wR Values Research Articles

Brief High-Velocity Motor Skill Training Increases Step Frequency and Improves Length/Frequency Coordination in Slow Walkers With Chronic Motor-Incomplete Spinal Cord Injury

ObjectiveTo quantify spatiotemporal coordination during overground walking among persons with motor-incomplete spinal cord injury (PwMISCI) by calculating the step length (SL)/step frequency (SF) ratio (ie, the Walk Ratio [WR]) and to examine the effects of motor skill training (MST) on the relationship between changes in these parameters and walking speed (WS). DesignBetween-day exploratory analysis. SettingResearch laboratory in a rehabilitation hospital ParticipantsPwMISCI (N=26). Interventions3-day high-velocity MST. Main Outcome MeasuresOverground WS, SL, SF, and WR measured during the 10-Meter Walk Test. ResultsAmong the full sample, MST was associated with increases in WS, SL, SF, and a decrease in the WR. Relative change in WS and SF was higher among slow (ΔWS=↑46%, ΔSF=↑28%) vs fast (ΔWS=↑16%, ΔSF=↑8%) walkers. Change in the WR differed between groups (slow: ΔWR=↓10%; fast: ΔWR=0%). Twenty-six percent of the variability observed in ΔWR among slow walkers could be explained by ΔSF, while ΔSL did not contribute to ΔWR. Among fast walkers, ΔSL accounted for more than twice the observed ΔWR (43%) compared to ΔSF (15%). ConclusionsOn the whole, WR values among PwMISCI are higher than previous reports in other neurologic populations; however, values among fast walkers were comparable to noninjured adults. Slow walkers demonstrated greater variability in the WR, with higher values associated with slower WS. Following MST, increases in WS coincided with a decrease in the WR among slow walkers, mediated primarily through an effect on SF. This finding may point to a specific mechanism by which MST facilitates improvements in WS among PwMISCI with greater mobility deficits.

Influence of the Matrix Material and Tribological Contact Type on the Antifriction Properties of Hybrid Reinforced Polyimide-Based Nano- and Microcomposites.

This paper addresses peculiarities in the formation and adherence of a tribofilm on the wear track surface of antifriction PI- and PEI-based composites, as well as a transfer film (TF) on a steel counterface. It is shown that during hot pressing, PTFE nanoparticles melted and coalesced into micron-sized porous inclusions. In the PEI matrix, their dimensions were much larger (up to 30 µm) compared to those in the PI matrix (up to 6 µm). The phenomenon eliminated their role as effective uniformly distributed nanofillers, and the content of 5 wt.% was not always sufficient for the formation of a tribofilm or a significant decrease in the WR values. At the loaded content, the role of MoS2 and graphite (Gr) microparticles was similar, although filling with MoS2 microparticles more successfully solved the problem of adhering to a PTFE-containing tribofilm in the point tribological contact. This differed under the linear tribological contact. The higher roughness of the steel counterpart, as well as the larger area of its sliding surface with the same PTFE content in the three-component PI- and PEI-based composites, did not allow for a strong adherence of either the stable PTFE-containing tribofilm on the wear track surface or the TF on the steel counterpart. For the PEI-based composites, the inability to shield the steel counterpart from the more reactive polymer matrix, especially under the conditions of PTFE deficiency, was accompanied by multiple increases in the WR values, which were several times greater than that of neat PEI.

Preparation of a Cation Exchange Membrane by a Sol-Gel Method-Based Polyvinyl Alcohol to Improve Alkali Recovery via Diffusion Dialysis in the Textile Industry

