Toothed pterosaurs from the Santana Formation (Cretaceous; Aptian-Albian) of northeastern Brazil. A reappraisal on the basis of newly described material

The increasing numbers of pterosaur finds from Brazil obviously increased our knowledge, but through the years, taxonomy has become less clear as one would expect. Various reasons can be given for this. One is that important morphological features have not been incorporated in the discussion whereas others are, but have questionable taxonomic value. Also, sometimes unstated assumptions play an important role on which pterosaurs have been re-classified. It is understandable that one seeks a connection with the pterosaurs from the Cambridge Greensands in England, but this has had a negative impact on the systematics: the fossils from the Cambridge Greensands themselves have been subject to fierce debates and much confusion ever since their first discovery in the latter half of the 19th century. The present work presents a reappraisal of four closely related taxa with teeth (Anhanguera, Brasileodactylus, Coloborhynchus en Criorhynchus) by means of the study of unpublished and published material in the major collections all around the world, concentrating on cranial parts. In chapter 2, a largely complete skeleton of Coloborhynchus is described. The specimen has been classified as new species. Chapter 3 presents various post-cranial elements, on the basis of which it is concluded that interspecific differences in the post-cranial skeleton are so small that an evaluation is necessary. More important for the present work, however, is the description of the mandible of Criorhynchus, which confirms the strong deviating dentition pattern relative to the other taxa. Chapter 4 presents one of the most complete mandibles of Anhanguera. The study of this specimen resulted among others in the discovery of an important diagnostic morphological feature of the mandible. The next chapter (chapter 5) is a preliminary description of a largely unprepared skull and wing of a fossil in the collection of the AMNH, New York. The specimen is tentatively classified as Brasileodactylus mainly because of the crestless jaws (currently, the fossil is completely prepared and under study). In chapter 6, an almost complete mandible of Brasileodactylus is described. Furthermore, post-cranial material as well as a small piece of maxilla, belonging to the same individual of Brasileodactylus is presented. This is the first description of post-cranial material of this genus; as expected, there is a high degree of conformity with the other taxa. Chapter 7 summarises and shortly discusses all taxa, presents the main conclusions again, and furthermore, presents the measurements of the dentition, showing specific patterns for each taxon. The final remarks in chapter 8 offer a discussion on the problems with the Cambridge Greensands (Ornithocheiridae versus Anhangueridae). This study resulted in the refinement of various diagnoses and makes the distinction between the four taxa clearer: animals with a premaxillary and dentary sagittal crest (Coloborhynchus, Criorhynchus and Anhanguera) belong to Anhangueridae; the crestless Brasileodactylus however, cannot be classified to Anhangueridae, despite the close relationship due to the incompleteness of its remains. The diagnosis of Ornithocheiridae, as recently proposed in a re-evaluation, is not based on the type specimen and the used specimen does not show the described characters

Flavour-kinematics duality for Goldstone modes

Three scalar effective field theories have special properties in terms of non-linear symmetries, soft limits and on-shell constructability that arise from their Goldstone nature: the non-linear $\sigma$-model, multi-DBI theory and the special Galileon. We discuss how these theories are related via flavour-kinematic duality, analogous to the colour-kinematic duality between gravity and gauge theories. At the off-shell level, we identify a specific mapping between the three theories that is crucially dependent on their non-linear symmetries. Similarly, we demonstrate how the on-shell amplitudes factorise into BCJ numerators describing flavour and a scalar version of kinematics, naturally leading to the inclusion of graviton exchange in the $SO(M,N)$ non-linear $\sigma$-model. Finally, we map those numerators onto each other, and comment on a similar relation to tensor kinematics. Our results highlight a common structure that underlies the physics of different Goldstone modes.Comment: 22 pages, 4 figure

