HMA Spec Revisions and Testing 2018

INDOT’s HMA specifications and testing procedures are changing for 2018. We will present a summary of those changes, and what to expect

Superpave5: What is It?

INDOT revised the asphalt specification in 2019 based on the concept of Superpave 5—that higher in-place density yields improved performance disability. This session will provide insight into the science of how Superpave 5 works while giving designers an understanding of how it affects design and construction specifications

Legal framework for small autonomous agricultural robots

Legal structures may form barriers to, or enablers of, adoption of precision agriculture management with small autonomous agricultural robots. This article develops a conceptual regulatory framework for small autonomous agricultural robots, from a practical, self-contained engineering guide perspective, sufficient to get working research and commercial agricultural roboticists quickly and easily up and running within the law. The article examines the liability framework, or rather lack of it, for agricultural robotics in EU, and their transpositions to UK law, as a case study illustrating general international legal concepts and issues. It examines how the law may provide mitigating effects on the liability regime, and how contracts can be developed between agents within it to enable smooth operation. It covers other legal aspects of operation such as the use of shared communications resources and privacy in the reuse of robot-collected data. Where there are some grey areas in current law, it argues that new proposals could be developed to reform these to promote further innovation and investment in agricultural robots

Defective Presynaptic Choline Transport Underlies Hereditary Motor Neuropathy

The neuromuscular junction (NMJ) is a specialized synapse with a complex molecular architecture that provides for reliable transmission between the nerve terminal and muscle fiber. Using linkage analysis and whole-exome sequencing of DNA samples from subjects with distal hereditary motor neuropathy type VII, we identified a mutation in SLC5A7, which encodes the presynaptic choline transporter (CHT), a critical determinant of synaptic acetylcholine synthesis and release at the NMJ. This dominantly segregating SLC5A7 mutation truncates the encoded product just beyond the final transmembrane domain, eliminating cytosolic-C-terminus sequences known to regulate surface transporter trafficking. Choline-transport assays in both transfected cells and monocytes from affected individuals revealed significant reductions in hemicholinium-3-sensitive choline uptake, a finding consistent with a dominant-negative mode of action. The discovery of CHT dysfunction underlying motor neuropathy identifies a biological basis for this group of conditions and widens the spectrum of disorders that derive from impaired NMJ transmission. Our findings compel consideration of mutations in SLC5A7 or its functional partners in relation to unexplained motor neuronopathies

Natural experiments for the evaluation of place-based public health interventions:a methodology scoping review

Place-based public health evaluations are increasingly making use of natural experiments. This scoping review aimed to provide an overview of the design and use of natural experiment evaluations (NEEs), and an assessment of the plausibility of the as-if randomisation assumption. A systematic search of three bibliographic databases (Pubmed, Web of Science and Ovid-Medline) was conducted in January 2020 to capture publications that reported a natural experiment of a place-based public health intervention or outcome. For each, study design elements were extracted. An additional evaluation of as-if randomisation was conducted by twelve 12 of this paper’s authors who evaluated the same set of 20 randomly selected studies and assessed ‘as-if’ randomisation for each. 366 NEE studies of place-based public health interventions were identified. The most commonly used NEE approach was a Difference-in-Differences study design (25%), followed by before-after comparisons studies (23%) and regression analysis studies. 42% of NEEs had likely or probably as-if randomisation of exposure (the intervention), while for 25% this was implausible. An inter-rater agreement exercise indicated poor reliability of as-if randomisation assignment. Only about half of NEEs reported some form of sensitivity or falsification analysis to support inferences. NEEs are conducted using many different designs and statistical methods and encompass various definitions of a natural experiment, while it is questionable whether all evaluations reported as natural experiments should be considered as such. The likelihood of as-if randomisation should be specifically reported, and primary analyses should be supported by sensitivity analyses and/or falsification tests. Transparent reporting of NEE designs and evaluation methods will contribute to the optimum use of place-based NEEs

The politics of climate change in Australia

Global climate change has become one of the most contentious and divisive issues in Australian politics. In part, this reflects the nature of the problem itself and Australia’s vulnerability both to manifestations of climate change on one hand and its mitigation on the other. While a land of heat and drought, and still a major agricultural producer, Australia also has an immediate economic interest in the maintenance of a global fossil fuel economy given its status as the world’s largest exporter of coal. And while Australia has one of the world’s oldest Green political parties, its citizens are also among the largest per-capita greenhouse gas emitters in the world. With this context it is unsurprising that action on climate change should be contentious and climate change might indeed be defined as a “wicked” or “diabolical” problem.1 Yet the frequency and ferocity of contestation in Australia within the last decade over how to respond to climate change has been stunning, as has the oscillation of public opinion on whether, and how, to act in response to global climate change. Making sense of these dynamics is not simply a matter of pointing to the opposition of different interests. It also requires attention to the ways in which the problem and responses to it have been framed; how different groups have mobilized in support or opposition to climate change action and in what sites; how public debate has evolved and been influenced by changing domestic and international contexts; and what policy responses have ultimately been pursued in response, with what effects. These are questions of politics, and the questions that animate both this special issue and the papers that constitute it. If politics can be understood as a site of contestation over the values of a society, how they might be protected or advanced and how risks and costs should be distributed across that society, no issue has seemed to compel such radically different and oppositional responses (both in parliament and in public debate) as climate change

Local Metrical and Global Topological Maps in the Hybrid Spatial Semantic Hierarchy

Topological and metrical methods for representing spatial knowledge have complementary strengths. We present a hybrid extension to the Spatial Semantic Hierarchy that combines their strengths and avoids their weaknesses. Metrical SLAM methods are used to build local maps of small-scale space within the sensory horizon of the agent, while topological methods are used to represent the structure of large-scale space. We describe how a local perceptual map is analyzed to identify a local topology description and is abstracted to a topological place. The mapbuilding method creates a set of topological map hypotheses that are consistent with travel experience. The set of maps is guaranteed under reasonable assumptions to include the correct map. We demonstrate the method on a real environment with multiple nested large-scale loops

Integrating multiple representations of spatial knowledge for mapping, navigation, and communication

A robotic chauffeur should reason about spatial information with a variety of scales, dimensions, and ontologies. Rich representations of both the quantitative and qualitative characteristics of space not only enable robust navigation behavior, but also permit natural communication with a human passenger. We apply a hierarchical framework of spatial knowledge inspired by human cognitive abilities, the Hybrid Spatial Semantic Hierarchy, to common navigation tasks: safe motion, localization, map-building, and route planning. We also discuss the straightforward mapping between the variety of ways in which people communicate with a chauffeur and the framework’s heterogeneous concepts of spatial knowledge. We present pilot experiments with a virtual chauffeur