Personalised trails and learner profiling within e-learning environments

This deliverable focuses on personalisation and personalised trails. We begin by introducing and defining the concepts of personalisation and personalised trails. Personalisation requires that a user profile be stored, and so we assess currently available standard profile schemas and discuss the requirements for a profile to support personalised learning. We then review techniques for providing personalisation and some systems that implement these techniques, and discuss some of the issues around evaluating personalisation systems. We look especially at the use of learning and cognitive styles to support personalised learning, and also consider personalisation in the field of mobile learning, which has a slightly different take on the subject, and in commercially available systems, where personalisation support is found to currently be only at quite a low level. We conclude with a summary of the lessons to be learned from our review of personalisation and personalised trails

A catalog of visual double and multiple stars with eclipsing components

A new catalog of visual double systems containing eclipsing binaries as one component is presented. The main purpose of this catalog is to compile a complete list of all known multiples of this variety, both for current analysis and to highlight those in need of additional observations. All available photometric and astrometric data were analyzed, resulting in new orbits for eight systems and new times of minimum light for a number of the eclipsing binaries. Some of the systems in the catalog have acceptable solutions for their visual orbits, although in most cases their orbital periods are too long for simultaneous analysis. Also included, however, are a number of systems which currently lack an orbital solution but which may be suitable for simultaneous analysis in the future.Comment: 15 pages, 8 figures, 4 tables, published in A

The potential risks and impact of the start of the 2015–2016 influenza season in the WHO European Region: a rapid risk assessment

Background: Countries in the World Health Organization (WHO) European Region are reporting more severe influenza activity in the 2015–2016 season compared to previous seasons. Objectives: To conduct a rapid risk assessment to provide interim information on the severity of the current influenza season. Methods: Using the WHO manual for rapid risk assessment of acute public health events and surveillance data available from Flu News Europe, an assessment of the current influenza season from 28 September 2015 (week 40/2015) up to 31 January 2016 (week 04/2016) was made compared with the four previous seasons. Results: The current influenza season started around week 51/2015 with higher influenza activity reported in Eastern Europe compared to Western Europe. There is a strong predominance of influenza A(H1N1)pdm09 compared to previous seasons, but the virus is antigenically similar to the strain included in the seasonal influenza vaccine. Compared to the 2014/2015 season, there was a rapid increase in the number of severe cases in Eastern European countries with the majority of such cases occurring among adults aged < 65 years. Conclusions: The current influenza season is characterized by an early start in Eastern European countries, with indications of a more severe season. Currently circulating influenza A(H1N1)pdm09 viruses are antigenically similar to those included in the seasonal influenza vaccine, and the vaccine is expected to be effective. Authorities should provide information to the public and health providers about the current influenza season, recommendations for the treatment of severe disease and effective public health measures to prevent influenza transmission

Development and Assessment of a Pooled Serum as Candidate Standard to Measure Influenza A Virus Group 1 Hemagglutinin Stalk-Reactive Antibodies

The stalk domain of the hemagglutinin has been identified as a target for induction of protective antibody responses due to its high degree of conservation among numerous influenza subtypes and strains. However, current assays to measure stalk-based immunity are not standardized. Hence, harmonization of assay readouts would help to compare experiments conducted in different laboratories and increase confidence in results. Here, serum samples from healthy individuals (n = 110) were screened using a chimeric cH6/1 hemagglutinin enzyme-linked immunosorbent assay (ELISA) that measures stalk-reactive antibodies. We identified samples with moderate to high IgG anti-stalk antibody levels. Likewise, screening of the samples using the mini-hemagglutinin (HA) headless construct #4900 and analysis of the correlation between the two assays confirmed the presence and specificity of anti-stalk antibodies. Additionally, samples were characterized by a cH6/1N5 virus-based neutralization assay, an antibody-dependent cell-mediated cytotoxicity (ADCC) assay, and competition ELISAs, using the stalk-reactive monoclonal antibodies KB2 (mouse) and CR9114 (human). A “pooled serum” (PS) consisting of a mixture of selected serum samples was generated. The PS exhibited high levels of stalk-reactive antibodies, had a cH6/1N5-based neutralization titer of 320, and contained high levels of stalk-specific antibodies with ADCC activity. The PS, along with blinded samples of varying anti-stalk antibody titers, was distributed to multiple collaborators worldwide in a pilot collaborative study. The samples were subjected to different assays available in the different laboratories, to measure either binding or functional properties of the stalk-reactive antibodies contained in the serum. Results from binding and neutralization assays were analyzed to determine whether use of the PS as a standard could lead to better agreement between laboratories. The work presented here points the way towards the development of a serum standard for antibodies to the HA stalk domain of phylogenetic group 1

