42 research outputs found

    Phylogenetic relationships in Cortinarius, section Calochroi, inferred from nuclear DNA sequences

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    <p>Abstract</p> <p>Background</p> <p>Section <it>Calochroi </it>is one of the most species-rich lineages in the genus <it>Cortinarius </it>(Agaricales, Basidiomycota) and is widely distributed across boreo-nemoral areas, with some extensions into meridional zones. Previous phylogenetic studies of <it>Calochroi </it>(incl. section <it>Fulvi</it>) have been geographically restricted; therefore, phylogenetic and biogeographic relationships within this lineage at a global scale have been largely unknown. In this study, we obtained DNA sequences from a nearly complete taxon sampling of known species from Europe, Central America and North America. We inferred intra- and interspecific phylogenetic relationships as well as major morphological evolutionary trends within section <it>Calochroi </it>based on 576 ITS sequences, 230 ITS + 5.8S + D1/D2 sequences, and a combined dataset of ITS + 5.8S + D1/D2 and RPB1 sequences of a representative subsampling of 58 species.</p> <p>Results</p> <p>More than 100 species were identified by integrating DNA sequences with morphological, macrochemical and ecological data. <it>Cortinarius </it>section <it>Calochroi </it>was consistently resolved with high branch support into at least seven major lineages: <it>Calochroi</it>, <it>Caroviolacei</it>, <it>Dibaphi</it>, <it>Elegantiores</it>, <it>Napi</it>, <it>Pseudoglaucopodes </it>and <it>Splendentes</it>; whereas <it>Rufoolivacei </it>and <it>Sulfurini </it>appeared polyphyletic. A close relationship between <it>Dibaphi</it>, <it>Elegantiores</it>, <it>Napi </it>and <it>Splendentes </it>was consistently supported. Combinations of specific morphological, pigmentation and molecular characters appear useful in circumscribing clades.</p> <p>Conclusion</p> <p>Our analyses demonstrate that <it>Calochroi </it>is an exclusively northern hemispheric lineage, where species follow their host trees throughout their natural ranges within and across continents. Results of this study contribute substantially to defining European species in this group and will help to either identify or to name new species occurring across the northern hemisphere. Major groupings are in partial agreement with earlier morphology-based and molecular phylogenetic hypotheses, but some relationships were unexpected, based on external morphology. In such cases, their true affinities appear to have been obscured by the repeated appearance of similar features among distantly related species. Therefore, further taxonomic studies are needed to evaluate the consistency of species concepts and interpretations of morphological features in a more global context. Reconstruction of ancestral states yielded two major evolutionary trends within section <it>Calochroi</it>: (1) the development of bright pigments evolved independently multiple times, and (2) the evolution of abruptly marginate to flattened stipe bulbs represents an autapomorphy of the <it>Calochroi </it>clade.</p

    Mapping the EQ-5D index by UPDRS and PDQ-8 in patients with Parkinson’s disease

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    Background: Clinical studies employ the Unified Parkinson’s Disease Rating Scale (UPDRS) to measure the severity of Parkinson’s disease. Evaluations often fail to consider the health-related quality of life (HrQoL) or apply disease-specific instruments. Health-economic studies normally use estimates of utilities to calculate quality-adjusted life years. We aimed to develop an estimation algorithm for EuroQol- 5 dimensions (EQ-5D)-based utilities from the clinical UPDRS or disease-specific HrQoL data in the absence of original utilities estimates. Methods: Linear and fractional polynomial regression analyses were performed with data from a study of Parkinson’s disease patients (n=138) to predict the EQ-5D index values from UPDRS and Parkinson’s disease questionnaire eight dimensions (PDQ-8) data. German and European weights were used to calculate the EQ-5D index. The models were compared by R2, the root mean square error (RMS), the Bayesian information criterion, and Pregibon’s link test. Three independent data sets validated the models. Results: The regression analyses resulted in a single best prediction model (R2: 0.713 and 0.684, RMS: 0.139 and 13.78 for indices with German and European weights, respectively) consisting of UPDRS subscores II, III, IVa-c as predictors. When the PDQ-8 items were utilised as independent variables, the model resulted in an R2 of 0.60 and 0.67. The independent data confirmed the prediction models. Conclusion: The best results were obtained from a model consisting of UPDRS subscores II, III, IVa-c. Although a good model fit was observed, primary EQ-5D data are always preferable. Further validation of the prediction algorithm within large, independent studies is necessary prior to its generalised use

    The OSCAR-MP Consensus Criteria for Quality Assessment of Retinal Optical Coherence Tomography Angiography

