Retrodeformation and muscular reconstruction of ornithomimosaurian dinosaur crania

Ornithomimosaur dinosaurs evolved lightweight, edentulous skulls that possessed keratinous rhamphothecae. Understanding the anatomy of these taxa allows for a greater understanding of “ostrich-mimic” dinosaurs and character change during theropod dinosaur evolution. However, taphonomic processes during fossilisation often distort fossil remains. Retrodeformation offers a means by which to recover a hypothesis of the original anatomy of the specimen, and 3D scanning technologies present a way to constrain and document the retrodeformation process. Using computed tomography (CT) scan data, specimen specific retrodeformations were performed on three-dimensionally preserved but taphonomically distorted skulls of the deinocheirid Garudimimus brevipes Barsbold, 1981 and the ornithomimids Struthiomimus altus Lambe, 1902 and Ornithomimus edmontonicus Sternberg, 1933. This allowed for a reconstruction of the adductor musculature, which was then mapped onto the crania, from which muscle mechanical advantage and bite forces were calculated pre- and post-retrodeformation. The extent of the rhamphotheca was varied in each taxon to represent morphologies found within modern Aves. Well constrained retrodeformation allows for increased confidence in anatomical and functional analysis of fossil specimens and offers an opportunity to more fully understand the soft tissue anatomy of extinct taxa

Regulating Medicines in a Globalized World With Increased Recognition and Reliance Among Regulators: A National Academies Report

Research and development of pharmaceuticals are now complex global endeavors, with drug companies operating worldwide using global supply chains. Pharmaceutical companies source their products from many countries, conduct trials in multiple sites, and market essential drugs and vaccines globally. Yet oversight of drug safety and effectiveness is primarily the responsibility of national regulators of variable capacities. National agencies often undertake product reviews without recognizing that similar reviews are occurring elsewhere, sometimes simultaneously. The result is duplication and redundancy, which benefits neither national nor global public health. Supported by the US Food and Drug Administration (FDA), the National Academies of Sciences, Engineering, and Medicine convened an expert committee to explore the benefits of mutual recognition and other reliance activities among regulators. Even well-resourced regulators (for example, the FDA, the European Medicines Agency, the Pharmaceutical and Medical Devices Agency Japan, and Health Canada) find it difficult to ensure the safety, efficacy, and quality of medicines in a globalized world. Regulatory failures cause harm to the population and undermine public trust in government. In 2008, following discovery of contaminated heparin originating from China, the Bush administration authorized the FDA to coordinate certain product manufacturing inspections with Australian and European regulators in China and India—setting the stage for “third country” inspections (ie, inspections conducted outside the jurisdiction of either regulator). Yet concerns about the quality of active pharmaceutical ingredients and finished pharmaceutical products persist. For example, in 2018, the FDA recalled generic medications used to treat hypertension and cardiovascular disease because of contamination

Inaugural BMC Ecology and Evolution image competition: the winning images

The inaugural BMC Ecology and Evolution image competition attracted entries from talented ecologists and evolutionary biologists worldwide. Together, these photos beautifully capture biodiversity, how it arose and why we should conserve it. This editorial celebrates the winning images as selected by the Editor of BMC Ecology and Evolution and senior members of the journal’s editorial board

Metastability of non-reversible mean-field Potts model with three spins

We examine a non-reversible, mean-field Potts model with three spins on a set with $N\uparrow\infty$ points. Without an external field, there are three critical temperatures and five different metastable regimes. The analysis can be extended by a perturbative argument to the case of small external fields. We illustrate the case of large external fields with some phenomena which are not present in the absence of external field.Comment: 34 pages, 12 figure

Should I stay or should I go? Exit options within mixed systems of public and private health care finance