In this work, a novel silane coupled cationic precursor (SAGS) was synthesized by 3-glycidyloxypropyltrimethoxysilane and sodium 2-((2-aminorthyl)amino) ethanesulfonate. A series of cation exchange membranes were prepared with poly(vinyl alcohol) (PVA) and SAGS by a sol-gel-based process. The structure of the prepared membranes were characterized by Fourier transform infrared spectrum (FTIR) and scanning electron microscopy (SEM), and its properties were studied by water uptake (WR), cation exchange capacity (CEC), linear expansion ratio (LER), alkali stability, thermogravimetric analysis (TGA), mechanical properties, and diffusion dialysis performance. FTIR and X-ray photoelectron spectroscopy (XPS) confirmed the successful preparation of SAGS membranes, and SEM images showed that the prepared membranes were dense and uniform. The WR values of the SAGS membranes were in the range of 91.49–122.39%, and the LER values were 17.65–28.21%. In addition, the SAGS membranes had suitable CEC value, good alkali resistance, and thermal stability which ensured the application of membranes in the field of diffusion dialysis (DD) for alkali recovery. In the DD test, the dialysis coefficients of NaOH (UOH) ranged from 0.012 mm/h to 0.023 mm/h, and the separation factors (S) was in the range of 30.77–16.43. In conclusion, the prepared CEM containing silicon oxygen bonds by PVA and SAGS reaction has the advantages of low price, friendly environment, good alkali resistance, simple preparation process, and great application potential in the textile manufacturing wastewater recovery.

Equivalent values between anterior vertebral height, wedge ratio, and wedge angle for evaluating vertebral mobility and deformity in osteoporotic vertebral fractures: a conventional observational study

BackgroundVertebral mobility (V-mobility) has been used to diagnose fresh osteoporotic vertebral fractures (OVFs) and determine bone union by setting cutoff values for these purposes. V-mobility is the difference in vertebral height on dynamic radiographs taken in the sitting and lateral decubitus or supine positions. The dimensions for V-mobility were presented as anterior vertebral height (Ha; mm), wedge ratio (WR; %), and wedge angle (WA; °) in previous reports. This study was performed to obtain WR and WA values equivalent to V-mobility of 1.0 mm in Ha.MethodsLateral radiographs of 284 OVFs (grade 1–3 deformed vertebrae) from T11 to L2 were obtained from 77 patients with OVF. V-mobility presented as Ha, posterior vertebral height, and WA was obtained by the difference in these dimensions on dynamic radiographs. The WR and WA values equivalent to 1.0 mm in Ha were obtained by dividing the V-mobility values for WR and WA by that for Ha.ResultsThe mean WR values corresponding to 1.0 mm in Ha for grade 1, 2, and 3 vertebrae were 3.2% ± 1.4%, 3.2% ± 0.9%, and 3.4% ± 1.0%, respectively, and the corresponding value for grade 1–3 vertebrae was 3.3% ± 1.0%. The mean WA values corresponding to 1.0 mm in Ha for grade 1, 2, and 3 vertebrae were 1.5° ± 0.8°, 1.5° ± 0.6°, and 1.5° ± 0.8°, respectively, and the corresponding value for grade 1–3 vertebrae was 1.5° ± 0.7°.ConclusionsThe WR and WA values equivalent to V-mobility of 1.0 mm in Ha were 3.3% and 1.5°, respectively, in grade 1–3 vertebrae. These findings may be useful to secure a reliable value of V-mobility of OVFs using simultaneous measurements in three dimensions (Ha, WR, and WA) in clinical practice and to establish cutoff values for V-mobility to determine bone union.

Tribological Behavior of Reduced Graphene Oxide-Al2O3 Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration.

The tribological properties of nanofluids are influenced by multiple factors, and the interrelationships among the factors are deserving of further attention. In this paper, response surface methodology (RSM) was used to study the tribological behavior of reduced graphene oxide–Al2O3 (rGO-Al2O3) nanofluid. The interaction effects of testing force, rotational speed and nanoparticle concentration on the friction coefficient (μ), wear rate (Wr) and surface roughness (Ra) of steel disks were investigated via the analysis of variance. It was confirmed that all the three input variables were significant for μ and Wr values, while testing force, nanoparticle concentration and its interaction with testing force and rotational speed were identified as significant parameters for Ra value. According to regression quadratic models, the optimized response values were 0.088, 2.35 × 10−7 mm3·N−1·m−1 and 0.832 μm for μ, Wr and Ra, which were in good agreement with the actual validation experiment values. The tribological results show that 0.20% was the optimum mass concentration which exhibited excellent lubrication performance. Compared to the base fluid, μ, Wr and Ra values had a reduction of approximately 45.6%, 90.3% and 56.0%. Tribochemical reactions occurred during the friction process, and a tribofilm with a thickness of approximately 20 nm was generated on the worn surface, consisting of nanoparticle fragments (rGO and Al2O3) and metal oxides (Fe2O3 and FeO) with self-lubrication properties.