Biomechanical implications of walking with indigenous footwear

Objectives This study investigates biomechanical implications of walking with indigenous “Kolhapuri” footwear compared to barefoot walking among a population of South Indians. Materials and methods Ten healthy adults from South India walked barefoot and indigenously shod at voluntary speed on an artificial substrate. The experiment was repeated outside, on a natural substrate. Data were collected from (1) a heel‐mounted 3D‐accelerometer recording peak impact at heel contact, (2) an ankle‐mounted 3D‐goniometer (plantar/dorsiflexion and inversion/eversion), and (3) sEMG electrodes at the m. tibialis anterior and the m. gastrocnemius medialis. Results Data show that the effect of indigenous footwear on the measured variables, compared to barefoot walking, is relatively small and consistent between substrates (even though subjects walked faster on the natural substrate). Walking barefoot, compared to shod walking yields higher impact accelerations, but the differences are small and only significant for the artificial substrate. The main rotations of the ankle joint are mostly similar between conditions. Only the shod condition shows a faster ankle rotation over the rapid eversion motion on the natural substrate. Maximal dorsiflexion in late stance differs between the footwear conditions on an artificial substrate, with the shod condition involving a less dorsiflexed ankle, and the plantar flexion at toe‐off is more extreme when shod. Overall the activity pattern of the external foot muscles is similar. Discussion The indigenous footwear studied (Kolhapuri) seems to alter foot biomechanics only in a subtle way. While offering some degree of protection, walking in this type of footwear resembles barefoot gait and this type of indigenous footwear might be considered “minimal”

Boundary Objects as Dialogical Learning Accelerators for Social Change in Design for Health:Systematic Review

BACKGROUND: Boundary objects can add value for innovative design and implementation research in health care through their organizational focus and the dynamic structure between ill-structured and tailored use. However, when innovation is approached as a boundary object, more attention will need to be paid to the preimplementation phase. Research and design thinking pay attention to the preimplementation stage but do not have a social or organizational focus per se. The integration of boundary objects in design methodologies can provide a more social and organizational focus in innovative design projects by mapping out the mechanisms that occur at boundaries during design. Four dialogical learning mechanisms that can be triggered at boundaries have been described in the literature: identification, coordination, reflection, and transformation. These mechanisms seem suitable for integration in innovative design research on health. OBJECTIVE: Focusing on innovation in health, this study aims to find out whether the different learning mechanisms can be linked to studies on health innovation that mention boundary objects as a concept and assess whether the related mechanisms provide insight into the stage of the design and implementation or change process. METHODS: The following 6 databases were searched for relevant abstracts: PubMed, Scopus, Education Resources Information Center, PsycINFO, Information Science and Technology Abstracts, and Embase. These databases cover a wide range of published studies in the field of health. RESULTS: Our initial search yielded 3102 records; after removing the duplicates, 2186 (70.47%) records were screened on the title and abstract, and 25 (0.81%) papers were included; of the 13 papers where we identified 1 mechanism, 5 (38%) described an innovation or innovative project, and of the 12 papers where we identified more mechanisms, 9 (75%) described the development or implementation of an innovation. The reflective mechanism was not identified solely but was present in papers describing a more successful development or implementation project of innovation. In these papers, the predetermined goals were achieved, and the process of integration was relatively smoother. CONCLUSIONS: The concept of boundary objects has found its way into health care. Although the idea of a boundary object was introduced to describe how specific artifacts can fulfill a bridging function between different sociocultural sites and thus have a social focus, the focus in the included papers was often on the boundary object itself rather than the social effect. The reflection and transformation mechanisms were underrepresented in the included studies but based on the findings in this review, pursuing to trigger the reflective mechanism in design, development, and implementation projects can lead to a more fluid and smooth integration of innovation into practice

Neutron-enhanced information on the laboratory characterization of ancient Egyptian leathers: hydration and preservation status

The Museo Egizio’s collection contains 200 precious and unique leather artifacts belonging to different historical periods. The materials used during the tanning and curing procedures affect the chemical and elemental composition of the surface of the samples as well as their preservation status, specifically through the hydration level within the bulk. Here we provide an experimental characterization of a series of samples from Museo Egizio that document an extensive denaturation phenomenon (gelatinization), by combining non-destructive techniques including surface probes (X-ray fluorescence, Raman scattering, and scanning electron microscopy enhanced by X-ray energy spectroscopy) and neutron-based bulk techniques (inelastic and deep-inelastic neutron scattering). Results show partial dehydration of the samples in the bulk, affecting the morphology of their surface, the presence of potassium alum, and iron oxides, as well as phosphates and hydroxides related to the tanning and curing procedures. Finally, we briefly discuss the need for a versatile and adaptable software package that is capable of combining quantitative analyses with complementary techniques including morphological, elemental, and chemical composition

