Desorption of oxygen from alloyed Ag/Pt(111)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jankowski, Maciej; Wormeester, Herbert, E-mail: h.wormeester@utwente.nl; Zandvliet, Harold J. W.
2014-06-21
We have investigated the interaction of oxygen with the Ag/Pt(111) surface alloy by thermal desorption spectroscopy (TDS). The surface alloy was formed during the deposition of sub-monolayer amounts of silver on Pt(111) at 800 K and subsequent cooling to 300 K. The low-temperature phase of the surface alloy is composed of nanometer-sized silver rich stripes, embedded within platinum-rich domains, which were characterized with spot profile analysis low energy electron diffraction. The TDS measurements show that oxygen adsorption is blocked on Ag sites: the saturation coverage of oxygen decreases with increasing Ag coverage. Also, the activation energy for desorption (E{sub des})more » decreases with Ag coverage. The analysis of the desorption spectra from clean Pt(111) shows a linear decay of E{sub des} with oxygen coverage, which indicates repulsive interactions between the adsorbed oxygen atoms. In contrast, adsorption on alloyed Ag/Pt(111) leads to an attractive interaction between adsorbed oxygen atoms.« less
NASA Astrophysics Data System (ADS)
Li, Jiangtao; Hoekstra, Bart; Wang, Zhen-Bin; Qiu, Jie; Pu, Yi-Kang
2018-04-01
A relationship between the apparent secondary electron yield ({γ }{{se}}) and the oxygen coverage/oxide layer thickness on an aluminum cathode is obtained in an experiment under a controlled environment. The apparent secondary electron yield ({γ }{{se}}) is deduced from the breakdown voltage between two parallel plate electrodes in a 360 mTorr argon environment using a simple Townsend breakdown model with the assumption that the variation of the apparent secondary electron yield is dominated by the variation of the argon ion induced processes. The oxygen coverage/oxide layer thickness on the aluminum cathode is measured by a semi in situ x-ray photoemission spectroscopy equipment which is directly attached to the discharge chamber. It is found that three phases exist: (1) in the monomonolayer regime, as the oxygen coverage increases from 0 to 0.3, {γ }{{se}} decreases by nearly 40 % , (2) as the oxygen coverage increases from 0.3 to 1, {γ }{{se}} keeps nearly constant, (3) as the oxide layer thickness increases from about 0.3 nm to about 1.1 nm, {γ }{{se}} increases by 150 % . We propose that, in the submonolayer regime, the chemisorbed oxygen on the aluminum surface causes the decrease of {γ }{{se}} by creating a local potential barrier, which reduces the Auger neutralization rate and the energy gained by the Auger electrons. In the multilayer regime, as the oxide layer grows in thickness, there are three proposed mechanisms which cause the increase of {γ }{{se}}: (1) the work function decreases; (2) resonance neutralization and Auger de-excitation may exist. This is served as another channel for secondary electron production; (3) the kinetic energy of Auger electrons is increased on average, leading to a higher probability for electrons to overcome the surface potential barrier.
NASA Astrophysics Data System (ADS)
Fazleev, N. G.; Weiss, A. H.
2013-04-01
In this work we present the results of theoretical studies of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the oxidized Cu(100) surface under conditions of high oxygen coverage. An ab-initio study of the electronic properties of the Cu(100) missing row reconstructed surface at various on surface and sub-surface oxygen coverages has been performed on the basis of the density functional theory (DFT) using the Dmol3 code and the generalized gradient approximation (GGA). Surface structures in calculations have been constructed by adding oxygen atoms to various surface hollow and sub-surface octahedral sites of the 0.5 monolayer (ML) missing row reconstructed phase of the Cu(100) surface with oxygen coverages ranging from 0.5 to 1.5 ML. The charge redistribution at the surface and variations in atomic structure and chemical composition of the topmost layers associated with oxidation and surface reconstruction have been found to affect the spatial extent and localization of the positron surface state wave function and annihilation probabilities of surface trapped positrons with relevant core electrons. Theoretical results are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy (PAES). It has been shown that positron annihilation probabilities with Cu 3s and 3p core electrons decrease when total (on-surface and sub-surface) oxygen coverage of the Cu(100) surface increases up to 1 ML. The calculations show that for high oxygen coverage when total oxygen coverage is 1. 5 ML the positron is not bound to the surface.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fazleev, N. G.; Weiss, A. H.
2013-04-19
In this work we present the results of theoretical studies of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the oxidized Cu(100) surface under conditions of high oxygen coverage. An ab-initio study of the electronic properties of the Cu(100) missing row reconstructed surface at various on surface and sub-surface oxygen coverages has been performed on the basis of the density functional theory (DFT) using the Dmol3 code and the generalized gradient approximation (GGA). Surface structures in calculations have been constructed by adding oxygen atoms to various surface hollow and sub-surface octahedral sitesmore » of the 0.5 monolayer (ML) missing row reconstructed phase of the Cu(100) surface with oxygen coverages ranging from 0.5 to 1.5 ML. The charge redistribution at the surface and variations in atomic structure and chemical composition of the topmost layers associated with oxidation and surface reconstruction have been found to affect the spatial extent and localization of the positron surface state wave function and annihilation probabilities of surface trapped positrons with relevant core electrons. Theoretical results are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy (PAES). It has been shown that positron annihilation probabilities with Cu 3s and 3p core electrons decrease when total (on-surface and sub-surface) oxygen coverage of the Cu(100) surface increases up to 1 ML. The calculations show that for high oxygen coverage when total oxygen coverage is 1. 5 ML the positron is not bound to the surface.« less
NASA Astrophysics Data System (ADS)
Fazleev, N. G.; Maddox, W. B.
2010-10-01
The study of adsorption of oxygen on transition metal surface is important for the understanding of oxidation, heterogeneous catalysis, and metal corrosion. The structures formed on transition metal surfaces vary from simple adlayers of chemisorbed oxygen to oxygen diffusion into the sub-surface region and the formation of oxides. In this work we present the results of an ab-initio investigation of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the oxidized Cu(100) surface under conditions of high oxygen coverage. Calculations are performed for various high coverage missing row structures ranging between 0.50 and 1.50 ML oxygen coverage. Calculations are also performed for the on-surface adsorption of oxygen on the unreconstructed Cu(001) surface for coverages up to one monolayer to use for comparison. The geometry of the surfaces with adsorbed oxygen is fully optimized. Theoretical results are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy.
Studies of high coverage oxidation of the Cu(100) surface using low energy positrons
NASA Astrophysics Data System (ADS)
Fazleev, N. G.; Maddox, W. B.; Weiss, A. H.
2012-02-01
The study of oxidation of single crystal metal surfaces is important in understanding the corrosive and catalytic processes associated with thin film metal oxides. The structures formed on oxidized transition metal surfaces vary from simple adlayers of chemisorbed oxygen to more complex structures which result from the diffusion of oxygen into subsurface regions. In this work we present the results of theoretical studies of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the oxidized Cu(100) surface under conditions of high oxygen coverage. Calculations are performed for various high coverage missing row structures ranging between 0.50 and 1.50 ML oxygen coverage. The results of calculations of positron binding energy, positron work function, and annihilation characteristics of surface trapped positrons with relevant core electrons as function of oxygen coverage are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy (PAES).
Thermal Transport in Graphene Oxide – From Ballistic Extreme to Amorphous Limit
Mu, Xin; Wu, Xufei; Zhang, Teng; Go, David B.; Luo, Tengfei
2014-01-01
Graphene oxide is being used in energy, optical, electronic and sensor devices due to its unique properties. However, unlike its counterpart – graphene – the thermal transport properties of graphene oxide remain unknown. In this work, we use large-scale molecular dynamics simulations with reactive potentials to systematically study the role of oxygen adatoms on the thermal transport in graphene oxide. For pristine graphene, highly ballistic thermal transport is observed. As the oxygen coverage increases, the thermal conductivity is significantly reduced. An oxygen coverage of 5% can reduce the graphene thermal conductivity by ~90% and a coverage of 20% lower it to ~8.8 W/mK. This value is even lower than the calculated amorphous limit (~11.6 W/mK for graphene), which is usually regarded as the minimal possible thermal conductivity of a solid. Analyses show that the large reduction in thermal conductivity is due to the significantly enhanced phonon scattering induced by the oxygen defects which introduce dramatic structural deformations. These results provide important insight to the thermal transport physics in graphene oxide and offer valuable information for the design of graphene oxide-based materials and devices. PMID:24468660
1987-10-15
apparent shift of this band to higher energy with increasing coverage, observed at lower resolution (but higher sensitivity) in electron energy loss...apparent shift of this band to higher energy with increasing coverage, observed at lower resolution (but higher sen- sitivity) in electron energy ...11 using high-resolution electron energy -loss spectroscopy (EELS), is especially intriguing. 02 dissociates on this surface to populate two types of
NASA Astrophysics Data System (ADS)
Sexton, J. Z.; Kummel, A. C.
2004-10-01
Scanning tunneling microscopy (STM) was employed to study the mechanism for the oxidation of Al(111) with thermal O2 and NO in the 20%-40% monolayer coverage regime. Experiments show that the islands formed upon exposure to thermal O2 and NO have dramatically different shapes, which are ultimately dictated by the dynamics of the gas surface interaction. The circumference-to-area ratio and other island morphology statistics are used to quantify the average difference in the two island types. Ultrahigh-vacuum STM was employed to make the following observations: (1) Oxygen islands on the Al(111) surface, formed upon exposure to thermal oxygen, are elongated and noncompact. (2) Mixed O/N islands on the Al(111) surface, formed upon exposure to thermal nitric oxide (NO), are round and compact. (3) STM movies acquired during thermal O2 exposure indicate that a complex mechanism involving chemisorption initiated rearrangement of preexisting oxygen islands leads to the asymmetric and elongated island shapes. The overall mechanism for the oxidation of the Al(111) surface can be summarized in three regimes. Low coverage is dominated by widely isolated small oxygen features (<3 O atoms) where normal dissociative chemisorption and oxygen abstraction mechanisms are present. At 20%-40% monolayer coverage, additional oxygen chemisorption induces rearrangement of preexisting islands to form free-energy minimum island shapes. At greater than ˜40% monolayer coverage, the apparent surface oxygen coverage asymptotes corresponding to the conversion of the 2D islands to 3D Al2O3 surface crystallites. The rearrangement of oxygen islands on the surface to form the observed islands indicates that there is a short-range oxygen-oxygen attractive potential and a long-range oxygen-oxygen repulsive potential.
Ishikawa, Akio; Neurock, Matthew; Iglesia, Enrique
2007-10-31
The identity and reversibility of the elementary steps required for catalytic combustion of dimethyl ether (DME) on Pt clusters were determined by combining isotopic and kinetic analyses with density functional theory estimates of reaction energies and activation barriers to probe the lowest energy paths. Reaction rates are limited by C-H bond activation in DME molecules adsorbed on surfaces of Pt clusters containing chemisorbed oxygen atoms at near-saturation coverages. Reaction energies and activation barriers for C-H bond activation in DME to form methoxymethyl and hydroxyl surface intermediates show that this step is more favorable than the activation of C-O bonds to form two methoxides, consistent with measured rates and kinetic isotope effects. This kinetic preference is driven by the greater stability of the CH3OCH2* and OH* intermediates relative to chemisorbed methoxides. Experimental activation barriers on Pt clusters agree with density functional theory (DFT)-derived barriers on oxygen-covered Pt(111). Measured DME turnover rates increased with increasing DME pressure, but decreased as the O2 pressure increased, because vacancies (*) on Pt surfaces nearly saturated with chemisorbed oxygen are required for DME chemisorption. DFT calculations show that although these surface vacancies are required, higher oxygen coverages lead to lower C-H activation barriers, because the basicity of oxygen adatoms increases with coverage and they become more effective in hydrogen abstraction from DME. Water inhibits reaction rates via quasi-equilibrated adsorption on vacancy sites, consistent with DFT results indicating that water binds more strongly than DME on vacancies. These conclusions are consistent with the measured kinetic response of combustion rates to DME, O2, and H2O, with H/D kinetic isotope effects, and with the absence of isotopic scrambling in reactants containing isotopic mixtures of 18O2-16O2 or 12CH3O12CH3-13CH3O13CH3. Turnover rates increased with Pt cluster size, because small clusters, with more coordinatively unsaturated surface atoms, bind oxygen atoms more strongly than larger clusters and exhibit lower steady-state vacancy concentrations and a consequently smaller number of adsorbed DME intermediates involved in kinetically relevant steps. These effects of cluster size and metal-oxygen bond energies on reactivity are ubiquitous in oxidation reactions requiring vacancies on surfaces nearly saturated with intermediates derived from O2.
NASA Astrophysics Data System (ADS)
Fazleev, N. G.; Maddox, W. B.; Reed, J. A.
2011-03-01
The study of adsorption of oxygen on transition metal surface is important for the understanding of oxidation, heterogeneous catalysis, and metal corrosion. The structures formed on transition metal surfaces vary from simple adlayers of chemisorbed oxygen to more complex structures which results from diffusion of oxygen into the sub-surface regions. In this work we present the results of an ab-initio investigation of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the Cu(100) missing row reconstructed surface under conditions of high oxygen coverage. Calculations are performed for various surface and subsurface oxygen coverages ranging from 0.50 to 1.50 monolayers. Calculations are also performed for the on-surface adsorption of oxygen on the unreconstructed Cu(001) surface for coverages up to one monolayer to use for comparison. Estimates of the positron binding energy, positron work function, and annihilation characteristics reveal their sensitivity to atomic structure of the topmost layers of the surface and charge transfer. Theoretical results are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy.
Oxygen adsorption on the Al0.25Ga0.75N (0001) surface: A first-principles study
NASA Astrophysics Data System (ADS)
Fu, Jiaqi; Song, Tielei; Liang, Xixia; Zhao, Guojun
2018-04-01
To understand the interaction mechanism for the oxygen adsorption on AlGaN surface, herein, we built the possible models of oxygen adsorption on Al0.25Ga0.75N (0001) surface. For different oxygen coverage, three kinds of adsorption site are considered. Then the favorable adsorption sites are characterized by first principles calculation for (2 × 2) supercell of Al0.25Ga0.75N (0001) surface. On basis of the optimal adsorption structures, our calculated results show that all the adsorption processes are exothermic, indicating that the (0001) surface orientation is active towards the adsorption of oxygen. The doping of Al is advantage to the adsorption of O atom. Additionally, the adsorption energy decreases with reducing the oxygen coverage, and the relationship between them is approximately linear. Owing to the oxygen adsorption, the surface states in the fundamental band gap are significant reduced with respect to the free Al0.25Ga0.75N (0001) surface. Moreover, the optical properties on different oxygen coverage are also discussed.
Influence of preadsorbed oxygen on activated chemisorption of methane on Pd(110)
NASA Astrophysics Data System (ADS)
Valden, M.; Pere, J.; Xiang, N.; Pessa, M.
1996-07-01
Dissociative chemisorption of methane on clean and oxygen modified Pd(110) has been studied by using molecular beam surface scattering. The absolute dissociation probability of CH 4 ( Stot) is found to increase exponentially with the incident normal energy ( En) of CH 4 and with surface temperature ( TS) on clean Pd(110). The kinetic isotope effect is also found; namely, Stot of CD 4 is 4 to 5 times smaller than Stot of CH 4 throughout the entire range of En studied. These results are consistent with a direct dissociation mechanism. Measurements on preadsorbed oxygen on Pd(110) show that Stot of CH 4 decreases linearly, as oxygen coverage is increased from 0 to 0.4 ML in good agreement with the first-order Langmuir kinetics when approximately two active sites are blocked by one oxygen atom. No influence of the oxygen induced surface reconstructions on the dissociative adsorption kinetics of CH 4 is observed.
NASA Astrophysics Data System (ADS)
Ismail, Ahmed E.; Grest, Gary S.; Stevens, Mark J.
2007-03-01
Oligo(ethylene oxide) self-assembled monolayers (OEO SAM's) deposited on Au are the prototypical materials used to study protein resistance. Recently, protein resistance has been shown to vary as a function of surface coverage and to be maximal at about two-thirds coverage, not complete coverage. We use molecular dynamics simulations to study the nature of the interface between water and the OEO SAM for a range of SAM coverages. As SAM coverage decreases, the amount of water within the OEO monolayer increases monotonically; however, the penetration depth of the water shows a maximum near the experimentally-found maximal coverage. As the water content increases, the SAM-water mixture becomes harder to distinguish from bulk water. Since the oxygen atoms of OEO are hydrogen bond acceptors, a hydrogen bond network forms within the SAM-water mixture. The water molecules diffuse freely within the monolayer and exchange with the bulk water. Because the monolayer becomes increasingly like bulk water as the coverage decreases, proteins stay in their bulk soluble conformation and do not adsorb. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract No. DE-AC04-94AL85000.
NASA Astrophysics Data System (ADS)
Jones, G. Scott; Barteau, Mark A.; Vohs, John M.
1999-01-01
The reactions of iodoethane (ICH 2CH 3) on clean and oxygen-covered Ag(110) surfaces were investigated using temperature-programmed desorption (TPD) and high-resolution electron energy-loss spectroscopy (HREELS). Iodoethane adsorbs dissociatively at 150 K to produce surface ethyl groups on both clean and oxygen-covered Ag(110) surfaces. The ethyl species couple to form butane on both surfaces, with the desorption peak maximum located between 218 and 238 K, depending on the ethyl coverage. In addition to butane, a number of oxidation products including diethyl ether, ethanol, acetaldehyde, surface acetate, ethylene, carbon dioxide and water were formed on the oxygen-dosed Ag(110) surface. Diethyl ether was the major oxygenate produced at all ethyl:oxygen ratios, and the peak temperature for ether evolution varied from 220 to 266 K depending on the relative coverages of these reactants. The total combustion products, CO 2 and H 2O, were primarily formed at low ethyl coverages in the presence of excess oxygen. The formation of ethylene near 240 K probably involves an oxygen-assisted dehydrogenation pathway since ethylene is not formed from ethyl groups on the clean surface. Acetaldehyde and ethanol evolve coincidentally with a peak centered at 270-280 K, and are attributed to the reactions of surface ethoxide species. The surface acetate which decomposes near 620 K is formed from subsequent reactions of acetaldehyde with oxygen atoms. The addition of ethyl to oxygen to form surface ethoxides was verified by HREELS results. The yields of all products exhibited a strong dependence on the relative coverages of ethyl and oxygen.
NASA Astrophysics Data System (ADS)
Xu, Ya; Sakurai, Junya; Teraoka, Yuden; Yoshigoe, Akitaka; Demura, Masahiko; Hirano, Toshiyuki
2017-01-01
The initial oxidation behavior of a clean Ni3Al (210) surface was studied at 300 K using a supersonic O2 molecular beam (O2 SSMB) having an O2 translational energy of 2.3 eV, and real-time photoemission spectroscopy performed with high-brilliance synchrotron radiation. The evolution behaviors of the O 1s, Ni 2p, Al 2p, and Ni 3p spectra were examined during irradiation with the O2 SSMB. The spectral analysis revealed that both the Al atoms and the Ni atoms on the surface were oxidized; however, the oxidation of Al progressed much faster than that of Ni. The oxidation of Al began to occur and AlOx was formed at an oxygen coverage of 0.26 monolayer (ML) (1 ML was defined as the atomic density of the Ni3Al (210) surface) and saturated at an oxygen coverage of 2.5 ML. In contrast, the oxidation of Ni commenced a little late at an oxygen coverage of 1.6 ML and slowly progressed to saturation, which occurred at an oxygen coverage of 4.89 ML.
NASA Astrophysics Data System (ADS)
Yuan, Shuai; Qiu, Zhiwen; Zhang, Hailiang; Gong, Haibo; Hao, Yufeng; Cao, Bingqiang
2016-01-01
During the growth of CH3NH3PbI3-xClx (MAPbI3-xClx) perovskite films by the two-step inter-diffusion method, the presence of a trace amount of oxygen gas is critical to their physical properties and photovoltaic performance. As the oxygen concentration increases, poor film morphologies and incomplete surface coverage are observed. Moreover, by XRD, Raman scattering, and photoluminescence measurements, we find that MAPbI3-xClx grains become more distorted and the electron-hole recombination rate dramatically increases. Higher oxygen concentration triggers a sharp decrease in the current density and the fill factor of corresponding solar cells, which degrades device performance, on average, from 14.3% to 4.4%. This work proves the importance of controlling the oxygen atmosphere in the fabrication of high-performance perovskite solar cells.
Sanghavi, Shail; Wang, Weina; Nandasiri, Manjula I.; ...
2016-05-12
We studied the interactions between the carboxylate anchoring group from trimethylacetic acid (TMAA) and CeO 2(111) surfaces as a function of oxygen stoichiometry using in situ X-ray photoelectron spectroscopy (XPS). The stoichiometric CeO 2(111) surface was obtained by annealing the thin film under 2.0 × 10 –5 Torr of oxygen at ~550 °C for 30 min. In order to reduce the CeO 2(111) surface, the thin film was annealed under ~5.0 × 10 –10 Torr vacuum conditions at 550 °C, 650 °C, 750 °C and 850 °C for 30 min to progressively increase the oxygen defect concentration on the surface.more » The saturated TMAA coverage on the CeO 2(111) surface determined from XPS elemental composition is found to increase with increasing oxygen defect concentration. This is attributed to the increase of under-coordinated cerium sites on the surface with the increase in the oxygen defect concentrations. Furthermore, XPS results were in agreement with periodic density functional theory (DFT) calculations and indicate a stronger binding between the carboxylate group from TMAA and the oxygen deficient CeO 2–δ(111) surface through dissociative adsorption.« less
Activated adsorption of methane on clean and oxygen-modified Pt?111? and Pd?110?
NASA Astrophysics Data System (ADS)
Valden, M.; Pere, J.; Hirsimäki, M.; Suhonen, S.; Pessa, M.
1997-04-01
Activated adsorption of CH 4 on clean and oxygen modified Pt{111} and Pd{110} has been studied using molecular beam surface scattering. The absolute dissociation probability of CH 4 was measured as a function of the incident normal energy ( E) and the surface temperature ( Ts). The results from clean Pt{111} and Pd{110} are consistent with a direct dissociation mechanism. The dissociative chemisorption dynamics of CH 4 is addressed by using quantum mechanical and statistical models. The influence of adsorbed oxygen on the dissociative adsorption of CH 4 on both Pt{111} and Pd{110} shows that the dissociation probability decreases linearly with increasing oxygen coverage.
Coverage-dependent adsorption and desorption of oxygen on Pd(100)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dunnen, Angela den; Jacobse, Leon; Wiegman, Sandra
2016-06-28
We have studied the adsorption and desorption of O{sub 2} on Pd(100) by supersonic molecular beam techniques and thermal desorption spectroscopy. Adsorption measurements on the bare surface confirm that O{sub 2} initially dissociates for all kinetic energies between 56 and 380 meV and surface temperatures between 100 and 600 K via a direct mechanism. At and below 150 K, continued adsorption leads to a combined O/O{sub 2} overlayer. Dissociation of molecularly bound O{sub 2} during a subsequent temperature ramp leads to unexpected high atomic oxygen coverages, which are also obtained at high incident energy and high surface temperature. At intermediatemore » temperatures and energies, these high final coverages are not obtained. Our results show that kinetic energy of the gas phase reactant and reaction energy dissipated during O{sub 2} dissociation on the cold surface both enable activated nucleation of high-coverage surface structures. We suggest that excitation of local substrate phonons may play a crucial role in oxygen dissociation at any coverage.« less
NASA Astrophysics Data System (ADS)
Wei, Shiqian; Wang, Fang; Dan, Meng; Zeng, Kaiyue; Zhou, Ying
2017-11-01
In this work, spin-polarized DFT + U method has been employed to investigate adsorption properties of H2S on the rutile TiO2 (110) surface with a high coverage of bridging oxygen vacancies (BOVs). The influence of different BOV coverage (θ-BOVs) on the surface electronic structure is examined. Defected states increase within the band gap with θ-BOVs increasing from 1/8 to 4/8 monolayer (ML). The high defected surface with θ-BOVs = 4/8 ML is determined to have a desired band structure and noticeable visible light response. In addition, H2S adsorption behaviors are noticeably affected by different H2S coverage (θ-H2S). Particularly, it is found molecular adsorption at θ-H2S ≤ 1/8 ML and dissociative adsorption at the higher θ-H2S. The maximization of spontaneous dissociation of H2S can be realized when the BOVs are all covered by H2S molecules. This work gains mechanistic insights into BOVs in tuning the surface properties and provides a guide for the effective utilization of the active surface sites on the rutile TiO2 (110) in the field of H2S splitting.
Surface Coverage and Metallicity of ZnO Surfaces from First-Principles Calculations
NASA Astrophysics Data System (ADS)
Zhang, Xiao; Schleife, Andre; The Schleife research Group Team
Zinc oxide (ZnO) surfaces are widely used in different applications such as catalysis, biosensing, and solar cells. These surfaces are, in many cases, chemically terminated by hydroxyl groups. In experiment, a transition of the ZnO surface electronic properties from semiconducting to metallic was reported upon increasing the hydroxyl coverage to more than approximately 80 %. The reason for this transition is not well understood yet. We report on first-principles calculations based on density functional theory for the ZnO [ 10 1 0 ] surface, taking different amounts of hydroxyl coverage into account. We calculated band structures for fully relaxed configurations and verified the existence of this transition. However, we only find the fully covered surface to be metallic. We thus explore the possibility for clustering of the surface-terminating hydroxyl groups based on total-energy calculations. We also found that the valence band maximum consists of oxygen p states from both the surface hydroxyl groups and the surface oxygen atoms of the material. The main contribution to the metallicity is found to be from the hydroxyl groups.
Adsorption isotherms of water on mica: redistribution and film growth.
Malani, Ateeque; Ayappa, K G
2009-01-29
Adsorption isotherms of water on muscovite mica are obtained using grand canonical Monte Carlo simulations over a wide range of relative vapor pressures, p/p(0) at 298 K. Three distinct stages are observed in the adsorption isotherm. A sharp rise in the water coverage occurs for 0 < p/p(0) < 0.1. This is followed by a relatively slow increase in the coverage for 0.1 < or = p/p(0) < or = 0.7. Above p/p(0) = 0.7, a second increase in the coverage occurs due to the adsorption of water with bulklike features. The derived film thickness and isotherm shape for the simple point charge (SPC) water model is in excellent agreement with recent experiments of Balmer et al. [ Langmuir 2008 , 24 , 1566 ]. A novel observation is the significant redistribution of water between adsorbed layers as the water film develops. This redistribution is most pronounced for 0.1 < or = p/p(0) < or = 0.7, where water is depleted from the inner layers and film growth is initiated on the outer layer. During this stage, potassium hydration is found to play a dominant role in the rearrangement of water near the mica surface. The analysis of structural features reveals a strongly bound first layer of water molecules occupying the ditrigonal cavities between the potassium ions. In-plane structure of oxygen in the second layer, which forms part of the first hydration shell of potassium, reveals a liquidlike structure with the oxygen-oxygen pair correlation function displaying features similar to bulk water. Isosteric heats of adsorption were found to be in good agreement with the differential microcalorimetric data of Rakhmatkariev ( Clays Clay Miner. 2006 , 54 , 402 ), over the entire range of pressures investigated. Both SPC and extended simple point charge (SPC/E) water models were found to yield qualitatively similar adsorption and structural characteristics, with the SPC/E model predicting lower coverages than the SPC model for p/p(0) > 0.7.
Johnston, Christina M; Strbac, Svetlana; Lewera, Adam; Sibert, Eric; Wieckowski, Andrzej
2006-09-12
Catalytic activity of the Pt(111)/Os surface toward methanol electrooxidation was optimized by exploring a wide range of Os coverage. Various methods of surface analyses were used, including electroanalytical, STM, and XPS methods. The Pt(111) surface was decorated with nanosized Os islands by spontaneous deposition, and the Os coverage was controlled by changing the exposure time to the Os-containing electrolyte. The structure of Os deposits on Pt(111) was characterized and quantified by in situ STM and stripping voltammetry. We found that the optimal Os surface coverage of Pt(111) for methanol electrooxidation was 0.7 +/- 0.1 ML, close to 1.0 +/- 0.1 Os packing density. Apparently, the high osmium coverage Pt(111)/Os surface provides more of the necessary oxygen-containing species (e.g., Os-OH) for effective methanol electrooxidation than the Pt(111)/Os surfaces with lower Os coverage (vs e.g., Ru-OH). Supporting evidence for this conjecture comes from the CO electrooxidation data, which show that the onset potential for CO stripping is lowered from 0.53 to 0.45 V when the Os coverage is increased from 0.2 to 0.7 ML. However, the activity of Pt(111)/Os for methanol electrooxidation decreases when the Os coverage is higher than 0.7 +/- 0.1 ML, indicating that Pt sites uncovered by Os are necessary for sustaining significant methanol oxidation rates. Furthermore, osmium is inactive for methanol electrooxidation when the platinum substrate is absent: Os deposits on Au(111), a bulk Os ingot, and thick films of electrodeposited Os on Pt(111), all compare poorly to Pt(111)/Os. We conclude that a bifunctional mechanism applies to the methanol electrooxidation similarly to Pt(111)/Ru, although with fewer available Pt sites. Finally, the potential window for methanol electrooxidation on Pt(111)/Os was observed to shift positively versus Pt(111)/Ru. Because of the difference in the Os and Ru oxophilicity under electrochemical conditions, the Os deposit provides fewer oxygen-containing species, at least below 0.5 V vs RHE. Both higher coverage of Os than Ru and the higher potentials are required to provide a sufficient number of active oxygen-containing species for the effective removal of the site-blocking CO from the catalyst surface when the methanol electrooxidation process occurs.
NASA Astrophysics Data System (ADS)
Valentini, Paolo; Schwartzentruber, Thomas E.; Cozmuta, Ioana
2011-12-01
Atomic-level Grand Canonical Monte Carlo (GCMC) simulations equipped with a reactive force field (ReaxFF) are used to study atomic oxygen adsorption on a Pt(111) surface. The off-lattice GCMC calculations presented here rely solely on the interatomic potential and do not necessitate the pre-computation of surface adlayer structures and their interpolation. As such, they provide a predictive description of adsorbate phases. In this study, validation is obtained with experimental evidence (steric heats of adsorption and isotherms) as well as DFT-based state diagrams available in the literature. The ReaxFF computed steric heats of adsorption agree well with experimental data, and this study clearly shows that indirect dissociative adsorption of O2 on Pt(111) is an activated process at non-zero coverages, with an activation energy that monotonically increases with coverage. At a coverage of 0.25 ML, a highly ordered p(2 × 2) adlayer is found, in agreement with several low-energy electron diffraction observations. Isotherms obtained from the GCMC simulations compare qualitatively and quantitatively well with previous DFT-based state diagrams, but are in disagreement with the experimental data sets available. ReaxFF GCMC simulations at very high coverages show that O atoms prefer to bind in fcc hollow sites, at least up to 0.8 ML considered in the present work. At moderate coverages, little to no disorder appears in the Pt lattice. At high coverages, some Pt atoms markedly protrude out of the surface plane. This observation is in qualitative agreement with recent STM images of an oxygen covered Pt surface. The use of the GCMC technique based on a transferable potential is particularly valuable to produce more realistic systems (adsorbent and adsorbate) to be used in subsequent dynamical simulations (Molecular Dynamics) to address recombination reactions (via either Eley-Rideal or Langmuir-Hinshelwood mechanisms) on variously covered surfaces. By using GCMC and Molecular Dynamics simulations, the ReaxFF force field can be a valuable tool for understanding heterogeneous catalysis on a solid surface. Finally, the use of a reactive potential is a necessary requirement to investigate problems where dissociative adsorption occurs, as typical of many important catalytic processes.
Oxygen chemisorption on copper (110)
NASA Astrophysics Data System (ADS)
Mundenar, J. M.; Baddorf, A. P.; Plummer, E. W.; Sneddon, L. G.; Didio, R. A.; Zehner, D. M.
1987-09-01
High resolution electron energy loss spectroscopy (EELS) and angle-resolved ultra-violet photoelectron spectroscopy (UPS) have been used: (1) to study a surface phonon of Cu(110) as a function of oxygen coverage, (2) to identify oxygen adsorption site(s) in the p(2×1)O, c(6×2)O, and disordered oxygen overlayer (formed by O 2 exposure at 100 K), and (3) to determine whether molecular adsorption or dissociation of O 2 followed by atomic adsorption occurs after oxygen exposure at 100 K. With EELS, a continuous shift in energy of the surface phonon as a function of oxygen exposure at 300 K is observed. Our EELS data for the p(2×1)O overlayer support previous reports of a single long-bridge adsorption site, while indicating two sites are populated in the c(6×2)O overlayer: a long-bridge site and a four-coordinated site. The long-bridge site is populated at all coverages while the four-coordinated sites is occupied only after high exposures (≥2×10 4 L) at room temperature, or after exposures >2 L at low temperature (100 K). For both conditions the oxygen coverages are greater than 0.5 monolayer. Also, EELS and complementary UPS data clearly show that oxygen adsorbs dissociatively on Cu(110) after O 2 exposure at 100 K. At this temperature, LEED results indicate that the oxygen atoms are adsorbed without long-range order; however, local adsorption sites, which are similar to those in the c(6×2)O surface, are observed.
Characteristics of Honeycomb-Type Oxygen Generator with Electrolyte Based on Doped Bismuth Oxide
NASA Astrophysics Data System (ADS)
Chen, Yu-Wen; Liu, Yi-Xin; Wang, Sea-Fue; Devasenathipathy, Rajkumar
2018-03-01
An oxygen generator using Y-doped Bi2O3 as electrolyte to transport oxygen ions has been developed, having honeycomb-type structure with dimensions of 40 mm × 35 mm × 30 mm and consisting of 13 × 12 channels. External wire circuitry for the channels arrayed using parallel, series, and hybrid connection was evaluated to achieve the best oxygen separation efficiency. It was observed that the oxygen generator with hybrid connection facilitated evolution of oxygen at maximum of 117 sccm and high purity > 99.9% at 550°C under current flow of 14 A. Addition of 5 wt.% silane and 3 wt.% glass-ceramic powder to the Ag slurry used at both electrodes not only increased the coverage of the metal electrode on the ceramic substrate during dip coating but also prevented cracking at the electrode layer of the module under stress from the electric field and temperature during high-temperature operation, thus reducing the decay rate of the oxygen generator in durability testing.
Secondary ion generation mechanism studied by ISS-SIMS and work function measurements
NASA Astrophysics Data System (ADS)
Kawatoh, Eizoh; Terada, Norihito; Shimizu, Ryuichi; Kang, Hee Jae
1989-03-01
Oxygen enhancement effects in secondary ion generation were studied in polycrystalline Ni at different partial pressures of oxygen, Po2, by sequential ISS-SIMS and work function measurements. The investigation has revealed that the enhancement undergoes three stages: (I) The secondary ion intensity increases monotonically with an increase of work function which is described very well by the electron tunneling model. (II) This tendency abruptly changes, i.e. the work function decreases and the secondary ion intensity increases rapidly, for a slight increase of Po2 (III) The secondary ion intensities gradually increase and become saturated with a further increase of Po2. It has also been found that the critical coverage, θc, corresponds exactly to the stage (II) behaviour, which was observed by Blaise and Bernheim for a single crystal (100)Ni surface.
NASA Technical Reports Server (NTRS)
Shanabarger, M. R.
1986-01-01
Measurements have been made of the chemisorption-induced resistance change for H2 adsorbed onto Fe film substrates predosed with fixed coverages of chemisorbed oxygen. The measurements were made at temperatures from 295 to 340 K and for estimated oxygen coverages of less than 0.1 monolayers. Two distinct resistance change components were observed in both the adsorption kinetics and the equilibrium isotherms: a positive component which is associated with the adsorption of H2 onto a clean Fe surface, and a negative component which was correlated with the presence of the chemisorbed oxygen. The resistance change isotherms can be fit with a model which assumes that each of the resistance change components result from dissociative chemisorbed hydrogen. Possible mechanisms for the chemisorbed-oxygen-induced negative resistance change are discussed.
