Palladium-bismuth intermetallic and surface-poisoned catalysts for the semi-hydrogenation of 2-methyl-3-butyn-2-ol

The effects of poisoning of Pd catalysts with Bi and annealing in a polyol (ethylene glycol) were studied on the semi-hydrogenation of 2-methyl-3-butyn-2-ol (MBY). An increase in the Pd:Bi ratio from 7 to 1 in the Bi-poisoned catalysts decreased the hydrogenation activity due to blocking of active sites, but increased maximum alkene yield from 91.5% for the Pd catalyst to 94–96% for all Bi-poisoned Pd catalysts, by decreasing the adsorption energy of alkene molecules and suppressing the formation of β-hydride phase. Annealing of the catalysts induced the formation of intermetallic phases and decreased its activity due to sintering of the catalytic particles and low activity of intermetallic compounds. Langmuir–Hinshelwood kinetic modelling of the experimental data showed that poisoning of Pd with Bi changed the relative adsorption constants of organic species suggesting ligand effects at high Bi content

Impact of education and training on type of care provided by community-based breastfeeding counselors: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Studies using community-based breastfeeding counselors (CBBCs) have repeatedly shown positive impact on breastfeeding initiation, exclusivity and duration, particularly among low-income mothers. To date, there has not been a comprehensive study to determine the impact of CBBC attributes such as educational background and training, on the type of care that CBBCs provide.</p> <p>Methods</p> <p>This was a cross-sectional study of a convenience sample of CBBCs to ascertain the influence of counselor education and type of training on type of support and proficiency of CBBCs in communities across the United States. Invitations to participate in this online survey of CBBCs were e-mailed to program coordinators of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), La Leche League, and other community-based health organizations, who in turn invited and encouraged their CBBCs to participate. Descriptive analysis was used to describe participants (N = 847), while bivariate analysis using χ²test was used to examine the differences between CBBC education, training received and breastfeeding support skills used. Multivariate logistic regression was used to assess the independent determinants of specific breastfeeding support skills.</p> <p>Results</p> <p>The major findings from the research indicate that overall, educational attainment of CBBCs is not a significant predictor for the curriculum used in their training and type of support skills used during counseling sessions, but initial training duration was positively associated with the use of many breastfeeding support skills. Another major influence of counselor support to clients is the type of continuing education they receive after their initial training, with higher likelihood of use of desirable support skills associated with counselors continuing their breastfeeding education at conferences or trainings away from their job sites.</p> <p>Conclusions</p> <p>Our results show that different programs use different training curricula to train their CBBCs varying in duration and content. Counselor education is not a significant predictor of the type of training they receive. Continuing breastfeeding education is a significant determinant of type of counseling techniques used with clients. Further research is therefore needed to critically examine the content of the various training curricula of CBBC programs. This may show a need for a standardized training curriculum for all CBBC programs worldwide to make CBBCs more proficient and efficient, ensuring successful and optimum breastfeeding experiences for mothers and their newborns.</p

Family Medicine’s Role in Addressing the Intersections of Redlining and Climate Change

Redlining, the practice of discriminating against specific neighborhoods based on race and socioeconomic status, leads to persistent environmental hazards and socioeconomic inequalities that have lasting adverse health effects on their populations. Health disparities are further exacerbated through the concentration of environmental hazards, as well as the escalating impact of climate change, which poses an increased risk of respiratory illness, cardiovascular disease, mental health issues, heat-related illness, infectious diseases, food insecurity, and socioeconomic difficulties in redline neighborhoods. This paper examines the interplay of redlining, climate change, and health disparities, with an emphasis on the enduring consequences for these marginalized communities. Through our research, we hope to foster a more equitable and just society for all by making an urgent call to action to dismantle the historical legacy of redlining and its health impacts, including climate change, for marginalized populations. Our research found that family medicine physicians, as well as other interdisciplinary collaborators and stakeholders, are pivotal to the development of comprehensive and equitable solutions for promoting health equity and resilience, as well as implementing strategies to mitigate these climate-related health issues through equitable healthcare access for all populations

Assessing the use of artificial substrates to monitor Gambierdiscus populations in the Florida Keys

© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Harmful Algae 68 (2017): 52-66, doi:10.1016/j.hal.2017.07.007.Four distinct coastal locations were sampled on a monthly basis near Long Key (Florida Keys, USA) over a 13-month period to study Gambierdiscus population dynamics on different substrates, including four macrophyte species (Dictyota spp., Halimeda spp., Laurencia spp., and Thalassia testudinum) and three artificial substrates (polyvinyl chloride (PVC) tiles, burlap, and fiberglass window screen). Cell densities of Gambierdiscus were generally lower on Dictyota versus Halimeda and Laurencia. Cell densities of Gambierdiscus were significantly correlated among macrophyte hosts in 54% of the comparisons, and between macrophyte hosts and artificial substrates in 72% of the comparisons. Predictive slopes determined from regression analyses between cell densities on artificial substrates and macrophyte hosts indicated that, on an areal basis, fewer cells were present on macrophytes versus artificial substrates (cells cm-2) and that slope variation (error) among the different macrophytes and sites ranged from 5% to 200%, averaging 61% overall. As the data required log-transformation prior to analyses, this level of error translates into two-orders of magnitude in range of estimation of the overall average abundance of Gambierdiscus cells on macrophytes (135 cells g-1 wet weight); 20 to 2690 cells g-1 ww. The lack of consistent correlation among Gambierdiscus cell densities on macrophytes versus artificial substrates, coupled with the high level of error associated with the predictive slope estimations, indicates that extreme caution should be taken when interpreting the data garnered from artificial substrate deployments, and that such deployments should be thoroughly vetted prior to routine use for monitoring purposes.Funding for this work was provided by NOAA NOS (Cooperative Agreements NA11NOS478-0060 and NA11NOS4780028)