Equivalent values between anterior vertebral height, wedge ratio, and wedge angle in osteoporotic vertebral fractures.

Vertebral mobility (V-mobility) has been used to diagnose fresh osteoporotic vertebral fractures (OVFs), and determine or predict bone union by setting cutoff values for these purposes. V-mobility is defined as the difference in shape of vertebral bodies between lateral radiographs taken in weight-bearing and non-weight-bearing positions. The parameters for V-mobility have varied in previous reports among anterior vertebral height (Ha, mm), wedge ratio (WR, %), and wedge angle (WA, degrees). The present study aimed to clarify WR and WA equivalent to Ha of 1.0mm, and to compare the reported cutoff values for V-mobility presented as Ha, WR, or WA. Lateral radiographs of 446 normal vertebrae (grade 0) and 146 deformed vertebrae (grade 1-3) from T11 to L2 were obtained from 183 female patients aged > 60years. WR (%) values equivalent to Ha of 1.0mm were calculated by Ha (1.0mm)/Hp × 100 (Hp: posterior vertebral height). Corresponding WA values were calculated by trigonometric function using vertebral dimensions. The mean WR values equivalent to Ha of 1.0mm in the vertebrae from T11 to L2 were 3.2%, 3.2%, 3.5%, and 3.7% for grades 0, 1, 2, and 3, respectively, and the corresponding WA values were 1.6°, 1.6°, 1.5°, and 1.4°. The equivalent values for V-mobility presented as Ha, WR, and WA were obtained. The mean WR and WA values equivalent to Ha of 1.0mm in grade 1-3 vertebrae were 3.5% and 1.5°, respectively.

Proposed Standard Weight (Ws) Equations for Arctic Grayling

AbstractRelative weight (Wr) is an index that is commonly used by fisheries managers to evaluate the condition within and among fish populations. Managers also use Wr comparisons to assess condition dynamics among species. Rather than using population‐level mean Wr for comparisons, standard length categories are frequently used to evaluate mean Wr differences among length categories. To establish Wr values for a species, a species‐specific standard weight (Ws) equation is required. Regression‐line‐percentile (RLP) and empirical‐percentile (EmP) methods were used with length–weight data that were collected from 50 Arctic Grayling Thymallus arcticus populations in the United States and Canada. The RLP method yielded a Ws equation of log10Ws(g) = −5.241 + 3.083 log10TL(mm) and the EmP method of log10Ws(g) = −5.279 + 3.096 log10TL(mm). These equations were developed to calculate relative weights (Wr) for fish measuring 150 mm total length (TL) and greater. Subsequent analysis did not reveal significant systematic length‐related bias in the application of either Ws equation. Furthermore, differences in Ws calculations between the methods were at most 2.2% over the lengths that we observed. Our findings highlight the relative importance of using a robust data set when calculating Ws equations over the method used to calculate Ws. We suggest that both equations are valid and managers should report which Ws equation was used.

Influence of the dendritic microstructure and β-Al5FeSi phase on the wear characteristics in a horizontally solidified Al-7Si-0.4Mg-1.2Fe alloy

In this work an Al-7Si-0.4Mg-1.2Fe alloy (wt.%) was subjected to a horizontal solidification experiment using a water-cooled solidification device equipped with thermocouples to obtain temperature vs. time data which in turn allowed solidification thermal parameters, such as growth and cooling rates (VL and TR, respectively), to be determined. In turn, tribological behavior of samples with different secondary dendritic spacing (λ2) and β-Al5FeSi platelets length (βFe) were assessed by means of dry sliding wear testing performed in a rotating fixed ball machine, with wear volume and rate (WV and WR, respectively) being the two main investigated wear parameters. Quantitative metallography by optical and scanning electron microscopy along with energy dispersive X-ray spectroscopy enabled both as-cast microstructures and worn craters to be characterized. More significant variations in wear resistance of the investigated alloy were found for ranges of λ2 and βFe that lie within 12−20 μm and 14–36 μm, respectively, with the coarsening of the microstructure constituted by Al-rich primary phase dendrites surrounded by α-Al + Si + θ-Mg2Si + β-Al5FeSi eutectic structures favoring reduced WV and WR values. For λ2 and βFe values higher than 24 and 48 μm, respectively, both WV and WR stabilize assuming constant values that depend on the sliding distance. In addition to power type equations relating λ2 and βFe to VL and TR, mathematical expressions for variations of WV and WR with λ2 and βFe are also proposed. Finally, a comparative analysis with the literature is presented.

