TY - THES A1 - Derežanin, Lorena T1 - Contribution of structural variation to adaptive evolution of mammalian genomes T1 - Beteiligung der strukturellen Variation zur adaptiven Evolution von Säugetiergenomen N2 - Following the extinction of dinosaurs, the great adaptive radiation of mammals occurred, giving rise to an astonishing ecological and phenotypic diversity of mammalian species. Even closely related species often inhabit vastly different habitats, where they encounter diverse environmental challenges and are exposed to different evolutionary pressures. As a response, mammals evolved various adaptive phenotypes over time, such as morphological, physiological and behavioural ones. Mammalian genomes vary in their content and structure and this variation represents the molecular mechanism for the long-term evolution of phenotypic variation. However, understanding this molecular basis of adaptive phenotypic variation is usually not straightforward. The recent development of sequencing technologies and bioinformatics tools has enabled a better insight into mammalian genomes. Through these advances, it was acknowledged that mammalian genomes differ more, both within and between species, as a consequence of structural variation compared to single-nucleotide differences. Structural variant types investigated in this thesis - such as deletion, duplication, inversion and insertion, represent a change in the structure of the genome, impacting the size, copy number, orientation and content of DNA sequences. Unlike short variants, structural variants can span multiple genes. They can alter gene dosage, and cause notable gene expression differences and subsequently phenotypic differences. Thus, they can lead to a more dramatic effect on the fitness (reproductive success) of individuals, local adaptation of populations and speciation. In this thesis, I investigated and evaluated the potential functional effect of structural variations on the genomes of mustelid species. To detect the genomic regions associated with phenotypic variation I assembled the first reference genome of the tayra (Eira barbara) relying on linked-read sequencing technology to achieve a high level of genome completeness important for reliable structural variant discovery. I then set up a bioinformatics pipeline to conduct a comparative genomic analysis and explore variation between mustelid species living in different environments. I found numerous genes associated with species-specific phenotypes related to diet, body condition and reproduction among others, to be impacted by structural variants. Furthermore, I investigated the effects of artificial selection on structural variants in mice selected for high fertility, increased body mass and high endurance. Through selective breeding of each mouse line, the desired phenotypes have spread within these populations, while maintaining structural variants specific to each line. In comparison to the control line, the litter size has doubled in the fertility lines, individuals in the high body mass lines have become considerably larger, and mice selected for treadmill performance covered substantially more distance. Structural variants were found in higher numbers in these trait-selected lines than in the control line when compared to the mouse reference genome. Moreover, we have found twice as many structural variants spanning protein-coding genes (specific to each line) in trait-selected lines. Several of these variants affect genes associated with selected phenotypic traits. These results imply that structural variation does indeed contribute to the evolution of the selected phenotypes and is heritable. Finally, I suggest a set of critical metrics of genomic data that should be considered for a stringent structural variation analysis as comparative genomic studies strongly rely on the contiguity and completeness of genome assemblies. Because most of the available data used to represent reference genomes of mammalian species is generated using short-read sequencing technologies, we may have incomplete knowledge of genomic features. Therefore, a cautious structural variation analysis is required to minimize the effect of technical constraints. The impact of structural variants on the adaptive evolution of mammalian genomes is slowly gaining more focus but it is still incorporated in only a small number of population studies. In my thesis, I advocate the inclusion of structural variants in studies of genomic diversity for a more comprehensive insight into genomic variation within and between species, and its effect on adaptive evolution. N2 - Nach dem Aussterben der Dinosaurier kam es zu einer großen adaptiven Radiation der Säugetiere, die eine erstaunliche ökologische und phänotypische Vielfalt von Säugetierarten hervorbrachte. Selbst eng verwandte Arten bewohnen oft sehr unterschiedliche Lebensräume, in denen sie verschiedenen Umwelteinflüssen und