258 research outputs found

    Dunhuang – geneza powstanie i strategiczne znaczenie miasta za czasów cesarza Wudi z dynastii Han

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    Dunhuang – the origins of foundation and the strategic importance of the city during the reign of Emperor Wu of the Han Dynasty): Dunhuang was arguably one of the most important cities on the so-called Silk Road. Its establishment was made possible due to Han emperor Wudi’s war against the nomadic tribes of the Xiongnu, who posed a major threat to the Chinese during the early years of the Han dynasty. The city was established as a strategic military settlement that was part of the regional tuntian system, and its role was to help secure the western borders of the empire. Due to the discovery of potential trading partners in the west during the reign of emperor Wudi, as well as the war which resulted in the vassalization of city states in the Takla Makan desert, Dunhuang became a trading hub from where caravans from the Chinese interior travelled west, which only increased its strategic value. This article will discuss what caused the evolution of Dunhaung from a frontier tuntian settlement into a major trading hub and strategically important city

    Deceptive conservatism of claws : distinct phyletic lineages concealed within Isohypsibioidea (Eutardigrada) revealed by molecular and morphological evidence

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    Isohypsibioidea are most likely the most basally branching evolutionary lineage of eutardigrades. Despite being second largest eutardigrade order, phylogenetic relationships and systematics within this group remain largely unresolved. Broad taxon sampling, especially within one of the most speciose tardigrade genera, Isohypsibius Thulin, 1928, and application of both comparative morphological methods (light contrast and scanning electron microscopy imaging of external morphology and buccal apparatuses) and phylogenetic framework (18S + 28S rRNA sequences) resulted in the most comprehensive study devoted to this order so far. Two new families are erected from the currently recognised family Isohypsibiidae: Doryphoribiidae fam. nov., comprising all aquatic isohypsibioids and some terrestrial isohypsibioid taxa equipped with the ventral lamina; and Halobiotidae fam. nov., secondarily marine eutardigrades with unique adaptations to sea environment. We also split Isohypsibius into four genera to accommodate phylogenetic, morphological and ecological variation within the genus: terrestrial Isohypsibius s.s. (Isohypsibiidae), with smooth or sculptured cuticle but without gibbosities; terrestrial Dianea gen. nov. (Isohypsibiidae), with small and pointy gibbosities; terrestrial Ursulinius gen. nov. (Isohypsibiidae), with large and rounded gibbosities; and aquatic Grevenius gen. nov. (Doryphoribiidae fam. nov.), typically with rough cuticle and claws with branches of very similar heigths. Claw morphology is reviewed and, for the first time, shown to encompass a number of morphotypes that correlate with clades recovered in the molecular analysis. The anatomy of pharynx and cuticle are also shown to be of high value in distinguishing supraspecific taxa in Isohypsibioidea. Taxonomy of all isohypsibioid families and genera is discussed, with special emphasis on the newly erected entities. Finally, a dychotomous diagnostic key to all currently recognised isohypsibioid families and genera is provided

    Evaluating markers in selected genes for association with functional longevity of dairy cattle

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    <p>Abstract</p> <p>Background</p> <p>Longevity expressed as the number of days between birth and death is a trait of great importance for both human and animal populations. In our analysis we use dairy cattle to demonstrate how the association of Single Nucleotide Polymorphisms (SNPs) located within selected genes with longevity can be modeled. Such an approach can be extended to any genotyped population with time to endpoint information available. Our study is focused on selected genes in order to answer the question whether genes, known to be involved into the physiological determination of milk production, also influence individual's survival.</p> <p>Results</p> <p>Generally, the highest risk differences among animals with different genotypes are observed for polymorphisms located within the leptin gene. The polymorphism with a highest effect on functional longevity is LEP-R25C, for which the relative risk of culling for cows with genotype CC is 3.14 times higher than for the heterozygous animals. Apart from LEP-R25C, also FF homozygotes at the LEP-Y7F substitution attribute 3.64 times higher risk of culling than the YY homozygotes and VV homozygotes at LEP-A80V have 1.83 times higher risk of culling than AA homozygotes. Differences in risks between genotypes of polymorphisms within the other genes (the butyrophilin subfamily 1 member A1 gene, BTN1A1; the acyl-CoA:diacylglycerol acyltransferase 1 gene, DGAT1; the leptin receptor gene, LEPR; the ATP-binding cassette sub-family G member 2, ABCG2) are much smaller.</p> <p>Conclusions</p> <p>Our results indicate association between LEP and longevity and are very well supported by results of other studies related to dairy cattle. In view of the growing importance of functional traits in dairy cattle, LEP polymorphisms should be considered as markers supporting selection decisions. Furthermore, since the relationship between both LEP polymorphism and its protein product with longevity in humans is well documented, with our result we were able to demonstrate that livestock with its detailed records of family structure, genetic, and environmental factors as well as extensive trait recording can be a good model organism for research aspects related to humans.</p

    Experimental taxonomy exposes ontogenetic variability and elucidates the taxonomic value of claw configuration in Milnesium Doyère, 1840 (Tardigrada : Eutardigrada : Apochela)