Critical effects on the photosynthetic efficiency and stem sap flow of poplar in the Yellow River Delta in response to soil water

To explore the critical relationships of photosynthetic efficiency and stem sap flow to soil moisture, two-year-old poplar saplings were selected and a packaged stem sap flow gauge, based on the stem-heat balance method, and a CIRAS-2 portable photosynthesis system were used. The results show that photosynthetic rates (Pn), transpiration rates (Tr), instantaneous water use efficiency (WUE) and the stem sap flow increased initially and then decreased with decreasing soil water, but their critical values were different. The turning point of relative soil water content (Wr) from stomatal limitation to nonstomatal limitation of Pn was 42%, and the water compensation point of Pn was 13%. Water saturation points of Pn and Tr were 64% and 56%, respectively, and the WUE was 71%. With increasing soil water, the apparent quantum yield (AQY), light saturation point (LSP) and maximum net photosynthetic rate (Pnmax) increased first and then decreased, while the light compensation point (LCP) decreased first and then increased. When Wr was 64%, LCP reached a lower value of 30.7 µmol m−2 s−1, and AQY a higher value of 0.044, indicating that poplar had a strong ability to utilize weak light. When Wr was 74%, LSP reached its highest point at 1138.3 µmol∙m−2 s−1, indicating that poplar had the widest light ecological amplitude and the highest light utilization efficiency. Stem sap flow and daily sap flow reached the highest value (1679.7 g d−1) at Wr values of 56% and 64%, respectively, and then declined with increasing or decreasing Wr, indicating that soil moisture significantly affected the transpiration water-consumption of poplar. Soil water was divided into six threshold grades by critical values to maintain photosynthetic efficiency at different levels, and a Wr of 64–71% was classified to be at the level of high productivity and high efficiency. In this range, poplar had high photosynthetic capacity and efficient physiological characteristics for water consumption. The saplings had characteristics of water tolerance and were not drought resistant. Full attention should be given to the soil water environment in the Yellow River Delta when planting Populus.

Large polarization and record-high performance of energy storage induced by a phase change in organic molecular crystals.

Dielectrics that undergo electric-field-induced phase changes are promising for use as high-power electrical energy storage materials and transducers. We demonstrate the stepwise on/off switching of large polarization in a series of dielectrics by flipping their antipolar or canted electric dipoles via proton transfer and inducing simultaneous geometric changes in their π-conjugation system. Among antiferroelectric organic molecular crystals, the largest-magnitude polarization jump was obtained as 18 μC cm−2 through revisited measurements of squaric acid (SQA) crystals with improved dielectric strength. The second-best polarization jump of 15.1 μC cm−2 was achieved with a newly discovered antiferroelectric, furan-3,4-dicarboxylic acid. The field-induced dielectric phase changes show rich variations in their mechanisms. The quadruple polarization hysteresis loop observed for a 3-(4-chlorophenyl)propiolic acid crystal was caused by a two-step phase transition with moderate polarization jumps. The ferroelectric 2-phenylmalondialdehyde single crystal having canted dipoles behaved as an amphoteric dielectric, exhibiting a single or double polarization hysteresis loop depending on the direction of the external field. The magnitude of a series of observed polarizations was consistently reproduced within the simplest sublattice model by the density functional theory calculations of dipole moments flipping over a hydrogen-bonded chain or sheet (sublattice) irrespective of compounds. This finding guarantees a tool that will deepen our understanding of the microscopic phase-change mechanisms and accelerate the materials design and exploration for improving energy-storage performance. The excellent energy-storage performance of SQA was demonstrated by both a high recoverable energy-storage density Wr of 3.3 J cm−3 and a nearly ideal efficiency (90%). Because of the low crystal density, the corresponding energy density per mass (1.75 J g−1) exceeded those derived from the highest Wr values (∼8–11 J cm−3) reported for several bulk antiferroelectric ceramics , without modification to relaxor forms.

