In Conversation with Mubin Shaikh: From Salafi Jihadist to Undercover Agent inside the "Toronto 18" Terrorist Group

This interview with former undercover agent Mubin Shaikh can help academics and security practitioners understand the key role played and the challenges faced by covert human intelligence sources within domestic terrorist groups. The interview highlights the identity crisis, the personal factors, and the allure of jihadi militancy that initially drove Shaikh to join a Salafi jihadist group. It investigates Shaikh’s process of disengagement from the Salafi jihadist belief system and his rediscovery of a moderate, inclusive, and benevolent form of Islam. It explores his work as an undercover agent for the Canadian Security Intelligence Service, the Royal Canadian Mounted Police, and the Integrated National Security Enforcement Team responsible for disrupting domestic terrorist groups. The “Toronto 18” terrorist cell, the key role played by undercover agents in preventing terrorist action, and the challenges posed by entrapment are also discussed

Numerical model validation for mooring systems: Method and application for wave energy converters

PublishedArticleMooring systems are key sub-systems of wave energy devices. The design of mooring systems is challenging because overdesign of the mooring system incurs a significant cost penalty, while underdesign may lead to a premature failure. Incorrect design could also reduce the power production. It is therefore important to develop mooring systems which are specific for wave energy applications. In particular, very compliant mooring systems which allow the system to be highly dynamic are being developed. The validation of numerical models with data from physical experiments would facilitate the development of appropriate mooring solutions. This paper presents tank test results for a scale model of the buoy and mooring used at the South West Mooring Test Facility (SWMTF), an offshore facility developed to conduct long-term sea trials for wave energy device moorings. The mooring system investigated is a compliant 3 leg catenary mooring system using Nylon ropes in the water column. Preliminary static, quasi-static, decay, regular and irregular wave tests were conducted on the 1:5 scale model, using the Ifremer basin in Brest. A corresponding numerical model was developed with a time-domain mooring modelling tool, inputting hydrodynamic data from a radiation/diffraction potential modelling program. After the calibration of several hydrodynamic parameters (added mass, damping and mean drift), the numerical model demonstrated good agreement with the experiment, providing an accurate prediction of the maximum mooring loads in irregular waves. However, results show large differences with the field test results, mainly because of the anchor position. The methods and procedures presented will allow the effective validation of numerical models to enable the development of appropriate mooring systems in wave energy applications.The authors acknowledge the support of the MERiFIC (4122) project partners (Marine Energy in Far Peripheral and Island Communities, http://www.merific.eu) and of MARINET, a European Community Research Infrastructure Action under the FP7 Capacities Specific Programme (262552) (www.fp7-marinet.eu). The authors would like to acknowledge the support of the South West Regional Development Agency for its support through the PRIMaRE institution and the support towards the FabTest through the Regional Growth Fund. The authors are grateful for the valuable support of the Ifremer team: Emmanuel Mansuy, Aurélien Tancray, Christophe Maisondieu and Peter Davies. The authors also want to thank Orcina for their technical support

Lewis X antigen mediates adhesion of human breast carcinoma cells to activated endothelium. Possible involvement of the endothelial scavenger receptor C-Type lectin

Lewis x (Lex, CD15), also known as SSEA-1 (stage specific embryonic antigen-1), is a trisaccharide with the structure Galβ(1–4)Fucα(1–3)GlcNAc, which is expressed on glycoconjugates in human polymorphonuclear granulocytes and various tumors such as colon and breast carcinoma. We have investigated the role of Lex in the adhesion of MCF-7 human breast cancer cells and PMN to human umbilical endothelial cells (HUVEC) and the effects of two different anti-Lex mAbs (FC-2.15 and MCS-1) on this adhesion. We also analyzed the cytolysis of Lex+-cells induced by anti-Lex mAbs and complement when cells were adhered to the endothelium, and the effect of these antibodies on HUVEC. The results indicate that MCF-7 cells can bind to HUVEC, and that MCS-1 but not FC-2.15 mAb inhibit this interaction. Both mAbs can efficiently lyse MCF-7 cells bound to HUVEC in the presence of complement without damaging endothelial cells. We also found a Lex-dependent PMN interaction with HUVEC. Although both anti-Lex mAbs lysed PMN in suspension and adhered to HUVEC, PMN aggregation was only induced by mAb FC-2.15. Blotting studies revealed that the endothelial scavenger receptor C-type lectin (SRCL), which binds Lex-trisaccharide, interacts with specific glycoproteins of Mr␣∼␣28 kD and 10 kD from MCF-7 cells. The interaction between Lex+-cancer cells and vascular endothelium is a potential target for cancer treatment.Fil: Elola, Maria Teresa. Fundación Instituto Leloir; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Capurro, Mariana Isabel. University of Toronto; CanadáFil: Barrio, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; ArgentinaFil: Coombs, Peter J.. Imperial College London; Reino UnidoFil: Taylor, Maureen E.. Imperial College London; Reino UnidoFil: Drickamer, Kurt. Imperial College London; Reino UnidoFil: Mordoh, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación, Docencia y Prevención del Cáncer; Argentin

