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Abstract Water is transported into the deep mantle by subducting slabs, playing important roles in mantle dynamics and evolution. An aluminous hydrous mineral, phase δ with a main component of AlOOH, has been considered an important water carrier in the lower mantle. Recent studies reported that SiO2 stishovite can accommodate weight percent levels of water, indicating another important water carrier in the lower mantle. However, which mineral can mainly carry water is not clear yet. Recent hydrous phase relation studies reported that stishovite is depleted in alumina when coexisting with hydrous phase δ, in which water content of stishovite was not investigated. In this study, we investigated hydrogen partitioning between stishovite and hydrous phase δ at 24–28 GPa and 1000–1200 °C by means of Kawai-type multi-anvil press in combination with Fourier-transform infrared spectroscopy at ambient conditions on recovered samples. Fourier-transform infrared spectra of recovered stishovites showed that water contents of stishovite coexisting with hydrous phase δ were limited to up to ~ 500 ppm. This indicates that coexisting hydrous phase δ causes not only depletion in alumina but also in hydrogen in stishovite and therefore mainly transports water in a cold subducting slab. Once hydrous phase δ becomes thermally unstable, alumina and water contents in silica minerals are increased by the chemical reaction between SiO2 and AlOOH, and aluminous silica minerals such as stishovite and CaCl2-type phase will be a main water carrier in the lower mantle. Presence of small-scale seismic scatterers observed around 1900 km depth, which was considered to be caused by a transition from almost pure SiO2 stishovite to CaCl2-type phase, might also be able to be explained by the phase transition of stishovite coexisting with hydrous phase δ.

Abstract The role of stishovite in transporting water in subducting slabs has been a subject of debate for several decades. Here we investigated stishovite's water solubility and its potential role in water transportation as a function of temperature from 1300 to 2100°C at 22 GPa. Under water‐saturated conditions, high‐quality, Al‐free stishovite single crystals were synthesized with multi‐anvil press, and their water contents were measured using infrared spectroscopy. The H2O solubility in stishovite increases from 128(20) to 521(47) wt. ppm with increasing temperature from 1300 to 1700°C and decreased to 145(26) wt. ppm at 2100°C. The maximum H2O content was about seven times larger than earlier high‐temperature multi‐anvil studies but significantly lower than recent laser‐heated diamond anvil cell and low‐temperature multi‐anvil studies. We suggest that Al‐free stishovite may not be a significant H2O carrier in subducting slabs, at least at the topmost lower mantle corresponding to our experimental conditions.

Abstract The stishovite to post‐stishovite phase transition may modify the scattering of seismic waves by stishovite‐bearing rocks in the Earth's lower mantle. A series of continuous compression experiments on sintered polycrystalline stishovite was performed to study the effect of stress on the phase transition. The experimental results show that the phase transition shifts to lower pressures as the magnitude of deviatoric stress increases. Our results further show that the bulk modulus of sintered polycrystalline stishovite differs from that derived from single crystal measurements and decreases at the phase transition. In cold regions, such as subducted slabs, stresses may accumulate and shift the phase transition to a shallower depth. In hot regions with less stress, such as rising plumes, the phase transition is shifted to a greater depth. In addition, the phase transition may have varying seismic signatures depending on the behavior of the grain boundaries in mantle rocks and the micro‐stresses present in neighboring grains.

