Basement-cover relations and internal structure of the Cape Smith klippe: A 1.9 Ga greenstone belt in northern Quebec, Canada

The Cape Smith Belt is a 380x60 km tectonic klippe composed of greenschistto amphibolite-grade mafic and komatiitic lava flows and fine-grained quartzose sediment, intruded by minor syn- to post-tectonic granitoids. Previously studied transects in areas of relatively high structural level show that the belt is constructed of seven or more north-dipping thrust sheets which verge toward the Superior Province (Archean) foreland in the south and away from an Archean basement massif (Kovik Antiform) external to the Trans-Hudson Orogen (Early Proterozoic) in the north. A field project (mapping and structural-stratigraphic-metamorphic studies) directed by MRS was begun in 1985 aimed at the structurally deeper levels of the belt and underlying basement, which are superby exposed in oblique cross-section (12 km minimum structural relief) at the west-plunging eastern end of the belt. Mapping now complete of the eastern end of the belt confirms that all of the metavolcanic and most of the metasedimentary rocks are allochthonous with respect to the Archean basement, and that the thrusts must have been rooted north of Kovik Antiform. The main findings follow

A 3D insight on the catalytic nanostructuration of few-layer graphene

The catalytic cutting of few-layer graphene is nowadays a hot topic in materials research due to its potential applications in the catalysis field and the graphene nanoribbons fabrication. We show here a 3D analysis of the nanostructuration of few-layer graphene by iron-based nanoparticles under hydrogen flow. The nanoparticles located at the edges or attached to the steps on the FLG sheets create trenches and tunnels with orientations, lengths and morphologies defined by the crystallography and the topography of the carbon substrate. The cross-sectional analysis of the 3D volumes highlights the role of the active nanoparticle identity on the trench size and shape, with emphasis on the topographical stability of the basal planes within the resulting trenches and channels, no matter the obstacle encountered. The actual study gives a deep insight on the impact of nanoparticles morphology and support topography on the 3D character of nanostructures built up by catalytic cutting

Polyol synthesis, functionalisation, and biocompatibility studies of superparamagnetic iron oxide nanoparticles as potential MRI contrast agents

Iron oxide nanoparticles (IONPs) of low polydispersity were obtained through a simple polyol synthesis in high pressure and high temperature conditions. The control of the size and morphology of the nanoparticles was studied by varying the solvent used, the amount of iron precursor and the reaction time. Compared with conventional synthesis methods such as thermal decomposition or co-precipitation, this process yields nanoparticles with a narrow particle size distribution in a simple, reproducible and cost effective manner without the need for an inert atmosphere. For example, IONPs with a diameter of ca. 8 nm could be made in a reproducible manner and with good crystallinity as evidenced by X-ray diffraction analysis and high saturation magnetization value (84.5 emu g(-1)). The surface of the IONPs could be tailored post synthesis with two different ligands which provided functionality and stability in water and phosphate buffer saline (PBS). Their potential as a magnetic resonance imaging (MRI) contrast agent was confirmed as they exhibited high r1 and r2 relaxivities of 7.95 mM(-1) s(-1) and 185.58 mM(-1) s(-1) respectively at 1.4 T. Biocompatibility and viability of IONPs in primary human mesenchymal stem cells (hMSCs) was studied and confirmed

Observations on Fisheries Activities at Navassa Island

Unmanaged and unquantified artisanal fishing is ongoing at Navassa Island, a small oceanic island about 70 km west of Haiti that is part of the U.S. Caribbean Islands National Wildlife Refuge. Concern has been expressed regarding the possible impact of these fishing activities on reef resources, and no quantitative catch or effort data are available. However, informal qualitative observations made during a cruise in November 2002 suggest that escalation in fishing activity (and impact) has occurred since previous observations made in April 2000. Namely, size structure of fish was markedly reduced and the adoption of net fishing has allowed the exploitation of queen conch, Strombas gigas, and hawksbill turtles, Eretmochelys imbricata

Berenstein-Zelevinsky triangles, elementary couplings and fusion rules

We present a general scheme for describing su(N)_k fusion rules in terms of elementary couplings, using Berenstein-Zelevinsky triangles. A fusion coupling is characterized by its corresponding tensor product coupling (i.e. its Berenstein-Zelevinsky triangle) and the threshold level at which it first appears. We show that a closed expression for this threshold level is encoded in the Berenstein-Zelevinsky triangle and an explicit method to calculate it is presented. In this way a complete solution of su(4)_k fusion rules is obtained.Comment: 14 page

