Asynchronous stigmergic sorting of binary matrix patterns: applications of classical distributed computing ideas

Multi-agent stigmergy forms the basis of explanatory theories for various self-organized biological phenomena, and also serves as an implementation strategy for several important artificial applications. While a number of sophisticated techniques have been used in the modeling and analysis of stigmergic processes, none of them, yet, seem to be drawn from the toolbox of classical distributed computing. Our goals are to investigate and lay the groundwork for the use of classical distributed computing ideas in reasoning about stigmergic computation. Specifically, we investigate case studies that are drawn from the domain of binary matrix pattern sorting. Here, a `swarm\u27 of memory-less and non-communicating agents follow a set of local stigmergic rules to asynchronously sort the binary states of cells in a 2-D grid so as to satisfy some global pattern specification. This domain is attractive as a test-bed because it serves as an abstraction for instances of biological pattern sorting and also because of its stigmergic expressiveness. We demonstrate the application of the following four distributed computing concepts: (1) execution serializability, (2) local checking, (3) variant functions, and (4) indistinguishability (the last as an impossibility proof technique) in the modeling and analysis of our case studies. Based on our preliminary experience with this particular domain, it seems to us that classical distributed computing techniques could be applied further in reasoning about stigmergic systems, perhaps leading to the formulation of a generalized stigmergic computational paradigm based on the principles of distributed computing

Executable Documentation of Template-Hook Interactions in Frameworks using JML

Object-oriented frameworks are an important technique for capturing design expertise. However, the learning curve for a framework is usually quite steep and can be the biggest obstacle in its adoption. We propose an executable and yet readable method for framework documentation using the Java Modelling Language (JML), based on the specification of the interaction between a framework\u27s template methods and its customizable hooks. This method is geared toward allowing the developers to quickly instantiate a prototype application from the framework, which can be later tweaked using some other detailed and usually non-executable documentation. We use flow-based assertions to specify the hook method preconditions and template method postconditions. The flow-based precondition for a particular hook serves as a modular documentation of when and how that hook is called in the framework\u27s overall call-sequence. Similarly, the flow-based postcondition of a template method tells the possible sequences of hook invocations that its execution may cause. Flow-based assertions are written using a few types, which we precisely specify. We also briefly describe a case study that uses our technique to document a Model-View-Controller framework

Record of Early to Middle Eocene paleoenvironmental changes from lignite mines, western India

Various Eocene hyperthermal events have been recorded from lignite sections of western India in the past decade. To infer the paleoenvironment, during a warm paleotropical climate of India, we have assessed multiple microfossil groups like pollen/spores, dinoflagellates and foraminifera from Early Eocene lignite mine sections from the Cambay (Surkha) and Barmer (Giral) basins and Middle Eocene sections from the Kutch Basin (Matanomadh and Panandhro mines) of western India. The Surkha and Giral sections exhibit a dominance of rainforest elements (Arengapollenites achinatus, Longapertites retipilatus), thermophilic mangrove palm Nypa and (sub)tropical dinoflagellate cyst Apectodinium, Cordosphaeridium and Kenleyia. This palynomorph assemblage is indicative of a marginal marine setting within a hot and humid climate. During the Middle Eocene, the diversity of dinocyst assemblage increased and a decrease in percentage of mangrove elements was observed in the Matanomadh and Panandhro mine sections of the Kutch Basin as compared to the Early Eocene sections of western India. Bloom of triserial planktic (Jenkinsina columbiana) and rectilinear benthic (Brizalina sp., Trifarina advena rajasthanensis) foraminifera indicates eutrophic conditions of deposition during the Late Lutetian–Early Bartonian in the lignite sections of the Kutch Basin which later changed to oligotrophic, open marine conditions towards the Bartonian (planktic E12 zone). This change to oligotrophic conditions coincides with a drastic increase in diversity of planktic foraminifera in the top portion of lignite mines of the Kutch Basin which may be correlated with the Kirthar–Wilson Bluff transgression event in the Bartonian observed across basins in India, Pakistan and Australia potentially linked to sea level rise around the Middle Eocene Climatic Optimum.</p

Cardiovascular risk factors from diagnosis in children with type 1 diabetes mellitus: a longitudinal cohort study

BACKGROUND: For childhood onset type 1 diabetes (T1D), the pathogenesis of atherosclerosis is greatly accelerated and results in early cardiovascular disease (CVD) and increased mortality. However, cardioprotective interventions in this age group are not routinely undertaken. AIMS: To document prevalence of cardiovascular risk factors from diagnosis of childhood T1D and their relationship with disease duration and ethnicity. METHODS: Routinely collected clinical records for 565 children with T1D were retrospectively analyzed. Data were collected from diagnosis and at routine check-ups at pediatric diabetes clinics across Barts Health National Health Service Trust. Age at diagnosis was 8.5 years (0.9–19.4). Mean follow-up 4.3 years (0–10.8). 48% were boys and 60% were non-white. Linear longitudinal mixed effects models were used to evaluate relationships between risk factors and diabetes duration. RESULTS: CVD risk factors were present at first screening; 33.8% of children were overweight or obese, 20.5% were hypertensive (elevated diastolic blood pressure (BP)) and total cholesterol, low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol were abnormal in 63.5%, 34.2% and 22.0%, respectively. Significant associations between diabetes duration and annual increases of body mass index (0.6 kg/m2), BP (0.1 SD score) and lipids (0.02–0.06 mmol/L) were noted. Annual increases were significantly higher in black children for BP and Bangladeshi children for lipids. Bangladeshi children also had greatest baseline levels. CONCLUSIONS: CVD risk factors are present in up to 60% of children at diagnosis of T1D and increase in prevalence during the early years of the disease. Commencing screening in younger children and prioritizing appropriate advice and attention to ethnic variation when calculating risk should be considered