evolutionärem Druck ausgesetzt sind. Als Reaktion darauf haben Säugetiere im Laufe der Zeit verschiedene adaptive Phänotypen entwickelt, z. B. morphologische, physiologische und verhaltensbezogene. Die Genome von Säugetieren variieren in ihrem Inhalt und ihrer Struktur, und diese Variation stellt den molekularen Mechanismus für die langfristige Evolution der phänotypischen Variation dar. Das Verständnis dieser molekularen Grundlage der adaptiven phänotypischen Variation ist jedoch meist nicht trivial. Die jüngste Entwicklung von Sequenzierungstechnologien und Bioinformatik-Tools hat einen besseren Einblick in die Genome von Säugetieren ermöglicht. Durch diese Fortschritte wurde erkannt, dass sich die Genome von Säugetieren sowohl innerhalb als auch zwischen den Arten stärker durch strukturelle Variationen als durch Unterschiede zwischen einzelnen Nukleotiden unterscheiden. Variantenarten, die in dieser Arbeit untersucht werden - wie Deletion, Duplikation, Inversion und Insertion - stellen eine Veränderung der Genomstruktur dar, die sich auf die Größe, die Kopienzahl, die richtung und den Inhalt der DNA-Sequenzen auswirken. Im Gegensatz zu kurzen Varianten können strukturelle Varianten mehrere Gene umfassen. Sie können die Genkopien verändern und bemerkenswerte Unterschiede in der Genexpression und in der Folge phänotypische Unterschiede hervorrufen. Dadurch können sie dramatischere Auswirkungen auf die Fitness (den Fortpflanzungserfolg) von Individuen, die lokale Anpassung von Populationen und die Artbildung haben. In dieser Arbeit untersuchte und bewertete ich die potenziellen funktionellen Auswirkungen von strukturellen Variationen auf die Genome von Mustelidenarten. Weil für die zuverlässige Entdeckung struktureller Varianten ein hohes Maß an Genomvollständigkeit wichtig ist, habe ich das erste Referenzgenom der Tayra (Eira barbara) mit Hilfe der Linked-Read-Sequenzierungstechnologie zusammengestellt, um die mit der phänotypischen Variation verbundenen Genomregionen zu ermitteln. Anschließend habe ich eine Bioinformatik-Pipeline aufgesetzt, um eine vergleichende Genomanalyse durchzuführen und die Variationen zwischen den in unterschiedlichen Umgebungen lebenden Mustelidenarten zu untersuchen. Ich fand heraus, dass zahlreiche Gene, die mit artspezifischen Phänotypen in Verbindung stehen, durch strukturelle Variationen beeinflusst werden. Diese Phänotypen stehen u.a. in Zusammenhang mit Ernährung, Körperzustand und Fortpflanzung. Darüber hinaus untersuchte ich die Auswirkungen der künstlichen Selektion auf strukturelle Variationen bei Mäusen, die auf hohe Fruchtbarkeit, erhöhte Körpermasse und hohe Ausdauer selektiert wurden. Durch selektive Züchtung jeder Mauslinie haben sich die gewünschten Phänotypen innerhalb dieser Populationen durchgesetzt, wobei die für jede Linie spezifischen strukturellen Variationen erhalten blieben. Im Vergleich zur Kontrolllinie hat sich die Wurfgröße in den Linien selektiert auf Fruchtbarkeit verdoppelt, die Individuen in den Linien mit hoher Körpermasse sind erheblich größer geworden, und die auf Laufbandleistung selektierten Mäuse haben wesentlich mehr Strecke zurückgelegt. Im Vergleich zum Referenzgenom der Maus wurden in diesen nach Merkmalen selektierten Linien mehr strukturelle Variationen gefunden als in der Kontrolllinie. Darüber hinaus fanden wir doppelt so viele strukturelle Variationen, die proteinkodierende Gene überspannen (spezifisch für jede Linie), in nach Merkmalen selektierten Linien. Mehrere dieser Varianten betreffen Gene, die mit ausgewählten phänotypischen Merkmalen in Verbindung stehen. Diese Ergebnisse deuten darauf hin, dass strukturelle Variationen tatsächlich zur Evolution der ausgewählten Phänotypen beiträgt und vererbbar ist. Abschließend schlage ich eine Sammlung von maßgeblichen Metriken für Genomdaten vor, die für eine strenge Analyse der strukturellen Variation berücksichtigt werden sollten, da vergleichende Genomstudien in hohem Maße von der Kontiguität und Vollständigkeit der Genomassemblies abhängen. Weil die meisten der verfügbaren Daten, die verwendet wurden, um Referenzgenome von Säugetierarten zu repräsentieren mit Short-Read-Sequenzierungstechnologien erzeugt wurden, verfügen wir möglicherweise nur über unvollständige Kenntnisse der genomischen Merkmale. Daher ist eine vorsichtige Analyse der strukturellen Variationen erforderlich, um die Auswirkungen technischer Beschränkungen zu minimieren. Der Einfluss struktureller Variationen auf die adaptive Evolution von Säugetiergenomen rückt langsam immer mehr in den Mittelpunkt, wird aber immer noch nur in wenigen Populationsstudien berücksichtigt. In meiner Dissertation befürworte ich die Einbeziehung struktureller Variationen in Studien zur genomischen Diversität, um einen umfassenderen Einblick in die genomische Variation innerhalb und zwischen den Arten und ihre Auswirkungen auf die adaptive Evolution zu erhalten. KW - doctoral thesis KW - evolutionary