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The earth is thought to have gone through complex physicochemical changes during the accretion and magma ocean stages. To better understand this evolution process at the fundamental level, we investigate the behavior of a bulk earth melt system by simulating the composition Fe 35.7 Mg 19.0 Si 15.2 O 30.2 (in wt%) at high pressure. A deep neural network potential trained by first-principles data can enable accurate molecular dynamics simulation of large supercells that greatly enhances sampling for reliable evaluation of elemental partitioning. Our simulated system undergoes a phase separation in which the four elements clump together to different extents into two major domains. Based on the coordination and space-decomposition analyses, the inferred composition at 3000 K and 29.1 GPa contains 96.2, 0.1, 1.9 and 1.7 wt% of Fe, Mg, Si, and O, respectively, for the one domain and the corresponding elemental proportions are 3.0, 29.7, 22.0, and 45.3 wt% for the other domain. The predicted segregation thus leads to the formation of an iron-rich phase which corresponds to the metallic core and a magma ocean phase which corresponds to the silicate mantle. The metallic domain incorporates more silicon and more oxygen whereas the magma ocean domain gains more iron oxides at higher temperatures. Our predicted compositions compare favorably with those derived from experimental work for the equilibrium state metal and silicate reacting under high-pressure conditions., (© 2024. The Author(s).)

Background: Dermatophytosis, commonly known as tinea, poses a significant public health concern worldwide, especially in environments with poor hygiene and overcrowding, such as prisons. Despite its prevalence and impact on quality of life, there is a lack of research on the knowledge and hygiene practices regarding dermatophytosis among prisoners, particularly in Nepal., Objective: The study aimed to assess prisoners' knowledge, hygiene practice and infection status regarding dermatophytosis in Central Prison, Nepal., Methods: A descriptive cross-sectional study with a sample size of 184 respondents was designed to collect data using a validated pre-tested questionnaire from September 2023 to January 2024. The collected data was then analyzed using IBM SPSS version 21. Knowledge and hygiene practices were measured on an eight and 11-point scale and rated as poor (≤4) and sound (>4), bad (≤6), and good (>6), respectively. Summary data were presented by descriptive, while Chi-square and logistic regression were used for inferential statistics at p  < 0.05., Results: The findings revealed moderate knowledge among prisoners regarding dermatophytosis, with significant gaps in understanding its spread and prevention. While most prisoners recognized the importance of treatment, there were misconceptions about the inevitability of contracting dermatophytosis and the role of personal hygiene., Conclusion: Despite good knowledge levels, adherence to recommended hygiene practices was suboptimal, highlighting the need for targeted interventions. The study underscores the importance of addressing knowledge gaps, changing attitudes, and promoting hygienic practices to mitigate the burden of dermatophytosis among prisoners., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Dhakal, Shrestha, Shah, Rijal, Karki, Pangeni, Bhatta, Mehta, Thapa, Zeeshan, Sah, Luna, Bonilla-Aldana and Rodriguez-Morales.)

Background: Painful diabetic peripheral neuropathy is one of the frequent presenting complaints in diabetes and endocrine clinics. Our main objective was to compare effectiveness of three commonly prescribed drugs: amitriptyline, pregabalin and duloxetine for treatment of painful diabetic peripheral neuropathy., Methods: This was a comparative, prospective, observational study conducted among 99 diabetic patients with painful diabetic peripheral neuropathy having numeric rating pain scale ≥ 4. Thirty-three patients in each group were consecutively prescribed amitriptyline, pregabalin and duloxetine in lower dose (10mg/75mg/20mg) for first two weeks to gradually up titrate to higher dose (25mg/150mg/30mg) as per pain response for total duration of eight weeks., Results: At the end of eight weeks, 84.9% in amitriptyline, 78.7% in pregabalin and 60.6% in duloxetine group had adequate pain reduction in form of mild or no pain. Among total patients, 42.5% patients had severe pain at baseline that decreased to 5% by the end of our study. Out of three drugs, 45.5% patients in amitriptyline group had complete resolution of pain as compared to 24.2% in pregabalin and 18.2% in duloxetine group (p value 0.05). Drowsiness (42.4%), dizziness (21.2%) and dry mouth (21.2%) were the commonest side effects among total participants in our study., Conclusions: Amitriptyline, pregabalin and duloxetine were all associated with adequate pain reduction among patients of painful diabetic peripheral neuropathy in our study, however, amitriptyline had more favorable findings with tolerable side effects.

