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This special issue focuses on William Gilmore Simms (1806-70), an antebellum Southern writer who was one of the most prominent literary figures of his time but who for many complicated [...]

William Wordsworth was influenced by a pencil drawing to write a poem that seems to contradict itself. The pencil portrait of Jemima Quillinan by Frank Stone caused Wordsworth to simultaneously consider the power of art to make transitory impressions permanent, while also evoking thoughts of mortality that Wordsworth did not want to consider. The picture made Wordsworth think of Jemima's dead mother, then his awareness of art as a defense against death and time, and finally reminded him of his own death.

Earth's inner core exhibits strong seismic anisotropy, often attributed to the alignment of hexagonal close‐packed iron (hcp‐Fe) alloy crystallites with the Earth's poles. How this alignment developed depends on material properties of the alloy and is important to our understanding of the core's crystallization history and active geodynamical forcing. Previous studies suggested that hcp‐Fe is weak under deep Earth conditions but did not investigate the effects of the lighter elements known to be part of the inner core alloy. Here, we present results from radial X‐ray diffraction experiments in a diamond anvil cell that constrain the strength and deformation properties of iron‐nickel‐silicon (Fe–Ni–Si) alloys up to 60 GPa. We also show the results of laser heating to 1650 K to evaluate the effect of temperature. Observed alloy textures suggest different relative activities of the various hcp deformation mechanisms compared to pure Fe, but these textures could still account for the theorized polar alignment. Fe–Ni–Si alloys are mechanically stronger than Fe and Fe–Ni; extrapolated to inner core conditions, Si‐bearing alloys may be more than an order of magnitude stronger. This enhanced strength proportionally reduces the effectivity of dislocation creep as a deformation mechanism, which may suggest that texture developed during crystallization rather than as the result of postsolidification plastic flow. Plain Language Summary: The inner core is a Moon‐sized ball of solid metal at the very center of the Earth. Vibrations from earthquakes move faster through the inner core if they travel parallel to Earth's axis (the line between the North and South Poles) than if they travel parallel to the Equator. This probably means that the grains of metal in the inner core are themselves aligned with Earth's axis. Previous studies determined that this alignment likely happened after the inner core had formed, but those experiments were done on pure iron, whereas the inner core is mostly iron but also contains other elements. We did experiments at high pressures and temperatures on a more realistic core metal containing iron, nickel, and silicon. We found that this metal would be much stronger than pure iron at inner core pressures and temperatures; it is still possible for it to produce a north‐south alignment, but it is much more difficult for it to do so. This could mean that the alignment occurred while the inner core was forming (rather than afterward), which might change how we think about the forces present in the deep Earth today. Key Points: The inner core's seismic anisotropy can be explained by crystallographic alignment of a hexagonal close‐packed iron‐rich alloySample textures suggest that silicon‐bearing alloy deformation may be dominated by pyramidal and basal slip at low and high T, respectivelySilicon‐bearing alloys are stronger (harder to deform) at inner core conditions than pure iron and iron–nickel alloys [ABSTRACT FROM AUTHOR]

Nitrogen, the most abundant element in Earth's atmosphere, is also a primary component of solid nitride minerals found in meteorites and on Earth's surface. If they remain stable to high pressures and temperatures, these nitrides may also be important reservoirs of nitrogen in planetary interiors. We used synchrotron X‐ray diffraction to measure the thermal equation of state and phase stability of titanium nitride (TiN) in a laser‐heated diamond anvil cell at pressures up to ∼70 GPa and temperatures up to ∼2,500 K. TiN maintains the cubic B1 (NaCl‐type) crystal structure over the entire pressure and temperature range explored. It has K0 = 274 (4) GPa, K0′ = 3.9 (2), and γ0 = 1.39 (4) for a fixed V0 = 76.516 (30) Å3 (based on experimental measurements), q = 1, and θ0 = 579 K. Additionally, we collected Raman spectra of TiN up to ∼60 GPa, where we find that the transverse acoustic (TA), longitudinal acoustic (LA), and transverse optical phonon modes exhibit mode Grüneisen parameters of 1.66(17), 0.54(15), and 0.93 (4), respectively. Based on our equation of state, TiN has a density of ∼5.6–6.4 g/cm3 at Earth's lower mantle conditions, significantly more dense than both the mantle of the Earth and the estimated densities of the mantles of other terrestrial planets, but less dense than planetary cores. We find that TiN remains stable against physical decomposition at the pressures and temperatures found within Earth's mantle, making it a plausible reservoir for deep planetary nitrogen if chemical conditions allow its formation. Plain Language Summary: Understanding the incorporation of nitrogen into Earth's interior could account for discrepancies in Earth's nitrogen budget. Solid nitride materials have been suggested to store nitrogen in the mantle and/or core. We performed high pressure, high temperature experiments on the refractory nitride mineral osbornite titanium nitride (TiN) to explore its stability at Earth's mantle conditions. We measured its density and crystal structure at high pressures and temperatures, finding that TiN does not change structure or melt at deep Earth conditions. Additionally, we performed Raman spectroscopy measurements to further explore the properties of TiN at high pressures. We find that TiN is a plausible mineral for nitrogen storage within the deep Earth, provided that it is chemically stable within the mantle. Key Points: We measured the thermal equation of state and vibrational properties of (titanium nitride) TiNTiN remains in the cubic rock salt structure with no melting or decomposition up to at least ∼70 GPa and ∼2,500 KFormation of TiN in the mantle may sequester N within Earth's interior, potentially solving the "missing nitrogen" problem [ABSTRACT FROM AUTHOR]

