A 17O Paramagnetic NMR Study of Sm2O3, Eu2O3, and Sm-/Eu- Substituted CeO2

Paramagnetic solid-state NMR of lanthanide (Ln) containing materials can be challenging due to the high electron spin states possible for the Ln f electrons, which result in large paramagnetic shifts, and these difficulties are compounded for 17O due to the low natural abundance and quadrupolar character. In this work, we present examples of 17O NMR experiments for lanthanide oxides and strategies to overcome these difficulties. In particular, we record and assign the 17O NMR spectra of monoclinic Sm2O3 and Eu2O3 for the first time, as well as performing density functional theory (DFT) calculations to gain further insight into the spectra. The temperature dependence of the Sm3+ and Eu3+ magnetic susceptibilities are investigated by measuring the 17O shift of the cubic sesquioxides over a wide temperature range, which reveal non-Curie temperature dependence due to the presence of low-lying electronic states. This behaviour is reproduced by calculating the electron spin as a function of temperature, yielding shifts which agree well with the experimental values. Using the understanding of the magnetic behaviour gained from the sesquioxides, we then explore the local oxygen environments in 15 at% Sm- and Eu-substituted CeO2, with the 17O NMR spectrum exhibiting signals due to environments with zero, one and two nearest neighbour Ln ions, as well as further splitting due to oxygen vacancies. Finally, we extract an activation energy for oxygen vacancy motion in these systems of 0.35 ± 0.02 eV from the Arrhenius temperature dependence of the 17O T1 relaxation constants, which is found to be independent of the Ln ion within error. The relation of this activation energy to literature values for oxygen diffusion in Ln-substituted CeO2 is discussed to infer mechanistic information which can be applied to further develop these materials as solid-state oxide-ion conductors.Oppenheimer Foundation. NECCES, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award No. DE-SC0012583. Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility Scientific Data and Computing Center, a component of the Computational Science Initiative, at Brookhaven National Laboratory, under Contract No. DE-SC001270

Field Theoretic Study of Bilayer Membrane Fusion III: Membranes with Leaves of Different Composition

We extend previous work on homogeneous bilayers to calculate the barriers to fusion of planar bilayers which contain two different amphiphiles, a lamellae-former and a hexagonal former, with different compositions of the twoin each leaf. Self-consistent field theory is employed, and both standard and alternative pathways are explored. We first calculate these barriers as the amount of hexagonal former is increased equally in both leaves to levels appropriate to the plasma membrane of human red blood cells. We follow these barriers as the composition of hexagonal-formers is then increased in the cis layer and decreased in the trans layer, again to an extent comparable to the biological system. We find that, while the fusion pathway exhibits two barriers in both the standard and alternative pathways, in both cases the magnitudes of these barriers are comparable to one another, and small, on the order of 13 kT. As a consequence, one expects that once the bilayers are brought sufficiently close to one another to initiate the process, fusion should occur rapidly.Comment: 9 figure

The highly variable time evolution of star-forming cores identified with dendrograms

We investigate the time evolution of dense cores identified in molecular cloud simulations using dendrograms, which are a common tool to identify hierarchical structure in simulations and observations of star formation. We develop an algorithm to link dendrogram structures through time using the three-dimensional density field from magnetohydrodynamical simulations, thus creating histories for all dense cores in the domain. We find that the population-wide distributions of core properties are relatively invariant in time, and quantities like the core mass function match with observations. Despite this consistency, an individual core may undergo large (>40%), stochastic variations due to the redefinition of the dendrogram structure between timesteps. This variation occurs independent of environment and stellar content. We identify a population of short-lived (<200 kyr) overdensities masquerading as dense cores that may comprise ~20% of any time snapshot. Finally, we note the importance of considering the full history of cores when interpreting the origin of the initial mass function; we find that, especially for systems containing multiple stars, the core mass defined by a dendrogram leaf in a snapshot is typically less than the final system stellar mass. This work reinforces that there is no time-stable density contour that defines a star-forming core. The dendrogram itself can induce significant structure variation between timesteps due to small changes in the density field. Thus, one must use caution when comparing dendrograms of regions with different ages or environment properties because differences in dendrogram structure may not come solely from the physical evolution of dense cores.Comment: 20 pages, 17 figures. Submitted to MNRA

Shotgun metagenome data of a defined mock community using Oxford Nanopore, PacBio and Illumina technologies.