Objectives: Post cholecystectomy pain syndrome can cause significant distress, impairs quality of life and exacerbations often result in emergency visits. Poorly controlled postoperative pain is a recognized cause of persistent postsurgical pain. Abdominal myofascial pain syndrome is an underdiagnosed cause of persistent pain in this cohort. The objective was to estimate the incidence of poorly controlled postoperative pain in the first 48 h after surgery and the likelihood of developing persistent pain at 12 months., Methods: The patients undergoing laparoscopic cholecystectomy at a tertiary unit were consented for participation in a prospective service evaluation. A telephone review was performed at three, six and twelve months after surgery. Incidence of poorly controlled pain in the first 48 h after surgery was assessed. Patients with persistent pain were referred to the pain clinic., Results: Over a six-month period, 200 patients were assessed. Eleven patients were excluded (5.5 %). Twelve patients were lost to follow-up (6.6 %, 12/189). Patient satisfaction with acute postoperative pain management was low in 40 % (76/189). Poorly controlled postoperative pain was reported by 36 % (68/189) of patients. Incidence of persistent pain was 29 % (54/189) at 12 months post-surgery. Over half of patients with persistent pain (63 %, 34/54) reported poorly controlled postoperative pain. A somatic source was diagnosed in 54 % (29/54) with post cholecystectomy pain syndrome., Conclusions: Poorly controlled postoperative pain was reported by a third of patients. Persistent pain was present in 29 % at twelve months post-surgery. Abdominal myofascial pain syndrome should be considered as a differential diagnosis in post cholecystectomy pain syndrome., (© 2023 the author(s), published by De Gruyter, Berlin/Boston.)

The viscosity of magma plays a crucial role in the dynamics of the Earth: from the crystallization of a magma ocean during its initial stages to modern-day volcanic processes. However, the pressure-dependence behavior of viscosity at high pressure remains controversial. In this study, we report the results of first-principles molecular dynamics simulations of basaltic melt to show that the melt viscosity increases upon compression along each isotherm for the entire lower mantle after showing minima at ~6 GPa. However, elevated temperatures of the magma ocean translate to a narrow range of viscosity, i.e., 0.01-0.03 Pa.s. This low viscosity implies that the crystallization of the magma ocean could be complete within a few million years. These results also suggest that the crystallization of the magma ocean is likely to be fractional, thus supporting the hypothesis that present-day mantle heterogeneities could have been generated during the early crystallization of the primitive mantle., (© 2022. The Author(s).)

Water (H 2 O) as one of the most abundant fluids present in Earth plays crucial role in the generation and transport of magmas in the interior. Though hydrous silicate melts have been studied extensively, the experimental data are confined to relatively low pressures and the computational results are still rare. Moreover, these studies imply large differences in the way water influences the physical properties of silicate magmas, such as density and electrical conductivity. Here, we investigate the equation of state, speciation, and transport properties of water dissolved in Mg 1-x Fe x SiO 3 and Mg 2(1-x) Fe 2x SiO 4 melts (for x = 0 and 0.25) as well as in its bulk (pure) fluid state over the entire mantle pressure regime at 2000-4000 K using first-principles molecular dynamics. The simulation results allow us to constrain the partial molar volume of the water component in melts along with the molar volume of pure water. The predicted volume of silicate melt + water solution is negative at low pressures and becomes almost zero above 15 GPa. Consequently, the hydrous component tends to lower the melt density to similar extent over much of the mantle pressure regime irrespective of composition. Our results also show that hydrogen diffuses fast in silicate melts and enhances the melt electrical conductivity in a way that differs from electrical conduction in the bulk water. The speciation of the water component varies considerably from the bulk water structure as well. Water is dissolved in melts mostly as hydroxyls at low pressure and as -O-H-O-, -O-H-O-H- and other extended species with increasing pressure. On the other hand, the pure water behaves as a molecular fluid below 15 GPa, gradually becoming a dissociated fluid with further compression. On the basis of modeled density and conductivity results, we suggest that partial melts containing a few percent of water may be gravitationally trapped both above and below the upper mantle-transition region. Moreover, such hydrous melts can give rise to detectable electrical conductance by means of electromagnetic sounding observations.

