76 research outputs found
The Architecture of a Root Zone of a Large Magmatic Conduit System From High Resolution Magnetic, Gravity and Petrophysical Data: The Reinfjord Ultramafic Complex
The Seiland Igneous Province (SIP) is a large province of mafic and ultramafic (UM) complexes interpreted to be relics of a giant plumbing system feeding the Ediacaran Central Iapetus Magmatic Province. The Reinfjord Ultramafic Complex (RUC) is one of the four major ultramafic complexes of the SIP. The RUC has a younger dunite core surrounded by wehrlite and lherzolite embedded in country rocks consisting of layered gabbros with sub-horizontal layering and metamorphosed sedimentary rocks. Here, we develop a 3D subsurface model for the RUC using high-resolution magnetic and gravity data and extensive petrophysical measurements from oriented surface samples and drill core samples. Our model indicates that the RUC narrows in depth, extending a minimum of 1.4Â km below sea level, and plunges eastwards below the country rock. This model allows us to decipher the lithologic heterogeneities, and the depth and lateral extent of ultramafic rocks, which we interpret in the context of the geologic history of the area. The RUC is spatially separated from other UM complexes of the SIP and the result of this study indicates a smaller depth extent. Combining these findings with the previously reported distribution of the SIP rocks based on the regional gravity data, we propose that the uplift of the crustal block hosting the RUC is larger than for ultramafic complexes in the northwestern part of the SIP
Student loneliness through the pandemic : how, why and where?
Loneliness has emerged as a problem for individuals and society. A group whose loneliness has recently grown in severity and visibility is students in higher education. Complementing media reports and surveys of studentsâ lockdown loneliness, this paper presents qualitative research findings on students loneliness during the COVID-19 pandemic. It explores the how, why and where of student loneliness through research co-produced with undergraduate and postgraduate students. Student-researchers investigated loneliness as a function of relationships and interactions through self-interviews and peer interviews (n = 46) and through objects, chosen by participants to represent their experiences of lockdown. This research led to three conclusions, each with a geographical focus. First, as the spaces in which students live and study were fragmented, interactions and relationships were disrupted. Second, students struggled to put down roots in their places of study. Without a sense of belongingâto the city and institution where they studied, and the neighbourhood and accommodation where they livedâthey were more likely to experience loneliness. Third, many students were unable to progress through life transitions associated with late adolescence including leaving home, learning social skills, forming sexual relationships and emerging into adulthood. Those facing bigger changes such as bereavement struggled to process these events and spoke of feeling âneither here nor thereââin limbo. But students displayed resilience, finding ways to cope with and mitigate their loneliness. Their coping strategies speak to the efforts of policymakers and practitionersâincluding those in universities, government, health and wellbeing services, and accommodation servicesâwho are seeking ways to tackle students' (and other peoples') loneliness
An international reproducibility study validating quantitative determination of ERBB2, ESR1, PGR, and MKI67 mRNA in breast cancer using MammaTyper (R)
Background: Accurate determination of the predictive markers human epidermal growth factor receptor 2 (HER2/ERBB2), estrogen receptor (ER/ESR1), progesterone receptor (PgR/PGR), and marker of proliferation Ki67 (MKI67) is indispensable for therapeutic decision making in early breast cancer. In this multicenter prospective study, we addressed the issue of inter- and intrasite reproducibility using the recently developed reverse transcription-quantitative real-time polymerase chain reaction-based MammaTyper (R) test. Methods: Ten international pathology institutions participated in this study and determined messenger RNA expression levels of ERBB2, ESR1, PGR, and MKI67 in both centrally and locally extracted RNA from formalin-fixed, paraffin-embedded breast cancer specimens with the MammaTyper (R) test. Samples were measured repeatedly on different days within the local laboratories, and reproducibility was assessed by means of variance component analysis, Fleiss' kappa statistics, and interclass correlation coefficients (ICCs). Results: Total variations in measurements of centrally and locally prepared RNA extracts were comparable; therefore, statistical analyses were performed on the complete dataset. Intersite reproducibility showed total SDs between 0.21 and 0.44 for the quantitative single-marker assessments, resulting in ICC values of 0.980-0.998, demonstrating excellent agreement of quantitative measurements. Also, the reproducibility of binary single-marker results (positive/negative), as well as the molecular subtype agreement, was almost perfect with kappa values ranging from 0.90 to 1.00. Conclusions: On the basis of these data, the MammaTyper (R) has the potential to substantially improve the current standards of breast cancer diagnostics by providing a highly precise and reproducible quantitative assessment of the established breast cancer biomarkers and molecular subtypes in a decentralized workup.Peer reviewe
Mapping and Modeling Sources of Natural Remanent Magnetization in the MicroclineâSillimanite Gneiss, Northwest Adirondack Mountains: Implications for Crustal Magnetism
Abstract Distinct crustal remanent magnetic anomalies are a strong indicator of rocks with stable natural remanent magnetization (NRM) carriers. The latter are able to store information on the history of a rock over long geological periods, and can therefore be used for a variety of applications in the field of paleomagnetism and rock magnetism. Typically, paleomagnetic and rockâmagnetic studies rely on rocks bulk magnetic properties. With the advent of highâresolution magnetometric scanning techniques, it is now possible to map magnetic sources at the mineral scale, identify the different magnetic carriers, and analyze the effect of geometry, microstructures, and composition on their magnetic response. We investigate the stability of discrete remanent magnetization sources of a microclineâsillimanite gneiss sample from Russell Belt with a strong NRM, by scanning the sample before, and after alternating field demagnetization to 100Â mT. We quantified changes in the magnetization intensity and direction by inverting the magnetic scan data. Here, we confirm that the exsolved titanohematite with ilmenite lamellae is the major source of magnetization, and the coexisting multidomain hematite grains contribute little to the NRM, or the magnetic anomalies. The microstructures in the titanohematite control local magnetic properties at the mineral scale. Magnetic modeling results suggest a consistent average magnetization direction before and after demagnetization at both the grain and thin section scale, with a decrease in the magnetization intensity of â30%. Results are consistent with previous bulk magnetic measurements and the likelihood to use highâresolution magnetometric techniques in future magnetic studies is high
Do pool surface area and depth control CO2 and CH4 fluxes from an ombrotrophic raised bog, James Bay, Canada?
The relationship between the exchange of COâ and CHâ and the surface area and depth of 16 pools on a northern peatland was investigated over 2 years. Differences in carbon gas emissions were found, with small, shallow pools (<1000 mÂČ, <0.45 m) having consistently larger COâ and CHâ fluxes. Average CHâ fluxes decreased with increasing pool depth and were between 1 and 5 times larger from shallow pools (0.3 m, p < 0.001) than from deeper pools (0.7 m). Average COâ fluxes also generally decreased with increasing pool depth and were between 1 and 4 times larger from shallower pools (0.3 m, 0.45 m, p < 0.004) than from deeper pools (0.75 m). Average pool C-COâ losses in 2005 were approximately 3 to 30 times lower (0.11 g C mâ»ÂČ) than dark respiration COâ losses from the adjacent vegetated section of the peatland. All pools, regardless of size, were atmospheric sources of COâ and CHâ over the sampling period at an average emission ratio of 1C-COâ:1.5C-CHâ, with total carbon losses of 20.1 g C mâ»ÂČ and 29.6 g C mâ»ÂČ over 2004 and 2005. Consistently larger fluxes to atmosphere of both COâ and CHâ from shallow pools (<0.45 m) suggest that enhanced decomposition could be occurring, accounting for the differences in carbon gas exchange
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