Boosting water oxidation layer-by-layer.
Hidalgo-Acosta, Jonnathan C; Scanlon, Micheál D; Méndez, Manuel A; Amstutz, Véronique; Vrubel, Heron; Opallo, Marcin; Girault, Hubert H
2016-04-07
Electrocatalysis of water oxidation was achieved using fluorinated tin oxide (FTO) electrodes modified with layer-by-layer deposited films consisting of bilayers of negatively charged citrate-stabilized IrO2 NPs and positively charged poly(diallyldimethylammonium chloride) (PDDA) polymer. The IrO2 NP surface coverage can be fine-tuned by controlling the number of bilayers. The IrO2 NP films were amorphous, with the NPs therein being well-dispersed and retaining their as-synthesized shape and sizes. UV/vis spectroscopic and spectro-electrochemical studies confirmed that the total surface coverage and electrochemically addressable surface coverage of IrO2 NPs increased linearly with the number of bilayers up to 10 bilayers. The voltammetry of the modified electrode was that of hydrous iridium oxide films (HIROFs) with an observed super-Nernstian pH response of the Ir(III)/Ir(IV) and Ir(IV)-Ir(IV)/Ir(IV)-Ir(V) redox transitions and Nernstian shift of the oxygen evolution onset potential. The overpotential of the oxygen evolution reaction (OER) was essentially pH independent, varying only from 0.22 V to 0.28 V (at a current density of 0.1 mA cm(-2)), moving from acidic to alkaline conditions. Bulk electrolysis experiments revealed that the IrO2/PDDA films were stable and adherent under acidic and neutral conditions but degraded in alkaline solutions. Oxygen was evolved with Faradaic efficiencies approaching 100% under acidic (pH 1) and neutral (pH 7) conditions, and 88% in alkaline solutions (pH 13). This layer-by-layer approach forms the basis of future large-scale OER electrode development using ink-jet printing technology.
Mechanical properties of graphene oxides.
Liu, Lizhao; Zhang, Junfeng; Zhao, Jijun; Liu, Feng
2012-09-28
The mechanical properties, including the Young's modulus and intrinsic strength, of graphene oxides are investigated by first-principles computations. Structural models of both ordered and amorphous graphene oxides are considered and compared. For the ordered graphene oxides, the Young's modulus is found to vary from 380 to 470 GPa as the coverage of oxygen groups changes, respectively. The corresponding variations in the Young's modulus of the amorphous graphene oxides with comparable coverage are smaller at 290-430 GPa. Similarly, the ordered graphene oxides also possess higher intrinsic strength compared with the amorphous ones. As coverage increases, both the Young's modulus and intrinsic strength decrease monotonically due to the breaking of the sp(2) carbon network and lowering of the energetic stability for the ordered and amorphous graphene oxides. In addition, the band gap of the graphene oxide becomes narrower under uniaxial tensile strain, providing an efficient way to tune the electronic properties of graphene oxide-based materials.
NASA Astrophysics Data System (ADS)
Lousada, Cláudio M.; Korzhavyi, Pavel A.
2018-05-01
The formation of islands of O-atoms is the dominant mode of growth of the oxide in the first stages of oxidation of Al(1 1 1). It is however unknown if a similar mechanism exists for other low index surfaces of Al. We performed a density functional theory (DFT) and ab initio molecular dynamics investigation of the first stages of the oxidation of Al(1 1 0) using two distinct models: a homogeneous surface disposition of O-atoms; and a model where the O-atoms are close-spaced forming clusters or islands. We investigated the surface reactions with oxygen up to a coverage of 2 ML and found that for both models the adsorption energy per dissociating O2(g) becomes more negative with increasing coverage. Our results show that for coverages up to 1.25 ML the oxide forms clusters or islands while for coverages higher than 1.5 ML the oxide covers the surface homogeneously. This is because the O-atoms bind preferably to neighboring sites even at the minimum coverage. With increasing coverage, the clusters of O start to form stripes along the [1 1 bar 0] direction. The work function (ϕ) of the surface decreases when going from bare Al(1 1 0) to up to 1 ML coverage of O-atoms, but for coverages of 1.25 ML and higher, ϕ increases. The Al 2p surface core level shifts (SCLS) shift towards higher binding energies with increasing surface coverage of O-atoms and start to approach the values of Al 2p in Al2O3 already at a coverage of 2ML. A relation between the SCLS and the coordination number of Al to O-atoms was made. The Al 2p SCLS increases with increasing coordination to O-atoms, for single, twofold and three-fourfold coordinated cations. For the O-atoms that terminate the surface at the short-bridge sites, the SCLS of O 1s, is largely affected by the proximity to other O-atoms. These results demonstrate that the cooperative effects between surface bound O-atoms have important roles in the mechanism of growth of the oxide at Al(1 1 0), and similarly to what happens for Al(1 1 1), the initial oxidation of Al(1 1 0) proceeds via the formation of islands of O-atoms.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Petrik, Nikolay G.; Henderson, Michael A.; Kimmel, Gregory A.
Angle-resolved photon stimulated desorption (PSD) combined with infrared reflection-adsorption spectroscopy and temperature programmed desorption reveal two distinct channels in the photochemistry of acetone on rutile TiO₂(110) surface. During UV irradiation of co-adsorbed oxygen and acetone molecules, methyl radicals (CH₃) are ejected in two different directions: i) normal to the surface and ii) off-normal at ~±66° to the surface normal in the azimuth (i.e. perpendicular to the rows of bridging oxygen and Ti atoms). Both components are relatively narrow and non-cosine, indicating non-thermal evolution of CH₃ radicals. The direction of the “off-normal” PSD component is consistent with orientation of the C–CH₃more » bonds in the n²-acetone diolate—a photoactive form of acetone chemisorption on the oxidized TiO₂(110) surface proposed earlier from experimental and theoretical studies. The direction of the “normal” PSD component requires an orientation of a C–CH₃ bond which is not consistent with the n²-acetone diolate structure. The angular distribution of the CH₃ PSD depends on the acetone coverage. The “off-normal” PSD component dominates at lower acetone coverage (< 0.2 ML), but does not increase at higher coverages in accord with the acetone diolate peak intensity in the infrared reflection-absorption spectra. The “normal” PSD component grows with the acetone coverage up to 0.6 ML. The newly discovered “normal” PSD channel is tentatively assigned to a photo-produced n²- acetone enolate as a potential precursor based on the H/D exchange experiments« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shao, Dahai
2013-05-15
This dissertation focuses on how QSE-stabilized, surface-supported Ag nanoclusters will interact with ethylene or oxygen. Experiments are performed to determine whether the QSE-mediated Ag islands react differently toward adsorption of ethylene or oxygen, or whether the adsorption of these small molecules will affect the QSE-mediated stability of Ag islands. Studies of the interaction of oxygen with Ag/Si(111)-7×7 were previously reported, but these studies were performed at a low Ag coverage where 3D Ag islands were not formed. So the study of such a system at a higher Ag coverage will be a subject of this work. The interaction of ethylenemore » with Ag/Si(111)-7×7, as well as the interaction of oxygen with Ag/NiAl(110) are also important parts of this study.« less
Chin, Ya-Huei Cathy; Buda, Corneliu; Neurock, Matthew; Iglesia, Enrique
2011-10-12
Kinetic and isotopic data and density functional theory treatments provide evidence for the elementary steps and the active site requirements involved in the four distinct kinetic regimes observed during CH(4) oxidation reactions using O(2), H(2)O, or CO(2) as oxidants on Pt clusters. These four regimes exhibit distinct rate equations because of the involvement of different kinetically relevant steps, predominant adsorbed species, and rate and equilibrium constants for different elementary steps. Transitions among regimes occur as chemisorbed oxygen (O*) coverages change on Pt clusters. O* coverages are given, in turn, by a virtual O(2) pressure, which represents the pressure that would give the prevalent steady-state O* coverages if their adsorption-desorption equilibrium was maintained. The virtual O(2) pressure acts as a surrogate for oxygen chemical potentials at catalytic surfaces and reflects the kinetic coupling between C-H and O═O activation steps. O* coverages and virtual pressures depend on O(2) pressure when O(2) activation is equilibrated and on O(2)/CH(4) ratios when this step becomes irreversible as a result of fast scavenging of O* by CH(4)-derived intermediates. In three of these kinetic regimes, C-H bond activation is the sole kinetically relevant step, but occurs on different active sites, which evolve from oxygen-oxygen (O*-O*), to oxygen-oxygen vacancy (O*-*), and to vacancy-vacancy (*-*) site pairs as O* coverages decrease. On O*-saturated cluster surfaces, O*-O* site pairs activate C-H bonds in CH(4) via homolytic hydrogen abstraction steps that form CH(3) groups with significant radical character and weak interactions with the surface at the transition state. In this regime, rates depend linearly on CH(4) pressure but are independent of O(2) pressure. The observed normal CH(4)/CD(4) kinetic isotope effects are consistent with the kinetic-relevance of C-H bond activation; identical (16)O(2)-(18)O(2) isotopic exchange rates in the presence or absence of CH(4) show that O(2) activation steps are quasi-equilibrated during catalysis. Measured and DFT-derived C-H bond activation barriers are large, because of the weak stabilization of the CH(3) fragments at transition states, but are compensated by the high entropy of these radical-like species. Turnover rates in this regime decrease with increasing Pt dispersion, because low-coordination exposed Pt atoms on small clusters bind O* more strongly than those that reside at low-index facets on large clusters, thus making O* less effective in H-abstraction. As vacancies (*, also exposed Pt atoms) become available on O*-covered surfaces, O*-* site pairs activate C-H bonds via concerted oxidative addition and H-abstraction in transition states effectively stabilized by CH(3) interactions with the vacancies, which lead to much higher turnover rates than on O*-O* pairs. In this regime, O(2) activation becomes irreversible, because fast C-H bond activation steps scavenge O* as it forms. Thus, O* coverages are set by the prevalent O(2)/CH(4) ratios instead of the O(2) pressures. CH(4)/CD(4) kinetic isotope effects are much larger for turnovers mediated by O*-* than by O*-O* site pairs, because C-H (and C-D) activation steps are required to form the * sites involved in C-H bond activation. Turnover rates for CH(4)-O(2) reactions mediated by O*-* pairs decrease with increasing Pt dispersion, as in the case of O*-O* active structures, because stronger O* binding on small clusters leads not only to less reactive O* atoms, but also to lower vacancy concentrations at cluster surfaces. As O(2)/CH(4) ratios and O* coverages become smaller, O(2) activation on bare Pt clusters becomes the sole kinetically relevant step; turnover rates are proportional to O(2) pressures and independent of CH(4) pressure and no CH(4)/CD(4) kinetic isotope effects are observed. In this regime, turnover rates become nearly independent of Pt dispersion, because the O(2) activation step is essentially barrierless. In the absence of O(2), alternate weaker oxidants, such as H(2)O or CO(2), lead to a final kinetic regime in which C-H bond dissociation on *-* pairs at bare cluster surfaces limit CH(4) conversion rates. Rates become first-order in CH(4) and independent of coreactant and normal CH(4)/CD(4) kinetic isotope effects are observed. In this case, turnover rates increase with increasing dispersion, because low-coordination Pt atoms stabilize the C-H bond activation transition states more effectively via stronger binding to CH(3) and H fragments. These findings and their mechanistic interpretations are consistent with all rate and isotopic data and with theoretical estimates of activation barriers and of cluster size effects on transition states. They serve to demonstrate the essential role of the coverage and reactivity of chemisorbed oxygen in determining the type and effectiveness of surface structures in CH(4) oxidation reactions using O(2), H(2)O, or CO(2) as oxidants, as well as the diversity of rate dependencies, activation energies and entropies, and cluster size effects that prevail in these reactions. These results also show how theory and experiments can unravel complex surface chemistries on realistic catalysts under practical conditions and provide through the resulting mechanistic insights specific predictions for the effects of cluster size and surface coordination on turnover rates, the trends and magnitude of which depend sensitively on the nature of the predominant adsorbed intermediates and the kinetically relevant steps.
Surface states and annihilation characteristics of positrons trapped at the oxidized Cu(100) surface
NASA Astrophysics Data System (ADS)
Fazleev, N. G.; Weiss, A. H.
2013-06-01
In this work we present the results of theoretical studies of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the oxidized Cu(100) surface under conditions of high oxygen coverage. Oxidation of the Cu(100) surface has been studied by performing an ab-initio investigation of the stability and electronic structure of the Cu(100) missing row reconstructed surface at various on-surface and subsurface oxygen coverages ranging from 0.5 to 1.5 monolayers using density functional theory (DFT). All studied structures have been found to be energetically more favorable as compared to structures formed by purely on-surface oxygen adsorption. The observed decrease in the positron work function when oxygen atoms occupy on-surface and subsurface sites has been attributed to a significant charge redistribution within the first two layers, buckling effects within each layer and an interlayer expansion. The computed positron binding energy, positron surface state wave function, and annihilation probabilities of the surface trapped positrons with relevant core electrons demonstrate their sensitivity to oxygen coverage, atomic structure of the topmost layers of surfaces, and charge transfer effects. Theoretical results are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy (PAES). The results presented provide an explanation for the changes observed in the probability of annihilation of surface trapped positrons with Cu 3p core-level electrons as a function of annealing temperature.
Adsorption and Dissociation of CO2 on Ru(0001)
2017-01-01
The adsorption and dissociation of carbon dioxide on a Ru(0001) single crystal surface was investigated by reflection–absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) spectroscopy for CO2 adsorbed at 85 K. RAIRS spectroscopy shows that the adsorption of CO2 on a Ru(0001) single crystal is partially dissociative, resulting in CO2 and CO. The CO vibrational mode was also observed to split into two distinct modes, indicating two general populations of CO present at the surface. Furthermore, a time-dependent blue-shift is observed, which is characteristic of increasing CO surface coverage. TPD showed that coverages of up to 0.3 ML were obtained, and no evidence for chemisorption of oxygen on ruthenium was found. PMID:28413569
First-Principles Study of Mo Segregation in MoNi(111): Effects of Chemisorbed Atomic Oxygen
Yu, Yanlin; Xiao, Wei; Wang, Jianwei; Wang, Ligen
2015-01-01
Segregation at metal alloy surfaces is an important issue because many electrochemical and catalytic properties are directly correlated to the surface composition. We have performed density functional theory calculations for Mo segregation in MoNi(111) in the presence of chemisorbed atomic oxygen. In particular, the coverage dependence and possible adsorption-induced segregation phenomena are addressed by investigating segregation energies of the Mo atom in MoNi(111). The theoretical calculated results show that the Mo atom prefers to be embedded in the bulk for the clean MoNi(111), while it segregates to the top-most layer when the oxygen coverage is thicker than 1/9 monolayer (ML). Furthermore, we analyze the densities of states for the clean and oxygen-chemisorbed MoNi(111), and see a strong covalent bonding between Mo d-band states and O p-states. The present study provides valuable insight for exploring practical applications of Ni-based alloys as hydrogen evolution electrodes. PMID:28787811
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Da-Jiang; Evans, James W.
An accurate description of oxygen dissociation pathways and kinetics for various local adlayer environments is key for an understanding not just of the coverage dependence of oxygen sticking, but also of reactive steady states in oxidation reactions. Density functional theory analysis for M(100) surfaces with M=Pd, Rh, and Ni, where O prefers the fourfold hollow adsorption site, does not support the traditional Brundle-Behm-Barker picture of dissociative adsorption onto second-nearest-neighbor hollow sites with an additional blocking constraint. Rather adsorption via neighboring vicinal bridge sites dominates, although other pathways can be active. The same conclusion also applies for M=Pt and Ir, wheremore » oxygen prefers the bridge adsorption site. Statistical mechanical analysis is performed based on kinetic Monte Carlo simulation of a multisite lattice-gas model consistent with our revised picture of adsorption. This analysis determines the coverage and temperature dependence of sticking for a realistic treatment of the oxygen adlayer structure.« less
Polk, Alexa A.; Maul, Timothy M.; McKeel, Daniel T.; Snyder, Trevor A.; Lehocky, Craig A.; Pitt, Bruce; Stolz, Donna Beer; Federspiel, William J.; Wagner, William R.
2014-01-01
Acute respiratory distress syndrome (ARDS) affects nearly 150,000 patients per year in the US, and is associated with high mortality (≈40%) and suboptimal options for patient care. Mechanical ventilation and extracorporeal membrane oxygenation are limited to short-term use due to ventilator-induced lung injury and poor bio-compatibility, respectively. In this report, we describe the development of a biohybrid lung prototype, employing a rotating endothelialized microporous hollow fiber (MHF) bundle to improve blood biocompatibility while MHF mixing could contribute to gas transfer efficiency. MHFs were surface modified with radio frequency glow discharge (RFGD) and protein adsorption to promote endothelial cell (EC) attachment and growth. The MHF bundles were placed in the biohybrid lung prototype and rotated up to 1,500 revolutions per minute (rpm) using speed ramping protocols to condition ECs to remain adherent on the fibers. Oxygen transfer, thrombotic deposition, and EC p-selectin expression were evaluated as indicators of biohybrid lung functionality and biocompatibility. A fixed aliquot of blood in contact with MHF bundles rotated at either 250 or 750 rpm reached saturating pO2 levels more quickly with increased rpm, supporting the concept that fiber rotation would positively contribute to oxygen transfer. The presence of ECs had no effect on the rate of oxygen transfer at lower fiber rpm, but did provide some resistance with increased rpm when the overall rate of mass transfer was higher due to active mixing. RFGD followed by fibronectin adsorption on MHFs facilitated near confluent EC coverage with minimal p-selectin expression under both normoxic and hyperoxic conditions. Indeed, even subconfluent EC coverage on MHFs significantly reduced thrombotic deposition adding further support that endothelialization enhances, blood biocompatibility. Overall these findings demonstrate a proof-of-concept that a rotating endothelialized MHF bundle enhances gas transfer and biocompatibility, potentially producing safer, more efficient artificial lungs. PMID:20091735
Direct visualization of quasi-ordered oxygen chain structures on Au(110)-(1 × 2)
NASA Astrophysics Data System (ADS)
Hiebel, F.; Montemore, M. M.; Kaxiras, E.; Friend, C. M.
2016-08-01
The Au(110) surface offers unique advantages for atomically-resolved model studies of catalytic oxidation processes on gold. We investigate the adsorption of oxygen on Au(110) using a combination of scanning tunneling microscopy (STM) and density functional theory (DFT) methods. We identify the typical (empty-states) STM contrast resulting from adsorbed oxygen as atomic-sized dark features of electronic origin. DFT-based image simulations confirm that chemisorbed oxygen is generally detected indirectly, from the binding-induced electronic structure modification of gold. STM images show that adsorption occurs without affecting the general structure of the pristine Au(110) missing-row reconstruction. The tendency to form one-dimensional structures is observed already at low coverage (< 0.05 ML), with oxygen adsorbing on alternate sides of the reconstruction ridges. Consistently, calculations yield preferred adsorption on the (111) facets of the reconstruction, on a 3-fold coordination site, with increased stability when adsorbed in chains. Gold atoms with two oxygen neighbors exhibit enhanced electronic hybridization with the O states. Finally, the species observed are reactive to CO oxidation at 200 K and desorption of CO2 leaves a clean and ordered gold surface.
Koonce, Nathan A; Griffin, Robert J; Dings, Ruud P M
2017-12-09
Galectin-1 is a hypoxia-regulated protein and a prognostic marker in head and neck squamous cell carcinomas (HNSCC). Here we assessed the ability of non-peptidic galectin-1 inhibitor OTX008 to improve tumor oxygenation levels via tumor vessel normalization as well as tumor growth inhibition in two human HNSCC tumor models, the human laryngeal squamous carcinoma SQ20B and the human epithelial type 2 HEp-2. Tumor-bearing mice were treated with OTX008, Anginex, or Avastin and oxygen levels were determined by fiber-optics and molecular marker pimonidazole binding. Immuno-fluorescence was used to determine vessel normalization status. Continued OTX008 treatment caused a transient reoxygenation in SQ20B tumors peaking on day 14, while a steady increase in tumor oxygenation was observed over 21 days in the HEp-2 model. A >50% decrease in immunohistochemical staining for tumor hypoxia verified the oxygenation data measured using a partial pressure of oxygen (pO₂) probe. Additionally, OTX008 induced tumor vessel normalization as tumor pericyte coverage increased by approximately 40% without inducing any toxicity. Moreover, OTX008 inhibited tumor growth as effectively as Anginex and Avastin, except in the HEp-2 model where Avastin was found to suspend tumor growth. Galectin-1 inhibitor OTX008 transiently increased overall tumor oxygenation via vessel normalization to various degrees in both HNSCC models. These findings suggest that targeting galectin-1-e.g., by OTX008-may be an effective approach to treat cancer patients as stand-alone therapy or in combination with other standards of care.
NASA Astrophysics Data System (ADS)
Marsh, Anderson L.; Gland, John L.
2003-06-01
The catalytic oxidation of benzene on the Pt(1 1 1) surface has been characterized using temperature-programmed reaction spectroscopy (TPRS) over a wide range of benzene and oxygen coverages. Coadsorbed atomic oxygen and benzene are the primary reactants on the surface during the initial oxidation step. Benzene is oxidized over the 300-500 K range to produce carbon dioxide and water. Carbon-hydrogen and carbon-carbon bond activation are clearly rate-limiting steps for these reactions. Preferential oxidation causes depletion of bridge-bonded benzene, suggesting enhanced reactivity in this bonding configuration. When oxygen is in excess on the surface, all of the surface carbon and hydrogen is oxidized. When benzene is in excess on the surface, hydrogen produced by dehydrogenation is desorbed after all of the surface oxygen has been consumed. Repulsive interactions between benzene and molecular oxygen dominate at low temperatures. Preadsorption of oxygen inhibits adsorption of less reactive benzene in threefold hollow sites. The desorption temperature of this non-reactive chemisorbed benzene decreases and overlaps with the multilayer desorption peak with increasing oxygen exposure. The results presented here provide a clear picture of rate-limiting steps during deep oxidation of benzene on the Pt(1 1 1) surface.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bray, Jacob; Hensley, Alyssa J. R.; Collinge, Greg
The impact of an external electric field on the concerted behavior of oxygen over a multi-faceted catalytic Fe grain is determined via the interpolation of ab initio models of oxygen adsorption on Fe(100), Fe(110), and Fe(111) in the presence of an external electric field. The application of both negative and positive electric fields weaken the adsorption strength for oxygen on all three surface facets, with Fe(110) experiencing the greatest effect. Kinetic models of a multi-faceted catalytic Fe grain show that the average oxygen coverage over the grain surface is reduced under the influence of both a negative and positive electricmore » field, which are consistent with phase diagram results at comparable pressures. Furthermore, we show that there is a weak synergistic effect between a Pd promoter and a positive electric field on the oxygen adsorption energy, i.e. the Pd promoter and electric field combination weaken the oxygen adsorption energy to a greater degree than the simple addition of both components separately. In conclusion, the work shows that the application of an applied external electric field may be a useful tool in fine-tuning chemical properties of Fe-based catalysts in hydrodeoxygenation applications.« less
Bray, Jacob; Hensley, Alyssa J. R.; Collinge, Greg; ...
2018-04-15
The impact of an external electric field on the concerted behavior of oxygen over a multi-faceted catalytic Fe grain is determined via the interpolation of ab initio models of oxygen adsorption on Fe(100), Fe(110), and Fe(111) in the presence of an external electric field. The application of both negative and positive electric fields weaken the adsorption strength for oxygen on all three surface facets, with Fe(110) experiencing the greatest effect. Kinetic models of a multi-faceted catalytic Fe grain show that the average oxygen coverage over the grain surface is reduced under the influence of both a negative and positive electricmore » field, which are consistent with phase diagram results at comparable pressures. Furthermore, we show that there is a weak synergistic effect between a Pd promoter and a positive electric field on the oxygen adsorption energy, i.e. the Pd promoter and electric field combination weaken the oxygen adsorption energy to a greater degree than the simple addition of both components separately. In conclusion, the work shows that the application of an applied external electric field may be a useful tool in fine-tuning chemical properties of Fe-based catalysts in hydrodeoxygenation applications.« less
NASA Technical Reports Server (NTRS)
Spalvins, Talivaldis; Sliney, Harold E.
1994-01-01
A modified dc-diode ion plating system, by utilizing a metallic screen cage as a cathode, is introduced for coating nonconductors such as ceramics. Screen cage ion plating (SCIP) is used to apply Ag and Au lubricating films on aluminum oxide surfaces. This process has excellent ability to coat around corners to produce three-dimensional coverage of the substrate. A dramatic increase in adhesion is achieved when plating is performed in a reactive 50 percent O2 - 50 percent Ar glow discharge compared to the adhesion when plating is performed in 100 percent Ar. The presence of oxygen ion assistance contributes to the excellent adhesion as measured in a pull-type adhesion tester. The Ag and Au film adhesion is significantly increased (less than 70MPa) and generally exceeds the cohesion of the substrate such that portions of the alumina are pulled out.
NASA Astrophysics Data System (ADS)
Weber, A. P.; Caruso, A. N.; Vescovo, E.; Ali, Md. E.; Tarafder, K.; Janjua, S. Z.; Sadowski, J. T.; Oppeneer, P. M.
2013-05-01
The spin-polarized electronic structure of iron octaethylporphyrin (FeOEP) molecules adsorbed on a pristine and on a c(2×2) oxygen-reconstructed Co(100) surface has been analyzed by means of spin-polarized photoemission spectroscopy (SPPES) and first-principles density functional theory with the on-site Coulomb repulsion U term (DFT+U) calculations with and without Van der Waals corrections. The aim is to examine the magnetic exchange mechanism between the FeOEP molecules and the Co(100) substrate in the presence or absence of the oxygen mediator. The results demonstrate that the magnetic coupling from the ferromagnetic substrate to the adsorbed FeOEP molecules is ferromagnetic, whereas, the coupling is antiferromagnetic for the FeOEP on the c(2×2)O/Co(100) system. Spin-resolved partial densities of states extracted from ab initio DFT+U modeling are in fairly good comparison with the electronic spectral densities seen in angle-integrated SPPES energy dispersion curves for submonolayer coverages of FeOEP. Through combined analysis of these spectra and theoretical results, we determine that hybridization of 2p orbitals of N and O with Co 3d orbitals facilitates indirect magnetic exchange interactions between Fe and Co, whereas, a direct Fe-Co interaction involving the Fe dz2 orbital is also found for FeOEP on Co. It is observed through SPPES that the spin polarization of the photoemission-visible molecular overlayers decreases to zero as coverage is increased beyond the submonolayer regime, indicating that only interfacial magnetic coupling is at work. Microspot low-energy electron diffraction and low-energy electron microscopy were performed to characterize the physical order of the molecular coverage, revealing that FeOEP structural domains are orders of magnitude greater in size on c(2×2)O/Co(100) than on clean Co(100), which coincides with reduced scattering from the disorder and sharper features seen in SPPES.
NASA Astrophysics Data System (ADS)
Barman, Sukanta; Menon, Krishnakumar S. R.
2018-04-01
We present here a detailed growth optimization of CoO thin film on Ag(001) involving the effects of different growth parameters on the electronic structure. A well-ordered stoichiometric growth of 5 ML CoO film has been observed at 473 K substrate temperature and 1 × 10-6 mbar oxygen partial pressure. The growth at lower substrate temperature and oxygen partial pressure show non-stoichiometric impurity phases which have been investigated further to correlate the growth parameters with surface electronic structure. The coverage dependent valence band electronic structure of the films grown at optimized condition reveals the presence of interfacial states near the Fermi edge (EF) for lower film coverages. Presence of interfacial states in the stoichiometric films rules out their defect-induced origin. We argue that this is an intrinsic feature of transition metal monoxides like NiO, CoO, MnO in the low coverage regime.
NASA Technical Reports Server (NTRS)
Roder, H. M.
1974-01-01
Information is presented on instrumentation for density measurement, liquid level measurement, quantity gauging, and phase measurement. Coverage of existing information directly concerned with oxygen was given primary emphasis. A description of the physical principle of measurement for each instrumentation type is included. The basic materials of construction are listed if available from the source document for each instrument discussed. Cleaning requirements, procedures, and verification techniques are included.
Understanding the pseudocapacitance of RuO2 from joint density functional theory
NASA Astrophysics Data System (ADS)
Zhan, Cheng; Jiang, De-en
2016-11-01
Pseudocapacitors have been experimentally studied for many years in electric energy storage. However, first principles understanding of the pseudocapacitive behavior is still not satisfactory due to the complexity involved in modeling electrochemistry. In this paper, we applied joint density functional theory (JDFT) to simulate the pseudocapacitive behavior of RuO2, a prototypical material, in a model electrolyte. We obtained from JDFT a capacitive curve which showed a redox peak position comparable to that in the experimental cyclic voltammetry (CV) curve. We found that the experimental turning point from double-layer to pseudocapacitive charge storage at low scan rates could be explained by the hydrogen adsorption at low coverage. As the electrode voltage becomes more negative, H coverage increases and causes the surface-structure change, leading to bended -OH bonds at the on-top oxygen atoms and large capacitance. This H coverage-dependent capacitance can explain the high pseudocapacitance of hydrous RuO2. Our work here provides a first principles understanding of the pseudocapacitance for RuO2 in particular and for transition-metal oxides in general.
NASA Astrophysics Data System (ADS)
Shinozaki, Kazuma; Morimoto, Yu; Pivovar, Bryan S.; Kocha, Shyam S.
2016-09-01
The impact of Nafion on the oxygen reduction reaction (ORR) activity is studied for Pt/C and Pt-alloy/C catalysts using thin-film rotating disk electrode (TF-RDE) methods in 0.1 M HClO4. Ultrathin uniform catalyst layers and standardized activity measurement protocols are employed to obtain accurate and reproducible ORR activity. Nafion lowers the ORR activity which plateaus with increasing loading on Pt catalysts. Pt particle size is found not to have significant influence on the extent of the SA decrease upon Nafion incorporation. Catalysts using high surface area carbon (HSC) support exhibit attenuated activity loss resulting from lower ionomer coverage on catalyst particles located within the deep pores. The impact of metallic composition on the activity loss due to Nafion incorporation is also discussed.
Adsorption of O_{2} on Ag(111): Evidence of Local Oxide Formation.
Andryushechkin, B V; Shevlyuga, V M; Pavlova, T V; Zhidomirov, G M; Eltsov, K N
2016-07-29
The atomic structure of the disordered phase formed by oxygen on Ag(111) at low coverage is determined by a combination of low-temperature scanning tunneling microscopy and density functional theory. We demonstrate that the previous assignment of the dark objects in STM to chemisorbed oxygen atoms is incorrect and incompatible with trefoil-like structures observed in atomic-resolution images in current work. In our model, each object is an oxidelike ring formed by six oxygen atoms around the vacancy in Ag(111).
Density-functional theory study of the initial oxygen incorporation in Pd(111)
NASA Astrophysics Data System (ADS)
Todorova, Mira; Reuter, Karsten; Scheffler, Matthias
2005-05-01
Pd(111) has recently been shown to exhibit a propensity to form a subnanometer thin surface oxide film already well before a full monolayer coverage of adsorbed O atoms is reached on the surface. Aiming at an atomic-scale understanding of this finding, we study the initial oxygen incorporation into the Pd(111) surface using density-functional theory. We find that oxygen incorporation into the sub-surface region starts at essentially the same coverage as formation of the surface oxide. This implies that the role of sub-surface oxygen should be considered as that of a metastable precursor in the oxidation process of the surface. The mechanisms found to play a role towards the ensuing stabilization of an ordered oxidic structure with a mixed on-surface/sub-surface site occupation follow a clear trend over the late 4d transition metal series, as seen by comparing our data to previously published studies concerned with oxide formation at the basal surface of Ru, Rh, and Ag. The formation of a linearly aligned O-TM-O trilayered structure (TM=Ru,Rh,Pd,Ag) , together with an efficient coupling to the underlying substrate seem to be key ingredients in this respect.
NASA Astrophysics Data System (ADS)
Boulter, J. E.; Morgan, C. G.; Marschall, J.
2006-05-01
Remote observations of PMCs have become more sophisticated and have increased in geographic and temporal coverage, while numerical models have advanced in detail and predictive power. Together, these advances enable new questions of PMC morphology, optical properties, and microphysical processes in their formation and dissipation. Laboratory investigations also advance this understanding, simulating physical and chemical processes unique to this atmospheric region under comparable conditions. In this work, ice deposition experiments in the presence of microwave discharge-dissociated molecular oxygen suggest heterogeneous interactions between dangling OH bonds on the ice surface and atomic oxygen. Ice films deposited on a gold substrate at temperatures of 115, 130, and 140 K from oxygen/water gas mixtures representative of the summertime polar mesosphere exhibit infrared absorption features characteristic of dangling bonds, whereas films grown in the presence of atomic oxygen do not. Dangling bond spectral features are shown to diminish rapidly when the microwave discharge is activated during ice deposition. Similar decreases were not seen when the gas stream was heated or when the ice film was slowly annealed from 130 to 160 K. One interpretation of these results is that atomic oxygen binds to dangling bond sites during ice growth, a phenomenon that may also occur during the formation of ice particles observed just below the cold summertime mesopause.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shinozaki, Kazuma; Morimoto, Yu; Pivovar, Bryan S.
The impact of Nafion on the oxygen reduction reaction (ORR) activity is studied for Pt/C and Pt-alloy/C catalysts using thin-film rotating disk electrode (TF-RDE) methods in 0.1 M HClO4. Ultrathin uniform catalyst layers and standardized activity measurement protocols are employed to obtain accurate and reproducible ORR activity. Nafion lowers the ORR activity which plateaus with increasing loading on Pt catalysts. Pt particle size is found not to have significant influence on the extent of the SA decrease upon Nafion incorporation. Catalysts using high surface area carbon (HSC) support exhibit attenuated activity loss resulting from lower ionomer coverage on catalyst particlesmore » located within the deep pores. The impact of metallic composition on the activity loss due to Nafion incorporation is also discussed.« less
The effect of oxygen vacancies on the binding interactions of NH3 with rutile TiO2(110) -1×1
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Boseong; Li, Zhenjun; Kay, Bruce D.
2012-11-21
A series of NH3 temperature-programmed desorption (TPD) spectra was taken after the NH3 dose at 70 K on rutile TiO2(110)-1×1 surfaces with the oxygen vacancy (VO) concentrations of ~0% (p-TiO2) and 5% (r-TiO2), respectively, to study the effect of VO’s on the desorption energy of NH3 as a function of the coverage, θ. Our results show that at zero coverage limit, the desorption energy of NH3 on r-TiO2 is 115 kJ/mol, which is 10 kJ/mol less than that on p-TiO2. The desorption energy from the Ti4+ sites decreases with increasing θ due to the repulsive NH3 - NH3 interactions andmore » approaches ~ 55 kJ/mol upon the saturation of Ti4+ sites (θ = 1 monolayer, ML) on both p- and r-TiO2. The absolute saturation coverage is determined to be about 10% smaller on r-TiO2 than that on p-TiO2. Further, the trailing edges of the NH3 TPD spectra on the hydroxylated TiO2(110) (h-TiO2) appear to be the same as that on r-TiO2 while those on oxidized TiO2(110) (o-TiO2) shift to higher temperatures. We present the detailed analysis of the results and reconcile the observed differences based on the repulsive adsorbate-adsorbate interactions between neighboring NH3 molecules and the surface charge associated with the presence of VO’s. Besides NH3, no other reaction products are observed in the TPD spectra.« less
NASA Astrophysics Data System (ADS)
Flanagan, Harold Patrick
A major issue in the process of predicting the future position of satellites in low earth orbit (LEO) is that the drag coefficient of a satellite is generally not precisely known throughout the satellite's lifespan. One reason for this problem is that as a satellite travels through the Earth's thermosphere, variations in the composition of the thermosphere directly affect the drag coefficient of the satellite. The greatest amount of uncertainty in the drag coefficient from these variations in the thermosphere comes from the amount of atomic oxygen that covers the satellites surface as the satellite descends to lower altitudes. This percent surface coverage of atomic oxygen directly affects the interaction between the surface of the satellite and the gas through which it is passing. The work performed in this thesis determines the drag coefficients of the ANDE-2 satellites over their life spans by using satellite laser ranging (SLR) data of the ANDE-2 satellites in unison with gas-surface interaction equations. The fractional coverage of atomic oxygen is determined by using empirically determined data and semi-empirical models that attempt to predict the fractional coverage of oxygen relative to the composition of the atmosphere. These drag coefficients are then used to determine the atmospheric densities experienced by these satellites over various days, so that inaccuracies in the atmospheric models can be observed. The drag coefficients of the ANDE-2 satellites decrease throughout the satellites' life, and vary most due to changes in the temperature and density of the atmosphere. The greatest uncertainty in the atmosphere's composition occurs at lower altitudes at the end of ANDE-2's life.
