PECCI Code (Python Estimation for Carbon Concentration and Isotopes) for Calculating the Concentration and Stable Carbon Isotopic Composition of Dissolved Inorganic Carbon (DIC) in Precipitation for northwestern Arkansas

In karst settings, hydrograph separations using isotopic tracers are commonly and effectively used to quantify the proportions of rain rapidly delivered to springs along fractures and conduits during storm events. Dissolved inorganic carbon (DIC) is an effective, non‐conservative tracer for use in hydrograph separations of karst waters because of the ubiquitous nature of carbon in the sources of waters to caves and springs and unique concentrations and isotopic compositions of carbon inputs. DIC concentration and isotopic composition (δ¹³C‐DIC) in rain are typically calculated based on atmospheric carbon dioxide (CO₂) using equilibrium carbonate reactions and stable carbon isotope fractionation values. As atmospheric CO₂ changes, traditional assumptions applied in attaining calculated values can result in error, and better estimates of rain DIC are needed. The concentration and isotopic composition of rain DIC in the karst of northwestern Arkansas was calculated using Python™ programming language based on local atmospheric CO₂ and rain pH data from 2011 to 2013. Python™ provides an open‐source code and rapid means to complete iterative calculations, and the PECCI code (Python™ Estimation for Carbon Concentration and Isotopes) can be used for rain DIC calculations in other areas. Measured northwestern Arkansas atmospheric CO₂ had a median concentration of 397.7 ± 4.3 ppm and increased slightly over three years and median δ¹³C‐CO₂ was ‐8.5 ±0.4 ‰. Rain samples exhibited a median pH of 5.6 ±0.4. Calculated rain DIC ranged from 0.17 to 0.34 mg/L and δ13C‐DIC ranged from ‐8.5‰ to ‐8.2‰ between 5 and 30 °C. At an average annual temperature of 14.6 °C, rain DIC was calculated to be 0.25 mg/L and δ¹³C‐DIC was ‐8.34 ‰. Although the variations in DIC are small, the concentration and isotopic composition of end‐member sources in hydrograph separations controls the final hydrologic budget calculations. The PECCI code can be modified to calculate rain DIC for otherstudy sites or time periods

Lunar igneous rocks and the nature of the lunar interior

Lunar igneous rocks are interpreted, which can give useful information about mineral assemblages and mineral chemistry as a function of depth in the lunar interior. Terra rocks, though intensely brecciated, reveal, in their chemistry, evidence for a magmatic history. Partial melting of feldspathic lunar crustal material occurred in the interval 4.6 to 3.9 gy. Melting of ilmenite-bearing cumulates at depths near 100 km produced parent magmas for Apollo 11 and 17 titaniferous mare basalts in the interval 3.8 to 3.6 gy. Melting of ilmenite-free olivine pyroxenites at depths greater than 200 km produced low-titanium mare basalts in the interval 3.4 to 3.1 gy. No younger igneous rocks have yet been recognized among the lunar samples and present-day melting seems to be limited to depths greater than 1000 km

Experimental petrology and origin of Fra Mauro rocks and soil

Melting experiments over the pressure range 0 to 20 kilobars were conducted on Apollo 14 igneous rocks 14310 and 14072 and on comprehensive fines 14259. The mineralogy and textures of rocks 14310 and 14072 are presumed to be the result of near-surface crystallization. The chemical compositions of the samples show special relationships to multiply-saturated liquids in the system: anorthite-forsterite-fayalite-silica at low pressure. Partial melting of a lunar crust consisting largely of plagioclase, low calcium pyroxene, and olivine, followed by crystal fractionation at the lunar surface is proposed as a mechanism for the production of the igneous rocks and soil glasses sampled by Apollo 14

Direct microwave measurement of Andreev-bound-state dynamics in a proximitized semiconducting nanowire