The essay discusses the works of 19th-century American author and critic William Gilmore Simms, and portrays him as an original environmentalist. Discussion focuses on Simms wariness of the effects of the industrial revolution, and the role of nature in humanity's relationship with God.

'The Mysterious Teachings of the Natural World' are given by William Gilmore Simms and Wordsworth sharing a common significant theme, that is the power of nature not only to teach and nurture the soul, but also restore it from the enervating effects of industrialism, materialism, and utilitarianism. A detailed description of their views is discussed.

The article discusses poet William Gilmore Simms' works on humor and his comic sensibility, stating that comic or light verse is often treated as a guilty pleasure.

Background: As resident attrition disrupts educational and workload balance and reduces the number of graduating physicians to care for patients, an ongoing goal of graduate medical education programs is to retain residents. Objective: We compared annual rates of resident attrition in obstetrics and gynecology (Ob-Gyn) with other clinical specialties of similar or larger size during a recent 10-year period, and explored the reasons for resident attrition. Methods: In this observational study, we analyzed annual data from the American Medical Association Graduate Medical Education Census between academic years 2000 and 2009 for residents who entered Ob-Gyn and other core clinical specialties. Our primary outcome was the trend in averaged annual attrition rates. Results: The average annual attrition was 196 ± 12 (SD) residents, representing 4.2% ± 0.5% of all Ob-Gyn residents. Rates of attrition were consistently higher among men (5.3%) and international medical school graduates (7.6%). The annual rate of attrition was similar to that for other clinical specialties (mean: 4.0%; range: from 1.5% in emergency medicine to 7.9% in psychiatry). The attrition rates for Ob-Gyn residents were relatively stable for the 10-year period (range: 3.6% in 2008 to 5.1% in 2006). Common reasons for attrition were transition to another specialty (30.0%), withdrawal/dismissal (28.2%), transfer to another Ob-Gyn program (25.4%), and leave of absence (2.2%). These proportions remained fairly constant during this 10-year period. Conclusions: The average annual attrition rate of residents in Ob-Gyn was 4.2%, comparable to most other core clinical specialties. [ABSTRACT FROM AUTHOR]