Coverage of STS-104 Launch Coverage of Flight Controllers in MCC.
2001-07-12
JSC2001-E-21338 (12 July 2001) --- Robert Gest (left), with United Space Alliance (USA); Steven A. Hawley, deputy director of flight crew operations; and Alan L. (Lee) Briscoe, chief engineer for the Mission Operations Directorate, watch their monitors at the MOD console in the shuttle flight control room (WFCR) as the external tank oxygen vent hood is raised and retracted minutes prior to the launch of the Space Shuttle Atlantis.
Effect Of Water On Permeation By Hydrogen
NASA Technical Reports Server (NTRS)
Tomazic, William A.; Hulligan, David
1988-01-01
Water vapor in working fluid equilibrates with permeability-reducing oxides in metal parts. Report describes study of effects of water on permeation of heater-head tubes by hydrogen in Stirling engine. Experiments performed to determine minimum concentration of oxygen and/or oxygen-bearing gas maintaining oxide coverage adequate for low permeability. Tests showed 750 ppm or more of water effective in maintaining stable, low permeability.
Dynamics, Stability, and Adsorption States of Water on Oxidized RuO 2 (110)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nguyen, Manh-Thuong; Mu, Rentao; Cantu, David C.
Identifying and understanding how excess oxygen atoms affect the adsorption of water on metal oxides is crucial for their use in water splitting. Here, by means of high-resolution scanning tunneling microscopy and density-functional calculations, we show that excess oxygen atoms on the stoichiometric RuO2(110) significantly change the clustering, conformation, and deprotonation equilibrium of adsorbed water. We considered two reactive scenarios during which the stoichiometric surface was exposed to: (i) first to oxygen followed by water, and (ii) first to water followed by oxygen. In both cases the [OH-OH] complex on Ru rows is the dominant species, showing a significant differencemore » from water-only adsorption on the stoichiometric surface in which the [OH-H2O] species is found to be prevalent. Surface reactivity at almost full O coverage is also addressed; there we show that site selectivity of the surface for H adsorption and dissociation of H2O is hindered, notwithstanding the increase of the dynamical motion of both species. We found that the work function of RuO2 can serve as a descriptor for the reactivity of this surface to water and its constituents.« less
Methanol oxidation on stoichiometric and oxygen-rich RuO2(110).
Rai, Rahul; Weaver, Jason F
2017-07-26
We used temperature-programmed reaction spectroscopy (TPRS) to investigate the adsorption and oxidation of methanol on stoichiometric and O-rich RuO 2 (110) surfaces. We find that the complete oxidation of CH 3 OH is strongly preferred on stoichiometric RuO 2 (110) during TPRS for initial CH 3 OH coverages below ∼0.33 ML (monolayer), and that partial oxidation to mainly CH 2 O becomes increasingly favored with increasing CH 3 OH coverage from 0.33 to 1.0 ML. We present evidence that an adsorbed CH 2 O 2 species serves as the key intermediate to complete oxidation and that CH 2 O 2 formation is intrinsically facile but becomes limited by the availability of bridging O-atoms on stoichiometric RuO 2 (110) at initial CH 3 OH coverages above 0.33 ML. We show that methanol molecules adsorbed in excess of 0.33 ML dehydrogenate to mainly CH 2 O and desorb during TPRS, with adsorbed CH 3 O groups mediating the evolution of both CH 2 O and CH 3 OH. We find that O-rich RuO 2 (110) surfaces are also highly active toward methanol oxidation and that selectivity toward the complete oxidation of methanol increases markedly with increasing coverage of on-top O-atoms (O ot ) on RuO 2 (110). Our results demonstrate that CH 3 OH species adsorbed within O ot -rich domains react efficiently during TPRS, in parallel with reaction of CH 3 OH adsorbed initially on cus-Ru sites. The data suggests that the facile hydrogenation of O ot atoms and the resulting desorption of H 2 O at low-temperature (<∼400 K) provides an efficient pathway for restoring reactive O-atoms and thereby promoting complete oxidation of methanol on the O-rich RuO 2 (110) surface.
LaGraff, John R; Chu-LaGraff, Quynh
2006-05-09
Unlabeled primary immunoglobulin G (IgG) antibodies and its F(ab')2 and Fc fragments were attached to oxygen-plasma-cleaned glass substrates using either microcontact printing (MCP) or physical adsorption during bath application from dilute solutions. Fluorescently labeled secondary IgGs were then bound to surface-immobilized IgG, and the relative surface coverage was determined by measuring the fluorescence intensity. Results indicated that the surface coverage of IgG increased with increasing protein solution concentration for both MCP and bath-applied IgG and that a greater concentration of IgG was transferred to a glass substrate using MCP than during physisorption during bath applications. Scanning force microscopy (SFM) showed that patterned MCP IgG monolayers were 5 nm in height, indicating that IgG molecules lie flat on the substrate. After incubation with a secondary IgG, the overall line thickness increased to around 15 nm, indicating that the secondary IgG was in a more vertical orientation with respect to the substrate. The surface roughness of these MCP patterned IgG bilayers as measured by SFM was observed to increase with increasing surface coverage. Physisorption of IgG to both unmodified patterned polydimethylsiloxane (PDMS) stamps and plasma-cleaned glass substrates was modeled by Langmuir adsorption kinetics yielding IgG binding constants of K(MCP) = 1.7(2) x 10(7) M(-1) and K(bath) = 7.8(7) x 10(5) M(-1), respectively. MCP experiments involving primary F(ab')2 and Fc fragments incubated in fluorescently labeled fragment-specific secondary IgGs were carried out to test for the function and orientation of IgG. Finally, possible origins of MCP stamping defects such as pits, pull outs, droplets, and reverse protein transfer are discussed.
Chemical composition and reactivity of water on hexagonal Pt-group metal surfaces.
Shavorskiy, A; Gladys, M J; Held, G
2008-10-28
The dissociation behaviour and valence-electronic structure of water adsorbed on clean and oxygen-covered Ru{0001}, Rh{111}, Pd{111}, Ir{111} and Pt{111} surfaces has been studied by high-resolution X-ray photoelectron spectroscopy with the aim of identifying similarities and trends within the Pt-group metals. On average, we find higher reactivity for the 4d metals (Ru, Rh, Pd) as compared to 5d (Ir, Pt), which is correlated with characteristic shifts in the 1b(1) and 3a(1) molecular orbitals of water. Small amounts of oxygen (< 0.2 ML) induce dissociation of water on all five surfaces, for higher coverages (> 0.25 ML) only intact water is observed. Under UHV conditions these higher coverages can only be reached on the 4d metals, the 5d metals are, therefore, not passivated.
Methanethiol chemistry on TiO 2-supported Ni clusters
NASA Astrophysics Data System (ADS)
Ozturk, O.; Park, J. B.; Black, T. J.; Rodriguez, J. A.; Hrbek, J.; Chen, D. A.
2008-10-01
The thermal decomposition of methanethiol on Ni clusters grown on TiO 2(1 1 0) was studied by temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS) and low energy ion scattering (LEIS). On all of the Ni surfaces investigated, methane and hydrogen were observed as gaseous products in the TPD experiments, and the only sulfur-containing species that desorbed from the surface was methanethiol itself at low temperatures. The two pathways for methanethiol reaction were hydrodesulfurization to produce methane and nonselective decomposition, which leaves atomic carbon and sulfur on the surface. From high resolution XPS studies, methyl thiolate was identified as the surface intermediate for reaction on TiO 2 and on all of the Ni surfaces investigated, similar to what is observed on single-crystal Ni surfaces. However, the binding sites for methyl thiolate on the 1 ML (monolayer) Ni clusters were different from those on the Ni clusters at coverages of 2.5 ML and higher, based on the S(2p) binding energies for methyl thiolate. No distinct changes in activity or selectivity were observed for the smaller Ni clusters grown at low coverage compared to the more film-like Ni surfaces other than what could be accounted for by changes in total surface area. Interactions between the Ni clusters and the TiO 2 support had two main effects on chemical activity. First, carbon was oxidized by oxygen from the TiO 2 lattice to produce CO at temperatures above 800 K. Second, annealing induced encapsulation of the Ni clusters by reduced TiO x and chemisorbed oxygen. At 800 K, the Ni clusters were totally encapsulated, resulting in a complete loss of methanethiol activity; partial encapsulation at 700 K caused a smaller decrease in activity accompanied by increased oxidation of carbon by lattice oxygen.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krix, David; Nienhaus, Hermann, E-mail: hermann.nienhaus@uni-due.de
2014-08-21
Thin potassium films grown on Si(001) substrates are used to measure internal chemicurrents and the external emission of exoelectrons simultaneously during adsorption of molecular oxygen on K surfaces at 120 K. The experiments clarify the dynamics of electronic excitations at a simple metal with a narrow valence band. X-ray photoemission reveals that for exposures below 5 L almost exclusively peroxide K{sub 2}O{sub 2} is formed, i.e., no dissociation of the molecule occurs during interaction. Still a significant chemicurrent and a delayed exoelectron emission are detected due to a rapid injection of unoccupied molecular levels below the Fermi level. Since themore » valence band width of potassium is approximately equal to the potassium work function (2.4 eV) the underlying mechanism of exoemission is an Auger relaxation whereas chemicurrents are detected after resonant charge transfer from the metal valence band into the injected level. The change of the chemicurrent and exoemission efficiencies with oxygen coverage can be deduced from the kinetics of the reaction and the recorded internal and external emission currents traces. It is shown that the non-adiabaticity of the reaction increases with coverage due to a reduction of the electronic density of states at the surface while the work function does not vary significantly. Therefore, the peroxide formation is one of the first reaction systems which exhibits varying non-adiabaticity and efficiencies during the reaction. Non-adiabatic calculations based on model Hamiltonians and density functional theory support the picture of chemicurrent generation and explain the rapid injection of hot hole states by an intramolecular motion, i.e., the expansion of the oxygen molecule on the timescale of a quarter of a vibrational period.« less
Liu, Hai-Xia; Tian, Na; Ye, Jin-Yu; Lu, Bang-An; Ren, Jie; Huangfu, Zhi-Chao; Zhou, Zhi-You; Sun, Shi-Gang
2014-01-01
This study focuses on CO adsorption at tetrahexahedral Pt nanocrystals (THH Pt NCs) by using cyclic voltammetry and in situ FTIR spectroscopy. Since the electrochemically prepared THH Pt NCs in this study are enclosed by {730} facets which could be considered by a subfacet configuration of 2{210} + {310}, we have also studied CO adsorption on the interrelated Pt(310) and Pt(210) single crystal electrodes as a comparison. Cyclic voltammetry results demonstrated that CO adsorbs dominantly on the (100) sites of THH Pt NCs at low CO coverage (θ(CO)≤ 0.135), while on both (100) and (110) sites at higher CO coverage. On ordered Pt(310) and Pt(210), i.e. they were flame annealed and then cooled in H(2) + Ar, CO adsorption also illustrates relative priority on (100) sites at low CO coverage; while at high CO coverage or on oxygen-disordered Pt(310) and Pt(210) when they were cooled in air after flame annealing, the adsorption of CO presents a weak preference on (100) sites of Pt(310) and even no preference at all on (100) sites of Pt(210). In situ FTIR spectroscopic studies illustrated that CO adsorption on THH Pt NCs yields anomalous infrared effects (AIREs), which are depicted by the Fano-like IR feature on a dense distribution (60 μm(-2)) and the enhancement of abnormal IR absorption on a sparse distribution (22 μm(-2)) of THH Pt NCs on glassy carbon substrate. Systematic investigation of CO coverage dependence of IR features revealed that, on THH Pt NCs, the IR band center (ν(COL)) of linearly bonded CO (COL) is rapidly shifted to higher wavenumbers along with the increase of CO coverage to 0.184, yielding a fast linear increase rate with a high slope (dν(COL)/dθ(IR)(CO) = 219 cm(-1)); when θ > 0.184, the increase of ν(COL) with θCO slows down and deviates drastically from linearity. In contrast, the ν(COL) on the ordered Pt(310) electrode maintains a linear increase with θ(IR)(CO) for the whole range of θ(IR)(CO) variation, and gives a much smaller increase rate of slope 74.3 cm(-1). The significant differences in CO adsorption behavior on THH Pt NCs and on interrelated Pt single crystal planes demonstrated clearly the unique properties of nanoparticles enclosed by high-index facets.
NASA Astrophysics Data System (ADS)
Samin, Adib J.; Taylor, Christopher D.
2017-11-01
The design of corrosion resistant zircalloys is important for a variety of technological applications ranging from medicine to the nuclear industry. Since corrosion resistance is mainly attributed to the formation of a surface oxide layer, developing a detailed understanding of this process may assist in future corrosion resistance design. In this work, we conduct a systematic multi-scale investigation of the early stages of oxide formation. This was accomplished by first using a database of fully relaxed DFT calculations to build a cluster-expansion description of the potential function. The developed potential was reasonably good at predicting DFT energies as evidenced by the cross-validation score of 4.4 meV/site. The effective cluster expansion parameters were indicative of repulsive adsorbate interactions in the adlayer in agreement with the literature. The potential then allowed for a systematic investigation of the oxygen configurations on the Zr(0001) surface via Monte Carlo simulations. The adsorption energy was recorded as a function of coverage and an increasing trend was observed in agreement with DFT predictions and the repulsive nature of interactions in the adlayer. The convex hull diagram was recorded indicating the most stable configuration to occur around a coverage of 0.6 ML. The adsorption isotherm was also recorded and contrasted for two temperatures relevant for different applications.
Solid oxide fuel cell cathode with oxygen-reducing layer
DOE Office of Scientific and Technical Information (OSTI.GOV)
Surdoval, Wayne A.; Berry, David A.; Shultz, Travis
The disclosure provides a SOFC comprised of an electrolyte, anode, and cathode, where the cathode comprises an MIEC and an oxygen-reducing layer. The oxygen-reducing layer is in contact with the MIEC, and the MIEC is generally between and separating the oxygen-reducing layer and the electrolyte. The oxygen-reducing layer is comprised of single element oxides, single element carbonates, or mixtures thereof, and has a thickness of less than about 30 nm. In a particular embodiment, the thickness is less than 5 nm. In another embodiment, the thickness is about 3 monolayers or less. The oxygen-reducing layer may be a continuous filmmore » or a discontinuous film with various coverage ratios. The oxygen-reducing layer at the thicknesses described may be generated on the MIEC surface using means known in the art such as, for example, ALD processes.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ciapina, Eduardo G.; Lopes, Pietro P.; Subbaraman, Ram
2015-11-01
We use the rotating ring disk (RRDE) method to study activity-selectivity relationships for the oxygen reduction reaction (ORR) on Pt(111) modified by various surface coverages of adsorbed CNad (ΘCNad). The results demonstrate that small variations in ΘCNad have dramatic effect on the ORR activity and peroxide production, resulting in “volcano-like” dependence with an optimal surface coverage of ΘCNad = 0.3 ML. These relationships can be simply explained by balancing electronic and ensemble effects of co-adsorbed CNad and adsorbed spectator species from the supporting electrolytes, without the need for intermediate adsorption energy arguments. Although this study has focused on the Pt(111)-CNad/H2SO4more » interface, the results and insight gained here are invaluable for controlling another dimension in the properties of electrochemical interfaces.« less
Optical conductivity of partially oxidized graphene from first principles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nasehnia, F., E-mail: f.nasehnia@gmail.com; Seifi, M., E-mail: Seifi@guilan.ac.ir
2015-07-07
We investigate the geometry, electronic structure, and optical properties of partially oxidized graphene using density functional theory. Our calculations show that oxygen atoms are chemisorbed on graphene plane and distort carbon atoms vertically, with almost no change in the in-plane structure. The ground state configurations for different oxygen coverages ranging from 2% to 50% (O/C ratio) are calculated and show the strong tendency of oxygen adatoms to aggregate and form discrete islands on graphene plane. It is found that the opened band gap due to oxygen functionalization depends on the oxygen density and the adsorption configuration. The gap is notmore » significant for oxygen densities lower than 8%. The optical conductivities are calculated in the infrared, visible, and ultraviolet regions and show different characteristic features depending on the degree of oxidation. These results imply that optical measurement techniques can be employed to monitor oxidation (or reduction) process as contact-free methods.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henderson, Michael A.
2013-10-17
The chemical and photochemical properties of three butene molecules (cis-butene, trans-butene and isobutene) were explored on the clean rutile TiO 2(110) surface using temperature programmed desorption (TPD) and photon simulated desorption (PSD). At the low coverage limit, trans-butene was the most strongly bound butene on the TiO 2(110) surface, desorbing at ~ 210 K, however increased intermolecular repulsions between trans-butene molecules at higher coverage diminished its binding. Both cis-butene and isobutene saturated the first layer on TiO 2(110) at a coverage of ~0.50 ML in a single TPD feature at 184 and 192 K, respectively. In contrast, the maximum coveragemore » that trans-butene could achieve in its 210 K peak was ~1/3 ML, with higher coverages resulting a low temperature desorption at ~137 K. Coverages of these molecules above 0.50 ML resulted in population of second layer and multilayer states. The instability of trans-butene at a coverage of 0.5 ML on the surface was linked to the inversion center in its symmetry. In the absence of coadsorbed oxygen, the primary photochemical pathway of each butene molecule on TiO 2(110) was photodesorption. The photoactivities of these molecules on TiO 2(110) at an initial coverage of 0.50 ML followed the trend: isobutene > cis-butene > trans-butene. In contrast, the photoactivities of low coverages of cis-butene and trans-butene exceeded those measured at 0.50 ML. These data suggest that intermolecular interactions (repulsions) play a significant role in diminishing the photoactivities of weakly bound molecules on TiO 2 photocatalysts. Work reported here was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Chemical Sciences, Geosciences, and Biosciences, and performed in the Williams R. Wiley Environmental Molecular Science Laboratory (EMSL), a Department of Energy user facility funded by the Office of Biological and Environmental Research. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for the U.S. Department of Energy by the Battelle Memorial Institute under contract DEAC05-76RL01830.« less
Thermal effects on electronic properties of CO/Pt(111) in water.
Duan, Sai; Xu, Xin; Luo, Yi; Hermansson, Kersti; Tian, Zhong-Qun
2013-08-28
Structure and adsorption energy of carbon monoxide molecules adsorbed on the Pt(111) surfaces with various CO coverages in water as well as work function of the whole systems at room temperature of 298 K were studied by means of a hybrid method that combines classical molecular dynamics and density functional theory. We found that when the coverage of CO is around half monolayer, i.e. 50%, there is no obvious peak of the oxygen density profile appearing in the first water layer. This result reveals that, in this case, the external force applied to water molecules from the CO/Pt(111) surface almost vanishes as a result of the competitive adsorption between CO and water molecules on the Pt(111) surface. This coverage is also the critical point of the wetting/non-wetting conditions for the CO/Pt(111) surface. Averaged work function and adsorption energy from current simulations are consistent with those of previous studies, which show that thermal average is required for direct comparisons between theoretical predictions and experimental measurements. Meanwhile, the statistical behaviors of work function and adsorption energy at room temperature have also been calculated. The standard errors of the calculated work function for the water-CO/Pt(111) interfaces are around 0.6 eV at all CO coverages, while the standard error decreases from 1.29 to 0.05 eV as the CO coverage increases from 4% to 100% for the calculated adsorption energy. Moreover, the critical points for these electronic properties are the same as those for the wetting/non-wetting conditions. These findings provide a better understanding about the interfacial structure under specific adsorption conditions, which can have important applications on the structure of electric double layers and therefore offer a useful perspective for the design of the electrochemical catalysts.
NASA Astrophysics Data System (ADS)
Mortuza, S. M.; Taufique, M. F. N.; Banerjee, Soumik
2017-02-01
The power conversion efficiency (PCE) of planar perovskite solar cells (PSCs) has reached up to ∼20%. However, structural and chemicals defects that lead to hysteresis in the perovskite based thin film pose challenges. Recent work has shown that thin films of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) deposited on the photo absorption layer, using solution processing techniques, minimize surface pin holes and defects thereby increasing the PCE. We developed and employed a multiscale model based on molecular dynamics (MD) and kinetic Monte Carlo (kMC) to establish a relationship between deposition rate and surface coverage on perovskite surface. The MD simulations of PCBMs dispersed in chlorobenzene, sandwiched between (110) perovskite substrates, indicate that PCBMs are deposited through anchoring of the oxygen atom of carbonyl group to the exposed lead (Pb) atom of (110) perovskite surface. Based on rates of distinct deposition events calculated from MD, kMC simulations were run to determine surface coverage at much larger time and length scales than accessible by MD alone. Based on the model, a generic relationship is established between deposition rate of PCBMs and surface coverage on perovskite crystal. The study also provides detailed insights into the morphology of the deposited film.
O'Brien, Megan; Ford, Janet H; Aurora, Sheena K; Govindan, Sriram; Tepper, Deborah E; Tepper, Stewart J
2017-10-01
Cluster headache (CH) is a primary headache disorder associated with low levels of diagnosis and high unmet medical need. The pain attacks, associated anxiety, and fear in anticipation of the attacks are extremely debilitating to a patient with CH. For acute therapy, treatment guidelines recommend inhalation of high flow oxygen during the period of an attack. However, the use of oxygen for treatment of CH remains largely underutilized. The objectives of the study, which covered each of the US states, were to map the current market landscape of medical grade oxygen for use in CH and to develop a cost simulator based on a patient's needs and geography. Desk research was undertaken to obtain price lists and product catalogs from wholesale and retail suppliers of medical grade oxygen across all US states. Base case scenarios for chronic and episodic forms of CH were assumed. A cost simulator was used to calculate the cost of oxygen use using inputs including the state in USA, tank size and price, exacerbations per year, duration of exacerbation, attacks per day, flow rate and duration of flow. Information was also collected to determine if healthcare insurers covered the costs of home oxygen use for CH. Out of the 42 US states where pricing information of medical grade oxygen was available from suppliers, in 38 states the annual cost of high-flow oxygen for a patient with episodic CH was estimated to be <$1000. In 39 states, the annual cost of high-flow oxygen for a patient with chronic CH was estimated to be <$5000. Most of the home oxygen suppliers were familiar with CH and stocked the special non-rebreather masks and regulators necessary for this condition. It was found that many of the private commercial healthcare insurance providers reimbursed the cost of oxygen use for CH. However, the US Centers for Medicare and Medicaid Services (CMS) maintains there is insufficient evidence for coverage and continues to deny coverage for US Medicare and Medicaid patients. Results from our study showed that the current costs for oxygen use as an acute therapy in CH are not prohibitively expensive for patients and healthcare insurance providers. Apart from CMS, many insurers do reimburse the cost of oxygen use for CH. Our study suggests that further research is needed to determine if a lack of physician awareness about treatments and ways to prescribe are barriers for patients to access the high-flow oxygen treatment. © 2017 American Headache Society.
Communication — Modeling polymer-electrolyte fuel-cell agglomerates with double-trap kinetics
Pant, Lalit M.; Weber, Adam Z.
2017-04-14
A new semi-analytical agglomerate model is presented for polymer-electrolyte fuel-cell cathodes. The model uses double-trap kinetics for the oxygen-reduction reaction, which can capture the observed potential-dependent coverage and Tafel-slope changes. An iterative semi-analytical approach is used to obtain reaction rate constants from the double-trap kinetics, oxygen concentration at the agglomerate surface, and overall agglomerate reaction rate. The analytical method can predict reaction rates within 2% of the numerically simulated values for a wide range of oxygen concentrations, overpotentials, and agglomerate sizes, while saving simulation time compared to a fully numerical approach.
Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 1×1
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Boseong; Kay, Bruce D.; Dohnalek, Zdenek
2015-01-15
The reaction of NO with hydroxylated rutile TiO2(110)-1×1 surface (h-TiO2) was investigated as a function of NO coverage using temperature-programmed desorption. Our results show that NO reaction with h-TiO2 leads to formation of NH3 which is observed to desorb at ~ 400 K. Interestingly, the amount of NH3 produced depends nonlinearly on the coverage of NO. The yield increases up to a saturation value of ~1.3×1013 NH3/cm2 at a NO dose of 5×1013 NO/cm2, but subsequently decreases at higher NO doses. Preadsorbed H2O is found to have a negligible effect on the NH3 desorption yield. Additionally, no NH3 is formedmore » in the absence of surface hydroxyls (HOb’s) upon coadsorption of NO and H2O on a stoichiometric TiO2(110) (s-TiO2(110)). Based on these observations, we conclude that nitrogen from NO has a strong preference to react with HOb’s on the bridge-bonded oxygen rows (but not with H2O) to form NH3. The absolute NH3 yield is limited by competing reactions of HOb species with titanium-bound oxygen adatoms to form H2O. Our results provide new mechanistic insight about the interactions of NO with hydroxyl groups on TiO2(110) .« less
Smith, Graham C.
2017-01-01
The modification of electrode surfaces is widely implemented in order to try and improve electron transfer kinetics and surface interactions, most recently using graphene related materials. Currently, the use of ‘as is’ graphene oxide (GO) has been largely overlooked, with the vast majority of researchers choosing to reduce GO to graphene or use it as part of a composite electrode. In this paper, ‘as is’ GO is explored and electrochemically characterized using a range of electrochemical redox probes, namely potassium ferrocyanide(II), N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD), dopamine hydrochloride and epinephrine. Furthermore, the electroanalytical efficacy of GO is explored towards the sensing of dopamine hydrochloride and epinephrine via cyclic voltammetry. The electrochemical response of GO is benchmarked against pristine graphene and edge plane-/basal plane pyrolytic graphite (EPPG and BPPG respectively) alternatives, where the GO shows an enhanced electrochemical/electroanalytical response. When using GO as an electrode material, the electrochemical response of the analytes studied herein deviate from that expected and exhibit altered electrochemical responses. The oxygenated species encompassing GO strongly influence and dominate the observed voltammetry, which is crucially coverage dependent. GO electrocatalysis is observed, which is attributed to the presence of beneficial oxygenated species dictating the response in specific cases, demonstrating potential for advantageous electroanalysis to be realized. Note however, that crucial coverage based regions are observed at GO modified electrodes, owing to the synergy of edge plane sites and oxygenated species. We report the true beneficial electrochemistry of GO, which has enormous potential to be beneficially used in various electrochemical applications ‘as is’ rather than be simply used as a precursor to making graphene and is truly a fascinating member of the graphene family. PMID:29291099
Plastron Respiration Using Commercial Fabrics
Atherton, Shaun; Brennan, Joseph C.; Morris, Robert H.; Smith, Joshua D.E.; Hamlett, Christopher A.E.; McHale, Glen; Shirtcliffe, Neil J.; Newton, Michael I.
2014-01-01
A variety of insect and arachnid species are able to remain submerged in water indefinitely using plastron respiration. A plastron is a surface-retained film of air produced by surface morphology that acts as an oxygen-carbon dioxide exchange surface. Many highly water repellent and hydrophobic surfaces when placed in water exhibit a silvery sheen which is characteristic of a plastron. In this article, the hydrophobicity of a range of commercially available water repellent fabrics and polymer membranes is investigated, and how the surface of the materials mimics this mechanism of underwater respiration is demonstrated allowing direct extraction of oxygen from oxygenated water. The coverage of the surface with the plastron air layer was measured using confocal microscopy. A zinc/oxygen cell is used to consume oxygen within containers constructed from the different membranes, and the oxygen consumed by the cell is compared to the change in oxygen concentration as measured by an oxygen probe. By comparing the membranes to an air-tight reference sample, it was found that the membranes facilitated oxygen transfer from the water into the container, with the most successful membrane showing a 1.90:1 ratio between the cell oxygen consumption and the change in concentration within the container. PMID:28788469
Formic Acid Dissociative Adsorption on NiO(111): Energetics and Structure of Adsorbed Formate
Zhao, Wei; Doyle, Andrew D.; Morgan, Sawyer E.; ...
2017-11-21
Here, the dissociative adsorption of carboxylic acids on oxide surfaces is important for understanding adsorbed carboxylates, which are important as intermediates in catalytic reactions, for the organo-functionalization of oxide surfaces, and in many other aspects of oxide surface chemistry. We present here the first direct experimental measurement of the heat of dissociative adsorption of any carboxylic acid on any single-crystal oxide surface. The enthalpy of the dissociative adsorption of formic acid, the simplest carboxylic acid, to produce adsorbed formate and hydrogen (as a surface hydroxyl) on a (2 × 2)-NiO(111) surface is measured by single crystal adsorption calorimetry. The differentialmore » heat of adsorption decreases with formic acid coverage from 202 to 99 kJ/mol at saturation (0.25 ML). The structure of the adsorbed products is clarified by density functional theory (DFT) calculations, which provide energies in reasonable agreement with the calorimetry. These calculations show that formic acid readily dissociates on both the oxygen and Ni terminations of the octapolar NiO(111) surfaces, donating its acid H to a surface lattice oxygen, while HCOO adsorbs preferentially with bridging-type geometry near the M-O 3/O-M 3 sites. The calculated energetics at low coverages agrees well with experimental data, while larger differences are observed at high coverage (0.25 ML). The large decrease in experimental heat of adsorption with coverage can be brought into agreement with the DFT energies if we assume that both types of octapolar surface terminations (O- and Ni-) are present on the starting surface.« less
Formic Acid Dissociative Adsorption on NiO(111): Energetics and Structure of Adsorbed Formate
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhao, Wei; Doyle, Andrew D.; Morgan, Sawyer E.
Here, the dissociative adsorption of carboxylic acids on oxide surfaces is important for understanding adsorbed carboxylates, which are important as intermediates in catalytic reactions, for the organo-functionalization of oxide surfaces, and in many other aspects of oxide surface chemistry. We present here the first direct experimental measurement of the heat of dissociative adsorption of any carboxylic acid on any single-crystal oxide surface. The enthalpy of the dissociative adsorption of formic acid, the simplest carboxylic acid, to produce adsorbed formate and hydrogen (as a surface hydroxyl) on a (2 × 2)-NiO(111) surface is measured by single crystal adsorption calorimetry. The differentialmore » heat of adsorption decreases with formic acid coverage from 202 to 99 kJ/mol at saturation (0.25 ML). The structure of the adsorbed products is clarified by density functional theory (DFT) calculations, which provide energies in reasonable agreement with the calorimetry. These calculations show that formic acid readily dissociates on both the oxygen and Ni terminations of the octapolar NiO(111) surfaces, donating its acid H to a surface lattice oxygen, while HCOO adsorbs preferentially with bridging-type geometry near the M-O 3/O-M 3 sites. The calculated energetics at low coverages agrees well with experimental data, while larger differences are observed at high coverage (0.25 ML). The large decrease in experimental heat of adsorption with coverage can be brought into agreement with the DFT energies if we assume that both types of octapolar surface terminations (O- and Ni-) are present on the starting surface.« less
NASA Technical Reports Server (NTRS)
Banks, Bruce A. (Inventor)
2008-01-01
Disclosed is a method of producing cones and pillars on polymethylmethacralate (PMMA) optical fibers for glucose monitoring. The method, in one embodiment, consists of using electron beam evaporation to deposit a non-contiguous thin film of aluminum on the distal ends of the PMMA fibers. The partial coverage of aluminum on the fibers is randomly, but rather uniformly distributed across the end of the optical fibers. After the aluminum deposition, the ends of the fibers are then exposed to hyperthermal atomic oxygen, which oxidizes the areas that are not protected by aluminum. The resulting PMMA fibers have a greatly increased surface area and the cones or pillars are sufficiently close together that the cellular components in blood are excluded from passing into the valleys between the cones and pillars. The optical fibers are then coated with appropriated surface chemistry so that they can optically sense the glucose level in the blood sample than that with conventional glucose monitoring.
Miranda, L.E.; Pugh, L.L.
1997-01-01
Juvenile largemouth bass Micropterus salmoides were collected by electrofishing during October through March 1992-1994 from coves (???25 ha) covered with aquatic macrophytes over 1-65% of their area. Mean total length of juvenile largemouth bass was highest in coves with the least vegetated cover, but increase in mean length between October and March was highest in coves having near 20% vegetation coverage. Catch per unit effort decreased between October and March; decreases were least at vegetation coverages near 10-20%, highest at coverages of 5% or less, and intermediate at coverages of 30-65%. By March, these disparate decreases contributed to the formation of a dome-like relationship between vegetation coverage and catch per unit effort. Consumption of fish foods was highest when vegetation coverage was low, but decreased asymptotically as coverage increased; consumption of invertebrate foods increased at low coverage, peaked near 20-30% coverage, and decreased at higher coverage. We suggest that greater length increases and greater abundance at 10-25% vegetation coverage were stimulated by a favorable blend of food availability and cover. Our results support reports that maximum recruitment of largemouth bass occurs at intermediate levels of vegetation coverage, and we further suggests that such increased production is reinforced during winter, when survival, invertebrate consumption, and length increases are highest at intermediate levels of vegetation coverage.
NASA Technical Reports Server (NTRS)
Snyder, Aaron; Banks, Bruce; Miller, Sharon; Stueber, Thomas; Sechkar, Edward
2001-01-01
A numerical procedure is presented to calculate transmittance degradation caused by contaminant films on spacecraft surfaces produced through the interaction of orbital atomic oxygen (AO) with volatile silicones and hydrocarbons from spacecraft components. In the model, contaminant accretion is dependent on the adsorption of species, depletion reactions due to gas-surface collisions, desorption, and surface reactions between AO and silicone producing SiO(x), (where x is near 2). A detailed description of the procedure used to calculate the constituents of the contaminant layer is presented, including the equations that govern the evolution of fractional coverage by specie type. As an illustrative example of film growth, calculation results using a prototype code that calculates the evolution of surface coverage by specie type is presented and discussed. An example of the transmittance degradation caused by surface interaction of AO with deposited contaminant is presented for the case of exponentially decaying contaminant flux. These examples are performed using hypothetical values for the process parameters.
GaAs-oxide interface states - Gigantic photoionization via Auger-like process
NASA Technical Reports Server (NTRS)
Lagowski, J.; Kazior, T. E.; Gatos, H. C.; Walukiewicz, W.; Siejka, J.
1981-01-01
Spectral and transient responses of photostimulated current in MOS structures were employed for the study of GaAs-anodic oxide interface states. Discrete deep traps at 0.7 and 0.85 eV below the conduction band were found with concentrations of 5 x 10 to the 12th/sq cm and 7 x 10 to the 11th/sq cm, respectively. These traps coincide with interface states induced on clean GaAs surfaces by oxygen and/or metal adatoms (submonolayer coverage). In contrast to surfaces with low oxygen coverage, the GaAs-thick oxide interfaces exhibited a high density (about 10 to the 14th/sq cm) of shallow donors and acceptors. Photoexcitation of these donor-acceptor pairs led to a gigantic photoionization of deep interface states with rates 1000 times greater than direct transitions into the conduction band. The gigantic photoionization is explained on the basis of energy transfer from excited donor-acceptor pairs to deep states.
