Flightless birds are not neuroanatomical analogs of non-avian dinosaurs.

BACKGROUND: In comparative neurobiology, major transitions in behavior are thought to be associated with proportional size changes in brain regions. Bird-line theropod dinosaurs underwent a drastic locomotory shift from terrestrial to volant forms, accompanied by a suite of well-documented postcranial adaptations. To elucidate the potential impact of this locomotor shift on neuroanatomy, we first tested for a correlation between loss of flight in extant birds and whether the brain morphology of these birds resembles that of their flightless, non-avian dinosaurian ancestors. We constructed virtual endocasts of the braincase for 80 individuals of non-avian and avian theropods, including 25 flying and 19 flightless species of crown group birds. The endocasts were analyzed using a three-dimensional (3-D) geometric morphometric approach to assess changes in brain shape along the dinosaur-bird transition and secondary losses of flight in crown-group birds (Aves). RESULTS: While non-avian dinosaurs and crown-group birds are clearly distinct in endocranial shape, volant and flightless birds overlap considerably in brain morphology. Phylogenetically informed analyses show that locomotory mode does not significantly account for neuroanatomical variation in crown-group birds. Linear discriminant analysis (LDA) also indicates poor predictive power of neuroanatomical shape for inferring locomotory mode. Given current sampling, Archaeopteryx, typically considered the oldest known bird, is inferred to be terrestrial based on its endocranial morphology. CONCLUSION: The results demonstrate that loss of flight does not correlate with an appreciable amount of neuroanatomical changes across Aves, but rather is partially constrained due to phylogenetic inertia, evident from sister taxa having similarly shaped endocasts. Although the present study does not explicitly test whether endocranial changes along the dinosaur-bird transition are due to the acquisition of powered flight, the prominent relative expansion of the cerebrum, in areas associated with flight-related cognitive capacity, suggests that the acquisition of flight may have been an important initial driver of brain shape evolution in theropods.

Giant taxon-character matrices: the future of morphological systematics.

Simões et al. () argued that large matrices are linked to the construction of "problematic" characters, and that those characters negatively affect tree topology. In their re-evaluation of two squamate datasets, however, Simões et al. () simply eliminated what they termed "problematic" characters, rather than recode them. This practice ignores potential sources of phylogenetic information and, if it were to be more widely followed, would inhibit the advancement of the field of systematics. Here, we defend the necessity and inevitability of large morphological (phenomic) datasets and discuss best practices for morphological data collection in contemporary phylogenetics.

Tempo and Pattern of Avian Brain Size Evolution.

Relative brain sizes in birds can rival those of primates, but large-scale patterns and drivers of avian brain evolution remain elusive. Here, we explore the evolution of the fundamental brain-body scaling relationship across the origin and evolution of birds. Using a comprehensive dataset sampling> 2,000 modern birds, fossil birds, and theropod dinosaurs, we infer patterns of brain-body co-variation in deep time. Our study confirms that no significant increase in relative brain size accompanied the trend toward miniaturization or evolution of flight during the theropod-bird transition. Critically, however, theropods and basal birds show weaker integration between brain size and body size, allowing for rapid changes in the brain-body relationship that set the stage for dramatic shifts in early crown birds. We infer that major shifts occurred rapidly in the aftermath of the Cretaceous-Paleogene mass extinction within Neoaves, in which multiple clades achieved higher relative brain sizes because of a reduction in body size. Parrots and corvids achieved the largest brains observed in birds via markedly different patterns. Parrots primarily reduced their body size, whereas corvids increased body and brain size simultaneously (with rates of brain size evolution outpacing rates of body size evolution). Collectively, these patterns suggest that an early adaptive radiation in brain size laid the foundation for subsequent selection and stabilization.

The comparative efficacy and risk of harms of the intravenous and subcutaneous formulations of trastuzumab in patients with HER2-positive breast cancer: a rapid review.

