scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Phd by thesis

01 Apr 1988-Nature (Nature Publishing Group)-Vol. 332, Iss: 6166, pp 676-676
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI
TL;DR: This work contextualizes research done on Grapevine leafroll-associated virus 3 within an ecological framework that forms the backbone of the discussion regarding current and potential GLD management strategies, and introduces various aspects of GLD biology and ecology.
Abstract: Grapevine leafroll disease (GLD) is caused by a complex of vector-borne virus species in the family Closteroviridae. GLD is present in all grape-growing regions of the world, primarily affecting wine grape varieties. The disease has emerged in the last two decades as one of the major factors affecting grape fruit quality, leading to research efforts aimed at reducing its economic impact. Most research has focused on the pathogens themselves, such as improved detection protocols, with limited work directed towards disease ecology and the development of management practices. Here we discuss the ecology and management of GLD, focusing primarily on Grapevine leafroll-associated virus 3, the most important virus species within the complex. We contextualize research done on this system within an ecological framework that forms the backbone of the discussion regarding current and potential GLD management strategies. To reach this goal, we introduce various aspects of GLD biology and ecology, followed by disease management case studies from four different countries and continents (South Africa, New Zealand, California-USA, and France). We review ongoing regional efforts that serve as models for improved strategies to control this economically important and worldwide disease, highlighting scientific gaps that must be filled for the development of knowledge-based sustainable GLD management practices.

157 citations

Proceedings Article
25 Jul 2015
TL;DR: This paper identifies a few core aspects of the CoBots underlying their robust functionality, and presents sampled results from a deployment and concludes with a brief review of other features of the service robots.
Abstract: We research and develop autonomous mobile service robots as Collaborative Robots, i.e., CoBots. For the last three years, our four CoBots have autonomously navigated in our multi-floor office buildings for more than 1,000km, as the result of the integration of multiple perceptual, cognitive, and actuations representations and algorithms. In this paper, we identify a few core aspects of our CoBots underlying their robust functionality. The reliable mobility in the varying indoor environments comes from a novel episodic non-Markov localization. Service tasks requested by users are the input to a scheduler that can consider different types of constraints, including transfers among multiple robots. With symbiotic autonomy, the CoBots proactively seek external sources of help to fill-in for their inevitable occasional limitations. We present sampled results from a deployment and conclude with a brief review of other features of our service robots.

157 citations


Cites background or methods from "Phd by thesis"

  • ...The fact that our research goal includes the persistent deployment of the CoBots led to the introduction of novel mapping, sensing, and localization approaches [Biswas, 2014]....

    [...]

  • ...Episodic non-Markov Localization has been deployed on all the CoBots over part of a 1,000km Challenge [Biswas, 2014], and has been used to localize the robots in many different environments spanning multiple floors across multiple buildings....

    [...]

  • ...Given the classifications, and the form of the observation likelihoods of the LTFs and STFs, episodic non-Markov localization solves for the maximum likelihood estimate of the belief by representing the Belief as a cost function and optimizing over it, instead of keeping multiple estimates represented as a particle filter [Biswas, 2014]....

    [...]

Journal ArticleDOI
TL;DR: A large class of continuous time multifractal random measures and processes with arbitrary log infinitely divisible exact or asymptotic scaling law with main statistical properties is defined and the stochastic convergence of the defined processes is proved.
Abstract: We define a large class of continuous time multifractal random measures and processes with arbitrary log infinitely divisible exact or asymptotic scaling law. These processes generalize within a unified framework both the recently defined log-normal multifractal random walk [J.F. Muzy, J. Delour, and E. Bacry, Eur. J. Phys. B $17,$ 537 (2000), E. Bacry, J. Delour, and J.F. Muzy, Phys. Rev. E $64,$ 026103 (2001)] and the log-Poisson ``product of cylindrical pulses'' [J. Barral and B.B. Mandelbrot, Cowles Foundation Discussion Paper No. 1287, 2001 (unpublished)]. Our construction is based on some ``continuous stochastic multiplication'' [as introduced in F. Schmitt and D. Marsan, Eur. J. Phys. B. $20,$ 3 (2001)] from coarse to fine scales that can be seen as a continuous interpolation of discrete multiplicative cascades. We prove the stochastic convergence of the defined processes and study their main statistical properties. The question of genericity (universality) of limit multifractal processes is addressed within this new framework. We finally provide a method for numerical simulations and discuss some specific examples.