Influence of growth conditions on subsequent submonolayer oxide decomposition on Si(111)
NASA Astrophysics Data System (ADS)
Shklyaev, A. A.; Aono, Masakazu; Suzuki, Takanori
1996-10-01
The decomposition kinetics of oxide with a coverage between 0.1 and 0.5 ML, grown by oxidation of the Si(111)-7×7 surface at temperatures between 550 and 800 °C for oxygen pressures (Pox) between 3×10-8 and 2×10-6 Torr, is investigated with optical second-harmonic generation. Through the analysis of the pressure dependence of the initial oxide-growth rate, we separate the conditions for a slow oxide growth at Pox near Ptr(T) and for a rapid oxide growth at Pox>3Ptr(T), where Ptr(T) is the transition pressure to Si-etching regime without oxide growth. For the rapidly grown oxide, the oxide decomposition rate decreases with increasing oxide coverage, whereas the activation energy of about 3 eV does not change significantly. While in the case when the oxide is desorbed at the same temperature as are used for oxide growth, the oxide decomposition is described by an apparent activation energy of 1.5 eV. For the slowly grown oxide of 0.1 ML coverage, the oxide desorption kinetics shows a rapid decomposition stage followed by a slow stage. For the slowly grown oxide of 0.3 ML coverage, the slow stage with a large activation energy of 4.1 eV becomes dominant in the latter part of decomposition. The dependence of the desorption kinetics on the oxide-growth conditions described here could be a reason for the scattering of the kinetic parameters in the literature for O2 interaction with silicon at elevated temperatures.
Automated discovery and construction of surface phase diagrams using machine learning
Ulissi, Zachary W.; Singh, Aayush R.; Tsai, Charlie; ...
2016-08-24
Surface phase diagrams are necessary for understanding surface chemistry in electrochemical catalysis, where a range of adsorbates and coverages exist at varying applied potentials. These diagrams are typically constructed using intuition, which risks missing complex coverages and configurations at potentials of interest. More accurate cluster expansion methods are often difficult to implement quickly for new surfaces. We adopt a machine learning approach to rectify both issues. Using a Gaussian process regression model, the free energy of all possible adsorbate coverages for surfaces is predicted for a finite number of adsorption sites. Our result demonstrates a rational, simple, and systematic approachmore » for generating accurate free-energy diagrams with reduced computational resources. Finally, the Pourbaix diagram for the IrO 2(110) surface (with nine coverages from fully hydrogenated to fully oxygenated surfaces) is reconstructed using just 20 electronic structure relaxations, compared to approximately 90 using typical search methods. Similar efficiency is demonstrated for the MoS 2 surface.« less
Foley, Brian M; Hernández, Sandra C; Duda, John C; Robinson, Jeremy T; Walton, Scott G; Hopkins, Patrick E
2015-08-12
The high mobility exhibited by both supported and suspended graphene, as well as its large in-plane thermal conductivity, has generated much excitement across a variety of applications. As exciting as these properties are, one of the principal issues inhibiting the development of graphene technologies pertains to difficulties in engineering high-quality metal contacts on graphene. As device dimensions decrease, the thermal and electrical resistance at the metal/graphene interface plays a dominant role in degrading overall performance. Here we demonstrate the use of a low energy, electron-beam plasma to functionalize graphene with oxygen, fluorine, and nitrogen groups, as a method to tune the thermal and electrical transport properties across gold-single layer graphene (Au/SLG) interfaces. We find that while oxygen and nitrogen groups improve the thermal boundary conductance (hK) at the interface, their presence impairs electrical transport leading to increased contact resistance (ρC). Conversely, functionalization with fluorine has no impact on hK, yet ρC decreases with increasing coverage densities. These findings indicate exciting possibilities using plasma-based chemical functionalization to tailor the thermal and electrical transport properties of metal/2D material contacts.
Alteration of Developmental and Pathological Retinal Angiogenesis in angptl4-deficient Mice*
Perdiguero, Elisa Gomez; Galaup, Ariane; Durand, Mélanie; Teillon, Jérémie; Philippe, Josette; Valenzuela, David M.; Murphy, Andrew J.; Yancopoulos, George D.; Thurston, Gavin; Germain, Stéphane
2011-01-01
Proper vessel maturation, remodeling of endothelial junctions, and recruitment of perivascular cells is crucial for establishing and maintaining vessel functions. In proliferative retinopathies, hypoxia-induced angiogenesis is associated with disruption of the vascular barrier, edema, and vision loss. Therefore, identifying factors that regulate vascular maturation is critical to target pathological angiogenesis. Given the conflicting role of angiopoietin-like-4 (ANGPTL4) reported in the current literature using gain of function systems both in vitro and in vivo, the goal of this study was to characterize angiogenesis, focusing on perinatal retinal vascularization and pathological circumstances in angpl4-deficient mice. We report altered organization of endothelial junctions and pericyte coverage, both leading to impaired angiogenesis and increased vascular leakage that were eventually caught up, suggesting a delay in vessel maturation. In a model of oxygen-induced retinopathy, pathological neovascularization, which results from tissue hypoxia, was also strongly inhibited in angptl4-deficient mice. This study therefore shows that ANGPTL4 tunes endothelial cell junction organization and pericyte coverage and controls vascular permeability and angiogenesis, both during development and in pathological conditions. PMID:21832056
Analysis of cloud top height and cloud coverage from satellites using the O2 A and B bands
NASA Technical Reports Server (NTRS)
Kuze, Akihiko; Chance, Kelly V.
1994-01-01
Cloud height and cloud coverage detection are important for total ozone retrieval using ultraviolet and visible scattered light. Use of the O2 A and B bands, around 761 and 687 nm, by a satellite-borne instrument of moderately high spectral resolution viewing in the nadir makes it possible to detect cloud top height and related parameters, including fractional coverage. The measured values of a satellite-borne spectrometer are convolutions of the instrument slit function and the atmospheric transmittance between cloud top and satellite. Studies here determine the optical depth between a satellite orbit and the Earth or cloud top height to high accuracy using FASCODE 3. Cloud top height and a cloud coverage parameter are determined by least squares fitting to calculated radiance ratios in the oxygen bands. A grid search method is used to search the parameter space of cloud top height and the coverage parameter to minimize an appropriate sum of squares of deviations. For this search, nonlinearity of the atmospheric transmittance (i.e., leverage based on varying amounts of saturation in the absorption spectrum) is important for distinguishing between cloud top height and fractional coverage. Using the above-mentioned method, an operational cloud detection algorithm which uses minimal computation time can be implemented.
NASA Astrophysics Data System (ADS)
Navas, Javier; Araujo, Daniel; Piñero, José Carlos; Sánchez-Coronilla, Antonio; Blanco, Eduardo; Villar, Pilar; Alcántara, Rodrigo; Montserrat, Josep; Florentin, Matthieu; Eon, David; Pernot, Julien
2018-03-01
Phenomena related with the diamond surface of both power electronic and biosensor devices govern their global behaviour. In particular H- or O-terminations lead to wide variations in their characteristics. To study the origins of such aspects in greater depth, different methods to achieve oxygen terminated diamond were investigated following a multi-technique approach. DFT calculations were then performed to understand the different configurations between the C and O atoms. Three methods for O-terminating the diamond surface were performed: two physical methods with ozone at different pressures, and an acid chemical treatment. X-ray photoelectron spectroscopy, spectroscopic ellipsometry, HRTEM, and EELS were used to characterize the oxygenated surface. Periodic-DFT calculations were undertaken to understand the effect of the different ways in which the oxygen atoms are bonded to carbon atoms on the diamond surface. XPS results showed the presence of hydroxyl or ether groups, composed of simple Csbnd O bonds, and the acid treatment resulted in the highest amount of O on the diamond surface. In turn, ellipsometry showed that the different treatments led to the surface having different optical properties, such as a greater refraction index and extinction coefficient in the case of the sample subjected to acid treatment. TEM analysis showed that applying temperature treatment improved the distribution of the oxygen atoms at the interface and that this generates a thinner amount of oxygen at each position and higher interfacial coverage. Finally, DFT calculations showed both an increase in the number of preferential electron transport pathways when π bonds and ether groups appear in the system, and also the presence of states in the middle of the band gap when there are π bonds, Cdbnd C or Cdbnd O.
Systematic review of the incremental costs of interventions that increase immunization coverage.
Ozawa, Sachiko; Yemeke, Tatenda T; Thompson, Kimberly M
2018-05-10
Achieving and maintaining high vaccination coverage requires investments, but the costs and effectiveness of interventions to increase coverage remain poorly characterized. We conducted a systematic review of the literature to identify peer-reviewed studies published in English that reported interventions aimed at increasing immunization coverage and the associated costs and effectiveness of the interventions. We found limited information in the literature, with many studies reporting effectiveness estimates, but not providing cost information. Using the available data, we developed a cost function to support future programmatic decisions about investments in interventions to increase immunization coverage for relatively low and high-income countries. The cost function estimates the non-vaccine cost per dose of interventions to increase absolute immunization coverage by one percent, through either campaigns or routine immunization. The cost per dose per percent increase in absolute coverage increased with higher baseline coverage, demonstrating increasing incremental costs required to reach higher coverage levels. Future studies should evaluate the performance of the cost function and add to the database of available evidence to better characterize heterogeneity in costs and generalizability of the cost function. Copyright © 2018. Published by Elsevier Ltd.
Influenza vaccination coverage among US children from 2004/2005 to 2015/2016.
Tian, Changwei; Wang, Hua; Wang, Wenming; Luo, Xiaoming
2018-05-15
Quantify the influenza vaccine coverage is essential to identify emerging concerns and to immunization programs for targeting interventions. Data from National Health Interview Survey were used to estimate receipt of at least one dose of influenza vaccination among children 6 months to 17 years of age. Influenza vaccination coverage increased from 16.70% during 2004/2005 to 49.43% during 2015/2016 (3.18% per year, P < 0.001); however, the coverage increased slightly after 2010/2011. Children at high risk of influenza complications had higher influenza vaccination coverage than non at-risk children. Boys and girls had similar coverage each year. While the coverage increased from 2004/2005 to 2015/2016 for all age groups, the coverage decreased with age each year (-0.64 to -1.58% per age group). There was a higher and rapid increase of coverage in Northeast than Midwest, South and West. American Indian or Alaskan Native and Asian showed higher coverage than other race groups (White, Black/African American, Multiple race). Multivariable analysis showed that high-risk status and region had the greatest associations with levels of vaccine coverage. Although the influenza vaccination coverage among children had increased remarkably since 2004/2005, establishing more effective immunization programs are warranted to achieve the Healthy People 2020 target.
Vibrational Studies of Adsorbate-Induced Reconstruction on Molybdenum Surfaces.
NASA Astrophysics Data System (ADS)
Lopinski, Gregory Peter
Adsorbate-induced rearrangement of the substrate structure strongly modifies the adsorbate-substrate and adsorbate-adsorbate interactions, leading to the complex behavior observed in many chemisorption systems. In this thesis the H/Mo(211), O/Mo(211) and Na/Mo(100) systems have been studied using high resolution electron energy loss spectroscopy (HREELS) to observe vibrations of the adsorbed atoms. The vibrational data is correlated with observations of the long-range order probed by LEED as well as the work function changes induced by adsorption. Adsorbate -induced substrate reconstruction plays an important role in all three of these systems. Studies of the coadsorption systems O+H/Mo(211) and Na+O/Mo(100) indicate how these effects can influence interactions between adsorbates. For H/Mo(211), above 1ML a (1 x 1) to (1 x 2) transition is observed and attributed to modification of the substrate periodicity. Below 1ML, H atoms are bridge bonded and induce local distortions of the substrate. The transition to the (1 x 2) phase involves the ordering of these displacements and occupation of three-fold sites partially populated by conversion of the bridge bonded species. This conversion accounts for the sawtooth-like coverage dependence of the work function. The structural model proposed for this system is also supported by the desorption parameters and partial molar entropy extracted from adsorption isobars. Oxygen adsorption on Mo(211) involves the occupation of multiple binding sites, with both the long-range order and the local geometry of the adsorbate phases strongly temperature dependent. Coadsorption of low coverages of oxygen and hydrogen leads to segregation of the two adsorbates which can be understood in terms of a substrate-mediated repulsive interaction between O and H. For Na/Mo(100), the frequency of the Na-Mo symmetric stretch mode does not shift with coverage although the mode intensity is strongly coverage dependent. The absence of a frequency shift as well as the form of the observed coverage dependence differ from the predictions of the traditional charge transfer model of alkali adsorption. The relevance of the vibrational results to the Na-induced structural changes observed on this surface are also discussed. Na adsorption has been found to dramatically alter the interaction of oxygen with this surface, due to the presence of a strong attractive interaction between Na and O that forces O atoms to occupy a different binding site than on a clean surface.
An Assessment of SeaWiFS and MODIS Ocean Coverage
NASA Technical Reports Server (NTRS)
Woodward, Robert H.; Gregg, Watson W.
1998-01-01
Ocean coverages of SeaWiFS and MODIS were assessed for three seasons by considering monthly mean values of surface winds speeds and cloud cover. Mean and maximum coverages combined SeaWiFS and MODIS by considering combined coverages for ten-degree increments of the MODIS orbital mean anomaly. From this analysis the mean and maximum combined coverages for SeaWiFS and MODIS were determined for one and four-day periods for spring, summer, and winter seasons. Loss of coverage due to Sun glint and cloud cover were identified for both the individual and combined cases. Our analyses indicate that MODIS will enhance ocean coverage for all three seasons examined. ne combined SeaWiFS/MODIS show an increase of coverage of 42.2% to 48.7% over SeaWiFS alone for the three seasons studied; the increase in maximum one day coverage ranges from 47.5% to 52.0%. The increase in four-day coverage for the combined case ranged from 31.0% to 35.8% for mean coverage and 33.1 % to 39.2% for maximum coverage. We computed meridional distributions of coverages by binning the data into five-degree latitude bands. Our analysis shows a strong seasonal dependence of coverage. In general the meridional analysis indicates that increase in coverages for SeaWiFS/MODIS over SeaWiFS alone are greatest near the solar declination.
Fung, K; Beck, J R; Lopez, H C; Mongero, L B
2013-11-01
Clinician rounding on bedside extracorporeal membrane oxygenation (ECMO) is a common coverage practice at many centers across the USA. Occasionally, clinical issues or concerns may go unnoticed for a considerable period of time during the intervals of clinician rounds. We report a case utilizing the LiveVue (Spectrum Medical, Fort Mill, SC) remote monitoring for care of a patient on ECMO. A patient was placed on veno-arterial (VA) ECMO in our intensive care unit, using a Rotaflow centrifugal pump and a Quadrox D polymethylpentene (PMP) fiber oxygenator (both Maquet, Fairfield, NJ). Following ECMO initiation and stabilization, a two-hour rounding schedule was established for the covering perfusionist. On day two, shortly after the perfusionist had rounded, the ECMO flow began fluctuating between 0.1 and 2.1 L/min. A compliance alert (i.e. red flashing notification) was recognized by the perfusion team on a large screen monitor installed in the perfusion pump room. Immediate response from the perfusion team identified venous inflow obstruction due to cannula malposition. The pump revolutions per minute (rpm) and, thus, the resulting flow were temporarily reduced to prevent vessel intimal damage and the surgical team was summoned to reposition the venous cannula. Later in that ECMO run, a steady rise in pre-oxygenator pressure was noted by the perfusionist. This increasingly concerning event was able to be trended and monitored with the LiveVue from a remote location. After a few hours, a compliance alert was noticed again on the LiveVue screen in the pump room. The pre-oxygenator pressure increased by 150 mmHg and the circuit flow decreased by half. Again, the perfusionist response was immediate and an oxygenator change-out ensued. Once more, a potentially dangerous clinical scenario was avoided with continuous critical parameter remote monitoring using the LiveVue system.
Cathalot, Cecile; Rabouille, Christophe; Sauter, Eberhard; Schewe, Ingo; Soltwedel, Thomas
2015-01-01
The past decades have seen remarkable changes in the Arctic, a hotspot for climate change. Nevertheless, impacts of such changes on the biogeochemical cycles and Arctic marine ecosystems are still largely unknown. During cruises to the deep-sea observatory HAUSGARTEN in July 2007 and 2008, we investigated the biogeochemical recycling of organic matter in Arctic margin sediments by performing shipboard measurements of oxygen profiles, bacterial activities and biogenic sediment compounds (pigment, protein, organic carbon, and phospholipid contents). Additional in situ oxygen profiles were performed at two sites. This study aims at characterizing benthic mineralization activity along local bathymetric and latitudinal transects. The spatial coverage of this study is unique since it focuses on the transition from shelf to Deep Ocean, and from close to the ice edge to more open waters. Biogeochemical recycling across the continental margin showed a classical bathymetric pattern with overall low fluxes except for the deepest station located in the Molloy Hole (5500 m), a seafloor depression acting as an organic matter depot center. A gradient in benthic mineralization rates arises along the latitudinal transect with clearly higher values at the southern stations (average diffusive oxygen uptake of 0.49 ± 0.18 mmol O2 m-2 d-1) compared to the northern sites (0.22 ± 0.09 mmol O2 m-2 d-1). The benthic mineralization activity at the HAUSGARTEN observatory thus increases southward and appears to reflect the amount of organic matter reaching the seafloor rather than its lability. Although organic matter content and potential bacterial activity clearly follow this gradient, sediment pigments and phospholipids exhibit no increase with latitude whereas satellite images of surface ocean chlorophyll a indicate local seasonal patterns of primary production. Our results suggest that predicted increases in primary production in the Arctic Ocean could induce a larger export of more refractory organic matter due to the longer production season and the extension of the ice-free zone. PMID:26465885
Eren, Baran; Kersell, Heath; Weatherup, Robert S; Heine, Christian; Crumlin, Ethan J; Friend, Cynthia M; Salmeron, Miquel B
2018-01-18
Using ambient pressure X-ray photoelectron spectroscopy (APXPS) and high pressure scanning tunneling microscopy (HPSTM), we show that in equilibrium with 0.01-0.2 Torr of methanol vapor, at room temperature, the Cu(100) surface is covered with methoxy species forming a c(2 × 2) overlayer structure. In contrast, no methoxy is formed if the surface is saturated with an ordered oxygen layer, even when the methanol pressure is 0.2 Torr. At oxygen coverages below saturation, methanol dissociates and reacts with the atomic oxygen, producing methoxy and formate on the surface, and formaldehyde that desorbs to the gas phase. Unlike the case of pure carbon monoxide and carbon dioxide, methanol does not induce the restructuring of the Cu(100) surface. These results provide insight into catalytic anhydrous production of aldehydes.
NASA Technical Reports Server (NTRS)
Schmidt, A. F. (Editor)
1972-01-01
Selected information is presented from an assemblage of reports and publications on heat transfer and fluid dynamics with direct applicability to oxygen systems. For each document cited, an abstract has been prepared together with key words and a listing of most important references found in the document. Additionally, an author index, a subject index, and a key word index have been provided to simplify the retrieval of specific information from this work. In each subject area - e.g., boiling heat transfer - the individual citations are listed alphabetically by first author, with review papers dually noted under the appropriate subject category and under review papers. Of the documents reviewed and evaluated for inclusion in this publication, coverage of existing information directly concerned with oxygen was given primary emphasis. However, work not specifically oxygen-designated but considered applicable to oxygen by the reviewer e.g., a two-phase friction factor correlation derived from nitrogen experiments is occasionally given where no actual oxygen data exist, as an aid to the reader. Approximately 130 abstracts are listed.
Acetone and Water on TiO₂(110): H/D Exchange
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henderson, Michael A.
2005-04-12
Isotopic H/D exchange between coadsorbed acetone and water on the TiO?(110) surface was examined using temperature programmed desorption (TPD) as a function of coverage and two surface pretreatments (oxidation and reduction). Coadsorbed acetone and water interact repulsively on reduced TiO?(110) based on results from the companion paper to this study, with water exerting a greater influence in destabilizing acetone and acetone having only a nominal influence on water. Despite the repulsive interaction between these coadsorbates, about 0.02 ML of a 1 ML d6-acetone on the reduced surface exhibits H/D exchange with coadsorbed water, with the exchange occurring exclusively in themore » high temperature region of the d?-acetone TPD spectrum at {approx}340 K. The effect was confirmed with combinations of d?-acetone and D?O. The extent of exchange decreased on the reduced surface with water coverages above {approx}0.3 ML due to the ability of water to displace coadsorbed acetone from first layer sites to the multilayer. In contrast, the extent of exchange increased by a factor of 3 when the surface was pre-oxidized prior to coadsorption. In this case, there was no evidence for the negative influence of high water coverages on the extent of H/D exchange. Comparison of the TPD spectra from the exchange products (either d?- or d?-acetone depending on the coadsorption pairing) suggests that, in addition to the 340 K exchange process seen on the reduced surface, a second exchange process was observed on the oxidized surface at {approx}390 K. In both cases (oxidized and reduced), desorption of the H/D exchange products appeared to be reaction limited and to involve the influence of OH/OD groups (or water formed during recombinative desorption of OH/OD groups) instead of molecularly adsorbed water. The 340 K exchange process is assigned to reaction at step sites and the 390 K exchange process is attributed to the influence of oxygen adatoms deposited during surface oxidation. The H/D exchange mechanism likely involves an enolate or propenol surface intermediate formed transiently during the desorption of oxygen-stabilized acetone molecules.« less
Employee responses to health insurance premium increases.
Goldman, Dana P; Leibowitz, Arleen A; Robalino, David A
2004-01-01
To determine the sensitivity of employees' health insurance decisions--including the decision to not choose health maintenance organization or fee-for-service coverage--during periods of rapidly escalating healthcare costs. A retrospective cohort study of employee plan choices at a single large firm with a "cafeteria-style" benefits plan wherein employees paid all the additional cost of purchasing more generous insurance. We modeled the probability that an employee would drop coverage or switch plans in response to employee premium increases using data from a single large US company with employees across 47 states during the 3-year period of 1989 through 1991, a time of large premium increases within and across plans. Premium increases induced substantial plan switching. Single employees were more likely to respond to premium increases by dropping coverage, whereas families tended to switch to another plan. Premium increases of 10% induced 7% of single employees to drop or severely cut back on coverage; 13% to switch to another plan; and 80% to remain in their existing plan. Similar figures for those with family coverage were 11%, 12%, and 77%, respectively. Simulation results that control for known covariates show similar increases. When faced with a dramatic increase in premiums--on the order of 20%--nearly one fifth of the single employees dropped coverage compared with 10% of those with family coverage. Employee coverage decisions are sensitive to rapidly increasing premiums, and single employees may be likely to drop coverage. This finding suggests that sustained premium increases could induce substantial increases in the number of uninsured individuals.
Bardenheier, Barbara H; Shefer, Abigail; McKibben, Linda; Roberts, Henry; Rhew, David; Bratzler, Dale
2005-01-01
Between 1999 and 2002, a multistate demonstration project was conducted in long-term care facilities (LTCFs) to encourage implementation of standing orders programs (SOP) as evidence-based vaccine delivery strategies to increase influenza and pneumococcal vaccination coverage in LTCFs. Examine predictors of increase in influenza and pneumococcal vaccination coverage in LTCFs. Intervention study. Self-administered surveys of LTCFs merged with data from OSCAR (On-line Survey Certification and Reporting System) and immunization coverage was abstracted from residents' medical charts in LTCFs. Twenty LTCFs were sampled from 9 intervention and 5 control states in the 2000 to 2001 influenza season for baseline and during the 2001 to 2002 influenza season for postintervention. Each state's quality improvement organization (QIO) promoted the use of standing orders for immunizations as well as other strategies to increase immunization coverage among LTCF residents. Multivariate analysis included Poisson regression to determine independent predictors of at least a 10 percentage-point increase in facility influenza and pneumococcal vaccination coverage. Forty-two (20%) and 59 (28%) of the facilities had at least a 10 percentage-point increase in influenza and pneumococcal immunizations, respectively. In the multivariate analysis, predictors associated with increase in influenza vaccination coverage included adoption of requirement in written immunization protocol to document refusals, less-demanding consent requirements, lower baseline influenza coverage, and small facility size. Factors associated with increase in pneumococcal vaccination coverage included adoption of recording pneumococcal immunizations in a consistent place, affiliation with a multifacility chain, and provision of resource materials. To improve the health of LTCF residents, strategies should be considered that increase immunization coverage, including written protocol for immunizations and documentation of refusals, documenting vaccination status in a consistent place in medical records, and minimal consent requirements for vaccinations.
Interactions of Oxygen and Hydrogen on Pd(111) surface
DOE Office of Scientific and Technical Information (OSTI.GOV)
Demchenko, D.O.; Sacha, G.M.; Salmeron, M.
2008-06-25
The coadsorption and interactions of oxygen and hydrogen on Pd(1 1 1) was studied by scanning tunneling microscopy and density functional theory calculations. In the absence of hydrogen oxygen forms a (2 x 2) ordered structure. Coadsorption of hydrogen leads to a structural transformation from (2 x 2) to a ({radical}3 x {radical}3)R30 degree structure. In addition to this transformation, hydrogen enhances the mobility of oxygen. To explain these observations, the interaction of oxygen and hydrogen on Pd(1 1 1) was studied within the density functional theory. In agreement with the experiment the calculations find a total energy minimum formore » the oxygen (2 x 2) structure. The interaction between H and O atoms was found to be repulsive and short ranged, leading to a compression of the O islands from (2 x 2) to ({radical}3 x {radical}3)R30 degree ordered structure at high H coverage. The computed energy barriers for the oxygen diffusion were found to be reduced due to the coadsorption of hydrogen, in agreement with the experimentally observed enhancement of oxygen mobility. The calculations also support the finding that at low temperatures the water formation reaction does not occur on Pd(1 1 1).« less
Affordable Care Act Impact on Medicaid Coverage of Smoking-Cessation Treatments.
McMenamin, Sara B; Yoeun, Sara W; Halpin, Helen A
2018-04-01
Four sections of the Affordable Care Act address the expansion of Medicaid coverage for recommended smoking-cessation treatments for: (1) pregnant women (Section 4107), (2) all enrollees through a financial incentive (1% Federal Medical Assistance Percentage increase) to offer comprehensive coverage (Section 4106), (3) all enrollees through Medicaid formulary requirements (Section 2502), and (4) Medicaid expansion enrollees (Section 2001). The purpose of this study is to document changes in Medicaid coverage for smoking-cessation treatments since the passage of the Affordable Care Act and to assess how implementation has differentially affected Medicaid coverage policies for: pregnant women, enrollees in traditional Medicaid, and Medicaid expansion enrollees. From January through June 2017, data were collected and analyzed from 51 Medicaid programs (50 states plus the District of Columbia) through a web-based survey and review of benefits documents to assess coverage policies for smoking-cessation treatments. Forty-seven Medicaid programs have increased coverage for smoking-cessation treatments post-implementation of the Affordable Care Act by adopting one or more of the four smoking-cessation treatment provisions. Coverage for pregnant women increased in 37 states, coverage for newly eligible expansion enrollees increased in 32 states, and 15 states added coverage and/or removed copayments in order to apply for a 1% increase in the Federal Medical Assistance Percentage. Coverage for all recommended pharmacotherapy and group and individual counseling increased from seven states in 2009 to 28 states in 2017. The Affordable Care Act was successful in improving and expanding state Medicaid coverage of effective smoking-cessation treatments. Many programs are not fully compliant with the law, and additional guidance and clarification from the Centers for Medicare and Medicaid Services may be needed. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Insurance premiums and insurance coverage of near-poor children.
Hadley, Jack; Reschovsky, James D; Cunningham, Peter; Kenney, Genevieve; Dubay, Lisa
States increasingly are using premiums for near-poor children in their public insurance programs (Medicaid/SCHIP) to limit private insurance crowd-out and constrain program costs. Using national data from four rounds of the Community Tracking Study Household Surveys spanning the seven years from 1996 to 2003, this study estimates a multinomial logistic regression model examining how public and private insurance premiums affect insurance coverage outcomes (Medicaid/SCHIP coverage, private coverage, and no coverage). Higher public premiums are significantly associated with a lower probability of public coverage and higher probabilities of private coverage and uninsurance; higher private premiums are significantly related to a lower probability of private coverage and higher probabilities of public coverage and uninsurance. The results imply that uninsurance rates will rise if both public and private premiums increase, and suggest that states that impose or increase public insurance premiums for near-poor children will succeed in discouraging crowd-out of private insurance, but at the expense of higher rates of uninsurance. Sustained increases in private insurance premiums will continue to create enrollment pressures on state insurance programs for children.
Delatolla, R; Séguin, C; Springthorpe, S; Gorman, E; Campbell, A; Douglas, I
2015-10-01
The goal of this study was to investigate the potential of biofiltration to reduce the formation potential of disinfection byproducts (DBPs). Particularly, the work investigates the effect of the duration of the filter cycle on the formation potential of total trihalomethanes (TTHM) and five species of haloacetic acids (HAA5), dissolved oxygen (DO), organic carbon, nitrogen and total phosphorous concentrations along with biofilm coverage of the filter media and biomass viability of the attached cells. The study was conducted on a full-scale biologically active filter, with anthracite and sand media, at the Britannia water treatment plant (WTP), located in Ottawa, Ontario, Canada. The formation potential of both TTHMs and HAA5s decreased due to biofiltration. However the lowest formation potentials for both groups of DBPs and or their precursors were observed immediately following a backwash event. Hence, the highest percent removal of DBPs was observed during the early stages of the biofiltration cycle, which suggests that a higher frequency of backwashing will reduce the formation of DBPs. Variable pressure scanning electron microscopy (VPSEM) analysis shows that biofilm coverage of anthracite and sand media increases as the filtration cycle progressed, while biomass viability analysis demonstrates that the percentage of cells attached to the anthracite and sand media also increases as the filtration cycle progresses. These results suggest that the development and growth of biofilm on the filters increases the DPB formation potential. Copyright © 2015 Elsevier Ltd. All rights reserved.
Quantum tunneling of oxygen atoms on very cold surfaces.
Minissale, M; Congiu, E; Baouche, S; Chaabouni, H; Moudens, A; Dulieu, F; Accolla, M; Cazaux, S; Manicó, G; Pirronello, V
2013-08-02
Any evolving system can change state via thermal mechanisms (hopping a barrier) or via quantum tunneling. Most of the time, efficient classical mechanisms dominate at high temperatures. This is why an increase of the temperature can initiate the chemistry. We present here an experimental investigation of O-atom diffusion and reactivity on water ice. We explore the 6-25 K temperature range at submonolayer surface coverages. We derive the diffusion temperature law and observe the transition from quantum to classical diffusion. Despite the high mass of O, quantum tunneling is efficient even at 6 K. As a consequence, the solid-state astrochemistry of cold regions should be reconsidered and should include the possibility of forming larger organic molecules than previously expected.
Spawning activity of the Australian lungfish Neoceratodus forsteri in an impoundment.
Roberts, D T; Mallett, S; Krück, N C; Loh, W; Tibbetts, I
2014-01-01
This study assessed the spawning activity of the threatened Australian lungfish Neoceratodus forsteri by measuring egg densities within the artificial habitat of a large impoundment (Lake Wivenhoe, Australia). Eggs were sampled (August to November 2009) from multiple locations across the impoundment, but occurred at highest densities in water shallower than 40 cm along shorelines with a dense cover of submerged terrestrial vegetation. The numbers of eggs declined over the study period and all samples were dominated by early developmental stages and high proportions of unviable eggs. The quality of the littoral spawning habitats declined over the study as flooded terrestrial grasses decomposed and filamentous algae coverage increased. Water temperatures at the spawning site exhibited extreme variations, ranging over 20·4° C in water shallower than 5 cm. Dissolved oxygen concentrations regularly declined to <1 mg l⁻¹ at 40 and 80 cm water depth. Spawning habitats utilised by N. forsteri within impoundments expose embryos to increased risk of desiccation or excessive submergence through water-level variations, and extremes in temperature and dissolved oxygen concentration that present numerous challenges for successful spawning and recruitment of N. forsteri in large impoundment environments. © 2014 The Fisheries Society of the British Isles.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-20
...; b. expanding coverage of oxygenated fuels to include counties where a strong commuting pattern into... gas and electric vehicles; and, d. employee commute options programs. NC DENR committed to implement... received by March 25, 2013, the rule would be withdrawn and not take effect, but that the proposed rule...
Ishikawa, Atsushi; Nakatsuji, Hiroshi
2013-08-05
O1s core-electron binding energies (CEBE) of the atomic oxygens on different Ag surfaces were investigated by the symmetry adapted cluster-configuration interaction (SAC-CI) method combined with the dipped adcluster model, in which the electron exchange between bulk metal and adsorbate is taken into account properly. Electrophilic and nucleophilic oxygens (O(elec) and O(nuc)) that might be important for olefin epoxidation in a low-oxygen coverage condition were focused here. We consider the O1s CEBE as a key property to distinguish the surface oxygen states, and series of calculation was carried out by the Hartree-Fock, Density functional theory, and SAC/SAC-CI methods. The experimental information and our SAC/SAC-CI results indicate that O(elec) is the atomic oxygen adsorbed on the fcc site of Ag(111) and that O(nuc) is the one on the reconstructed added-row site of Ag(110) and that one- and two-electron transfers occur, respectively, to the O(elec) and O(nuc) adclusters from the silver surface. Copyright © 2013 Wiley Periodicals, Inc.
Twelve-year trends in health insurance coverage among Latinos, by subgroup and immigration status.
Shah, N Sarita; Carrasquillo, Olveen
2006-01-01
We examine twelve-year trends in the Latino uninsured population by ethnic subgroup and immigration status. From 1993 to 1999, most Latino subgroups, particularly Puerto Ricans, had large decreases in Medicaid coverage. For some subgroups these were offset by increases in employer coverage, but not for Mexicans, resulting in a four-percentage-point increase in their uninsured population. During 2000-2004, Medicaid/SCHIP expansions benefited most subgroups and mitigated smaller losses in employer coverage. However, during 1993-2004, the percentage of noncitizen Latinos lacking coverage increased by several percentage points. This was attributable to Medicaid losses during 1993-1999 and losses in employer coverage during 2000-2004.
Lipton, Brandy J; Decker, Sandra L; Sommers, Benjamin D
2017-04-01
Prior to the Affordable Care Act, one in three young adults aged 19 to 25 years were uninsured, with substantial racial/ethnic disparities in coverage. We analyzed the separate and cumulative changes in racial/ethnic disparities in coverage and access to care among young adults after implementation of the Affordable Care Act's 2010 dependent coverage provision and 2014 Medicaid and Marketplace expansions. We find that the dependent coverage provision was associated with similar gains across racial/ethnic groups, but the 2014 expansion was associated with larger gains in coverage among Hispanics and Blacks relative to Whites. After the 2014 expansion, coverage increased by 11.0 and 10.1 percentage points among Hispanics and Blacks, respectively, compared with a 5.6 percentage point increase among Whites. The percentage with a usual source of care and a recent doctor's visit also increased more for Blacks relative to Whites. Increases in coverage were larger in Medicaid expansion compared with nonexpansion states for most racial/ethnic groups.
Acetone Chemistry on Oxidized and Reduced TiO 2(110)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henderson, Michael A
2004-12-09
The chemistry of acetone on the oxidized and reduced surfaces of TiO 2(110) was examined using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The reduced surface was prepared with about 7% oxygen vacancy sites by annealing in ultrahigh vacuum (UHV) at 850 K, and the oxidized surface was prepared by exposure of the reduced surface to molecular oxygen at 95 K followed by heating the surface to a variety of temperatures between 200 and 500 K. Acetone adsorbs molecularly on the reduced surface with no evidence for either decomposition or preferential binding at vacancy sites.more » Based on HREELS, the majority of acetone molecules adsorbed in an η¹ configuration at Ti⁴⁺ sites through interaction of lone pair electrons on the carbonyl oxygen atom. Repulsive acetone-acetone interactions shift the desorption peak from 345 K at low coverage to 175 K as the first layer saturates with a coverage of ~ 1 ML. In contrast, about 7% of the acetone adlayer decomposes when the surface is pretreated with molecular oxygen. Acetate is among the detected decomposition products, but only comprises about 1/3rd of the amount of acetone decomposed and its yield depends on the temperature at which the O₂ exposed surface was preheated to prior to acetone adsorption. Aside from the small level of irreversible decomposition, about 0.25 ML of acetone is stabilized to 375 K by coadsorbed oxygen. These acetone species exhibit an HREELS spectrum unlike that of η¹-acetone or of any other species proposed to exist from the interaction of acetone with TiO₂ powders. Based on the presence of extensive ¹⁶O/¹⁸O exchange between acetone and coadsorbed oxygen in the 375 K acetone TPD state, it is proposed that a polymeric form of acetone forms on the TiO₂(110) surface through nucleophilic attack of oxygen on the carbonyl carbon atom of acetone, and is propagated to neighboring η¹-acetone molecules. This process is initiated at temperatures as low as 135 K based on HREELS. Although the dominant thermal pathway of this surface species is to liberate acetone in UHV, it may be a key intermediate in acetone thermal and photolytic chemistry on TiO₂ surfaces.« less
Nitrogen-to-oxygen as a tracer of the chemical evolution of the Local and young Universe
NASA Astrophysics Data System (ADS)
Pérez-Montero, E.