A new small-bodied azhdarchoid pterosaur from the Lower Cretaceous of England and its implications for pterosaur anatomy, diversity and phylogeny

BACKGROUND: Pterosaurs have been known from the Cretaceous sediments of the Isle of Wight (southern England, United Kingdom) since 1870. We describe the three-dimensional pelvic girdle and associated vertebrae of a small near-adult pterodactyloid from the Atherfield Clay Formation (lower Aptian, Lower Cretaceous). Despite acknowledged variation in the pterosaur pelvis, previous studies have not adequately sampled or incorporated pelvic characters into phylogenetic analyses. METHODOLOGY/PRINCIPAL FINDINGS: The new specimen represents the new taxon Vectidraco daisymorrisae gen. et sp. nov., diagnosed by the presence of a concavity posterodorsal to the acetabulum and the form of its postacetabular process on the ilium. Several characters suggest that Vectidraco belongs to Azhdarchoidea. We constructed a pelvis-only phylogenetic analysis to test whether the pterosaur pelvis carries a useful phylogenetic signal. Resolution in recovered trees was poor, but they approximately matched trees recovered from analyses of total evidence. We also added Vectidraco and our pelvic characters to an existing total-evidence matrix for pterosaurs. Both analyses recovered Vectidraco within Azhdarchoidea. CONCLUSIONS/ SIGNIFICANCE: The Lower Cretaceous strata of western Europe have yielded members of several pterosaur lineages, but Aptian pterosaurs from western Europe are rare. With a pelvis length of 40 mm, the new animal would have had a total length of c. 350 mm, and a wingspan of c. 750 mm. Barremian and Aptian pterodactyloids from western Europe show that small-bodied azhdarchoids lived alongside ornithocheirids and istiodactylids. This assemblage is similar in terms of which lineages are represented to the coeval beds of Liaoning, China; however, the number of species and specimens present at Liaoning is much higher. While the general phylogenetic composition of western European and Chinese communities appear to have been approximately similar, the differences may be due to different palaeoenvironmental and depositional settings. The western Europe pterodactyloid record may therefore be artificially low in diversity due to preservational factors

New Insights into the Skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea)

The skull of the Cretaceous pterosaur Istiodactylus latidens, a historically important species best known for its broad muzzle of interlocking, lancet-shaped teeth, is almost completely known from the broken remains of several individuals, but the length of its jaws remains elusive. Estimates of I. latidens jaw length have been exclusively based on the incomplete skull of NHMUK R3877 and, perhaps erroneously, reconstructed by assuming continuation of its broken skull pieces as preserved in situ. Here, an overlooked jaw fragment of NHMUK R3877 is redescribed and used to revise the skull reconstruction of I. latidens. The new reconstruction suggests a much shorter skull than previously supposed, along with a relatively tall orbital region and proportionally slender maxilla, a feature documented in the early 20th century but ignored by all skull reconstructions of this species. These features indicate that the skull of I. latidens is particularly distinctive amongst istiodactylids and suggests greater disparity between I. latidens and I. sinensis than previously appreciated. A cladistic analysis of istiodactylid pterosaurs incorporating new predicted I. latidens skull metrics suggests Istiodactylidae is constrained to five species (Liaoxipterus brachyognathus, Lonchengpterus zhoai, Nurhachius ignaciobritoi, Istiodactylus latidens and Istiodactylus sinensis) defined by their distinctive dentition, but excludes the putative istiodactylids Haopterus gracilis and Hongshanopterus lacustris. Istiodactylus latidens, I. sinensis and Li. brachyognathus form an unresolved clade of derived istiodactylids, and the similarity of comparable remains of I. sinensis and Li. brachyognathus suggest further work into their taxonomy and classification is required. The new skull model of I. latidens agrees with the scavenging habits proposed for these pterosaurs, with much of their cranial anatomy converging on that of habitually scavenging birds