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    Background and Objectives Optical coherence tomography angiography (OCTA) is a noninvasive high-resolution imaging technique for assessing the retinal vasculature and is increasingly used in various ophthalmologic, neuro-ophthalmologic, and neurologic diseases. To date, there are no validated consensus criteria for quality control (QC) of OCTA. Our study aimed to develop criteria for OCTA quality assessment. Methods To establish criteria through (1) extensive literature review on OCTA artifacts and image quality to generate standardized and easy-to-apply OCTA QC criteria, (2) application of OCTA QC criteria to evaluate interrater agreement, (3) identification of reasons for interrater disagreement, revision of OCTA QC criteria, development of OCTA QC scoring guide and training set, and (4) validation of QC criteria in an international, interdisciplinary multicenter study. Results We identified 7 major aspects that affect OCTA quality: (O) obvious problems, (S) signal strength, (C) centration, (A) algorithm failure, (R) retinal pathology, (M) motion artifacts, and (P) projection artifacts. Seven independent raters applied the OSCAR-MP criteria to a set of 40 OCTA scans from people with MS, Sjogren syndrome, and uveitis and healthy individuals. The interrater kappa was substantial (κ 0.67). Projection artifacts were the main reason for interrater disagreement. Because artifacts can affect only parts of OCTA images, we agreed that prior definition of a specific region of interest (ROI) is crucial for subsequent OCTA quality assessment. To enhance artifact recognition and interrater agreement on reduced image quality, we designed a scoring guide and OCTA training set. Using these educational tools, 23 raters from 14 different centers reached an almost perfect agreement (κ 0.92) for the rejection of poor-quality OCTA images using the OSCAR-MP criteria. Discussion We propose a 3-step approach for standardized quality control: (1) To define a specific ROI, (2) to assess the occurrence of OCTA artifacts according to the OSCAR-MP criteria, and (3) to evaluate OCTA quality based on the occurrence of different artifacts within the ROI. OSCAR-MP OCTA QC criteria achieved high interrater agreement in an international multicenter study and is a promising QC protocol for application in the context of future clinical trials and studies

    The OSCAR-MP Consensus Criteria for Quality Assessment of Retinal Optical Coherence Tomography Angiography

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    BACKGROUND AND OBJECTIVES: Optical coherence tomography angiography (OCTA) is a noninvasive high-resolution imaging technique for assessing the retinal vasculature and is increasingly used in various ophthalmologic, neuro-ophthalmologic, and neurologic diseases. To date, there are no validated consensus criteria for quality control (QC) of OCTA. Our study aimed to develop criteria for OCTA quality assessment. METHODS: To establish criteria through (1) extensive literature review on OCTA artifacts and image quality to generate standardized and easy-to-apply OCTA QC criteria, (2) application of OCTA QC criteria to evaluate interrater agreement, (3) identification of reasons for interrater disagreement, revision of OCTA QC criteria, development of OCTA QC scoring guide and training set, and (4) validation of QC criteria in an international, interdisciplinary multicenter study. RESULTS: We identified 7 major aspects that affect OCTA quality: (O) obvious problems, (S) signal strength, (C) centration, (A) algorithm failure, (R) retinal pathology, (M) motion artifacts, and (P) projection artifacts. Seven independent raters applied the OSCAR-MP criteria to a set of 40 OCTA scans from people with MS, Sjogren syndrome, and uveitis and healthy individuals. The interrater kappa was substantial (κ 0.67). Projection artifacts were the main reason for interrater disagreement. Because artifacts can affect only parts of OCTA images, we agreed that prior definition of a specific region of interest (ROI) is crucial for subsequent OCTA quality assessment. To enhance artifact recognition and interrater agreement on reduced image quality, we designed a scoring guide and OCTA training set. Using these educational tools, 23 raters from 14 different centers reached an almost perfect agreement (κ 0.92) for the rejection of poor-quality OCTA images using the OSCAR-MP criteria. DISCUSSION: We propose a 3-step approach for standardized quality control: (1) To define a specific ROI, (2) to assess the occurrence of OCTA artifacts according to the OSCAR-MP criteria, and (3) to evaluate OCTA quality based on the occurrence of different artifacts within the ROI. OSCAR-MP OCTA QC criteria achieved high interrater agreement in an international multicenter study and is a promising QC protocol for application in the context of future clinical trials and studies

    Tracking the evolutionary history of Cortinarius species in section Calochroi, with transoceanic disjunct distributions