biology KW - adaptation KW - genomics KW - Adaptation KW - Dissertation KW - Evolutionsbiologie KW - Genomik Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-591443 ER - TY - JOUR A1 - Heidenreich, Anna A1 - Buchner, Martin A1 - Walz, Ariane A1 - Thieken, Annegret T1 - How to deal with heat stress at an open-air event? BT - Exploring visitors’ vulnerability, risk perception, and adaptive behavior with a multimethod approach JF - Weather, climate & society / American Meteorological Society N2 - Heat waves are increasingly common in many countries across the globe, and also in Germany, where this study is set. Heat poses severe health risks, especially for vulnerable groups such as the elderly and children. This case study explores visitors' behavior and perceptions during six weekends in the summer of 2018 at a 6-month open-air horticultural show. Data from a face-to-face survey (n = 306) and behavioral observations ( n = 2750) were examined by using correlation analyses, ANOVA, and multiple regression analyses. Differences in weather perception, risk awareness, adaptive behavior, and activity level were observed between rainy days (maximum daily temperature, 25 degrees C), warmsummer days (25 degrees-30 degrees C), and hot days (>30 degrees C). Respondents reported a high level of heat risk awareness, butmost (90%) were unaware of actual heat warnings. During hot days, more adaptive measures were reported and observed. Older respondents reported taking the highest number of adaptive measures. We observed the highest level of adaptation in children, but they also showed the highest activity level. From our results we discuss how to facilitate individual adaptation to heat stress at open-air events by taking the heterogeneity of visitors into account. To mitigate negative health outcomes for citizens in the future, we argue for tailored risk communication aimed at vulnerable groups.
SIGNIFICANCE STATEMENT: People around the world are facing higher average temperatures. While higher temperatures make open-air events a popular leisure time activity in summer, heat waves are a threat to health and life. Since there is not much research on how visitors of such events perceive different weather conditions-especially hot temperatures-we explored this in our case study in southern Germany at an open-air horticultural show in the summer of 2018. We discovered deficits both in people's awareness of current heat risk and the heat adaptation they carry out themselves. Future research should further investigate risk perception and adaptation behavior of private individuals, whereas event organizers and authorities need to continually focus on risk communication and facilitate individual adaptation of their visitors. KW - Extreme events KW - Adaptation KW - Communications/decision making KW - Emergency KW - preparedness KW - Emergency response KW - Field experiments KW - Societal impacts Y1 - 2021 U6 - https://doi.org/10.1175/WCAS-D-21-0027.1 SN - 1948-8327 SN - 1948-8335 VL - 13 IS - 4 SP - 989 EP - 1002 PB - American Meteorological Soc. CY - Boston ER - TY - JOUR A1 - Pregla, Dorothea A1 - Lissón Hernández, Paula J. A1 - Vasishth, Shravan A1 - Burchert, Frank A1 - Stadie, Nicole T1 - Variability in sentence comprehension in aphasia in German JF - Brain & language : a journal of the neurobiology of language N2 - An important aspect of aphasia is the observation of behavioral variability between and within individual participants. Our study addresses variability in sentence comprehension in German, by testing 21 individuals with aphasia and a control group and involving (a) several constructions (declarative sentences, relative clauses and control structures with an overt pronoun or PRO), (b) three response tasks (object manipulation, sentence-picture matching with/without self-paced listening), and (c) two test phases (to investigate test-retest performance). With this systematic, large-scale study we gained insights into variability in sentence comprehension. We found that the size of syntactic effects varied both in aphasia and in control participants. Whereas variability in control participants led to systematic changes, variability in individuals with aphasia was unsystematic across test phases or response tasks. The persistent occurrence of canonicity and interference effects across response tasks and test phases, however, shows that the performance is systematically influenced by syntactic complexity. KW - Aphasia KW - Sentence Comprehension KW - Variability KW - Test-retest reliability KW - Task demands KW - Canonicity and interference effects KW - Object manipulation KW - Sentence-picture matching KW - Self-paced listening KW - Adaptation Y1 - 2021 U6 - https://doi.org/10.1016/j.bl.2021.105008 SN - 0093-934X SN - 1090-2155 VL - 222 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bubeck, Philip A1 - Thieken, Annegret T1 - What helps people recover from floods? BT - insights from a survey among flood-affected residents in German JF - Regional environmental change N2 - The number of people exposed to natural hazards has grown steadily over recent decades, mainly due to increasing exposure in hazard-prone areas. In the future, climate change could further enhance this trend. Still, empirical and comprehensive insights into individual recovery from natural hazards are largely lacking, hampering efforts to increase societal resilience. Drawing from a sample of 710 residents affected by flooding across Germany in June 2013, we empirically explore a wide range of variables possibly influencing self-reported recovery, including flood-event characteristics, the circumstances of the recovery process, socio-economic characteristics, and psychological factors, using multivariate statistics. We found that the amount of damage and other flood-event characteristics such as inundation depth are less important than socio-economic characteristics (e.g., sex or health status) and psychological factors (e.g., risk aversion and emotions). Our results indicate that uniform recovery efforts focusing on areas that were the most affected in terms of physical damage are insufficient to account for the heterogeneity in individual recovery results. To increase societal resilience, aid and recovery efforts should better address the long-term psychological effects of floods. KW - Floods KW - Resilience KW - Recovery KW - Natural hazards KW - Climate change KW - Adaptation Y1 - 2017 U6 - https://doi.org/10.1007/s10113-017-1200-y SN - 1436-3798 SN - 1436-378X VL - 18 IS - 1 SP - 287 EP - 296 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Hudson, Paul T1 - A comparison of definitions of affordability for flood risk adaption measures BT - a case study of current and future risk-based flood insurance premiums in Europe JF - Mitigation and adaptation strategies for global change : an international journal devoted to scientific, engineering, socio-economic and policy responses to environmental change N2 - Risk-based insurance is a commonly proposed and discussed flood risk adaptation mechanism in policy debates across the world such as in the United Kingdom and the United States of America. However, both risk-based premiums and growing risk pose increasing difficulties for insurance to remain affordable. An empirical concept of affordability is required as the affordability of adaption strategies is an important concern for policymakers, yet such a concept is not often examined. Therefore, a robust metric with a commonly acceptable affordability threshold is required. A robust metric allows for a previously normative concept to be quantified in monetary terms, and in this way, the metric is rendered more suitable for integration into public policy debates. This paper investigates the degree to which risk-based flood insurance premiums are unaffordable in Europe. In addition, this paper compares the outcomes generated by three different definitions of unaffordability in order to investigate the most robust definition. In doing so, the residual income definition was found to be the least sensitive to changes in the threshold. While this paper focuses on Europe, the selected definition can be employed elsewhere in the world and across adaption measures in order to develop a common metric for indicating the potential unaffordability problem. KW - Flood risk KW - Insurance KW - Affordability KW - Climate change KW - Adaptation KW - Public policy Y1 - 2018 U6 - https://doi.org/10.1007/s11027-017-9769-5 SN - 1381-2386 SN - 1573-1596 VL - 23 IS - 7 SP - 1019 EP - 1038 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Unterberger, Christian A1 - Hudson, Paul A1 - Botzen, W. J. Wouter A1 - Schroeer, Katharina A1 - Steininger, Karl W. T1 - Future public sector flood risk and risk sharing arrangements BT - An Assessment for Austria JF - Ecological economics N2 - Climate change, along with socio-economic development, will increase the economic impacts of floods. While the factors that influence flood risk to private property have been extensively studied, the risk that natural disasters pose to public infrastructure and the resulting implications on public sector budgets, have received less attention. We address this gap by developing a two-staged model framework, which first assesses the flood risk to public infrastructure in Austria. Combining exposure and vulnerability information at the building level with inundation maps, we project an increase in riverine flood damage, which progressively burdens public budgets. Second, the risk estimates are integrated into an insurance model, which analyzes three different compensation arrangements in terms of the monetary burden they place on future governments' budgets and the respective volatility of payments. Formalized insurance compensation arrangements offer incentives for risk reduction measures, which lower the