genetic variation in caste propensity. Here, we show that one-fifth of leaf-cutting ant patrilines cheat their nestmates...

  3. Estilos de afrontamiento ante eventos estresantes en la infancia

    OpenAIRE

    Hernández Altamirano,Sheila Viridiana; Gutiérrez Lara,Mariana

    2012-01-01

    El afrontamiento es una variable mediadora de la adaptación y de los eventos estresantes de la vida diaria de un individuo. En el caso del infante le permite lidiar con los cambios físicos, psicológicos, familiares, sociales y académicos típicos de su edad. El objetivo de esta investigación fue identificar los estilos de afrontamiento utilizados por niños de 10 a 13 años de edad ante eventos estresantes. Para ello se realizó un estudio descriptivo en el cual los estilos de afrontamiento fuero...

  4. Do host species evolve a specific response to slave-making ants?

    Directory of Open Access Journals (Sweden)

    Delattre Olivier

    2012-12-01

    Full Text Available Abstract Background Social parasitism is an important selective pressure for social insect species. It is particularly the case for the hosts of dulotic (so called slave-making ants, which pillage the brood of host colonies to increase the worker force of their own colony. Such raids can have an important impact on the fitness of the host nest. An arms race which can lead to geographic variation in host defenses is thus expected between hosts and parasites. In this study we tested whether the presence of a social parasite (the dulotic ant Myrmoxenus ravouxi within an ant community correlated with a specific behavioral defense strategy of local host or non-host populations of Temnothorax ants. Social recognition often leads to more or less pronounced agonistic interactions between non-nestmates ants. Here, we monitored agonistic behaviors to assess whether ants discriminate social parasites from other ants. It is now well-known that ants essentially rely on cuticular hydrocarbons to discriminate nestmates from aliens. If host species have evolved a specific recognition mechanism for their parasite, we hypothesize that the differences in behavioral responses would not be fully explained simply by quantitative dissimilarity in cuticular hydrocarbon profiles, but should also involve a qualitative response due to the detection of particular compounds. We scaled the behavioral results according to the quantitative chemical distance between host and parasite colonies to test this hypothesis. Results Cuticular hydrocarbon profiles were distinct between species, but host species did not show a clearly higher aggression rate towards the parasite than toward non-parasite intruders, unless the degree of response was scaled by the chemical distance between intruders and recipient colonies. By doing so, we show that workers of the host and of a non-host species in the parasitized site displayed more agonistic behaviors (bites and ejections towards parasite

  5. 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 ...

  6. 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...

  7. 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

  8. 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....

  9. Myrmica Ants and Their Butterfly Parasites with Special Focus on the Acoustic Communication

    Directory of Open Access Journals (Sweden)

    F. Barbero

    2012-01-01

    Full Text Available About 10,000 arthropod species live as ants' social parasites and have evolved a number of mechanisms allowing them to penetrate and survive inside the ant nests. Myrmica colonies, in particular, are exploited by numerous social parasites, and the presence of their overwintering brood, as well as of their polygyny, contributes to make them more vulnerable to infestation. Butterflies of the genus Maculinea are among the most investigated Myrmica inquilines. These lycaenids are known for their very complex biological cycles. Maculinea species are obligated parasites that depend on a particular food plant and on a specific Myrmica species for their survival. Maculinea larvae are adopted by Myrmica ants, which are induced to take them into their nests by chemical mimicry. Then the parasite spends the following 11–23 months inside the ants' nest. Mimicking the acoustic emission of the queen ants, Maculinea parasites not only manage to become integrated, but attain highest rank within the colony. Here we review the biology of Maculinea/Myrmica system with a special focus on some recent breakthrough concerning their acoustical patterns.

  10. 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. ...

  11. 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

  12. 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...

  13. 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.

  14. 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.

  15. Entre el trabajo y el cuerpo: motivos, estrategias y dilemas de los profesionales por cuenta propia

    OpenAIRE

    Gorroño Arregui, Idoya

    2016-01-01

    La Tesis parte de la hipótesis de que las mujeres profesionales que deciden emprender por cuenta propia tras una etapa como asalariadas, a diferencia de los hombres, representan símbolos de cambio a la hora de emprender un proyecto profesional propio más coherente con sus valores y de relacionarse con los demás y crear redes (Ibarra, 2004). Esto supondría la emergencia de un cambio cultural y social más profundo en el mundo laboral (Castells, 2012) bajo el paradigma del trabajo flexible y por...

  16. A review of myrmecophily in ant nest beetles (Coleoptera: Carabidae: Paussinae): linking early observations with recent findings

    Science.gov (United States)

    Geiselhardt, Stefanie F.; Peschke, Klaus; Nagel, Peter

    2007-11-01

    Myrmecophily provides various examples of how social structures can be overcome to exploit vast and well-protected resources. Ant nest beetles (Paussinae) are particularly well suited for ecological and evolutionary considerations in the context of association with ants because life habits within the subfamily range from free-living and predatory in basal taxa to obligatory myrmecophily in derived Paussini. Adult Paussini are accepted in the ant society, although parasitising the colony by preying on ant brood. Host species mainly belong to the ant families Myrmicinae and Formicinae, but at least several paussine genera are not host-specific. Morphological adaptations, such as special glands and associated tufts of hair (trichomes), characterise Paussini as typical myrmecophiles and lead to two different strategical types of body shape: while certain Paussini rely on the protective type with less exposed extremities, other genera access ant colonies using glandular secretions and trichomes (symphile type). We compare these adaptations with other taxonomic groups of insects by joining contemporary research and early sources and discuss the possibility of an attracting or appeasing effect of the secretion. Species that are ignored by their host ants might use chemical mimicry instead. Furthermore, vibrational signals may contribute to ant-beetle communication, and chemical signals have proven to play a role in host finding. The powerful defense chemistry of paussines as “bombardier beetles” is not used in contact with host ants. We attempt to trace the evolution of myrmecophily in paussines by reviewing important aspects of the association between paussine beetles and ants, i.e. morphological and potential chemical adaptations, life cycle, host specificity, alimentation, parasitism and sound production.

  17. 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

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    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

  18. Kinins in ant venoms--a comparison with venoms of related Hymenoptera

    NARCIS (Netherlands)

    Piek, T.; Schmidt, J. O.; de Jong, J. M.; Mantel, P.

    1989-01-01

    1. Venom preparations have been made of six ant, one pompilid wasp, two mutillid wasp, and four social wasp species. 2. The venoms were analysed pharmacologically in order to detect kinin-like activity. 3. Due to the small amounts of venoms available only a cascade of smooth muscle preparation could

  19. Digest: Ant workers might use ancient regulatory pathways to divide labor

    Czech Academy of Sciences Publication Activity Database

    Ernst, Ulrich R.

    2017-01-01

    Roč. 71, č. 1 (2017), s. 193-194 ISSN 0014-3820 Institutional support: RVO:61388963 Keywords : regulatory pathways * social insect * ants Subject RIV: EH - Ecology, Behaviour OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 4.201, year: 2016

  20. Private information alone can trigger trapping of ant colonies in local feeding optima.

    Science.gov (United States)

    Czaczkes, Tomer J; Salmane, Anete K; Klampfleuthner, Felicia A M; Heinze, Jürgen

    2016-03-01

    Ant colonies are famous for using trail pheromones to make collective decisions. Trail pheromone systems are characterised by positive feedback, which results in rapid collective decision making. However, in an iconic experiment, ants were shown to become 'trapped' in exploiting a poor food source, if it was discovered earlier. This has conventionally been explained by the established pheromone trail becoming too strong for new trails to compete. However, many social insects have a well-developed memory, and private information often overrules conflicting social information. Thus, route memory could also explain this collective 'trapping' effect. Here, we disentangled the effects of social and private information in two 'trapping' experiments: one in which ants were presented with a good and a poor food source, and one in which ants were presented with a long and a short path to the same food source. We found that private information is sufficient to trigger trapping in selecting the poorer of two food sources, and may be sufficient to cause it altogether. Memories did not trigger trapping in the shortest path experiment, probably because sufficiently detailed memories did not form. The fact that collective decisions can be triggered by private information alone may require other collective patterns previously attributed solely to social information use to be reconsidered. © 2016. Published by The Company of Biologists Ltd.

  1. dilemas de una nación pluricultural en la perspectiva del centenario

    OpenAIRE

    Guzmán Chávez, Mauricio Genet

    2010-01-01

    En este artículo ofrecemos una reflexión sobre los contenidos ideológicos que fundan en el Estado mexicano a partir de la Revolución de 1910. No se pretende un examen cronológico de eventos, sino una revisión crítica de los fundamentos que posibilitaron la construcción nacional a partir de un pacto social que hoy en día no rige más a la sociedad mexicana. De esta forma hurgamos en las tensiones políticas identificativas para llevar adelante un proyecto de homogeneización cultural, en un país ...

