45 research outputs found
Nicht-invasive Evaluation der Lebermanifestation der Zystischen Fibrose (CFLD) bei Erwachsenen mit Acoustic Radiation Force Impulse (ARFI) - Imaging, Transienter Elastographie (TE) und verschiedenen Fibrosescores
No full textIn der vorliegenden medizinischen Promotionsschrift werden verschiedene nicht-invasive Untersuchungsverfahren bei erwachsenen Patienten mit Zystischer Fibrose (CF) zur Detektion einer Leberbeteiligung (CFLD) evaluiert. Das diagnostische Standard-verfahren bei vielen Hepatopathien, die Leberbiopsie, ist auf Grund der fokalen Manifestation der CFLD und der häufigen pulmonalen Begleiterkrankung bei CF nicht Bestandteil der Routinediagnostik. CF-
Patienten werden daher im Rahmen der vorliegenden Studie mittels konventionellen Ultraschalls, Acoustic Radiation Force Impulse (ARFI) - Imagings, Transienter Elastographie (TE) und verschiedener Fibrosescores untersucht. Ferner wird die Eignung der elastographischen Methoden als Verlaufsparameter bei einem Teil der Studienkohorte evaluiert. Ziel ist die Bewertung des diagnostischen Nutzens der angewandten Untersuchungsmethoden bezüglich der Differenzierung zwischen CF-Patienten ohne Leberbeteiligung, CFLD und CFLD-induzierter Zirrhose. Lebergesunde Probanden und
Patienten mit ethyltoxischer Leberzirrhose dienen als Kontrollgruppen.
Die Ergebnisse dieser wissenschaftlichen Arbeit zeigen, dass die elastographische Untersuchung der Leber bei erwachsenen CF- Patienten, als nicht-invasives Verfahren im Rahmen der Routinediagnostik zur Detektion einer CFLD-induzierten Zirrhose, ergänzend genutzt werden kann. Für die Beurteilung des klinischen Nutzens als Verlaufsparameter sind weitere Studien notwendig.:A Abkürzungsverzeichnis
B Promotionsschrift
1 Bibliographische Beschreibung
2 Einführung
2.1 Zystische Fibrose
2.2 Cystic Fibrosis related Liver Disease – CFLD
2.3 CFLD-Diagnostik
2.3.1 Leberhistologie
2.3.2 Konventioneller Ultraschall
2.3.3 Neue diagnostische Ansätze
2.3.3.1 Elastographieverfahren
2.3.3.1.1 Transiente Elastographie (TE)
2.3.3.1.2 Acoustic Radiation Force Impulse (ARFI) – Imaging
2.3.3.2 Serummarker und Fibrosescores
2.3.3.2.1 AST-to-platelet-ratio-index (APRI) -Score
2.3.3.2.2 Forns-Score
2.4 Rationale der vorliegenden Studie
3 Eigener Beitrag zu der Publikation
4 Publikationen
4.1 Publikation 1
4.1.1 Skizzierung der 1. Publikation
4.1.2 Originalpublikation 1
4.2 Publikation 2
4.2.1 Skizzierung der 2. Publikation
4.2.2 Originalpublikation 2
5 Zusammenfassung der Arbeit
5.1 Grundlagen und Durchführung
5.2 Ergebnisse und Auswertung
C Literaturverzeichnis
D Erklärung über die eigenständige Abfassung der Arbeit
E Curriculum vitae
F Publikationen
G Danksagun
Specialists and generalists fulfil important and complementary functional roles in ecological processes
No full textSpecies differ in their resource use and their interactions with other species and, consequently, they fulfil different functional roles in ecological processes. Species with specialized functional roles (specialists) are considered important for communities because they often interact with species with which few other species interact, thereby contributing complementary functional roles to ecological processes. However, the contribution of specialists could be low if they only interact with a small range of interaction partners. In contrast, species with unspecialized functional roles (generalists) often do not fulfil complementary roles but their contribution to ecological processes could be high because they interact with a large range of species. To investigate the importance of the functional roles of specialists versus generalists, we tested the relationship between species' degree of specialization and their contribution to functional-role diversity for frugivorous birds in Andean seed-dispersal networks. We used two measures for the specialization of birds—one based on the size, and one based on the position of their interaction niche—and measured their effect on the birds' contribution to functional-role diversity and their functional complementarity, a measure of how much a species' functional role is complementary to those of the other species. In all networks, there were similar log-normal distributions of species' contributions to functional-role diversity and functional complementarity. Contribution to functional-role diversity and functional complementarity increased with both increasing niche-position specialization and increasing niche size, indicating that the composition of functional roles in the networks was determined by an interplay between specialization and generalization. There was a negative interaction between niche-position specialization and niche size in both models, which showed that the positive effect of niche-position specialization on functional-role diversity and functional complementarity was stronger for species with a small niche size, and vice versa. Our results show that there is a continuum from specialized to generalized functional roles in species communities, and that both specialists and generalists fulfil important functional roles in ecological processes. Combining interaction networks with functional traits, as exemplified in this study, provides insight into the importance of an interplay of redundancy and complementarity in species' functional roles for ecosystem functioning. A free Plain-Language Summary can be found within the Supporting Information of this article.Fil: Dehling, Matthias. University of Canterbury; Nueva Zelanda. Eidgenössische Forschungsanstalt Für Wald, Schnee Und Landschaft Wsl; SuizaFil: Bender, Irene Maria Antoinetta. Senckenberg Biodiversität Und Klima Forschungszentrum; Alemania. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Blendinger, Pedro Gerardo. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Böhning Gaese, Katrin. Goethe Universitat Frankfurt; Alemania. Senckenberg Biodiversität Und Klima Forschungszentrum; AlemaniaFil: Muñoz, Marcia C.. Universidad de la Salle, Bogota; ColombiaFil: Neuschulz, Eike L.. Senckenberg Biodiversität Und Klima Forschungszentrum; AlemaniaFil: Quitián, Marta. Tokyo Metropolitan University; JapónFil: Saavedra, Francisco. Universidad Mayor de San Andrés; BoliviaFil: Santillán, Vinicio. Universidad Católica de Cuenca; EcuadorFil: Schleuning, Matthias. Senckenberg Biodiversität Und Klima Forschungszentrum; AlemaniaFil: Stouffer, Daniel B.. University of Canterbury; Nueva Zeland
Reaktionsmuster des Oberkiefers von Säuglingen mit einseitigen Lippen-Kiefer-Gaumen-Spalten nach 3-D-Modellanalyse
No full textMap of the study area and schematic diagram showing the design of the survey of plant diversity and forest characteristics.
No full text<p>(A) The study area in South Africa and the locations of the thirty study plots used for tree surveys within and in the surroundings of the (B) Vernon Crookes and (C) Oribi Gorge Nature Reserves. The main habitat and land-use types are depicted in different gray intensities. Symbols in (B) and (C) refer to the five types of forest modification (NFor = large natural scarp forests; NFra = natural scarp forest fragments; PFra = scarp forest fragments within eucalyptus plantations; AFra = scarp forest fragments within sugarcane plantations; SFor = secondary forests). The schematic diagram in (D) shows the study design used to map adult trees, saplings, and seedlings as well as the environmental characteristics within subplots of the 500-m<sup>2</sup> study plots. Note that only 27 out of the 30 study plots were investigated for bird diversity, but the null model analysis of the phylogenetic diversity of plants was based on data from all 30 study plots. Map modified after [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118722#pone.0118722.ref033" target="_blank">33</a>].</p
Spatial and temporal fluctuations in bird communities along a forest-farmland gradient in western Kenya
No full textThe impacts of human activities, notably the conversion of tropical forests into farmland habitat, has profound impacts on biological diversity and ecosystem functions (Millennium Ecosystem Assessment 2005). It is widely debated to what extent human modified landscapes can maintain tropical biodiversity and their ecosystem functionality (e.g. Waltert et al. 2004, Sekercioglu et al. 2007). In this thesis, I have used a huge and temporarily replicated dataset to assess the value of different habitat types differing in land-use intensities for bird communities in tropical East Africa. I investigated bird abundance and species richness along a forest-farmland habitat gradient and assessed spatial and temporal fluctuations of bird assemblages and their food resources.
I could show that forest and farmland habitats harbor distinct bird communities. Moreover, the protection of natural forests merits the highest priority for conserving the high diversity of forest-dependent bird species. My study, however, also shows that farmland habitats in the proximity of natural forest can support a high bird diversity. High bird diversity in tropical farmlands depends on a high structural complexity, such as in small-scale subsistence farmlands. From my findings, I conclude that the conversion of forest to farmland leads to substantial losses in bird diversity, in particular in specialized feeding guilds such as insectivores, while the conversion of structurally heterogeneous subsistence farmlands to sugarcane plantation causes erosion of bird diversity in agricultural ecosystems. Both findings are important for conservation planning in times when tropical forests and agroecosystems are under constantly high pressure due to increasing human population numbers and global demands for biofuel crops (Gibbs et al. 2008). From an ecosystem function perspective, my study demonstrates the potential of agroecosystems in supporting important ecosystem functions, such as seed dispersal by frugivorous birds and pest control by insectivorous birds. I could show that bird abundances in both frugivorous and insectivorous guilds were strongly predicted by their respective food resources, implying that seasonal shifts in fruit and invertebrate abundance at Kakamega forest and surrounding farmlands affect community dynamics and appear to influence local movement patterns of birds. The most interesting finding of this study was that feeding guilds responded idiosyncratically to resource fluctuations. Frugivore richness fluctuated asynchronously in forest and farmland habitats, suggesting foraging movements and fruit tracking across habitat borders. In contrast, I found that insectivores fluctuated synchronously in the two habitat types, suggesting a lack of inter-habitat movements. I therefore predict that insectivorous bird communities in this forest-farmland landscape may be more susceptible to the combined effects of land-use and climate change, due to their narrow habitat niche and limited capacity to track their resources.