Cardiovascular diseases (CVDs) account for the largest proportion of all deaths in Nepal (30%). Studies report that CVDs often begin with modifiable lifestyle risk behaviours established during adolescence which manifest later. This study aimed to measure changes in the five mortality-associated CVD risk behaviours (i.e., consumption of tobacco, alcohol, and junk food, physical inactivity, and stress among school adolescents) using an integrative intervention with the experiential learning approach. The study was carried out for 24 weeks (25 credit hours) among 4,225 students from grades 8 to 10 in community schools in seven provinces in Nepal. Pre- and post-intervention in-class self-reported surveys were conducted for assessing change in the students' aggregate risk behaviours. These percent changes were assessed through bivariate analysis. Key-informant interviews of teachers were conducted to assess their perceptions of the effectiveness of the intervention. At 24 weeks, the percentages of students reporting consumption of cigarettes and smokeless tobacco declined by 25% and 28% respectively, consumption of alcohol declined by 29%, consumption of instant noodles by 11%, and consumption of coke by 43%. The proportion of students reporting 'going to school by foot every day' increased by 11%, and those 'exercising until they sweat' increased by 29%. The percentage of students who reported feeling that their 'life has been running as desired' increased by 16%. Key-informant interviews of the teachers revealed that the intervention had contributed to improved motivation, knowledge, and attitude among students towards mitigating the risk behaviours. These interviews also recommended continuation of the intervention. The sample in this study has shown positive changes in school adolescents' self-reported aggregate CVD risk behaviours using the experiential learning approach. However, further research should be conducted to explore the sustainability and scaling of these learning modules through the existing non-communicable disease (NCD) school curriculum activities in Nepal., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2020 The Author(s).)

Magma oceans were once ubiquitous in the early solar system, setting up the initial conditions for different evolutionary paths of planetary bodies. In particular, the redox conditions of magma oceans may have profound influence on the redox state of subsequently formed mantles and the overlying atmospheres. The relevant redox buffering reactions, however, remain poorly constrained. Using first-principles simulations combined with thermodynamic modeling, we show that magma oceans of Earth, Mars, and the Moon are likely characterized with a vertical gradient in oxygen fugacity with deeper magma oceans invoking more oxidizing surface conditions. This redox zonation may be the major cause for the Earth's upper mantle being more oxidized than Mars' and the Moon's. These contrasting redox profiles also suggest that Earth's early atmosphere was dominated by CO 2 and H 2 O, in contrast to those enriched in H 2 O and H 2 for Mars, and H 2 and CO for the Moon.

Seismic observations suggest that the uppermost region of Earth's liquid outer core is buoyant, with slower velocities than the bulk outer core. One possible mechanism for the formation of a stably stratified layer is immiscibility in molten iron alloy systems, which has yet to be demonstrated at core pressures. We find immiscibility between liquid Fe-Si and Fe-Si-O persisting to at least 140 GPa through a combination of laser-heated diamond-anvil cell experiments and first-principles molecular dynamics simulations. High-pressure immiscibility in the Fe-Si-O system may explain a stratified layer atop the outer core, complicate differentiation and evolution of the deep Earth, and affect the structure and intensity of Earth's magnetic field. Our results support silicon and oxygen as coexisting light elements in the core and suggest that [Formula: see text] does not crystallize out of molten Fe-Si-O at the core-mantle boundary., Competing Interests: The authors declare no conflict of interest.

Carbon dioxide, generally considered as the second most abundant volatile component in silicate magmas, is expected to significantly influence various melt properties. In particular, our knowledge about its dynamical effects is lacking over most of Earth's mantle pressure regime. Here, we report the first-principles molecular dynamics results on the transport properties of carbonated MgSiO 3 liquid under conditions of mantle relevance. They show that dissolved CO 2 systematically enhances the diffusion rates of all elements and lowers the melt viscosity on average by factors of 1.5 to 3 over the pressure range considered. It is remarkable that CO 2 has very little or no influence on the electrical conductivity of the silicate melt under most conditions. Simulations also predict anomalous dynamical behavior, increasing diffusivity and conductivity and decreasing viscosity with compression in the low-pressure regime. This anomaly and the concomitant increase of pressure and temperature with depth together make these transport coefficients vary modestly over extended portions of the mantle regime. It is possible that the melt electrical conductivity under conditions corresponding to the 410- and 660-km seismic discontinuities is at a detectable level by electromagnetic sounding observation. In addition, the low melt viscosity values of 0.2 to 0.5 Pa⋅s at these depths and near the core-mantle boundary may imply high mobility of possible melts in these regions.

