Stress wave dispersion can result in the loss or distortion of critical high-frequency data during high-strain-rate material tests or blast loading experiments. The purpose of this work is to demonstrate the benefits of correcting stress wave dispersion in split-Hopkinson pressure bar experiments under various testing situations. To do this, an innovative computational algorithm, SHPB_Processing.
View Article and Find Full Text PDFDoes the visual system adapt to number? For more than fifteen years, most have assumed that the answer is an unambiguous "yes". Against this prevailing orthodoxy, we recently took a critical look at the phenomenon, questioning its existence on both empirical and theoretical grounds, and providing an alternative explanation for extant results (the old news hypothesis). We subsequently received two critical responses.
View Article and Find Full Text PDFThe visual system adapts to a wide range of visual features, from lower-level features like color and motion to higher-level features like causality and, perhaps, number. According to some, adaptation is a strictly perceptual phenomenon, such that the presence of adaptation licenses the claim that a feature is truly perceptual in nature. Given the theoretical importance of claims about adaptation, then, it is important to understand exactly when the visual system does and does not exhibit adaptation.
View Article and Find Full Text PDFThe approximate number system (ANS) enables organisms to represent the approximate number of items in an observed collection, quickly and independently of natural language. Recently, it has been proposed that the ANS goes beyond representing natural numbers by extracting and representing rational numbers (Clarke & Beck, 2021a). Prior work demonstrates that adults and children discriminate ratios in an approximate and ratio-dependent manner, consistent with the hallmarks of the ANS.
View Article and Find Full Text PDFIt is often assumed that adaptation - a temporary change in sensitivity to a perceptual dimension following exposure to that dimension - is a litmus test for what is and is not a "primary visual attribute". Thus, papers purporting to find evidence of number adaptation motivate a claim of great significance: That number is something that can be seen in much the way that canonical visual features, like color, contrast, size, and speed, can. Fifteen years after its reported discovery, number adaptation's existence seems to be nearly undisputed, with dozens of papers documenting support for the phenomenon.
View Article and Find Full Text PDFBackground: Sestrins (SESN1-3) act as proximal sensors in leucine-induced activation of the protein kinase mechanistic target of rapamycin (mTOR) in complex 1 (mTORC1), a key regulator of cell growth and metabolism.
Objective: In the present study, the hypothesis that SESNs also mediate glucose-induced activation of mTORC1 was tested.
Methods: Rats underwent overnight fasting, and in the morning, either saline or a glucose solution (4 g⋅kg BW/10 mL⋅kg) was administered by oral gavage; mTORC1 activation in the tibialis anterior muscle was assessed.
The design of blast-resistant structures and protective systems requires a firm understanding of the loadings imparted to structures by blast waves. While empirical methods can reliably predict these loadings in the far field, there is currently a lack of understanding on the pressures experienced in the very near field, where physics-based numerical modelling and semi-empirical fast-running engineering model predictions can vary by an order of magnitude. In this paper, we present the design of an experimental facility capable of providing definitive spatially and temporally resolved reflected pressure data in the extreme near field (Z<0.
View Article and Find Full Text PDFThe understanding of blast loads is critical for the development of infrastructure that protects against explosions. However, the lack of high-quality experimental work on the characterisation of such loads prevents a better understanding of many scenarios. Blast loads are typically characterised by use of some form of pressure gauge, from which the temperature can be inferred from a pressure measurement.
View Article and Find Full Text PDFIn our target article, we argued that the number sense represents natural and rational numbers. Here, we respond to the 26 commentaries we received, highlighting new directions for empirical and theoretical research. We discuss two background assumptions, arguments against the number sense, whether the approximate number system (ANS) represents numbers or numerosities, and why the ANS represents rational (but not irrational) numbers.
View Article and Find Full Text PDFBackground: Pediatric emergency medicine (PEM) has seen little progression toward a standardized PEM educational framework. The 2018 Consensus Conference on Advancing PEM Education addressed this gap in core EM education. Absent elements include a "broad needs assessment to identify and evaluate existing curricula and systems gaps in EM training" and a "clearly defined core PEM curriculum that unifies and drives the learning process.
View Article and Find Full Text PDFOn a now orthodox view, humans and many other animals possess a "number sense," or approximate number system (ANS), that represents number. Recently, this orthodox view has been subject to numerous critiques that question whether the ANS genuinely represents number. We distinguish three lines of critique - the arguments from congruency, confounds, and imprecision - and show that none succeed.
View Article and Find Full Text PDFWhile it is well known that detonation of shallow-buried high explosive charges generally results in above-surface loading which is greatly amplified compared with the same detonation in air, uncertainty persists as to the mechanisms leading to this effect. The work presented in this paper is a systematic investigation into the mechanisms of load transfer in buried blast events. This paper details the results from a parametric study into the mechanisms and magnitudes of load transfer following a shallow-buried explosion, where spatial and temporal load distributions are directly measured on a rigid surface using an array of Hopkinson pressure bars.
View Article and Find Full Text PDFJoint actions often require agents to track others' actions while planning and executing physically incongruent actions of their own. Previous research has indicated that this can lead to visuomotor interference effects when it occurs outside of joint action. How is this avoided or overcome in joint actions? We hypothesized that when joint action partners represent their actions as interrelated components of a plan to bring about a joint action goal, each partner's movements need not be represented in relation to distinct, incongruent proximal goals.
View Article and Find Full Text PDFA recent empirical study claims to show that the answer to Molyneux's question is negative, but, as John Schwenkler points out, its findings are inconclusive: Subjects tested in this study probably lacked the visual acuity required for a fair assessment of the question. Schwenkler is undeterred. He argues that the study could be improved by lowering the visual demands placed on subjects, a suggestion later endorsed and developed by Kevin Connolly.
View Article and Find Full Text PDFA working group at the 2012 Academic Emergency Medicine consensus conference on education research in emergency medicine (EM) convened to develop a curriculum for dedicated postgraduate fellowships in EM education scholarship. This fellowship is intended to create future education scholars, equipped with the skills to thrive in academic careers. This proceedings article reports on the consensus of a breakout session subgroup tasked with defining a common core content for education scholarship fellowships.
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