980 resultados para Comparative History
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Abstract Background How are morphological evolution and developmental changes related? This rather old and intriguing question had a substantial boost after the 70s within the framework of heterochrony (changes in rates or timing of development) and nowadays has the potential to make another major leap forward through the combination of approaches: molecular biology, developmental experimentation, comparative systematic studies, geometric morphometrics and quantitative genetics. Here I take an integrated approach combining life-history comparative analyses, classical and geometric morphometrics applied to ontogenetic series to understand changes in size and shape which happen during the evolution of two New World Monkeys (NWM) sister genera. Results Cebus and Saimiri share the same basic allometric patterns in skull traits, a result robust to sexual and ontogenetic variation. If adults of both genera are compared in the same scale (discounting size differences) most differences are small and not statistically significant. These results are consistent using both approaches, classical and geometric Morphometrics. Cebus is a genus characterized by a number of peramorphic traits (adult-like) while Saimiri is a genus with paedomorphic (child like) traits. Yet, the whole clade Cebinae is characterized by a unique combination of very high pre-natal growth rates and relatively slow post-natal growth rates when compared to the rest of the NWM. Morphologically Cebinae can be considered paedomorphic in relation to the other NWM. Geometric morphometrics allows the precise separation of absolute size, shape variation associated with size (allometry), and shape variation non-associated with size. Interestingly, and despite the fact that they were extracted as independent factors (principal components), evolutionary allometry (those differences in allometric shape associated with intergeneric differences) and ontogenetic allometry (differences in allometric shape associated with ontogenetic variation within genus) are correlated within these two genera. Furthermore, morphological differences produced along these two axes are quite similar. Cebus and Saimiri are aligned along the same evolutionary allometry and have parallel ontogenetic allometry trajectories. Conclusion The evolution of these two Platyrrhini monkeys is basically due to a size differentiation (and consequently to shape changes associated with size). Many life-history changes are correlated or may be the causal agents in such evolution, such as delayed on-set of reproduction in Cebus and larger neonates in Saimiri.
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The distribution pattern of European arctic-alpine disjunct species is of growing interest among biogeographers due to the arising variety of inferred demographic histories. In this thesis I used the co-distributed mayfly Ameletus inopinatus and the stonefly Arcynopteryx compacta as model species to investigate the European Pleistocene and Holocene history of stream-inhabiting arctic-alpine aquatic insects. I used last glacial maximum (LGM) species distribution models (SDM) to derive hypotheses on the glacial survival during the LGM and the recolonization of Fennoscandia: 1) both species potentially survived glacial cycles in periglacial, extra Mediterranean refugia, and 2) postglacial recolonization of Fennoscandia originated from these refugia. I tested these hypotheses using mitochondrial sequence (mtCOI) and species specific microsatellite data. Additionally, I used future SDM to predict the impact of climate change induced range shifts and habitat loss on the overall genetic diversity of the endangered mayfly A. inopinatus.rnI observed old lineages, deep splits, and almost complete lineage sorting of mtCOI sequences between mountain ranges. These results support the hypothesis that both species persisted in multiple periglacial extra-Mediterranean refugia in Central Europe during the LGM. However, the recolonization of Fennoscandia was very different between the two study species. For the mayfly A. inopinatus I found strong differentiation between the Fennoscandian and all other populations in sequence and microsatellite data, indicating that Fennoscandia was recolonized from an extra European refugium. High mtCOI genetic structure within Fennoscandia supports a recolonization of multiple lineages from independent refugia. However, this structure was not apparent in the microsatellite data, consistent with secondary contact without sexual incompability. In contrast, the stonefly A. compacta exhibited low genetic structure and shared mtCOI haplotypes among Fennoscandia and the Black Forest, suggesting a shared Pleistocene refugium in the periglacial tundrabelt. Again, there is incongruence with the microsatellite data, which could be explained with ancestral polymorphism or female-biased dispersal. Future SDM projects major regional habitat loss for the mayfly A. inopinatus, particularly in Central European mountain ranges. By relating these range shifts to my population genetic results, I identified conservation units primarily in Eastern Europe, that if preserved would maintain high levels of the present-day genetic diversity of A. inopinatus and continue to provide long-term suitable habitat under future climate warming scenarios.rnIn this thesis I show that despite similar present day distributions the underlying demographic histories of the study species are vastly different, which might be due to differing dispersal capabilities and niche plasticity. I present genetic, climatic, and ecological data that can be used to prioritize conservation efforts for cold-adapted freshwater insects in light of future climate change. Overall, this thesis provides a next step in filling the knowledge gap regarding molecular studies of the arctic-alpine invertebrate fauna. However, there is continued need to explore the phenomenon of arctic-alpine disjunctions to help understand the processes of range expansion, regression, and lineage diversification in Europe’s high latitude and high altitude biota.
