Towards Python-based Domain-specific Languages for Self-reconfigurable Modular Robotics Research

This paper explores the role of operating system and high-level languages in the development of software and domain-specific languages (DSLs) for self-reconfigurable robotics. We review some of the current trends in self-reconfigurable robotics and describe the development of a software system for ATRON II which utilizes Linux and Python to significantly improve software abstraction and portability while providing some basic features which could prove useful when using Python, either stand-alone or via a DSL, on a self-reconfigurable robot system. These features include transparent socket communication, module identification, easy software transfer and reliable module-to-module communication. The end result is a software platform for modular robots that where appropriate builds on existing work in operating systems, virtual machines, middleware and high-level languages.Comment: Presented at DSLRob 2011 (arXiv:1212.3308

Cranial morphology of embrithosaurus schwarzi (Parareptilia, Pareiasauria) and a taxonomic and stratigraphic reassessment of the South African Middle Permian Pareiasaurs

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Master of Science. Johannesburg, 2016.Pareiasaurs were abundant, large, herbivorous parareptiles of the middle and late Permian which had a global distribution. The most basal pareiasaurs are found only in the middle Permian of South Africa, suggesting a Gondwanan origin for the group. Despite their relative abundance, most pareiasaurs are poorly known, especially the large middle Permian South African taxa that went extinct at the end of the Tapinocephalus Assemblage Zone. Historic taxonomic confusion was reduced with studies by Lee (1995, 1997a) that addressed the alpha-taxonomy of all pareiasaurs. He reduced the middle Permian South African pareiasaurs from 11 to four species: Bradysaurus baini, B. seeleyi, Embrithosaurus schwarzi and Nochelesaurus alexanderi. However this revision did not include detailed anatomical descriptions of any of the middle Permian South African Tapinocephalus Assemblage Zone taxa. The first detailed cranial description of Embrithosaurus schwarzi is presented in this contribution. Within the middle Permian pareiasaurians, Embrithosaurus has unique wide, short and stubby teeth with nine marginal cusps arranged more regularly. A cranial taxonomic reassessment of all middle Permian pareiasaurs has confirmed the validity of the four taxa identified by Lee and produced updated cranial diagnoses for each species. Diagnostic features noted by Lee and retained include an autapomorphic large distinctive maxillary boss on a strongly buckled or bent maxilla for B. baini, distinctive horizontally flat and pointed bosses on the posterior margin of the quadratojugal for Nochelesaurus and the smallest cheek flanges for B. seeleyi. Using the updated diagnoses, re-identification of 39 specimens out of 108 studied has produced updated biostratigraphic ranges for the middle Permian species. B. seeleyi is the first to make an appearance, in the middle Koornplaats Member of the Abrahamskraal Formation. B. baini first appears in the upper iii Koornplaats Member, Nochelesaurus in the Swaerskraal Member, and Embrithosaurus in the lower Moordenaars Member of the Abrahamskraal Formation. All taxa disappear by the top of the Karelskraal Member of the Abrahamskraal Formation, confirming that all the middle Permian pareiasaur species went extinct at the end of the Tapinocephalus Assemblage Zone.MT201

Electronic properties of graphene multilayers

We study the effects of disorder in the electronic properties of graphene multilayers, with special focus on the bilayer and the infinite stack. At low energies and long wavelengths, the electronic self-energies and density of states exhibit behavior with divergences near half-filling. As a consequence, the spectral functions and conductivities do not follow Landau's Fermi liquid theory. In particular, we show that the quasiparticle decay rate has a minimum as a function of energy, there is a universal minimum value for the in-plane conductivity of order e^2/h per plane and, unexpectedly, the c-axis conductivity is enhanced by disorder at low doping, leading to an enormous conductivity anisotropy at low temperatures.Comment: 4 pages, 4 figure. Reference to exciting new ARPES results on graphite added (we thank A. Lanzara for sharing the paper prior to its publication

Globular and disordered-the non-identical twins in protein-protein interactions

In biology proteins from different structural classes interact across and within classes in ways that are optimized to achieve balanced functional outputs. The interactions between intrinsically disordered proteins (IDPs) and other proteins rely on changes in flexibility and this is seen as a strong determinant for their function. This has fostered the notion that IDP’s bind with low affinity but high specificity. Here we have analyzed available detailed thermodynamic data for protein-protein interactions to put to the test if the thermodynamic profiles of IDP interactions differ from those of other protein-protein interactions. We find that ordered proteins and the disordered ones act as non identical twins operating by similar principles but where the disordered proteins complexes are on average less stable by 2.5 kcal mol-1

Patient-assessed short-term positive response to cardiac resynchronization therapy is an independent predictor of long-term mortality.