2013-05-01
Oxygen optical emission-lines are used exhaustively as tracers of the metal content in gaseous nebulae ionized during different episodes of massive star formation. The high luminosity of these lines make them to be detected from the Local Universe up to starbursts at high redshift. Occasionally, in those cases where these lines cannot be measured due to the spectral coverage or to the redshift, nitrogen emission-lines are used instead. However, both nitrogen and oxygen have different nucleosynthetic origins, so the study of chemical abundances from nitrogen emission-lines introduces variables depending on the star formation history of each galaxy that must be taken into account. This contribution summarizes those risks involved in using metallicity tracers based on optical nitrogen emission lines and also describes the advantages of using instead the nitrogen-to-oxygen ratio as a tracer itself, based mainly on its independence on star formation rate, avoiding selection effects at high redshift.
Cunningham, Peter; Sheng, Yaou
2018-06-01
Expansions of health insurance coverage tend to increase hospital emergency department (ED) utilization and inpatient admissions. However, provisions in the Affordable Care Act that expanded primary care supply were intended in part to offset the potential for increased hospital utilization. To examine the association between health insurance coverage, primary care supply, and ED and inpatient utilization, and to assess how both factors contributed to trends in utilization in California between 2012 and 2015. Population-based measures of ED and inpatient utilization, insurance coverage, and primary care supply were constructed for California counties for the years 2012 through 2015. Fixed effects regression analysis is used to examine the association between health insurance coverage, primary care supply, and rates of preventable ED and inpatient utilization. Higher levels of Medicaid coverage in a county are associated with higher levels of preventable ED and inpatient utilization, although greater numbers of primary care practitioners and Federally Qualified Health Centers reduce this type of utilization. Increases in coverage accelerated a long-term increase in ED visits and prevented an even larger decrease in inpatient admissions, but changes in coverage do not fully explain these underlying trends. Increases in primary care supply offset the effects of coverage changes only modestly. Policymakers should not overstate the impact of the Affordable Care Act on increasing ED visits, and should focus on better understanding the underlying factors that are driving the trends.
Dodds, Naomi; Emerson, Philip; Phillips, Stephanie; Green, David R; Jansen, Jan O
2017-03-01
Trauma systems in remote and rural regions often rely on helicopter emergency medical services to facilitate access to definitive care. The siting of such resources is key, but often relies on simplistic modeling of coverage, using circular isochrones. Scotland is in the process of implementing a national trauma network, and there have been calls for an expansion of aeromedical retrieval capacity. The aim of this study was to analyze population and area coverage of the current retrieval service configuration, with three aircraft, and a configuration with an additional helicopter, in the North East of Scotland, using a novel methodology. Both overall coverage and coverage by physician-staffed aircraft, with enhanced clinical capability, were analyzed. This was a geographical analysis based on calculation of elliptical isochrones, which consider the "open-jaw" configuration of many retrieval flights. Helicopters are not always based at hospitals. We modeled coverage based on different outbound and inbound flights. Areally referenced population data were obtained from the Scottish Government. The current helicopter network configuration provides 94.2% population coverage and 59.0% area coverage. The addition of a fourth helicopter would marginally increase population coverage to 94.4% and area coverage to 59.1%. However, when considering only physician-manned aircraft, the current configuration provides only 71.7% population coverage and 29.4% area coverage, which would be increased to 91.1% and 51.2%, respectively, with a second aircraft. Scotland's current helicopter network configuration provides good population coverage for retrievals to major trauma centers, which would only be increased minimally by the addition of a fourth aircraft in the North East. The coverage provided by the single physician-staffed aircraft is more limited, however, and would be increased considerably by a second physician-staffed aircraft in the North East. Elliptical isochrones provide a useful means of modeling "open-jaw" retrieval missions and provide a more realistic estimate of coverage. Epidemiological study, level IV; therapeutic study, level IV.
Shane, Dan M; Wehby, George L
2017-09-01
Oral health problems are the leading chronic conditions among children and younger adults. Lack of dental coverage is thought to be an important barrier to care but little empirical evidence exists on the causal effect of private dental coverage on use of dental services. We explore the relationship between dental coverage and dental services utilization with an analysis of a natural experiment of increasing private dental coverage stemming from the Affordable Care Act's (ACA)-dependent coverage mandate. To evaluate whether increased private dental insurance due to the spillover effect of the ACA-dependent coverage health insurance mandate affected utilization of dental services among a group of affected young adults. 2006-2013 Medical Expenditure Panel Surveys. We used a difference-in-difference regression approach comparing changes in dental care utilization for 25-year olds affected by the policy to unaffected 27-year olds. We evaluate effects on dental treatments and preventive services RESULTS:: Compared to 27-year olds, 25-year olds were 8 percentage points more likely to have private dental coverage in the 3 years following the mandate. We do not find compelling evidence that young adults increased their use of preventive dental services in response to gaining insurance. We do find a nearly 5 percentage point increase in the likelihood of dental treatments among 25-year olds following the mandate, an effect that appears concentrated among women. Increases in private dental coverage due to the ACA's-dependent coverage mandate do not appear to be driving significant changes in overall preventive dental services utilization but there is evidence of an increase in restorative care.
Influence of surface coverage on the chemical desorption process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Minissale, M.; Dulieu, F., E-mail: francois.dulieu@obspm.fr
2014-07-07
In cold astrophysical environments, some molecules are observed in the gas phase whereas they should have been depleted, frozen on dust grains. In order to solve this problem, astrochemists have proposed that a fraction of molecules synthesized on the surface of dust grains could desorb just after their formation. Recently the chemical desorption process has been demonstrated experimentally, but the key parameters at play have not yet been fully understood. In this article, we propose a new procedure to analyze the ratio of di-oxygen and ozone synthesized after O atoms adsorption on oxidized graphite. We demonstrate that the chemical desorptionmore » efficiency of the two reaction paths (O+O and O+O{sub 2}) is different by one order of magnitude. We show the importance of the surface coverage: for the O+O reaction, the chemical desorption efficiency is close to 80% at zero coverage and tends to zero at one monolayer coverage. The coverage dependence of O+O chemical desorption is proved by varying the amount of pre-adsorbed N{sub 2} on the substrate from 0 to 1.5 ML. Finally, we discuss the relevance of the different physical parameters that could play a role in the chemical desorption process: binding energy, enthalpy of formation, and energy transfer from the new molecule to the surface or to other adsorbates.« less
Rajpal, Jaisika; Gupta, Krishna K.; Srivastava, Ruchi; Arora, Aakash
2013-01-01
Gingival recession along with reduced width of attached gingiva and inadequate vestibular depth is a very common finding. Multiple techniques have been developed to obtain predictable root coverage and to increase the width of attached gingiva. Usually, the width of gingiva is first increased and then the second surgery is caried out for root coverage. The newer methods of root coverage are needed, not only to reconstruct the lost periodontal tissues but also to increase predictability, reduce the number of surgical sites, reduce the number of surgeries and improve patient comfort. Hence, this paper describes a single stage technique for increasing the width of attached gingiva and root coverage by using the periosteal pedicle flap. PMID:23869140
NASA Astrophysics Data System (ADS)
Wasey, A. H. M. Abdul; Das, G. P.; Majumder, C.
2017-05-01
Traditionally, h-BN is used as coating material to prevent corrosion on the metal surface. In sharp contrast to this, here we show catalytic behavior of h-BN monolayer deposited on Ni(111) surface, clearly demonstrating the influence of the support in modulation of h-BN electronic structure. Using first principles density functional theory we have studied the interaction of O2 molecules with the h-BN/Ni(111) surface. The activation of Osbnd O bond, which is the most important step for oxidative catalysis, showed dependence on the O2 coverage. Thus this study is extremely important to predict the optimum O2 pressure in reaction chamber for efficient catalysis.
Lister, Kathryn N; Lamare, Miles D; Burritt, David J
2010-06-01
The 'ozone hole' has caused an increase in ultraviolet B radiation (UV-B, 280-320 nm) penetrating Antarctic coastal marine ecosystems, however the direct effect of this enhanced UV-B on pelagic organisms remains unclear. Oxidative stress, the in vivo production of reactive oxygen species to levels high enough to overcome anti-oxidant defences, is a key outcome of exposure to solar radiation, yet to date few studies have examined this physiological response in Antarctic marine species in situ or in direct relation to the ozone hole. To assess the biological effects of UV-B, in situ experiments were conducted at Cape Armitage in McMurdo Sound, Antarctica (77.06 degrees S, 164.42 degrees E) on the common Antarctic sea urchin Sterechinus neumayeri Meissner (Echinoidea) over two consecutive 4-day periods in the spring of 2008 (26-30 October and 1-5 November). The presence of the ozone hole, and a corresponding increase in UV-B exposure, resulted in unequivocal increases in oxidative damage to lipids and proteins, and developmental abnormality in embryos of S. neumayeri growing in open waters. Results also indicate that embryos have only a limited capacity to increase the activities of protective antioxidant enzymes, but not to levels sufficient to prevent severe oxidative damage from occurring. Importantly, results show that the effect of the ozone hole is largely mitigated by sea ice coverage. The present findings suggest that the coincidence of reduced stratospheric ozone and a reduction in sea ice coverage may produce a situation in which significant damage to Antarctic marine ecosystems may occur.
Wehby, George L; Lyu, Wei
2018-04-01
Examine the ACA Medicaid expansion effects on Medicaid take-up and private coverage through 2015 and coverage disparities by age, race/ethnicity, and gender. 2011-2015 American Community Survey for 3,137,989 low-educated adults aged 19-64 years. Difference-in-differences regressions accounting for national coverage trends and state fixed effects. Expansion effects doubled in 2015 among low-educated adults, with a nearly 8 percentage-point increase in Medicaid take-up and 6 percentage-point decline in uninsured rate. Significant coverage gains were observed across virtually all examined groups by age, gender, and race/ethnicity. Take-up and insurance declines were strongest among younger adults and were generally close by gender and race/ethnicity. Despite the increased take-up however, coverage disparities remained sizeable, especially for young adults and Hispanics who had declining but still high uninsured rates in 2015. There was some evidence of private coverage crowd-out in certain subgroups, particularly among young adults aged 19-26 years and women, including in both individually purchased and employer-sponsored coverage. The ACA Medicaid expansions have continued to increase coverage in 2015 across the entire population of low-educated adults and have reduced age disparities in coverage. However, there is still a need for interventions that target eligible young and Hispanic adults. © Health Research and Educational Trust.
Paschoal, Monique Ramos; Cavalcanti, Hannalice Gottschalck; Ferreira, Maria Ângela Fernandes
2017-11-01
This article seeks to establish the coverage of neonatal hearing screening in Brazil between January 2008 and June 2015. It is an ecological study that uses the country, through the Urban Articulation Regions, as a base. To calculate the screening coverage percentage, the Live Births Information System, the Outpatient Information System and the Beneficiaries of the National Supplementary Health Agency Information System were used. An exploratory analysis of maps and spatial statistical analysis was conducted using TerraView 4.2.2 software. The coverage of neonatal hearing screening saw an increase of 9.3% to 37.2% during the study period. In 2008-2009 it was observed that the percentage of coverage ranged from 0% to 79.92%, but most areas received coverage from 0% to 20%, though in 2014-2015 coverage ranged from 0% to 171.77%, and there was a visible increase in the percentage of coverage in the country, mainly in the Southern Region. The screening coverage has increased over time, but is still low with an uneven distribution in the territory, which may be explained by local laws and policies and by the existence of different types of auditory health service in the country.
Deardorff, Katrina V; Rubin Means, Arianna; Ásbjörnsdóttir, Kristjana H; Walson, Judd
2018-02-01
Community-based public health campaigns, such as those used in mass deworming, vitamin A supplementation and child immunization programs, provide key healthcare interventions to targeted populations at scale. However, these programs often fall short of established coverage targets. The purpose of this systematic review was to evaluate the impact of strategies used to increase treatment coverage in community-based public health campaigns. We systematically searched CAB Direct, Embase, and PubMed archives for studies utilizing specific interventions to increase coverage of community-based distribution of drugs, vaccines, or other public health services. We identified 5,637 articles, from which 79 full texts were evaluated according to pre-defined inclusion and exclusion criteria. Twenty-eight articles met inclusion criteria and data were abstracted regarding strategy-specific changes in coverage from these sources. Strategies used to increase coverage included community-directed treatment (n = 6, pooled percent change in coverage: +26.2%), distributor incentives (n = 2, +25.3%), distribution along kinship networks (n = 1, +24.5%), intensified information, education, and communication activities (n = 8, +21.6%), fixed-point delivery (n = 1, +21.4%), door-to-door delivery (n = 1, +14.0%), integrated service distribution (n = 9, +12.7%), conversion from school- to community-based delivery (n = 3, +11.9%), and management by a non-governmental organization (n = 1, +5.8%). Strategies that target improving community member ownership of distribution appear to have a large impact on increasing treatment coverage. However, all strategies used to increase coverage successfully did so. These results may be useful to National Ministries, programs, and implementing partners in optimizing treatment coverage in community-based public health programs.
2018-01-01
Background Community-based public health campaigns, such as those used in mass deworming, vitamin A supplementation and child immunization programs, provide key healthcare interventions to targeted populations at scale. However, these programs often fall short of established coverage targets. The purpose of this systematic review was to evaluate the impact of strategies used to increase treatment coverage in community-based public health campaigns. Methodology/ principal findings We systematically searched CAB Direct, Embase, and PubMed archives for studies utilizing specific interventions to increase coverage of community-based distribution of drugs, vaccines, or other public health services. We identified 5,637 articles, from which 79 full texts were evaluated according to pre-defined inclusion and exclusion criteria. Twenty-eight articles met inclusion criteria and data were abstracted regarding strategy-specific changes in coverage from these sources. Strategies used to increase coverage included community-directed treatment (n = 6, pooled percent change in coverage: +26.2%), distributor incentives (n = 2, +25.3%), distribution along kinship networks (n = 1, +24.5%), intensified information, education, and communication activities (n = 8, +21.6%), fixed-point delivery (n = 1, +21.4%), door-to-door delivery (n = 1, +14.0%), integrated service distribution (n = 9, +12.7%), conversion from school- to community-based delivery (n = 3, +11.9%), and management by a non-governmental organization (n = 1, +5.8%). Conclusions/significance Strategies that target improving community member ownership of distribution appear to have a large impact on increasing treatment coverage. However, all strategies used to increase coverage successfully did so. These results may be useful to National Ministries, programs, and implementing partners in optimizing treatment coverage in community-based public health programs. PMID:29420534
Oxidation of CO by NO on planar and faceted Ir(210)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Wenhua; Bartynski, Robert A.; Kaghazchi, Payam
2012-06-11
Oxidation of CO by pre-adsorbed NO has been studied on planar Ir(210) and nanofaceted Ir(210) with average facet sizes of 5 nm and 14 nm by temperature programmed desorption (TPD). Both surfaces favor oxidation of CO to CO 2, which is accompanied by simultaneous reduction of NO with high selectivity to N 2. At low NO pre-coverage, the temperature (T i) for the onset of CO 2 desorption as well as CO 2 desorption peak temperature (T p) decreases with increasing CO exposure, and NO dissociation is affected by co-adsorbed CO. At high NO pre-coverage, T i and T pmore » are independent of CO exposure, and co-adsorbed CO has no influence on dissociation of NO. Moreover, at low NO pre-coverage, planar Ir(210) is more active than faceted Ir(210) for oxidation of CO to CO 2: T i and T p are much lower on planar Ir(210) than that on faceted Ir(210). In addition, faceted Ir(210) with an average facet size of 5 nm is more active for oxidation of CO to CO 2 than faceted Ir(210) with an average facet size of 14 nm, i.e., oxidation of CO by pre-adsorbed NO on faceted Ir(210) exhibits size effects on the nanometer scale. In comparison, at low O pre-coverage planar Ir(210) is more active than faceted Ir(210) for oxidation of CO to CO 2 but no evidence has been found for size effects in oxidation of CO by pre-adsorbed oxygen on faceted Ir(210) for average facet sizes of 5 nm and 14 nm. The TPD data indicate the same reaction pathway for CO 2 formation from CO + NO and CO + O reactions on planar Ir(210). Lastly, the adsorption sites of CO, NO, O, CO + O, and CO + NO on Ir are characterized by density functional theory.« less
Marital disruption and health insurance.
Peters, H Elizabeth; Simon, Kosali; Taber, Jamie Rubenstein
2014-08-01
Despite the high levels of marital disruption in the United States and the fact that a significant portion of health insurance coverage for those less than age 65 is based on family membership, surprisingly little research is available on the consequences of marital disruption for the health insurance coverage of men, women, and children. We address this shortfall by examining patterns of coverage surrounding marital disruption for men, women, and children, further subset by educational level. Using the 1996, 2001, and 2004 panels of the Survey of Income and Program Participation (SIPP), we find large differences in health insurance coverage across marital status groups in the cross-section. In longitudinal analyses that focus on within-person change, we find small overall coverage changes but large changes in type of coverage following marital disruption. Both men and women show increases in private coverage in their own names, but offsetting decreases in dependent coverage tend to be larger. One surprising result is that dependent coverage for children also declines after marital dissolution, even though children are still likely to be eligible for that coverage. Children and (to a lesser extent) women show increases in public coverage around the time of divorce or separation. We also find that these patterns differ by education. The most vulnerable group appears to be lower-educated women with children because the increases in private, own-name, and public insurance are not large enough to offset the large decrease in dependent coverage. As the United States implements federal health reform, it is critical that we understand the ways in which life course events-specifically, marital disruption-shape the dynamic patterns of coverage.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Lu-Cun; Friend, C. M.; Fushimi, Rebecca
The activation of molecular O 2as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O 2activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O 2dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O 2dissociationmore » is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O 2dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Lu-Cun; Friend, C. M.; Fushimi, Rebecca
2016-01-01
The activation of molecular O 2as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O 2activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O 2dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O 2dissociationmore » is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O 2dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction.« less
Rein, David B; Honeycutt, Amanda A; Rojas-Smith, Lucia; Hersey, James C
2006-09-01
The Centers for Disease Control and Prevention's Section 317 Grants Program is the main source of funding for state and jurisdictional immunization programs, yet no study has evaluated its direct impact on vaccination coverage rates. Therefore, we used a fixed-effects model and data collected from 56 US jurisdictions to estimate the impact of Section 317 financial assistance immunization grants on childhood vaccination coverage rates from 1997 to 2003. Our results showed that increases in Section 317 funding were significantly and meaningfully associated with higher rates of vaccination coverage; a 10 dollars increase in per capita funding corresponded with a 1.6-percentage-point increase in vaccination coverage. Policymakers charged with funding public health programs should consider this study's findings, which indicate that money allocated to vaccine activities translates directly into higher vaccine coverage rates.
Interventions to increase HPV vaccination coverage: A systematic review
Smulian, Elizabeth A.; Mitchell, Krista R.; Stokley, Shannon
2016-01-01
ABSTRACT We reviewed intervention studies designed to increase human papillomavirus (HPV) vaccination coverage to further understand the impact interventions can have on HPV vaccination coverage. We searched 5 databases for intervention studies published from June 2006 to May 2015. Studies were included if they quantitatively measured HPV vaccination coverage as an outcome and were conducted in the United States. We abstracted outcomes, methods, and results from each study and classified by type of intervention conducted. Findings from 34 studies suggest many types of intervention strategies can increase HPV vaccination coverage in different settings, and with modest cost. Interventions were effective especially when implemented in combination at both provider and community levels. However, not all interventions showed significant effects on coverage. More research is needed to identify the best methods for widespread implementation of effective strategies. PMID:26838959
Study of positron annihilation with core electrons at the clean and oxygen covered Ag(001) surface
NASA Astrophysics Data System (ADS)
Joglekar, P.; Shastry, K.; Olenga, A.; Fazleev, N. G.; Weiss, A. H.
2013-03-01
In this paper we present measurements of the energy spectrum of electrons emitted as a result of Positron Annihilation Induce Auger Electron Emission from a clean and oxygen covered Ag (100) surface using a series of incident beam energies ranging from 20 eV down to 2 eV. A peak was observed at ~ 40 eV corresponding to the N23VV Auger transition in agreement with previous PAES studies. Experimental results were investigated theoretically by calculations of positron states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the clean and oxygen covered Ag(100) surface. An ab-initio investigation of stability and associated electronic properties of different adsorption phases of oxygen on Ag(100) has been performed on the basis of density functional theory and using DMOl3 code. The computed positron binding energy, positron surface state wave function, and positron annihilation probabilities of surface trapped positrons with relevant core electrons demonstrate their sensitivity to oxygen coverage, elemental content, atomic structure of the topmost layers of surfaces, and charge transfer effects. Theoretical results are compared with experimental data. This work was supported in part by the National Science Foundation Grant # DMR-0907679.
Surfactant properties of oxygen in the homoepitaxial growth of Fe: a MDS study
NASA Astrophysics Data System (ADS)
Moroni, R.; Bisio, F.; Gussoni, A.; Canepa, M.; Mattera, L.
2001-06-01
The growth of ultra thin iron films (up to a thickness of 5-6 ML) on O(1×1)-Fe/Ag(0 0 1) has been investigated by means of He reflectivity ( RHe) and metastable de-excitation spectroscopy. The presence of oxygen induces a quasi-ideal layer-by-layer growth at variance with the case of the homoepitaxial growth of iron on Fe(0 0 1). The surface electronic density of states suddenly changes upon the deposition of the first half of a monolayer. After the sudden change in the first stages of the growth, the surface density of states of both O 2p and Fe 3d states remains essentially unchanged, irrespectively of the thickness of the deposited film. This provides a clear indication that oxygen floats at the surface acting as a surfactant for the growth of iron on O(1×1)-Fe/Ag(0 0 1). The stationary fraction of oxygen that remains on the topmost layer as growth proceeds depends on the substrate temperature. Post-growth annealing up to 650 K restores the initial coverage of oxygen and the ordered O(1×1) phase.
Kripke, Katharine; Hatzold, Karin; Mugurungi, Owen; Ncube, Gertrude; Xaba, Sinokuthemba; Gold, Elizabeth; Ahanda, Kim Seifert; Kruse-Levy, Natalie; Njeuhmeli, Emmanuel
2016-01-01
Zimbabwe aims to increase circumcision coverage to 80% among 13- to 29-year-olds. However, implementation data suggest that high coverage among men ages 20 and older may not be achievable without efforts specifically targeted to these men, incurring additional costs per circumcision. Scale-up scenarios were created based on trends in implementation data in Zimbabwe, and the cost-effectiveness of increasing efforts to recruit clients ages 20-29 was examined. Zimbabwe voluntary medical male circumcision (VMMC) program data were used to project trends in male circumcision coverage by age into the future. The projection informed a base scenario in which, by 2018, the country achieves 80% circumcision coverage among males ages 10-19 and lower levels of coverage among men above age 20. The Zimbabwe DMPPT 2.0 model was used to project costs and impacts, assuming a US$109 VMMC unit cost in the base scenario and a 3% discount rate. Two other scenarios assumed that the program could increase coverage among clients ages 20-29 with a corresponding increase in unit cost for these age groups. When circumcision coverage among men ages 20-29 is increased compared with a base scenario reflecting current implementation trends, fewer VMMCs are required to avert one infection. If more than 50% additional effort (reflected as multiplying the unit cost by >1.5) is required to double the increase in coverage among this age group compared with the base scenario, the cost per HIV infection averted is higher than in the base scenario. Although increased investment in recruiting VMMC clients ages 20-29 may lead to greater overall impact if recruitment efforts are successful, it may also lead to lower cost-effectiveness, depending on the cost of increasing recruitment. Programs should measure the relationship between increased effort and increased ability to attract this age group.
Sato, Teruyuki; Nakazawa, Misao; Takahashi, Shin; Mizuno, Tomomi; Sato, Akira; Noguchi, Atsuko; Sato, Megumi; Katagiri, Sadako; Yamada, Takechiyo
2018-08-01
Newborn hearing screening (NHS) has been actively performed in Japan since 2001. The NHS coverage rate has increased each year in Akita Prefecture. We analyzed the details of the NHS program and how the Akita leaflets and the many educational offerings about the importance of NHS led to the high NHS coverage rate. A retrospective study was conducted in liveborn newborns in hospitals and in clinics where hearing screening was performed from the program's beginning in 2001 through the end of 2015. We describe the chronological history of NHS. The outcome data of NHS were collected from our department and analyzed. From the founding of the program in 2001 to 2015, the live birth rate in Akita continually declined. Nevertheless, the number of infants receiving NHS rose each year. Since 2012, the coverage rate of NHS has been over 90%. From 2001 to 2015, 75,331 newborns constituted the eligible population for the NHS program. Since 2012, the number of NHS tests has stabilized. We prepared educational leaflets for Akita Prefecture early in 2002. We also provided many educational classes about the importance of NHS for not only pregnant women but also professionals including obstetricians and gynecologists, pediatricians and municipal staff members. The NHS program received the complete endorsement of the Akita Association of Obstetricians and Gynecologists in 2010. The largest increase in the NHS coverage rate occurred from 2001 to 2002, and the second largest increase occurred from 2009 to 2010. The number of participating institutions increased the coverage rate. The coverage rate is strongly correlated with the number of participating institutions (rs=0.843, p<0.001, Spearman's rank correlation coefficient). Comparing the coverage rate for 5 years before and after the Akita Association of Obstetricians and Gynecologists reached their consensus on the importance of NHS, the coverage rate after 2010 was significantly higher than before 2010 (p<0.001, paired sample t-test). The NHS coverage rate ultimately reached 95.4% without need for legislation or subsidization. The number of participating institutions increased each year, and the number of NHS tests and the coverage rate increased proportionately. The number of participating institutions statistically has a strong correlation with the number of NHS tests and the coverage rate. Our research indicates that the Akita leaflets and the provision of educational sessions about the importance of NHS were the most significant factors in establishing the high NHS coverage rate. Copyright © 2017 Elsevier B.V. All rights reserved.
Conversion of 1,2-Propylene Glycol on Rutile TiO2(110)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Long; Li, Zhenjun; Smith, R. Scott
2014-07-17
We have studied the reactions of 1,2-propylene glycol (1,2-PG), DOCH(CH3)CH2OD, on partially reduced, hydroxylated and oxidized TiO2(110) surfaces using temperature programmed desorption. On reduced TiO2(110), propylene, propanal, and acetone are identified as primary carbon-containing products. While the propylene formation channel dominates at low 1,2-PG coverages, all of the above-mentioned products are observed at high coverages. The carbon-containing products are accompanied by the formation of D2O and D2. The observation of only deuterated products shows that the source of hydrogen (D) is from the 1,2-PG hydroxyls. The role of bridging oxygen vacancy (VO) sites was further investigated by titrating them viamore » hydroxylation and oxidation. The results show that hydroxylation does not change the reactivity because the VO sites are regenerated at 500 K, which is a temperature lower than the 1,2-PG product formation temperature. In contrast, surface oxidation causes significant changes in the product distribution, with increased acetone and propanal formation and decreased propylene formation. Additionally D2 is completely eliminated as an observed product at the expense of D2O formation.« less
Redox switching and oxygen evolution at oxidized metal and metal oxide electrodes: iron in base.
Lyons, Michael E G; Doyle, Richard L; Brandon, Michael P
2011-12-28
Outstanding issues regarding the film formation, redox switching characteristics and the oxygen evolution reaction (OER) electrocatalytic behaviour of multicycled iron oxyhydroxide films in aqueous alkaline solution have been revisited. The oxide is grown using a repetitive potential multicycling technique, and the mechanism of the latter hydrous oxide formation process has been discussed. A duplex layer model of the oxide/solution interphase region is proposed. The acid/base behaviour of the hydrous oxide and the microdispersed nature of the latter material has been emphasised. The hydrous oxide is considered as a porous assembly of interlinked octahedrally coordinated anionic metal oxyhydroxide surfaquo complexes which form an open network structure. The latter contains considerable quantities of water molecules which facilitate hydroxide ion discharge at the metal site during active oxygen evolution, and also charge compensating cations. The dynamics of redox switching has been quantified via analysis of the cyclic voltammetry response as a function of potential sweep rate using the Laviron-Aoki electron hopping diffusion model by analogy with redox polymer modified electrodes. Steady state Tafel plot analysis has been used to elucidate the kinetics and mechanism of oxygen evolution. Tafel slope values of ca. 60 mV dec(-1) and ca. 120 mV dec(-1) are found at low and high overpotentials respectively, whereas the reaction order with respect to hydroxide ion activity changes from ca. 3/2 to ca. 1 as the potential is increased. These observations are rationalised in terms of a kinetic scheme involving Temkin adsorption and the rate determining formation of a physisorbed hydrogen peroxide intermediate on the oxide surface. The dual Tafel slope behaviour is ascribed to the potential dependence of the surface coverage of adsorbed intermediates.
Effects of ACA Medicaid Expansions on Health Insurance Coverage and Labor Supply.
Kaestner, Robert; Garrett, Bowen; Chen, Jiajia; Gangopadhyaya, Anuj; Fleming, Caitlyn
We examined the effect of the expansion of Medicaid eligibility under the Affordable Care Act on health insurance coverage and labor supply of low-educated and low-income adults. We found that the Medicaid expansions were associated with large increases in Medicaid coverage, for example, 50 percent among childless adults, and corresponding decreases in the proportion uninsured. There was relatively little change in private insurance coverage, although the expansions tended to decrease such coverage slightly. In terms of labor supply, estimates indicated that the Medicaid expansions had little effect on work effort despite the substantial changes in health insurance coverage. Most estimates suggested that the expansions increased work effort, although not significantly.
Liu, Jun-Hui; Gao, Ji-Xi
2008-09-01
Based on the remote sensing images and the meteorological data in 1986 and 2000, and by using the model of extracting vegetation coverage, the spatiotemporal changes of vegetation coverage in the farming-pastoral ecotone of Northern China in 1986-2000 were studied, with the effects of climate and land use change on the changes analyzed. The results showed that in this ecotone, the area with lower vegetation coverage was increasing, while that with higher vegetation coverage was in adverse. The regions with increasing vegetation coverage were mainly in the east of northeast section, the west of north section, and the west of northwest section of the ecotone, while the vegetation coverage in the other sections was obviously degraded. The vegetation coverage were positively correlated with precipitation and aridity index, but negatively correlated with temperature. The change direction and extent of the vegetation coverage varied with land use types.
Rein, David B.; Honeycutt, Amanda A.; Rojas-Smith, Lucia; Hersey, James C.
2006-01-01
The Centers for Disease Control and Prevention’s Section 317 Grants Program is the main source of funding for state and jurisdictional immunization programs, yet no study has evaluated its direct impact on vaccination coverage rates. Therefore, we used a fixed-effects model and data collected from 56 US jurisdictions to estimate the impact of Section 317 financial assistance immunization grants on childhood vaccination coverage rates from 1997 to 2003. Our results showed that increases in Section 317 funding were significantly and meaningfully associated with higher rates of vaccination coverage; a $10 increase in per capita funding corresponded with a 1.6-percentage-point increase in vaccination coverage. Policymakers charged with funding public health programs should consider this study’s findings, which indicate that money allocated to vaccine activities translates directly into higher vaccine coverage rates. PMID:16873738
Wallace, Aaron S.; Ryman, Tove K.; Dietz, Vance
2015-01-01
Background Review of the historical growth in annual vaccination coverage across countries and regions can better inform decision makers’ development of future goals and strategies to improve routine vaccination services. Methods Using the World Health Organization (WHO) and the United Nations Children's Fund estimates of annual national third dose of diphtheria-tetanus-pertussis–containing vaccine (DTP3) and third dose of polio vaccine (POL3) coverage for 1980–2009, we calculated the mean absolute annual rate of change in national DTP3 coverage among all countries (globally) and among countries within each WHO region, as well as the number of years taken by each region to reach specific regional coverage levels. Last, we assessed differences in mean absolute annual rate of change in DTP3 coverage, stratified by baseline level of DTP3 coverage. Results During the 1980s, global DTP3 coverage increased a mean of 5.3 percentage points/year. Annual rate of change decreased to 0.5 percentage points/year in the 1990s and then increased to 0.9 percentage points/year during the 2000s. Mean annual rate of change in coverage across all countries was highest (9.2 percentage points) when national coverage levels were 26%–30% and lowest (−0.9 percentage points) when national coverage levels were 96%–100%. Regional differences existed as both WHO South-East Asia Region and WHO African Region countries experienced mean negative DTP3 coverage growth at lower coverage levels (81%–85%) than other regions. The regions that have achieved 95% DTP3 coverage (Americas, Western Pacific, and European) took 25–29 years to reach that level from a level of 50% DTP3 coverage. POL3 coverage change trends were similar to described DTP3 coverage change trends. Conclusions Mean national coverage growth patterns across all regions are nonlinear as coverage levels increase. Saturation points of mean 0 percentage-point growth in annual coverage varies by region and require further investigation. The achievement of >90% routine coverage is observed to take decades, which has implications for disease eradication and elimination initiatives. PMID:25316875
Oxygen adsorption on a Si(1 0 0) substrate: effects on secondary emission properties
NASA Astrophysics Data System (ADS)
Vogan, W. S.; Champion, R. L.
2001-10-01
Secondary anion and electron yields resulting from low-energy (50-500 eV) Na + bombardment of an oxygen-adsorbed Si(1 0 0) substrate have been measured as a function of oxygen exposure and of Na + impact energy. Adsorbate coverage ranges from none to over half a monolayer. The dominant sputtered anion was found to be O - with SiO 2- being a minor constituent. Kinetic energy distributions of the secondary anions and electrons were also measured. The presence of an adsorbate was observed to enhance secondary anion emission to a significant degree whereas secondary electron emission was minor, in sharp contrast to what has been observed for metallic substrates. The mechanism for secondary emission appears to involve electronic excitation of Si xO -; it is suggested that electron emission is governed by a process similar to Penning ionization, in which a vacancy created by the excitation of Si xO - may be filled by an electron from the valence band. The variation in the work function as oxygen accumulated on the surface was observed to be small.
NASA Astrophysics Data System (ADS)
Vattuone, L.; Gerbi, A.; Savio, L.; Cappelletti, D.; Pirani, F.; Rocca, M.
2010-05-01
We report on stereodynamical effects in heterogeneous catalytic reactions as measured by molecular beam-surface experiments. Specifically for CO oxidation on Pd(100) we find that the rotational alignment of the incoming O2 at low (Θ = 0.04 ML) and at intermediate (ΘCO = 0.17 ML) CO pre-coverage, causes a higher reactivity of molecules in high and in low helicity states, respectively (corresponding to helicoptering and cartwheeling motion of O2). In first approximation, at low CO pre-coverage the difference in reactivity is determined by the different location of the O atoms generated in the dissociation process by the different parent molecules, while at intermediate CO pre-coverage the reactivity is influenced also by the different ability of cartwheeling and helicoptering O2 to penetrate through the CO adlayer. In accord with this the total amount of CO2 produced is always largest for helicopters which generate supersurface O atoms at least in the low CO pre-coverage limit. A deeper inspection of the data indicates, however, that the dynamics is more complex, two different pathways being present for the reaction with O generated by helicopters and one for O generated by cartwheels. Moreover, cartwheels generated oxygen influences the reactivity of subsequently arriving helicopters.