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Der Fokus dieser Dissertation ist die populationsgenetische Analyse der neolithischen Bevölkerungswechsel in den 6.-5. Jahrtausende vor Christus, die im westlichen Karpatenbecken stattfanden. Die Zielsetzung der Studie war, mittels der Analyse von mitochondrialer und Y-chromosomaler aDNA, den Genpool der sechs neolithischen und kupferzeitlichen Populationen zu untersuchen und die daraus resultierenden Ergebnisse mit anderen prähistorischen und modernen genetischen Daten zu vergleichen.rnInsgesamt wurden 323 Individuen aus 32 ungarischen, kroatischen und slowakischen Fundplätzen beprobt und bearbeitet in den archäogenetischen Laboren der Johannes Gutenberg-Universität in Mainz. Die DNA Ergebnisse wurden mit verschiedenen populationsgenetischen Methoden ausgewertet. Vergleichsdaten von prähistorischen und modernen eurasiatischen Populationen wurden dazu gesammelt.rnDie HVS-I Region der mitochondrialen DNA konnten bei 256 Individuen reproduziert und authentifiziert werden (mit einer Erfolgsrate von 85.9%). Die Typisierung der HVS-II Region war in 80 Fällen erfolgreich. Testend alle gut erhaltene Proben, die Y-chromosomale Haplogruppe konnte in 33 männlichen Individuen typisiert werden.rnDie neolithischen, mitochondrialen Haplogruppen deuten auf eine hohe Variabilität des maternalen Genpools hin. Sowohl die mitochondrialen als auch die Y-chromosomalen Daten lassen Rückschlüsse auf eine nah-östliche bzw. südwestasiatische Herkunft der frühen Bauern zu. Die Starčevo- und linearbandkermaischen-Populationen in westlichem Karpatenbecken (letztere abgekürzt als LBKT) und die linearbandkermaischen-Population in Mitteleuropa (LBK) haben so starke genetische Ähnlichkeit, dass die Verbreitung der LBK nach Mitteleuropa mit vorangegangenen Wanderungsereignissen zu erklären ist. Die Transdanubische aDNA Daten zeigen hohe Affinität zu den publizierten prähistorischen aDNA Datensätzen von Mitteleuropa aus den 6.-4. Jahrtausende vor Chr. Die maternal-genetische Variabilität der Starčevo-Population konnte auch innerhalb der nachfolgenden Populationen Transdanubiens festgestellt werden. Nur kleinere Infiltrationen und Immigrationsereignissen konnten während der Vinča-, LBKT-, Sopot- und Balaton-Lasinja-Kultur in Transdanubien identifiziert werden. Zwischen den transdanubischen Regionen konnten mögliche genetische Unterschiede nur in der LBKT und in der Lengyel-Periode beobachtet werden, als sich die nördlichen Gruppen von den südlichen Populationen trennten. rnDie festgestellte Heterogenität der mtDNA in Zusammenhang mit der Y-chromosomalen Homogenität in den Starčevo- und LBK-Populationen, weisen auf patrilokale Residenzregeln und patrilineare Abstammungsregeln in den ersten Bauergemeinschaften hin. rnObwohl die hier präsentierten Daten einen großen Fortschritt in der Forschung von aDNA und Neolithikum des Karpatenbeckens und Mitteleuropas bedeuten, werfen sie auch mehrere Fragen auf, deren Beantwortung durch zukünftige Genomforschungen erbracht werden könnte.
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In my thesis, I use historical and literary analysis to study how the concept of the American Dream was popularized during the Great Depression and how cultural understanding of the term has changed following the 2008 Recession. By comparing popular media, literature, and political documents within a historical framework from the 1930s and after 2008 through the present day, I analyze how the term ¿American Dream¿ has persisted as an element of the United States¿ national ethos. I explore why the language of the American Dream does not appear to carry the same resonance in American society as in the 1930s, even though the post-2008 economic environment is somewhat comparable to conditions created by the Great Depression and associated reform measures. This comparative historical approach in scholarly studies of the American Dream is unique because the two periods have not previously been discussed in relation to one another in order to show transformations in cultural understanding of the Dream. The American Dream, both embodying a dual identity as an aspiration to aspire to and also as a delusional fantasy which can lead to cynicism, is a highly complex idea in lived experience. The concept¿s ambiguous nature allows for individuals to interpret it differently, allowing for the term to remain resilient throughout different periods in United States history. While the meaning of the term has been subject to change, it is grounded upon an idealistic concept of American individualism and hope that through one¿s merit, one will be able to achieve one¿s vision of success. Through interdisciplinary analysis, I show that the American Dream will alter to suit the needs of contemporary society and the term¿s power will continue to endure in society despite evidence of rising cynicism since 2008.