The fact that a number of bird species regularly moved across the landscape mosaic in my study system implies that birds are able to provide long-distance seed dispersal across habitat borders. Thus, birds may enhance forest regeneration in human-modified landscapes, such as those in most parts of tropical Africa, given that forest remnants are protected within an agricultural habitat matrix. In order to effectively conserve tropical biodiversity within forest-farmland mosaics, this study advocates for conservation strategies that go beyond forest protection and explicitly integrate farmlands into forest management plans and policies. This should emphasize the retention of keystone habitat elements within tropical farmland landscapes, such as indigenous trees, forest galleries and hedgerows, whose presence enhance species diversity. Such grassroot-level approaches can be operationalized for instance through providing incentives to farmers to maintain their traditional subsistence land-use practices and through community-based livelihood projects aiming at enhancing local habitat heterogeneity and inter-habitat connectivity
Effects of forest disturbance, forest loss, and spatial trends (easting and northing of the study plots) on the taxonomic and phylogenetic α-diversity of species groups.
No full text<p>Separate models were calculated for (a) plants and (b) birds. The coefficients from model averaging of equivalently likely models (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118722#sec002" target="_blank">Methods</a>) are shown. Akaike weights yield information on the relative importance of multiple predictors per model. Statistically significant predictors (p < 0.050) are shown in boldface type. With the exception of life stage, all predictors were Z-transformed to facilitate comparisons of effect sizes.</p><p><sup>a</sup> Note that these are t-values from the single “best” multiple linear regression model; no model averaging was necessary and Z-values are reported for averaged models only.</p><p>Effects of forest disturbance, forest loss, and spatial trends (easting and northing of the study plots) on the taxonomic and phylogenetic α-diversity of species groups.</p
The tin sulfates Sn(SO4)2 and Sn2(SO4)3: crystal structures, optical and thermal properties
No full textFunding: H. A. H. and P. N. thank the Deutsche Forschungsgemeinschaft (DFG) for financial support under the project HO 4503/5-1.We report the crystal structures of two tin(iv) sulfate polymorphs Sn(SO4)2-I (P21/c (no. 14), a = 504.34(3), b = 1065.43(6), c = 1065.47(6) pm, β = 91.991(2)°, 4617 independent reflections, 104 refined parameters, wR2 = 0.096) and Sn(SO4)2-II (P21/n (no. 14), a = 753.90(3), b = 802.39(3), c = 914.47(3) pm, β = 92.496(2)°, 3970 independent reflections, 101 refined parameters, wR2 = 0.033). Moreover, the first heterovalent tin sulfate Sn2(SO4)3 is reported which adopts space group P̄ (no. 2) (a = 483.78(9), b = 809.9(2), c = 1210.7(2) pm, α = 89.007(7)°, β = 86.381(7)°, γ = 73.344(7)°, 1602 independent reflections, 152 refined parameters, wR2 = 0.059). Finally, SnSO4 – the only tin sulfate with known crystal structure – was revised and information complemented. The optical and thermal properties of all tin sulfates are investigated by FTIR, UV-vis, luminescence and 119Sn Mössbauer spectroscopy as well as thermogravimetry and compared.Peer reviewe
Spatio-temporal mRNA tracking in the early zebrafish embryo
No full textEarly stages of embryogenesis are known to depend on subcellular localization and transport of maternal mRNA, but systematic analyses have been hindered by a lack of methods for tracking of RNA. Here the authors combine spatially-resolved transcriptomics and single-cell RNA labeling to perform a spatio-temporal analysis of the transcriptome during early zebrafish development, revealing insights into this process
Spatio-temporal fluctuations of a) bird abundance, b) evenness and c) species richness across three elevations (1000, 2000, 3000 m) and in the most humid (white) and least humid (grey) season.
No full textEach box depicts the median, and 25th and 75th percentiles of bird records of six plots replicated four times within the respective season. Whiskers indicate the normal data range, circles represent outliers.</p