The use of prescription opioids is becoming an increasing problem among women of reproductive age. More than half of pregnancies are unintended; therefore, many first-trimester exposures to opioids occur before pregnancy confirmation. Studies are limited about the fetal risks to opioid exposure in early pregnancy. One large study demonstrated an increased risk of certain heart defects and spina bifida with first-trimester exposure to opioids. It is important to counsel women whose fetuses were exposed to opioids in early pregnancy about the potential risks, encourage them to cease using opioids or seek alternative treatments when appropriate, and use the lowest effective dose when opioid treatment is to be continued. It is also valuable to screen for anatomic abnormalities such as neural tube and cardiac defects with available maternal serum testing and ultrasound imaging in the early second trimester. Birth Defects Research (Part A) 94:620-625, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The chemical and physical properties of the interiors of terrestrial planets are largely determined during their formation and differentiation. Modeling a planet's formation provides important insights into the properties of its core and mantle, and conversely, knowledge of those properties may constrain formational narratives. Here, we present a multi-stage model of Martian core formation in which we calculate core–mantle equilibration using parameterizations from high pressure–temperature metal–silicate partitioning experiments. We account for changing core–mantle boundary (CMB) conditions, composition-dependent partitioning, and partial equilibration of metal and silicate, and we evolve oxygen fugacity (f O 2) self-consistently. The model successfully reproduces published meteorite-based estimates of most elemental abundances in the bulk silicate Mars, which can be used to estimate core formation conditions and core composition. This composition implies that the primordial material that formed Mars was significantly more oxidized (0.9–1.4 log units below the iron–wüstite buffer) than that of the Earth, and that core–mantle equilibration in Mars occurred at 42–60% of the evolving CMB pressure. On average, at least 84% of accreted metal and at least 40% of the mantle were equilibrated in each impact, a significantly higher degree of metal equilibration than previously reported for the Earth. In agreement with previous studies, the modeled Martian core is rich in sulfur (18–19 wt%), with less than one weight percent O and negligible Si. We have used these core and mantle compositions to produce physical models of the present-day Martian interior and evaluate the sensitivity of core radius to crustal thickness, mantle temperature, core composition, core temperature, and density of the core alloy. Trade-offs in how these properties affect observable physical parameters like planetary mass, radius, moment of inertia, and tidal Love number k 2 define a range of likely core radii: 1620–1870 km. Seismic velocity profiles for several combinations of model parameters have been used to predict seismic body-wave travel times and planetary normal mode frequencies. These results may be compared to forthcoming Martian seismic data to further constrain core formation conditions and geophysical properties. • Mars formed from materials with initial f O 2 between IW–0.9 and IW–1.4. • At least 84% of accreted metal equilibrated during core formation. • On average, equilibration occurred at 42–60% of the evolving CMB pressure. • The core of Mars is most likely between 1620 and 1870 km in radius. • Martian core radius may be constrained by ScS seismic travel times. [ABSTRACT FROM AUTHOR]

Tantalum pentoxide (Ta 2 O 5 ) is among the most technologically useful heavy transition metal oxides. Unfortunately, its crystal structure is the subject of long-standing and unresolved disagreement. Among other consequences, this uncertainty has made it impossible to formulate a robust high pressure equation of state for Ta 2 O 5 . Here, we report the results of high pressure x-ray diffraction experiments indexed against a comprehensive list of proposed Ta 2 O 5 phases. Five of the proposed phases produce good matches to experimental observations, and the compressibility parameters for these phases are all consistent within uncertainty. This means that regardless of the particular phase chosen, the Ta 2 O 5 equation of state can be described with bulk modulusK0=138±3.68 GPa and pressure derivativeK0'=1.82±0.45. Combining these experimental results with new density-functional theory calculations allows us to identify the λ phase as the best structural model of Ta 2 O 5 at ambient conditions., (Creative Commons Attribution license.)

A genome-wide association study (GWAS) and subsequent replication studies in diverse ethnic groups indicate that common Niemann-Pick C1 gene ( NPC1 ) polymorphisms are associated with morbid-adult obesity or diabetes independent of body weight. The objectives for this prospective cross-sectional study were to determine allele frequencies for NPC1 polymorphisms (644A>G, 1926C>G, 2572A>G, and 3797G>A) and association with metabolic disease phenotypes in an ethnically diverse New Mexican obstetric population. Allele frequencies for 1926C>G, 2572A>G, and 3797G>A were significantly different between race/ethnic groups (non-Hispanic white, Hispanic, and Native American). The results also indicated a significant pairwise linkage-disequilibrium between each of the four NPC1 polymorphisms in race/ethnic groups. Moreover, the derived and major allele for 1926C>G was associated (OR 2.11, 95% CI 1.10-3.96, P = 0.022) with increased risk for maternal prepregnancy overweight (BMI 25.0-29.9kg/m 2 ) while the ancestral and major allele for 2572A>G was associated (OR 4.68, 95% CI 1.23-17.8, P = 0.024) with increased risk for gestational diabetes in non-Hispanic whites, but not Hispanics or Native Americans. In summary, this is the first transferability study to investigate common NPC1 polymorphisms in a multiethnic population and demonstrate a differential association with increased risk for maternal prepregnancy overweight and gestational diabetes.