Genetics of anther culture capability traits and its association with seed yield traits in sesame

Successful development of heterotic hybrids in the autogamous sesame crop depends largely on the general combining ability of the parents as well as the specific combining ability of the hybrids produced from them. Homogeneity of Vr -Wr values and non-significance of regression coefficient (b) in a 6 parents half diallal cross were found in respect of capsule length, seeds per capsule, plant height, callus induction frequency, days to callus induction and response to somatic embryogenesis indicating validity of Hayman’s assumptions. The estimates of D, H1 and H2 components indicated predominance of non-additive gene action in the inheritance of these six traits, and the ADD estimates indicated overdominance for all these characters. The estimates of F and KD/KR indicated presence of more of dominant alleles in the parental population except for response to somatic embryogenesis. Strong positive association was recorded between seed yield and in vitro traits viz., callus induction frequency, callus fresh weight and somatic embryogenesis. This indicates that anther culture technique can assist in early screening for combining ability of parents as well as direct selection for heterotic crosses at an earlier stage of hybrid breeding programme.

Length weight relationships and condition factor of sweet river prawn, Macrobrachium esculentum (Thalwitss, 1891) in the downstream Rongkong watershed

Swett River Prawn, Macrobrachium esculentum (Thalwitz,1891) is one of the freshwater prawns’ species that have important economic value and is the least concern species in the IUCN red list. The purpose of this study was to determine the length-weight relationship and condition factor of M. esculentum in the downstream watershed Rongkong. Prawns’ sampling was conducted from September 2018 to February 2019 from the artisanal fishery in the downstream watershed Rongkong. using method simple of Random Sampling. M. ecsulentum obtained as many as 244 Prawns’ consisting of 147 male and 97 female. The results showed that the long weight relationship for males was W = 0.712L0.2865 and females W = 11.137 L3.0537. b value for males is smaller than 3, growth is allometric negative while females are positive allometric (b>3). Average condition factor values for male and female shrimp are 275.28 and 1.88, respectively. The average relative weight (Wr) values for males and females are 100.2 and 101.9, respectively, which shows that the waters are still in good condition.

Divalent Copper Selenate Complex: Two Types of Octahedral Coordination in the Unit Cell and Disordered 1,4‐Diazabicyclo[2.2.2]octane

Abstract The new hybrid compound (C6H14N2)[Cu(H2O)6][Cu(SeO4)2(H2O)4]2 crystallizes in the monoclinic system, space group P21/n, with the unit cell parameters: a = 7.2469(2) Å, b = 9.5360(2) Å, c = 22.1919(5) Å, and β = 95.789(2)°. The structure was solved by conventional direct methods. The R and wR values for 76142 measured reflections were 0.0337 and 0.0625, respectively. Within the structure of this new compound, the transition metal adopts two types of octahedral coordination. Indeed, Cu1 is coordinated by four water molecules and two selenate groups to form the tetraaquadiselenatocuprate(II) anion [Cu(SeO4)2(H2O)4]2–, whereas Cu2 adopts another octahedral environment formed by six water molecules, but three of them crystallographically independent. The Cu1 and Cu2 atoms display the so‐called (4+1+1) and (4+2) type of coordination, respectively, that has often been observed in other compounds containing the same transition metal, which is consistent with a Jahn‐Teller distortion. The crystal structure of the title complex consists of isolated metallic polyhedra and disordered dabcodiium cations linked together by two types of hydrogen bond, OW–H···O and N–H···O, only. The thermogravimetric analysis shows that the dehydration of the compound takes place in four steps. The decomposition leads to the copper oxide in the last stage.

Single crystal growth and structure refinement of hollandite-type K1.98Fe1.98Sn6.02O16

Single crystals KxFexSn8−xO16 (KFSO, x~1.98) were grown by the flux slow cooling method. Needle like single crystal having 120μm width and 3mm length at a maximum was obtained by slow cooling to 1000°C at a rate of 2°Ch−1 using starting materials with a 40mol% crystal composition of (K2O)1(Fe2O3)1(SnO2)1 and a 60% flux composition of (K2O)2(MoO3)1(B2O3)1. KFSO single crystal was refined and calculated atomic coordination, bond length and so on from the x-ray diffraction method. Final R and wR values showed 2.24% and 6.23%, respectively.