  2. Observations of the "egg white injury" in ants.

    Directory of Open Access Journals (Sweden)

    Laure-Anne Poissonnier

    Full Text Available A key determinant of the relationship between diet and longevity is the balance of protein to carbohydrate in the diet. Eating excess protein relative to carbohydrate shortens lifespan in solitary and social insects. Here we explored how lifespan and behavior in ants was affected by the quality of protein ingested and the presence of associated antinutrients (i.e. compounds that interfere with the absorption of nutrients. We tested diets prepared with either egg white protein only or a protein mixture. Egg white contains an anti-nutrient called avidin. Avidin binds to the B vitamin biotin, preventing its absorption. First, we demonstrate that an egg-white diet was twice as deleterious as a protein-mixture diet. Second, we show that ingestion of egg-white diet drastically affected social behavior, triggering elevated levels of aggression within the colony. Lastly, we reveal that by adding biotin to the egg white diet we were able to lessen its detrimental effects. This latest result suggests that ants suffered biotin deficiency when fed the egg white diet. In conclusion, anti-nutrients were known to affect health and performance of animals, but this is the first study showing that anti-nutrients also lead to severe changes in behavior.

  3. Sex ratio and Wolbachia infection in the ant Formica exsecta.

    Science.gov (United States)

    Keller, L; Liautard, C; Reuter, M; Brown, W D; Sundström, L; Chapuisat, M

    2001-08-01

    Sex allocation data in social Hymenoptera provide some of the best tests of kin selection, parent-offspring conflict and sex ratio theories. However, these studies critically depend on controlling for confounding ecological factors and on identifying all parties that potentially manipulate colony sex ratio. It has been suggested that maternally inherited parasites may influence sex allocation in social Hymenoptera. If the parasites can influence sex allocation, infected colonies are predicted to invest more resources in females than non-infected colonies, because the parasites are transmitted through females but not males. Prime candidates for such sex ratio manipulation are Wolbachia, because these cytoplasmically transmitted bacteria have been shown to affect the sex ratio of host arthropods by cytoplasmic incompatibility, parthenogenesis, male-killing and feminization. In this study, we tested whether Wolbachia infection is associated with colony sex ratio in two populations of the ant Formica exsecta that have been the subject of extensive sex ratio studies. In these populations colonies specialize in the production of one sex or the other. We found that almost all F. exsecta colonies in both populations are infected with Wolbachia. However, in neither population did we find a significant association in the predicted direction between the prevalence of Wolbachia and colony sex ratio. In particular, colonies with a higher proportion of infected workers did not produce more females. Hence, we conclude that Wolbachia does not seem to alter the sex ratio of its hosts as a means to increase transmission rate in these two populations of ants.

  4. 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.

  5. DISPONIBILIDAD Y ACCESIBILIDAD EN EL TRANSPORTE PÚBLICO MADRILEÑO COMO GARANTÍA DE EQUIDAD SOCIAL ANTE LA APLICACIÓN DE UN PEAJE URBANO PARA LA CIUDAD DE MADRID

    Directory of Open Access Journals (Sweden)

    Muñoz Miguel, Juan Pedro

    2014-01-01

    Full Text Available Un transporte público urbano suficientemente accesible constituye uno de los principales condicionantes para la implantación de peajes urbanos, lo que permite garantizar, además de un adecuado nivel de equidad social en la movilidad, un elevado grado de aceptación social. El presente artículo sobre la basede una encuesta poblacional para la ciudad de Madrid y su entorno ofrece una valoración sobre la actual accesibilidad que presenta el transporte madrileño como garantía de equidad social en la movilidad bajo una situación de peaje urbano, donde los resultados muestran que el sistema permitiría garantizar un nivel de equidad en la movilidad muy significativo y relevante para los desplazamientos interiores y radiales respectivamente, con alcance muy reducido para los desplazamientos transversales, si bien el empleo de determinadas estrategias puede constituir un factor crucial que favorezca la equidad social deseable para el peaje urbano.

  6. Hacia una economía sostenible : dilemas del ecologismo actual

    Directory of Open Access Journals (Sweden)

    Joan Martínez Alier

    2013-10-01

    Full Text Available Este texto fue leído en Barcelona el 14 de diciembre del 2010 al capítulo catalán del Club de Roma. Analiza las tendencias demográficas, la creciente producción de dióxido de carbono y la pérdida de biodiversidad en el mundo. Critica el optimismo tecnológico que lleva a creer en el crecimiento económico y por lo tanto conduce a infravalorar las necesidades ambientales de nuestros descendientes. Explica que la economía tiene tres pisos. En la economía actual el sector financiero se despega peligrosamente del sector productivo y éste mismo depende, realmente, no tanto de los procesos económicos como de la disponibilidad de recursos naturales y de la existencia de sumideros para los residuos. El creciente metabolismo social (uso cada vez mayor de energía y materiales produce muchos conflictos ecológicos cuyos protagonistas son poblaciones campesinas e indígenas. Este "ecologismo de los pobres", esas luchas por la justicia ambiental, pueden dirigir la economía hacia una senda más sostenible. El texto une así el análisis de la economía ecológica con el análisis de la ecología política.

  7. Saberes e interculturalidad: Dilemas y aprendizajes en una experiencia con afrodescendientes colombianas

    Directory of Open Access Journals (Sweden)

    María Irene Victoria-Morales

    2017-01-01

    Full Text Available Este artículo describe los resultados de la investigación: Diálogos afrocéntricos y occidentales en el entrenamiento de terapeutas comunitarios, que se desarrolló en 2013 con una metodología de acción participativa. El propósito del estudio fue analizar cómo un grupo de mujeres colombianas afrodescendientes, desplazadas de la Costa Pacífica en la ciudad de Cali, construyeron sentido en un encuentro pedagógico con un grupo de estudiantes estadounidenses del programa de terapia familiar de la universidad Lewis & Clark, en Portland, Oregon. Los resultados examinan los siguientes temas: el proceso de las mujeres de construcción colectiva de sentido sobre sus saberes como prácticas de resistencia; el significado crítico, nuevo y emergente de las prácticas culturales como una posibilidad de reconfigurar la identidad colectiva; la reconstrucción del tejido social; y el fortalecimiento de las eficacias simbólicas al trabajar terapéuticamente con familias.

  8. The dilemas of the new left-wing governments in Latin America

    Directory of Open Access Journals (Sweden)

    Carlos Moreira

    2007-12-01

    Full Text Available After two decades of neoliberalism, a wave of leftist governments shakes Latin America. In just one half a decade, they have been transforming the political geography and raising four questions: 1. In what sense can one speak about homogeneous left-wave of new Latin American governments?; 2. Will they mean a change in the ways of making politics?; 3. To what extent will they give an efficient solution to the social crisis of the post market reforms stage?; and 4. Which are the main ideas and principles in order to govern a big part of Latin America from now to the next future? In order to approach these questions, do we explore "models of governability" that rise in Latin American, taking into account three dimensions: the institutional, the public policy dimension and the symbolic one. Conclusions –temporary given the recent events-, state that we are in front of a decisive process for the history of the Latin American left.

  9. Weber no Século XXI: Desafios e Dilemas de um Paradigma Weberiano

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Sell

    2014-03-01

    Full Text Available Después de décadas de intensivo trabajo de exegesis de la obra de Weber, una amplia investigación realizada en Alemania sobre este autor condujo a la caracterización de su obra en torno al tema de la racionalización. A partir de este presupuesto, una nueva generación de investigadores viene intentando formular una propuesta de actualización de la teoría weberiana, por medio de su confrontación con los principales problemas de análisis de la sociología contemporánea. ¿Cuáles son las características del "paradigma weberiano" y cómo evaluarlo en términos de agenda teórica contemporánea? Con base en estas cuestiones, se examina, en primer lugar, cómo el programa de investigación weberiano se inserta en la disputa alrededor de la articulación entre agencia (plano micro y estructura (macro en la teoría social. El segundo eje de análisis trata la teoría de la modernidad y evalúa el intento de sus intérpretes de desplegar las investigaciones weberianas del plano de la génesis al plano de la diversificación de la modernidad (modernidades múltiples.

  10. 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...

  11. Feeding and stocking up: radio-labelled food reveals exchange patterns in ants.

    OpenAIRE

    Aurélie Buffin; Damien Denis; Gaetan Van Simaeys; Serge Goldman; Jean-Louis Deneubourg

    2009-01-01

    Food sharing is vital for a large number of species, either solitary or social, and is of particular importance within highly integrated societies, such as in colonial organisms and in social insects. Nevertheless, the mechanisms that govern the distribution of food inside a complex organizational system remain unknown. Using scintigraphy, a method developed for medical imaging, we were able to describe the dynamics of food-flow inside an ant colony. We monitored the sharing process of a radi...

  12. Coevolution in host-parasite systems: behavioural strategies of slave-making ants and their hosts.

    OpenAIRE

    Foitzik, S.; DeHeer, C. J.; Hunjan, D. N.; Herbers, J. M.

    2001-01-01

    Recently, avian brood parasites and their hosts have emerged as model systems for the study of host-parasite coevolution. However, empirical studies of the highly analogous social parasites, which use the workers of another eusocial species to raise their own young, have never explicitly examined the dynamics of these systems from a coevolutionary perspective. Here, we demonstrate interpopulational variation in behavioural interactions between a socially parasitic slave-maker ant and its host...

  13. 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.