Small iron oxide nanoparticles as MRI T1 contrast agent: scalable inexpensive water-based synthesis using a flow reactor

Small iron oxide nanoparticles (IONPs) were synthesised in water via co-precipitation by quenching particle growth after the desired magnetic iron oxide phase formed. This was achieved in a millifluidic multistage flow reactor by precisely timed addition of an acidic solution. IONPs (≤5 nm), a suitable size for positive T1 magnetic resonance imaging (MRI) contrast agents, were obtained and stabilised continuously. This novel flow chemistry approach facilitates a reproducible and scalable production, which is a crucial paradigm shift to utilise IONPs as contrast agents and replace currently used Gd complexes. Acid addition had to be timed carefully, as the inverse spinel structure formed within seconds after initiating the co-precipitation. Late quenching allowed IONPs to grow larger than 5 nm, whereas premature acid addition yielded undesired oxide phases. Use of a flow reactor was not only essential for scalability, but also to synthesise monodisperse and non-agglomerated small IONPs as (i) co-precipitation and acid addition occurred at homogenous environment due to accurate temperature control and rapid mixing and (ii) quenching of particle growth was possible at the optimum time, i.e., a few seconds after initiating co-precipitation. In addition to the timing of growth quenching, the effect of temperature and dextran present during co-precipitation on the final particle size was investigated. This approach differs from small IONP syntheses in batch utilising either growth inhibitors (which likely leads to impurities) or high temperature methods in organic solvents. Furthermore, this continuous synthesis enables the low-cost (<£10 per g) and large-scale production of highly stable small IONPs without the use of toxic reagents. The flow-synthesised small IONPs showed high T1 contrast enhancement, with transversal relaxivity (r2) reduced to 20.5 mM−1 s−1 and longitudinal relaxivity (r1) higher than 10 mM−1 s−1, which is among the highest values reported for water-based IONP synthesis

Aircraft Emissions: Current Inventories and Future Scenarios

Three-dimensional (latitude, longitude, altitude) global inventories of civil and military aircraft fuel burned and emissions have been developed for the United States National Aeronautics and Space Administration (NASA) for the years 1976, 1984, and 1992, and by the European Abatement of Nuisances Caused by Air Transport (ANCAT)/European Commission (EC) Working Group and the Deutsches Zentrum für Luft- und Raumfahrt (DLR) for 1991/92. For 1992, the results of the inventory calculations are in good agreement, with total fuel used by aviation calculated to be 129.3 Tg (DLR), 131.2 Tg (ANCAT), and 139.4 Tg (NASA). Total emissions of NOx (as N02) in 1992 were calculated to range from 1.7 Tg (NASA) to 1.8 Tg (ANCAT and DLR). Forecasts of air travel demand and technology developed by NASA and ANCAT for 2015 have been used to create three-dimensional (3-D) data sets of fuel burn and NOx emissions for purposes of modeling the near-term effects of aircraft. The NASA 2015 forecast results in a global fuel burn of 309 Tg, with a NOx emission of 4.1 Tg (as N02); the global emission index, EI(NOx) (g NOx/kg fuel), is 13.4. In contrast, the ANCAT 2015 forecast results in lower values-a global fuel burn of 287 Tg, an emission of 3.5 Tg of NOx and a global emission index of 12.3. The differences arise from the distribution of air travel demand and technology assumptions

Pathological Narcissism in Adolescents: Relationships with Childhood Maltreatment and Internalizing and Externalizing Difficulties

Background: There are significant gaps in our understanding of vulnerable and grandiose narcissism in adolescents and whether it is associated with psychosocial difficulties as well as risk factors such as child maltreatment. Objective: The aim of this study was to examine vulnerable and grandiose narcissism in adolescents and young adults. Method: 570 participants (ages 14-21) from the community completed an online survey. Vulnerable and grandiose narcissism were assessed with the Pathological Narcissism Inventory, while psycho-social difficulties were assessed with the Child Behaviour Checklist and maltreatment with the Childhood Experiences of Care and Abuse Questionnaire. Results: Gender-specific age trends were identified, with narcissism appearing to decrease with age for females, while increasing for males into early adulthood. For females, vulnerable and grandiose narcissism was associated with maltreatment and partially mediated the relationship between abuse and neglect and internalizing and externalizing difficulties. Conclusion: These findings underscore the importance of considering the relationship between childhood maltreatment experiences and suggest that the relationship between such experiences and adolescent psychosocial difficulties may be partially accounted for by the negative impact that maltreatment has on narcissism