Single-crystal Brillouin scattering measurements are important for interpreting seismic velocities within the Earth and other planetary interiors. These measurements are rare, however, at temperatures above 1000 K, due to the fact that the transparent samples cannot be heated by common laser heating systems operating at a wavelength on the order of 1 μm. Here we present Brillouin scattering data on pyrope collected at pressures up to 23.8 GPa and temperatures between 850 and 1900 K using a novel CO2 laser heating system confined in either a flexible hollow silica waveguide or an articulated arm with mirrors mounted in each junction to direct the laser to the exit point. Pyrope has been chosen because it has been extensively studied at high pressures and moderate temperatures and therefore it is an excellent sample for bench-marking the CO2 laser heating system. The new high-temperature velocity data collected in this study allow the room pressure thermal parameters of pyrope to be constrained more tightly, resulting in values that reproduce the temperature dependence of the unit-cell volume of pyrope measured in recent studies at ambient pressure. Aggregate wave velocities of pyrope calculated along an adiabat using the thermoelastic parameters determined in this study are larger than those obtained using published values, implying that velocities for many mantle components may be underestimated at mantle temperatures because high temperature experimental data are lacking. [ABSTRACT FROM AUTHOR]

Hydrogen may be recycled into the Earth's lower mantle by subduction and stabilized in solid solutions between phase H (MgSiO4H2), δ-AlOOH, ε-FeOOH, and SiO2 post-stishovite. In high-pressure oxyhydroxide phases, hydrogen is incorporated following the typical (OHO) sequence, adopting the asymmetric configuration O-H⋯O that evolves into a symmetric disordered state upon compression. Moreover, these iron-bearing aluminum oxyhydroxides [δ-(Al,Fe)OOH] present a structural phase transition from P21nm to Pnnm as pressure increases. Here, the single-crystal elasticity of the P21nm phase of δ-(Al0.97Fe0.03)OOH has been experimentally determined across the P21nm→Pnnm transition up to 7.94(2) GPa by simultaneous single-crystal X-ray diffraction (XRD) and Brillouin scattering at high pressures. The transition appears to be continuous, and it can be described with a second-, fourth-, and sixth-order terms Landau potential. Our results reveal an enhanced unit-cell volume compressibility, which is linked to an increase of the b- and a-axes linear compressibility in the P21nm phase of δ-(Al0.97Fe0.03)OOH prior to the transition. In addition, we observed the presence of elastic softening in the P21nm phase that mostly impacts the elastic stiffness coefficients c12, c22, and c23. The observed elastic anomalies cause a significant change in the pressure dependence of the adiabatic bulk modulus (KS). These results provide a better understanding of the relation between elasticity, P21nm→Pnnm structural phase transition, and hydrogen dynamics in δ-(Al0.97Fe0.03)OOH, which may be applied to other O-H⋯O-bettring phases. [ABSTRACT FROM AUTHOR]

The full spectrum of SARS-CoV-2-infected patients has not yet been defined. This study aimed to evaluate which parameters derived from CT, inflammatory, and hormonal markers could explain the clinical variability of COVID-19. We performed a retrospective study including SARS-CoV-2–infected patients hospitalized from March 2020 to May 2021 at the Umberto I Polyclinic of Rome. Patients were divided into four groups according to the degree of respiratory failure. Routine laboratory examinations, BMI, liver steatosis indices, liver CT attenuation, ferritin, and IGF-1 serum levels were assessed and correlated with severity. Analysis of variance between groups showed that patients with worse prognoses had higher BMI and ferritin levels, but lower liver density, albumin, GH, and IGF-1. ROC analysis confirmed the prognostic accuracy of IGF-1 in discriminating between patients who experienced death/severe respiratory failure and those who did not (AUC 0.688, CI: 0.587 to 0.789, p < 0.001). A multivariate analysis considering the degrees of severity of the disease as the dependent variable and ferritin, liver density, and the standard deviation score of IGF-1 as regressors showed that all three parameters were significant predictors. Ferritin, IGF-1, and liver steatosis account for the increased risk of poor prognosis in COVID-19 patients with obesity.