  14. Saving the injured: Rescue behavior in the termite-hunting ant Megaponera analis.

    Science.gov (United States)

    Frank, Erik Thomas; Schmitt, Thomas; Hovestadt, Thomas; Mitesser, Oliver; Stiegler, Jonas; Linsenmair, Karl Eduard

    2017-04-01

    Predators of highly defensive prey likely develop cost-reducing adaptations. The ant Megaponera analis is a specialized termite predator, solely raiding termites of the subfamily Macrotermitinae (in this study, mostly colonies of Pseudocanthotermes sp.) at their foraging sites. The evolutionary arms race between termites and ants led to various defensive mechanisms in termites (for example, a caste specialized in fighting predators). Because M. analis incurs high injury/mortality risks when preying on termites, some risk-mitigating adaptations seem likely to have evolved. We show that a unique rescue behavior in M. analis , consisting of injured nestmates being carried back to the nest, reduces combat mortality. After a fight, injured ants are carried back by their nestmates; these ants have usually lost an extremity or have termites clinging to them and are able to recover within the nest. Injured ants that are forced experimentally to return without help, die in 32% of the cases. Behavioral experiments show that two compounds, dimethyl disulfide and dimethyl trisulfide, present in the mandibular gland reservoirs, trigger the rescue behavior. A model accounting for this rescue behavior identifies the drivers favoring its evolution and estimates that rescuing enables maintenance of a 28.7% larger colony size. Our results are the first to explore experimentally the adaptive value of this form of rescue behavior focused on injured nestmates in social insects and help us to identify evolutionary drivers responsible for this type of behavior to evolve in animals.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Capital Social y Estudios Sociales de la Ciencia y la Tecnología

    Directory of Open Access Journals (Sweden)

    Ronald Cancino

    2006-01-01

    Full Text Available El artículo intenta una aproximación conceptual entre los Estudios Sociales de la Ciencia y la Tecnología, particularmente entre el llamado Constructivismo Social de Sistemas Tecnológicos y la Teoría del Círculo Crédito-Credibilidad, con algunos desarrollos conceptuales del Capital Social, específicamente las nociones de "Cierre de Relaciones", "Confianza Particularizada/Confianza Generalizada", "Dilema Social" y "Bien Público". Propone un modo de acercamiento de ambos campos de estudio para diseñar una estrategia teórico metodológica para el análisis y promoción de redes tecnocientíficas y tecnoeconómicas.

  1. 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.

  2. 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...

  3. 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.

  4. 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...

  5. The expression and impact of antifungal grooming in ants.

    Science.gov (United States)

    Reber, A; Purcell, J; Buechel, S D; Buri, P; Chapuisat, M

    2011-05-01

    Parasites can cause extensive damage to animal societies in which many related individuals frequently interact. In response, social animals have evolved diverse individual and collective defences. Here, we measured the expression and efficiency of self-grooming and allo-grooming when workers of the ant Formica selysi were contaminated with spores of the fungal entomopathogen Metarhizium anisopliae. The amount of self-grooming increased in the presence of fungal spores, which shows that the ants are able to detect the risk of infection. In contrast, the amount of allo-grooming did not depend on fungal contamination. Workers groomed all nestmate workers that were re-introduced into their groups. The amount of allo-grooming towards noncontaminated individuals was higher when the group had been previously exposed to the pathogen. Allo-grooming decreased the number of fungal spores on the surface of contaminated workers, but did not prevent infection in the conditions tested (high dose of spores and late allo-grooming). The rate of disease transmission to groomers and other nestmates was extremely low. The systematic allo-grooming of all individuals returning to the colony, be they contaminated or not, is probably a simple but robust prophylactic defence preventing the spread of fungal diseases in insect societies. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  6. Usos sociales de la religión como recurso ante la violencia: católicos, evangélicos y testigos de Jehová en Tijuana, México

    Directory of Open Access Journals (Sweden)

    Erika Valenzuela

    2014-01-01

    Full Text Available A partir de la experiencia de los creyentes cat licos, evang licos y testigos de Jehov radicados en la ciudad fronteriza de Tijuana, Baja California, se analiza en qu forma las creencias, rituales, comunidades e instituciones religiosas devienen o no un recurso relevante para hacer frente a experiencias de violencia en un contexto de acelerado incremento de la inseguridad. Concluimos que si bien en los tres casos las creencias reli giosas ocupan un importante lugar en la construcci n de la interpretaci n de la violencia, entre los cat licos dicha interpretaci n coexiste con argumentos de car cter social, entre los evang licos destaca un mayor inter s por la participaci n pol tica para frenar la insegu ridad, y entre los testigos de Jehov el car cter escatol gico resulta central e invalida toda acci n contra la violencia, que es percibida con resignaci n, como la se al inevitable del n de los tiempos.

  7. 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....

  8. 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....

  9. 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.

  10. 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...

  11. 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...

  12. 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

  13. 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 ...

  14. 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.

  15. 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.

  16. 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

  17. 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 ...

  18. 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.

  19. 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

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. Inventar o reflejar la realidad. Un dilema que compromete la credibilidad informativa de los medios de comunicación en Colombia

    Directory of Open Access Journals (Sweden)

    Germán Ortíz Leyva

    2002-01-01

    Full Text Available En un contexto en el cual la tarea de informar que ejercen los medios masivos de comunicación se cuestiona constantemente, resulta imprescindible conocer la credibilidad que tienen las empresas informativas para los diversos actores de la sociedad colombiana. Es igualmente necesario, diferenciar la credibilidad y el consumo de medios y este último, a su vez, de la verdad o falsedad que conlleva la información. El artículo parte de una reciente encuesta del Observatorio de Medios de la Facultad de Comunicación Social y Periodismo de la Universidad de La Sabana, que revela las contradicciones que se pueden dar en la realidad colombiana, pues un medio que posee altos índices de consumo, muchas veces no genera la credibilidad esperada y, a su vez, medios de bajo consumo pueden estar dirigidos por periodistas de gran credibilidad. Todo indica que la opción de los medios para ser creíbles ante sus audiencias está en que puedan abrir espacios de participación ciudadana y permitir, de manera clara, la construcción de lo público y del sentir ciudadano.

  5. 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

  6. Non-transferable signals on ant queen eggs

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Tofilski, Adam; Heinze, Jürgen

    2006-01-01

    How biological systems resolve internal conflicts is a major evolutionary question. Social insect workers cooperate but also pursue individual interests, such as laying male eggs. The rewards of this individual selfishness can be reduced by policing, such as by killing worker-laid eggs. However......, selfish individuals may evade policing. What factors prevent individuals from being able to evade policing? In the ant Pachycondyla inversa, workers kill (police) worker-laid eggs. Because the colony keeps eggs in piles and worker-laid and queen-laid eggs are chemically distinct, worker-laid eggs might...... become more acceptable once placed in the egg pile by odour transfer from touching queen-laid eggs. Here, we show that such "cue scrambling" does not occur. Worker-laid eggs that were sandwiched between three queen-laid eggs for 45 min were not more acceptable in a policing bioassay than control worker...

  7. 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.

  8. Specialization does not predict individual efficiency in an ant.

    Directory of Open Access Journals (Sweden)

    Anna Dornhaus

    2008-11-01

    Full Text Available The ecological success of social insects is often attributed to an increase in efficiency achieved through division of labor between workers in a colony. Much research has therefore focused on the mechanism by which a division of labor is implemented, i.e., on how tasks are allocated to workers. However, the important assumption that specialists are indeed more efficient at their work than generalist individuals--the "Jack-of-all-trades is master of none" hypothesis--has rarely been tested. Here, I quantify worker efficiency, measured as work completed per time, in four different tasks in the ant Temnothorax albipennis: honey and protein foraging, collection of nest-building material, and brood transports in a colony emigration. I show that individual efficiency is not predicted by how specialized workers were on the respective task. Worker efficiency is also not consistently predicted by that worker's overall activity or delay to begin the task. Even when only the worker's rank relative to nestmates in the same colony was used, specialization did not predict efficiency in three out of the four tasks, and more specialized workers actually performed worse than others in the fourth task (collection of sand grains. I also show that the above relationships, as well as median individual efficiency, do not change with colony size. My results demonstrate that in an ant species without morphologically differentiated worker castes, workers may nevertheless differ in their ability to perform different tasks. Surprisingly, this variation is not utilized by the colony--worker allocation to tasks is unrelated to their ability to perform them. What, then, are the adaptive benefits of behavioral specialization, and why do workers choose tasks without regard for whether they can perform them well? We are still far from an understanding of the adaptive benefits of division of labor in social insects.

  9. 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).

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. Disentangling environmental and heritable nestmate recognition cues in a carpenter ant

    DEFF Research Database (Denmark)

    van Zweden, Jelle S; Dreier, Stephanie; d'Ettorre, Patrizia

    2009-01-01

    Discriminating between group members and strangers is a key feature of social life. Nestmate recognition is very effective in social insects and is manifested by aggression and rejection of alien individuals, which are prohibited to enter the nest. Nestmate recognition is based on the quantitative...... variation in cuticular hydrocarbons, which can include heritable cues from the workers, as well as acquired cues from the environment or queen-derived cues. We tracked the profile of six colonies of the ant Camponotus aethiops for a year under homogeneous laboratory conditions. We performed chemical...... diagnostic power between colonies. The presence of a queen had little influence on nestmate discrimination abilities. Our results suggest that heritable cues of workers are the dominant factor influencing nestmate discrimination in these carpenter ants and highlight the importance of colony kin structure...

