A steady state reaction of apparent equilibrium of K mica + Ca2+ ⇄ Ca vermiculite + K+ was indicated by prolonged dissolution extractions from Blount soil clay (from northern Indiana) abundant in dioctahedral mica and vermiculite, with log Keq = 2.92 for the reaction when extrapolated to infinite time. From this and published free energies of formation of mica and kaolinite, a mineral phase stability diagram depicting the phase joins of Ca vermiculite, muscovite, and kaolinite was constructed with the solute activity functions pH-pK+, 2pH-pCa2+, and pSi(OH)4. These solute functions for 14-day reactions of calcareous (and dolomitic), poorly drained Harps soil (from central Iowa) fell near the calcite-dolomite-CO2-H2O phase join, suggesting equilibrium. These functions for Harps soil and the control minerals muscovite, biotite, and (or) vermiculite plus calcite were plotted on the mica-vermiculite stability diagram for various CO2 partial pressures. The points fell on the vermiculite-stable side of the mica-vermiculite plane at CO2 partial pressures of 0.15 and 0.20 atm (similar to soil air that would exist under frozen soil during winter and early spring; 2pH-pCa2+ ≃ 10.3). They fell on the muscovite-stable side of the muscovite-vermiculite plane at CO2 partial pressures of 0.0001 and 0.001 atm (similar to soil air under natural summer conditions; 2pH-pCa2+, 13.6 and 12.6, respectively) and therefore K+ (and 137Cs+ in rainfall) would be expected to be fixed.

The 2pH-pMg2+ values determined for Harps soil at the various CO2 partial pressures plotted either in the Mg montmorillonite stability field or on the Mg-montmorillonite-kaolinite phase join, in concordance with the abundance of montmorillonite and some kaolinite in the medium and fine clay fractions. The solute values for the nearby Clarion soil (upland, noncalcareous) plotted on the montmorillonite-kaolinite join, or with higher CO2 partial pressure, in the kaolinite stability area. The Gibbs free energy of formation (△Gf0) for a dioctahedral Ca vermiculite of −1303.7 kcal per 010 was determined from the Keq. The solute functions for the Blount soil showed kaolinite to be the thermodynamically stable phase with respect to dioctahedral mica and (or) vermiculite. The 14-day solute values for the Harps and upland Clarion soils were also on the kaolinite stability side of the kaolinite-vermiculite join. The kinetics of kaolinite formation in the upper midwestern U.S.A. are apparently slow on a scale of ~ 104 years.

Three kinds of opal-cristobalite, differentiated by the sharpness of the 4·1 Å XRD peak, were isolated from the Helms (Texas) bentonite by selective chemical dissolution followed by specific gravity separation. The δ18O value (oxygen isotope abundance) for these cristobalite isolates ranged from approximately 26–30‰ (parts per thousand), increasing with increased breadth of the 4·1 Å XRD peak. Opal-cristobalite isolated from the Monterey diatomite had a δ18O value of 34‰. These δ18O values are in the range for Cretaceous cherts (approximately 32‰) and are unlike the values of 9–11‰ obtained for low-cristobalite (XRD peaks at 4·05, 3·13, 2·4, and 2·49) formed hydrothermally or isolated from the vesicles of obsidian. The morphology pseudomorphic after diatoms, observed with the scanning electron microscope, was more apparent in the opal-cristobalite from the Monterey diatomite of Miocene age (approximately 10 million yr old) than in the spongy textured opal-cristobalite from the Helms bentonite, reflecting the 40 million yr available for crystallization since Upper Eocene.

The oxygen isotope abundance of Helms montmorillonite (δ18O = 26‰) indicates that it was formed in sea water while the δ18O values of the associated opal-cristobalite indicate that this SiO2 polymorph probably formed at approximately 25°C in meteoric water. Although both cristobalite and mont-montmorillonite in the bentonite were authigenic, the crystallization of the SiO2 phase apparently required a considerably longer period and occurred mainly after tectonic uplift.

In contrast to the results for cristobalite, quartz from the Helms and Upton (Wyoming) bentonites had δ18O values of 15 and 21‰ respectively. Such intermediate values, similar to those of aerosolic dusts of the Northern Hemisphere, loess, and many fluvial sediments and shales of the North Central United States (U.S.A.), preclude either a completely authigenic or a completely igneous origin for the quartz. These values probably result from a mixing of quartz from high and low temperature sources, detritally added to the ash or bentonite bed.