Magnetic and Charge Correlations in La{2-x-y}Nd_ySr_xCuO_4: Raman Scattering Study

Two aspects in connection with the magnetic properties of La_{2-x-y}Nd_ySr_xCuO_4 single crystals are discussed. The first is related to long wavelength magnetic excitations in x = 0, 0.01, and 0.03 La_{2-x}Sr_xCuO_4 detwinned crystals as a function of doping, temperature and magnetic field. Two magnetic modes were observed within the AF region of the phase diagram. The one at lower energies was identified with the spin-wave gap induced by the antisymmetric DM interaction and its anisotropic properties in magnetic field could be well explained using a canonical form of the spin Hamiltonian. A new finding was a magnetic field induced mode whose dynamics allowed us to discover a spin ordered state outside the AF order which was shown to persist in a 9 T field as high as 100 K above the N\'eel temperature T_N for x = 0.01. For these single magnon excitations we map out the Raman selection rules in magnetic fields and demonstrate that their temperature dependent spectral weight is peaked at the N\'eel temperature. The second aspect is related to phononic and magnetic Raman scattering in La_{2-x-y}Nd_ySr_xCuO_4 with three doping concentrations: x = 1/8, y = 0; x = 1/8, y = 0.4; and x = 0.01, y = 0. We observed that around 1/8 Sr doping and independent of Nd concentration there exists substantial disorder in the tilt pattern of the CuO_6 octahedra in both the orthorhombic and tetragonal phases which persist down to 10 K and are coupled to bond disorder in the cation layers. The weak magnitude of existing charge/spin modulations in the Nd doped structure did not allow us to detect specific Raman signatures on lattice dynamics or two-magnon scattering around 2200 cm-1.Comment: 26 pages, 22 figure

Numerical Calculations of the B1g Raman Spectrum of the Two-Dimensional Heisenberg Model

The B1g Raman spectrum of the two-dimensional S=1/2 Heisenberg model is discussed within Loudon-Fleury theory at both zero and finite temperature. The exact T=0 spectrum for lattices with up to 6*6 sites is computed using Lanczos exact diagonalization. A quantum Monte Carlo (QMC) method is used to calculate the corresponding imaginary-time correlation function and its first two derivatives for lattices with up to 16*16 spins. The imaginary-time data is continued to real frequency using the maximum-entropy method, as well as a fit based on spinwave theory. The numerical results are compared with spinwave calculations for finite lattices. There is a surprisingly large change in the exact spectrum going from 4*4 to 6*6 sites. In the former case there is a single dominant two-magnon peak at frequency w/J appr. 3.0, whereas in the latter case there are two approximately equal-sized peaks at w/J appr. 2.7 and 3.9. This is in good qualitative agreement with the spinwave calculations including two-magnon processes on the same lattices. Both the Lanczos and the QMC results indicate that the actual infinite-size two-magnon profile is broader than the narrow peak obtained in spinwave theory, but the positions of the maxima agree to within a few percent. The higher-order contributions present in the numerical results are merged with the two-magnon profile and extend up to frequencies w/J appr. 7. The first three frequency cumulants of the spectrum are in excellent agreement with results previously obtained from a series expansion around the Ising limit. Typical experimental B1g$ spectra for La2CuO4 are only slightly broader than what we obtain here. The exchange constant extracted from the peak position is J appr. 1400K, in good agreement with values obtained from neutron scattering and NMR experiments.Comment: 15 pages, Revtex, 13 PostScript figure

The novel Fh8 and H fusion partners for soluble protein expression in Escherichia coli : a comparison with the traditional gene fusion technology