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Fungal endocarditis (FE) is an uncommon disease, and while accounting for only 1.3-6% of all cases of infectious endocarditis, it carries a high mortality risk. Although Candida albicans represents the main etiology of FE, C. parapsilosis is the most common non-albicans species. We report the case of a 32-year-old man with a history of prior intravenous drug (IVD) use hospitalized with endocarditis due to C. parapsilosis and review all 71 additional cases documented in the literature. A retrospective analysis of the 72 C. parapsilosis cases compared to 52 recently reviewed cases of C. albicans endocarditis was conducted to identify organism-specific clinical peculiarities. The most common predisposing factor for C. parapsilosis endocarditis (41/72; 57.4%) involved prosthetic valves followed by IVD use (12/72; 20%). Peripheral embolic and/or hemorrhagic events occurred in 28/64 (43.8%) patients, mostly in cerebral and lower limb territories. Overall mortality was 41.7%. Combined surgical and clinical treatment was associated with a lower mortality. Few patients received the newer antifungal agents, and it would appear that more experience is required for their use in the treatment of C. parapsilosis endocarditis.
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BACKGROUND Limited data exist on the longitudinal crestal bone changes around teeth compared with implants in partially edentulous patients. This study sought to compare the 10-year radiographic crestal bone changes (bone level [BL]) around teeth and implants in periodontally compromised (PCPs) and periodontally healthy (PHPs) patients. METHODS A total of 120 patients were evaluated for the radiographic crestal BL around dental implants and adjacent teeth at time of implant crown insertion and at the 10-year follow-up. Sixty patients had a previous history of periodontitis (PCPs), and the remaining 60 were PHPs. In each category (PCP and PHP), two different implant systems were used. The mean BL change at the implant and at the adjacent tooth at the interproximal area was calculated by subtracting the radiographic crestal BL at the time of crown cementation from the radiographic crestal BL at the 10-year follow-up. RESULTS At 10 years after therapy, the survival rate ranged from 80% to 95% for subgroups for implants, whereas it was 100% for the adjacent teeth. In all eight different patient categories evaluated, teeth demonstrated a significantly more stable radiographic BL compared with adjacent dental implants (teeth BL, 0.44 ± 0.23 mm; implant BL, 2.28 ± 0.72 mm; P <0.05). Radiographic BL changes around teeth seemed not to be influenced by the presence or absence of advanced bone loss (≥3 mm) at the adjacent implants. CONCLUSIONS Natural teeth yielded better long-term results with respect to survival rate and marginal BL changes compared with dental implants. Moreover, these findings also extend to teeth with an initial reduced periodontal attachment level, provided adequate periodontal treatment and maintenance are performed. As a consequence, the decision of tooth extraction attributable to periodontal reasons in favor of a dental implant should be carefully considered in partially edentulous patients.
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This article focuses on the studies and discourses of mostly British scholars of the early colonial period belonging to two schools of thought. It shows how the studies of both schools – European orientalism and utilitarianism – were intricately connected to the political development of the emerging British paramountcy over the South Asian sub-continent, as both were looking for means of establishing and/or strengthening colonial rule. Nevertheless, the debate was not just a continuation of discussions in Europe. Whereas the ideas of the European Enlightenment had some influence, the transformation of the Mughal Empire and especially the idea of a decline of Muslim rule offered ample opportunities for understanding the early history of India either as some sort of “Golden Age,” as the orientalists and their indigenous supporters did, or as something static and degenerate, as the utilitarians did, and from which the population of sub-continent had to be saved by colonial rule and colonial values. Fearing the spread of the ideas of the French Revolution, the first group of British scholars sought to persuade the native elites of South Asia to take the lessons of their past for the future development of their homeland. Just as the classicists back in Europe, these scholars were convinced that large-scale explanations of the past could also teach political and moral lessons for the present although it was important to deal with the distant past in an empirical manner. The utilitarians on the other hand believed that India had to be saved from its own depravity through the English language and Western values, which amounted to nothing less than the modern transformation of the true Classical Age.
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An analysis of print Holocaust denial literature as it compares to internet Holocaust denial, with a focus on how the transition from print literature to the internet has affected Holocaust denial.
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no.64 (1977)
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no.53 (1971)