  15. ANTES DE QUE ANOCHEZCA. DERECHOS HUMANOS Y CLASES MEDIAS EN ARGENTINA ANTES Y EN LOS INICIOS DEL GOLPE DE ESTADO DE 1976

    Directory of Open Access Journals (Sweden)

    Sebastián CARASSAI

    2010-01-01

    Full Text Available En este trabajo se analiza el tema de los derechos humanos en Argentina antes y durante el comienzo del golpe de Estado de 1976 (1970-1977. Se argumenta que la inexistencia de una conciencia social sobre tales derechos en la primera mitad de la década y el temprano y extendido consenso en torno a lo que más tarde se llamará «teoría de los dos demonios» son dos elementos fundamentales a la hora de explicar la actitud de las clases medias no radicalizadas políticamente ante el surgimiento del discurso de los derechos humanos en Argentina.

  16. 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....

  17. Ants detect but do not discriminate diseased workers within their nest

    Science.gov (United States)

    Leclerc, Jean-Baptiste; Detrain, Claire

    2016-08-01

    Social insects have evolved an array of individual and social behaviours that limit pathogen entrance and spread within the colony. The detection of ectoparasites or of fungal spores on a nestmate body triggers their removal by allogrooming and appears as a primary component of social prophylaxis. However, in the case of fungal infection, one may wonder whether ant workers are able to detect, discriminate and keep at bay diseased nestmates that have no spores over their cuticle but which constitute a latent sanitary risk due to post-mortem corpse sporulation. Here, we investigate the ability of Myrmica rubra workers to detect and discriminate a healthy from a diseased nestmate infected by the entomopathogen Metarhizium anisopliae. During dyadic encounters in a neutral location, workers were more aggressive towards isolated sick nestmates on the 3rd post-infection day. However, no such detection or discrimination of fungus-infected nestmates occurred in a social context inside the nest or at the nest entrance. Gatekeepers never actively rejected incoming diseased nestmates that rather spontaneously isolated themselves outside the nest. Our study reveals that ant workers may detect health-dependent cues and that their `acceptance level' of sick nestmates is tunable depending on the social context. This raises questions about possible trade-offs between a social closure to pathogens and risks of erroneous rejection of healthy nestmates. Social isolation of moribund ants also appears as a widespread prophylactic strategy of social insects allowing them to reduce exposure to pathogens and to spare costs associated with the management of infected individuals.

  18. 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.

  19. 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

  20. 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

  1. Cuticular hydrocarbons correlate with queen reproductive status in native and invasive Argentine ants (Linepithema humile, Mayr)

    Science.gov (United States)

    Diaz, Mireia; Lenoir, Alain; Ivon Paris, Carolina; Boulay, Raphaël; Gómez, Crisanto

    2018-01-01

    In insect societies, chemical communication plays an important role in colony reproduction and individual social status. Many studies have indicated that cuticular hydrocarbons (CHCs) are the main chemical compounds encoding reproductive status. However, these studies have largely focused on queenless or monogynous species whose workers are capable of egg laying and have mainly explored the mechanisms underlying queen-worker or worker-worker reproductive conflicts. Less is known about what occurs in highly polygynous ant species with permanently sterile workers. Here, we used the Argentine ant as a model to examine the role of CHCs in communicating reproductive information in such insect societies. The Argentine ant is unicolonial, highly polygynous, and polydomous. We identified several CHCs whose presence and levels were correlated with queen age, reproductive status, and fertility. Our results also provide new insights into queen executions in the Argentine ant, a distinctive feature displayed by this species in its introduced range. Each spring, just before new sexuals appear, workers eliminate up to 90% of the mated queens in their colonies. We discovered that queens that survived execution had different CHC profiles from queens present before and during execution. More specifically, levels of some CHCs were higher in the survivors, suggesting that workers could eliminate queens based on their chemical profiles. In addition, queen CHC profiles differed based on season and species range (native vs. introduced). Overall, the results of this study provide new evidence that CHCs serve as queen signals and do more than just regulate worker reproduction. PMID:29470506

  2. No effect of Zn-pollution on the energy content in the black garden ant.

    Science.gov (United States)

    Grześ, Irena M; Okrutniak, Mateusz

    2016-05-01

    Social insects may display a response to environmental pollution at the colony level. The key trait of an ant colony is to share energy between castes in order to maintain the existing adult population and to feed the brood. In the present study we calorimetrically measured the energy content per body mass (J/mg) of adults and pupae of workers, males and females of the black garden ant Lasius niger. The ants were sampled from 37 wild colonies originating from 19 sites located along the metal pollution gradient established in a post-mining area in Poland. The cost of metal detoxification seen as a possible reduction in energy content with increasing pollution was found neither for pupae nor adults. However, a considerable part of variance in energy content is explained by belonging to the same colony. These findings stress the importance of colony-specific factors and/or the interaction of these factors with specific site in shaping the response of ants to metal-pollution stress. Colony-related factors may constrain possible selfish decisions of workers over energy allocation in workers and sexual castes.

  3. Towards sustainable enterprises: Improving social and environmental practices starting from the informal economy Vers des entreprises durables : Améliorer les pratiques sociales et environnementales en commençant par l’économie informelle Hacia las empresas sostenibles: Mejora de las prácticas sociales y medioambientales a partir de la economía informal

    Directory of Open Access Journals (Sweden)

    Maria Sabrina De Gobbi

    2012-05-01

    Full Text Available The goal of this paper is to present tools which allow informal firms to improve their social and environmental performance and become sustainable enterprises. The paper first provides an overview of the informal economy and sustainable enterprises from the perspective of the International Labor Organization. The methodological part consists of a presentation of tools which can be used to facilitate the transition of informal businesses to formality. Tools are divided into two groups: Those which require the active participation of private partners, and others which are based on partnerships between public and private entities. Applications of tools from experiences in different developing countries and mainly from projects run by the International Labor Organization are presented and their achievements and limits discussed.The paper concludes that a more focused approach on the informal economy should be adopted if more positive results are to be achieved in terms of improved social and environmental performance of enterprises. In addition, it highlights that the impact of actions on informal firms should always be monitored and reported even when the focus of projects is not on the informal economy.L’objectif de cet article est de présenter les outils qui permettent aux entreprises informelles d’améliorer leurs performances sociales et environnementales afin de s’inscrire dans la durabilité. Cet article s’ouvre sur un aperçu de l’économie informelle et des entreprises durables du point de vue de l’Organisation Internationale du travail. Il se poursuit par une partie méthodologique qui consiste en une présentation des outils permettant d’aider les entreprises de passer de l’état informel à l’état formel. Ces outils se répartissent en deux groupes : ceux qui nécessitent la participation active de partenaires privés et ceux basés sur le partenariat entre entités publiques et privées. L’article présente ensuite

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Alarm pheromone processing in the ant brain: an evolutionary perspective

    Directory of Open Access Journals (Sweden)

    Makoto Mizunami

    2010-06-01

    Full Text Available Social insects exhibit sophisticated communication by means of pheromones, one example of which is the use of alarm pheromones to alert nestmates for colony defense. We review recent advances in the understanding of the processing of alarm pheromone information in the ant brain. We found that information about formic acid and n-undecane, alarm pheromone components, is processed in a set of specific glomeruli in the antennal lobe of the ant Camponotus obscuripes. Alarm pheromone information is then transmitted, via projection neurons, to the lateral horn and the calyces of the mushroom body of the protocerebrum. In the lateral horn, we found a specific area where terminal boutons of alarm pheromone-sensitive projection neurons are more densely distributed than in the rest of the lateral horn. Some neurons in the protocerebrum responded specifically to formic acid or n-undecane and they may participate in the control of behavioral responses to each pheromone component. Other neurons, especially those originating from the mushroom body lobe, responded also to non-pheromonal odors and may play roles in integration of pheromonal and non-pheromonal signals. We found that a class of neurons receive inputs in the lateral horn and the mushroom body lobe and terminate in a variety of premotor areas. These neurons may participate in the control of aggressive behavior, which is sensitized by alarm pheromones and is triggered by non-pheromonal sensory stimuli associated with a potential enemy. We propose that the alarm pheromone processing system has evolved by differentiation of a part of general odor processing system.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Facultative slave-making ants Formica sanguinea label their slaves with own recognition cues instead of employing the strategy of chemical mimicry.