Metagenomic sequence data from defined mock communities is crucial for the assessment of sequencing platform performance and downstream analyses, including assembly, binning and taxonomic assignment. We report a comparison of shotgun metagenome sequencing and assembly metrics of a defined microbial mock community using the Oxford Nanopore Technologies (ONT) MinION, PacBio and Illumina sequencing platforms. Our synthetic microbial community BMock12 consists of 12 bacterial strains with genome sizes spanning 3.2-7.2 Mbp, 40-73% GC content, and 1.5-7.3% repeats. Size selection of both PacBio and ONT sequencing libraries prior to sequencing was essential to yield comparable relative abundances of organisms among all sequencing technologies. While the Illumina-based metagenome assembly yielded good coverage with few misassemblies, contiguity was greatly improved by both, Illumina + ONT and Illumina + PacBio hybrid assemblies but increased misassemblies, most notably in genomes with high sequence similarity to each other. Our resulting datasets allow evaluation and benchmarking of bioinformatics software on Illumina, PacBio and ONT platforms in parallel

Enzyme Activity Probe and Geochemical Assessment for Potential Aerobic Cometabolism of Trichloroethene in Groundwater of the Northwest Plume, Paducah Gaseous Diffusion Plant, Kentucky

The overarching objective of the Paducah Gaseous Diffusion Plant (PGDP) enzyme activity probe (EAP) effort is to determine if aerobic cometabolism is contributing to the attenuation of trichloroethene (TCE) and other chlorinated solvents in the contaminated groundwater beneath PGDP. The site-specific objective for the EAP assessment is to identify if key metabolic pathways are present and expressed in the microbial community--namely the pathways that are responsible for degradation of methane and aromatic (e.g. toluene, benzene, phenol) substrates. The enzymes produced to degrade methane and aromatic compounds also break down TCE through a process known as cometabolism. EAPs directly measure if methane and/or aromatic enzyme production pathways are operating and, for the aromatic pathways, provide an estimate of the number of active organisms in the sampled groundwater. This study in the groundwater plumes at PGDP is a major part of a larger scientific effort being conducted by Interstate Technology and Regulatory Council (ITRC), U.S. Department of Energy (DOE) Office of Environmental Management (EM), Savannah River National Laboratory (SRNL), and North Wind Inc. in which EAPs are being applied to contaminated groundwater from diverse hydrogeologic and plume settings throughout the U.S. to help standardize their application as well as their interpretation. While EAP data provide key information to support the site specific objective for PGDP, several additional lines of evidence are being evaluated to increase confidence in the determination of the occurrence of biodegradation and the rate and sustainability of aerobic cometabolism. These complementary efforts include: (1) Examination of plume flowpaths and comparison of TCE behavior to 'conservative' tracers in the plume (e.g., {sup 99}Tc); (2) Evaluation of geochemical conditions throughout the plume; and (3) Evaluation of stable isotopes in the contaminants and their daughter products throughout the plume. If the multiple lines of evidence support the occurrence of cometabolism and the potential for the process to contribute to temporal and spatial attenuation of TCE in PGDP groundwater, then a follow-up enzyme probe microcosm study to better estimate biological degradation rate(s) is warranted

Violence Exposure and Sexual Risk Behaviors for African American Adolescent Girls: The Protective Role of Natural Mentorship and Organizational Religious Involvement

African American adolescent girls are at increased risk of being exposed to community violence and being diagnosed with a sexually transmitted infection. Fewer studies, however, have examined the protective roles of natural mentorship and organizational religious involvement as potential moderators that could lessen the effects of violence exposure on health risk behavior. Data from 273 African American ninth grade girls were used to test hypothesized independent and moderatedâ moderation models. Results suggest that natural mentorship and religious involvement were protective for girls who reported at least one mentor and moderate to high levels of religious involvement. Our findings may be relevant for community stakeholders and organizations that directly interact with religious institutions and community programs that focus on outreach to African American adolescent girls.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151908/1/ajcp12341_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151908/2/ajcp12341.pd

Self-consistent non-Markovian theory of a quantum state evolution for quantum information processing

It is shown that the operator sum representation for non-Markovian dynamics and the Lindblad master equation in Markovian limit can be derived from a formal solution to quantum Liouville equation for a qubit system in the presence of decoherence processes self-consistently. Our formulation is the first principle theory based on projection-operator formalism to obtain an exact reduced density operator in time-convolutionless form starting from the quantum Liouville equation for a noisy quantum computer. The advantage of our approach is that it is general enough to describe a realistic quantum computer in the presence of decoherence provided details of the Hamiltonians are known.Comment: 5page

Physician Empathy in Public and Private Internal Medicine Residency Training Programs in Pasig City

