247 research outputs found

    Can we manage first impressions in cooperation problems? An experiment

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    We study how cooperative behavior reacts to selective (favorable or unfavorable) pre-play information about the cooperativeness of other, unrelated groups within an experimental framework that is sufficiently rich for conflicting behavioral norms to emerge. We find that cooperation crucially depends on pre-play information, coinciding with a change in initial beliefs. Over time, behavior within both types of groups becomes increasingly homogeneous, indicating the formation of two rather different social norms, depending on whether pre-play information was favorable or unfavorable. In addition, we find unfavorable information to substantially reduce the effectiveness of peer punishment. For these differences to emerge it is immaterial whether each member or only one member of a four-person group receives the pre-play information.experiment, information, Norms, cooperation, Effectiveness of Sanctions, Expectations

    Home, sweet home : die Entwicklung des Handelsvolumens deutscher Aktien im Ausland

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    Wir untersuchen, in welchem Ausmaß die Aktien deutscher Unternehmen im Zeitverlauf an ausländischen Börsen gehandelt werden. Es zeigt sich – nach anfänglich bedeutsamer Handelsaktivität im Ausland – ein ausgeprägter Rückfluss-Effekt nach Deutschland. Zweitnotierungen an ausländischen Börsen dienen der Verbreiterung der Aktionärsbasis und somit der Senkung der Kapitalkosten und letztendlich der Steigerung des Unternehmenswertes. Dazu ist ein ausreichendes Handelsvolumen an der ausländischen Börse unabdinglich. Daran gemessen sind die Auslandsnotierungen deutscher Unternehmen nicht erfolgreich. Dies ist jedoch nicht im gleichen Ausmaß für alle Unternehmen der Fall. Kleinere, wachsende Unternehmen und Unternehmen mit höherem Anteil des Auslandsumsatzes am Gesamtumsatz werden relativ stärker im Ausland gehandelt

    Women in Private Practice

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    Current View on Phytoplasma Genomes and Encoded Metabolism

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    Phytoplasmas are specialised bacteria that are obligate parasites of plant phloem tissue and insects. These bacteria have resisted all attempts of cell-free cultivation. Genome research is of particular importance to analyse the genetic endowment of such bacteria. Here we review the gene content of the four completely sequenced ‘Candidatus Phytoplasma' genomes that include those of ‘Ca. P. asteris' strains OY-M and AY-WB, ‘Ca. P. australiense,' and ‘Ca. P. mali'. These genomes are characterized by chromosome condensation resulting in sizes below 900 kb and a G + C content of less than 28%. Evolutionary adaption of the phytoplasmas to nutrient-rich environments resulted in losses of genetic modules and increased host dependency highlighted by the transport systems and limited metabolic repertoire. On the other hand, duplication and integration events enlarged the chromosomes and contribute to genome instability. Present differences in the content of membrane and secreted proteins reflect the host adaptation in the phytoplasma strains. General differences are obvious between different phylogenetic subgroups. ‘Ca. P. mali' is separated from the other strains by its deviating chromosome organization, the genetic repertoire for recombination and excision repair of nucleotides or the loss of the complete energy-yielding part of the glycolysis. Apart from these differences, comparative analysis exemplified that all four phytoplasmas are likely to encode an alternative pathway to generate pyruvate and ATP

    Draft Genome Sequence of " Candidatus Phytoplasma pruni" (X-Disease Group, Subgroup 16SrIII-B) Strain ChTDIII from Argentina

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    Herein, we report the draft genome sequence of “Candidatus Phytoplasma pruni” strain ChTDIII (subgroup 16SrIII-B). The final assembly consists of 790,517 nucleotides organized in 67 contigs (minimal size, 1 kb), with a G+C content of 29.4% and encoding 672 proteins.Instituto de Patología VegetalFil: Fernandez, Franco Daniel . Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Fernandez, Franco Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFYMA); Argentina.Fil: Zübert, Christina. University of Hohenheim. Integrative Infection Biology Crops-Livestock; AlemaniaFil: Huettel, Bruno. Max Planck Genome Centre Cologne. Max Planck Institute for Plant Breeding; AlemaniaFil: Kube, Michael. University of Hohenheim. Integrative Infection Biology Crops-Livestock; AlemaniaFil: Conci, Luis Rogelio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Conci, Luis Rogelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFYMA); Argentina

    Analysis of a normalised expressed sequence tag (EST) library from a key pollinator, the bumblebee Bombus terrestris

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    <p>Abstract</p> <p>Background</p> <p>The bumblebee, <it>Bombus terrestris </it>(Order Hymenoptera), is of widespread importance. This species is extensively used for commercial pollination in Europe, and along with other <it>Bombus </it>spp. is a key member of natural pollinator assemblages. Furthermore, the species is studied in a wide variety of biological fields. The objective of this project was to create a <it>B. terrestris </it>EST resource that will prove to be valuable in obtaining a deeper understanding of this significant social insect.</p> <p>Results</p> <p>A normalised cDNA library was constructed from the thorax and abdomen of <it>B. terrestris </it>workers in order to enhance the discovery of rare genes. A total of 29'428 ESTs were sequenced. Subsequent clustering resulted in 13'333 unique sequences. Of these, 58.8 percent had significant similarities to known proteins, with 54.5 percent having a "best-hit" to existing Hymenoptera sequences. Comparisons with the honeybee and other insects allowed the identification of potential candidates for gene loss, pseudogene evolution, and possible incomplete annotation in the honeybee genome. Further, given the focus of much basic research and the perceived threat of disease to natural and commercial populations, the immune system of bumblebees is a particularly relevant component. Although the library is derived from unchallenged bees, we still uncover transcription of a number of immune genes spanning the principally described insect immune pathways. Additionally, the EST library provides a resource for the discovery of genetic markers that can be used in population level studies. Indeed, initial screens identified 589 simple sequence repeats and 854 potential single nucleotide polymorphisms.</p> <p>Conclusion</p> <p>The resource that these <it>B. terrestris </it>ESTs represent is valuable for ongoing work. The ESTs provide direct evidence of transcriptionally active regions, but they will also facilitate further functional genomics, gene discovery and future genome annotation. These are important aspects in obtaining a greater understanding of this key pollinator species.</p