burden on public budgets by reducing the vulnerability of buildings that are exposed to flooding. They also significantly reduce the volatility of payments and thereby improve the predictability of flood damage expenditures. These features indicate that more formalized insurance arrangements are an improvement over the purely public compensation arrangement currently in place in Austria. KW - Climate change KW - Adaptation KW - Flood risk KW - Insurance KW - Public sector KW - Risk reduction Y1 - 2018 U6 - https://doi.org/10.1016/j.ecolecon.2018.09.019 SN - 0921-8009 SN - 1873-6106 VL - 156 SP - 153 EP - 163 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hudson, Paul A1 - Botzen, W. J. Wouter A1 - Poussin, Jennifer A1 - Aerts, Jeroen C. J. H. T1 - Impacts of flooding and flood preparedness on subjective well-being BT - a monetisation of the tangible and intangible impacts JF - Journal of Happiness Studies N2 - Flood disasters severely impact human subjective well-being (SWB). Nevertheless, few studies have examined the influence of flood events on individual well-being and how such impacts may be limited by flood protection measures. This study estimates the long term impacts on individual subjective well-being of flood experiences, individual subjective flood risk perceptions, and household flood preparedness decisions. These effects are monetised and placed in context through a comparison with impacts of other adverse events on well-being. We collected data from households in flood-prone areas in France. The results indicate that experiencing a flood has a large negative impact on subjective well-being that is incompletely attenuated over time. Moreover, individuals do not need to be directly affected by floods to suffer SWB losses since subjective well-being is lower for those who expect their flood risk to increase or who have seen a neighbour being flooded. Floodplain inhabitants who prepared for flooding by elevating their home have a higher subjective well-being. A monetisation of the aforementioned well-being impacts shows that a flood requires Euro150,000 in immediate compensation to attenuate SWB losses. The decomposition of the monetised impacts of flood experience into tangible losses and intangible effects on SWB shows that intangible effects are about twice as large as the tangible direct monetary flood losses. Investments in flood protection infrastructure may be under funded if the intangible SWB benefits of flood protection are not taken into account. KW - Flooding KW - Subjective well-being KW - Intangible losses KW - Tangible losses KW - Climate change KW - Adaptation KW - Climate change adaptation Y1 - 2017 U6 - https://doi.org/10.1007/s10902-017-9916-4 SN - 1389-4978 SN - 1573-7780 VL - 20 IS - 2 SP - 665 EP - 682 PB - Springer Science CY - Dordrecht ER - TY - JOUR A1 - Malesza, Marta A1 - Ostaszewski, Paweł A1 - Büchner, Susanne A1 - Kaczmarek, Magdalena C. T1 - The adaptation of the Short Dark Triad personality measure BT - psychometric properties of a German sample JF - Current psychology N2 - This research was designed to adapt and investigate the psychometric properties of the Short Dark Triad measure (Jones and Paulhus Assessment, 21(1), 28-41, 2014) in a German sample within four studies (total N=1463); the measure evaluates three personality dimensions: narcissism, psychopathy, and Machiavellianism. The structure of the instrument was analysed by Confirmatory Factor Analyses procedure. It indicated that the three-factor structure had the best fit to the data. Next, the Short Dark Triad measure was evaluated in terms of construct, convergent and discriminant validity, internal consistency ( .72), and test-retest reliability during a 4-week period ( .73). Concurrent validity of the SD3 was supported by relating its subscales to measures of the Big Five concept, aggression, and self-esteem. We concluded that the Short Dark Triad instrument presented high cross-language replicability. The use of this short inventory in the investigation of the Dark Triad personality model in the German language context is suggested. KW - Short dark triad KW - SD3 KW - Adaptation KW - Reliability KW - Validity Y1 - 2019 U6 - https://doi.org/10.1007/s12144-017-9662-0 SN - 1046-1310 SN - 1936-4733 VL - 38 IS - 3 SP - 855 EP - 864 PB - Springer CY - New York ER - TY - JOUR A1 - Schüffler, Arnulf A1 - Thim, Christof A1 - Haase, Jennifer A1 - Gronau, Norbert A1 - Kluge, Annette T1 - Willentliches Vergessen T1 - Intentional forgetting - precondition for flexibility and adaptivity in a permanent changing world BT - Voraussetzung für Flexibilität und Veränderungsfähigkeit in einer sich permanent verändernden Welt JF - Gruppe. Interaktion. Organisation. Zeitschrift für Angewandte Organisationspsychologie (GIO) N2 - Dieser Beitrag im Journal Gruppe. Interaktion. Organisation. stellt dar, wie willentliches Vergessen die Anpassung an notwendige Veränderungen für