From the track to the ocean : using flow control to improve marine bio-logging tags for cetaceans

This project was funded by the National Oceanographic Partnership Program [National Science Foundation via the Office of Naval Research N00014-11-1-0113]. C. Spencer Garborg was supported by a Grove City College Swezey Student Fellowship to Erik Anderson. Mark Johnson was funded by a Marie Curie-Sklodowska grant from the European Union. All supplemental data files are available from the Dryad Digital Repository (doi:10.5061/dryad.4j4m1).Bio-logging tags are an important tool for the study of cetaceans, but superficial tags inevitably increase hydrodynamic loading. Substantial forces can be generated by tags on fast-swimming animals, potentially affecting behavior and energetics or promoting early tag removal. Streamlined forms have been used to reduce loading, but these designs can accelerate flow over the top of the tag. This non-axisymmetric flow results in large lift forces (normal to the animal) that become the dominant force component at high speeds. In order to reduce lift and minimize total hydrodynamic loading this work presents a new tag design (Model A) that incorporates a hydrodynamic body, a channel to reduce fluid speed differences above and below the housing and wing to redirect flow to counter lift. Additionally, three derivatives of the Model A design were used to examine the contribution of individual flow control features to overall performance. Hydrodynamic loadings of four models were compared using computational fluid dynamics (CFD). The Model A design eliminated all lift force and generated up to ~30 N of downward force in simulated 6 m/s aligned flow. The simulations were validated using particle image velocimetry (PIV) to experimentally characterize the flow around the tag design. The results of these experiments confirm the trends predicted by the simulations and demonstrate the potential benefit of flow control elements for the reduction of tag induced forces on the animal.Publisher PDFPeer reviewe

Multilevel effects in the Rabi oscillations of a Josephson phase qubit

We present Rabi oscillation measurements of a Nb/AlOx/Nb dc superconducting quantum interference device (SQUID) phase qubit with a 100 um^2 area junction acquired over a range of microwave drive power and frequency detuning. Given the slightly anharmonic level structure of the device, several excited states play an important role in the qubit dynamics, particularly at high power. To investigate the effects of these levels, multiphoton Rabi oscillations were monitored by measuring the tunneling escape rate of the device to the voltage state, which is particularly sensitive to excited state population. We compare the observed oscillation frequencies with a simplified model constructed from the full phase qubit Hamiltonian and also compare time-dependent escape rate measurements with a more complete density-matrix simulation. Good quantitative agreement is found between the data and simulations, allowing us to identify a shift in resonance (analogous to the ac Stark effect), a suppression of the Rabi frequency, and leakage to the higher excited states.Comment: 14 pages, 9 figures; minor corrections, updated reference

A Survey of z>5.7 Quasars in the Sloan Digital Sky Survey II: Discovery of Three Additional Quasars at z>6

We present the discovery of three new quasars at z>6 in 1300 deg^2 of SDSS imaging data, J114816.64+525150.3 (z=6.43), J104845.05+463718.3 (z=6.23) and J163033.90+401209.6 (z=6.05). The first two objects have weak Ly alpha emission lines; their redshifts are determined from the positions of the Lyman break. They are only accurate to 0.05 and could be affected by the presence of broad absorption line systems. The last object has a Ly alpha strength more typical of lower redshift quasars. Based on a sample of six quasars at z>5.7 that cover 2870 deg^2 presented in this paper and in Paper I, we estimate the comoving density of luminous quasars at z 6 and M_{1450} < -26.8 to be (8 +/- 3)x10^{-10} Mpc^{-3} (for H_0 = 50 km/s/Mpc, Omega = 1). HST imaging of two z>5.7 quasars and high-resolution ground-based images (seeing 0.4'') of three additional z>5.7 quasars show that none of them is gravitationally lensed. The luminosity distribution of the high-redshfit quasar sample suggests the bright end slope of the quasar luminosity function at z 6 is shallower than Psi L^{-3.5} (2-sigma), consistent with the absence of strongly lensed objects.Comment: AJ in press (Apr 2003), 26 pages, 9 figure