    Science.gov (United States)

    Włodarczyk, Tomasz; Szczepaniak, Lech

    2017-01-01

    Slave-making ant species use the host workforce to ensure normal colony functioning. Slaves are robbed as pupae from their natal nest and after eclosion, assume the parasite colony as their own. A possible factor promoting the successful integration of slaves into a foreign colony is congruence with the slave-makers in terms of cuticular hydrocarbons, which are known to play the role of recognition cues in social insects. Such an adaptation is observed in the obligate slave-making ant species, which are chemically adjusted to their slaves. To date, however, no reports have been available on facultative slave-making species, which represent an earlier stage of the evolution of slavery. Such an example is Formica sanguinea, which exploit F. fusca colonies as their main source of a slave workforce. Our results show that F. sanguinea ants have a distinct cuticular hydrocarbon profile, which contains compounds not present in free-living F. fusca ants from potential target nests. Moreover, enslaved F. fusca ants acquire hydrocarbons from their slave-making nestmates to such an extent that they become chemically differentiated from free-living, conspecific ants. Our study shows that F. sanguinea ants promote their own recognition cues in their slaves, rather than employing the strategy of chemical mimicry. Possible reasons why F. sanguinea is not chemically well adjusted to its main host species are discussed in this paper. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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...

  1. 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.

  2. Extreme queen-mating frequency and colony fission in African army ants

    DEFF Research Database (Denmark)

    Kronauer, Daniel J C; Schoning, Caspar; Pedersen, Jes S

    2004-01-01

    , which have so far been regarded as odd exceptions within the social Hymenoptera. Army ants and honeybees are fundamentally different in morphology and life history, but are the only social insects known that combine obligate multiple mating with reproduction by colony fission and extremely male......-biased sex ratios. This implies that the very high numbers of matings in both groups may be due partly to the relatively low costs of additional matings. Second, we were able to trace recent events of colony fission in four of the investigated colonies, where the genotypes of the two queens were only...

  3. ¿Los jóvenes leen menos que antes?

    OpenAIRE

    Da Pieve, Enzo

    2016-01-01

    El avance de las tecnologías y la aparición de las redes sociales nos han hecho creer que los jóvenes leen menos que antes, que han dejado de lado la escritura, los libros, las revistas o el periódico y se han entregado al dinamismo y el ocio que propicia internet. No obstante, el uso de internet, principalmente de redes sociales, ha presentado en los jóvenes una posibilidad de lectura y escritura cada vez mayor. Centro de Investigación en Lectura y Escritura (CILE)

  4. Mitigación del colapso de las cubiertas ligeras de fibrocemento ante vientos huracanados

    OpenAIRE

    Estrada Cingualbres, R. A.; Rodríguez Peña, J. C.; Lengarán Ávila, Y.; Campos Mobilla, S.

    2017-01-01

    La región del Caribe, el Golfo de México y el Estrecho de la Florida es una zona de alta vulnerabilidad ante huracanes de altas categorías. Las cubiertas ligeras son los elementos más vulnerables durante la ocurrencia de estos fenómenos, su colapso genera un gran peligro para la vida de los habitantes de estas viviendas, así como un alto impacto económico y social en las mismas y en obras sociales e industriales. El objetivo de esta investigación ha sido la caracterización de las cubiertas li...

  5. [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.

  6. 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...

  7. 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)

  8. 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.

  9. 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)

  10. 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

  11. Prudent Protomognathus and despotic Leptothorax duloticus: Differential costs of ant slavery

    Science.gov (United States)

    Hare, James F.; Alloway, Thomas M.

    2001-01-01

    The concept of ant slavery rests on the untested assumption that slave-making ants impose fitness costs on colonies of the species they raid. We tested that assumption by comparing the summertime seasonal productivity of Leptothorax spp. colonies in field exclosures without slavemakers, with a colony of the obligatory slave-making ant Protomognathus americanus, or with a colony of the obligatory slavemaker Leptothorax duloticus. Leptothorax longispinosus colonies placed in exclosures with P. americanus colonies did not differ significantly in any demographic attribute from colonies in exclosures without slavemakers. By contrast, Leptothorax curvispinosus colonies exposed to L. duloticus experienced significant reductions in dealate queens, workers, and larvae relative to control colonies exclosed without slavemakers. The pronounced difference in the impact of these slavemakers on their host-species populations correlates with differences in the behavior of the slavemakers observed in the laboratory and likely explains why P. americanus is more abundant than L. duloticus in nature. It seems that more advanced social parasites, like anatomical parasites, evolve to minimize their impact on their hosts, and thus can be regarded as “prudent social parasites.” PMID:11572933

  12. Arthropods Associate with their Red Wood ant Host without Matching Nestmate Recognition Cues.

    Science.gov (United States)

    Parmentier, Thomas; Dekoninck, Wouter; Wenseleers, Tom

    2017-07-01

    Social insect colonies provide a valuable resource that attracts and offers shelter to a large community of arthropods. Previous research has suggested that many specialist parasites of social insects chemically mimic their host in order to evade aggression. In the present study, we carry out a systematic study to test how common such chemical deception is across a group of 22 arthropods that are associated with red wood ants (Formica rufa group). In contrast to the examples of chemical mimicry documented in some highly specialized parasites in previous studies, we find that most of the rather unspecialized red wood ant associates surveyed did not use mimicry of the cuticular hydrocarbon recognition cues to evade host detection. Instead, we found that myrmecophiles with lower cuticular hydrocarbon concentrations provoked less host aggression. Therefore, some myrmecophiles with low hydrocarbon concentrations appear to evade host detection via a strategy known as chemical insignificance. Others showed no chemical disguise at all and, instead, relied on behavioral adaptations such as particular defense or evasion tactics, in order to evade host aggression. Overall, this study indicates that unspecialized myrmecophiles do not require the matching of host recognition cues and advanced strategies of chemical mimicry, but can integrate in a hostile ant nest via either chemical insignificance or specific behavioral adaptations.

  13. Tricks of the trade: Mechanism of brood theft in an ant.

    Science.gov (United States)

    Paul, Bishwarup; Annagiri, Sumana

    2018-01-01

    Thievery is ubiquitous in the animal kingdom, social insects not being an exception. Brood is invaluable for the survival of social insect colonies and brood theft is well documented in ants. In many species the stolen brood act as slaves in the thief colony as they take up tasks related to foraging, defence and colony maintenance. Slave-making (dulotic) ants are at an advantage as they gain workforce without investing in rearing immature young, and several slave-making species have been recorded in temperate regions. In the current study we investigate brood theft in a primitively eusocial ponerine ant Diacamma indicum that inhabits the tropics. In the context of colony relocation we asked how thieves steal brood and what victim colonies do to prevent theft. While exposed nests increased colonies' vulnerability, the relocation process itself did not enhance the chances of theft. Various aggressive interactions, in particular immobilization of intruders helped in preventing theft. Thieves that acted quickly, stayed furtive and stole unguarded brood were found to be successful. This comprehensive study of behavioural mechanism of theft reveals that these are the 'tricks' adopted by thieves.

  14. 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

  15. 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.

  16. 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.

  17. Diversity and transmission of gut bacteria in Atta and Acromyrmex leaf-cutting ants during development

    DEFF Research Database (Denmark)

    Zhukova, Mariya; Sapountzis, Panagiotis; Schiøtt, Morten

    2017-01-01

    . To elucidate the extent to which metamorphosis interrupts associations between bacteria and hosts, we analyzed changes in gut microbiota during development and traced the transmission routes of dominant symbionts from the egg to adult stage in the leaf-cutting ants Acromyrmex echinatior and Atta cephalotes...... was the absolute dominant bacterial species across developmental stages in Acromyrmex and we confirmed that Atta lacks Wolbachia also in the immature stages, and had mostly Mollicutes bacteria in the adult worker guts. Wolbachia in Acromyrmex appeared to be transovarially transmitted similar to transmission...... in solitary insects. In contrast, Mollicutes were socially transmitted from old workers to newly emerged callows. We found that larval and pupal guts of both ant species contained Pseudomonas and Enterobacter bacteria that are also found in fungus gardens, but hardly or not in adult workers, suggesting...

  18. Male fighting and ``territoriality'' within colonies of the ant Cardiocondyla venustula

    Science.gov (United States)

    Frohschammer, Sabine; Heinze, Jürgen

    2009-01-01

    The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males and winged disperser males. Winged males have been lost convergently in several clades, and in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting and species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males and also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest and defend “territories” against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.

  19. Male fighting and "territoriality" within colonies of the ant Cardiocondyla venustula.

    Science.gov (United States)

    Frohschammer, Sabine; Heinze, Jürgen

    2009-01-01

    The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males and winged disperser males. Winged males have been lost convergently in several clades, and in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting and species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males and also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest and defend "territories" against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.

  20. Differential regulation of the foraging gene associated with task behaviors in harvester ants

    Directory of Open Access Journals (Sweden)

    Kleeman Lindsay

    2011-08-01

    Full Text Available Abstract Background The division of labor in social insect colonies involves transitions by workers from one task to another and is critical to the organization and ecological success of colonies. The differential regulation of genetic pathways is likely to be a key mechanism involved in plasticity of social insect task behavior. One of the few pathways implicated in social organization involves the cGMP-activated protein kinase gene, foraging, a gene associated with foraging behavior in social insect species. The association of the foraging gene with behavior is conserved across diverse species, but the observed expression patterns and proposed functions of this gene vary across taxa. We compared the protein sequence of foraging across social insects and explored whether the differential regulation of this gene is associated with task behaviors in the harvester ant, Pogonomyrmex occidentalis. Results Phylogenetic analysis of the coding region of the foraging gene reveals considerable conservation in protein sequence across insects, particularly among hymenopteran species. The absence of amino acid variation in key active and binding sites suggests that differences in behaviors associated with this gene among species may be the result of changes in gene expression rather than gene divergence. Using real time qPCR analyses with a harvester ant ortholog to foraging (Pofor, we found that the brains of harvester ant foragers have a daily fluctuation in expression of foraging with mRNA levels peaking at midday. In contrast, young workers inside the nest have low levels of Pofor mRNA with no evidence of daily fluctuations in expression. As a result, the association of foraging expression with task behavior within a species changes depending on the time of day the individuals are sampled. Conclusions The amino acid protein sequence of foraging is highly conserved across social insects. Differences in foraging behaviors associated with this gene among

  1. 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

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. Feeding and stocking up: radio-labelled food reveals exchange patterns in ants.