BACKGROUND: Trastuzumab is a monoclonal antibody for patients with HER2 (human epidermal growth factor receptor 2)-positive breast cancer, which is added to regular treatment and reduces mortality. Originally, trastuzumab had to be administered intravenously (IV) over 30 min every 3 weeks for 1 year. Since 2012, a formulation for the subcutaneous (SC) administration of trastuzumab has been available, which has not yet been approved in the USA. Advocates claim that the SC formulation saves time and money, despite higher costs. The purpose of this study is to review existing literature concerning the comparative efficacy and risk of harms of trastuzumab IV and SC concerning patient-relevant health outcomes. METHODS: We conducted searches in the Cochrane Library and MEDLINE for articles published through May 2018 in English or German. In addition, we searched ClinicalTrials.gov to identify unpublished studies. We dually reviewed the abstracts and full-text articles based on a priori defined inclusion criteria, rated the risk of bias of included studies, and assessed the strength of the evidence for each outcome of interest. Because data was insufficient for quantitative synthesis, we summarized results narratively. RESULTS: We identified three RCTs (randomized controlled trials) meeting our eligibility criteria, which included data on 1003 patients. We found moderate evidence for similar event rates (20.05% vs. 18%, HR (hazard ratio) 0.88, CI 95% = 0.62-1.27), and mortality rates (10% vs. 8%, HR 0.76, CI 95% = 0.44-1.32) after 1.7 years for patients receiving trastuzumab IV and for patients receiving SC. Results remained similar after 3.3 years, though evidence lacked strength due to a high dropout rate. All trials reported more adverse events among the SC group than in the IV group. Evidence for these findings was of moderate strength. Nevertheless, more than 85% of the patients preferred trastuzumab SC over IV. Results concerning serious adverse events appeared to be heterogeneous. CONCLUSION: Results of studies indicate similar efficacy between the two routes of administration. The higher rates of adverse events for SC administration were mainly attributable to injection site-related events. The clinical decision of whether to administer trastuzumab SC or IV requires the consideration of several factors and should be determined individually.

Rapid 18F-FDG Uptake in Brain of Awake, Behaving Rat and Anesthetized Chicken has Implications for Behavioral PET Studies in Species With High Metabolisms.

Brain-behavior studies using 18F-FDG PET aim to reveal brain regions that become active during behavior. In standard protocols, 18F-FDG is injected, the behavior is executed during 30-60 min of tracer uptake, and then the animal is anesthetized and scanned. Hence, the uptake of 18F-FDG is not itself observed and could, in fact, be complete in very little time. This has implications for behavioral studies because uptake is assumed to reflect concurrent behavior. Here, we utilized a new, miniature PET scanner termed RatCAP to measure uptake simultaneously with behavior. We employed a novel injection protocol in which we administered 18F-FDG (i.v.) four times over two 2 h to allow for repeated measurements and the correlation of changes in uptake and behavioral activity. Furthermore, using standard PET methods, we explored the effects of injection route on uptake time in chickens, a model for avians, for which PET studies are just beginning. We found that in the awake, behaving rat most of the 18F-FDG uptake occurred within minutes and overlapped to a large extent with 18F-FDG data taken from longer uptake periods. By contrast, behavior which occurred within minutes of the 18F-FDG infusion differed markedly from the behavior that occurred during later uptake periods. Accordingly, we found that changes in 18F-FDG uptake in the striatum, motor cortex and cerebellum relative to different reference regions significantly predicted changes in behavioral activity during the scan, if the time bins used for correlation were near the injection times of 18F-FDG. However, when morphine was also injected during the scan, which completely abolished behavioral activity for over 50 min, a large proportion of the variance in behavioral activity was also explained by the uptake data from the entire scan. In anesthetized chickens, tracer uptake was complete in about 80 min with s.c. injection, but 8 min with i.v. injection. In conclusion, uptake time needs to be taken into account to more accurately correlate PET and behavioral data in mammals and avians. Additionally, RatCAP together with multiple, successive injections of 18F-FDG may be useful to explore changes in uptake over time in relation to changes in behavior.

Flying starlings, PET and the evolution of volant dinosaurs.

Birds have evolved behavioral and morphological adaptations for powered flight. Many aspects of this transition are unknown, including the neuroanatomical changes that made flight possible [1]. To understand how the avian brain drives this complex behavior, we utilized positron emission tomography (PET) scanning and the tracer (18)F-fluorodeoxyglucose (FDG) to document regional metabolic activity in the brain associated with a variety of locomotor behaviors. FDG studies are typically employed in rats [2] though the technology has been applied to birds [3]. We examined whole-brain function in European Starlings (Sturnus vulgaris), trained to fly in a wind tunnel while metabolizing the tracer. Drawing on predictions from early anatomical studies [4], we hypothesized increased metabolic activity in the Wulst and functionally related visual brain regions during flight. We found that flight behaviors correlated positively with entopallia and Wulst activity, but negatively with thalamic activity.

