13 research outputs found

    Phylogeny and evolution of the Heterobranchia (Mollusca, Gastropoda)

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    Many questions regarding gastropod phylogeny have not yet been answered like the molecular confirmation of the Heterobranchia concept based on morphological studies from Haszprunar (1985a; 1988). This taxon contains the “Lower Heterobranchia” with several “primitive” or “basal” members) and the Euthyneura (with the Opisthobranchia and Pulmonata). Phylogenetic relationships of subgroups within the Heterobranchia have not been satisfactorily resolved and monophyly of some taxa within the Heterobranchia (e.g. Opisthobranchia) is questionable. Moreover, most of the “Lower Heterobranchia” have not been included in former molecular studies. In order to resolve phylogenetic relationships within the Heterobranchia, I pursued a molecular systematic approach by sequencing and analysing a variety of genetic markers (including nuclear 28S rDNA + 18S rDNA and mitochondrial 16S rDNA + COI sequences). Maximum likelihood as well as Bayesian inference methods were used for phylogenetic reconstruction. The data were investigated a priori to tree reconstruction in order to find the most appropriate dataset for reconstructing heterobranch phylogeny. A variety of statistical tests (like Chi-Square-Test or Relative-Rate-Test) were applied and the substitution saturation was measured. The Relative-Rate-Test revealed the highest evolution rates within the “Lower Heterobranchia” (Omalogyra sp., Omalogyra fusca, Murchisonella sp., Ebala sp. and Architectonica perspectiva) and Opisthobranchia (Hyalocylis striata). Furthermore, many of the nucleotide positions show a high degree of substitution saturation. Additionally, bipartitions (splits) in the alignment were examined and visualized by split network analyses to estimate data quality. A high level of conflict indicated by many parallel edges of the same lengths could be observed in the neighbournet graphs. Moreover, several taxa with long terminal branches could be identified in all three datasets belonging to the Vetigastropoda, Caenogastropoda, “Lower Heterobranchia” or Opisthobranchia (Nudipleura). All phylogenetic analyses revealed a monophyletic Heterobranchia. Within the Heterobranchia several well supported clades could be resolved. However, the traditional classification based on morphological data could not be confirmed due to paraphyletic Euthyneura (because of the inclusion of the Pyramidellidae and Glacidorboidea) as well as paraphyletic Pulmonata and polyphyletic Opisthobranchia. Based on the phylogenetic inferred evolutionary trends regarding habitat colonisation or character complexes could be deduced. A case study was conducted in order to estimate divergence ages using a “relaxed” molecular clock approach with fossils as minimum age constraints. However, due to large 95% confidence intervals a precise dating of the nodes was not possible. Hence, the results are considered as preliminary. To test the plausibility of the newly obtained hypotheses, the results were evaluated a posteriori using a hypothesis test and secondary structures of the complete 18S rRNA and 28S rRNA. Secondary structure motifs were found within domain 43 and E23 2 &5 of the 18S rRNA as well as within domain E11 and G5_1 of the 28S rRNA, which contain phylogenetic signals to support various groups within the Heterobranchia. In addition, taxon specific motifs were found separating the Vetigastropoda from the Caenogastropoda and Heterobranchia, indicating a possible application of the secondary structure of 18S rRNA and 28S rRNA to reveal phylogenetic relationships at higher taxonomic levels such as Gastropoda or even Mollusca. The utility of the newly invented software RNAsalsa for the reconstruction of secondary structures was tested. The obtained structures were used to adjust evolutionary models specific to rRNA stem (paired basepairs) and loop (unpaired basepairs) regions with the intention of improving phylogenetic results. This approach proved unsuccessful. This molecular phylogenetic investigation provides the most comprehensive molecular study of Heterobranchia relationships to date. Substantial insights into the evolution and phylogeny of this enigmatic taxon have been gained

    From sea to land and beyond : new insights into the evolution of euthyneuran Gastropoda (Mollusca)

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    Background The Euthyneura are considered to be the most successful and diverse group of Gastropoda. Phylogenetically, they are riven with controversy. Previous morphology-based phylogenetic studies have been greatly hampered by rampant parallelism in morphological characters or by incomplete taxon sampling. Based on sequences of nuclear 18S rRNA and 28S rRNA as well as mitochondrial 16S rRNA and COI DNA from 56 taxa, we reconstructed the phylogeny of Euthyneura utilising Maximum Likelihood and Bayesian inference methods. The evolution of colonization of freshwater and terrestrial habitats by pulmonate Euthyneura, considered crucial in the evolution of this group of Gastropoda, is reconstructed with Bayesian approaches. Results We found several well supported clades within Euthyneura, however, we could not confirm the traditional classification, since Pulmonata are paraphyletic and Opistobranchia are either polyphyletic or paraphyletic with several clades clearly distinguishable. Sacoglossa appear separately from the rest of the Opisthobranchia as sister taxon to basal Pulmonata. Within Pulmonata, Basommatophora are paraphyletic and Hygrophila and Eupulmonata form monophyletic clades. Pyramidelloidea are placed within Euthyneura rendering the Euthyneura paraphyletic. Conclusion Based on the current phylogeny, it can be proposed for the first time that invasion of freshwater by Pulmonata is a unique evolutionary event and has taken place directly from the marine environment via an aquatic pathway. The origin of colonisation of terrestrial habitats is seeded in marginal zones and has probably occurred via estuaries or semi-terrestrial habitats such as mangroves