    Science.gov (United States)

    Buffin, Aurélie; Denis, Damien; Van Simaeys, Gaetan; Goldman, Serge; Deneubourg, Jean-Louis

    2009-06-17

    Food sharing is vital for a large number of species, either solitary or social, and is of particular importance within highly integrated societies, such as in colonial organisms and in social insects. Nevertheless, the mechanisms that govern the distribution of food inside a complex organizational system remain unknown. Using scintigraphy, a method developed for medical imaging, we were able to describe the dynamics of food-flow inside an ant colony. We monitored the sharing process of a radio-labelled sucrose solution inside a nest of Formica fusca. Our results show that, from the very first load that enters the nest, food present within the colony acts as negative feedback to entering food. After one hour of the experiments, 70% of the final harvest has already entered the nest. The total foraged quantity is almost four times smaller than the expected storage capacity. A finer study of the spatial distribution of food shows that although all ants have been fed rapidly (within 30 minutes), a small area representing on average 8% of the radioactive surface holds more than 25% of the stored food. Even in rather homogeneous nests, we observed a strong concentration of food in few workers. Examining the position of these workers inside the nest, we found heavily loaded ants in the centre of the aggregate. The position of the centre of this high-intensity radioactive surface remained stable for the three consecutive hours of the experiments. We demonstrate that the colony simultaneously managed to rapidly feed all workers (200 ants fed within 30 minutes) and build up food stocks to prevent food shortage, something that occurs rather often in changing environments. Though we expected the colony to forage to its maximum capacity, the flow of food entering the colony is finely tuned to the colony's needs. Indeed the food-flow decreases proportionally to the food that has already been harvested, liberating the work-force for other tasks.

  7. 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

  8. 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.

  9. 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.

  10. 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 ...

  11. 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 ...

  12. 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 ...

  13. 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

  14. 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

  15. 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.

  16. 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)

  17. 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...

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. 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

  3. 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...

  4. 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.

  5. 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...

  6. 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....

  7. 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

  8. 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.

  9. TEORIAS DA ORIGEM E EVOLUÇÃO DA VIDA: DILEMAS E DESAFIOS NO ENSINO MÉDIO

    Directory of Open Access Journals (Sweden)

    Paulo Roberto de Araújo Porto

    2010-01-01

    Full Text Available This work analyses the social representation of high school students group in a catholic school about the origin os living things, highlighting the man and woman arising. Its was foccused trough the subject collective discourse (SCD methodology. The results shows that the analyzed group has vigorous religious characteristics althrough opened to scientific explication. Their discourses revealed religious influence, but it did not denote that those were obstacles for dread the teaching content the scientific scope. They showed, before, fault sign in approach school topic. In their social representations, the family¿s influence seems to be more important than the ones from school activities.

  10. 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

  11. Host exploitation strategies of the social parasite Maculinea alcon

    DEFF Research Database (Denmark)

    Fürst, Matthias Alois

    as model systems. These enable the study of adaptations and counter-adaptations that might evolve in the arms-race between a parasite pursuing maximum gain and a host trying to avoid exploitation. One such system is the socially parasitic butterfly Maculinea alcon and its host the ant Myrmica rubra....... Throughout the first instars M. alcon lives on a specific food plant, however, in the last instar before pupation it develops into an obligate social parasite, posing a considerably cost to its host ant colony. I here focus on the different exploitation strategies of M. alcon throughout its lifecycle...... a fitness cost to infected host ant colonies, the host ants are expected to have developed defense mechanisms in response to the presence of the social parasite. I was able to demonstrate that the efficiency of ant colonies to defend themselves against intruders depends on a multitude of often correlated...

  12. Expression patterns of a circadian clock gene are associated with age-related polyethism in harvester ants, Pogonomyrmex occidentalis

    Directory of Open Access Journals (Sweden)

    Ingram Krista K

    2009-04-01

    Full Text Available Abstract Background Recent advances in sociogenomics allow for comparative analyses of molecular mechanisms regulating the development of social behavior. In eusocial insects, one key aspect of their sociality, the division of labor, has received the most attention. Age-related polyethism, a derived form of division of labor in ants and bees where colony tasks are allocated among distinct behavioral phenotypes, has traditionally been assumed to be a product of convergent evolution. Previous work has shown that the circadian clock is associated with the development of behavior and division of labor in honeybee societies. We cloned the ortholog of the clock gene, period, from a harvester ant (Pogonomyrmex occidentalis and examined circadian rhythms and daily activity patterns in a species that represents an evolutionary origin of eusociality independent of the honeybee. Results Using real time qPCR analyses, we determined that harvester ants have a daily cyclic expression of period and this rhythm is endogenous (free-running under dark-dark conditions. Cyclic expression of period is task-specific; foragers have strong daily fluctuations but nest workers inside the nest do not. These patterns correspond to differences in behavior as activity levels of foragers show a diurnal pattern while nest workers tend to exhibit continuous locomotor activity at lower levels. In addition, we found that foragers collected in the early fall (relative warm, long days exhibit a delay in the nightly peak of period expression relative to foragers collected in the early spring (relative cold, short days. Conclusion The association of period mRNA expression levels with harvester ant task behaviors suggests that the development of circadian rhythms is associated with the behavioral development of ants. Thus, the circadian clock pathway may represent a conserved 'genetic toolkit' that has facilitated the parallel evolution of age-related polyethism and task allocation in

  13. Ex-ante Evaluation von Investitionsalternativen

    Directory of Open Access Journals (Sweden)

    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.

  14. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Anthropological contributions for thinking and acting in the health area and its ethical dilemas Contribuições da antropologia para dilemas éticos da área da saúde

    Directory of Open Access Journals (Sweden)

    Maria Cecília de Souza Minayo

    2008-04-01

    Full Text Available This paper attempts to analyze the way in which the issue of ethics in social research is dealt by institutional commissions based in biomedicine criteria. This discussion is particularly important for Social Sciences in Health, as our projects must necessarily be presented to Committees for assessment. In actual fact, Resolution Nº 196/1996 issued by the National Health Council establishes this mandatory requirement for all social areas. However, there is a question among researchers working with social issues, arguing that the health sector is moving outside its field when attempting to regulate actions in other fields of investigation. Grounded on philosophical anthropology, this paper is divided into three parts: (1 elements of anthropological foundations of ethics; (2 contributions of Anthropology to thinking about ethics and human rights in health; (3 internal and external questioning about anthropological practice. I conclude that if the ethical issue that involves human beings cannot be reduced to the procedures established by Ethics Committees, discussions in greater depth are required among social scientists on the construction of a practice based on and guided by respect for the intersubjectivity of all the players engaged in a research project.Neste artigo, busco problematizar a forma como a questão da ética em pesquisa social vem sendo tratada hoje pelas comissões institucionais inspiradas nas questões da biomedicina. Essa discussão é particularmente importante para as Ciências Sociais em Saúde pois existe uma obrigatoriedade de apresentação dos nossos projetos para avaliação dos comitês. A rigor, na concepção da Resolução 196/1996 do Conselho Nacional de Saúde, essa obrigatoriedade cobre todas as áreas sociais. No entanto, existe questionamento dos pesquisadores que lidam com o social, argumentando que o setor saúde extrapola quando tenta regular ações de outros campos de investigação. Fundamentado na

  20. Competencias emergentes del docente ante las demandas del Espacio Europeo de Educación Superior

    Directory of Open Access Journals (Sweden)

    María del Carmen Ortega Navas

    2010-01-01

    Full Text Available El inicio del proceso de Convergencia Europea ha tenido un impacto importante en el desarrollo de las competencias en el marco de la actual Sociedad del Conocimiento. En este contexto la entrada al Espacio Europeo de Educación Superior plantea dilemas para el docente universitario respecto a un nuevo concepto de enseñanza basado en dichas habilidades al que deberá adaptarse y habituarse de tal forma que le permitan dar respuesta a los nuevos retos y exigencias educativas y sociales que se plantean en el siglo XXI. El propósito de este artículo es comenzar comprendiendo qué son las competencias y cómo se clasifican para posteriormente entender cuál es el papel que deberán desempeñar los docentes en la universidad actual. Estudiaremos una de las competencias esenciales en la educación superior en nuestros días, aprender a lo largo de la vida, y terminaremos con una breve reflexión de los cambios en el papel del docente en la educación superior.The beginning of the process of European Convergence has had an important impact in the development of the competencesin the context of current knowledge society.In this context the entrance to the European Higher Education Area outlines dilemmas for the university teacher with respectto a new concept of teaching based on these abilities to which should be adapted and to be accustomed in such a way that allow to give answer to the new challenges and educational and social demands that are presented in the 21st century. The purpose of this article is to begin understandingwhat are the competences and how they are classified for subsequently understand which is the role that the teachers should perform in the current university.We will study one of the essential competencesin the higher education in our days, lifelong learning, and will finish with a brief reflectionofthe changes in the role ofthe teacherin the higher education.

