Activity centred analysis and design in the evolution of learning networks

This paper provides an overview of, and rationale for, an approach to analysing complex learning networks. The approach involves a strong commitment to providing knowledge which is useful for design and it gives a prime place to the activity of those involved in networked learning. Hence the framework that we are offering is known as “Activity Centred Analysis and Design” or ACAD for short. We have used the ACAD framework in the analysis of 20 or so learning networks. These networks have varied in purpose, scale and complexity and the experience we have gained in trying to understand how these networks function has helped us improve the ACAD framework. This paper shares some of the outcomes of that experience and describes some significant new refinements to how we understand the framework. While the framework is able to deal with a very wide range of learning situations, in this paper we look more closely at some issues which are of particular importance in networked learning. For example, we discuss the distributed nature of design in networked learning – acknowledging the fact that learning networks are almost invariably co-configured by everyone who participates in them, and that this aspect of participation is often explicitly valued and encouraged. We see participation in (re)design as a challenging activity: one that benefits from some structured methods and ways of representing and unpicking the tangles of tasks, activities, tools, places and people

Bleaching of sol-gel glass film with embedded gold nanoparticles by thermal poling

Gold clusters embedded in glass are expected to be hard to dissolve in the form of ions since gold is essentially a nonreactive metal. In spite of that, bleaching of Au-doped nanocomposite sol-gel glass film on a soda-lime glass substrate is demonstrated in which electric-field thermal poling is employed to effectively dissolve randomly distributed gold nanoparticles (15 nm in diameter) embedded in a low conductivity sol-gel glass film with a volume filling factor as small as 2.3%. The surface plasmon absorption band at 520 nm is suppressed in the region covered by the anodic electrode. The phenomenon is explained by the ionization of the gold nanoparticles and the redistribution of gold ions in the glass matrix due to the action of the extremely high electrostatic field locally developed during poling

Complex Box Splines

The novel concept of box spline of complex degree is introduced and several of its properties derived and discussed. These box splines of complex degree generalize and extend the classical box splines. Relations to a class of fractional derivatives defined on certain function spaces are also exhibited

Third-order nonlinear optical properties of bismuth-borate glasses measured by conventional and thermally managed eclipse Z scan

Third-order nonlinearity one order of magnitude larger than silica is measured in bismuth-borate glasses presenting a fast response (<200 fs). The results for the sign and magnitude of the nonlinearity were obtained using a combination of the eclipse Z scan with thermal nonlinearity managed Z scan, whereas the Kerr shutter technique was employed to obtain the electronic time response of the nonlinearity, all performed with 76 MHz repetition rate 150 fs pulses at 800 nm. Conventional Z scans in the picosecond regime at 532 and 1064 nm were also independently performed, yielding the values of the third-order nonlinear susceptibilities at those wavelengths. The results obtained for the femtosecond response, enhanced third-order nonlinearity of this glass (with respect to silica), place this glass system as an important tool in the development of photonics devices. Electro-optical modulators, optical switches, and frequency converters are some of the applications using second-order nonlinear properties of the Bi-glass based on the rectification model

Recovery technologies for materials in landfills

Europe hosts more than 500,000 landfills of which 90% are non-sanitary and around 80% essentially contain Urban Solid Waste (https://www.eurelco.org/infographic). Urban landfills (UL) and extractive (mining and metallurgical) industry residues (EIR) are potential sources of materials that, if recovered, can contribute to the circularity of economy. Among other factors, technology plays one essential role in the viability of landfill mining projects (Krook, et al, 2012). The methods for mapping landfills, sampling and characterizing waste, the readiness of technologies, the optimization of technologies and their combination in treatment and recovery schemes, their applicability, costs and environmental impacts effect the valorization of waste from landfills. This report addresses Deliverable 1.1 “Recovery technologies for materials in landfills” developed by Working Group 2 of COST Action “Mining the European Anthroposphere” (MINEA). MINEA aims to quantify and assess the material resources and reserves in the Anthroposphere and consolidate existing knowledge related to the exploration, evaluation, classification and recovery of materials in anthropogenic deposits and waste flows. This report integrates the activities of the MINEA WG2 in the 1st Grant Period (May 2016 to April 2017). The following documents were developed: (1) Literature Review Report on practices and technologies for waste valorization from landfills (Calvo, 2016) and (2) MINEA WG2 Workshop on technologies in the landfill-mining sector, which resulted in an overview on landfill mining projects and on state-of-the-art as well as enhanced recovery technologies (Workshop on “Technologies for material recovery from landfills and mining residues”, Book of abstracts, 2016). This report also profits from the non published report on “Science and technology in enhanced landfill mining” (EURELCO, 2016), which has been developed by the Working Group II of the European Enhanced Landfill Mining Consortium (EURELCO). Both activities examine current practices, knowledge transfer and recovery technologies across European countries, research fields and disciplines. This information is essential to assess the availability of secondary material from landfills and the viability of landfill mining projects in the context of circular economy

Photochemical studies of cis-[Ru(bpy)2(4-bzpy)(CO)](PF6)2 and cis-[Ru(bpy)2(4-bzpy)(Cl)](PF6): Blue light-induced nucleobase binding.

