Pressure-Temperature Conditions of Granulite Formation in Rogaland, SW Norway

The geology of SW Norway is dominated by high-grade amphibolite to granulite facies gneisses with associated migmatites and anorthosite-magerite complexes. Previous work suggests that metamorphism consisted of two high temperature events at 1.45 Ga (MI) and 1.0 Ga (M2), followed by regional cooling and formation of retrograde assemblages (M3). Partial reequilibration of certain mineral phases has led to some uncertainty about the pressures of metamorphism and whether the retrograde assemblages represent a discrete metamorphic event. Pressure and temperature conditions of the M2 metamorphism of gneisses located near the osumilite-in isograd were constrained using gt-opx, opx-bt, cord-btgt, and gt-sill-qt-plag equilibria. Core compositions were used for all ferromagnesium phases to avoid the effects of Fe-Mg exchange during cooling. Results suggest that peak metamorphism occurred at pressures of 5-6 kb and temperatures of 71O-800°C. Rim temperatures and pressures were estimated at 490-550°C and 4-5 kb, suggesting retrograde metamorphism, and possibly implying isobaric cooling.No embarg

Similar Microbial Communities Found on Two Distant Seafloor Basalts.

The oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lō'ihi Seamount, Hawai'i, and the East Pacific Rise (EPR; 9°N). Phylogenetic analysis indicates the presence of a total of 43 bacterial and archaeal mono-phyletic groups, dominated by Alpha- and Gammaproteobacteria, as well as Thaumarchaeota. Functional gene analysis suggests that these Thaumarchaeota play an important role in ammonium oxidation on seafloor basalts. In addition to ammonium oxidation, the seafloor basalt habitat reveals a wide spectrum of other metabolic potentials, including CO2 fixation, denitrification, dissimilatory sulfate reduction, and sulfur oxidation. Basalt communities from Lō'ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy

Evidence-Based and Community Engaged Pandemic Responses for Calgary

Pandemics unduly burden those who are already economically and socially disadvantaged by poverty, disability, marginalization, and other vulnerabilities. Global pandemics increase disparities experienced by society’s most vulnerable, as inadequacies in systems-level protections make services challenging to access during emergencies. Families are specifically at risk, especially if they experience economic and social disparity concurrently with the pandemic. This study focuses on examining the way COVID-19 has exacerbated challenges to evidence based practice (EBP) implementation for community organizations in Calgary. Here we describe circumstances that make families vulnerable, the community organizations that support these families during the pandemic, and challenges with implementing EBP. To better understand policy barriers and facilitators as they relate to EBP access throughout the pandemic in Calgary, we conducted focus groups using the Nominal Group Technique (NGT) with diverse individuals representing local community organizations. Participants articulated the structural disparities that impede access to community-based EBP during the pandemic, and recognized potential solutions. The major themes uncovered in the research, as they apply to barriers to evidence-based service provision, included reduced revenue streams, access to technology, and lack of collaborative communication within and between ministries, as well as sectors. Proposed solutions to these barriers included person-centred policy and program approaches and reciprocal partnerships

Scientific Gerrymandering & Bifurcation

Environmental litigation must often examine the propriety of corporate conduct in areas of scientific complexity. In the second generation of climate nuisance suits, for example, allegations of corporate participation in the climate disinformation campaign are woven into plaintiffs’ claims. Toxic tort suits, currently and most notably in the Roundup and PFAS litigation, present another area of environmental litigation grappling with the legal ramifications of alleged corporate deception about scientific information. Toxic tort suits often surface allegations, and in many cases disturbing evidence, of what we term corporate “scientific gerrymandering”— corporate efforts to finesse, slow, or even mislead scientific understanding of the toxicity of chemicals and other products. The manner and extent to which scientific gerrymandering is explored and litigated within those suits is often driven by another typical feature of toxic tort litigation—the procedural device of bifurcation. Judges frequently bifurcate toxic tort suits into causation and negligence phases, with the causation phase heard first. Bifurcation in toxic tort suits involving issues of scientific gerrymandering requires judges to decide whether evidence of scientific gerrymandering is relevant to and may be presented during the causation phase of a toxic tort trial. And, typically, as Judge Vince Chhabria recently ruled in In re Roundup Products Liability Litigation (MDL No. 2741), judges hold that evidence of scientific gerrymandering cannot be presented or must be evidence of scientific gerrymandering cannot be presented or must be significantly limited during the causation phase because scientific gerrymandering is not relevant to causation. Rulings that prevent admitting evidence of scientific gerrymandering during the causation phase of bifurcated trials can, however, be critiqued on both doctrinal and normative grounds. First, from a doctrinal perspective, scientific gerrymandering—how a corporate defendant shaped scientific knowledge about a product’s risk—is often directly relevant to causation— whether the product causes the relevant harm. This is so because effective corporate scientific gerrymandering can define the current state of science about product risk, particularly when questions about the extent of risk caused by a product lie at the frontiers of scientific knowledge. Additionally, numerous tort doctrines support shifting or reducing causal burdens in the face of defendant misconduct, like scientific gerrymandering—which might be likened to obscuring evidence. Second, from a normative perspective, permitting consideration of scientific gerrymandering during causation can be justified even where the introduction of such evidence creates the risk that juries will erroneously find that a product causes harm. Condemnation of scientific gerrymandering is consistent with corrective justice because corporate scientific gerrymandering can occasion distinct and independent harm by creating a large group of exposed individuals who endure an extended period of fearful uncertainty until such time as the nature of that risk can be objectively resolved, even if that product is ultimately shown not to cause the suspected harm. Finally, from a policy perspective, allowing the introduction of evidence of corporate scientific gerrymandering during the causation phase of bifurcated toxic tort trials should discourage corporate actors from engaging in scientific gerrymandering, thereby improving the efficacy of regulation and bolstering public confidence