Knowledge about the incorporation and role of carbon in silicate magmas is crucial for our understanding of the deep mantle processes. CO 2 bearing silicate melting and its relevance in the upper mantle regime have been extensively explored. Here we report first-principles molecular dynamics simulations of MgSiO 3 melt containing carbon in three distinct oxidation states - CO 2 , CO, and C at conditions relevant for the whole mantle. Our results show that at low pressures up to 15 GPa, the carbon dioxide speciation is dominated by molecular form and carbonate ions. At higher pressures, the dominant species are silicon-polyhedral bound carbonates, tetrahedral coordination, and polymerized di-carbonates. Our results also indicate that CO 2 component remains soluble in the melt at high pressures and the solution is nearly ideal. However, the elemental carbon and CO components show clustering of carbon atoms in the melt at high pressures, hinting towards possible exsolution of carbon from silicate melt at reduced oxygen contents. Although carbon lowers the melt density, the effect is modest at high pressures. Hence, it is likely that silicate melt above and below the mantle transition zone, and atop the core-mantle boundary could efficiently sequester significant amounts of carbon without being gravitationally unstable.

The low/ultralow-velocity zones in the Earth's mantle can be explained by the presence of partial melting, critically depending on density contrast between the melt and surrounding solid mantle. Here, first-principles molecular dynamics simulations of (Mg, Fe) O ferropericlase in the solid and liquid states show that their densities increasingly approach each other as pressure increases. The isochemical density difference between them diminishes from 0.78 (±0.7) g/cm 3 at zero pressure (3000 K) to 0.16 (±0.04) g/cm 3 at 135 GPa (4000 K) for pure and alloyed compositions containing up to 25% iron. The simulations also predict a high-spin to low-spin transition of iron in the liquid ferropericlase gradually occurring over a pressure interval centered at 55 GPa (4000 K) accompanied by a density increase of 0.14 (±0.02) g/cm 3 . Temperature tends to widen the transition to higher pressure. The estimated iron partition coefficient between the solid and liquid ferropericlase varies from 0.3 to 0.6 over the pressure range of 23 to 135 GPa. Based on these results, an excess of as low as 5% iron dissolved in the liquid could cause the solid-liquid density crossover at conditions of the lowermost mantle.

The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our results suggest that as pressure increases, all types of coordination between major cations and anions strongly increase, and the water speciation changes from isolated species to extended forms. These structural changes are responsible for rapid initial melt densification on compression thereby making these basaltic melts possibly buoyantly stable at one or more depths. Our finding that the melt-water system is ideal (nearly zero volume of mixing) and miscible (negative enthalpy of mixing) over most of the mantle conditions strengthens the idea of potential water enrichment of deep-mantle melts and early magma ocean.

Introduction: We are increasingly noticing isolated left axis deviation (LAD) in electrocardiogram in younger people with diabetes without obvious heart disease and association of LAD with glucose intolerance has not been explicitly raised before. We planned a study of ambulatory adults with borderline (0° to -30°) and moderate-to-marked (<-30° to -90°) LAD looking into their possible association with glucose intolerance with fasting plasma glucose (FPG)≥100 mg/dL., Methods: We consecutively enrolled adults aged 30 or more, with electrocardiogram normal duration QRS axis between 0° to -90°, without cardiac symptoms, not on any medication, attending outdoor-clinics for health checkup., Results: Out of 100 participants enrolled, about 90% were aged between 30 and 60 and 47% had borderline and 53% moderate-to-marked LAD. Moderate-to-marked LAD group had higher frequencies of abnormal blood pressure (BP), FPG, and lipids than borderline LAD group even after conditioning effects of age and sex (p≤0.03) and of FPG after conditioning effects of BP (p=0.02). The frequencies of glucose intolerance were 48.9% even in borderline LAD with 84.9% in moderate-to-marked LAD group. In moderate-to-marked LAD group mean values of BP, FPG, and lipid profiles were higher (p<0.001) and abnormal. In borderline LAD group though mean BP and lipid values were normal, FPG was impaired., Conclusions: Impaired mean FPG values and high frequencies of glucose intolerance in both borderline LAD group with normal BP and moderate-to-marked LAD group with conditioning of effects of BP in relatively younger ambulatory adults without cardiac symptoms indicate possible association between LAD and glucose intolerance.