During the fourth year of Amy Phillips' teaching assistantship in the spring semester of 2008, she was asked to teach a 300-level advanced writing course in which she was given the creative freedom to design the syllabus, choose the textbooks, craft all assignments, and organize the course content. However, there was one stipulation: the course, which was cross-listed with the Women and Gender Studies program, had to focus on the general topic of women and gender. In order to begin this task of designing her first 300-level writing course, within the requirements provided, Phillips used several of the strategies for course design offered by Linda B. Nilson in her book, "Teaching at Its Best: A Research-Based Resource for College Instructors." Firstly, she adopted a "course design by objectives" approach, which advocates "starting the course design process with what you want your students to be able to do by the end of the course" (Nilson 17). With respect to composition, Phillips wanted the culminating assignment in the class, or ultimate learning objective, to be a literary research paper (approximately 15-17 pages in length) that allowed each student to engage with a topic of his or her choice and design. Having established the larger goals of the course, she considered the following questions: How can one design an advanced writing course that enables students to achieve both community goals--in which all students learn and use the same writing skills--and individual goals--in which each student can apply those writing skills to a project that allows him or her to explore personal interests? How can one best use class time to create a foundation of writing skills and gender-based content while allowing students to develop independent critical thinking and writing skills? How can one successfully devote equal time to developing the topic of gender while focusing on the necessary advanced skills of composition, research, argument, and organization? In this essay Phillips outlines the manner in which she designed a course with such a specific focus on both content and rhetoric; discusses the structure of the course itself; and addresses the necessary recommendations she would make if given the opportunity to teach this course again.

Background and study aims The adherence to and knowledge of physicians about colorectal cancer (CRC) screening and surveillance guidelines is still suboptimal, threatening the effectiveness of CRC screening. This study assessed the usefulness of a mobile decision support system (MDSS) to improve physician ability to recommend proper timing of and intervals for CRC screening and surveillance. Patients and methods This was a binational, single-blinded, randomized clinical trial including gastroenterologists and colorectal surgeons from Argentina and Uruguay. The specialists were invited to respond to a questionnaire with 10 CRC screening and surveillance clinical scenarios, randomized into two groups, with and without access to a dedicated app (CaPtyVa). The main outcome measure was the proportion of physicians correctly solving at least 60 % of the clinical cases according to local guidelines. Results A total of 213 physicians were included. The proportion of physicians responding correctly at least 60 % of the vignettes was higher in the app group as compared to the control group (90 % versus 56 %) (relative risk [RR] 1.6 95 % confidence interval [CI] 1.34–1.91). The performance was also higher in the app group for both vignette categories: CRC screening (93 % vs 75 % RR 1.24, 95 %CI 1.01–1.40) and surveillance (85 % vs 47 % RR 1.81 95 %CI 1.46–2.22), respectively. Physicians considered the app easy to use and of great utility in daily practice. Conclusions A MDSS was shown to be a useful tool that improved specialist performance in solving CRC screening and surveillance clinical scenarios. Its implementation in daily practice may facilitate the adherence of physicians to CRC screening and surveillance guidelines.

Introduction: Different developmental and environmental vulnerability conditions can influence violent behavior in young people. Objectives: To describe the characteristics of young males who were convicted of murder or attempted murder in the province of Buenos Aires, based on indicators of maturity, impulsivity, and socio-family vulnerability. Materials and Methods: Descriptive and exploratory study. The sample consisted of 195 young men (mean: 16.8 years) imprisoned in reformatory institutions of the Province of Buenos Aires, Argentina, as they were convicted of murder (n=130), repeated murder (n=15), or attempted murder (n=50). Self and hetero-informed instruments, and professional assessment scales were used, namely: the Consideration of Future Consequences Scale (CFC); the Psychosocial Maturity Inventory (PSM); the Weinberg Adjustment Inventory (WAI); the Resistance to Peer Influence Questionnaire (RPIQ); the Psychopathy Checklist: Youth Version (PCL:YV); the Inventory of Callous Unemotional Traits (ICU), and the Barrat Impulsiveness Scale version 11 (BIS-11). Results: The distribution of the total BIS 11 and the PSM Individual Adaptation were normal (mean: 62.33 and 6.38, respectively). The mean of the total PCL:YV was 25.87. In 32.8% of the cases a first degree relative was also imprisoned. “Impulsive” and “Nonimpulsive” clusters were empirically established. Conclusions: The participants’ profile is characterized by several psychological and socio-family vulnerabilities that should be targeted in preventive interventions aimed at preventing violent recidivism.