Kumar, Chandan; Singh, Prashant Kumar; Rai, Rajesh Kumar
2013-12-01
Increasing the coverage of key maternal, newborn and child health interventions is essential, if India has to attain Millennium Development Goals 4 and 5. This study assesses the coverage gap in maternal and child health services across states in India during 1992-2006 emphasizing the rural-urban disparities. Additionally, association between the coverage gap and under-5 mortality rate across states are illustrated. The three waves of National Family Health Survey (NFHS) conducted during 1992-1993 (NFHS-1), 1998-1999 (NFHS-2) and 2005-2006 (NFHS-3) were used to construct a composite index of coverage gap in four areas of health-care interventions: family planning, maternal and newborn care, immunization and treatment of sick children. The central, eastern and northeastern regions of India reported a higher coverage gap in maternal and child health care services during 1992-2006, while the rural-urban difference in the coverage gap has increased in Gujarat, Haryana, Rajasthan and Kerala over the period. The analysis also shows a significant positive relationship between the coverage gap index and under-five mortality rate across states. Region or area-specific focus in order to increase the coverage of maternal and child health care services in India should be the priority of the policy-makers and programme executors.
Oxygen in the Southern Ocean From Argo Floats: Determination of Processes Driving Air-Sea Fluxes
NASA Astrophysics Data System (ADS)
Bushinsky, Seth M.; Gray, Alison R.; Johnson, Kenneth S.; Sarmiento, Jorge L.
2017-11-01
The Southern Ocean is of outsized significance to the global oxygen and carbon cycles with relatively poor measurement coverage due to harsh winters and seasonal ice cover. In this study, we use recent advances in the parameterization of air-sea oxygen fluxes to analyze 9 years of oxygen data from a recalibrated Argo oxygen data set and from air-calibrated oxygen floats deployed as part of the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project. From this combined data set of 150 floats, we find a total Southern Ocean oxygen sink of -183 ± 80 Tmol yr-1 (positive to the atmosphere), greater than prior estimates. The uptake occurs primarily in the Polar-Frontal Antarctic Zone (PAZ, -94 ± 30 Tmol O2 yr-1) and Seasonal Ice Zone (SIZ, -111 ± 9.3 Tmol O2 yr-1). This flux is driven by wintertime ventilation, with a large portion of the flux in the SIZ passing through regions with fractional sea ice. The Subtropical Zone (STZ) is seasonally driven by thermal fluxes and exhibits a net outgassing of 47 ± 29 Tmol O2 yr-1 that is likely driven by biological production. The Subantarctic Zone (SAZ) uptake is -25 ± 12 Tmol O2 yr-1. Total oxygen fluxes were separated into a thermal and nonthermal component. The nonthermal flux is correlated with net primary production and mixed layer depth in the STZ, SAZ, and PAZ, but not in the SIZ where seasonal sea ice slows the air-sea gas flux response to the entrainment of deep, low-oxygen waters.
Did the Affordable Care Act's dependent coverage mandate increase premiums?
Depew, Briggs; Bailey, James
2015-05-01
We investigate the impact of the Affordable Care Act's dependent coverage mandate on insurance premiums. The expansion of dependent coverage under the ACA allows young adults to remain on their parent's private health insurance plans until the age of 26. We find that the mandate has led to a 2.5-2.8 percent increase in premiums for health insurance plans that cover children, relative to single-coverage plans. We are able to conclude that employers did not pass on the entire premium increase to employees through higher required plan contributions. Copyright © 2015 Elsevier B.V. All rights reserved.
Ji, Xu; Wilk, Adam S; Druss, Benjamin G; Lally, Cathy; Cummings, Janet R
2017-08-01
Gaps in Medicaid coverage may disrupt access to and continuity of care. This can be detrimental for beneficiaries with chronic conditions, such as major depression, for whom disruptions in access to outpatient care may lead to increased use of acute care. However, little is known about how Medicaid coverage discontinuities impact acute care utilization among adults with depression. Examine the relationship between Medicaid discontinuities and service utilization among adults with major depression. A total of 139,164 adults (18-64) with major depression was identified using the 2003-2004 Medicaid Analytic eXtract Files. We used generalized linear and two-part models to examine the effect of Medicaid discontinuity on service utilization. To establish causality in this relationship, we used instrumental variables analysis, relying on exogenous variation in a state-level policy for identification. Emergency department (ED) visits, inpatient episodes, inpatient days, and Medicaid-reimbursed costs. Approximately 29.4% of beneficiaries experienced coverage disruptions. In instrumental variables models, those with coverage disruptions incurred an increase of $650 in acute care costs per-person per Medicaid-covered month compared with those with continuous coverage, evidenced by an increase in ED use (0.1 more ED visits per-person-month) and inpatient days (0.6 more days per-person-month). The increase in acute costs contributed to an overall increase in all-cause costs by $310 per-person-month (all P-values<0.001). Among depressed adults, those experiencing coverage disruptions have, on average, significantly greater use of costly ED/inpatient services than those with continuous coverage. Maintenance of continuous Medicaid coverage may help prevent acute episodes requiring high-cost interventions.
Medicaid Coverage Expansions and Cigarette Smoking Cessation Among Low-income Adults.
Koma, Jonathan W; Donohue, Julie M; Barry, Colleen L; Huskamp, Haiden A; Jarlenski, Marian
2017-12-01
Expanding Medicaid coverage to low-income adults may have increased smoking cessation through improved access to evidence-based treatments. Our study sought to determine if states' decisions to expand Medicaid increased recent smoking cessation. Using pooled cross-sectional data from the Behavioral Risk Factor Surveillance Survey for the years 2011-2015, we examined the association between state Medicaid coverage and the probability of recent smoking cessation among low-income adults without dependent children who were current or former smokers (n=36,083). We used difference-in-differences estimation to examine the effects of Medicaid coverage on smoking cessation, comparing low-income adult smokers in states with Medicaid coverage to comparable adults in states without Medicaid coverage, with ages 18-64 years to those ages 65 years and above. Analyses were conducted for the full sample and stratified by sex. Residence in a state with Medicaid coverage among low-income adult smokers ages 18-64 years was associated with an increase in recent smoking cessation of 2.1 percentage points (95% confidence interval, 0.25-3.9). In the comparison group of individuals ages 65 years and above, residence in a state with Medicaid coverage expansion was not associated with a change in recent smoking cessation (-0.1 percentage point, 95% confidence interval, -2.1 to 1.8). Similar increases in smoking cessation among those ages 18-64 years were estimated for females and males (1.9 and 2.2 percentage point, respectively). Findings are consistent with the hypothesis that Medicaid coverage expansions may have increased smoking cessation among low-income adults without dependent children via greater access to preventive health care services, including evidence-based smoking cessation services.
Potential-specific structure at the hematite-electrolyte interface
DOE Office of Scientific and Technical Information (OSTI.GOV)
McBriarty, Martin E.; Stubbs, Joanne; Eng, Peter
The atomic-scale structure of interfaces between metal oxides and aqueous electrolytes controls their catalytic, geochemical, and corrosion behavior. Measurements that probe these interfaces in situ provide important details of ion and solvent arrangements, but atomically precise structural models do not exist for common oxide-electrolyte interfaces far from equilibrium. Using a novel cell, we measured the structure of the hematite (a-Fe 2O 3) (110more » $$\\bar{2}$$)-electrolyte interface under controlled electrochemical bias using synchrotron crystal truncation rod X ray scattering. At increasingly cathodic potentials, charge-compensating protonation of surface oxygen groups increases the coverage of specifically bound water while adjacent water layers displace outwardly and became disordered. Returning to open circuit potential leaves the surface in a persistent metastable protonation state. The flux of current and ions at applied potential is thus regulated by a unique interfacial electrolyte environment, suggesting that electrical double layer models should be adapted to the dynamically changing interfacial structure far from equilibrium.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Khare, Rohit; Srivastava, Ashutosh; Donnelly, Vincent M.
2012-09-15
Chlorine atom recombination coefficients were measured on silicon oxy-chloride surfaces deposited in a chlorine inductively coupled plasma (ICP) with varying oxygen concentrations, using the spinning wall technique. A small cylinder embedded in the walls of the plasma reactor chamber was rapidly rotated, repetitively exposing its surface to the plasma chamber and a differentially pumped analysis chamber housing a quadruple mass spectrometer for line-of-sight desorbing species detection, or an Auger electron spectrometer for in situ surface analysis. The spinning wall frequency was varied from 800 to 30 000 rpm resulting in a detection time, t (the time a point on themore » surface takes to rotate from plasma chamber to the position facing the mass or Auger spectrometer), of {approx}1-40 ms. Desorbing Cl{sub 2}, due to Langmuir-Hinshelwood (LH) Cl atom recombination on the reactor wall surfaces, was detected by the mass spectrometer and also by a pressure rise in one of the differentially pumped chambers. LH Cl recombination coefficients were calculated by extrapolating time-resolved desorption decay curves to t = 0. A silicon-covered electrode immersed in the plasma was either powered at 13 MHz, creating a dc bias of -119 V, or allowed to electrically float with no bias power. After long exposure to a Cl{sub 2} ICP without substrate bias, slow etching of the Si wafer coats the chamber and spinning wall surfaces with an Si-chloride layer with a relatively small amount of oxygen (due to a slow erosion of the quartz discharge tube) with a stoichiometry of Si:O:Cl = 1:0.38:0.38. On this low-oxygen-coverage surface, any Cl{sub 2} desorption after LH recombination of Cl was below the detection limit. Adding 5% O{sub 2} to the Cl{sub 2} feed gas stopped etching of the Si wafer (with no rf bias) and increased the oxygen content of the wall deposits, while decreasing the Cl content (Si:O:Cl = 1:1.09:0.08). Cl{sub 2} desorption was detectable for Cl recombination on the spinning wall surface coated with this layer, and a recombination probability of {gamma}{sub Cl} = 0.03 was obtained. After this surface was conditioned with a pure oxygen plasma for {approx}60 min, {gamma}{sub Cl} increased to 0.044 and the surface layer was slightly enriched in oxygen fraction (Si:O:Cl = 1:1.09:0.04). This behavior is attributed to a mechanism whereby Cl LH recombination occurs mainly on chlorinated oxygen sites on the silicon oxy-chloride surface, because of the weak Cl-O bond compared to the Cl-Si bond.« less
Premium growth and its effect on employer-sponsored insurance.
Vistnes, Jessica; Selden, Thomas
2011-03-01
We use variation in premium inflation and general inflation across geographic areas to identify the effects of downward nominal wage rigidity on employers' health insurance decisions. Using employer level data from the 2000 to 2005 Medical Expenditure Panel Survey-Insurance Component, we examine the effect of premium growth on the likelihood that an employer offers insurance, eligibility rates among employees, continuous measures of employee premium contributions for both single and family coverage, and deductibles. We find that small, low-wage employers are less likely to offer health insurance in response to increased premium inflation, and if they do offer coverage they increase employee contributions and deductible levels. In contrast, larger, low-wage employers maintain their offers of coverage, but reduce eligibility for such coverage. They also increase employee contributions for single and family coverage, but not deductibles. Among high-wage employers, all but the largest increase deductibles in response to cost pressures.
NASA Astrophysics Data System (ADS)
Smolinsky, Tim; von Boehn, Bernhard; Imbihl, Ronald
2018-04-01
Chemical waves that arise in the H2 + O2 reaction on a bimetallic Rh(111)/Ni surface have been studied in the 10-6 and 10-5 mbar range at T = 773 K with photoelectron emission microscopy (PEEM), low-energy electron diffraction (LEED), and Auger electron spectroscopy (AES). Nickel coverages of 0.3, 0.6, and 1.0 monolayers were investigated. Coadsorbed with some oxygen, Ni starts to penetrate the Rh bulk region substantially only beyond 900 K. In the 10-5 mbar range, chemical waves are characterized by three distinct gray levels in PEEM. This number reduces to only two levels in the 10-6 mbar range. In situ LEED showed the periodic appearance of a (n × 1) (n = 8, 10) pattern during chemical waves which was assigned to a 2D-Ni oxide. With in situ AES, one observes that the bright phase in PEEM correlates with a high Ni coverage and the dark phase with a low Ni coverage.
Becton, James L; Cheng, Lee; Nieman, Linda Z
2008-04-01
Previous studies found that the increasing number of paediatricians in the United States was associated with improved childhood immunization coverage, while the increasing poverty level and the lack of health insurance reduced access to health care. We evaluated whether changes in the number of paediatricians, poverty level and health insurance affected national childhood immunization coverage in the state levels of the United States. Data were collected primarily from the US National Immunization Surveys, series 4:3:1:3:3 from years 1995 and 2003. Ordinal logistic regression analysis was used to analyse the relationships among variables. Over 8 years studied, immunization coverage increased for children aged 19-35 months from 52.3% to 79.8% in the 50 states. The average number of paediatricians per 1000 births increased 28.7% while the percentage of children without health insurance declined 15.6%, and the percentage of children who lived in poverty level declined 17.3%. In 1995, the states with higher immunization coverage were associated with higher numbers of paediatricians [odds ratio (OR), 32.73; 95% confidence interval (CI), 5.96-179.77]. In 2003, the higher numbers of paediatricians still played a role in the increased immunization coverage (OR, 4.69; 95% CI, 1.01-21.78); however, the higher rate of uninsured children in 2003 had an even greater effect upon immunization coverage. Compared with states with lower rates of uninsured children, states with intermediate and higher rates of uninsured children had sixfold (OR, 0.16; 95% CI, 0.03-0.81) and 16-fold (OR, 0.06; 95% CI, 0.01-0.40) decreased childhood immunization coverage, respectively. Between 1995 and 2003 in the United States, the lack of health insurance became more prominent than the supply of paediatricians in affecting immunization coverage for children aged 19-35 months. Future improvements in insurance coverage for children will likely lead to greater immunization coverage.
Mosaly, Prithima R; Mazur, Lukasz M; Jones, Ellen L; Hoyle, Lesley; Zagar, Timothy; Chera, Bhishamjit S; Marks, Lawrence B
2013-01-01
To quantitatively assess the difference in workload and performance of radiation oncology physicians during radiation therapy treatment planning tasks under the conditions of "cross coverage" versus planning a patient with whom they were familiar. Eight physicians (3 experienced faculty physicians and 5 physician residents) performed 2 cases. The first case represented a "cross-coverage" scenario where the physicians had no prior information about the case to be planned. The second exposure represented a "regular-coverage" scenario where the physicians were familiar with the patient case to be planned. Each case involved 3 tasks to be completed systematically. Workload was assessed both subjectively (perceived) using National Aeronautics and Space Administration-Task Load Index (NASA-TLX), and objectively (physiological) throughout the task using eye data (via monitoring pupil size and blink rate). Performance of each task and the case was measured using completion time. Subjective willingness to approve or disapprove the generated plan was obtained after completion of the case only. Forty-eight perceived and 48 physiological workload assessments were obtained. Overall, results revealed a significant increase in perceived workload (high NASA-TLX score) and decrease in performance (longer completion time and reduced approval rate) during cross coverage. There were nonsignificant increases in pupil diameter and decreases in the blink rate during cross-coverage versus regular-coverage scenario. In both cross-coverage and regular-coverage scenarios the level of experience did not affect workload and performance. The cross-coverage scenario significantly increases perceived workload and degrades performance versus regular coverage. Hence, to improve patient safety, efforts must be made to develop policies, standard operating procedures, and usability improvements to electronic medical record and treatment planning systems for "easier" information processing to deal with cross coverage, while recognizing strengths and limitations of human performance. Published by Elsevier Inc.
Cooper, Philip F; Vistnes, Jessica
2003-07-01
Many proposed policy initiatives involve subsidies directed toward encouraging employers to offer coverage and toward workers to encourage enrollment in offered plans. Given that insurance coverage reflects employers' decisions to offer coverage, eligibility requirements for such coverage, and employees' take-up decisions, all three elements are important when considering mechanisms to decrease the number of uninsured individuals. In this study, we examine the relationship between workers' decisions to take-up offers of health insurance and annual out-of-pocket contributions, total premiums, and employer and workforce characteristics. We model the take-up decision using cross-sectional data from approximately 18,000 establishments per year from the 1997 to 1999 Medical Expenditure Panel Survey - Insurance Component. We find that workers are less likely to enroll in coverage as single employee contributions increase. Our results for family contributions are much smaller than for single contributions and are not statistically significant in all years. Our simulation results suggest that reducing employee contribution levels for single coverage from existing levels in 1999 to zero would yield an increase in take-up rates of roughly 6% points in establishments that had required a positive level of contributions. Our results also indicate that of the 13.8 million private sector workers who decline coverage from their employers, 2.5 million would potentially enroll in employer-sponsored coverage if the cost of single coverage were to fall to zero. Reducing employee contributions will increase take-up rates; however, even when employees pay nothing for their coverage, some employees elect not to enroll.
Look, Kevin A; Kim, Nam Hyo; Arora, Prachi
2017-01-01
To evaluate the impact of the Affordable Care Act's (ACA) dependent coverage mandate on insurance coverage among young adults in metropolitan and nonmetropolitan areas. A cross-sectional analysis was conducted using data from 2006-2009 and 2011 waves of the Medical Expenditure Panel Survey. A difference-in-difference analysis was used to compare changes in full-year private health insurance coverage among young adults aged 19-25 years with an older cohort aged 27-34 years. Separate regressions were estimated for individuals in metropolitan and nonmetropolitan areas and were tested for a differential impact by area of residence. Full-year private health insurance coverage significantly increased by 9.2 percentage points for young adults compared to the older cohort after the ACA mandate (P = .00). When stratifying the regression model by residence area, insurance coverage among young adults significantly increased by 9.0 percentage points in metropolitan areas (P = .00) and 10.1 percentage points in nonmetropolitan areas (P = .03). These changes were not significantly different from each other (P = .82), which suggests the ACA mandate's effects were not statistically different by area of residence. Although young adults in metropolitan and nonmetropolitan areas experienced increased access to private health insurance following the ACA's dependent coverage mandate, it did not appear to directly impact rural-urban disparities in health insurance coverage. Despite residents in both areas gaining insurance coverage, over one-third of young adults still lacked access to full-year health insurance coverage. © 2016 National Rural Health Association.
Hansen, Carolina Malta; Lippert, Freddy Knudsen; Wissenberg, Mads; Weeke, Peter; Zinckernagel, Line; Ruwald, Martin H; Karlsson, Lena; Gislason, Gunnar Hilmar; Nielsen, Søren Loumann; Køber, Lars; Torp-Pedersen, Christian; Folke, Fredrik
2014-11-18
Although increased dissemination of automated external defibrillators (AEDs) has been associated with more frequent AED use, the trade-off between the number of deployed AEDs and coverage of cardiac arrests remains unclear. We investigated how volunteer-based AED dissemination affected public cardiac arrest coverage in high- and low-risk areas. All public cardiac arrests (1994-2011) and all registered AEDs (2007-2011) in Copenhagen, Denmark, were identified and geocoded. AED coverage of cardiac arrests was defined as historical arrests ≤100 m from an AED. High-risk areas were defined as those with ≥1 arrest every 2 years and accounted for 1.0% of the total city area. Of 1864 cardiac arrests, 18.0% (n=335) occurred in high-risk areas throughout the study period. From 2007 to 2011, the number of AEDs and the corresponding coverage of cardiac arrests increased from 36 to 552 and from 2.7% to 32.6%, respectively. The corresponding increase for high-risk areas was from 1 to 30 AEDs and coverage from 5.7% to 51.3%, respectively. Since the establishment of the AED network (2007-2011), few arrests (n=55) have occurred ≤100 m from an AED with only 14.5% (n=8) being defibrillated before the arrival of emergency medical services. Despite the lack of a coordinated public access defibrillation program, the number of AEDs increased 15-fold with a corresponding increase in cardiac arrest coverage from 2.7% to 32.6% over a 5-year period. The highest increase in coverage was observed in high-risk areas (from 5.7% to 51.3%). AED networks can be used as useful tools to optimize AED placement in community settings. © 2014 American Heart Association, Inc.
Effect of oxygen, methyl mercaptan, and methyl chloride on friction behavior of copper-iron contacts
NASA Technical Reports Server (NTRS)
Buckley, D. H.
1978-01-01
Sliding friction experiments were conducted with an iron rider on a copper disk and a copper rider on an iron disk. The sputter cleaned iron and copper disk surfaces were saturated with oxygen, methyl mercaptan, and methyl chloride at atmospheric pressure. Auger emission spectroscopy was used to monitor the surfaces. Lower friction was obtained in all experiments with the copper rider sliding on the iron disk than when the couple was reversed. For both iron and copper disks, methyl mercaptan gave the best surface coverage and was most effective in reducing friction. For both iron and copper disks, methyl chloride was the least effective in reducing friction. With sliding, copper transferred to iron and iron to copper.
Berry, David A; Shekhawat, Dushyant; Smith, Mark; Haynes, Daniel
2013-07-16
The disclosure relates to a method of utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream with a mitigation of carbon accumulation. The system is comprised of a catalytically active phase deposited onto an oxygen conducting phase, with or without supplemental support. The catalytically active phase has a specified crystal structure where at least one catalytically active metal is a cation within the crystal structure and coordinated with oxygen atoms within the crystal structure. The catalyst system employs an optimum coverage ratio for a given set of oxidation conditions, based on a specified hydrocarbon conversion and a carbon deposition limit. Specific embodiments of the catalyst system are disclosed.
Childhood Malaria Admission Rates to Four Hospitals in Malawi between 2000 and 2010
Okiro, Emelda A.; Kazembe, Lawrence N.; Kabaria, Caroline W.; Ligomeka, Jeffrey; Noor, Abdisalan M.; Ali, Doreen; Snow, Robert W.
2013-01-01
Introduction The last few years have witnessed rapid scaling-up of key malaria interventions in several African countries following increases in development assistance. However, there is only limited country-specific information on the health impact of expanded coverage of these interventions. Methods Paediatric admission data were assembled from 4 hospitals in Malawi reflecting different malaria ecologies. Trends in monthly clinical malaria admissions between January 2000 and December 2010 were analysed using time-series models controlling for covariates related to climate and service use to establish whether changes in admissions can be related to expanded coverage of interventions aimed at reducing malaria infection. Results In 3 of 4 sites there was an increase in clinical malaria admission rates. Results from time series models indicate a significant month-to-month increase in the mean clinical malaria admission rates at two hospitals (trend P<0.05). At these hospitals clinical malaria admissions had increased from 2000 by 41% to 100%. Comparison of changes in malaria risk and ITN coverage appear to correspond to a lack of disease declines over the period. Changes in intervention coverage within hospital catchments showed minimal increases in ITN coverage from <6% across all sites in 2000 to maximum of 33% at one hospital site by 2010. Additionally, malaria transmission intensity remained unchanged between 2000–2010 across all sites. Discussion Despite modest increases in coverage of measures to reduce infection there has been minimal changes in paediatric clinical malaria cases in four hospitals in Malawi. Studies across Africa are increasingly showing a mixed set of impact results and it is important to assemble more data from more sites to understand the wider implications of malaria funding investment. We also caution that impact surveillance should continue in areas where intervention coverage is increasing with time, for example Malawi, as decline may become evident within a period when coverage reaches optimal levels. PMID:23638008
Noar, Seth M; Ribisl, Kurt M; Althouse, Benjamin M; Willoughby, Jessica Fitts; Ayers, John W
2013-12-01
Announcements of cancer diagnoses from public figures may stimulate cancer information seeking and media coverage about cancer. This study used digital surveillance to quantify the effects of pancreatic cancer public figure announcements on online cancer information seeking and cancer media coverage. We compiled a list of public figures (N = 25) who had been diagnosed with or had died from pancreatic cancer between 2006 and 2011. We specified interrupted time series models using data from Google Trends to examine search query shifts for pancreatic cancer and other cancers. Weekly media coverage archived on Google News were also analyzed. Most public figures' pancreatic cancer announcements corresponded with no appreciable change in pancreatic cancer search queries or media coverage. In contrast, Patrick Swayze's diagnosis was associated with a 285% (95% confidence interval [CI]: 212 to 360) increase in pancreatic cancer search queries, though it was only weakly associated with increases in pancreatic cancer media coverage. Steve Jobs's death was associated with a 197% (95% CI: 131 to 266) increase in pancreatic cancer queries and a 3517% (95% CI: 2882 to 4492) increase in pancreatic cancer media coverage. In general, a doubling in pancreatic cancer-specific media coverage corresponded with a 325% increase in pancreatic cancer queries. Digital surveillance is an important tool for future cancer control research and practice. The current application of these methods suggested that pancreatic cancer announcements (diagnosis or death) by particular public figures stimulated media coverage of and online information seeking for pancreatic cancer.
Hospital emergency on-call coverage: is there a doctor in the house?
O'Malley, Ann S; Draper, Debra A; Felland, Laurie E
2007-11-01
The nation's community hospitals face increasing problems obtaining emergency on-call coverage from specialist physicians, according to findings from the Center for Studying Health System Change's (HSC) 2007 site visits to 12 nationally representative metropolitan communities. The diminished willingness of specialist physicians to provide on-call coverage is occurring as hospital emergency departments confront an ever-increasing demand for services. Factors influencing physician reluctance to provide on-call coverage include decreased dependence on hospital admitting privileges as more services shift to non-hospital settings; payment for emergency care, especially for uninsured patients; and medical liability concerns. Hospital strategies to secure on-call coverage include enforcing hospital medical staff bylaws that require physicians to take call, contracting with physicians to provide coverage, paying physicians stipends, and employing physicians. Nonetheless, many hospitals continue to struggle with inadequate on-call coverage, which threatens patients' timely access to high-quality emergency care and may raise health care costs.
Giorgi Rossi, Paolo; Carrozzi, Giuliano; Federici, Antonio; Mancuso, Pamela; Sampaolo, Letizia; Zappa, Marco
2018-03-01
Objectives In Italy, regional governments organize cervical, breast and colorectal cancer screening programmes, but there are difficulties in regularly inviting all the target populations and participation remains low. We analysed the determinants associated with invitation coverage of and participation in these programmes. Methods We used data on screening programmes from annual Ministry of Health surveys, 1999-2012 for cervical, 1999-2011 for breast and 2005-2011 for colorectal cancer. For recent years, we linked these data to the results of the national routine survey on preventive behaviours to evaluate the effect of spontaneous screening at Province level. Invitation and participation relative risk were calculated using Generalized Linear Models. Results There is a strong decreasing trend in invitation coverage and participation in screening programmes from North to South Italy. In metropolitan areas, both invitation coverage (rate ratio 0.35-0.96) and participation (rate ratio 0.63-0.88) are lower. An inverse association exists between spontaneous screening and both screening invitation coverage (1-3% decrease in invitation coverage per 1% spontaneous coverage increase) and participation (2% decrease in participation per 1% spontaneous coverage increase) for the three programmes. High recall rate has a negative effect on invitation coverage in the next round for breast cancer (1% decrease in invitation per 1% recall increase). Conclusions Organizational and cultural changes are needed to better implement cancer screening in southern Italy.
Arroyave, Ivan; Cardona, Doris; Burdorf, Alex
2013-01-01
Objectives. We examined the impact of expanding health insurance coverage on socioeconomic disparities in total and cardiovascular disease mortality from 1998 to 2007 in Colombia. Methods. We used Poisson regression to analyze data from mortality registries (633 905 deaths) linked to population census data. We used the relative index of inequality to compare disparities in mortality by education between periods of moderate increase (1998–2002) and accelerated increase (2003–2007) in health insurance coverage. Results. Disparities in mortality by education widened over time. Among men, the relative index of inequality increased from 2.59 (95% confidence interval [CI] = 2.52, 2.67) in 1998–2002 to 3.07 (95% CI = 2.99, 3.15) in 2003–2007, and among women, from 2.86 (95% CI = 2.77, 2.95) to 3.12 (95% CI = 3.03, 3.21), respectively. Disparities increased yearly by 11% in men and 4% in women in 1998–2002, whereas they increased by 1% in men per year and remained stable among women in 2003–2007. Conclusions. Mortality disparities widened significantly less during the period of increased health insurance coverage than the period of no coverage change. Although expanding coverage did not eliminate disparities, it may contribute to curbing future widening of disparities. PMID:23327277
Lanthony, Cloé; Guiltat, Mathilde; Ducéré, Jean Marie; Verdier, Agnes; Hémeryck, Anne; Djafari-Rouhani, Mehdi; Rossi, Carole; Chabal, Yves J; Estève, Alain
2014-09-10
The surface chemistry associated with the synthesis of energetic nanolaminates controls the formation of the critical interfacial layers that dominate the performances of nanothermites. For instance, the interaction of Al with CuO films or CuO with Al films needs to be understood to optimize Al/CuO nanolaminates. To that end, the chemical mechanisms occurring during early stages of molecular CuO adsorption onto crystalline Al(111) surfaces are investigated using density functional theory (DFT) calculations, leading to the systematic determination of their reaction enthalpies and associated activation energies. We show that CuO undergoes dissociative chemisorption on Al(111) surfaces, whereby the Cu and O atoms tend to separate from each other. Both Cu and O atoms form islands with different properties. Copper islanding fosters Cu insertion (via surface site exchange mechanism) into the subsurface, while oxygen islands remain stable at the surface. Above a critical local oxygen coverage, aluminum atoms are extracted from the Al surface, leading to oxygen-aluminum intermixing and the formation of aluminum oxide (γ-alumina). For Cu and O co-deposition, copper promotes oxygen-aluminum interaction by oxygen segregation and separates the resulting oxide from the Al substrate by insertion into Al and stabilization below the oxide front, preventing full mixing of Al, Cu, and O species.
Fronstin, Paul
2011-09-01
LATEST CENSUS DATA: This Issue Brief provides historical data through 2010 on the number and percentage of nonelderly individuals with and without health insurance. Based on EBRI estimates from the U.S. Census Bureau's March 2011 Current Population Survey (CPS), it reflects 2010 data. It also discusses trends in coverage for the 1994-2010 period and highlights characteristics that typically indicate whether an individual is insured. HEALTH COVERAGE RATE CONTINUES TO DECREASE, UNINSURED INCREASE: The percentage of the nonelderly population (under age 65) with health insurance coverage decreased to 81.5 percent in 2010. Increases in health insurance coverage have been recorded in only three years since 1994, when 36.5 million nonelderly individuals were uninsured. The percentage of nonelderly individuals without health insurance coverage was 18.5 percent in 2010, up from 18.3 percent in 2009, and its highest level during the 1994-2010 period. EMPLOYMENT-BASED COVERAGE REMAINS DOMINANT SOURCE OF HEALTH COVERAGE, BUT CONTINUES TO ERODE: Employment-based health benefits remain the most common form of health coverage in the United States. In 2010, 58.7 percent of the nonelderly population had employment-based health benefits, down from 69.3 percent in 2000. SHIFTING COMPOSITION OF EMPLOYMENT-BASED COVERAGE: Between 2007 and 2010, the percentage of individuals under age 65 with employment-based coverage in their own name has dropped. In 2007, 54.2 percent had coverage in their own name. By 2010, it was down to 51.5 percent. Dependent coverage during this time period fell slightly from 17.5 percent to 17.1 percent, and increased slightly from 16.8 percent to 17.1 percent between 2009 and 2010. PUBLIC PROGRAM COVERAGE IS GROWING: Public program health coverage expanded as a percentage of the population in 2010, accounting for 21.6 percent of the nonelderly population. Enrollment in Medicaid and the State Children's Health Insurance Program increased, reaching a combined 45 million in 2010, and covering 16.9 percent of the nonelderly population, significantly above the 10.2 percent level of 1999. INDIVIDUAL COVERAGE STABLE: Individually purchased health coverage was unchanged in 2010 and has basically hovered in the 6-7 percent range since 1994. WHAT TO EXPECT IN 2011: 2010 is the most recent year for data on sources of health coverage. Unemployment in 2011 has been about 9 percent since the beginning of the year. While down from the 2010 average of 9.6 percent, it remains high and there is a continued threat of a double-dip recession increasing it even further. As a result, the nation is likely to see continued erosion of employment-based health benefits when the data for 2011 are released in 2012. Fewer working individuals translates into fewer individuals with access to health benefits in the work place, especially after COBRA subsidies have been exhausted.
The effect of Health Savings Accounts on group health insurance coverage.
Ye, Jinqi
2015-12-01
This paper presents new empirical evidence on the impact of tax subsidies for Health Savings Accounts (HSAs) on group insurance coverage. HSAs are tax-free health care expenditure savings accounts. Coupled with high deductible health insurance plans (HDHPs), they together represent new health insurance options. The tax advantage of HSAs expands the group health insurance market by making health care more affordable. Using individual level data from the Current Population Survey and exploiting policy variation by state and year from 2004 to 2012, I find that HSA tax subsidies increase small-group coverage by a statistically significant 2.5 percentage points, although not coverage in larger firms. Moreover, if the tax price of HSA contribution decreases by 10 cents, small-group insurance coverage increases by almost 2 percentage points. I also find that for older workers or less-educated workers, HSA subsidies are associated with 2-3 percentage point increase in their group insurance coverage. Copyright © 2015 Elsevier B.V. All rights reserved.