Quantifying microbial utilization of petroleum hydrocarbons in salt-marsh sediments using the ^(13)C content of bacterial rRNA

Natural remediation of oil spills is catalyzed by complex microbial consortia. Here we take a whole-community approach to investigate bacterial incorporation of petroleum hydrocarbons from a simulated oil spill. We utilized the natural difference in carbon-isotopic abundance between a salt marsh ecosystem supported by the ^(13)C-enriched C4 grass, Spartina alterniflora, and the ^(13)C-depleted composition of petroleum to monitor changes in the ^(13)C content of biomass. Magnetic-bead capture methods for the selective recovery of bacterial RNA were used to monitor the ^(13)C content of bacterial biomass during a two-week experiment. The data show that by the end of the experiment, up to 26% of bacterial biomass derived from consumption of the freshly-spilled oil. The results contrast with the inertness of a nearby relict spill, which occurred in 1969 in West Falmouth, MA. Sequences of 16S rRNA genes from our experimental samples also were consistent with previous reports suggesting the importance of {gamma}- and {delta}-Proteobacteria and Firmicutes in the remineralization of hydrocarbons. The magnetic-bead capture approach makes it possible to quantify uptake of petroleum hydrocarbons by microbes in-situ. Although employed here at the Domain level, RNA-capture procedures can be highly specific. The same strategy could be used with genus-level specificity, something which is not currently possible using the ^(13)C content of biomarker lipids

The Deep Subsurface Biosphere in Igneous Ocean Crust: Frontier Habitats for Microbiological Exploration

We discuss ridge flank environments in the ocean crust as habitats for subseafloor microbial life. Oceanic ridge flanks, areas far from the magmatic and tectonic influence of seafloor spreading, comprise one of the largest and least explored microbial habitats on the planet. We describe the nature of selected ridge flank crustal environments, and present a framework for delineating a continuum of conditions and processes that are likely to be important for defining subseafloor microbial "provinces." The basis for this framework is three governing conditions that help to determine the nature of subseafloor biomes: crustal age, extent of fluid flow, and thermal state. We present a brief overview of subseafloor conditions, within the context of these three characteristics, for five field sites where microbial studies have been done, are underway, or have been proposed. Technical challenges remain and likely will limit progress in studies of microbial ridge flank ecosystems, which is why it is vital to select and design future studies so as to leverage as much general understanding as possible from work focused at a small number of sites. A characterization framework such that as presented in this paper, perhaps including alternative or additional physical or chemical characteristics, is essential for achieving the greatest benefit from multidisciplinary microbial investigations of oceanic ridge flanks

Left ventricular mechanical, cardiac autonomic and metabolic responses to a single session of high intensity interval training.

High-intensity interval training (HIIT) produces significant health benefits. However, the acute physiological responses to HIIT are poorly understood. Therefore, we aimed to measure the acute cardiac autonomic, haemodynamic, metabolic and left ventricular mechanical responses to a single HIIT session. Fifty young, healthy participants completed a single HIIT session, comprising of three 30-s maximal exercise intervals on a cycle ergometer, interspersed with 2-min active recovery. Cardiac autonomics, haemodynamics and metabolic variables were measured pre-, during and post-HIIT. Conventional and speckle tracking echocardiography was used to record standard and tissue Doppler measures of left ventricular (LV) structure, function and mechanics pre- and post-HIIT. Following a single HIIT session, there was significant post-exercise systolic hypotension (126 ± 13 to 111 ± 10 mmHg, p < 0.05), parallel to a significant reduction in total peripheral resistance (1640 ± 365 to 639 ± 177 dyne⋅s⋅cm , p < 0.001) and significant increases in baroreceptor reflex sensitivity and baroreceptor effectiveness index (9.2 ± 11 to 24.8 ± 16.7 ms⋅mmHg and 41.8 ± 28 to 68.8 ± 16.2, respectively) during recovery compared to baseline. There was also a significant increase in the low- to high-frequency heart rate variability ratio in recovery (0.7 ± 0.48 to 1.7 ± 1, p < 0.001) and significant improvements in left ventricular global longitudinal strain (- 18.3 ± 1.2% to - 29.2 ± 2.3%, p < 0.001), and myocardial twist mechanics (1.27 ± 0.72 to 1.98 ± 0.72°·cm , p = 0.028) post-HIIT compared to baseline. A single HIIT session is associated with acute improvements in autonomic modulation, haemodynamic cardiovascular control and left ventricular function, structure and mechanics. The acute responses to HIIT provide crucial mechanistic information, which may have significant acute and chronic clinical implications. [Abstract copyright: © 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Integrated Fe- and S-isotope study of seafloor hydrothermal vents at East Pacific Rise 9–10°N

Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Chemical Geology 252 (2008): 214-227, doi:10.1016/j.chemgeo.2008.03.009.In this study, we report on coupled Fe- and S-isotope systematics of hydrothermal fluids and sulfide deposits from the East Pacific Rise at 9-10°N to better constrain processes affecting Fe- isotope fractionation in hydrothermal environments. We aim to address three fundamental questions: (1) is there significant Fe isotope fractionation during sulfide precipitation? (2) Is there significant variability of Fe-isotope composition of the hydrothermal fluids reflecting sulfide precipitation in subsurface environments? (3) Are there any systematics between Fe- and S- isotopes in sulfide minerals? The results show that chalcopyrite, precipitating in the interior wall of a hydrothermal chimney displays a limited range of δ56Fe values and δ34S values, between –0.11 to –0.33‰ and 2.2 to 2.6‰ respectively. The δ56Fe values are, on average, slightly higher by 0.14‰ relative to coeval vent fluid composition while δ34S values suggest significant S-isotope fractionation (-0.6±0.2‰) during chalcopyrite precipitation. In contrast, systematically lower δ56Fe and δ34S values relative to hydrothermal fluids, by up to 0.91‰ and 2.0‰ respectively, are observed in pyrite and marcasite precipitating in the interior of active chimneys. These results suggest isotope disequilibrium in both Fe- and S-isotopes due to S-isotopic exchange between hydrothermal H2S and seawater SO42- followed by rapid formation of pyrite from FeS precursors, thus preserving the effects of a strong kinetic Fe-isotope fractionation during FeS precipitation. In contrast, δ56Fe and δ34S values of pyrite from inactive massive sulfides, which show evidence of extensive late-stage reworking, are essentially similar to the hydrothermal fluids. Multiple stages of remineralization of ancient chimney deposits at the seafloor appear to produce minimal Fe-isotope fractionation. Similar affects are indicated during subsurface sulfide precipitation as demonstrated by the lack of systematic differences between δ56Fe values in both high-temperature, Fe-rich black smokers and lower temperature, Fe-depleted vents.Support for W. Bach and K. Edwards was provided by NSF grant OCE-0241791 and support for O. Rouxel was provided by funding from the WHOI Deep Ocean Exploration Institute and NSF grant OCE-0622982 and OCE-0647948

“We wanted to see if you were the real deal”: Teaching as a cultural practice in a challenging environment

Teaching can be viewed as a cultural practice in which teaching is embedded in the culture of the teacher and informed by the culture of the students (Bell, 2011). In this paper, a narrative is presented detailing an authentic example of teaching in New Zealand in which culture is prioritised. It describes the challenges faced by a young female teacher as she worked in a low decile secondary school with male students, the majority of whom were involved in the Mongrel Mob[1] gang. Her approach and responses were centred in her belief in culturally responsive teaching. The deliberate actions of the teacher led to a turning point for the students, allowing their mana to remain intact as she acknowledged their identity, language and culture. This teacher’s experience provides an example of how a teacher can enable learners in diverse classrooms to succeed in their learning

Characterization of Attachment and Growth of Thiobacillus denitrificans on Pyrite Surfaces

Anaerobic growth and attachment of the autotrophic denitrifying bacterium Thiobacillus denitrificans on pyrite surfaces were studied. Polished pyrite slabs were exposed to T. denitrificans for 1 to 9 weeks. The reacted pyrite surfaces were imaged with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Cells were observed as isolated attached cells, cells in division and cells forming microcolonies embedded in organic films. Bacteria began to colonize pyrite surfaces after 1 week, forming microcolonies after 3 weeks. The rate of colonization of the pyrite surface was around 35 cells mm−2 h−1 for the 3-week period. After 9 weeks, larger areas of the pyrite surface were covered by organic films. Bacterial enumeration on the pyrite surface and in solution showed that most of the cells were not attached to the mineral surface. Nevertheless, both attached and free-living bacteria probably contributed to pyrite-driven denitrification. The results may be applied to the natural environment to better understand pyrite-driven denitrification in aquifers and to improve the long-term performance of bioremediation processes using pyrite