Feasibility of Pond Production of Largemouth Bass,Micropterus salmoides, for a Filet Market

AbstractThe effects of stocking density on food‐size largemouth bass (LMB),Micropterus salmoides, production (>0.5 kg) were evaluated in a 2‐yr study by stockingLMBfingerlings (mean weight = 57 g/fish) in 0.1‐ha earthen ponds at rates of 6175, 12,350, or 18,525 fish/ha. Gross yields increased from 3989 to 9096 kg/ha as stocking density increased. No significant differences were observed in survival rates (range of 65–74%) due to density. Maximum feed consumption occurred at water temperatures of 27–30 C. Feed conversion ratio (FCR) and mean harvest weight were significantly different (P < 0.05) among densities, with the lowestFCRand the lowest mean weight found at the highest density (18,525 fish/ha). At harvest,LMBwere considered to be in good condition with relative weight (Wr) values of 123–124. Dressout yield percentages were 61–62% for whole‐dressedLMBand 34–35% for shank filets.LMBgrew well and reached a size adequate for targeted shank filet sizes. However, the production costs of $7.26–$9.34/kg mean thatLMBproduction for a filet market is unlikely to be feasible. Research to lowerLMBfingerling and feed costs and improvedFCRwould contribute to improved economic feasibility.

Establishing a baseline for evaluating changes in body condition and population dynamics of sardine (Sardinops sagax) in the southern Benguela ecosystem

Standard weight (Ws) equations were developed for sardine (Sardinops sagax) in the southern Benguela ecosystem and used to provide fixed baselines for calculating relative weight (Wr) indices. The method was applied to a database of sardine length and weight measurements collected from South African coastal waters from 1953 to 2010. Statistical properties of the standard weight equations were investigated, as well as their application to sardine. Four quadratic standard-weight equations were established, using medians, means and first and third quartiles of log10-transformed weight measurements (Y) per log10-transformed caudal length class (X). A model using medians (Y=−1.825+2.679X+0.224X2) is proposed as the preferred baseline for Ws values for southern Benguela sardine, and is used to calculate Wr values over time and space. The Wr indices showed periods and areas of varied fish condition, with Wr ranging from 50 to 150 for individual fish and 97 to 106 for annual averages. The mean annual Wr index was low during the 1950s and increased to peak levels during the 1970s and 1980s, after which it showed a steady decline to 2010. There were pronounced spatial differences in sardine Wr, with both the lowest and the highest mean values seen in sardine from the upper and lower west coast, respectively, and fish from the southwest and south coast showing little difference in mean Wr. Possible causes of these temporal and spatial dynamics include environmental and ecological factors. Using sardine as an example of an exploited fish species in a changing ecosystem, we show how the Wr index could indicate the status of the population's body condition. Body condition is an important factor in fish reproduction and a proxy for habitat quality in an ecosystem. Additional information on ecosystem status could be obtained when the index is applied to other populations and species.

SU‐E‐T‐275: Voxelized Second Cancer Risk Calculation — Comparison of Proton and Photon Radiotherapies for Hodgkin Lymphoma

Purpose: The purpose of this study was to compare the risk of developing a second lung or breast cancer for a female Hodgkin Lymphoma patient treated with passively scattered proton therapy (PSPT) and photon intensity modulated radiotherapy (IMRT). Particular objectives of this work were to fully account for stray dose, perform voxel by voxel risk calculations, and to visually display risk in a manner analogous to dose visualization used in commercial treatment planning systems (CTPS). Methods: Clinically approved PSPT and IMRT treatment plans were designed using a CTPS and prescribed 36 Gy to the target volume. Neutron and stray photon dose were calculated using an in house Monte Carlo code and a TLD measurement fitted analytical model for PSPT and IMRT, respectively. For lung and breast, therapeutic and stray doses were summed and input into an in‐house program that calculates Excess Absolute Risk (EAR) per voxel in the patient based on the RadRAT risk model. The radiation weighting factor (Wr) varied for neutron doses (Wr =10 and 30) to account for biological uncertainties. Results: Neutron equivalent doses added an additional 3% (Wr =10)/9% (Wr =30) of the prescribed dose to the CTV and near field organs. Scatter dose added an additional 5% (Wr =10 )/15% (Wr =30) of the prescribed dose to organ portions far out of field. PSPT registered a lower EAR compared to IMRT except for lung when Wr =30. Larger differences were seen in low dose regions of organs. Conclusion: EAR was lower for PSPT versus IMRT unless neutron Wr values were very high, e.g.> ∼20. More work incorporating uncertainties must be done before definitive answers are determined. In the future, similar types of risk visualization tools could be incorporated into treatment plan analysis to prospectively select plans with the lowest predicted risk of second cancers. This research was supported in part, by the National Cancer Institute award 1R01CA131463‐01A1 (W.D. Newhauser, P.I.) and a subcontract of that award (R.M. Howell, P.I). No conflicts of interest to disclose.