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    In this paper we describe a new apochelan species, Milnesium variefidum sp. nov. from Scotland and provide novel morphological and molecular data for Milnesium berladnicorum Ciobanu et al., 2014. The new species differs from the most similar M. berladnicorum by the presence of developmental dimorphism in claw configuration, absent or weakly developed cuticular bars under claws I-III, a different arrangement of cuticular pseudoplates, and by differences in the sequences of three nuclear DNA fragments: 18S rRNA (p-distance: 0.6%), 28S rRNA (2.0%), ITS-2 (9.3%), and on mitochondrial gene COI (12.4%). Although ontogenetic claw configuration change was suspected to occur in some Milnesium species, we are the first to document it through the combined use of traditional, molecular and experimental methodologies. We discuss the implications of the observed phenomenon for the taxonomy of the genus and propose a new diagnostic key to all Milnesium species described up to the end of 2015. We also review other traits used for species differentiation in the genus and offer recommendations to improve the quality of future descriptions as well as suggest a need for integrative redescriptions of the known species. Finally, we propose to suppress M. dujiangensis and M. tardigradum trispinosum and suggest that M. alpigenum and M. quadrifidum are valid species that require thorough redescriptions

    Ekspresja izoform VEGF i ich receptorów w mięśniakach macicy kobiet

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    Objectives: The aim of the study was to determine the expression of VEGF (vascular endothelial growth factor) isoforms and their receptors in uterine myomas. Material and methods: The study included 40 women with myomas of reproductive age and 40 perimenopausal women (the study group). Myometrial samples (the control group) were taken from 10 women undergoing hysterectomy for ovarian tumors and 10 older women undergoing hysterectomy for uterine prolapse. Results: A significantly increased expression of VEGF-A has been found in myomas, both small and large, in the younger women, which may by a sign of increased angiogenesis and intensive tumor growth. In perimenopausal women, the increase of VEGF expression was observed only in the endothelium and vascular smooth muscle. Conclusion: An important conclusion of this study is that angiogenesis is independent of myoma size, which may suggest intensive tumor growth and the related increased angiogenesis. High expression of VEGF-A and VEGF-R1 receptors in large myomas can probably cause malignant transformation and more extensive growth, regardless of patient age.Cel pracy: Celem pracy było próba określenia ekspresji izoform VEGF (ang. vascular endothelial growth factor) i ich receptorów w mięśniakach macicy. Materiał i Metody: Badania przeprowadzono na 40 chorych z mięśniakami w wieku rozrodczym i 40 chorych z mięśniakami w okresie okołomenopauzalnym. Grupę kontrolną stanowiły próby pobrane od 10 kobiet poddanych histerektomii z powodu guzów jajnika i 10 starszych kobiet poddanych histerektomii po wypadnięciu macicy. Wyniki: Stwierdzono statystycznie wyższą ekspresję VEGF-A w komórkach mięśniaków małych i dużych u kobiet młodych. Może to skazywać na zwiększoną angiogenezę, a co za tym idzie wzmożony wzrost guza. U kobiet w wieku okołomenopauzalnym wzrost ekspresji VEGF stwierdzono jedynie w śródbłonku i mięśniówce naczyń. Wniosek: Ważnym podsumowaniem tej pracy, jest stwierdzenie, że angiogeneza jest niezależna od wielkości mięśniaka. Można zatem wnioskować, że wzmożony wzrost guza związany jest ze zwiększoną angiogenezą. Wysoka ekspresja VEGF-A i receptora VEGF-R1 w mięśniakach dużych, może być powiązana ze wzrostem złośliwości komórek i ich intensywnym rozwojem niezależnie od wieku kobiety.

    Das Berufsfeldpraktikum in pädagogischen Einrichtungen des Elementarbereichs. Ein Modellkonzept für das Studium Sprachliche Grundbildung (Grundschullehramt Deutsch)

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    Der Beitrag skizziert und illustriert ein Konzept für die Professionalisierung von Lehramtsstudierenden im Fach Sprachliche Grundbildung an der Universität Duisburg-Essen, bei dem Studierende sprachliche Heterogenität in der praktischen Arbeit mit Kita-Kindern erleben und zugleich Sprachförderung in Kita und Schule vergleichen und reflektieren lernen. Aufgezeigt wird der Modellcharakter dieses Konzepts als Baustein der Professionalisierung angehender Lehrkräfte. (DIPF/Orig.

    Berufsfeldpraktikum Digital lehren lernen im Fach Deutsch. Fachdidaktische Professionalisierung für individuelle Lernbegleitung im digitalen Raum

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    Die Autor*innen stellen ein an der Universität Duisburg-Essen angesiedeltes außerschulisches Lernbegleitungskonzept in Kooperation mit einer ehrenamtlichen Bildungsinitiative vor, das individuelle, digital vermittelte Unterstützung für Schüler:innen mit Nachhilfe- und Förderbedarf im Fach Deutsch bietet. (DIPF/Orig.
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