The modern understanding of the Josephson effect in mesosopic devices derives from the physics of Andreev bound states, fermionic modes that are localized in a superconducting weak link. Recently, Josephson junctions constructed using semiconducting nanowires have led to the realization of superconducting qubits with gate-tunable Josephson energies. We have used a microwave circuit QED architecture to detect Andreev bound states in such a gate-tunable junction based on an aluminum-proximitized InAs nanowire. We demonstrate coherent manipulation of these bound states, and track the bound-state fermion parity in real time. Individual parity-switching events due to non-equilibrium quasiparticles are observed with a characteristic timescale $T_\mathrm{parity} = 160\pm 10~\mathrm{\mu s}$. The $T_\mathrm{parity}$ of a topological nanowire junction sets a lower bound on the bandwidth required for control of Majorana bound states

A Review of Literature on Health-Related Quality of Life of Retinoblastoma Survivors.

Background: Retinoblastoma is a malignant tumor of the eye that typically presents in early childhood and occurs in approximately 1 in 20,000 births. While active treatment of the tumor is typically completed in childhood, survivors often suffer from long-term effects from treatment including visual impairment, facial deformities, and fear of recurrence or secondary cancer. However, little is known how these long-term effects affect their health-related quality of life (HRQOL). Purpose: To review the literature on HRQOL in retinoblastoma survivors. Method: We searched three electronic databases from January 2005 to December 2018 for original research articles reporting on HRQOL or individual domains such as function, cognition, and psychosocial outcomes in retinoblastoma survivors. Results: A total of 59 articles were reviewed and 15 were identified as eligible. Five of the studies reported worse HRQOL in retinoblastoma survivors than controls or general population norms. Parent-proxy ratings were worse than survivors' self-reports. Conclusion: Our findings confirm the need for further HRQOL research to assess the factors influencing long-term outcomes associated with treatment in adolescent and young adult retinoblastoma survivors. By identifying any potential deficits in specific domains of HRQOL, early interventions might be developed to improve HRQOL in retinoblastoma survivors

Using isotopes of dissolved inorganic carbon species and water to separate sources of recharge in a cave spring, northwestern Arkansas, USA Blowing Spring Cave

Blowing Spring Cave in northwestern Arkansas is representative of cave systems in the karst of the Ozark Plateaus, and stable isotopes of water (δ18O and δ2H) and inorganic carbon (δ13C) were used to quantify soil-water, bedrock-matrix water, and precipitation contributions to cave-spring flow during storm events to understand controls on cave water quality. Water samples from recharge-zone soils and the cave were collected from March to May 2012 to implement a multicomponent hydrograph separation approach using δ18O and δ2H of water and dissolved inorganic carbon (δ13C–DIC). During baseflow, median δ2H and δ18O compositions were –41.6‰ and –6.2‰ for soil water and were –37.2‰ and –5.9‰ for cave water, respectively. Median DIC concentrations for soil and cave waters were 1.8 mg/L and 25.0 mg/L, respectively, and median δ13C–DIC compositions were –19.9‰ and –14.3‰, respectively. During a March storm event, 12.2 cm of precipitation fell over 82 h and discharge increased from 0.01 to 0.59 m3/s. The isotopic composition of precipitation varied throughout the storm event because of rainout, a change of 50‰ and 10‰ for δ2H and δ18O was observed, respectively. Although, at the spring, δ2H and δ18O only changed by approximately 3‰ and 1‰, respectively. The isotopic compositions of precipitation and pre-event (i.e., soil and bedrock matrix) water were isotopically similar and the two-component hydrograph separation was inaccurate, either overestimating (>100%) or underestimating (<0%) the precipitation contribution to the spring. During the storm event, spring DIC and δ13C–DIC decreased to a minimum of 8.6 mg/L and –16.2‰, respectively. If the contribution from precipitation was assumed to be zero, soil water was found to contribute between 23 to 72% of the total volume of discharge. Although the assumption of negligible contributions from precipitation is unrealistic, especially in karst systems where rapid flow through conduits occurs, the hydrograph separation using inorganic carbon highlights the importance of considering vadose-zone soil water when analyzing storm chemohydrographs.Keywords: carbon, stable isotopes, cave, hydrograph, Arkansas.DOI: 10.3986/ac.v42i2-3.66