From 2 to 28% opal-cristobalite was isolated from the 2–20 µm fraction of rhyolitic and andesitic tuffaceous pyroclastics from the Island of Honshu, Japan, where it had been formed in hydrothermal springs at temperatures of ∼25–170°C as calculated from the oxygen isotopic ratios (18O/16O). Three of the isolates gave X-ray powder diffractograms with strong peaks at 4.07 Å. Two of these also had very weak peaks at 4.32 Å indicative of the presence of traces of tridymite. The fourth isolate had a strong 4.11 Å cristobalite peak and a very weak 4.32 Å peak. The morphology, determined by the scanning electron microscope, varied with the formation temperature indicated by the oxygen isotopic ratio (δ18O), from spheroidal and spongy for the opal-cristobalite formed at ∼25°C (δ18O = 26.0‰) in contrast to angular irregular plates and prisms for that formed at ∼115°C (11.9‰), ∼135°C (7.9 ‰) and ∼170°C (6.8 ‰). The differences in δ18O values are attributed to variation in hydrothermal temperature, but some variability in oxygen isotopic composition of the water is possible. The field-measured temperatures related roughly with the calculated fractionation temperatures except in one site, while the contrast in cristobalite morphology related well to calculated low and high fractionation temperatures. Low-cristobalite of hydrothermal origin in New Zealand (δ18O = 9‰) had characteristic rounded grains with some evidence of platiness. Co-existing quartz grains (δ18O = 10‰) showed more subhedral and irregular prismatic morphology.

American Indians and Alaska Natives suffer from disproportionately high rates of chronic mental and physical health conditions. These health inequities are linked to colonization and its downstream consequences. Most of the American Indian and Alaska Native health inequities research uses a deficit framework, failing to acknowledge the resilience of American Indian and Alaska Native people despite challenging historical and current contexts. This scoping review is based on a conceptual model which acknowledges the context of colonization and its consequences (psychological and health risk factors). However, rather than focusing on health risk, we focus on protective factors across three identified domains (social, psychological, and cultural/spiritual), and summarize documented relationships between these resilience factors and health outcomes. Based on the scoping review of the literature, we note gaps in extant knowledge and recommend future directions. The findings summarized here can be used to inform and shape future interventions which aim to optimize health and well-being in American Indian and Alaska Native peoples.

We used a survey to characterize contemporary infection prevention and antibiotic stewardship program practices across 64 healthcare facilities, and we compared these findings to those of a similar 2013 survey. Notable findings include decreased frequency of active surveillance for methicillin-resistant Staphylococcus aureus, frequent active surveillance for carbapenem-resistant Enterobacteriaceae, and increased support for antibiotic stewardship programs.

Experiments in the system NaAlSiO4(Ne)−KAlSiO4(Ks)−SiO2(Qz)−H2O at 100 MPa show that the maximum content of NaAlSi2O6 in leucite is ∼4 wt.% and that analcime is close to the stoichiometric composition (NaAlSi2O6.H2O). Analcime forms metastably on quenching the higher-temperature experiments; it is secondary after leucite in experiments quenched from 780°C, while from 850°C it forms by alteration of leucite, and by devitrification of water-saturated glass. Both processes involve reaction with Na-rich aqueous fluids. Stable analcime forms at 500°C, well below the solidus, and cannot form as phenocrysts in shallow volcanic systems. New data for natural analcime macrocrysts in blairmorites are presented for the Crowsnest volcanics, Alberta, Canada. Other researchers have suggested that primary analcime occurs as yellow-brown, glassy, analcime phenocrysts. Our microprobe analyses show that such primary analcime is close to stoichiometric, with very low K2O (<0.1 wt.%), minor Fe2O3 (0.5−0.8 wt.%) and CaO (∼0.5 wt.%). An extrapolation of published experimental data for Ne−Ks−Qz at >500 MPa PH2O, where Anl + melt coexist, suggests that at >800 MPa two invariant points are present: (1) a reaction point involving Kf + Ab + Anl + melt + vapour; and (2) a eutectic with Kf + Anl + Ne + melt + vapour. We suggest that the nepheline-free equilibrium mineral assemblage for Crowsnest samples is controlled by reaction point (1). In contrast, blairmorites from Lupata Gorge, Mozambique, form at eutectic (2), consistent with the presence of nepheline phenocrysts. Our conclusions, based on high- vs. low-pressure experiments, confirm the suggestion made by other authors, that Crowsnest volcanic rocks must have been erupted explosively to preserve glassy analcime phenocrysts during very rapid, upward transport from deep in the crust (H2O pressures ≫500 MPa). Only rare examples survived the deuteric and hydrothermal alteration that occurred during and after eruption.