Bis(1,10-phenanthroline-κ2N,N′)(sulfato-O)copper(II) butane-2,3-diol monosolvate

The title compound, [Cu(SO4)(C12H8N2)2]·C4H10O2, is comprised of neutral monomeric complex and butane-2,3-diol solvent mol­ecules. In the complex, the CuII ion is in a distorted square-pyramidal coordination environment defined by four N atoms from two chelating 1,10-phenanthroline ligands and one O atom from a monodentate sulfate anion; the O atom is at the apex. The two chelating N2C2 groups subtend a dihedral angle of 85.8 (4)°. In the crystal, the neutral monomeric complex and butane-2,3-diol solvent mol­ecules are held together by O—H⋯O hydrogen bonding, which leads to additional stabilization of the structure. The presence of pseudosymmetry in the structure suggests the higher symmetry space group C2/c, but attempts to refine the structure in this space group resulted in an unsatisfactory model and high R and wR values. The sulfate anion is disordered over two sets of sites with occupancies of 0.55 (1) and 0.45 (1).

Evolution of the population of very strong Mg II absorbers

Abstract We present a study of the evolution of several classes of Mg ii absorbers, and their corresponding Fe ii absorption, over a large fraction of cosmic history: 2.3–8.7 Gyr from the big bang. Our sample consists of 87 strong ( Å) Mg ii absorbers, with redshifts 0.2 < z < 2.5, measured in 81 quasar spectra obtained from the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph archives of high-resolution spectra (R ∼ 45 000). No evolutionary trend in is found for moderately strong Mg ii absorbers ( Å). However, at lower redshifts we find an absence of very strong Mg ii absorbers (those with Å) with small ratios of equivalent widths of Fe ii to Mg ii. At high redshifts, very strong Mg ii absorbers with both small and large values are present. We compare our findings to a sample of 100 weak Mg ii absorbers ( Å) found in the same quasar spectra by Narayanan et al. The main effect driving the evolution of very strong Mg ii systems is the difference between the kinematic profiles at low and high redshift. At high redshift, we observe that, among the very strong Mg ii absorbers, all of the systems with small ratios of Wr(Fe II)/Wr(Mg II) have relatively large velocity spreads, resulting in less saturated profiles. At low redshift, such kinematically spread systems are absent, and both Fe ii and Mg ii are saturated, leading to Wr(Fe II)/Wr(Mg II) values that are all close to 1. The high redshift, small Wr(Fe II)/Wr(Mg II) systems could correspond to sub-damped Lyman α systems, many of which have large velocity spreads and are possibly linked to superwinds in star-forming galaxies. In addition to the change in saturation due to kinematic evolution, the smaller Wr(Fe II)/Wr(Mg II) values could be due to a lower abundance of Fe at high redshifts, which would indicate relatively early stages of star formation in those environments.

Bis(1,10-phenanthroline-κ2N,N′)(sulfato-O)copper(II) propane-1,3-diol monosolvate

In the title compound, [Cu(SO4)(C12H8N2)2]·C3H8O2, the CuII ion is bonded to two chelating 1,10-phenanthroline (phen) ligands and one O atom from a monodentate sulfate ligand in a distorted square-based pyramidal arrangement, with the O atom in a basal site. The two chelating N2C2 groups subtend a dihedral angle of 71.10 (15)°. In the crystal, the solvent mol­ecule forms two O—H⋯O hydrogen bonds to its adjacent complex mol­ecule. The chosen crystal was found to be a racemic twin; the presence of pseudosymmetry in the structure suggests the higher symmetry space group C2/c, but attempts to refine the structure in this space group resulted in an unsatisfactory model and high R and wR values.