Walker, Neff; Yenokyan, Gayane; Friberg, Ingrid K; Bryce, Jennifer
2013-09-21
Urgent calls have been made for improved understanding of changes in coverage of maternal, newborn, and child health interventions, and their country-level determinants. We examined historical trends in coverage of interventions with proven effectiveness, and used them to project rates of child and neonatal mortality in 2035 in 74 Countdown to 2015 priority countries. We investigated coverage of all interventions for which evidence was available to suggest effective reductions in maternal and child mortality, for which indicators have been defined, and data have been obtained through household surveys. We reanalysed coverage data from 312 nationally-representative household surveys done between 1990 and 2011 in 69 countries, including 58 Countdown countries. We developed logistic Loess regression models for patterns of coverage change for each intervention, and used k-means cluster analysis to divide interventions into three groups with different historical patterns of coverage change. Within each intervention group, we examined performance of each country in achieving coverage gains. We constructed models that included baseline coverage, region, gross domestic product, conflict, and governance to examine country-specific annual percentage coverage change for each group of indicators. We used the Lives Saved Tool (LiST) to predict mortality rates of children younger than 5 years (henceforth, under 5) and in the neonatal period in 2035 for Countdown countries if trends in coverage continue unchanged (historical trends scenario) and if each country accelerates intervention coverage to the highest level achieved by a Countdown country with similar baseline coverage level (best performer scenario). Odds of coverage of three interventions (antimalarial treatment, skilled attendant at birth, and use of improved sanitation facilities) have decreased since 1990, with a mean annual decrease of 5·5% (SD 2·7%). Odds of coverage of four interventions--all related to the prevention of malaria--have increased rapidly, with a mean annual increase of 27·9% (7·3%). Odds of coverage of other interventions have slowly increased, with a mean annual increase of 5·3% (3·5%). Rates of coverage change varied widely across countries; we could not explain the differences by measures of gross domestic product, conflict, or governance. On the basis of LiST projections, we predicted that the number of Countdown countries with an under-5 mortality rate of fewer than 20 deaths per 1000 livebirths per year would increase from four (5%) of the 74 in 2010, to nine (12%) by 2035 under the historical trends scenario, and to 15 (20%) under the best performer scenario. The number of countries with neonatal mortality rates of fewer than 11 per 1000 livebirths per year would increase from three (4%) in 2010, to ten (14%) by 2035 under the historical trends scenario, and 67 (91%) under the best performer scenario. The number of under-5 deaths per year would decrease from an estimated 7·6 million in 2010, to 5·4 million (28% decrease) if historical trends continue, and to 2·3 million (71% decrease) under the best performer scenario. Substantial reductions in child deaths are possible, but only if intensified efforts to achieve intervention coverage are implemented successfully within each of the Countdown countries. The Bill & Melinda Gates Foundation. Copyright © 2013 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kuschel, Thomas; Keudell, Achim von
2010-05-15
Plasma deposition of aluminum oxide by reactive magnetron sputtering (RMS) using an aluminum target and argon and oxygen as working gases is an important technological process. The undesired oxidation of the target itself, however, causes the so-called target poisoning, which leads to strong hysteresis effects during RMS operation. The oxidation occurs by chemisorption of oxygen atoms and molecules with a simultaneous ion bombardment being present. This heterogenous surface reaction is studied in a quantified particle beam experiment employing beams of oxygen molecules and argon ions impinging onto an aluminum-coated quartz microbalance. The oxidation and/or sputtering rates are measured with thismore » microbalance and the resulting oxide layers are analyzed by x-ray photoelectron spectroscopy. The sticking coefficient of oxygen molecules is determined to 0.015 in the zero coverage limit. The sputtering yields of pure aluminum by argon ions are determined to 0.4, 0.62, and 0.8 at 200, 300, and 400 eV. The variation in the effective sticking coefficient and sputtering yield during the combined impact of argon ions and oxygen molecules is modeled with a set of rate equations. A good agreement is achieved if one postulates an ion-induced surface activation process, which facilitates oxygen chemisorption. This process may be identified with knock-on implantation of surface-bonded oxygen, with an electric-field-driven in-diffusion of oxygen or with an ion-enhanced surface activation process. Based on these fundamental processes, a robust set of balance equations is proposed to describe target poisoning effects in RMS.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Yan; Wei, Zhehao; Gao, Feng
2015-05-01
In this work, CeO2 nanocubes with controlled particle size and dominating (100) facets are synthesized as supports for VOx catalysts. Combined TEM, SEM, XRD, and Raman study reveals that the oxygen vacancy density of CeO2 supports can be tuned by tailoring the particle sizes without altering the dominating facets, where smaller particle sizes result in larger oxygen vacancy densities. At the same vanadium coverage, the VOx catalysts supported on small-sized CeO2 supports with higher oxygen defect densities exhibit promoted redox property and lower activation energy for methoxyl group decomposition, as evidenced by H2-TPR and methanol TPD study. These results furthermore » confirm that the presence of oxygen vacancies plays an important role in promoting the activity of VOx species in methanol oxidation. We gratefully acknowledge financial support from the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. Part of this work was conducted in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogram national laboratory operated for the DOE by Battelle.« less
Victora, Cesar G; Barros, Aluisio J D; Axelson, Henrik; Bhutta, Zulfiqar A; Chopra, Mickey; França, Giovanny V A; Kerber, Kate; Kirkwood, Betty R; Newby, Holly; Ronsmans, Carine; Boerma, J Ties
2012-09-29
Achievement of global health goals will require assessment of progress not only nationally but also for population subgroups. We aimed to assess how the magnitude of socioeconomic inequalities in health changes in relation to different rates of national progress in coverage of interventions for the health of mothers and children. We assessed coverage in low-income and middle-income countries for which two Demographic Health Surveys or Multiple Indicator Cluster Surveys were available. We calculated changes in overall coverage of skilled birth attendants, measles vaccination, and a composite coverage index, and examined coverage of a newly introduced intervention, use of insecticide-treated bednets by children. We stratified coverage data according to asset-based wealth quintiles, and calculated relative and absolute indices of inequality. We adjusted correlation analyses for time between surveys and baseline coverage levels. We included 35 countries with surveys done an average of 9·1 years apart. Pro-rich inequalities were very prevalent. We noted increased coverage of skilled birth attendants, measles vaccination, and the composite index in most countries from the first to the second survey, while inequalities were reduced. Rapid changes in overall coverage were associated with improved equity. These findings were not due to a capping effect associated with limited scope for improvement in rich households. For use of insecticide-treated bednets, coverage was high for the richest households, but countries making rapid progress did almost as well in reaching the poorest groups. National increases in coverage were primarily driven by how rapidly coverage increased in the poorest quintiles. Equity should be accounted for when planning the scaling up of interventions and assessing national progress. Bill & Melinda Gates Foundation; World Bank; Governments of Australia, Brazil, Canada, Norway, Sweden, and UK. Copyright © 2012 Elsevier Ltd. All rights reserved.
Rogers, Eleanor; Myatt, Mark; Woodhead, Sophie; Guerrero, Saul; Alvarez, Jose Luis
2015-01-01
Objective This paper reviews coverage data from programmes treating severe acute malnutrition (SAM) collected between July 2012 and June 2013. Design This is a descriptive study of coverage levels and barriers to coverage collected by coverage assessments of community-based SAM treatment programmes in 21 countries that were supported by the Coverage Monitoring Network. Data from 44 coverage assessments are reviewed. Setting These assessments analyse malnourished populations from 6 to 59 months old to understand the accessibility and coverage of services for treatment of acute malnutrition. The majority of assessments are from sub-Saharan Africa. Results Most of the programmes (33 of 44) failed to meet context-specific internationally agreed minimum standards for coverage. The mean level of estimated coverage achieved by the programmes in this analysis was 38.3%. The most frequently reported barriers to access were lack of awareness of malnutrition, lack of awareness of the programme, high opportunity costs, inter-programme interface problems, and previous rejection. Conclusions This study shows that coverage of CMAM is lower than previous analyses of early CTC programmes; therefore reducing programme impact. Barriers to access need to be addressed in order to start improving coverage by paying greater attention to certain activities such as community sensitisation. As barriers are interconnected focusing on specific activities, such as decentralising services to satellite sites, is likely to increase significantly utilisation of nutrition services. Programmes need to ensure that barriers are continuously monitored to ensure timely removal and increased coverage. PMID:26042827
Roughening of Pt nanoparticles induced by surface-oxide formation.
Zhu, Tianwei; Hensen, Emiel J M; van Santen, Rutger A; Tian, Na; Sun, Shi-Gang; Kaghazchi, Payam; Jacob, Timo
2013-02-21
Using density functional theory (DFT) and thermodynamic considerations we studied the equilibrium shape of Pt nanoparticles (NPs) under electrochemical conditions. We found that at very high oxygen coverage, obtained at high electrode potentials, the experimentally-observed tetrahexahedral (THH) NPs consist of high-index (520) faces. Since high-index surfaces often show higher (electro-)chemical activity in comparison to their close-packed counterparts, the THH NPs can be promising candidates for various (electro-)catalytic applications.
Changes in health insurance for US children and their parents: comparing 2003 to 2008.
Angier, Heather; DeVoe, Jennifer E; Tillotson, Carrie; Wallace, Lorraine
2013-01-01
Recent policy changes have affected access to health insurance for families in the United States. Private health insurance premiums have increased, and state Medicaid programs have cut back coverage for adults. Concurrently, the Children's Health Insurance Program has made public insurance available to more children. We aimed to better understand how child and parent health insurance coverage patterns may have changed as a result of these policies. We analyzed data from the nationally representative Medical Expenditure Panel Survey, comparing cohorts from 2003 and 2008. We assessed cross-sectional and full-year coverage patterns for child/parent pairs, stratified by income. We conducted chi-square tests to assess significant differences in coverage over time. Middle-income child/parent pairs had the most significant changes in their coverage patterns. For example, those with full-year health insurance coverage significantly decreased from 85.4% in 2003 to 80.6% in 2008. There was also an increase in uninsured middle-income child/parent pairs for the full year (5.6% in 2003 to 8.3% in 2008) and an increase in pairs who had a gap in coverage (9.7% in 2003 to 13.0% in 2008). The percentage of middle-income child/parent pairs who were lacking insurance, for part or all of the year, has risen, suggesting that these families may be caught between affording private coverage and being eligible for public coverage. Unless private coverage becomes more affordable, insurance instability among middle-income families may persist despite the passage of the Patient Protection and Affordable Care Act.
Reeder, Anthony I; Gray, Andrew R; Liley, J Ben; Scragg, Robert K R; McKenzie, Richard L; Stewart, Alistair W
2016-03-01
Clothing coverage is important for reducing skin cancer risk, but may also influence vitamin D sufficiency, so associated plausible predictors require investigation. Volunteers (18 to 85 years), with approximately equal numbers by sex and four ethnicity groups, were recruited in cities from two latitude bands: Auckland (36.9°S) and Dunedin (45.9°S). Baseline questionnaire, anthropometric and spectrophotometer skin colour data were collected and weather data obtained. Percent body coverage was calculated from eight week diary records. Potential independent predictors (unadjusted p < 0.25) were included in adjusted models. Participants (n = 506: Auckland n = 334, Dunedin n = 172; mean age 48.4 years) were 62.7% female and had a median body clothing coverage of 81.6% (IQR 9.3%). Dunedin was cooler, less windy and had lower UVI levels than Auckland. From the fully adjusted model, increased coverage occurred in non-summer months (despite adjusting for weather), among Dunedin residents and Asians (compared to Europeans), during the middle of the day, with a dose response effect observed for greater age. Reduced coverage was associated with Pacific ethnicity and greater time spent outdoors. Additionally, higher temperatures were associated with reduced coverage, whereas increased cloud cover and wind speed were associated with increased coverage. Although the only potentially modifiable factors associated with clothing coverage were the time period and time spent outdoors, knowledge of these and other associated factors is useful for the framing and targeting of health promotion messages to potentially influence clothing coverage, facilitate erythema avoidance and maintain vitamin D sufficiency.
Single-Isocenter Multiple-Target Stereotactic Radiosurgery: Risk of Compromised Coverage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roper, Justin, E-mail: justin.roper@emory.edu; Department of Biostatistics and Bioinformatics, Winship Cancer Institute of Emory University, Atlanta, Georgia; Chanyavanich, Vorakarn
2015-11-01
Purpose: To determine the dosimetric effects of rotational errors on target coverage using volumetric modulated arc therapy (VMAT) for multitarget stereotactic radiosurgery (SRS). Methods and Materials: This retrospective study included 50 SRS cases, each with 2 intracranial planning target volumes (PTVs). Both PTVs were planned for simultaneous treatment to 21 Gy using a single-isocenter, noncoplanar VMAT SRS technique. Rotational errors of 0.5°, 1.0°, and 2.0° were simulated about all axes. The dose to 95% of the PTV (D95) and the volume covered by 95% of the prescribed dose (V95) were evaluated using multivariate analysis to determine how PTV coverage was relatedmore » to PTV volume, PTV separation, and rotational error. Results: At 0.5° rotational error, D95 values and V95 coverage rates were ≥95% in all cases. For rotational errors of 1.0°, 7% of targets had D95 and V95 values <95%. Coverage worsened substantially when the rotational error increased to 2.0°: D95 and V95 values were >95% for only 63% of the targets. Multivariate analysis showed that PTV volume and distance to isocenter were strong predictors of target coverage. Conclusions: The effects of rotational errors on target coverage were studied across a broad range of SRS cases. In general, the risk of compromised coverage increased with decreasing target volume, increasing rotational error and increasing distance between targets. Multivariate regression models from this study may be used to quantify the dosimetric effects of rotational errors on target coverage given patient-specific input parameters of PTV volume and distance to isocenter.« less
Chernew, M; Frick, K; McLaughlin, C G
1997-10-01
To assess the degree to which premium reductions will increase the participation in employer-sponsored health plans by low-income workers who are employed in small businesses. Sample of workers in small business (25 or fewer employees) in seven metropolitan areas. The data were gathered as part of the Small Business Benefits Survey, a telephone survey of small business conducted between October 1992 and February 1993. Probit regressions were used to estimate the demand for health insurance coverage by low-income workers. Predictions based on these findings were made to assess the extent to which premium reductions might increase coverage rates. Workers included in the sample were selected, at random, from a randomly generated set of firms drawn from Dun and Bradstreet's DMI (Dun's Market Inclusion). The response rate was 81 percent. Participation in employer-sponsored plans is high when coverage is offered. However, even when coverage is offered to employees who have no other source of insurance, participation is not universal. Although premium reductions will increase participation in employer-sponsored plans, even large subsidies will not induce all workers to participate in employer-sponsored plans. For workers eligible to participate, subsidies as high as 75 percent of premiums are estimated to increase participation rates from 89.0 percent to 92.6 percent. For workers in firms that do not sponsor plans, similar subsidies are projected to achieve only modest increases in coverage above that which would be observed if the workers had access to plans at unsubsidized, group market rates. Policies that rely on voluntary purchase of coverage to reduce the number of uninsured will have only modest success.
Look, Kevin A; Arora, Prachi
2016-01-01
The US Affordable Care Act (ACA) extended the age of eligibility for young adults to remain on their parents' health insurance plans in order to address the disproportionate number of uninsured young adults in the United States. Effective September 23, 2010, the ACA has required all private health insurance plans to cover dependents until the age of 26. However, it is unknown whether the ACA dependent coverage expansion had an impact on prescription drug insurance or the use of prescription drugs. To evaluate short-term changes in prescription health insurance coverage, prescription drug insurance coverage, prescription drug use, and prescription drug expenditures following implementation of the ACA young adult insurance expansion using national data from 2009 and 2011. Full-year health insurance coverage increased 4.9 percentage points during the study period, which was mainly due to increases in private health insurance among middle- and high-income young adults. In contrast, full-year prescription drug insurance coverage increased 5.5 percentage points and was primarily concentrated among high-income young adults. Although no significant short-term changes in overall prescription drug use were observed, a 30% decrease in out-of-pocket expenditures was seen among young adults. While the main goal of the ACA's young adult insurance expansion was to increase health insurance coverage among young adults, it also had the unintended positive effect of increasing coverage for prescription drug insurance. Additionally, young adults experienced substantial decreases in out-of-pocket spending for prescription drugs. It is important for evaluations of health care policies to assess both intended and unintended outcomes to better understand the implications for the broader health system. Copyright © 2015 Elsevier Inc. All rights reserved.
Goel, Sonu; Dogra, Vishal; Gupta, Satish Kumar; Lakshmi, P Vm; Varkey, Sherin; Pradhan, Narottam; Krishna, Gopal; Kumar, Rajesh
2012-02-01
In Bihar State, proportion of fully immunized children was only 19% ;in Coverage Evaluation Survey of 2005. In October 2007, a special campaign called Muskaan Ek Abhiyan (The Smile Campaign) was launched under National Rural Health Mission to give a fillip to the immunization program. To evaluate improvement in the performance and coverage of the Routine Immunization Program consequent to the launch of Muskaan Ek Abhiyan The main strategies of the Muskaan campaign were reviewing and strengthening immunization micro-plans, enhanced inter-sectoral coordination between the Departments of Health, and Women and Child Development, increased involvement of women groups in awareness generation, enhanced political commitment and budgetary support, strengthening of monitoring and supervision mechanisms, and provision of performance based incentive to service providers. Immunization Coverage Evaluation Surveys conducted in various states of India during 2005 and 2009 were used for evaluation of the effect of Muskaan campaign by measuring the increase in immunization coverage in Bihar in comparison to other Empowered Action Group (EAG) states using the difference-in-difference method. Interviews of the key stakeholders were also done to substantiate the findings. The proportion of fully immunized 12-23 month old children in Bihar has increased significantly from 19% ;in 2005 to 49% ;in 2009. The coverage of BCG also increased significantly from 52.8% to 82.3%, DPT-3 from 36.5 to 59.3%, OPV-3 from 27.1% ;to 61.6% ;and measles from 28.4 to 58.2%. In comparison to other states, the coverage of fully immunized children increased significantly from 16 to 26% ;in Bihar. There was a marked improvement in immunization coverage after the launch of the Campaign in Bihar. Therefore, best practices of the Campaign may be replicated in other areas where full immunization coverage is low.
Zhang, Yuting; Baik, Seo Hyon; Zhou, Lei; Reynolds, Charles F; Lave, Judith R
2012-07-01
Maintenance antidepressant pharmacotherapy in late life prevents recurrent episodes of major depression. The coverage gap in Medicare Part D could increase the likelihood of reducing appropriate use of antidepressants, thereby exposing older adults to an increased risk for relapse of depressive episodes. To determine whether (1) beneficiaries reduce antidepressant use in the gap, (2) the reduction in antidepressant use is similar to the reduction in heart failure medications and antidiabetics, (3) the provision of generic coverage reduces the risk of reduction of medication use, and (4) medical spending increases in the gap. Observational before-after study with a comparison group design. A 5% random sample of US Medicare beneficiaries 65 years or older with depression (n = 65,223) enrolled in stand-alone Part D plans in 2007. Antidepressant pharmacotherapy, physician, outpatient, and inpatient spending. Being in the gap was associated with comparable reductions in the use of antidepressants, heart failure medications, and antidiabetics. Relative to the comparison group (those who had full coverage in the gap because of Medicare coverage or low-income subsidies), the no-coverage group reduced their monthly antidepressant prescriptions by 12.1% (95% CI, 9.9%-14.3%) from the pregap level, whereas they reduced use of heart failure drugs and antidiabetics by 12.9% and 13.4%, respectively. Those with generic drug coverage in the gap reduced their monthly antidepressant prescriptions by 6.9% (95% CI, 4.8%-9.1%); this decrease was entirely attributable to the reduction in the use of brand-name antidepressants. Medicare spending on medical care did not increase for either group relative to the comparison group. The Medicare Part D coverage gap was associated with modest reductions in the use of antidepressants. Those with generic coverage reduced their use of brand-name drugs and did not switch from brand-name to generic drugs. The reduction in antidepressant use was not associated with an increase in nondrug medical spending.
Platinum Monolayer Electrocatalysts for Oxygen Reduction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vukmirovic, Miomir B.; Zhang, Junliang; Sasaki, Kotaro
2007-01-20
The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. We have synthesized a new class of electrocatalysts for the oxygen reduction reaction, consisting of a monolayer of Pt or mixed monolayer of Pt and another late transition metal (Au, Pd, Ir, Ru, Rh, Re or Os) deposited on a Pd(1 1 1) single crystal or on carbon-supported Pd nanoparticles. Several of these electrocatalysts exhibited very high activity, amounting tomore » 20-fold increase in a Pt mass activity, compared with conventional all-Pt electrocatalysts. Their superior activity reflects a low OH coverage on Pt, caused by the lateral repulsion between the OH adsorbed on Pt and the OH or O adsorbed on neighboring, other than Pt, late transition metal atoms. The origin of this effect was identified through a combination of experimental and theoretical methods, employing electrochemical techniques, X-ray absorption spectroscopy, and periodic, self-consistent density functional theory calculations. This new class of electrocatalysts promises to alleviate some major problems of existing fuel cell technology by simultaneously decreasing materials cost and enhancing performance.« less
Kirzinger, Whitney K; Cohen, Robin A; Gindi, Renee M
2013-12-01
Data from the National Health Interview Survey, 2008-2012. The percentage of young adults with private health insurance coverage increased from the last 6 months of 2010 through the last 6 months of 2012 (52.0% to 57.9%). Except for an increase in the first 6 months of 2011, the percentage of privately insured young adults who had a gap in coverage during the past 12 months decreased from the first 6 months of 2008 through the last 6 months of 2012 (10.5% to 7.8%). The percentage of privately insured young adults with coverage in their own name decreased from 40.8% in the last 6 months of 2010 to 27.2% in the last 6 months of 2012. The percentage of privately insured young adults with employer-sponsored health insurance increased from the last 6 months of 2010 to the last 6 months of 2012 (85.6% to 92.5%). Young adults often experience instability with regard to work, school, residential status, and financial independence. This could contribute to a lack of or gaps in insurance coverage (1,2). In September 2010, the Affordable Care Act (ACA) extended dependent health coverage to young adults up to age 26. This provision was expected to lead to increases in private coverage for young adults aged 19-25 when they became eligible for coverage through their parents' employment (3,4). This report provides estimates describing the previous insurance status and sources of coverage among privately insured young adults aged 19-25, using data from the 2008-2012 National Health Interview Survey (NHIS). Comparisons are made with adults aged 26-34, the most similar age group that was not affected by the ACA provision. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.
Sharma, Monisha; Seoud, Muhieddine; Kim, Jane J
2017-01-23
Most cervical cancer (CC) cases in Lebanon are detected at later stages and associated with high mortality. There is no national organized CC screening program so screening is opportunistic and limited to women who can pay out-of-pocket. Therefore, a small percentage of women receive repeated screenings while most are under-or never screened. We evaluated the cost-effectiveness of increasing screening coverage and extending intervals. We used an individual-based Monte Carlo model simulating HPV and CC natural history and screening. We calibrated the model to epidemiological data from Lebanon, including CC incidence and HPV type distribution. We evaluated cytology and HPV DNA screening for women aged 25-65years, varying coverage from 20 to 70% and frequency from 1 to 5years. At 20% coverage, annual cytologic screening reduced lifetime CC risk by 14% and had an incremental cost-effectiveness ratio of I$80,670/year of life saved (YLS), far exceeding Lebanon's gross domestic product (GDP) per capita (I$17,460), a commonly cited cost-effectiveness threshold. By comparison, increasing cytologic screening coverage to 50% and extending screening intervals to 3 and 5years provided greater CC reduction (26.1% and 21.4, respectively) at lower costs compared to 20% coverage with annual screening. Screening every 5years with HPV DNA testing at 50% coverage provided greater CC reductions than cytology at the same frequency (23.4%) and was cost-effective assuming a cost of I$18 per HPV test administered (I$12,210/YLS); HPV DNA testing every 4years at 50% coverage was also cost-effective at the same cost per test (I$16,340). Increasing coverage of annual cytology was not found to be cost-effective. Current practice of repeated cytology in a small percentage of women is inefficient. Increasing coverage to 50% with extended screening intervals provides greater health benefits at a reasonable cost and can more equitably distribute health gains. Novel HPV DNA strategies offer greater CC reductions and may be more cost-effective than cytology. Copyright © 2016 Elsevier Ltd. All rights reserved.
Premium subsidies, the mandate, and Medicaid expansion: Coverage effects of the Affordable Care Act.
Frean, Molly; Gruber, Jonathan; Sommers, Benjamin D
2017-05-01
Using premium subsidies for private coverage, an individual mandate, and Medicaid expansion, the Affordable Care Act (ACA) has increased insurance coverage. We provide the first comprehensive assessment of these provisions' effects, using the 2012-2015 American Community Survey and a triple-difference estimation strategy that exploits variation by income, geography, and time. Overall, our model explains 60% of the coverage gains in 2014-2015. We find that coverage was moderately responsive to price subsidies, with larger gains in state-based insurance exchanges than the federal exchange. The individual mandate's exemptions and penalties had little impact on coverage rates. The law increased Medicaid among individuals gaining eligibility under the ACA and among previously-eligible populations ("woodwork effect") even in non-expansion states, with no resulting reductions in private insurance. Overall, exchange premium subsidies produced 40% of the coverage gains explained by our ACA policy measures, and Medicaid the other 60%, of which 1/2 occurred among previously-eligible individuals. Copyright © 2017 Elsevier B.V. All rights reserved.
Assessing Measurement Error in Medicare Coverage From the National Health Interview Survey
Gindi, Renee; Cohen, Robin A.
2012-01-01
Objectives Using linked administrative data, to validate Medicare coverage estimates among adults aged 65 or older from the National Health Interview Survey (NHIS), and to assess the impact of a recently added Medicare probe question on the validity of these estimates. Data sources Linked 2005 NHIS and Master Beneficiary Record and Payment History Update System files from the Social Security Administration (SSA). Study design We compared Medicare coverage reported on NHIS with “benchmark” benefit records from SSA. Principal findings With the addition of the probe question, more reports of coverage were captured, and the agreement between the NHIS-reported coverage and SSA records increased from 88% to 95%. Few additional overreports were observed. Conclusions Increased accuracy of the Medicare coverage status of NHIS participants was achieved with the Medicare probe question. Though some misclassification remains, data users interested in Medicare coverage as an outcome or correlate can use this survey measure with confidence. PMID:24800138
Long-term reduction in poly(dimethylsiloxane) surface hydrophobicity via cold-plasma treatments.
Larson, B J; Gillmor, S D; Braun, J M; Cruz-Barba, L E; Savage, D E; Denes, F S; Lagally, M G
2013-10-22
Poly(dimethylsiloxane), PDMS, a versatile elastomer, is the polymer of choice for microfluidic systems. It is inexpensive, relatively easy to pattern, and permeable to oxygen. Unmodified PDMS is highly hydrophobic. It is typically exposed to an oxygen plasma to reduce this hydrophobicity. Unfortunately, the PDMS surface soon returns to its original hydrophobic state. We present two alternative plasma treatments that yield long-term modification of the wetting properties of a PDMS surface. An oxygen plasma pretreatment followed by exposure to a SiCl4 plasma and an oxygen-CCl4 mixture plasma both cause a permanent reduction in the hydrophobicity of the PDMS surface. We investigate the properties of the plasma-treated surfaces with X-ray photoelectron spectroscopy (XPS) and contact angle measurements. We propose that the plasma treated PDMS surface is a dynamic mosaic of high- and low-contact-angle functionalities. The SiCl4 and CCl4 plasmas attach polar groups that block coverage of the surface by low-molecular-weight groups that exist in PDMS. We describe an application that benefits from these new plasma treatments, the use of a PDMS stencil to form dense arrays of DNA on a surface.
Pezzoli, Lorenzo; Pineda, Silvia; Halkyer, Percy; Crespo, Gladys; Andrews, Nick; Ronveaux, Olivier
2009-03-01
To estimate the yellow fever (YF) vaccine coverage for the endemic and non-endemic areas of Bolivia and to determine whether selected districts had acceptable levels of coverage (>70%). We conducted two surveys of 600 individuals (25 x 12 clusters) to estimate coverage in the endemic and non-endemic areas. We assessed 11 districts using lot quality assurance sampling (LQAS). The lot (district) sample was 35 individuals with six as decision value (alpha error 6% if true coverage 70%; beta error 6% if true coverage 90%). To increase feasibility, we divided the lots into five clusters of seven individuals; to investigate the effect of clustering, we calculated alpha and beta by conducting simulations where each cluster's true coverage was sampled from a normal distribution with a mean of 70% or 90% and standard deviations of 5% or 10%. Estimated coverage was 84.3% (95% CI: 78.9-89.7) in endemic areas, 86.8% (82.5-91.0) in non-endemic and 86.0% (82.8-89.1) nationally. LQAS showed that four lots had unacceptable coverage levels. In six lots, results were inconsistent with the estimated administrative coverage. The simulations suggested that the effect of clustering the lots is unlikely to have significantly increased the risk of making incorrect accept/reject decisions. Estimated YF coverage was high. Discrepancies between administrative coverage and LQAS results may be due to incorrect population data. Even allowing for clustering in LQAS, the statistical errors would remain low. Catch-up campaigns are recommended in districts with unacceptable coverage.
Palmisano, Donald J; Emmons, David W; Wozniak, Gregory D
2004-05-12
Recent reports showing an increase in the number of uninsured individuals in the United States have given heightened attention to increasing health insurance coverage. The American Medical Association (AMA) has proposed a system of tax credits for the purchase of individually owned health insurance and enhancements to individual and group health insurance markets as a means of expanding coverage. Individually owned insurance would enable people to maintain coverage without disruption to existing patient-physician relationships, regardless of changes in employers or in work status. The AMA's plan would empower individuals to choose their health plan and give patients and their physicians more control over health care choices. Employers could continue to offer employment-based coverage, but employees would not be limited to the health plans offered by their employer. With a tax credit large enough to make coverage affordable and the ability to choose their own coverage, consumers would dramatically transform the individual and group health insurance markets. Health insurers would respond to the demands of individual consumers and be more cautious about increasing premiums. Insurers would also tailor benefit packages and develop new forms of coverage to better match the preferences of individuals and families. The AMA supports the development of new health insurance markets through legislative and regulatory changes to foster a wider array of high-quality, affordable plans.
Impact of Coverage-Dependent Marginal Costs on Optimal HPV Vaccination Strategies
Ryser, Marc D.; McGoff, Kevin; Herzog, David P.; Sivakoff, David J.; Myers, Evan R.
2015-01-01
The effectiveness of vaccinating males against the human papillomavirus (HPV) remains a controversial subject. Many existing studies conclude that increasing female coverage is more effective than diverting resources into male vaccination. Recently, several empirical studies on HPV immunization have been published, providing evidence of the fact that marginal vaccination costs increase with coverage. In this study, we use a stochastic agent-based modeling framework to revisit the male vaccination debate in light of these new findings. Within this framework, we assess the impact of coverage-dependent marginal costs of vaccine distribution on optimal immunization strategies against HPV. Focusing on the two scenarios of ongoing and new vaccination programs, we analyze different resource allocation policies and their effects on overall disease burden. Our results suggest that if the costs associated with vaccinating males are relatively close to those associated with vaccinating females, then coverage-dependent, increasing marginal costs may favor vaccination strategies that entail immunization of both genders. In particular, this study emphasizes the necessity for further empirical research on the nature of coverage-dependent vaccination costs. PMID:25979280
Impact of Medicare on the Use of Medical Services by Disabled Beneficiaries, 1972-1974
Deacon, Ronald W.
1979-01-01
The extension of Medicare coverage in 1973 to disabled persons receiving cash benefits under the Social Security Act provided an opportunity to examine the impact of health insurance coverage on utilization and expenses for Part B services. Data on medical services used both before and after coverage, collected through the Current Medicare Survey, were analyzed. Results indicate that access to care (as measured by the number of persons using services) increased slightly, while the rate of use did not. The large increase in the number of persons eligible for Medicare reflected the large increase in the number of cash beneficiaries. Significant increases also were found in the amount charged for medical services. The absence of large increases in access and service use may be attributed, in part, to the already existing source of third party payment available to disabled cash beneficiaries in 1972, before Medicare coverage. PMID:10316939
A brief review of vaccination coverage in immunization registries.
Goldstein, Neal D; Maiese, Brett A
2011-01-01
Immunization registries are effective electronic tools for assessing vaccination coverage, but are only as good as the information reported to them. This review summarizes studies through August 2010 on vaccination coverage in registries and identifies key characteristics of successful registries. Based on the current state of registries, paper-based charts combined with electronic registry reporting provide the most cohesive picture of coverage. To ultimately supplant paper charts, registries must exhibit increased coverage and participation.
An Evaluation of Voluntary Varicella Vaccination Coverage in Zhejiang Province, East China.
Hu, Yu; Chen, Yaping; Zhang, Bing; Li, Qian
2016-06-03
In 2014 a 2-doses varicella vaccine (VarV) schedule was recommended by the Zhejiang Provincial Center for Disease Control and Prevention. We aimed to assess the coverage of the 1st dose of VarV (VarV₁) and the 2nd dose of VarV (VarV₂) among children aged 2-6 years through the Zhejiang Provincial Immunization Information System (ZJIIS) and to explore the determinants associated with the VarV coverage. Children aged 2-6 years (born from 1 January 2009 to 31 December 2013) registered in ZJIIS were enrolled. Anonymized individual records of target children were extracted from the ZJIIS database on 1 January 2016, including their VarV and (measles-containing vaccine) MCV vaccination information. The VarV₁ and VarV₂ coverage rates were evaluated for each birth cohorts. The coverage of VarV also was estimated among strata defined by cities, gender and immigration status. We also evaluated the difference in coverage between VarV and MCV. A total of 3,028,222 children aged 2-6 years were enrolled. The coverage of VarV₁ ranged from 84.8% to 87.9% in the 2009-2013 birth cohorts, while the coverage of VarV₂ increased from 31.8% for the 2009 birth cohort to 48.7% for the 2011 birth cohort. Higher coverage rates for both VarV₁ and VarV₂ were observed among resident children in relevant birth cohorts. The coverage rates of VarV₁ and VarV₂ were lower than those for the 1st and 2nd dose of MCV, which were above 95%. The proportion of children who were vaccinated with VarV₁ at the recommended age increased from 34.6% for the 2009 birth cohort to 75.2% for the 2013 birth cohort, while the proportion of children who were vaccinated with VarV₂ at the recommended age increased from 19.7% for the 2009 birth cohort to 48.7% for the 2011 birth cohort. Our study showed a rapid increasing VarV₂ coverage of children, indicating a growing acceptance of the 2-doses VarV schedule among children's caregivers and physicians after the new recommendation released. We highlighted the necessity for a 2-doses VarV vaccination school-entry requirement to achieve the high coverage of >90% and to eliminate disparities in coverage among sub-populations. We also recommended continuous monitoring of the VarV coverage via ZJIIS over time.
Lee, Bruce Y; Bartsch, Sarah M; Stone, Nathan T B; Zhang, Shufang; Brown, Shawn T; Chatterjee, Chandrani; DePasse, Jay V; Zenkov, Eli; Briët, Olivier J T; Mendis, Chandana; Viisainen, Kirsi; Candrinho, Baltazar; Colborn, James
2017-06-01
AbstractMalaria-endemic countries have to decide how much of their limited resources for vector control to allocate toward implementing long-lasting insecticidal nets (LLINs) versus indoor residual spraying (IRS). To help the Mozambique Ministry of Health use an evidence-based approach to determine funding allocation toward various malaria control strategies, the Global Fund convened the Mozambique Modeling Working Group which then used JANUS, a software platform that includes integrated computational economic, operational, and clinical outcome models that can link with different transmission models (in this case, OpenMalaria) to determine the economic value of vector control strategies. Any increase in LLINs (from 80% baseline coverage) or IRS (from 80% baseline coverage) would be cost-effective (incremental cost-effectiveness ratios ≤ $114/disability-adjusted life year averted). However, LLIN coverage increases tend to be more cost-effective than similar IRS coverage increases, except where both pyrethroid resistance is high and LLIN usage is low. In high-transmission northern regions, increasing LLIN coverage would be more cost-effective than increasing IRS coverage. In medium-transmission central regions, changing from LLINs to IRS would be more costly and less effective. In low-transmission southern regions, LLINs were more costly and less effective than IRS, due to low LLIN usage. In regions where LLINs are more cost-effective than IRS, it is worth considering prioritizing LLIN coverage and use. However, IRS may have an important role in insecticide resistance management and epidemic control. Malaria intervention campaigns are not a one-size-fits-all solution, and tailored approaches are necessary to account for the heterogeneity of malaria epidemiology.
Decker, Sandra L; Lipton, Brandy J
2015-12-01
This article examines the effect of Medicaid adult dental coverage on use of dental care and dental health outcomes using state-level variation in dental coverage during 2000-2012. Our findings imply that dental coverage is associated with an increase in the likelihood of a recent dental visit, with the size of the effect increasing with Medicaid payment rates to dentists, and a reduction in the likelihood of untreated dental caries. We are among the first to detect an effect of Medicaid coverage on a clinical health outcome other than mortality. These findings may have implications for states expanding Medicaid coverage to adults with incomes of up to 138% of the federal poverty threshold under the Affordable Care Act as most of these states offer an adult dental benefit. Copyright © 2015 Elsevier B.V. All rights reserved.
Examination of media coverage of increasing the speed limit to 65 mph
DOT National Transportation Integrated Search
1988-09-01
Heightened newspaper and television coverage of the proposed 65 mph limit may have encouraged increased travel speeds which in turn could have produced an increase in fatalities prior to passage of the national legislation. To pursue this further, NH...
Chen, Yen-Yuan; Chen, Likwang; Kao, Yu-Hui; Chu, Tzong-Shinn; Huang, Tien-Shang; Ko, Wen-Je
2014-08-01
Extra-corporeal membrane oxygenation has been introduced to clinical practice for several decades. It is unclear how internet and newspapers portray the use of extra-corporeal membrane oxygenation. This study were: (1) to quantify the coverage of extra-corporeal membrane oxygenation use in newspapers and on the Internet; (2) to describe the characteristics of extra-corporeal membrane oxygenation users presented in newspaper articles and the Internet web pages in comparison with those shown in extra-corporeal membrane oxygenation studies in Taiwan; and (3) to examine the survival rates of extra-corporeal membrane oxygenation users presented in newspaper articles and the Internet web pages in comparison with those in Taiwan and in the Extracorporeal Life Support Registry Report International Summary for January 2014. All issues of Taiwan's four major newspapers from 2006 to 2010 were reviewed. In October 2011, a search of Internet web pages was performed based on the subjects of "yeh-ko-mo" (extra-corporeal membrane oxygenation in Traditional Chinese), "ECMO", and "extra-corporeal membrane oxygenation." All the Internet web pages and newspaper articles recounting the use of extra-corporeal membrane oxygenation were reviewed. The information, such as patient characteristic and the status at hospital discharge, was collected. The survival rate of extra-corporeal membrane oxygenation use shown on the Internet (83.97%) was significantly higher than all the survival rates reported in Taiwan's literature (p < .01) and in the Extracorporeal Life Support Registry Report International Summary for January 2014 (p < .01). In addition, the survival rate of extra-corporeal membrane oxygenation use shown in newspapers (61.54%) was significantly higher than the average survival rate (43%) reported in Taiwan's literature, the pediatric average survival rate (51%), and the adult average survival rate (47%) in the Extracorporeal Life Support Registry Report International Summary for January 2014. Internet and newspapers both showed over-optimistic survival to hospital discharge for patients sustained by extra-corporeal membrane oxygenation. Internet was more likely to provide optimistic information for aggressive life-supporting treatments such as extra-corporeal membrane oxygenation than newspapers as indicated by survival to hospital discharge.