Immunogenicity and efficacy of one and two doses of Ad26.COV2.S COVID vaccine in adult and aged NHP

Safe and effective coronavirus disease-19 (COVID-19) vaccines are urgently needed to control the ongoing pandemic. While single-dose vaccine regimens would provide multiple advantages, two doses may improve the magnitude and durability of immunity and protective efficacy. We assessed one-and two-dose regimens of the Ad26.COV2.S vaccine candidate in adult and aged nonhuman primates (NHPs). A two-dose Ad26.COV2.S regimen induced higher peak binding and neutralizing antibody responses compared with a single dose. In one-dose regimens, neutralizing antibody responses were stable for at least 14 wk, providing an early indication of durability. Ad26.COV2.S induced humoral immunity and T helper cell (Th cell) 1-skewed cellular responses in aged NHPs that were comparable to those in adult animals. Aged Ad26.COV2.S-vaccinated animals challenged 3 mo after dose 1 with a SARS-CoV-2 spike G614 variant showed near complete lower and substantial upper respiratory tract protection for both regimens. Neutralization of variants of concern by NHP sera was reduced for B.1.351 lineages while maintained for the B.1.1.7 lineage independent of Ad26.COV2.S vaccine regimen.Molecular basis of virus replication, viral pathogenesis and antiviral strategie

Carbocationic Copolymerization in the Presence of Electron Pair Donors. 1. Copolymerization of Isobutylene and Isoprene with the Cumyl Acetate/boron Trichloride Initiating System

See Lin

Living Carbocationic Polymerization Xiv: Living Polymerization of Isobutylene with Ester.Ticl4 Complexes

The living polymerization of isobutylene (IB) has been induced by cumyl acetate·TiCl4 and cumyl propionate·TiCl4 complexes in CH2Cl2/n-C6H14 and CH3Cl/n-C6 H14 mixtures under conventional laboratory conditions at −40°C. The living nature of the polymerization was demonstrated by linear M̄n versus Wp (g PIB formed) plots starting at the origin. DPn obeys [IB]/[cumyl acetate·TiCl4] and molecular weight distributions (MWD) are very narrow, M̄w/M̄n = 1.05–1.13. PIBs having M̄n \u3e40000 have been prepared. The effects of the nature of the solvent, solvent composition, nature of the ester, ester/TiCl4 ratio and concentrations on rates, M̄ns and MWDs have been investigated. The living polymerization is faster by the cumyl acetate-TiCl4 than by the cumyl propionate·TiCl4 complex. The rate of living polymerizations is negligible at CuAc/TiCl4 = 1 and increases significantly in the presence of stoichiometric excess of TiCl4 over the ester. Undesirable initiation due to protogenic impurities can be suppressed by employing relatively nonpolar (hexane-rich) media, by increasing the ester/TiCl4, ratio, or by the addition of a non-initiating ester (ethyl acetate); however, the rates decrease as a consequence of these measures. Polymerizations induced by mixtures of cumyl acetate·TiCl4/cumyl propionate·TiCl4 complexes yield monomodal narrow MWDs indicating rapid ester exchange at the growing site which in turn suggests ionic active species. The kinetic findings are explained by a mechanistic scheme that rests on two propositions: Propagation involves activated (most probably ionized) polymer-ester·Lewis acid complexes, and free (uncomplexed) Lewis acid causes irreversible destruction of living propagation

