82 research outputs found

    A map of brain neuropils and fiber systems in the ant Cardiocondyla obscurior

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    A wide spectrum of occupied ecological niches and spectacular morphological adaptations make social insects a prime object for comparative neuroanatomical studies. Eusocial insects have evolved complex societies based on caste polyphenism. A diverse behavioral repertoire of morphologically distinct castes of the same species requires a high degree of plasticity in the central nervous system. We have analyzed the central brain neuropils and fiber tract systems of the worker of the ant Cardiocondyla obscurior, a model for the study of social traits. Our analysis is based on whole mount preparations of adult brains labeled with an antibody against Drosophila-Synapsin, which cross-reacts strongly with synapses in Cardiocondyla. Neuropil compartments stand out as domains with a certain texture and intensity of the anti-Synapsin signal. By contrast, fiber tracts, which are composed of bundles of axons accompanied by glia and are devoid of synapses, appear as channels or sheaths with low anti-Synapsin signal. We have generated a digital 3D atlas of the Cardiocondyla brain neuropil. The atlas provides a reference for future studies of brain polymorphisms in distinct castes, brain development or localization of neurotransmitter systems

    Convergent evolution of a labile nutritional symbiosis in ants

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    Ants are among the most successful organisms on Earth. It has been suggested that forming symbioses with nutrient-supplementing microbes may have contributed to their success, by allowing ants to invade otherwise inaccessible niches. However, it is unclear whether ants have evolved symbioses repeatedly to overcome the same nutrient limitations. Here, we address this question by comparing the independently evolved symbioses in Camponotus, Plagiolepis, Formica and Cardiocondyla ants. Our analysis reveals the only metabolic function consistently retained in all of the symbiont genomes is the capacity to synthesise tyrosine. We also show that in certain multi-queen lineages that have co-diversified with their symbiont for millions of years, only a fraction of queens carry the symbiont, suggesting ants differ in their colony-level reliance on symbiont-derived resources. Our results imply that symbioses can arise to solve common problems, but hosts may differ in their dependence on symbionts, highlighting the evolutionary forces influencing the persistence of long-term endosymbiotic mutualisms.Peer reviewe

    Angiosarcoma With Malignant Peripheral Nerve Sheath Tumour Developing in a Patient With Klippel–Trénaunay–Weber Syndrome

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    Purpose: We discuss the coexistence of Klippel–Trénaunay–Weber syndrome with various malignancies, the possible histogenetic pathways and therapeutic implications

    The Old Ladies of the Seed Harvester ant Pogonomyrmex Rugosus: Foraging Performed by Two Groups of Workers

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    We examined temporal polyethism in Pogonomyrmex rugosus, predicting a pattern of decreasing age from foragers to nest maintenance workers to individuals that were recruited to harvest a temporary food source. Nest maintenance workers were younger than foragers, as indicated by their heavier mass and lower mandibular wear. In contrast, recruited foragers were similar in mass to foragers but they displayed higher mandibular wear, suggesting that they were at least as old as foragers. Longevity estimates for marked individuals of these two latter task groups showed mixed results. Higher mandibular wear of recruited foragers suggests that they did not follow the normal sequence for temporal polyethism, but rather that they functioned as seed-millers, which should more quickly abrade their dentition. This would be the first demonstration of specialist milling individuals in a monomorphic seed-harvester ant

    Psychosoziale Unterstützung während der COVID-19-Pandemie: interdisziplinäres Versorgungskonzept an einem Universitätsklinikum