The Escherichia coli host system is an advantageous choice for simple and inexpensive recombinant protein production but it still presents bottlenecks at expressing soluble proteins from other organisms. Several efforts have been taken to overcome E. coli limitations, including the use of fusion partners that improve protein expression and solubility. New fusion technologies are emerging to complement the traditional solutions. This work evaluates two novel fusion partners, the Fh8 tag (8 kDa) and the H tag (1 kDa), as solubility enhancing tags in E. coli and their comparison to commonly used fusion partners. A broad range comparison was conducted in a small-scale screening and subsequently scaled-up. Six difficult-to-express target proteins (RVS167, SPO14, YPK1, YPK2, Frutalin and CP12) were fused to eight fusion tags (His, Trx, GST, MBP, NusA, SUMO, H and Fh8). The resulting protein expression and solubility levels were evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis before and after protein purification and after tag removal. The Fh8 partner improved protein expression and solubility as the well-known Trx, NusA or MBP fusion partners. The H partner did not function as a solubility tag. Cleaved proteins from Fh8 fusions were soluble and obtained in similar or higher amounts than proteins from the cleavage of other partners as Trx, NusA or MBP. The Fh8 fusion tag therefore acts as an effective solubility enhancer, and its low molecular weight potentially gives it an advantage over larger solubility tags by offering a more reliable assessment of the target protein solubility when expressed as a fusion protein.The financial support of the EMBL Heidelberg, Germany and Fundacao para a Ciencia e Tecnologia (FCT), Portugal, is acknowledged: the fellowship SFRH/BD/46482/2008 to Sofia J. Costa and the project PTDC/CVT/103081/2008. The authors wish to acknowledge Anne-Claude Gavin for providing four of the constructs for this study (RVS167, SPO14, YPK1, and YPK2) and Emmanuel Poilpre for the experimental help (both from the EMBL Heidelberg, Germany)

Therapeutic potential of oleic acid supplementation in myotonic dystrophy muscle cell models

Background: We recently reported that upregulation of Musashi 2 (MSI2) protein in the rare neuromuscular disease myotonic dystrophy type 1 contributes to the hyperactivation of the muscle catabolic processes autophagy and UPS through a reduction in miR-7 levels. Because oleic acid (OA) is a known allosteric regulator of MSI2 activity in the biogenesis of miR-7, here we sought to evaluate endogenous levels of this fatty acid and its therapeutic potential in rescuing cell differentiation phenotypes in vitro. In this work, four muscle cell lines derived from DM1 patients were treated with OA for 24 h, and autophagy and muscle differentiation parameters were analyzed. Results: We demonstrate a reduction of OA levels in different cell models of the disease. OA supplementation rescued disease-related phenotypes such as fusion index, myotube diameter, and repressed autophagy. This involved inhibiting MSI2 regulation of direct molecular target miR-7 since OA isoschizomer, elaidic acid (EA) could not cause the same rescues. Reduction of OA levels seems to stem from impaired biogenesis since levels of the enzyme stearoyl-CoA desaturase 1 (SCD1), responsible for converting stearic acid to oleic acid, are decreased in DM1 and correlate with OA amounts. Conclusions: For the first time in DM1, we describe a fatty acid metabolism impairment that originated, at least in part, from a decrease in SCD1. Because OA allosterically inhibits MSI2 binding to molecular targets, reduced OA levels synergize with the overexpression of MSI2 and contribute to the MSI2 > miR-7 > autophagy axis that we proposed to explain the muscle atrophy phenotype

Exploring an alternative for running experiments during social distancing: A pilot study of stimulus equivalence

Web-based platforms were useful tools for running psychology experiments remotely during the pandemic. They enabled the collection of behavioral data while keeping participants and researchers safe from infection threats imposed by the coronavirus crisis. This study focused on the generality of equivalence outcomes typically observed in basic research laboratories. Participants accessed the experimental task remotely and were trained in a matching-to-sample (MTS) task. The procedure was designed to establish conditional discriminations between (A) pictures of women expressing happiness and angriness (A1 and A2), and (B, C) several abstract shapes (B1, B2, C1, and C2). Upon completion of one-to-many training, participants were tested on MTS-probe trials designed to assess the non-trained equivalence relations BC (B1C1 and B2C2) and CB (C1B1 and C2B2). Finally, two semantic judgment blocks of trials assessed equivalence-priming effects for the B and C stimulus-stimulus relations and priming effects for semantically related words. Results showed the expected patterns based on equivalence class formation, that is, emergent BC and CB relations following training of AB and AC conditional discriminations, and semantic priming effects were observed in the semantic judgment trials. In general, these results suggest that studies on stimulus equivalence may be conducted by means of web-based platforms.publishedVersio