Research Question: What are the levels of patient-perceived and self-assessed physician empathy among internal medicine (IM) residents in two tertiary hospitals in Pasig City? Is there a significant difference in patient-perceived and self-assessed physician empathy levels between public and private tertiary hospitals? Background: Empathy is important because it has been speculated to have a positive effect on patient outcomes; it is a skill that can be learned and developed. Objectives: This study obtained quantitative measurements of patient-perceived and self-assessed physician empathy. Empathy levels between public and private tertiary hospitals were compared. General Study Design: This study utilized a quantitative cross-sectional design, with surveys as the strategy for data collection. Participants: 162 out-patient department patients aged 19-75, and 69 IM residents were sampled from one private and one public tertiary hospital. Outcome Measures: The Jefferson Scale of Patient Perceptions of Physician Empathy (JSPPPE) and the Jefferson Scale of Physician Empathy (JSE) were used to measure the empathy levels. Analysis: Sample size calculation was done using OpenEpi. An alpha level of .05 was used for computing the independent samples t-test. Results: Internal medicine patients from the private hospital rated the physicians with higher empathy scores (mean=31.23) compared to their public hospital counterparts (mean=29.01), which is significant (p=.0134). Residents from the private hospital also scored a higher self-assessed empathy score (mean=110.46) compared to physicians from the public hospital (mean=102.13), which is significant (p=.0147). Conclusion: This study provided preliminary information on the empathy levels of physicians in the Philippine setting between private and public hospitals, showing that physician empathy levels are consistently higher in the private hospital facility. The results can help hospitals incorporate or improve training in empathy in internal medicine residency programs, as empathy is known to affect patient health outcome

A randomized, phase II, three-arm study of two schedules of ixabepilone or paclitaxel plus bevacizumab as first-line therapy for metastatic breast cancer

The aim of this phase II trial was to estimate the objective response rate (ORR) of two different schedules of ixabepilone [weekly or every 3 weeks (Q3W)] combined with bevacizumab, relative to a reference arm of weekly paclitaxel and bevacizumab. Patients with human epidermal growth factor receptor 2-normal, chemotherapy-naïve metastatic breast cancer (MBC) were randomized 3:3:2 to ixabepilone 16 mg/m(2) weekly plus bevacizumab 10 mg/kg Q2W (Arm A: n = 46); ixabepilone 40 mg/m(2) Q3W (reduced to 32 mg/m(2) after four cycles of treatment) plus bevacizumab 15 mg/kg Q3W (Arm B: n = 45); or paclitaxel 90 mg/m(2) weekly plus bevacizumab 10 mg/kg intravenous infusion Q2W (Arm C: n = 32). Of 123 randomized patients, 122 were treated. All were followed for ≥19 months; 5 % of patients remained on study treatment at the time of this analysis. Grade 3 or 4 neutropenia was more common in Arm B (60 %) than Arms A (16 %) or C (22 %); other adverse events were similar. The investigator-assessed ORR was 48, 71, and 63 % for Arms A, B, and C, respectively. Median progression-free survival (randomized patients) was 9.6 months in Arm A, 11.9 months in Arm B, and 13.5 months in Arm C. In conclusion, ixabepilone Q3W plus bevacizumab has clinical activity as first-line therapy for MBC relative to paclitaxel plus bevacizumab, but with significantly greater risk of grade 3 or 4 neutropenia. In addition, these data suggest that weekly dosing of ixabepilone may be less active than Q3W dosing, but with less neutropenia

Phenotypic covariance of longevity, immunity and stress resistance in the Caenorhabditis nematodes

Background \ud Ageing, immunity and stresstolerance are inherent characteristics of all organisms. In animals, these traits are regulated, at least in part, by forkhead transcription factors in response to upstream signals from the Insulin/Insulin– like growth factor signalling (IIS) pathway. In the nematode Caenorhabditis elegans, these phenotypes are molecularly linked such that activation of the forkhead transcription factor DAF-16 both extends lifespan and simultaneously increases immunity and stress resistance. It is known that lifespan varies significantly among the Caenorhabditis species but, although DAF-16 signalling is highly conserved, it is unclear whether this phenotypic linkage occurs in other species. Here we investigate this phenotypic covariance by comparing longevity, stress resistance and immunity in four \ud Caenorhabditis species. \ud \ud Methodology/Principal Findings \ud We show using phenotypic analysis of DAF-16 influenced phenotypes that among four closely related Caenorhabditis nematodes, the gonochoristic species (Caenorhabditis remanei and Caenorhabditis brenneri) have diverged \ud significantly with a longer lifespan, improved stress resistance and higher immunity than the hermaphroditic species (C. elegans and Caenorhabditis briggsae). Interestingly, we also observe significant differences in expression levels between the daf-16 homologues in these species using Real-Time PCR, which positively correlate with the observed phenotypes. Finally, we provide additional evidence in support of a role for DAF-16 in regulating phenotypic coupling by using a combination of wildtype isolates, constitutively active daf-16 mutants and bioinformatic analysis. \ud \ud Conclusions \ud The gonochoristic species display a significantly longer lifespan (p < 0.0001)and more robust immune and stress response (p<0.0001, thermal stress; p<0.01, heavy metal stress; p<0.0001, pathogenic stress) than the hermaphroditic species. Our data suggests that divergence in DAF-16 mediated phenotypes may underlie many of the differences observed between these four species of Caenorhabditis nematodes. These findings are further supported by the correlative higher daf-16 expression levels among the gonochoristic species and significantly higher lifespan, immunity and stress tolerance in the constitutively active daf-16 hermaphroditic mutants