Introduction: The gut mucosa in portal hypertension is the seat of microcirculatory changes that compromise its integrity and increase its susceptibility to damage. The mucosal changes in portal hypertension may require pharmacological, directed endoscopic or portal decompressive therapy. The objective of the study is to find out various upper gastrointestinal tract endoscopic findings in patients of portal hypertension., Methods: A prospective, cross-sectional, observational study of sixty patients of portal hypertension was conducted from June to October 2009. The esophagus, stomach and upper duodenum was visualized for any changes, especially by taking the tip of the instrument close to the mucosa., Results: Out of total, 60, 47 (78.3%) cases were cirrhotic and 13 (21.7%) cases were non-cirrhotic portal hypertension. The most frequent upper GI endoscopic finding was esophageal varices 56 (98.3%) followed by gastropathy 49 (81.6%), gastric hyperemia 19 (31.6%), duodenal hyperemia and erosive gastritis 16 (26.6% in each) and gastric varices 12 (20%). Esophageal varices were equally prevalent among cirrhotic and non cirrhotic portal hypertensive patients, 46 out of 47 (97.9%) and 13 out of 13 (100%) respectively. Gastropathy was more prevalent in cirrhotic patients with 87.2% vs. 75% in NCPF followed by 40% in EHO. However, duodenal ulcers were seen only in EHO 12.5%. Erosive gastritis was more prevalent in EHO (75%) followed by NCPF (60%), however, it was less frequent in cirrhotic portal hypertension (14.8%)., Conclusions: The most common upper GI endoscopic finding in portal hypertensive patients were found to be esophageal varices followed by gastropathy, peptic ulcer disease (gastric and duodenal hyperemia, chronic gastritis, erosive gastritis, gastric ulcer and duodenal ulcer).

First-principles molecular dynamics simulations show that water (8.25 wt%) dramatically affects the transport properties of SiO2 liquid increasing the diffusivity and decreasing the viscosity by an order of magnitude. At 3000 K, the diffusivity of Si, O, and H, and the viscosity vary anomalously with pressure. Highly mobile protons make the hydrous liquid a potential superionic conductor. The predicted dynamical changes are associated with structural depolymerization and water speciation, which changes from being dominated by hydroxyls at low pressure to extended structures at high pressure.

We combine first-principles calculations of forces with the direct nonequilibrium molecular dynamics method to determine the lattice thermal conductivity k of periclase (MgO) up to conditions representative of the Earth's core-mantle boundary (136 GPa, 4100 K). We predict the logarithmic density derivative a=(∂ln k/∂ln ρ)(T)=4.6±1.2 and that k=20±5  Wm(-1) K(-1) at the core-mantle boundary, while also finding good agreement with extant experimental data at much lower pressures.

Understanding the chemical and thermal evolution of Earth requires knowledge of transport properties of silicate melts at high pressure and high temperature. Here, first-principles molecular dynamics simulations show that the viscosity of MgSiO3 liquid varies by two orders of magnitude over the mantle pressure regime. Addition of water systematically lowers the viscosity, consistent with enhanced structural depolymerization. The combined effects of pressure and temperature along model geotherms lead to a 10-fold increase in viscosity with depth from the surface to the base of the mantle. Based on these calculations, efficient heat flux from a deep magma ocean may have exceeded the incoming solar flux early in Earth's history.