  1. Non-transferable signals on ant queen eggs

    Science.gov (United States)

    D'Ettorre, Patrizia; Tofilski, Adam; Heinze, Jürgen; Ratnieks, Francis L. W.

    2006-03-01

    How biological systems resolve internal conflicts is a major evolutionary question. Social insect workers cooperate but also pursue individual interests, such as laying male eggs. The rewards of this individual selfishness can be reduced by policing, such as by killing worker-laid eggs. However, selfish individuals may evade policing. What factors prevent individuals from being able to evade policing? In the ant Pachycondyla inversa, workers kill (police) worker-laid eggs. Because the colony keeps eggs in piles and worker-laid and queen-laid eggs are chemically distinct, worker-laid eggs might become more acceptable once placed in the egg pile by odour transfer from touching queen-laid eggs. Here, we show that such “cue scrambling” does not occur. Worker-laid eggs that were sandwiched between three queen-laid eggs for 45 min were not more acceptable in a policing bioassay than control worker-laid eggs. Chemical analyses also showed that the surface hydrocarbon profile of these eggs was unchanged. Policing, therefore, is stable against this potential cheating mechanism probably because queen-laid eggs are made chemically distinct using chemicals, that are not easily transferred by physical contact.

  2. Mating with stressed males increases the fitness of ant queens.

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    Alexandra Schrempf

    Full Text Available BACKGROUND: According to sexual conflict theory, males can increase their own fitness by transferring substances during copulation that increase the short-term fecundity of their mating partners at the cost of the future life expectancy and re-mating capability of the latter. In contrast, sexual cooperation is expected in social insects. Mating indeed positively affects life span and fecundity of young queens of the male-polymorphic ant Cardiocondyla obscurior, even though males neither provide nuptial gifts nor any other care but leave their mates immediately after copulation and die shortly thereafter. PRINCIPAL FINDINGS: Here, we show that mating with winged disperser males has a significantly stronger impact on life span and reproductive success of young queens of C. obscurior than mating with wingless fighter males. CONCLUSIONS: Winged males are reared mostly under stressful environmental conditions, which force young queens to disperse and found their own societies independently. In contrast, queens that mate with wingless males under favourable conditions usually start reproducing in the safety of the established maternal nest. Our study suggests that males of C. obscurior have evolved mechanisms to posthumously assist young queens during colony founding under adverse ecological conditions.

  3. Antes de que anochezca. Derechos humanos y clases medias en Argentina antes y en los inicios del golpe de Estado de 1976

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    Sebastián CARASSAI

    2010-05-01

    Full Text Available RESUMEN: En este trabajo se analiza el tema de los derechos humanos en Argentina antes y durante el comienzo del golpe de Estado de 1976 (1970-1977. Se argumenta que la inexistencia de una conciencia social sobre tales derechos en la primera mitad de la década y el temprano y extendido consenso en torno a lo que más tarde se llamará «teoría de los dos demonios» son dos elementos fundamentales a la hora de explicar la actitud de las clases medias no radicalizadas políticamente ante el surgimiento del discurso de los derechos humanos en Argentina. ABSTRACT: This study explores the issue of human rights in Argentina in the period before and at the beginning of the 1976 coup d’état (1970-1977. It claims that the absence of a social conscience about human rights in the first part of the decade and the early and huge consensus about what later would be called «the two demons theory» are two essential elements to explain the attitude of the middle classes not involved in political struggle toward the emergence of a human rights discourse in Argentina.

  4. Social insect genomes exhibit dramatic evolution in gene composition and regulation while preserving regulatory features linked to sociality

    DEFF Research Database (Denmark)

    Simola, Daniel F.; Wissler, Lothar; Donahue, Greg

    2013-01-01

    Genomes of eusocial insects code for dramatic examples of phenotypic plasticity and social organization. We compared the genomes of seven ants, the honeybee, and various solitary insects to examine whether eusocial lineages share distinct features of genomic organization. Each ant lineage contain...

  5. Co-founding ant queens prevent disease by performing prophylactic undertaking behaviour.

    Science.gov (United States)

    Pull, Christopher D; Cremer, Sylvia

    2017-10-13

    Social insects form densely crowded societies in environments with high pathogen loads, but have evolved collective defences that mitigate the impact of disease. However, colony-founding queens lack this protection and suffer high rates of mortality. The impact of pathogens may be exacerbated in species where queens found colonies together, as healthy individuals may contract pathogens from infectious co-founders. Therefore, we tested whether ant queens avoid founding colonies with pathogen-exposed conspecifics and how they might limit disease transmission from infectious individuals. Using Lasius niger queens and a naturally infecting fungal pathogen Metarhizium brunneum, we observed that queens were equally likely to found colonies with another pathogen-exposed or sham-treated queen. However, when one queen died, the surviving individual performed biting, burial and removal of the corpse. These undertaking behaviours were performed prophylactically, i.e. targeted equally towards non-infected and infected corpses, as well as carried out before infected corpses became infectious. Biting and burial reduced the risk of the queens contracting and dying from disease from an infectious corpse of a dead co-foundress. We show that co-founding ant queens express undertaking behaviours that, in mature colonies, are performed exclusively by workers. Such infection avoidance behaviours act before the queens can contract the disease and will therefore improve the overall chance of colony founding success in ant queens.

  6. Genetic evidence for landscape effects on dispersal in the army ant Eciton burchellii.

    Science.gov (United States)

    Soare, Thomas W; Kumar, Anjali; Naish, Kerry A; O'Donnell, Sean

    2014-01-01

    Inhibited dispersal, leading to reduced gene flow, threatens populations with inbreeding depression and local extinction. Fragmentation may be especially detrimental to social insects because inhibited gene flow has important consequences for cooperation and competition within and among colonies. Army ants have winged males and permanently wingless queens; these traits imply male-biased dispersal. However, army ant colonies are obligately nomadic and have the potential to traverse landscapes. Eciton burchellii, the most regularly nomadic army ant, is a forest interior species: colony raiding activities are limited in the absence of forest cover. To examine whether nomadism and landscape (forest clearing and elevation) affect population genetic structure in a montane E. burchellii population, we reconstructed queen and male genotypes from 25 colonies at seven polymorphic microsatellite loci. Pairwise genetic distances among individuals were compared to pairwise geographical and resistance distances using regressions with permutations, partial Mantel tests and random forests analyses. Although there was no significant spatial genetic structure in queens or males in montane forest, dispersal may be male-biased. We found significant isolation by landscape resistance for queens based on land cover (forest clearing), but not on elevation. Summed colony emigrations over the lifetime of the queen may contribute to gene flow in this species and forest clearing impedes these movements and subsequent gene dispersal. Further forest cover removal may increasingly inhibit Eciton burchellii colony dispersal. We recommend maintaining habitat connectivity in tropical forests to promote population persistence for this keystone species. © 2013 John Wiley & Sons Ltd.

  7. Financing long-term care: ex ante, ex post or both?

    Science.gov (United States)

    Costa-Font, Joan; Courbage, Christophe; Swartz, Katherine

    2015-03-01

    This paper attempts to examine the heterogeneity in the public financing of long-term care (LTC) and the wide-ranging instruments in place to finance LTC services. We distinguish and classify the institutional responses to the need for LTC financing as ex ante (occurring prior to when the need arises, such as insurance) and ex post (occurring after the need arises, such as public sector and family financing). Then, we examine country-specific data to ascertain whether the two types of financing are complements or substitutes. Finally, we examine exploratory cross-national data on public expenditure determinants, specifically economic, demographic and social determinants. We show that although both ex ante and ex post mechanisms exist in all countries with advanced industrial economies and despite the fact that instruments are different across countries, ex ante and ex post instruments are largely substitutes for each other. Expenditure estimates to date indicate that the public financing of LTC is highly sensitive to a country's income, ageing of the population and the availability of informal caregiving. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Entre el perdón y el paredón: Preguntas y dilemas de la justicia ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In this way, Entre el perdón y el paredón helps not only to identify the challenges that Colombian society will have to face to overcome its current armed conflict, but also ... Angelika Rettberg, PhD, is a professor in the Department of Political Science in the Faculty of Social Sciences at the Universidad de los Andes, and is the ...

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

    Directory of Open Access Journals (Sweden)

    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

  10. 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.

  11. 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.

  12. Food-plant niche selection rather than the presence of ant nests explains oviposition patterns in the myrmecophilous butterfly genus Maculinea.