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    <p>Abstract</p> <p>Background</p> <p><it>Cortinarius </it>species in section <it>Calochroi </it>display local, clinal and circumboreal patterns of distribution across the Northern Hemisphere where these ectomycorrhizal fungi occur with host trees throughout their geographical range within a continent, or have disjunct intercontinental distributions, the origins of which are not understood. We inferred evolutionary histories of four species, 1) <it>C</it>. <it>arcuatorum</it>, 2) <it>C. aureofulvus</it>, 3) <it>C</it>. <it>elegantior </it>and 4) <it>C. napus</it>, from populations distributed throughout the Old World, and portions of the New World (Central- and North America) based on genetic variation of 154 haplotype internal transcribed spacer (ITS) sequences from 83 population samples. By describing the population structure of these species across their geographical distribution, we attempt to identify their historical migration and patterns of diversification.</p> <p>Results</p> <p>Models of population structure from nested clade, demographic and coalescent-based analyses revealed genetically differentiated and geographically structured haplotypes in <it>C</it>. <it>arcuatorum </it>and <it>C</it>. <it>elegantior</it>, while <it>C</it>. <it>aureofulvus </it>showed considerably less population structure and <it>C. napus </it>lacked sufficient genetic differentiation to resolve any population structure. Disjunct populations within <it>C</it>. <it>arcuatorum, C. aureofulvus </it>and <it>C</it>. <it>elegantior </it>show little or no morphological differentiation, whereas in <it>C. napus </it>there is a high level of homoplasy and phenotypic plasticity for veil and lamellae colour. The ITS sequences of the type specimens of <it>C. albobrunnoides </it>and <it>C. albobrunnoides </it>var. <it>violaceovelatus </it>were identical to one another and are treated as one species with a wider range of geographic distribution under <it>C. napus</it>.</p> <p>Conclusions</p> <p>Our results indicate that each of the <it>Calochroi </it>species has undergone a relatively independent evolutionary history, hypothesised as follows: 1) a widely distributed ancestral population of <it>C</it>. <it>arcuatorum </it>diverged into distinctive sympatric populations in the New World; 2) two divergent lineages in <it>C</it>. <it>elegantior </it>gave rise to the New World and Old World haplotypes, respectively; and 3) the low levels of genetic divergence within <it>C</it>. <it>aureofulvus </it>and <it>C</it>. <it>napus </it>may be the result of more recent demographic population expansions. The scenario of migration via the Bering Land Bridge provides the most probable explanation for contemporaneous disjunct geographic distributions of these species, but it does not offer an explanation for the low degree of genetic divergence between populations of <it>C. aureofulvus </it>and <it>C. napus</it>. Our findings are mostly consistent with the designation of New World allopatric populations as separate species from the European counterpart species <it>C. arcuatorum </it>and <it>C. elegantior</it>. We propose the synonymy of <it>C. albobrunnoides</it>, <it>C. albobrunnoides </it>var. <it>violaceovelatus </it>and <it>C. subpurpureophyllus </it>var. <it>sulphureovelatus </it>with <it>C. napus</it>. The results also reinforce previous observations that linked <it>C. arcuatorum </it>and <it>C. aureofulvus </it>displaying distributions in parts of North America and Europe. Interpretations of the population structure of these fungi suggest that host tree history has heavily influenced their modern distributions; however, the complex issues related to co-migration of these fungi with their tree hosts remain unclear at this time.</p

    Multidimensional Characterization and Differentiation of Neurons in the Anteroventral Cochlear Nucleus

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    Multiple parallel auditory pathways ascend from the cochlear nucleus. It is generally accepted that the origin of these pathways are distinct groups of neurons differing in their anatomical and physiological properties. In extracellular in vivo recordings these neurons are typically classified on the basis of their peri-stimulus time histogram. In the present study we reconsider the question of classification of neurons in the anteroventral cochlear nucleus (AVCN) by taking a wider range of response properties into account. The study aims at a better understanding of the AVCN's functional organization and its significance as the source of different ascending auditory pathways. The analyses were based on 223 neurons recorded in the AVCN of the Mongolian gerbil. The range of analysed parameters encompassed spontaneous activity, frequency coding, sound level coding, as well as temporal coding. In order to categorize the unit sample without any presumptions as to the relevance of certain response parameters, hierarchical cluster analysis and additional principal component analysis were employed which both allow a classification on the basis of a multitude of parameters simultaneously. Even with the presently considered wider range of parameters, high number of neurons and more advanced analytical methods, no clear boundaries emerged which would separate the neurons based on their physiology. At the current resolution of the analysis, we therefore conclude that the AVCN units more likely constitute a multi-dimensional continuum with different physiological characteristics manifested at different poles. However, more complex stimuli could be useful to uncover physiological differences in future studies