157 citations


Cites background from "Phd by thesis"

  • ...In a recent works, Pinton and his collaborators [37, 38] studied the intermittency of Lagrangian trajectories and related it to the slow (logarithmic) decay of the particle acceleration correlations [38, 40], very much like for a MRW model....

    [...]

  • ...This was possible because two groups developed new experimental devices based on a fast imaging system [36] or ultrasound techniques [37, 38] allowing for a direct measurement of the velocity of a single tracer in a turbulent flow....

    [...]

Journal ArticleDOI
TL;DR: The study shows that the spatially extended model has not only more complex dynamic patterns in the space, but also chaos and spiral waves, which may help to better understand the dynamics of an aquatic community in a real marine environment.
Abstract: In this paper, we investigate the emergence of a ratio-dependent predator-prey system with MichaelisMenten–type functional response and reaction diffusion. We obtain the conditions of Hopf, Turing, and wave bifurcation in a spatial domain. Furthermore, we present a theoretical analysis of evolutionary processes that involves organisms distribution and their interaction of spatially distributed population with local diffusion. The results of numerical simulations reveal that the typical dynamics of population density variation is the formation of isolated groups, i.e., stripelike or spotted or coexistence of both. Our study shows that the spatially extended model has not only more complex dynamic patterns in the space, but also chaos and spiral waves. It may help us better understand the dynamics of an aquatic community in a real marine environment.

157 citations


Cites background from "Phd by thesis"

  • ...Predator-prey models follow two general principles: one is that population dynamics can be decomposed into birth and death processes; the other is the conservation of mass princ iple, stating that predators can grow only as a function of wha t they have eaten [9]....

    [...]

  • ...In this caseμx(x) can be neglected and set to 0 (as long as the predator exists) [9]....

    [...]

Journal ArticleDOI
TL;DR: The aim of the present work was to study the fundamental mechanism of oxidant release by macrophages at the level of a single cell, in real time and quantitatively, and to calculate the calculation of time variations of emission flux for each species and the reconstruction of the original flux of production of primary species, O2.− and NO.
Abstract: Macrophages are key cells of the immune system. During phagocytosis, the macrophage engulfs a foreign bacterium, virus, or particle into a vacuole, the phagosome, wherein oxidants are produced to neutralize and decompose the threatening element. These oxidants derive from in situ production of superoxide and nitric oxide by specific enzymes. However, the chemical nature and sequence of release of these compounds is far from being completely determined. The aim of the present work was to study the fundamental mechanism of oxidant release by macrophages at the level of a single cell, in real time and quantitatively. The tip of a microelectrode was positioned at a micrometric distance from a macrophage in a culture to measure oxidative-burst release by the cell when it was submitted to physical stimulation. The ensuing release of electroactive reactive oxygen and nitrogen species was detected by amperometry and the exact nature of the compounds was characterized through comparison with in vitro electrochemical oxidation of H2O2, ONOO-, NO*, and NO2(-) solutions. These results enabled the calculation of time variations of emission flux for each species and the reconstruction of the original flux of production of primary species, O2*- and NO*, by the macrophage.

156 citations


Cites background from "Phd by thesis"

  • ...the addition of the oxidation currents from each species as determined from independent solutions of each species.([44]) Based on the result of these fine measurements, a faster and...

    [...]