Mixed public–private finance is widespread in health care systems internationally. In one variant of mixed finance, some countries (e.g., Germany) allow eligible beneficiaries to fully exit from the public (social insurance) system and purchase private insurance. Using a controlled laboratory experiment, we empirically investigate the predictions of a political economy model of mixed systems of public and private finance with two types of exit: universal-exit, when all individuals can choose to exit the public system, and conditional-exit, when only individuals with an income at or above a threshold income level can choose to exit. We find that high-income individuals are less likely to exit under universal-exit than under conditional-exit, despite having the same incentive to exit in both treatments. Sensitivity treatments suggests that a number of factors may be at play in explaining this result, including learning effects, a priming effect and a framing effect, but that other-regarding preferences do not appear to be an important factor

Support for public provision of a private good with top-up and opt-out: A controlled laboratory experiment

This paper presents the results of a revealed-choice experiment testing the theoretical predictions of political economy models regarding public support for a publicly provided private good financed with proportional income taxes when individuals can purchase the good privately and either continue to consume public provision (‘top-up’) or forego public provision (‘opt-out’), but in each case continue to pay income taxes. Our laboratory results confirm behavior is consistent with the predicted majority-preferred tax rate under mixed financing with top-up, but we identify preferences for significantly higher rates of public provision than predicted under mixed financing with opt-out. Using non parametric regression analysis, we explore the relationship between individuals’ top-up and opt-out decisions and both their income levels and the implemented tax rates

A Behavioral Economic Study of Tax Rate Selection by the Median Voter: Can the Tax Rate Be Influenced by the Name of the Publicly Provided Private Good?

This paper presents the results of a behavioral economics study to test if the tax rates submitted to finance the public provision of a private good are influenced by changing the name of the private good. A revealed-preference laboratory decision-making experiment is used to test if participants choose significantly different tax rates to support provision of a private good named as a health care investment compared to an identical good named as a neutral monetary investment. Although some previous studies focusing on both framing and context effects find differences associated with health versus non-health environments, these studies have not involved voting over public provision of a private good. In our experimental environment, participants with different income endowments provide their preferred proportional tax rates for financing public provision of a private good in either a neutral or a health context. The implemented tax rate is the median preferred tax rate, and once the budget is determined, each participant receives the same quantity of the publicly provided private good. In each context, the payoff functions are the same. The only difference between the contexts is the name attached to the publicly provided private good, regardless of the name attached to the publicly provided private good, consuming it imposes no externalities. This controls for the positive externality characteristics of many health care goods, but not for preferences evoked by the merit good character of health care which factor into decisions about the public provision of health care. We find that the theoretical predictions of the median voter model are generally supported by the data. However, the conjecture that the implemented tax rate would be affected by context is not supported by the results

Feeding mechanics in spinosaurid theropods and extant crocodilians

A number of extant and extinct archosaurs evolved an elongate, narrow rostrum. This longirostrine condition has been associated with a diet comprising a higher proportion of fish and smaller prey items compared to taxa with broader, more robust snouts. The evolution of longirostrine morphology and a bulbous anterior rosette of premaxillary teeth also occurs in the spinosaurid theropod dinosaurs, leading to suggestions that at least some members of this clade also had a diet comprising a notable proportion of fish or other small vertebrates. Here we compare the rostral biomechanics of the spinosaurs Baryonyx walkeri and Spinosaurus c.f. S. aegyptiacus to three extant crocodilians: two longistrine taxa, the African slender-snouted crocodile Mecistops cataphractus and the Indian gharial Gavialis gangeticus; and the American alligator Alligator mississippiensis. Using computed tomography (CT) data, the second moments of area and moments of inertia at successive transverse slices along the rostrum were calculated for each of the species. Size-independent results tested the biomechanical benefits of material distribution within the rostra. The two spinosaur rostra were both digitally reconstructed from CT data and compared against all three crocodilians. Results show that African slender-snouted crocodile skulls are more resistant to bending than an equivalent sized gharial. The alligator has the highest resistances to bending and torsion of the crocodiles for its size and greater than that of the spinosaurs. The spinosaur rostra possess similar resistance to bending and torsion despite their different morphologies. When size is accounted for, B. walkeri performs mechanically differently from the gharial, contradicting previous studies whereas Spinosaurus does not. Biomechanical data support known feeding ecology for both African slender-snouted crocodile and alligator, and suggest that the spinosaurs were not obligate piscivores with diet being determined by individual animal size