Reassessment of the evidence for postcranial skeletal pneumaticity in Triassic archosaurs, and the early evolution of the avian respiratory system.

Uniquely among extant vertebrates, birds possess complex respiratory systems characterised by the combination of small, rigid lungs, extensive pulmonary air sacs that possess diverticula that invade (pneumatise) the postcranial skeleton, unidirectional ventilation of the lungs, and efficient crosscurrent gas exchange. Crocodilians, the only other living archosaurs, also possess unidirectional lung ventilation, but lack true air sacs and postcranial skeletal pneumaticity (PSP). PSP can be used to infer the presence of avian-like pulmonary air sacs in several extinct archosaur clades (non-avian theropod dinosaurs, sauropod dinosaurs and pterosaurs). However, the evolution of respiratory systems in other archosaurs, especially in the lineage leading to crocodilians, is poorly documented. Here, we use µCT-scanning to investigate the vertebral anatomy of Triassic archosaur taxa, from both the avian and crocodilian lineages as well as non-archosaurian diapsid outgroups. Our results confirm previous suggestions that unambiguous evidence of PSP (presence of internal pneumatic cavities linked to the exterior by foramina) is found only in bird-line (ornithodiran) archosaurs. We propose that pulmonary air sacs were present in the common ancestor of Ornithodira and may have been subsequently lost or reduced in some members of the clade (notably in ornithischian dinosaurs). The development of these avian-like respiratory features might have been linked to inferred increases in activity levels among ornithodirans. By contrast, no crocodile-line archosaur (pseudosuchian) exhibits evidence for unambiguous PSP, but many of these taxa possess the complex array of vertebral laminae and fossae that always accompany the presence of air sacs in ornithodirans. These laminae and fossae are likely homologous with those in ornithodirans, which suggests the need for further investigation of the hypothesis that a reduced, or non-invasive, system of pulmonary air sacs may be have been present in these taxa (and secondarily lost in extant crocodilians) and was potentially primitive for Archosauria as a whole

The Senate’s CIA torture report marks a return to democratic accountability that went astray during the Bush era

This week saw the U.S. Senate Intelligence Committee release its report on the CIA’s interrogation practices in the wake of the 9/11 attacks in 2001. David M. Barrett reflects on the report, writing that it has only been through the determination of the Senate Committee and its Chair, Democrat Dianne Feinstein, that the public has been able to learn of the ugly details of the CIA’s practices

Current research in oxidation-resistant carbon-carbon composites at NASA. Langley Research Center

The significant potential of carbon-carbon composites for high-temperature structural applications is well established. For hypersonic vehicle applications, desirable properties include low density, high specific strength and stiffness, low coefficients of thermal expansion, and retention of mechanical properties above 3000 F. A significant problem associated with carbon materials, however, is that they oxidize rapidly in air at temperatures above about 800 F, and therefore must be protected from oxidation. Successful development of effective methods of oxidation protection is key to the eventual utilization of carbon-carbon composites on hypersonic vehicles such as NASP. In this presentation, the basic elements of an oxidation-protection system are described. Results from oxidation-performance evaluations of state-of-the-art ACC-4 type material in simulated airframe vehicle environments (temperature, pressure, and time) conducted at NASA Langley are also presented. NASA Langley has an active research effort to improve the oxidation resistance of carbon-carbon materials for airframe structural and vehicle thermal protection applications. Conversion coating and sealant development research is highlighted

Companion animals and well-being in palliative care nursing: a literature review

Aims and objectives To evaluate and critique current knowledge regarding the role of animals in palliative care. To explore the impact that animals may have on the well-being of individuals and to identify gaps in the evidence base. Background There is recognition that having a companion animal will affect patient experience. Similarly, there has been some previous exploration on the use of specific animal assisted therapies for patients with different healthcare needs. Design A literature review was conducted to identify published and unpublished research about companion animals or animal-assisted therapy in palliative and/or end-of-life care. The primary objective was to explore the impact of animals on well-being at the end of life. Methods A search for literature was carried out using a variety of databases and different combinations of search terms linked to animals in palliative care. Included works were critically appraised and thematically analysed. Results A limited range of literature was identified. From the small number of studies included in the review (n = 4), it appears that there is some evidence of animals (either companion animals or those used specifically to enhance care) having a positive impact on the patient experience. Conclusion This study suggests that animals play a large part in the lives of people receiving palliative care. Using animals to support care may also offer some benefits to the patient experience. However, there appears to be a dearth of high-quality literature in this area. More research is therefore required. Relevance to clinical practice Nurses providing palliative care need to be aware of the part that a companion animal may play in the life of patients. There may also be the opportunity for nurses in some settings to integrate animal therapy into their provision of palliative care