Individuen, Gruppen und Organisationen verbessert und wie willentliches Vergessen bewusst und gezielt gestaltet werden kann. Damit Verhalten in Folge einer notwendigen Veränderung angepasst wird, reicht es nicht aus, dass Menschen wissen was zu tun ist, willens und in der Lage sind ihr Verhalten zu verändern. Eine Veränderung gelingt nur dann, wenn nur noch das neue Verhalten zur Anwendung kommt und nicht mehr das Alte, wenn das alte Verhalten vergessen wird. Der notwendige Prozess des willentlichen Vergessens ist durch Entfernen von Hinweisreizen, die die Erinnerung des zu Vergessenden und durch Platzierung von Hinweisreizen, die die Aktivierung des Neuen auslösen, gestaltbar. Der vorliegende Beitrag stellt die förderliche Wirkung von Hinweisreizen auf willentliches Vergessen dar, stellt sie im Rahmen des Berichts einer experimentellen Studie unter Beweis und gibt praktische Implikationen, wie für Individuen, Gruppen und Organisationen willentliches Vergessen gestaltet werden kann. N2 - This paper in the journal Gruppe. Interaktion. Organisation. illustrates how intentional forgetting can improve the adaptation to necessary changes for individuals, groups and organizations, and how intentional forgetting can be consciously and purposefully designed.In order for behavior to be adapted as aresult of necessary change, it is not enough for people to know what to do, to be willing and able to change their behavior. Achange succeeds only if the new behavior is activated and not the old one, if the old behavior is forgotten. The necessary process of intentional forgetting can be designed by removing cues that retrieve memory items to be forgotten and placing cues that trigger the retrieval of the new.This paper presents the beneficial effects of cues on intentional forgetting, proves them in the context of areport of an experimental study and gives practical implications on how to design intentional forgetting for individuals, groups and organizations. KW - Intentional forgetting KW - Retrieval cues KW - Change KW - Adaptation KW - Behavior KW - Willentliches Vergessen KW - Hinweisreize KW - Veränderung KW - Anpassung KW - Verhalten Y1 - 2019 U6 - https://doi.org/10.1007/s11612-019-00466-0 SN - 2366-6145 SN - 2366-6218 VL - 50 IS - 2 SP - 197 EP - 209 PB - Springer CY - Wiesbaden ER - TY - JOUR A1 - Cassel, Michael A1 - Risch, Lucie A1 - Mayer, Frank A1 - Kaplick, Hannes A1 - Engel, Aaron A1 - Kulig, Kornelia A1 - Bashford, Greg T1 - Achilles tendon morphology assessed using image based spatial frequency analysis is altered among healthy elite adolescent athletes compared to recreationally active controls JF - Journal of science and medicine in sport : official journal of Sports Medicine Australia N2 - Objectives: Although expected, tendon adaptations in adolescent elite athletes have been underreported. Morphologically, adaptations may occur by an increase in collagen fiber density and/or organization. These characteristics can be captured using spatial frequency parameters extracted from ultrasound images. This study aims to compare Achilles tendon (AT) morphology among sports-specific cohorts of elite adolescent athletes and to compare these findings to recreationally active controls by use of spatial frequency analysis. Design: Cross-sectional observational study. Method: In total, 334 healthy adolescent athletes from four sport categories (ball, combat, endurance, explosive strength) and 35 healthy controls were included. Longitudinal ultrasound scans were performed at the AT insertion and midportion. Intra-tendinous-morphology was quantified by performing spatial frequency analysis assessing eight parameters at standardized ROls. Increased values in five parameters suggest a higher structural organization, and in two parameters higher fiber density. One parameter represents a quotient combining both organization and fiber density. Results: Among athletes, only ball sport athletes exhibited an increase in one summative parameter at pre-insertion site compared to athletes from other sport categories. When compared to athletes, controls had significantly higher values of four parameters at pre-insertion and three parameters at midportion site reflecting differences in both, fiber organization and density. Conclusions: Intra-tendinous-morphology was similar in all groups of adolescent athletes. Higher values found in non-athletes might suggest higher AT fiber density and organization. It is yet unclear whether the lesser structural organization in young athletes represents initial AT pathology, or a physiological adaptive response at the fiber cross-linking level. (C) 2019 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved. KW - Tendon structure KW - Adaptation KW - Ultrasound KW - Athletic loading KW - Tendinopathy Y1 - 2019 U6 - https://doi.org/10.1016/j.jsams.2019.03.011 SN - 1440-2440 SN - 1878-1861 VL - 22 IS - 8 SP - 882 EP - 886 PB - Elsevier CY - Oxford ER -