Glaucoma is the second leading cause of blindness worldwide. Often, the optic nerve head (ONH) glaucomatous damage and ONH changes occur prior to visual field loss and are observable in vivo. Thus, digital image analysis is a promising choice for detecting the onset and/or progression of glaucoma. In this paper, we present a new framework for detecting glaucomatous changes in the ONH of an eye using the method of proper orthogonal decomposition (POD). A baseline topograph subspace was constructed for each eye to describe the structure of the ONH of the eye at a reference/baseline condition using POD. Any glaucomatous changes in the ONH of the eye present during a follow-up exam were estimated by comparing the follow-up ONH topography with its baseline topograph subspace representation. Image correspondence measures of L1-norm and L2 -norm, correlation, and image Euclidean distance (IMED) were used to quantify the ONH changes. An ONH topographic library built from the Louisiana State University Experimental Glaucoma study was used to evaluate the performance of the proposed method. The area under the receiver operating characteristic curves (AUCs) was used to compare the diagnostic performance of the POD-induced parameters with the parameters of the topographic change analysis (TCA) method. The IMED and L2-norm parameters in the POD framework provided the highest AUC of 0.94 at 10 degrees field of imaging and 0.91 at 15 degrees field of imaging compared to the TCA parameters with an AUC of 0.86 and 0.88, respectively. The proposed POD framework captures the instrument measurement variability and inherent structure variability and shows promise for improving our ability to detect glaucomatous change over time in glaucoma management.

Time-varying three-dimensional scattered data representing snapshots of atomic configurations produced by molecular dynamics simulations are not illuminating by themselves; gaining insight into them poses a tremendous challenge. In order to take the advantage of maximal information offered by these simulations, we have proposed an efficient scheme, which integrates various analysis and rendering tasks together in order to support interactive visualization of the data at space-time multiresolution. Additional data produced by various analytical techniques on the fly represent the atomic system under consideration at diverse length- (e.g., nearest neighbor, next-nearest neighbor or beyond) and time- (e.g., instantaneous, finite intervals or overall averages) scales. In particular, the radial distribution functions, coordination environments, clusters and rings are computed and visualized to understand the structural behavior whereas a variety of displacement data and covariance matrices are explored to understand the dynamical behavior. While the spatial distributions of atoms need to be reproduced correctly during rendering, we take the advantage of high flexibility in rendering other attributes because of the lack of their direct physical relevance. A combination of different techniques including animation, color maps, pathlines, different types of glyphs, and graphics hardware accelerated approach is exploited to render the original and extracted data. First-principles molecular dynamics simulation data for liquid systems are used to justify the effectiveness and usefulness of the proposed scheme.

Large-scale molecular dynamics simulations of self-assembled alkanethiol monolayer systems have been carried out using an all-atom model involving a million atoms to investigate their structural properties as a function of temperature, lattice spacing, and molecular chain length. Our simulations show that the alkanethiol chains of 13-carbons tilt from the surface normal by a collective angle of 25 degrees along next-nearest-neighbor direction at 300 K. The tilt structure of 13-carbon alkanethiol system is found to depend strongly on temperature and exhibits hysteresis. At 350 K the 13-carbon alkanethiol system transforms to a disordered phase characterized by small collective tilt angle, flexible tilt direction, and random distribution of backbone planes. The tilt structure also depends on lattice spacing: With increasing lattice spacing a the tilt angle increases rapidly from a nearly zero value at a=4.7 A to as high as 34 degrees at a=5.3 A at 300 K for 13-carbon alkanethiol system. Finally, the effects of the molecular chain length on the tilt structure are significant at high temperatures., ((c) 2004 American Institute of Physics)

We have determined by means of first principles quasiharmonic calculations the elastic constants and acoustic velocities of MgSiO3 perovskite, the most abundant mineral of the Earth's lower mantle (LM), at pertinent pressures and temperatures. Using these results, along with the effects of low concentration iron alloying and the thermoelasticity of the most important secondary LM phase, MgO, we predict the isotropic elastic moduli of likely LM aggregates. Comparison with seismic values extracted from the preliminary reference Earth model indicates that the top of the LM behaves as a typical aggregate of pyrolitic composition, likewise the upper mantle. But systematic deviations that cannot be accounted for by alterations in the geotherm alone develop toward the deep LM. This result could be viewed as evidence in support of radially inhomogeneous LM models.

The individual elastic constants of magnesium oxide (MgO) have been determined throughout Earth's lower mantle (LM) pressure-temperature regime with density functional perturbation theory. It is shown that temperature effects on seismic observables (density, velocities, and anisotropy) are monotonically suppressed with increasing pressure. Therefore, at realistic LM conditions, the isotropic wave velocities of MgO remain comparable to seismic velocities, as previously noticed in athermal high-pressure calculations. Also, the predicted strong pressure-induced anisotropy is preserved toward the bottom of the LM, so lattice-preferred orientations in MgO may contribute substantially to the observed seismic anisotropy in the D" layer.