41 research outputs found

    Kretzoiarctos gen. nov., the Oldest Member of the Giant Panda Clade

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    The phylogenetic position of the giant panda, Ailuropoda melanoleuca (Carnivora: Ursidae: Ailuropodinae), has been one of the most hotly debated topics by mammalian biologists and paleontologists during the last century. Based on molecular data, it is currently recognized as a true ursid, sister-taxon of the remaining extant bears, from which it would have diverged by the Early Miocene. However, from a paleobiogeographic and chronological perspective, the origin of the giant panda lineage has remained elusive due to the scarcity of the available Miocene fossil record. Until recently, the genus Ailurarctos from the Late Miocene of China (ca. 8–7 mya) was recognized as the oldest undoubted member of the Ailuropodinae, suggesting that the panda lineage might have originated from an Ursavus ancestor. The role of the purported ailuropodine Agriarctos, from the Miocene of Europe, in the origins of this clade has been generally dismissed due to the paucity of the available material. Here, we describe a new ailuropodine genus, Kretzoiarctos gen. nov., based on remains from two Middle Miocene (ca. 12–11 Ma) Spanish localities. A cladistic analysis of fossil and extant members of the Ursoidea confirms the inclusion of the new genus into the Ailuropodinae. Moreover, Kretzoiarctos precedes in time the previously-known, Late Miocene members of the giant panda clade from Eurasia (Agriarctos and Ailurarctos). The former can be therefore considered the oldest recorded member of the giant panda lineage, which has significant implications for understanding the origins of this clade from a paleobiogeographic viewpoint

    Monitoring integrity and localization of modified single-stranded RNA oligonucleotides using ultrasensitive fluorescence methods

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    Short single-stranded oligonucleotides represent a class of promising therapeutics with diverse application areas. Antisense oligonucleotides, for example, can interfere with various processes involved in mRNA processing through complementary base pairing. Also RNA interference can be regulated by antagomirs, single-stranded siRNA and single-stranded microRNA mimics. The increased susceptibility to nucleolytic degradation of unpaired RNAs can be counteracted by chemical modification of the sugar phosphate backbone. In order to understand the dynamics of such single-stranded RNAs, we investigated their fate after exposure to cellular environment by several fluorescence spectroscopy techniques. First, we elucidated the degradation of four differently modified, dual-dye labeled short RNA oligonucleotides in HeLa cell extracts by fluorescence correlation spectroscopy, fluorescence cross-correlation spectroscopy and Forster resonance energy transfer. We observed that the integrity of the oligonucleotide sequence correlates with the extent of chemical modifications. Furthermore, the data showed that nucleolytic degradation can only be distinguished from unspecific effects like aggregation, association with cellular proteins, or intramolecular dynamics when considering multiple measurement and analysis approaches. We also investigated the localization and integrity of the four modified oligonucleotides in cultured HeLa cells using fluorescence lifetime imaging microscopy. No intracellular accumulation could be observed for unmodified oligonucleotides, while completely stabilized oligonucleotides showed strong accumulation within HeLa cells with no changes in fluorescence lifetime over 24 h. The integrity and accumulation of partly modified oligonucleotides was in accordance with their extent of modification. In highly fluorescent cells, the oligonucleotides were transported to the nucleus. The lifetime of the RNA in the cells could be explained by a balance between release of the oligonucleotides from endosomes, degradation by RNases and subsequent depletion from the cells

    Mudança organizacional: uma abordagem preliminar

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    Successful programs wanted: exploring the impact of alignment.

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    Alignment between formulation and implementation of business strategy can be important for achieving successful programmes. The authors have explored developing a programme management alignment theory. Statistical testing suggests that interaction between the study model variables was found to be multidimensional, complex and subtle in influence. They conclude that programmes have both deliberate and emergent strategies requiring design and management to be organised as complex adaptive systems. Programme lifecycle phases of design and transition were often illustrated by an unclear and confusing strategic picture at the outset which makes it difficult to control. Learning was established as an underlying challenge. The study model demonstrated continuous alignment as an essential attribute contributing towards successful delivery. This requires programme design and structure to adopt an adaptive posture

    Corporate Foundations in Europe

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    The objective is to give an insight into what we know and what we don't know about the current situation of corporate foundations. While we are able to put the spotlight on several interesting developments in the field, this chapter cannot give a comprehensive overview of corporate foundations in all European foundation sectors. As corporate foundations are predominantly public-benefit foundations and part of the nonprofit sector, it is useful to start with a brief overview of the European foundation sector. This may help to gain a first impression of the sector and possibly allows conclusions about the number and country-specific nature of corporate foundations, at least to give some indication about the environment corporate foundations act in
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