References
More filters
Journal ArticleDOI
TL;DR: A new family of highly fluorescent indicators has been synthesized for biochemical studies of the physiological role of cytosolic free Ca2+ using an 8-coordinate tetracarboxylate chelating site with stilbene chromophores that offer up to 30-fold brighter fluorescence.

21,582 citations


"Phd by thesis" refers background in this paper

  • ...members of this group were produced by Tsien and colleagues [1, 10, 11]....

    [...]

  • ...The introduction of Ca 2+ -sensitive fluorescent dyes more than twenty years ago and their permanent improvement [10] enabled investigators to gain unprecedented insights into the mechanisms of cellular signalling....

    [...]

ReportDOI
01 Nov 1990
TL;DR: This report will establish methods for performing a domain analysis and describe the products of the domain analysis process to illustrate the application of domain analysis to a representative class of software systems.
Abstract: : Successful Software reuse requires the systematic discovery and exploitation of commonality across related software systems. By examining related software systems and the underlying theory of the class of systems they represent, domain analysis can provide a generic description of the requirements of that class of systems and a set of approaches for their implementation. This report will establish methods for performing a domain analysis and describe the products of the domain analysis process. To illustrate the application of domain analysis to a representative class of software systems, this report will provide a domain analysis of window management system software.

4,420 citations

Journal ArticleDOI
TL;DR: The straw person model (SPM) as mentioned in this paper has been proposed to explain the orientation effects of active galactic nuclei (AGN) and quasars in the line of sight (LOS) images.
Abstract: Because the critical central regions of Active Galactic Nuclei (AGN) and quasars are strongly nonspherical but spatially unresolved, orientation effects have been the source of much confusion. In fact, it now appears that much of the variety in AGN types is just the result of varying orientation relative to the line of sight. We can define an extreme hypothesis,, the straw person model (SPM), in which there are two basic types of AGN: the radio quiets and the radio louds. For each type there is a range in intrinsic luminosity, and the luminosity controls some properties such as the Fanaroff and Riley classes. However, at a given intrinsic luminosity, all other properties such as spectroscopic classification and VLBI component speeds are ascribed to orientation. This model is only a caricature of the unification idea, and is already ruled out on many grounds, but it will be useful for organizing the discussion. I’ll describe what I consider to be convincing evidence that orientation effects are important and widespread. The true situation may be in some sense half way between the SPM and the hypothesis that orientation doesn’t affect classification at aIl. To us optimists, the orienration cup is half full rather than half empty. Although it is too soon to say for sure, the hypothesis that most objects’ classifications would be different if seen from other directions is a tenable one today.

4,005 citations

Journal ArticleDOI
TL;DR: This Review assembles the current knowledge on the isolation of microfibrillated cellulose from wood and its application in nanocomposites; the preparation of nanocrystalline cellulose and its use as a reinforcing agent; and the biofabrication of bacterial nanocellulose, as well as its evaluation as a biomaterial for medical implants.
Abstract: Cellulose fibrils with widths in the nanometer range are nature-based materials with unique and potentially useful features. Most importantly, these novel nanocelluloses open up the strongly expanding fields of sustainable materials and nanocomposites, as well as medical and life-science devices, to the natural polymer cellulose. The nanodimensions of the structural elements result in a high surface area and hence the powerful interaction of these celluloses with surrounding species, such as water, organic and polymeric compounds, nanoparticles, and living cells. This Review assembles the current knowledge on the isolation of microfibrillated cellulose from wood and its application in nanocomposites; the preparation of nanocrystalline cellulose and its use as a reinforcing agent; and the biofabrication of bacterial nanocellulose, as well as its evaluation as a biomaterial for medical implants.

3,452 citations

Journal ArticleDOI
TL;DR: The solid electrolyte interphase (SEI) is a protecting layer formed on the negative electrode of Li-ion batteries as a result of electrolyte decomposition, mainly during the first cycle as discussed by the authors.

2,386 citations