    In vivo hippocampal subfield volumes in bipolar disorder—A mega-analysis from The Enhancing Neuro Imaging Genetics through Meta-Analysis Bipolar Disorder Working Group

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    The hippocampus consists of anatomically and functionally distinct subfields that may be differentially involved in the pathophysiology of bipolar disorder (BD). Here we, the Enhancing NeuroImaging Genetics through Meta‐Analysis Bipolar Disorder workinggroup, study hippocampal subfield volumetry in BD. T1‐weighted magnetic resonance imaging scans from 4,698 individuals (BD = 1,472, healthy controls [HC] = 3,226) from 23 sites worldwide were processed with FreeSurfer. We used linear mixed‐effects models and mega‐analysis to investigate differences in hippocampal subfield volumes between BD and HC, followed by analyses of clinical characteristics and medication use. BD showed significantly smaller volumes of the whole hippocampus (Cohen's d = −0.20), cornu ammonis (CA)1 (d = −0.18), CA2/3 (d = −0.11), CA4 (d = −0.19), molecular layer (d = −0.21), granule cell layer of dentate gyrus (d = −0.21), hippocampal tail (d = −0.10), subiculum (d = −0.15), presubiculum (d = −0.18), and hippocampal amygdala transition area (d = −0.17) compared to HC. Lithium users did not show volume differences compared to HC, while non‐users did. Antipsychotics or antiepileptic use was associated with smaller volumes. In this largest study of hippocampal subfields in BD to date, we show widespread reductions in nine of 12 subfields studied. The associations were modulated by medication use and specifically the lack of differences between lithium users and HC supports a possible protective role of lithium in BD

    Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex

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    The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders

    Delirium in nursing homes: prevalence study

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    The prevalence study is part of the project "Delirium in nursing homes" (DeliNH). In the prevalence study, the aim is to assess the Delirium prevalence of nursing home residents in Germany

    Untersuchungen zum Vorkommen von Mycotoxinen bei Auftreten der Rußfleckenkrankheit an Apfelfrüchten

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    In den Anbaugebieten der gemäßigten Klimazonen ist die Rußfleckenkrankheit eine häufig auftretende Pilzkrankheit beim Apfel (Malus xdomestica Borkh.). Die Gefahr des Befalls mit Rußfleckenerregern steigt durch einen verminderten Einsatz von Fungiziden sowie mit dem vermehrten Anbau schorfresistenter Apfelsorten, die ebenfalls in der Regel wenigen oder keinen Fungizidspritzungen ausgesetzt sind. Dieses trifft vor allem im ökologischen Anbau zu. In den USA wurden 1993 in einer Flüssigkultur eines Peltaster fructicola-Isolates, einem der pilzlichen Erreger der Rußfleckenkrankheit, die Mycotoxine Trichothecolon und Trichothecolon-Acetat gefunden. Daher wurden die in Deutschland als Erreger der Rußfleckenkrankheit geltenden Pilze auf ihre Fähigkeit untersucht, Mycotoxine der Gruppe der Trichothecene zu bilden. Die bisherigen Untersuchungen zeigen, dass weder in Flüssigkulturen der einzelnen Erreger der Rußfleckenkrankheit, noch in Schalen befallener Apfelfrüchte, noch in Apfelsäften die Trichothecene Trichothecin und Trichothecolon vorkommen. Auch die zusätzlich analysierten Toxine Nivalenol, Deoxynivalenol, Diacetoxyscirpenol und T-2 Toxin wurden nicht gefunden. Aufgrund der bisher vorliegenden Ergebnisse liegen keinerlei Hinweise vor, dass deutsche Apfelfrüchte oder Apfelprodukte mit Mycotoxinen aus der Gruppe der Trichothecene kontaminiert sind. Dennoch sind weitergehende Untersuchungen erforderlich, da es Hinweise gibt, dass viele Pilze nur unter bestimmten Stresssituationen Mycotoxine produzieren. Hinzu kommt, dass die dem Pilz zur Verfügung stehenden Nährstoffe, insbesondere deren Stickstoff- und Kohlenstoff-Gehalte, einen wesentlichen Einfluss auf die Mycotoxinbildung zu haben scheinen. Des Weiteren ist zu untersuchen, inwiefern eine Mycotoxinproduktion von der jeweiligen, klimatisch unterschiedlichen Herkunft der Erreger abhängig ist. Auch wäre zu klären, ob die in Betracht gezogenen Erreger der Rußfleckenkrankheit über die notwendigen Gene für eine Mycotoxin-Synthese verfügen. Hier besteht nach wie vor großer Forschungsbedarf
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