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    BACKGROUND Since the beginning of the outbreak, the COVID-19 pandemic has caused an increased demand for psychosocial support for patients, their family members, and healthcare workers. Concurrently, possibilities to provide this support have been hindered. Quarantine, social isolation, and SARS-CoV\hbox-2 infections represent new and severe stressors that have to be addressed with innovative psychosocial care. OBJECTIVE AND METHOD This article describes the COVID-19 psychosocial first aid concept at the University Hospital Munich (LMU Klinikum) developed by an interdisciplinary team of psychiatric, psychological, spiritual care, psycho-oncological, and palliative care specialists. RESULTS A~new psychosocial first aid model has been implemented for COVID-19 inpatients, family members, and hospital staff consisting of five elements. CONCLUSION The concept integrates innovative and sustainable ideas, e.g. telemedicine-based approaches and highlights the importance of multidisciplinary collaboration to cope with challenges in the healthcare system.Hintergrund Die COVID-19-Pandemie hat seit ihrem Beginn zu einem erhöhten psychosozialen Unterstützungsbedarf bei Patient*innen, Angehörigen und Mitarbeiter*innen geführt und übliche Wege klinischer Versorgung erschwert. Sowohl Quarantäne- und Isolationsmaßnahmen als auch SARS-CoV-2-Infektionen und -Erkrankungen sind zu neuen und erheblichen Belastungsfaktoren geworden, die in neuen Ansätzen der Versorgung adressiert werden müssen. Ziel der Arbeit und Methode Dieser Beitrag beschreibt die Entwicklung des Konzeptes Psychosoziale Versorgung COVID-19 am LMU-Klinikum in München durch ein interdisziplinäres Team von Psychiater*innen, Psycholog*innen, Seelsorger*innen, Psychoonkolog*innen und Palliativmediziner*innen. Ergebnis Das neue Versorgungsmodell zur psychosozialen Unterstützung wurde für stationäre COVID-19-Patient*innen des Klinikums, deren Angehörige und Mitarbeiter*innen bestehend aus fünf Elementen implementiert. Diskussion Das Angebot integriert innovative und nachhaltige Ansätze, wie den Einsatz telemedizinischer Interventionen, und unterstreicht den Wert interdisziplinärer Zusammenarbeit zur Bewältigung von Herausforderungen im Gesundheitswesen

    Decreased Functional Diversity and Biological Pest Control in Conventional Compared to Organic Crop Fields

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    Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (15 organic vs. 15 conventional) and recorded vascular plants, pollinators, aphids and their predators. Further, five conventional fields which were treated with insecticides were compared with 10 non-treated conventional fields. Organic fields had five times higher plant species richness and about twenty times higher pollinator species richness compared to conventional fields. Abundance of pollinators was even more than one-hundred times higher on organic fields. In contrast, the abundance of cereal aphids was five times lower in organic fields, while predator abundances were three times higher and predator-prey ratios twenty times higher in organic fields, indicating a significantly higher potential for biological pest control in organic fields. Insecticide treatment in conventional fields had only a short-term effect on aphid densities while later in the season aphid abundances were even higher and predator abundances lower in treated compared to untreated conventional fields. Our data indicate that insecticide treatment kept aphid predators at low abundances throughout the season, thereby significantly reducing top-down control of aphid populations. Plant and pollinator species richness as well as predator abundances and predator-prey ratios were higher at field edges compared to field centres, highlighting the importance of field edges for ecosystem services. In conclusion organic farming increases biodiversity, including important functional groups like plants, pollinators and predators which enhance natural pest control. Preventative insecticide application in conventional fields has only short-term effects on aphid densities but long-term negative effects on biological pest control. Therefore conventional farmers should restrict insecticide applications to situations where thresholds for pest densities are reached

    Detection of segregation distortion loci in triticale (x Triticosecale Wittmack) based on a high-density DArT marker consensus genetic linkage map

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    <p>Abstract</p> <p>Background</p> <p>Triticale is adapted to a wide range of abiotic stress conditions, is an important high-quality feed stock and produces similar grain yield but more biomass compared to other crops. Modern genomic approaches aimed at enhancing breeding progress in cereals require high-quality genetic linkage maps. Consensus maps are genetic maps that are created by a joint analysis of the data from several segregating populations and different approaches are available for their construction. The phenomenon that alleles at a locus deviate from the Mendelian expectation has been defined as segregation distortion. The study of segregation distortion is of particular interest in doubled haploid (DH) populations due to the selection pressure exerted on the plants during the process of their establishment.</p> <p>Results</p> <p>The final consensus map, constructed out of six segregating populations derived from nine parental lines, incorporated 2555 DArT markers mapped to 2602 loci (1929 unique). The map spanned 2309.9 cM with an average number of 123.9 loci per chromosome and an average marker density of one unique locus every 1.2 cM. The R genome showed the highest marker coverage followed by the B genome and the A genome. In general, locus order was well maintained between the consensus linkage map and the component maps. However, we observed several groups of loci for which the colinearity was slightly uneven. Among the 2602 loci mapped on the consensus map, 886 showed distorted segregation in at least one of the individual mapping populations. In several DH populations derived by androgenesis, we found chromosomes (2B, 3B, 1R, 2R, 4R and 7R) containing regions where markers exhibited a distorted segregation pattern. In addition, we observed evidence for segregation distortion between pairs of loci caused either by a predominance of parental or recombinant genotypes.</p> <p>Conclusions</p> <p>We have constructed a reliable, high-density DArT marker consensus genetic linkage map as a basis for genomic approaches in triticale research and breeding, for example for multiple-line cross QTL mapping experiments. The results of our study exemplify the tremendous impact of different DH production techniques on allele frequencies and segregation distortion covering whole chromosomes.</p
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