    Science.gov (United States)

    Thomas, J A; Elmes, G W

    2001-03-07

    It has been suggested that the socially parasitic butterfly Maculinea alcon detects ant odours before ovipositing on initial larval food plants near colonies of its obligate ant host Myrmica ruginodis. It has also been suggested that overcrowding on food plants near M. ruginodis is avoided by an ability to detect high egg loads, resulting in a switch to selecting plants near less suitable ant species. If confirmed, this hypothesis (H1) would have serious implications for the application of current population models aimed at the conservation of endangered Maculinea species, which are based on the null hypothesis (H0) that females randomly select food plants whose flower buds are at a precise phenological stage, making oviposition independent of ants. If H1 were wrong, practical management based upon its assumptions could lead to the extinction of protected populations. We present data for the five European species of Maculinea which show that (i) each oviposits on a phenologically restricted flower-bud stage, which accounts for the apparent host-ant-mediated niche separation in sympatric populations of Maculinea nausithous and Maculinea teleius, (ii) there is no temporal shift in oviposition by Maculinea arion in relation to host ant distribution or egg density, and (iii) oviposition patterns in 13 populations of M. alcon's closest relative, Macaulinea rebeli, conform to H0 not H1 predictions. It is concluded that conservation measures should continue to be based on H0.

  13. Pyrokinin β-neuropeptide affects necrophoretic behavior in fire ants (S. invicta), and expression of β-NP in a mycoinsecticide increases its virulence.

    Science.gov (United States)

    Fan, Yanhua; Pereira, Roberto M; Kilic, Engin; Casella, George; Keyhani, Nemat O

    2012-01-01

    Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β-neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT(50), but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed.

  14. Seasonality directs contrasting food collection behavior and nutrient regulation strategies in ants.

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    Steven C Cook

    Full Text Available Long-lived animals, including social insects, often display seasonal shifts in foraging behavior. Foraging is ultimately a nutrient consumption exercise, but the effect of seasonality per se on changes in foraging behavior, particularly as it relates to nutrient regulation, is poorly understood. Here, we show that field-collected fire ant colonies, returned to the laboratory and maintained under identical photoperiod, temperature, and humidity regimes, and presented with experimental foods that had different protein (p to carbohydrate (c ratios, practice summer- and fall-specific foraging behaviors with respect to protein-carbohydrate regulation. Summer colonies increased the amount of food collected as the p:c ratio of their food became increasingly imbalanced, but fall colonies collected similar amounts of food regardless of the p:c ratio of their food. Choice experiments revealed that feeding was non-random, and that both fall and summer ants preferred carbohydrate-biased food. However, ants rarely ate all the food they collected, and their cached or discarded food always contained little carbohydrate relative to protein. From a nutrient regulation strategy, ants consumed most of the carbohydrate they collected, but regulated protein consumption to a similar level, regardless of season. We suggest that varied seasonal food collection behaviors and nutrient regulation strategies may be an adaptation that allows long-lived animals to meet current and future nutrient demands when nutrient-rich foods are abundant (e.g. spring and summer, and to conserve energy and be metabolically more efficient when nutritionally balanced foods are less abundant.

  15. Genetic clusters and sex-biased gene flow in a unicolonial Formica ant

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    Chapuisat Michel

    2009-03-01

    Full Text Available Abstract Background Animal societies are diverse, ranging from small family-based groups to extraordinarily large social networks in which many unrelated individuals interact. At the extreme of this continuum, some ant species form unicolonial populations in which workers and queens can move among multiple interconnected nests without eliciting aggression. Although unicoloniality has been mostly studied in invasive ants, it also occurs in some native non-invasive species. Unicoloniality is commonly associated with very high queen number, which may result in levels of relatedness among nestmates being so low as to raise the question of the maintenance of altruism by kin selection in such systems. However, the actual relatedness among cooperating individuals critically depends on effective dispersal and the ensuing pattern of genetic structuring. In order to better understand the evolution of unicoloniality in native non-invasive ants, we investigated the fine-scale population genetic structure and gene flow in three unicolonial populations of the wood ant F. paralugubris. Results The analysis of geo-referenced microsatellite genotypes and mitochondrial haplotypes revealed the presence of cryptic clusters of genetically-differentiated nests in the three populations of F. paralugubris. Because of this spatial genetic heterogeneity, members of the same clusters were moderately but significantly related. The comparison of nuclear (microsatellite and mitochondrial differentiation indicated that effective gene flow was male-biased in all populations. Conclusion The three unicolonial populations exhibited male-biased and mostly local gene flow. The high number of queens per nest, exchanges among neighbouring nests and restricted long-distance gene flow resulted in large clusters of genetically similar nests. The positive relatedness among clustermates suggests that kin selection may still contribute to the maintenance of altruism in unicolonial

  16. Seasonality directs contrasting food collection behavior and nutrient regulation strategies in ants.

    Science.gov (United States)

    Cook, Steven C; Eubanks, Micky D; Gold, Roger E; Behmer, Spencer T

    2011-01-01

    Long-lived animals, including social insects, often display seasonal shifts in foraging behavior. Foraging is ultimately a nutrient consumption exercise, but the effect of seasonality per se on changes in foraging behavior, particularly as it relates to nutrient regulation, is poorly understood. Here, we show that field-collected fire ant colonies, returned to the laboratory and maintained under identical photoperiod, temperature, and humidity regimes, and presented with experimental foods that had different protein (p) to carbohydrate (c) ratios, practice summer- and fall-specific foraging behaviors with respect to protein-carbohydrate regulation. Summer colonies increased the amount of food collected as the p:c ratio of their food became increasingly imbalanced, but fall colonies collected similar amounts of food regardless of the p:c ratio of their food. Choice experiments revealed that feeding was non-random, and that both fall and summer ants preferred carbohydrate-biased food. However, ants rarely ate all the food they collected, and their cached or discarded food always contained little carbohydrate relative to protein. From a nutrient regulation strategy, ants consumed most of the carbohydrate they collected, but regulated protein consumption to a similar level, regardless of season. We suggest that varied seasonal food collection behaviors and nutrient regulation strategies may be an adaptation that allows long-lived animals to meet current and future nutrient demands when nutrient-rich foods are abundant (e.g. spring and summer), and to conserve energy and be metabolically more efficient when nutritionally balanced foods are less abundant.

  17. 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

  18. 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.

  19. The complex nest architecture of the Ponerinae ant Odontomachus chelifer

    Science.gov (United States)

    Pereira, Márlon César; Batista, Nathan Rodrigues; Rodrigues, Candida Anitta Pereira; Antonialli, William Fernando

    2018-01-01

    In social insects, nests are very important structures built to provide a protected microhabitat for immature development and food storage and are the places where most interactions between all members of a colony occur. Considering that nest architecture is an important behavioural trait that can clarify essential points of the social level of the species, here we describe the architectural model of the Ponerinae ant Odontomachus chelifer. Five subterranean nests were excavated; one of them filled with liquid cement for extraction of casts of chambers, shafts and tunnels. All nests were found in a woodland area, with Dystrophic Red Latosol soil, associated with roots of large trees and, differently from the pattern currently described for this subfamily, presented a complex structure with multiple entrances and more than one vertical shaft connected by tunnels to relatively horizontal chambers. The number of chambers varied from 24 to 77, with mean volume ranging from 200.09 cm3 to 363.79 cm3, and maximum depth of 134 cm. Worker population varied between 304 and 864 individuals with on average 8.28 cm2 of area per worker. All nests had at least one Hall, which is a relatively larger chamber serving as a distribution centre of the nest, and to our knowledge, there is no record of Ponerinae species building similar structure. All nests had chambers "paved" with pieces of decaying plant material and on the floor of some of them, we found a fungus whose identification and function are being investigated. Thus, our findings provide evidence to suggest that nests of O. chelifer can be considered complex, due to the great number and organization of chambers, shafts and connections, compared to those currently described for Ponerinae species. PMID:29298335

  20. The complex nest architecture of the Ponerinae ant Odontomachus chelifer.

    Directory of Open Access Journals (Sweden)

    Ingrid de Carvalho Guimarães

    Full Text Available In social insects, nests are very important structures built to provide a protected microhabitat for immature development and food storage and are the places where most interactions between all members of a colony occur. Considering that nest architecture is an important behavioural trait that can clarify essential points of the social level of the species, here we describe the architectural model of the Ponerinae ant Odontomachus chelifer. Five subterranean nests were excavated; one of them filled with liquid cement for extraction of casts of chambers, shafts and tunnels. All nests were found in a woodland area, with Dystrophic Red Latosol soil, associated with roots of large trees and, differently from the pattern currently described for this subfamily, presented a complex structure with multiple entrances and more than one vertical shaft connected by tunnels to relatively horizontal chambers. The number of chambers varied from 24 to 77, with mean volume ranging from 200.09 cm3 to 363.79 cm3, and maximum depth of 134 cm. Worker population varied between 304 and 864 individuals with on average 8.28 cm2 of area per worker. All nests had at least one Hall, which is a relatively larger chamber serving as a distribution centre of the nest, and to our knowledge, there is no record of Ponerinae species building similar structure. All nests had chambers "paved" with pieces of decaying plant material and on the floor of some of them, we found a fungus whose identification and function are being investigated. Thus, our findings provide evidence to suggest that nests of O. chelifer can be considered complex, due to the great number and organization of chambers, shafts and connections, compared to those currently described for Ponerinae species.