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Sharks have a long and rich fossil record that consists predominantly of isolated teeth due to the poorly mineralized cartilaginous skeleton. Tiger sharks (Galeocerdo), which represent apex predators in modern oceans, have a known fossil record extending back into the early Eocene (ca. 56 Ma) and comprise 22 recognized extinct and one extant species to date. However, many of the fossil species remain dubious, resulting in a still unresolved evolutionary history of the tiger shark genus. Here, we present a revision of the fossil record of Galeocerdo by examining the morphological diversity and disparity of teeth in deep time. We use landmark-based geometric morphometrics to quantify tooth shapes and qualitative morphological characters for species discrimination. Employing this combined approach on fossil and extant tiger shark teeth, our results only support six species to represent valid taxa. Furthermore, the disparity analysis revealed that diversity and disparity are not implicitly correlated and that Galeocerdo retained a relatively high dental disparity since the Miocene despite its decrease from four to one species. With this study, we demonstrate that the combined approach of quantitative geometric morphometric techniques and qualitative morphological comparisons on isolated shark teeth provides a useful tool to distinguish between species with highly similar tooth morphologies.
Alveolar echinococcosis is a neglected parasitic zoonosis caused by Echinococcus multilocularis. The pharmacological treatment is based on albendazole (ABZ). However, the low water solubility of the drug produces a limited dissolution rate, with the consequent failure in the treatment of the disease. Solid dispersions are a successful pharmacotechnical strategy to improve the dissolution profile of poorly water-soluble drugs. The aim of this work was to determine the in vivo efficacy of ABZ solid dispersions using poloxamer 407 as a carrier (ABZ:P407 solid dispersions (SDs)) in the murine intraperitoneal infection model for secondary alveolar echinococcosis. In the chemoprophylactic efficacy study, the ABZ suspension, the ABZ:P407 SDs and the physical mixture of ABZ and poloxamer 407 showed a tendency to decrease the development of murine cysts, causing damage to the germinal layer. In the clinical efficacy study, the ABZ:P407 SDs produced a significant decrease in the weight of murine cysts. In addition, the SDs produced extensive damage to the germinal layer. The increase in the efficacy of ABZ could be due to the improvement of water solubility and wettability of the drug due to the surfactant nature of poloxamer 407. In conclusion, this study is the basis for further research. This pharmacotechnical strategy might in the future offer novel treatment alternatives for human alveolar echinococcosis.
In this article we present a study that seeks to explain the nature of, and the mortuary practices behind, the burials containing multiple individuals at the site of El Caño, Panama (part of the “Gran Coclé” archaeological tradition, ca. AD 700–1000). We set out to test our first impression of these burials as products of sumptuous funerals held upon the death of the rulers that included, among other practices, human sacrifice. With this in mind, our research aims to elucidate the status relationships between individuals, the circumstances of their deaths, and the religious and symbolic significance of their burials. The results reveal the presence of an individual of higher status within every tomb, the existence of a pattern with respect to the status of those who accompany that individual, the practice of mortuary treatments typical of sacrificial contexts, toxic substances, an iconography referring to human sacrifice, and the clear intention of using a burial as a representation of social order. Considering all this, we conclude that multiple burials at this site should be interpreted as high status. Our study highlights the practice of human sacrifice in funerary rituals linked to that status.
In international relations, accounts of medieval political authority are divided between those who see a heteronomous patchwork of overlapping authorities and those who claim that the era of the state started in the twelfth century. How can we overcome this divide? I argue that IR's current difficulties in grasping the nature of medieval political authority stem from shortcomings in how the notion of political authority itself has been conceptualized. Thus, rather than starting from a substantive definition of political authority, I focus on contestation over the categorization and authorization of rule, that is, on how authority is produced in historically specific ways as a result of contemporary contestation over what political authority is, who is authorized, and how rulers stand in relation to one another. This reorientation allows us to appreciate how medieval political authority emerged from the competition between four sets of ordering categories: iurisdictio, potestas, lord/vassal, and magistrate. Each one of these four categories understood authority, rulers, and the relation between rulers in different ways. The problem with existing accounts of medieval authority is that they attempt to find the single ordering principle of medieval international relations. In doing so, they not only fail to capture the features of the time but also reinforce a particular approach to political authority that is unhelpful for understanding medieval and modern politics alike.
Data regarding humoral immunity against HPV infection are scarce. Most analyses focus on the identification of viruses on mucous membranes and primarily refer to women of reproductive age. The aim of this work was to estimate the seroprevalence of antibodies against HPV serotypes 6, 11, 16 and 18 among unvaccinated boys living in Mexico City. A cross-sectional study of 257 male students from 48 public primary schools in Mexico City, whose ages fluctuated between 9 and 14 years, was carried out. Immunological status was assessed by applying the competitive Luminex Immunoassay of HPV (cLIA). Among the study population, we initially found that 38.52% (n = 99) of the children tested positive against one or more of the HPV 6, 11, 16 and/or 18 serotypes. The most commonly found serotype was isolated HPV 18 or in combination with other serotypes (22% and 31%, respectively), followed by HPV 6 with frequencies of 4.7% and 11%, respectively; however, lower frequencies were estimated for HPV 16 (2%; 6%) and isolated HPV 11, 4%. If a second set of cut-off points for seropositivity is applied, the overall prevalence for any serotype is reduced to 15.2%. As it appears that a significant sector of the study population has had basal contact with an HPV serotype, we recommend considering the possibility of vaccination against HPV at earlier ages.
Solution-processed metal oxide electronics on flexible substrates can enable applications from military to health care. Due to limited thermal budgets and mismatched coefficients of thermal expansion between oxides and substrates, achieving good performance in solution-processed oxide films remains a challenge. Additionally, the use of traditional photolithographic processes is incompatible with low-cost, high-throughput roll-to-roll processing. Here, we demonstrate solution-deposited oxide thin film transistors (TFTs) on a shape memory polymer substrate, which offers unique control of final device shape and modulus. The key enabling step is the exposure of the precursor film to UV-ozone through a shadow mask to perform patterning and photochemical conversion simultaneously. These TFTs exhibit mobility up to 160 cm2/(V s), subthreshold swing as low as 110 mV/dec, and threshold voltage between −2 and 0 V, while maintaining compatibility with a flexible form factor at processing temperatures below 250 °C.
While the historical turn in IR has produced significant advances in historicising both international relations and the discipline itself, the way in which the Middle Ages have been approached, studied, and referenced even in this historically-informed scholarship unwittingly works to reinforce two myths that these scholars challenge: Eurocentrism and Orientalism. The main goal of this article is to problematise the uses of the medieval that reinforce these narratives by unpacking the linguistic and conceptual constructions that underpinned the interactions between Latin Christendom and rest of the world. In doing so, it makes two closely-connected arguments: first, drawing from the abundant literature on historical sociology and Eurocentrism, it argues that we cannot understand medieval Europe, and particularly European identity-formation, without paying attention to its relations with the non-Christian world. Secondly, and most crucially, it shows that these interactions never rested on the unified idea of an ‘infidel enemy’ that seems to emanate from the IR crusading literature. Rather, an examination of the constructions of Jews and Muslims in canon law shows an extremely nuanced and varied conceptual apparatus that creates several dynamics of Othering – and consequently allows for a variety of ways of relating ranging from toleration and coexistence to conquest.