Cardiac resynchronization therapy (CRT) has a well-documented positive effect on mortality and heart failure morbidity. The aim of this study was to assess the long-term survival and the predictive value of self-assessed functional status on the long-term prognosis of patients treated with CRT-pacemaker (CRT-P).METHODS AND RESULTS: Data were retrospectively collected from medical records of 446 consecutive patients implanted with CRT-P at a large-volume Swedish tertiary care centre. Primary outcome was all-cause mortality, predictive variables were assessed by log-rank test and univariate cox regression. Three hundred and nine patients had reliable information available on early improvement after implantation and were included in the multivariate analyses. The cohort was followed for a median of 79 months and was similar in baseline characteristics compared with major controlled trials. During follow-up 204 patients died, yearly mortality was 11.7%. Early improvement of self-assessed functional status was a strong independent predictor of survival [hazard ratio, HR 0.59, confidence interval (CI) 0.40-0.87, P = 0.007], together with well-known predictors; NYHA III-IV vs I-II (HR 1.66, CI 1.09-2.536, P = 0.018), age (HR 1.05, CI 1.03-1.08, P < 0.001), male gender (HR 2.0, CI 1.11-3.45, P = 0.021), and loop diuretic use (HR 4.41, CI 1.08-18.02). Patients with early improvement of self-assessed functional status had better 2-year and 5-year survival (P < 0.001).CONCLUSIONS: Real-life patient characteristics and predictors of outcome compare well with those in published prospective trials. Self-assessed functional status is a strong predictor of long-term survival, which may have implications for a more active follow-up of patients without spontaneous improvement

Mapping Flood Risk Uncertainty Zones in Support of Urban Resilience Planning

River flooding and urbanization are processes of different character that take place worldwide. As the latter tends to make the consequences of the former worse, together with the uncertainties related to future climate change and flood-risk modeling, there is a need to both use existing tools and develop new ones that help the management and planning of urban environments. In this article a prototype tool, based on estimated maximum land cover roughness variation, the slope of the ground, and the quality of the used digital elevation models, and that can produce flood ‘uncertainty zones’ of varying width around modeled flood boundaries, is presented. The concept of uncertainty, which urban planners often fail to consider in the spatial planning process, changes from something very difficult into an advantage in this way. Not only may these uncertainties be easier to understand by the urban planners, but the uncertainties may also function as a communication tool between the planners and other stakeholders. Because flood risk is something that urban planners always need to consider, these uncertainty zones can function both as buffer areas against floods, and as blue-green designs of significant importance for a variety of ecosystem services. As the Earth is warming and the world is urbanizing at rates and scales unprecedented in history, we believe that new tools for urban resilience planning are not only urgently needed, but also will have a positive impact on urban planning

Structure and dynamics of an archeal monoglyceride lipase from Palaeococcus ferrophilus as revealed by crystallography and in silico analysis

The crystallographic analysis of a lipase from Palaeococcus ferrophilus (PFL) previously annotated as a lysophospholipase revealed high structural conservation with other monoglyceride lipases, in particular in the lid domain and substrate binding pockets. In agreement with this observation, PFL was shown to be active on various monoacylglycerols. Molecular Dynamics (MD) studies performed in the absence and in the presence of ligands further allowed characterization of the dynamics of this system and led to a systematic closure of the lid compared to the crystal structure. However, the presence of ligands in the acyl-binding pocket stabilizes intermediate conformations compared to the crystal and totally closed structures. Several lid-stabilizing or closure elements were highlighted, i.e., hydrogen bonds between Ser117 and Ile204 or Asn142 and its facing amino acid lid residues, as well as Phe123. Thus, based on this complementary crystallographic and MD approach, we suggest that the crystal structure reported herein represents an open conformation, at least partially, of the PFL, which is likely stabilized by the ligand, and it brings to light several key structural features prone to participate in the closure of the lid