Short communication: The effect of depth of operation and soaking time on catch rates in the experimental tuna longline fisheries in Lakshadweep Sea, India

Most of the marine fish landings from the Indian waters are from the fishing operations in the coastal shelf area, especially from the shallower region ranging from 5 to 100 m depth. Heavy demand for seafood in domestic and international markets underlines the need for increasing the marine fish production. Catch trends indicated that the production from the coastal fisheries is almost stagnant and point towards the need for harvesting unexploited or under exploited oceanic fish resources. Present fleet size of the distant water fishing vessels is very less in spite of India’s vast EEZ of 2.02 million sq km and two Islands groups, viz., Andaman, Nicobar and Lakshadweep. ... Experimental longline operations were initiated in the Lakshadweep Sea to tap the unexploited oceanic tuna fishes. This paper discusses the effect of depth of operation and soaking time on the overall catching performance and species selectivity in the longlines operated

Complex Contact-Based Dynamics of Microsphere Monolayers Revealed by Resonant Attenuation of Surface Acoustic Waves

Contact-based vibrations play an essential role in the dynamics of granular materials. Significant insights into vibrational granular dynamics have previously been obtained with reduced-dimensional systems containing macroscale particles. We study contact-based vibrations of a two-dimensional monolayer of micron-sized spheres on a solid substrate that forms a microscale granular crystal. Measurements of the resonant attenuation of laser-generated surface acoustic waves reveal three collective vibrational modes that involve displacements and rotations of the microspheres, as well as interparticle and particle-substrate interactions. To identify the modes, we tune the interparticle stiffness, which shifts the frequency of the horizontal-rotational resonances while leaving the vertical resonance unaffected. From the measured contact resonance frequencies we determine both particle-substrate and interparticle contact stiffnesses and find that the former is an order of magnitude larger than the latter. This study paves the way for investigating complex contact-based dynamics of microscale granular crystals and yields a new approach to studying micro- to nanoscale contact mechanics in multiparticle networks.National Science Foundation (U.S.) (Grant CMMI-1333858)United States. Army Research Office (Grant W911NF-15-1-0030)University of Washington. Royalty Research FoundationNational Science Foundation (U.S.) (Grant CHE-1111557

Diamagnetic susceptibility of lead ion

This article does not have an abstract

Validating First-Principles Phonon Lifetimes via Inelastic Neutron Scattering

Phonon lifetimes are a key component of quasiparticle theories of transport, yet first-principles lifetimes are rarely directly compared to inelastic neutron scattering (INS) results. Existing comparisons show discrepancies even at temperatures where perturbation theory is expected to be reliable. In this work, we demonstrate that the reciprocal space voxel ($q$-voxel), which is the finite region in reciprocal space required in INS data analysis, must be explicitly accounted for within theory in order to draw a meaningful comparison. We demonstrate accurate predictions of peak widths of the scattering function when accounting for the $q$-voxel in CaF$_2$ and ThO$_2$. Passing this test implies high fidelity of the phonon interactions and the approximations used to compute the Green's function, serving as critical benchmark of theory, and indicating that other material properties should be accurately predicted; which we demonstrate for thermal conductivity

High Precision Femtosecond Laser Ablation ICP‐MS Measurement of Benthic Foraminiferal Mn‐Incorporation for Paleoenvironmental Reconstruction: A Case Study From the Plio‐Pleistocene Caribbean Sea

Closure of the Central American Seaway (CAS) and hydrology of the Caribbean Sea triggered Northern Hemisphere Glaciation and played an important role in the Pliocene to modern-day climate re-establishing the deep and surface ocean currents. New data on Mn/Ca obtained with femtosecond laser ablation inductively coupled plasma mass spectrometry on well-preserved tests of the epibenthic foraminifer Cibicidoides wuellerstorfi and infaunal C. mundulus contribute to the interpretation of paleoenvironmental conditions of the Caribbean Sea between 5.2 and 2.2 Ma (million years) across the closure of the CAS. Hydrothermal activity at the Lesser Antilles may be a primary source of Mn in the well-oxygenated Plio-Pleistocene Caribbean Sea. Incorporation of Mn in the benthic foraminifer shell carbonate is assumed to be affected by surface ocean nutrient cycling, and may hence be an indicator of paleoproductivity. Key Points - Femtosecond-laser ablation inductively coupled plasma mass spectrometry provides a new approach on distinguishing Mn of the ontogenetic shell calcite from Mn of the authigenic coatings - Ontogenetic Mn within the foraminifer shell calcite may result from the regional nutrient cycle - Mn in the deep eastern Caribbean Sea may mainly derive from hydrothermal sources along the Antilles Island Ar