Background:ATP8A2 mutations have only recently been associated with human disease. We present the clinical features from the largest cohort of patients with this disorder reported to date. Methods: An observational study of 9 unreported and 2 previously reported patients with biallelic ATP8A2 mutations was carried out at multiple centres. Results: The mean age of the cohort was 9.4 years old (range: 2.5-28 yrs). All patients demonstrated developmental delay, severe hypotonia and movement disorders: chorea/choreoathetosis (100%), dystonia (27%) or facial dyskinesia (18%). Hypotonia was apparent at birth (70%) or before 6 months old (100%). Optic atrophy was observed in 75% of patients who had a funduscopic examination. MRI of the brain was normal for most patients with a small proportion showing mild cortical atrophy (30%), delayed myelination (20%) and/or hypoplastic optic nerves (20%). Epilepsy was seen in two older patients. Conclusions:ATP8A2 gene mutations have emerged as a cause of a novel phenotype characterized by developmental delay, severe hypotonia and hyperkinetic movement disorders. Optic atrophy is common and may only become apparent in the first few years of life, necessitating repeat ophthalmologic evaluation. Early recognition of the cardinal features of this condition will facilitate diagnosis of this disorder.

A new protocol for the quantitative determination of zeolite-group mineral compositions by electron probe microanalysis (wavelength-dispersive spectrometry) under ambient conditions, is presented. The method overcomes the most serious challenges for this mineral group, including new confidence in the fundamentally important Si-Al ratio. Development tests were undertaken on a set of natural zeolite candidate reference samples, representing the compositional extremes of Na, K, Cs, Mg, Ca, Sr and Ba zeolites, to demonstrate and assess the extent of beam interaction effects on each oxide component for each mineral. These tests highlight the variability and impact of component mobility due to beam interaction, and show that it can be minimized with recommended operating conditions of 15 kV, 2 nA, a defocused, 20 μm spot size, and element prioritizing with the spectrometer configuration. The protocol represents a pragmatic solution that works, but provides scope for additional optimization where required. Vital to the determination of high-quality results is the attention to careful preparations and the employment of strict criteria for data reduction and quality control, including the monitoring and removal of non-zeolitic contaminants from the data (mainly Fe and clay phases). Essential quality criteria include the zeolite-specific parameters of R value (Si/(Si + Al + Fe3+), the 'E%' charge-balance calculation, and the weight percent of non-hydrous total oxides. When these criteria are applied in conjunction with the recommended analytical operating conditions, excellent inter-batch reproducibility is demonstrated. Application of the method to zeolites with complex solid-solution compositions is effective, enabling more precise geochemical discrimination for occurrence-composition studies. Phase validation for the reference set was conducted satisfactorily with the use of X-ray diffraction and laser-ablation inductively-coupled plasma mass spectroscopy.

Patients with methicillin-resistant Staphylococcus aureus (MRSA) clones, which were traditionally seen in the community setting (USA400/CMRSA7 and USA300/CMRSA10), are often identified as hospital-acquired (HA) infections using Infection Prevention and Control (IPC) surveillance definitions. This study examined the demographics and healthcare risk factors of patients with HA-MRSA to help understand if community MRSA clones are from a source internal or external to the hospital setting. Despite USA300/CMRSA10 being the predominant clone in Alberta, hospital clones (USA100/CMRSA2) still dominated in the acute care setting. In the Alberta hospitalized population, patients with USA400/CMRSA7 and USA300/CMRSA10 clones were significantly younger, had fewer comorbidities, and a greater proportion had none or ambulatory care-only healthcare exposure. These findings suggest that there are two distinct populations of HA-MRSA patients, and the patients with USA400/CMRSA7 and USA300/CMRSA10 clones identified in hospital more greatly resemble patients affected by those clones in the community. It is possible that epidemiological assessment overidentifies HA acquisition of MRSA in patients unscreened for MRSA on admission to acute care.