    Expresión diferencial de genes en Pyropia columbina (Bangiales, Rhodophyta) bajo hidratación y desecación natural

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    Indexación: Web of Science; Scielo.RESUMEN. En Zonas Costeras rocosas, la desecación es gatillada porción Cambios Diarios en los Niveles de marea, y la Evidencia indica experimental de Me Distribución de las algas en la zona intermareal no está Relacionada estafa do palabra capacidad, párr tolerar la desecación. En Este Contexto, la Presencia de Pyropia columbina en la zona alta del intermareal sí Explica Por Su excepcional tolerancia fisiológica a la desecación. Este Estudio explora las Vías Metabólicas involucradas en la tolerancia a la desecación en P. columbina, un Través de la Caracterización de do transcriptoma Bajo Condiciones de hidratación contrastantes. Se obtuvó 1410 TER provenientes de dos Librerías de substracción de ADNc de frondas Naturalmente hidratadas y desecadas. Los transcriptomas de emba Librerías contienen transcritos de Diversas Rutas Metabólicas Relacionadas a la tolerancia. Entre el los transcritos expresados ​​15% estan involucrados en la Síntesis de Proteínas, do Procesamiento y degradacion, 14,4% Asociados un Fotosíntesis y cloroplasto, el 13,1% una mitocondrial Respiración and function, 10,6% al metabolism de la Pared Celular y 7,5% a la Actividad ANTIOXIDANTE, Proteínas chaperonas y factors de Defensa (catalasa, tiorredoxina, Proteínas de choque térmico, P450 citocromo). In Ambás Librerías sí DESTACA La Presencia De genes / Proteínas no descritos en algas. Proporciona Información This El Primer Trabajo molecular Que Estudia la tolerancia a desecación en P. columbina y Sus Resultados Ayudan a explicar los patrones clásicos de Distribución descritos párr algas en la zona intermareal. Palabras clave: Pyropia, desecación porción Estrés, EST, macroalgas, transcriptómica, Proteínas.ABSTRACT. In rocky shores, desiccation is triggered by daily tide changes, and experimental evidence suggests that local distribution of algal species across the intertidal rocky zone is related to their capacity to tolerate desiccation. In this context, the permanence of Pyropia columbina in the high intertidal rocky zone is explained by its exceptional physiological tolerance to desiccation. This study explored the metabolic pathways involved in tolerance to desiccation in the Chilean P. columbina, by characterizing its transcriptome under contrasting conditions of hydration. We obtained 1,410 ESTs from two subtracted cDNA libraries in naturally hydrated and desiccated fronds. Results indicate that transcriptome from both libraries contain transcripts from diverse metabolic pathways related to tolerance. Among the transcripts differentially expressed, 15% appears involved in protein synthesis, processing and degradation, 14.4% are related to photosynthesis and chloroplast, 13.1% to respiration and mitochondrial function (NADH dehydrogenase and cytochrome c oxidase proteins), 10.6% to cell wall metabolism, and 7.5% are involved in antioxidant activity, chaperone and defense factors (catalase, thioredoxin, heat shock proteins, cytochrome P450). Both libraries highlight the presence of genes/proteins never described before in algae. This information provides the first molecular work regarding desiccation tolerance in P. columbina, and helps, to some extent, explaining the classical patterns of ecological distribution described for algae across the intertidal zone.http://ref.scielo.org/jm5rc

    Ultraviolet-visible diode-array spectrophotometer as a detector for gas chromatography

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    An ultraviolet-visible diode-array spectrophotometer is used as a detector for gas chromatography. This detector can provide a full u.v.-visible spectrum of each compound as it elutes from the column, thus enhancing discrimination between incompletely separated components. A discrimination of ca. 1:5000 could be achieved for a mixture of toluene and benzene. The detection limit is comparable to that of the thermal conductivity detector, i.e., about 0.5 [mu]g for the various components. The detector is particularly useful when gases other than helium are used because the sensitivity does not depend on the gas used.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25682/1/0000236.pd

    First Impressions are More Important than Early Intervention Qualifying Broken Windows Theory in the Lab

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    Broken Windows: the metaphor has changed New York and Los Angeles. Yet it is far from undisputed whether the broken windows policy was causal for reducing crime. In a series of lab experiments we put two components of the theory to the test. We show that first impressions and early punishment of antisocial behaviour are independently and jointly causal for cooperativeness. The effect of good first impressions and of early vigilance cannot be explained with, but adds to, participants’ initial level of benevolence. Mere impression management is not strong enough to maintain cooperation. Cooperation stabilizes if good first impressions are combined with some risk of sanctions. Yet if we control for first impressions, early vigilance only has a small effect. The effect vanishes over time.
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