BackgroundThe neutrophil-to-lymphocyte ratio (NLR) has been investigated in many autoimmune conditions as a biomarker of inflammation and/or disease activity. The role of NLR in AQP4-IgG-positive neuromyelitis optica spectrum disorders (NMOSD) is far from clear. In this study, NLR was evaluated in patients with AQP4-IgG-positive NMOSD at disease onset and its prognostic impact was subsequently assessed.MethodsIn this multicenter study, we retrospectively included all recent/newly diagnosed treatment-naïve patients with AQP4-IgG-positive NMOSD (n=90) from three different countries in Latin America (LATAM): Argentina, Ecuador, and Mexico. NLR was compared between AQP4-IgG-positive NMOSD and healthy controls (HC, n = 365). Demographic, clinical, paraclinical (including imaging), and prognostic data at 12 and 24 months were also evaluated. Multivariate regression analysis was used to describe and identify independent associations between the log-transformed NLR and clinical (relapses and EDSS) and imaging (new/enlarging and/or contrast-enhancing MRI lesions) outcomes.ResultsNLR was higher in NMOSD patients during the first attack compared with HC (2.9 ± 1.6 vs 1.8 ± 0.6; p

The role of stishovite in transporting water in subducting slabs has been a subject of debate for several decades. Here we investigated stishovite's water solubility and its potential role in water transportation as a function of temperature from 1300 to 2100°C at 22 GPa. Under water‐saturated conditions, high‐quality, Al‐free stishovite single crystals were synthesized with multi‐anvil press, and their water contents were measured using infrared spectroscopy. The H2O solubility in stishovite increases from 128(20) to 521(47) wt. ppm with increasing temperature from 1300 to 1700°C and decreased to 145(26) wt. ppm at 2100°C. The maximum H2O content was about seven times larger than earlier high‐temperature multi‐anvil studies but significantly lower than recent laser‐heated diamond anvil cell and low‐temperature multi‐anvil studies. We suggest that Al‐free stishovite may not be a significant H2O carrier in subducting slabs, at least at the topmost lower mantle corresponding to our experimental conditions. Plain Language Summary: Stishovite is a high‐pressure phase of silicon dioxide (SiO2). It was recently reported that stishovite could contain a substantial amount of water based on diamond anvil cell experiments and, consequently, transport water into the lower mantle through subducting slabs. However, the water contents in their samples lack precise constrain due to the limited size of the recovered crystals, making them inaccessible for measurements using reliable FTIR spectroscopy or secondary‐ion mass spectroscopy. To settle this debate, we produced high‐quality single crystals of stishovite under water‐saturated conditions at high pressures and temperatures and measured their water contents using infrared spectroscopy. We discovered that stishovite contained only several hundred ppm of water under conditions at the top of the lower mantle. Therefore, it is likely that stishovite does not contain much water in the upper region of the lower mantle and does not transport water into the deep lower mantle. Key Points: H2O content in Al‐free stishovite increases with temperature up to 1700°C and decreases beyond this temperatureThe maximum H2O content in Al‐free stishovite at 22 GPa is 521 (47) wt. ppmAl‐free stishovite cannot be the major H2O carrier at least up to the uppermost lower mantle conditions [ABSTRACT FROM AUTHOR]

A literary criticism of the book "As I Lay Dying" by William Faulkner is presented. Topics include the debate on narrational inconsistencies, proposed solutions such as interior monologues and a unifying narrative consciousness, and the author's argument introducing the concept of an Implied Editor as a third plane of existence responsible for mediating and recording the character-narrators' thoughts.