51 research outputs found
Analysis of the FGF gene family provides insights into aquatic adaptation in cetaceans
Cetacean body structure and physiology exhibit dramatic adaptations to their aquatic environment. Fibroblast growth factors (FGFs) are a family of essential factors that regulate animal development and physiology; however, their role in cetacean evolution is not clearly understood. Here, we sequenced the fin whale genome and analysed FGFs from 8 cetaceans. FGF22, a hair follicle-enriched gene, exhibited pseudogenization, indicating that the function of this gene is no longer necessary in cetaceans that have lost most of their body hair. An evolutionary analysis revealed signatures of positive selection for FGF3 and FGF11, genes related to ear and tooth development and hypoxia, respectively. We found a D203G substitution in cetacean FGF9, which was predicted to affect FGF9 homodimerization, suggesting that this gene plays a role in the acquisition of rigid flippers for efficient manoeuvring. Cetaceans utilize low bone density as a buoyancy control mechanism, but the underlying genes are not known. We found that the expression of FGF23, a gene associated with reduced bone density, is greatly increased in the cetacean liver under hypoxic conditions, thus implicating FGF23 in low bone density in cetaceans. Altogether, our results provide novel insights into the roles of FGFs in cetacean adaptation to the aquatic environment.ope
Mysticetes to MiniConference to Manuscripts: Introduction to Thematic Issue on Mysticete Anatomy
Fatal Asphyxiation in Bottlenose Dolphins (Tursiops truncatus) from the Indian River Lagoon
Acoustic allometry and vocal learning in mammals
Acoustic allometry is the study of how animal vocalisations reflect their body size. A key aim of this research is to identify outliers to acoustic allometry principles and pinpoint the evolutionary origins of such outliers. A parallel strand of research investigates species capable of vocal learning, the experience-driven ability to produce novel vocal signals through imitation or modification of existing vocalisations. Modification of vocalizations is a common feature found when studying both acoustic allometry and vocal learning. Yet, these two fields have only been investigated separately to date. Here, we review and connect acoustic allometry and vocal learning across mammalian clades, combining perspectives from bioacoustics, anatomy and evolutionary biology. Based on this, we hypothesize that, as a precursor to vocal learning, some species might have evolved the capacity for volitional vocal modulation via sexual selection for ‘dishonest’ signalling. We provide preliminary support for our hypothesis by showing significant associations between allometric deviation and vocal learning in a dataset of 164 mammals. Our work offers a testable framework for future empirical research linking allometric principles with the evolution of vocal learning
Applying problem-based learning to the teaching of anatomy: the example of Harvard Medical School
Between coordination and regulation: Finding the governance in Internet governance
Following recent theoretical contributions, this article suggests a new approach to finding the governance in Internet governance. Studies on Internet governance rely on contradictory notions of governance. The common understanding of governance as some form of deliberate steering or regulation clashes with equally common definitions of Internet governance as distributed modes of ordering. Drawing on controversies in the broader field of governance and regulation studies, we propose to resolve this conceptual conundrum by grounding governance in mundane activities of coordination. We define governance as reflexive coordination – focusing on those ‘critical moments’, when routine activities become problematic and need to be revised, thus, when regular coordination itself requires coordination. Regulation, in turn, can be understood as targeted public or private interventions aiming to influence the behaviour of others. With this distinction between governance and regulation, we offer a conceptual framework for empirical studies of doing Internet governance
Assessment of the Impact of Renal Impairment on Systemic Exposure of New Molecular Entities: Evaluation of Recent New Drug Applications
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