Vertebral Pneumaticity in the Ornithomimosaur Archaeornithomimus (Dinosauria: Theropoda) Revealed by Computed Tomography Imaging and Reappraisal of Axial Pneumaticity in Ornithomimosauria.

Among extant vertebrates, pneumatization of postcranial bones is unique to birds, with few known exceptions in other groups. Through reduction in bone mass, this feature is thought to benefit flight capacity in modern birds, but its prevalence in non-avian dinosaurs of variable sizes has generated competing hypotheses on the initial adaptive significance of postcranial pneumaticity. To better understand the evolutionary history of postcranial pneumaticity, studies have surveyed its distribution among non-avian dinosaurs. Nevertheless, the degree of pneumaticity in the basal coelurosaurian group Ornithomimosauria remains poorly known, despite their potential to greatly enhance our understanding of the early evolution of pneumatic bones along the lineage leading to birds. Historically, the identification of postcranial pneumaticity in non-avian dinosaurs has been based on examination of external morphology, and few studies thus far have focused on the internal architecture of pneumatic structures inside the bones. Here, we describe the vertebral pneumaticity of the ornithomimosaur Archaeornithomimus with the aid of X-ray computed tomography (CT) imaging. Complementary examination of external and internal osteology reveals (1) highly pneumatized cervical vertebrae with an elaborate configuration of interconnected chambers within the neural arch and the centrum; (2) anterior dorsal vertebrae with pneumatic chambers inside the neural arch; (3) apneumatic sacral vertebrae; and (4) a subset of proximal caudal vertebrae with limited pneumatic invasion into the neural arch. Comparisons with other theropod dinosaurs suggest that ornithomimosaurs primitively exhibited a plesiomorphic theropod condition for axial pneumaticity that was extended among later taxa, such as Archaeornithomimus and large bodied Deinocheirus. This finding corroborates the notion that evolutionary increases in vertebral pneumaticity occurred in parallel among independent lineages of bird-line archosaurs. Beyond providing a comprehensive view of vertebral pneumaticity in a non-avian coelurosaur, this study demonstrates the utility and need of CT imaging for further clarifying the early evolutionary history of postcranial pneumaticity.

An expanded combined evidence approach to the Gavialis problem using geometric morphometric data from crocodylian braincases and Eustachian systems.

The phylogenetic position of the Indian gharial (Gavialis gangeticus) is disputed--morphological characters place Gavialis as the sister to all other extant crocodylians, whereas molecular and combined analyses find Gavialis and the false gharial (Tomistoma schlegelii) to be sister taxa. Geometric morphometric techniques have only begun to be applied to this issue, but most of these studies have focused on the exterior of the skull. The braincase has provided useful phylogenetic information for basal crurotarsans, but has not been explored for the crown group. The Eustachian system is thought to vary phylogenetically in Crocodylia, but has not been analytically tested. To determine if gross morphology of the crocodylian braincase proves informative to the relationships of Gavialis and Tomistoma, we used two- and three-dimensional geometric morphometric approaches. Internal braincase images were obtained using high-resolution computerized tomography scans. A principal components analysis identified that the first component axis was primarily associated with size and did not show groupings that divide the specimens by phylogenetic affinity. Sliding semi-landmarks and a relative warp analysis indicate that a unique Eustachian morphology separates Gavialis from other extant members of Crocodylia. Ontogenetic expansion of the braincase results in a more dorsoventrally elongate median Eustachian canal. Changes in the shape of the Eustachian system do provide phylogenetic distinctions between major crocodylian clades. Each morphometric dataset, consisting of continuous morphological characters, was added independently to a combined cladistic analysis of discrete morphological and molecular characters. The braincase data alone produced a clade that included crocodylids and Gavialis, whereas the Eustachian data resulted in Gavialis being considered a basally divergent lineage. When each morphometric dataset was used in a combined analysis with discrete morphological and molecular characters, it generated a tree that matched the topology of the molecular phylogeny of Crocodylia.