Tocopherol Content of Maternal Breast Milk and Impact on Neonatal Growth

Background: Vitamin E is a fat-soluble nutrient consisting of α-, β-, δ-, and γ-tocopherol isoforms that has established effects on neonatal growth in utero. Higher maternal plasma tocopherol concentrations in pregnancy are associated with increased neonatal weight, length, and head circumference percentiles at birth. However, less is known about the impacts of tocopherols on post-natal growth. Since many neonates consume maternal breast milk as their post-natal nutrient source, it is important to understand the tocopherol content of breast milk and associations with neonatal growth. Significance of Problem: Although the tocopherols demonstrate positive associations with neonatal growth in utero, the role of these breast-milk-derived nutrients on post-natal growth is unclear. Enhanced understanding of these relationships can help clinicians and mothers ensure ideal nutrition and growth in their neonates. Hypothesis: We hypothesize there will be positive correlations between maternal breast milk tocopherol concentrations and post-natal growth parameters in neonates. Experimental Design: Breast milk samples were collected from postpartum mothers (N=24) whose neonates were admitted to the neonatal intensive care unit (NICU) and analyzed for α-, δ-, and γ-tocopherol concentrations using high performance liquid chromatography (HPLC). Neonatal anthropometric percentiles at 36 weeks corrected gestational age (CGA) and discharge were collected from the medical record. The Fenton growth chart was used for neonates born \u3c37 weeks CGA and the WHO growth chart for neonates born \u3e37 weeks CGA. Spearman correlations assessed the relationships between breast milk tocopherol concentrations and neonatal growth percentiles. A p-value \u3c0.05 was statistically significant. Results: 70% of neonates were born preterm (median CGA=35.9 weeks). At 36 weeks CGA, median growth percentiles were 59.9 for weight, 68.4 for length, and 60.9 for head circumference. At discharge, median growth percentiles dropped to 33.6, 41.6, and 48.3, respectively. Breast milk concentrations of α- and γ-tocopherol were significantly correlated to increased neonatal length percentile at 36 weeks CGA (both R=0.70, both p=0.016), with γ-tocopherol concentration also correlating with increased weight percentiles at 36 weeks CGA (R=0.62, p=0.033). There were no significant associations between breast milk tocopherol content and discharge growth percentiles. Conclusions: This study demonstrates the potential role of increased maternal breast milk tocopherol content on post-natal growth at 36 weeks CGA for preterm neonates. Limitations of this study include a small sample size and variability among neonates in total breast milk consumption prior to reported growth measures. Future research should assess total breast milk intake in neonates and evaluate neonatal plasma tocopherol concentrations.https://digitalcommons.unmc.edu/chri_forum/1048/thumbnail.jp

Evaluation of Tocopherol Isoforms in Maternal Breast Milk and Their Relationship with Maternal Dietary Intake

Background: Vitamin E is an essential, fat-soluble nutrient with four isoforms: α-, β-, δ-, and γ-tocopherol. These isoforms differentially modulate inflammation and show variable associations with perinatal outcomes, such as preterm delivery and Apgar scores. However, little is known about the role of these isoforms on post-natal outcomes and their presence in maternal breast milk, a neonate’s ideal nutrition source. Significance of Problem: To analyze the role of tocopherols on post-natal growth and inflammation, it is critical to first assess their presence in maternal breast milk. Relating these measures to maternal dietary intake can advance our understanding of breast milk micronutrient composition and provide an avenue for counseling lactating mothers on the importance of maternal nutrition to ensure their neonate’s health. Experimental Design: Breast milk samples were collected from postpartum mothers (N=24) whose infants were admitted to the neonatal intensive care unit (NICU) and analyzed for α-, δ-, and γ-tocopherol concentrations using high-performance liquid chromatography (HPLC). Maternal dietary intake was assessed using the Harvard Food Frequency Questionnaire. Median tocopherol concentrations and isoform proportions were generated for breast milk concentrations and intake values. Tocopherol intake adequacy was defined using the Institute of Medicine’s recommendation of 19mg of α-tocopherol daily. Mann-Whitney U-tests compared median breast milk tocopherol concentrations between intake adequate vs. deficient mothers and assessed for differences in isoform proportions between dietary intake and breast milk samples. A p-value \u3c0.05 was statistically significant. Results: 63.6% of mothers had deficient tocopherol intake (median daily intake=15.3mg α-tocopherol). Median concentrations of α-, δ-, and γ-tocopherol (ug/L) in breast milk samples were 3866.5, 768.1, and 118.6, respectively. There were no significant differences in breast milk tocopherol concentrations between intake adequate vs. deficient mothers. For both dietary intake and breast milk, α-tocopherol had the highest relative proportion (MBM=83%, intake=52%), followed by γ-tocopherol (MBM=14%, intake=39%) and δ-tocopherol (MBM=3% intake=8%). Proportions of δ- and γ-tocopherol were significantly higher in dietary intake compared to maternal breast milk (both p\u3c0.001). Conclusions: This study highlights the prevalence of overall tocopherol intake deficiency and increased proportional consumption of δ- and γ-tocopherol among lactating mothers. It also suggests a mechanism for maintaining breast milk α-tocopherol concentrations despite intake deficiency. Differences in the proportions of tocopherol isoforms between breast milk and intake measures further indicates that proportions of individual tocopherol isoforms in breast milk are influenced by factors other than dietary intake.https://digitalcommons.unmc.edu/chri_forum/1049/thumbnail.jp