279 research outputs found

    Einfluss der Retention auf die Weisheitszahnmineralisation

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    Zusammenfassung: In der zahnĂ€rztlichen Altersdiagnostik ist die radiologische Beurteilung der WeisheitszĂ€hne das wichtigste Kriterium bei der Frage nach der Vollendung des 18.Altersjahres. Als alleiniges Kriterium geben die WeisheitszĂ€hne auch bei abgeschlossenem Wurzelwachstum diesbezĂŒglich keine rechtsgenĂŒgende Sicherheit. In der vorgestellten Arbeit wurde untersucht, ob bei retinierten WeisheitszĂ€hnen im Unterkiefer das Wurzelwachstum verzögert wird und damit die Wahrscheinlichkeit fĂŒr ein vollendetes 18.Lebensjahr steigt. Es konnte mithilfe der logistischen Regression gezeigt werden, dass, verglichen mit den FĂ€llen durchgebrochener dritter Molaren, bei retinierten WeisheitszĂ€hnen mit abgeschlossenem Wurzelwachstum eine Verzögerung von 0,6Jahren bei mĂ€nnlichen und 0,7Jahren bei weiblichen Untersuchten auftritt. Es konnte kein einziger Proband mit retinierten unteren WeisheitszĂ€hnen und abgeschlossenem Wurzelwachstum beidseits identifiziert werden, der jĂŒnger als 18Jahre war. Bei Vorliegen eines retinierten dritten Molaren mit abgeschlossenem Wurzelwachstum nur auf einer Seite konnte ein einzelner Explorand von unter 18Jahren festgestellt werden (17Jahre, 11 Monate!). Fazit: Können bei der zahnĂ€rztlichen Altersdiagnostik 2 retinierte WeisheitszĂ€hne mit abgeschlossenem Wurzelwachstum im Unterkiefer festgestellt werden, darf bei MitteleuropĂ€ern ein Mindestalter von 18Jahren mit an Sicherheit grenzender Wahrscheinlichkeit angenommen werden. Ist ein retinierter Unterkieferweisheitszahn mit abgeschlossenem Wurzelwachstum vorhanden, ist das 18.Lebensjahr mit sehr großer Wahrscheinlichkeit vollende

    Dental age diagnostics by means of radiographical evaluation of the growth stages of lower wisdom teeth

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    The main criterion for dental age estimation in living adolescents and young adults is mineralization of third molars. A total of 1,260 orthopantomograms of 669 female and 591 male subjects aged between 15 and 22years was examined. Of the orthopantomograms, 1,137 were from patients with Swiss citizenship and 123 were from other European countries. The mineralization status of lower third molars was evaluated based on Demirjian's classification of stages. For the statistical assessment of data, logistic regression and mean value testing were used. The findings show that completed growth in wisdom teeth is observable at ages less than 18. Male individuals were approximately 1year ahead of females at stage H, and South East Europeans were approximately 6months ahead of Swiss (Central Europe) at stage H. Mean values led to false conclusions regarding the question of the attained age of 18. Therefore, regression analysis should be used for the statistical assessment of data in dental age diagnostic

    Einfluss der Retention auf die Weisheitszahnmineralisation

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    In dental age diagnostics radiological evaluation of third molars is the most important criterion to establish whether an individual has attained 18 years of age. However, completed root development of third molars as the only criterion is insufficient for an establishment of legal certainty. In the present paper it was investigated whether root development is slowed down in impacted lower third molars and thereby increases the probability that 18 years of age has been attained. By means of logistic regression a delay of 0.6 years in male subjects and 0.7 years in female subjects was shown in impacted third molars with completed root development compared to cases with erupted third molars. There was no case in which an individual with impacted lower third molars with completed root development on both sides was under the age of 18. In the presence of impacted third molars with completed root development on one side only one subject was under 18 years of age (17 years and 11 months!). Conclusion: If two impacted third molars with completed root development in the lower jaw are determined in dental age diagnostics, a minimum age of 18 years in central Europeans can be suspected beyond any reasonable doubt. If one impacted mandibular third molar with completed root development is present it is very likely that 18 years of age have been attained

    Sex ratio distorting microbes exacerbate arthropod extinction risk in variable environments