New Transparent Flexible Uv-cured Films from Polyisobutylene-polyisoprene Block Polymers

Novel polyisobutylene-polyisoprene (PIB-PIP) multiblock polymers have been synthesized and used for the preparation of UV-cured transparent flexible coatings. The block polymers were tailor-made by bidirectional living carbocationic polymerization of isobutylene (IB) followed by sequential isoprene (IP) addition. PIB-PIP multiblocks containing highly cyclized tr-1,4-PIP sequences were mixed with a bisazide and photocrosslinked. Epoxidized PIB-PIP blocks were blended with a cationic photoinitiator and UV-cured. Blocks having 23 mol% total PIP content and PIB segments of M n = 16,600 and 18,800, respectively, gave transparent flexible coatings with 45 kg/cm2 tensile strength and 450% elongation. The coatings exhibited good adhesion to aluminum and are expected to have excellent barrier properties due to the presence of PIB sequences

New Thermoplastic Elastomers of Rubbery Polyisobutylene and Glassy Cyclopolyisoprene Segments

New thermoplastic elastomers (TPEs) consisting of a central rubbery polyisobutylene (PIB) and glassy outer cyclopolyisoprene (cy-PIP) segments have been prepared by living carbocationic polymerization by sequential monomer addition. First the homopolymerization of isobutylene (IB) and isoprene (IP) have been investigated. The living polymerization of isobutylene initiated by the p-dicumyl methoxy (p-DiCumOMe)/TiCl4 system in CH3Cl/n-C6H14 mixtures at −80°C gave living ⊕PIB⊕ dications of desired molecular weights. The polymerization of IP induced by cumyl acetate (CumOAc)/TiCl4 or cumyl methyl ether (CumOMe)/TiCl4 systems in the same solvent at −40°C readily yielded gel-free off-white powders comprising trans-1,4-PIP units and cy-PIP sequences. The polymerization most likely proceeds by trans-1,4-PIP ⊕ cations that undergo inter/intramolecular alkylation and cyclization leading to branched multiblocks. Block copolymers were synthesized by the addition of IP to charges containing ⊕PIB⊕ dications of different molecular weights. Under select conditions pure (tr-1,4-PIP)-b-PIB-b-(tr-1,4-PIP) triblocks with relatively short tr-1,4-PIP sequences have been obtained. Extended reaction times result in multiblocks; most likely ⊕ (tr-1,4-PIP)-b-PIB-b-(tr-1,4-PIP) ⊕ dications induce alkylation and cyclization of PIP sequences. The extent of alkylation can be regulated by the viscosity of the medium (molecular weight and/or concentration of the PIB midblock). The rate of IP incorporation decelerates after an initial fast polymerization; however, it can be accelerated by adding fresh Lewis acid to the system. Although tr-1,4-PIP endblocks of linear triblocks can be completely cyclized by acid treatment to saturated products, multiblocks cannot, probably because of their branched structure. Transmission electron microscopy of multiblocks shows phase separation with PIB (95–70 mol%) the continuous phase (Tg = −73°C) and cy-PIP blocks (5–30 mol %) the discrete phase. The Tg of the cy-PIP domain is in the range 95–190°C and it is affected by the extent of cyclization and/or the length of the cy-PIP sequence. The new multiblock TPEs are soluble in organic solvents and can be melt-processed above ∼ 140°C. A multiblock TPE film containing 15 mol % glassy cy-PIP block and 85 mol % rubbery PIB block of M̄n = 55,500 cast from CCl4 exhibited to MPa tensile strength [120 MPa engineering strength (sigma true)] and 1200% elongation. The completely cyclized linear triblock shows higher Tg (≡ 180°C) but, due to its low cy-PIP content, exhibits unsatisfactory tensile properties