    Patients’ Satisfaction by SmileInTM Totems in Radiotherapy: A Two-Year Mono-Institutional Experience

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    Background: Patient’s satisfaction is recognized as an indicator to monitor quality in healthcare services. Patient-reported experience measures (PREMs) may contribute to create a benchmark of hospital performance by assessing quality and safety in cancer care. Methods: The areas of interest assessed were: patient-centric welcome perception (PCWP), punctuality, professionalism and comfort using the Lean Six Sigma (LSS) methodology. The RAMSI (Radioterapia Amica Mia SmileINTM (SI) My Friend RadiotherapySI), project provided for the placement of SI totems with four push buttons using HappyOrNot technology in a high-volume radiation oncology (RO) department. The SI technology was implemented in the RO department of the Fondazione Policlinico Universitario A. Gemelli IRCCS. SI totems were installed in different areas of the department. The SI Experience Index was collected, analyzed and compared. Weekly and monthly reports were created showing hourly, daily and overall trends. Results: From October 2017 to November 2019, a total of 42,755 votes were recorded: 8687, 10,431, 18,628 and 5009 feedback items were obtained for PCWP, professionalism, punctuality, and comfort, respectively. All areas obtained a SI-approved rate ≥ 8.0 Conclusions: The implementation of the RAMSI system proved to be doable according to the large amount of feedback items collected in a high-volume clinical department. The application of the LSS methodology led to specific corrective actions such as modification of the call-in-clinic system during operations planning. In order to provide healthcare optimization, a multicentric and multispecialty network should be defined in order to set up a benchmar

    der Johann Wolfgang Goethe – Universität in Frankfurt am Main von

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    über den Weg erzählen als der Hase. Bernd StrombergTable of contents Table of contents List of figures.............................................................................................................................. I List of tables............................................................................................................................. III List of appendices..................................................................................................................... IV List of abbreviations (in alphabetical order)............................................................................. V Zusammenfassung.................................................................................................................... VI Abstract.................................................................................................................................... XI 1. General introduction....................................................................................................... 1 2. A priori evaluation of data quality..............................................................................

    Social competency in children with hearing loss

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    This qualitative research study explored the perceptions of occupational therapists regarding social competency needs of children with hearing loss. Four participants who treated children that are hard of hearing participated in this study. Data was collected by interviews that generated presumptions using comparisons. Interviews focused on occupational therapists perceptions regarding social skills in this population. Four themes emerged from the data. 1. Children who are hard of hearing show deficits in social competency skills, as described by occupational therapists, 2. The inclusion of social skills as a focus of occupational therapy treatment was inconsistent, 3. The treatment of children with hearing losses fell clearly into the occupational therapy domain of practice but required a special skills set, and 4. Occupational therapy practice for children who are hard of hearing incorporates a variety of intervention approaches including health promotion, remediation, maintenance, compensation, and prevention of disabilities

    From sea to land and beyond – New insights into the evolution of euthyneuran Gastropoda (Mollusca)

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    Abstract Background The Euthyneura are considered to be the most successful and diverse group of Gastropoda. Phylogenetically, they are riven with controversy. Previous morphology-based phylogenetic studies have been greatly hampered by rampant parallelism in morphological characters or by incomplete taxon sampling. Based on sequences of nuclear 18S rRNA and 28S rRNA as well as mitochondrial 16S rRNA and COI DNA from 56 taxa, we reconstructed the phylogeny of Euthyneura utilising Maximum Likelihood and Bayesian inference methods. The evolution of colonization of freshwater and terrestrial habitats by pulmonate Euthyneura, considered crucial in the evolution of this group of Gastropoda, is reconstructed with Bayesian approaches. Results We found several well supported clades within Euthyneura, however, we could not confirm the traditional classification, since Pulmonata are paraphyletic and Opistobranchia are either polyphyletic or paraphyletic with several clades clearly distinguishable. Sacoglossa appear separately from the rest of the Opisthobranchia as sister taxon to basal Pulmonata. Within Pulmonata, Basommatophora are paraphyletic and Hygrophila and Eupulmonata form monophyletic clades. Pyramidelloidea are placed within Euthyneura rendering the Euthyneura paraphyletic. Conclusion Based on the current phylogeny, it can be proposed for the first time that invasion of freshwater by Pulmonata is a unique evolutionary event and has taken place directly from the marine environment via an aquatic pathway. The origin of colonisation of terrestrial habitats is seeded in marginal zones and has probably occurred via estuaries or semi-terrestrial habitats such as mangroves.</p
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