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    Maternally-inherited sex ratio distorting microbes (SRDMs) are common among arthropod species. Typically, these microbes cause female-biased sex ratios in host broods, either by; killing male offspring, feminising male offspring, or inducing parthenogenesis. As a result, infected populations can experience drastic ecological and evolutionary change. The mechanism by which SRDMs operate is likely to alter their impact on host evolutionary ecology; despite this, the current literature is heavily biased towards a single mechanism of sex ratio distortion, male-killing. Furthermore, amidst the growing concerns surrounding the loss of arthropod diversity, research into the impact of SRDMs on the viability of arthropod populations is generally lacking. In this study, using a theoretical approach, we model the epidemiology of an understudied mechanism of microbially-induced sex ratio distortion—feminisation—to ask an understudied question—how do SRDMs impact extinction risk in a changing environment? We constructed an individual-based model and measured host population extinction risk under various environmental and epidemiological scenarios. We also used our model to identify the precise mechanism modulating extinction. We find that the presence of feminisers increases host population extinction risk, an effect that is exacerbated in highly variable environments. We also identified transmission rate as the dominant epidemiological trait responsible for driving extinction. Finally, our model shows that sex ratio skew is the mechanism driving extinction. We highlight feminisers and, more broadly, SRDMs as important determinants of the resilience of arthropod populations to environmental change

    Foundation and empire : a critique of Hardt and Negri

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    In this article, Thompson complements recent critiques of Hardt and Negri's Empire (see Finn Bowring in Capital and Class, no. 83) using the tools of labour process theory to critique the political economy of Empire, and to note its unfortunate similarities to conventional theories of the knowledge economy

    The cost of promiscuity: sexual transmission of Nosema microsporidian parasites in polyandrous honey bees

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    Multiple mating (and insemination) by females with different males, polyandry, is widespread across animals, due to material and/or genetic benefits for females. It reaches particularly high levels in some social insects, in which queens can produce significantly fitter colonies by being polyandrous. It is therefore a paradox that two thirds of eusocial hymenopteran insects appear to be exclusively monandrous, in spite of the fitness benefits that polyandry could provide. One possible cost of polyandry could be sexually transmitted parasites, but evidence for these in social insects is extremely limited. Here we show that two different species of Nosema microsporidian parasites can transmit sexually in the honey bee Apis mellifera. Honey bee males that are infected by the parasite have Nosema spores in their semen, and queens artificially inseminated with either Nosema spores or the semen of Nosema-infected males became infected by the parasite. The emergent and more virulent N. ceranae achieved much higher rates of infection following insemination than did N. apis. The results provide the first quantitative evidence of a sexually transmitted disease (STD) in social insects, indicating that STDs may represent a potential cost of polyandry in social insects

    Global warming and mass extinctions associated with large igneous province volcanism

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    The coincidence of large igneous province (LIP) eruptions with at least three, if not all of the “Big Five” biotic crises of the Phanerozoic implies that volcanism is a key driver of mass extinctions. Many LIP-induced extinction scenarios invoke global warming, caused primarily (but not exclusively) by greenhouse gases emitted at the site of LIP emplacement and by contact metamorphism of carbon-rich host rocks. Here we explore a) the climate-changing products of volcanism including sulfur dioxide (SO2), carbon dioxide (CO2) and methane (CH4) from eruptions, contact metamorphism, and melting (dissociation) of gas hydrates; b) their deadly effects, including marine anoxia and thermal stress; c) increasingly sophisticated paleotemperature proxies (e.g. ή18O of shell material) through case studies of the best-known LIP-warming-extinction nexi; and d) global warming through the lens of the putative “Anthropocene” extinction

    Promoting Value Practice in Museums Creates Impact

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    This article examines how museological value discussion can offer a tool for museum professionals to engage themselves in the current discourse regarding building sustainable futures. The focus of the article is on collection care and collection development. It describes the latest interview and workshop results regarding museum values in the field of collection development among Finnish museum professionals and students. In addition, it emphasizes the integration of theoretical knowledge and its practical application. Promoting and creating opportunities for value discussion among museum professionals increases the ability of these professionals to further engage in such value-related discourse with various stakeholders. Eventually, the benefits of this kind of value-based discussions are to be seen in the more coherent and focused ones regarding museological values between and among various parties, be they museum professionals, politicians, students or museum visitors. The initial idea for the interviews, and subsequently the workshops as well, emerged from a collection development survey conducted in 2012 among Finnish art museums, which was published in 2016 by the author. Based on the material analyzed at that time, it became clear that the issue of active values in Finnish museums would need further study.Peer reviewe
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