The ruthenium(II) compounds cis-[Ru(bpy)2(4-bzpy)(CO)](PF6)2 (I) and cis-[Ru(bpy)2(4-bzpy)(Cl)](PF6) (II) (4-bzpy=4-benzoylpyridine, bpy=2,2'-bipyridine) were synthesized and characterized by spectroscopic and electrochemical techniques. The crystal structure of II was determined by X-ray diffraction. The photochemical behavior of I in aqueous solution shows that irradiation with ultraviolet light (365nm) releases both CO and 4-bzpy leading to the formation of the cis-[Ru(bpy)2(H2O)2]2+ ion as identified by NMR and electronic spectroscopy. Carbon monoxide release was confirmed with the myoglobin method and by gas chromatographic analysis of the headspace. CO release was not observed when aqueous I was irradiated with blue light (453nm). Changes in the electronic and 1H NMR spectra indicate that I undergoes photoaquation of 4-bzpy to form cis-[Ru(bpy)2(CO)(H2O)]2+. Blue light irradiation of aqueous II released the coordinated 4-bzpy to give the cis-[Ru(bpy)2(H2O)(Cl)]2+ ion. When the latter reaction was carried out in the presence of the nucleobase guanine, Ru-guanine adducts were formed, indicating that the metal containing photoproduct may also participate in biologically relevant reactions. The photochemical behavior of I indicates that it can release either CO or 4-bzpy depending on the wavelength chosen, a feature that may have therapeutic application

A Disease Register for ME/CFS: Report of a Pilot Study.

BACKGROUND: The ME/CFS Disease Register is one of six subprojects within the National ME/CFS Observatory, a research programme funded by the Big Lottery Fund and sponsored by Action for ME. A pilot study in East Anglia, East Yorkshire, and London aimed to address the problem of identifying representative groups of subjects for research, in order to be able to draw conclusions applicable to the whole ME/CFS population.While not aiming for comprehensive population coverage, this pilot register sought to recruit participants with ME/CFS in an unbiased way from a large population base. Those recruited are constituting a cohort for long-term follow-up to shed light on prognosis, and a sampling frame for other studies. FINDINGS: Patients with unidentified chronic fatigue were identified in GP databases using a READ-code based algorithm, and conformity to certain case definitions for ME/CFS determined. 29 practices, covering a population aged 18 to 64 of 143,153, participated.510 patients with unexplained chronic fatigue were identified. 265 of these conformed to one or more case definitions. 216 were invited to join the register; 160 agreed. 96.9% of participants conformed to the CDC 1994 (Fukuda) definition; the Canadian definition defined more precisely a subset of these. The addition of an epidemiological case definition increased case ascertainment by approximately 4%. A small-scale study in a specialist referral service in East Anglia was also undertaken.There was little difference in pattern of conformity to case definitions, age or sex among disease register participants compared with subjects in a parallel epidemiological study who declined to participate.One-year follow-up of 50 subjects showed little change in pain or fatigue scores. There were some changes in conformity to case definitions. CONCLUSIONS: Objective evaluation indicated that the aim of recruiting participants with ME/CFS to a Disease Register had been fulfilled, and confirmed the feasibility of our approach to case identification, data processing, transmission, storage, and analysis. Future developments should include expansion of the ME/CFS Register and its linkage to a tissue sample bank and post mortem tissue archive, to facilitate support for further research studies

Robust signatures in the current-voltage characteristics of DNA molecules oriented between two graphene nanoribbon electrodes

In this work we numerically calculate the electric current through three kinds of DNA sequences (telomeric, \lambda-DNA, and p53-DNA) described by different heuristic models. A bias voltage is applied between two zig-zag edged graphene contacts attached to the DNA segments, while a gate terminal modulates the conductance of the molecule. The calculation of current is performed by integrating the transmission function (calculated using the lattice Green's function) over the range of energies allowed by the chemical potentials. We show that a telomeric DNA sequence, when treated as a quantum wire in the fully coherent low-temperature regime, works as an excellent semiconductor. Clear steps are apparent in the current-voltage curves of telomeric sequences and are present independent of lengths and sequence initialisation at the contacts. The current-voltage curves suggest the existence of stepped structures independent of length and sequencing initialisation at the contacts. We also find that the molecule-electrode coupling can drastically influence the magnitude of the current. The difference between telomeric DNA and other DNA, such as \lambda-DNA and DNA for the tumour suppressor p53, is particularly visible in the length dependence of the current