State of equity: childhood immunization in the World Health Organization African Region.
Casey, Rebecca Mary; Hampton, Lee McCalla; Anya, Blanche-Philomene Melanga; Gacic-Dobo, Marta; Diallo, Mamadou Saliou; Wallace, Aaron Stuart
2017-01-01
In 2010, the Global Vaccine Action Plan called on all countries to reach and sustain 90% national coverage and 80% coverage in all districts for the third dose of diphtheria-tetanus-pertussis vaccine (DTP3) by 2015 and for all vaccines in national immunization schedules by 2020. The aims of this study are to analyze recent trends in national vaccination coverage in the World Health Organization African Region andto assess how these trends differ by country income category. We compared national vaccination coverage estimates for DTP3 and the first dose of measles-containing vaccine (MCV) obtained from the World Health Organization (WHO)/United Nations Children's Fund (UNICEF) joint estimates of national immunization coverage for all African Region countries. Using United Nations (UN) population estimates of surviving infants and country income category for the corresponding year, we calculated population-weighted average vaccination coverage by country income category (i.e., low, lower middle, and upper middle-income) for the years 2000, 2005, 2010 and 2015. DTP3 coverage in the African Region increased from 52% in 2000 to 76% in 2015,and MCV1 coverage increased from 53% to 74% during the same period, but with considerable differences among countries. Thirty-six African Region countries were low income in 2000 with an average DTP3 coverage of 50% while 26 were low income in 2015 with an average coverage of 80%. Five countries were lower middle-income in 2000 with an average DTP3 coverage of 84% while 12 were lower middle-income in 2015 with an average coverage of 69%. Five countries were upper middle-income in 2000 with an average DTP3 coverage of 73% and eight were upper middle-income in 2015 with an average coverage of 76%. Disparities in vaccination coverage by country persist in the African Region, with countries that were lower middle-income having the lowest coverage on average in 2015. Monitoring and addressing these disparities is essential for meeting global immunization targets.
Li, Pengxiang; McElligott, Sean; Bergquist, Henry; Schwartz, J Sanford; Doshi, Jalpa A
2012-06-05
Prior studies of the Medicare Part D coverage gap are limited in generalizability and scope. To determine the effect of the coverage gap on drugs used for asymptomatic (antihypertensive and lipid-lowering drugs) and symptomatic (pain relievers, acid suppressants, and antidepressants) conditions in elderly patients with hypertension and hyperlipidemia. Quasi-experimental study using pre-post design and contemporaneous control group. Medicare claims files from 2005 and 2006 for 5% random sample of Medicare beneficiaries. Part D plan enrollees with hypertension or hyperlipidemia aged 65 years or older who had no coverage, generic-only coverage, or both brand-name and generic coverage during the gap in 2006. Patients who were fully eligible for the low-income subsidy served as the control group. Monthly 30-day supply prescriptions available, medication adherence, and continuous medication gaps of 30 days or more for antihypertensive or lipid-lowering drugs; monthly 30-day supply prescriptions available for pain relievers, acid suppressants, or antidepressants before and after coverage gap entry. Patients with no gap coverage had a decrease in monthly antihypertensive and lipid-lowering drug prescriptions during the coverage gap. Nonadherence also increased in this group (antihypertensives: odds ratio [OR], 1.60 [95% CI, 1.50 to 1.71]; lipid-lowering drugs: OR, 1.59 [CI, 1.50 to 1.68]). The proportion of patients with no gap coverage who had continuous medication gaps in lipid-lowering medication use and antihypertensive use increased by an absolute 7.3% (OR, 1.38 [CI, 1.29 to 1.46]) and 3.2% (OR, 1.35 [CI, 1.25 to 1.45]), respectively, because of the coverage gap. Decreases in use were smaller for pain relievers and antidepressants and larger for acid suppressants in patients with no gap coverage. Patients with generic-only coverage had decreased use of cardiovascular medications but no change in use of drugs for symptomatic conditions. No measures changed in the brand-name and generic coverage groups. Results of sensitivity analyses were consistent with the main findings. Because this study was nonrandomized, unobserved differences may still exist between study groups. The Part D coverage gap was associated with decreased use of medications for hypertension and hyperlipidemia in patients with no gap coverage and generic-only gap coverage. The proposed phasing out of the gap by 2020 will benefit such patients; however, use of low-value medications may also increase. Penn-Pfizer Alliance and American Heart Association.
Media advocacy, tobacco control policy change and teen smoking in Florida
Niederdeppe, Jeff; Farrelly, Matthew C; Wenter, Dana
2007-01-01
Objective To assess whether media advocacy activities implemented by the Florida Tobacco Control Program contributed to increased news coverage, policy changes and reductions in youth smoking. Methods A content analysis of news coverage appearing in Florida newspapers between 22 April 1998 and 31 December 2001 was conducted, and patterns of coverage before and after the implementation of media advocacy efforts to promote tobacco product placement ordinances were compared. Event history analysis was used to assess whether news coverage increased the probability of enacting these ordinances in 23 of 67 Florida counties and ordinary least square (OLS) regression was used to gauge the effect of these policies on changes in youth smoking prevalence. Results The volume of programme‐related news coverage decreased after the onset of media advocacy efforts, but the ratio of coverage about Students Working Against Tobacco (the Florida Tobacco Control Program's youth advocacy organisation) relative to other topics increased. News coverage contributed to the passage of tobacco product placement ordinances in Florida counties, but these ordinances did not lead to reduced youth smoking. Conclusion This study adds to the growing literature supporting the use of media advocacy as a tool to change health‐related policies. However, results suggest caution in choosing policy goals that may or may not influence health behaviour. PMID:17297073
Assaad, Ramia; Rebeschini, Arianna; Hamadeh, Randa
2016-01-01
Introduction With the high proportion of refugee population throughout Lebanon and continuous population movement, it is sensible to believe that, in particular vulnerable areas, vaccination coverage may not be at an optimal level. Therefore, we assessed the vaccination coverage in children under 5 in a district of the Akkar governorate before and after a vaccination campaign. During the vaccination campaign, conducted in August 2015, 2,509 children were vaccinated. Materials and Methods We conducted a pre- and post-vaccination campaign coverage surveys adapting the WHO EPI cluster survey to the Lebanese MoPH vaccination calendar. Percentages of coverage for each dose of each vaccine were calculated for both surveys. Factors associated with complete vaccination were explored. Results Comparing the pre- with the post-campaign surveys, coverage for polio vaccine increased from 51.9% to 84.3%, for Pentavalent from 49.0% to 71.9%, for MMR from 36.2% to 61.0%, while the percentage of children with fully updated vaccination calendar increased from 32.9% to 53.8%. While Lebanese children were found to be better covered for some antigens compared to Syrians at the first survey, this difference disappeared at the post-campaign survey. Awareness and logistic obstacles were the primary reported causes of not complete vaccination in both surveys. Discussion Vaccination campaigns remain a quick and effective approach to increase vaccination coverage in crisis-affected areas. However, campaigns cannot be considered as a replacement of routine vaccination services to maintain a good level of coverage. PMID:27992470
Irving, Stephanie A; Groom, Holly C; Stokley, Shannon; McNeil, Michael M; Gee, Julianne; Smith, Ning; Naleway, Allison L
2018-03-01
Human papillomavirus (HPV) vaccination has been recommended in the United States for female and male adolescents since 2006 and 2011, respectively. Coverage rates are lower than those for other adolescent vaccines. The objective of this study was to evaluate an assessment and feedback intervention designed to increase HPV vaccination coverage and quantify missed opportunities for HPV vaccine initiation at preventive care visits. We examined changes in HPV vaccination coverage and missed opportunities within the adolescent (11-17 years) population at 9 Oregon-based Kaiser Permanente Northwest outpatient clinics after an assessment and feedback intervention. Quarterly coverage rates were calculated for the adolescent populations at the clinics, according to age group (11-12 and 13-17 years), sex, and department (Pediatrics and Family Medicine). Comparison coverage assessments were calculated at 3 nonintervention (control) clinics. Missed opportunities for HPV vaccine initiation, defined as preventive care visits in which a patient eligible for HPV dose 1 remained unvaccinated, were examined according to sex and age group. An average of 29,021 adolescents were included in coverage assessments. Before the intervention, 1-dose and 3-dose quarterly coverage rates were increasing at intervention as well as at control clinics in both age groups. Postimplementation quarterly trends in 1-dose or 3-dose coverage did not differ significantly between intervention and control clinics for either age group. One-dose coverage rates among adolescents with Pediatrics providers were significantly higher than those with Family Medicine providers (56% vs 41% for 11- to 12-year-old and 82% vs 69% for 13- to 17-year-old girls; 55% vs 40% for 11- to 12-year-old and 78% vs 62% for 13- to 17-year-old boys). No significant differences in HPV vaccine coverage were identified at intervention clinics. However, coverage rates were increasing before the start of the intervention and might have been influenced by ongoing health system best practices. HPV vaccine coverage rates varied significantly according to department, which could allow for targeted improvement opportunities. Copyright © 2017 Academic Pediatric Association. All rights reserved.
ERIC Educational Resources Information Center
Kenney, Genevieve M.; Dorn, Stan
2009-01-01
Moving toward universal coverage has the potential to increase access to care and improve the health and well-being of uninsured children and adults. The effects of health care reform on the more than 25 million children who currently have coverage under Medicaid or the Children's Health Insurance Program (CHIP) are less clear. Increased parental…
Lewis, Rayleen M; Markowitz, Lauri E
2018-05-03
Human papillomavirus (HPV) vaccination has been routinely recommended at age 11-12 years in the United States for females since 2006 and males since 2011. Coverage can be estimated using self/parent-reported HPV vaccination collected in the National Health and Nutrition Examination Survey (NHANES) for a wider age range than other national surveys. We assessed vaccination coverage in 2015-2016, temporal trends by age, and the validity of self/parent-reported vaccination status. Participants aged 9-59 years completed an interview collecting demographic and vaccination information. Weighted coverage was estimated for two-year NHANES cycles by age group for 2007-2008 to 2015-2016 for females (N = 14318) and 2011-2012 to 2015-2016 for males (N = 7847). Temporal trends in coverage were assessed from 2007-2008 to 2011-2012 for females and from 2011-2012 to 2015-2016 for both sexes. Sensitivity and specificity of self/parent-reported vaccination were assessed using provider-verified vaccination records from a pilot study in 14-29 year-olds. In 2015-2016, ≥1 dose coverage among females was highest in 14-19 (54.7%) and 20-24 (56.0%) year-olds and lower in successively older age groups. Among males, ≥1 dose coverage was highest in 14-19 year-olds (39.5%) and lower at older ages. Coverage was similar in 9-13 year-old females and males. Between 2007-2008 and 2011-2012, there were increases among females younger than 30 years. Between 2011-2012 and 2015-2016, there were increases among female age groups including 20-39 year-olds; male coverage increased among ages 9-13, 14-19, and 20-24 years. Self/parent-reported receipt of ≥1 dose had a sensitivity and specificity of 87.0% and 83.3%. Performance was lower for 3 doses. While overall HPV vaccination coverage remains low, it is higher in females than males, except in 9-13 year-olds. There have been increases in coverage among many age groups, but coverage has stalled in younger females. Adequate validity was demonstrated for self/parent-reported vaccination of ≥1 dose, but not 3 doses, in a pilot study. Copyright © 2018 Elsevier Ltd. All rights reserved.
Dai, Yifei; Scuderi, Giles R; Bischoff, Jeffrey E; Bertin, Kim; Tarabichi, Samih; Rajgopal, Ashok
2014-12-01
The aim of this study was to comprehensively evaluate contemporary tibial component designs against global tibial anatomy. We hypothesized that anatomically designed tibial components offer increased morphological fit to the resected proximal tibia with increased alignment accuracy compared to symmetric and asymmetric designs. Using a multi-ethnic bone dataset, six contemporary tibial component designs were investigated, including anatomic, asymmetric, and symmetric design types. Investigations included (1) measurement of component conformity to the resected tibia using a comprehensive set of size and shape metrics; (2) assessment of component coverage on the resected tibia while ensuring clinically acceptable levels of rotation and overhang; and (3) evaluation of the incidence and severity of component downsizing due to adherence to rotational alignment and overhang requirements, and the associated compromise in tibial coverage. Differences in coverage were statistically compared across designs and ethnicities, as well as between placements with or without enforcement of proper rotational alignment. Compared to non-anatomic designs investigated, the anatomic design exhibited better conformity to resected tibial morphology in size and shape, higher tibial coverage (92% compared to 85-87%), more cortical support (posteromedial region), lower incidence of downsizing (3% compared to 39-60%), and less compromise of tibial coverage (0.5% compared to 4-6%) when enforcing proper rotational alignment. The anatomic design demonstrated meaningful increase in tibial coverage with accurate rotational alignment compared to symmetric and asymmetric designs, suggesting its potential for less intra-operative compromises and improved performance. III.
Altpeter, Ekkehardt; Wymann, Monica N; Richard, Jean-Luc; Mäusezahl-Feuz, Mirjam
2018-06-01
To evaluate the impact of the Swiss measles elimination strategy-including a mass media campaign-on vaccination coverage and awareness among young adults aged 20-29 years. Comparison of the results of two cross-sectional population surveys in 2012 and 2015. Documented vaccination coverage increased from 77 to 88% for two doses of measles vaccine. Major determinants of complete vaccination were survey year, birth cohort, sex and the absence of prior measles disease. If birth cohort and prior history of measles disease are included as factors in a multivariate model, the difference between 2012 and 2015 vanishes. The marked increase in complete measles vaccination coverage is due to a cohort effect, owing to the introduction of the second dose of vaccine in 1996. Most of the vaccinations were administered before the national strategy was implemented and vaccination catch-ups did not increase during the campaign in young adults. Nevertheless, this study provides evidence of an improvement in the awareness of measles and measles vaccination in young adults, which may result in an impact on measles vaccination coverage in the near future.
Role of shell diffusion area in incubating eggs at simulated high altitude.
Weiss, H S
1978-10-01
Embryonic development is inhibited when eggs are incubated at 9,100 m (0.3 atm) despite a normoxic environment. The problem apparently relates to respiratory gas exchange occurring by diffusion through gas-filled pores in the shell. Gaseous flux is therefore inversely proportional to ambient pressure and is affected by the physical characteristics of the ambient gas (Chapman-Enskog equation). Excess loss of H2O and CO2 occurs in eggs incubating at altitude and could be detrimental. Such increased loss should be correctable by decreasing diffusion area. This was tested by progressively increasing coverage of the shell with paraffin and incubating at simulated 0.3 ATA (225 Torr) in 100% O2. Uncoated eggs failed to hatch, but numbers of chicks increased with increased coverage. Maximum hatch was an extrapolated 90% of controls at 69% shell coverage. With further coverage, hatch size decreased. Egg weight loss, and estimate of H2O diffusion, was around three times controls in uncoated eggs but decreased linearly with paraffin coverage, reaching near normal at maximum hatch. Reduction of diffusion area to 0.3 normal at maximum hatch generally balanced the increased flux predicted for 0.3 ATA.
ERIC Educational Resources Information Center
Wright, Richard A.
1987-01-01
Compares coverage of women and crime in sociology journals published from 1956-1960 and from 1976-1980 with coverage in criminology texts published from 1956-1965 and from 1976-1985. Data shows despite recent increases in publication of research in journals, criminology texts show little improvement in their coverage of women and crime. Concludes…
Estimated cost of universal public coverage of prescription drugs in Canada
Morgan, Steven G.; Law, Michael; Daw, Jamie R.; Abraham, Liza; Martin, Danielle
2015-01-01
Background: With the exception of Canada, all countries with universal health insurance systems provide universal coverage of prescription drugs. Progress toward universal public drug coverage in Canada has been slow, in part because of concerns about the potential costs. We sought to estimate the cost of implementing universal public coverage of prescription drugs in Canada. Methods: We used published data on prescribing patterns and costs by drug type, as well as source of funding (i.e., private drug plans, public drug plans and out-of-pocket expenses), in each province to estimate the cost of universal public coverage of prescription drugs from the perspectives of government, private payers and society as a whole. We estimated the cost of universal public drug coverage based on its anticipated effects on the volume of prescriptions filled, products selected and prices paid. We selected these parameters based on current policies and practices seen either in a Canadian province or in an international comparator. Results: Universal public drug coverage would reduce total spending on prescription drugs in Canada by $7.3 billion (worst-case scenario $4.2 billion, best-case scenario $9.4 billion). The private sector would save $8.2 billion (worst-case scenario $6.6 billion, best-case scenario $9.6 billion), whereas costs to government would increase by about $1.0 billion (worst-case scenario $5.4 billion net increase, best-case scenario $2.9 billion net savings). Most of the projected increase in government costs would arise from a small number of drug classes. Interpretation: The long-term barrier to the implementation of universal pharmacare owing to its perceived costs appears to be unjustified. Universal public drug coverage would likely yield substantial savings to the private sector with comparatively little increase in costs to government. PMID:25780047
Estimated cost of universal public coverage of prescription drugs in Canada.
Morgan, Steven G; Law, Michael; Daw, Jamie R; Abraham, Liza; Martin, Danielle
2015-04-21
With the exception of Canada, all countries with universal health insurance systems provide universal coverage of prescription drugs. Progress toward universal public drug coverage in Canada has been slow, in part because of concerns about the potential costs. We sought to estimate the cost of implementing universal public coverage of prescription drugs in Canada. We used published data on prescribing patterns and costs by drug type, as well as source of funding (i.e., private drug plans, public drug plans and out-of-pocket expenses), in each province to estimate the cost of universal public coverage of prescription drugs from the perspectives of government, private payers and society as a whole. We estimated the cost of universal public drug coverage based on its anticipated effects on the volume of prescriptions filled, products selected and prices paid. We selected these parameters based on current policies and practices seen either in a Canadian province or in an international comparator. Universal public drug coverage would reduce total spending on prescription drugs in Canada by $7.3 billion (worst-case scenario $4.2 billion, best-case scenario $9.4 billion). The private sector would save $8.2 billion (worst-case scenario $6.6 billion, best-case scenario $9.6 billion), whereas costs to government would increase by about $1.0 billion (worst-case scenario $5.4 billion net increase, best-case scenario $2.9 billion net savings). Most of the projected increase in government costs would arise from a small number of drug classes. The long-term barrier to the implementation of universal pharmacare owing to its perceived costs appears to be unjustified. Universal public drug coverage would likely yield substantial savings to the private sector with comparatively little increase in costs to government. © 2015 Canadian Medical Association or its licensors.
The impact of the 2007-2009 recession on workers' health coverage.
Fronstin, Paul
2011-04-01
IMPACT OF THE RECESSION: The 2007-2009 recession has taken its toll on the percentage of the population with employment-based health coverage. While, since 2000, there has been a slow erosion in the percentage of individuals under age 65 with employment-based health coverage, 2009 was the first year in which the percentage fell below 60 percent, and marked the largest one-year decline in coverage. FEWER WORKERS WITH COVERAGE: The percentage of workers with coverage through their own job fell from 53.2 percent in 2008 to 52 percent in 2009, a 2.4 percent decline in the likelihood that a worker has coverage through his or her own job. The percentage of workers with coverage as a dependent fell from 17 percent in 2008 to 16.3 percent in 2009, a 4.5 percent drop in the likelihood that a worker has coverage as a dependent. These declines occurred as the unemployment rate increased from an average of 5.8 percent in 2008 to 9.3 percent in 2009 (and reached a high of 10.1 percent during 2009). FIRM SIZE/INDUSTRY: The decline in the percentage of workers with coverage from their own job affected workers in private-sector firms of all sizes. Among public-sector workers, the decline from 73.4 percent to 73 percent was not statistically significant. Workers in all private-sector industries experienced a statistically significant decline in coverage between 2008 and 2009. HOURS WORKED: Full-time workers experienced a decline in coverage that was statistically significant while part-time workers did not. Among full-time workers, those employed full year experienced a statistically significant decline in coverage from their own job. Those employed full time but for only part of the year did not experience a statistically significant change in coverage. Among part-time workers, those employed full year experienced a statistically significant increase in the likelihood of having coverage in their own name, as did part-time workers employed for only part of the year. ANNUAL EARNINGS: The decline in the percentage of workers with coverage through their own job was limited to workers with lower annual earnings. Statistically significant declines were not found among any group of workers with annual earnings of at least $40,000. Workers with a high school education or less experienced a statistically significant decline in the likelihood of having coverage. Neither workers with a college degree nor those with a graduate degree experienced a statistically significant decline in coverage through their own job. Workers of all races experienced statistically significant declines in coverage between 2008 and 2009. Both men and women experienced a statistically significant decline in the percentage with health coverage through their own job. IMPACT OF STRUCTURAL CHANGES TO THE WORK FORCE: The movement of workers from the manufacturing industry to the service sector continued between 2008 and 2009. The percentage of workers employed on a full-time basis decreased while the percentage working part time increased. While there was an overall decline in the percentage of full-time workers, that decline was limited to workers employed full year. The percentage of workers employed on a full-time, part-year basis increased between 2008 and 2009. The distribution of workers by annual earnings shifted from middle-income workers to lower-income workers between 2008 and 2009.
NASA Astrophysics Data System (ADS)
Sobocinski, Kathryn L.; Ciannelli, Lorenzo; Wakefield, W. Waldo; Yergey, Matthew E.; Johnson-Colegrove, Angela
2018-05-01
The juvenile demersal fish assemblage along the Pacific Northwest coast has received little attention relative to adult life history stages since pioneering work in the 1970s. Increasing severity of hypoxia along the Oregon coast in recent years has prompted investigations into the response of biota in this region. We used summer data (2008-2013) from a beam trawl survey targeting juvenile demersal fishes in soft-bottom habitats along the Oregon coast to describe patterns of distribution and abundance at fixed sampling stations (from 30 m to 100 m depth). We relate the assemblage and abundance of the common species to environmental variables and analyze condition of recently settled fish (<50 mm SL). Most of the captured fishes were young-of-the-year flatfishes, dominated by Butter Sole (Isopsetta isolepis), English Sole (Parophrys vetulus), Speckled Sanddab (Citharichthys stigmaeus), and Pacific Sanddab (Citharichthys sordidus). Community analysis of the full dataset showed some variation in species richness among years and high evenness across all sampling sites and years. Depth was a structuring variable for the community, indicated by multivariate nonmetric multidimensional scaling analysis. Generalized additive models for common flatfish species abundances during the summer months indicated depth preferences, with Butter Sole, English Sole, and Speckled Sanddab at shallower locations and Pacific Sanddab occurring at deeper locations farther offshore. Additionally, while most common species were collected in high abundances in hypoxic conditions, dissolved oxygen was a significant factor in determining flatfish abundance. Condition factor was weakly negatively impacted by low dissolved oxygen for the species assessed, but the strength of the relationship varied by species. Increased sampling frequency and spatial coverage would improve our understanding of this community, especially in light of changing environmental drivers such as decreasing pH, warming water, and episodic periods of low dissolved oxygen coinciding with settlement for many species.
Metcalf, C J E; Tatem, A; Bjornstad, O N; Lessler, J; O'Reilly, K; Takahashi, S; Cutts, F; Grenfell, B T
2015-05-01
Measles vaccination is estimated to have averted 13·8 million deaths between 2000 and 2012. Persisting heterogeneity in coverage is a major contributor to continued measles mortality, and a barrier to measles elimination and introduction of rubella-containing vaccine. Our objective is to identify determinants of inequities in coverage, and how vaccine delivery must change to achieve elimination goals, which is a focus of the WHO Decade of Vaccines. We combined estimates of travel time to the nearest urban centre (⩾50 000 people) with vaccination data from Demographic Health Surveys to assess how remoteness affects coverage in 26 African countries. Building on a statistical mapping of coverage against age and geographical isolation, we quantified how modifying the rate and age range of vaccine delivery affects national coverage. Our scenario analysis considers increasing the rate of delivery of routine vaccination, increasing the target age range of routine vaccination, and enhanced delivery to remote areas. Geographical isolation plays a key role in defining vaccine inequity, with greater inequity in countries with lower measles vaccine coverage. Eliminating geographical inequities alone will not achieve thresholds for herd immunity, indicating that changes in delivery rate or age range of routine vaccination will be required. Measles vaccine coverage remains far below targets for herd immunity in many countries on the African continent and is likely to be inadequate for achieving rubella elimination. The impact of strategies such as increasing the upper age range eligible for routine vaccination should be considered.
Thermodynamics of Alkanethiol Self-Assembled Monolayer Assembly on Pd Surfaces.
Kumar, Gaurav; Van Cleve, Timothy; Park, Jiyun; van Duin, Adri; Medlin, J Will; Janik, Michael J
2018-06-05
We investigate the structure and binding energy of alkanethiolate self-assembled monolayers (SAMs) on Pd (111), Pd (100), and Pd (110) facets at different coverages. Dispersion-corrected density functional theory calculations are used to correlate the binding energy of alkanethiolates with alkyl chain length and coverage. The equilibrium coverage of thiolate layers strongly prefers 1/3 monolayer (ML) on the Pd (111) surface. The coverage of thiolates varies with chemical potential on Pd (100) and Pd (110), increasing from 1/3 to 1/2 ML on (100) and from 1/4 to 1/2 ML on (110) as the thiol chemical potential is increased. Higher coverages are driven by attractive dispersion interactions between the extended alkyl chains, such that transitions to higher coverages occur at lower thiol chemical potentials for longer chain thiolates. Stronger adsorption to the Pd (100) surface causes the equilibrium Wulff construction of Pd particles to take on a cubic shape upon saturation with thiols. The binding of H, O, and CO adsorbates is weakened as the thiolate coverage is increased, with saturation coverages causing unfavorable binding of O and CO on Pd (100) and weakened binding on other facets. Temperature-dependent CO diffuse reflectance infrared Fourier transform spectroscopy experiments are used to corroborate the weakened binding of CO in the presence of thiolate SAMs of varying surface density. Preliminary results of multiscale modeling efforts on the Pd-thiol system using a reactive force field, ReaxFF, are also discussed.
[Gaps in effective coverage by socioeconomic status and poverty condition].
Gutiérrez, Juan Pablo
2013-01-01
To analyze, in the context of increased health protection in Mexico, the gaps by socioeconomic status and poverty condition on effective coverage of selected preventive interventions. Data from the National Health & Nutrition Survey 2012 and 2006, using previously defined indicators of effective coverage and stratifying them by socioeconomic (SE) status and multidimensional poverty condition. For vaccination interventions, immunological equity has been maintained in Mexico. For indicators related to preventive interventions provided at the clinical setting, effective coverage is lower among those in the lowest SE quintile and among people living in multidimensional poverty. Comparing 2006 and 2012, there is no evidence on gap reduction. While health protection has significantly increased in Mexico, thus reducing SE gaps, those gaps are still important in magnitude for effective coverage of preventive interventions.
Schafer, Rachel M; Handal, Paul J; Brawer, Peter A; Ubinger, Megan
2011-06-01
This study was a follow up investigation of Brawer et al.'s (Prof Psychol Res Pr 33(2):203-206, 2002) survey of education and training of clinical psychologists in religion/spirituality. Directors of clinical training were surveyed to determine whether changes had occurred in the coverage of religion and spirituality through course work, research, supervision, and in the systematic coverage of the content area. Results indicated an increased coverage in the areas of supervision, dedicated courses, inclusion as part of another course, and research. There was no increase in systematic coverage, but significantly more programs provided at least some coverage. The current study also assesses other areas of incorporation as well as directors' opinions regarding the importance of religion/spirituality in the field of psychology.
Use of pulse oximeter placed on a gastroschisis silo to monitor intestinal oxygen saturation.
Kim, Sunghoon; Betts, James; Yedlin, Steve; Rowe, Richard; Idowu, Olajire
2006-09-01
The use of a silo for temporary coverage of exposed viscera for newborns with gastroschisis has allowed gradual reduction of the externalized intestine into the abdominal cavity. However, there has not been an easy way to monitor blood perfusion to the intestine within the silo other than with visual examination. In addition, visual examination of bowel through the silo is sometimes difficult for medical staff due to serositis and peel over the bowel. We have adopted an approach to monitor oxygen saturation of silo-contained intestine by placing a pulse oximeter sensor on the surface of the transparent silo to detect intestinal ischemia. Pulse oximeter sensors were applied on both a patient's distal extremity and the silo on five consecutive patients who were born with gastroschisis. The sensor was left on the silo during the entire period of gradual reduction. Perfusion index, pulse and oxygen saturation were observed and checked against the sensor placed on a peripheral extremity. The silo-placed pulse oximeter and peripheral pulse oximeter sensors showed a similar pulse and oxygen saturation throughout the reduction period in all five patients. In general, perfusion index was higher from the silo pulse oximeter compared to the peripheral pulse oximeter reading. A pulse oximeter can be used to monitor intestinal oxygen saturation contained within a silo and help modulate the rate of manual reduction of intestine.
The public cost of expanding coverage.
Sheils, J F; Baxter, R J; Haught, R A
1995-01-01
The 103d Congress considered several health care reform bills that would encourage voluntary expansions of coverage through insurance market reforms, new tax deductions for premiums, and direct premium subsidies for low-income persons. We found that insurance reforms alone will do little to expand coverage. We also found that most of the proposed tax deductions would go to persons who already have insurance and would have little impact on coverage. Premium subsidies for low-income persons would greatly increase coverage. However, coverage would change little for those who would have to pay all or part of the premium.
Cost of lifetime immunosuppression coverage for kidney transplant recipients.
Page, Timothy F; Woodward, Robert S
2008-01-01
On January 1, 2000, Medicare extended the coverage of immunosuppression medications from 3 years to life for elderly and disabled kidney transplant recipients. This research estimates the impact of extending this lifetime coverage to all kidney transplant recipients on Medicare's cash flows. The study finds that extending coverage to all kidney transplant recipients would have increased Medicare's net cash outflows if the coverage were extended for patients of all income levels. There is evidence that extending coverage to only patients in the lowest income quartile could have resulted in a net cost savings to Medicare.
The cost-effectiveness of male HPV vaccination in the United States.
Chesson, Harrell W; Ekwueme, Donatus U; Saraiya, Mona; Dunne, Eileen F; Markowitz, Lauri E
2011-10-26
The objective of this study was to estimate the cost-effectiveness of adding human papillomavirus (HPV) vaccination of 12-year-old males to a female-only vaccination program for ages 12-26 years in the United States. We used a simplified model of HPV transmission to estimate the reduction in the health and economic burden of HPV-associated diseases in males and females as a result of HPV vaccination. Estimates of the incidence, cost-per-case, and quality-of-life impact of HPV-associated health outcomes were based on the literature. The HPV-associated outcomes included were: cervical intraepithelial neoplasia (CIN); genital warts; juvenile-onset recurrent respiratory papillomatosis (RRP); and cervical, vaginal, vulvar, anal, oropharyngeal, and penile cancers. The cost-effectiveness of male vaccination depended on vaccine coverage of females. When including all HPV-associated outcomes in the analysis, the incremental cost per quality-adjusted life year (QALY) gained by adding male vaccination to a female-only vaccination program was $23,600 in the lower female coverage scenario (20% coverage at age 12 years) and $184,300 in the higher female coverage scenario (75% coverage at age 12 years). The cost-effectiveness of male vaccination appeared less favorable when compared to a strategy of increased female vaccination coverage. For example, we found that increasing coverage of 12-year-old girls would be more cost-effective than adding male vaccination even if the increased female vaccination strategy incurred program costs of $350 per additional girl vaccinated. HPV vaccination of 12-year-old males might potentially be cost-effective, particularly if female HPV vaccination coverage is low and if all potential health benefits of HPV vaccination are included in the analysis. However, increasing female coverage could be a more efficient strategy than male vaccination for reducing the overall health burden of HPV in the population. Published by Elsevier Ltd.
Expanding health insurance for children: examining the alternatives.
Fronstin, P; Pierron, B
1997-07-01
This Issue Brief examines the issue of uninsured children. The budget reconciliation legislation currently under congressional consideration earmarks $16 billion for new initiatives to provide health insurance coverage to approximately 5 million of the 10 million uninsured children during the next five years. Proposals to expand coverage among children include the use of tax credits, subsidies, vouchers, Medicaid program expansion, and expansion of state programs. However, these proposals do not address the decline in employment-based health insurance coverage--the underlying cause of the lack of coverage, to the extent that a cause can be identified. What is worse, some proposals to expand health insurance among children may discourage employers from offering coverage. Between 1987 and 1995, the percentage of children with employment-based health insurance declined from 66.7 percent to 58.6 percent. Despite this trend, the percentage of children without any form of health insurance coverage barely increased. In 1987, 13.1 percent were uninsured, compared with 13.8 percent in 1995. Medicaid program expansions helped to alleviate the effects of the decline in employment-based health insurance coverage among children and the potential increase in the number of uninsured children. Between 1987 and 1995, the percentage of children enrolled in the Medicaid program increased from 15.5 percent to 23.2 percent. Some questions to consider in assessing approaches to improving children's health insurance coverage include the following: If the government intervenes, should it do so through a compulsory mechanism or a voluntary system? Is the employment-based system "worth saving" for children? In other words, are the market interventions necessary to keep this system functioning for children too regulatory, too intrusive, and too cumbersome to be practical? In addition to reforming the employment-based system, what reforms are necessary in order to reach those families who have no coverage through the work place? Which approaches are both efficient and politically acceptable? Employment-based coverage of children will likely continue. The challenge for lawmakers is to find a way to cover more uninsured children without eroding employment-based coverage. Several current legislative proposals attempt to avoid this problem by excluding children who have access to employment-based coverage. Without such a requirement, the opportunity to purchase coverage at a discount would create incentives for some low-income employees to drop dependent/family coverage, which in turn could lead some employers to drop their health plans.
Cancer trial enrollment after state-mandated reimbursement.
Gross, C P; Murthy, V; Li, Y; Kaluzny, A D; Krumholz, H M
2004-07-21
Recruitment of patients into cancer research studies is exceedingly difficult, particularly for early phase trials. Payer reimbursement policies are a frequently cited barrier. We examined whether state policies that ensure coverage of routine medical care costs for cancer trial participants are associated with an increase in clinical trial enrollment. We used logistic Poisson regressions to analyze enrollment in National Cancer Institute phase II and phase III Clinical Trials Cooperative Group trials and compared changes in trial enrollment rates between 1996 and 2001 of privately insured cancer patients who resided in the four states that enacted coverage policies in 1999 with enrollment rates in states without such policies. All statistical tests were two-sided. Trial enrollment rates increased in the coverage and noncoverage states by 24.9% (95% confidence interval [CI] = 22.8% to 27.0%) and 28.8% (95% CI = 27.7% to 29.8%) per year, respectively, from 1996 through 2001. After implementation of the coverage policies in 1999 in four states, there was a 21.7% (95% CI = 3.8% to 42.6%) annual increase in phase II trial enrollment in coverage states, compared with a 15.6% (95% CI = 8.8% to 21.8%) annual decrease in noncoverage states (P<.001). After accounting for secular trend, cancer type, and race in multivariable analyses, the odds ratio (OR) for a phase II trial participant residing in a coverage versus a noncoverage state after 1999 was 1.59 per year (95% CI = 1.22 to 2.07; P =.001). In a multivariable analysis of phase III trial participation, there was a decrease in the odds of residing in a coverage state after 1999 (OR = 0.90, 95% CI = 0.84 to 0.98; P =.011). State coverage policies were associated with a statistically significant increase in phase II cancer trial participation and did not increase phase III cancer trial enrollment.
Harder, Valerie S; Barry, Sara E; Ahrens, Bridget; Davis, Wendy S; Shaw, Judith S
Despite the proven benefits of immunizations, coverage remains low in many states, including Vermont. This study measured the impact of a quality improvement (QI) project on immunization coverage in childhood, school-age, and adolescent groups. In 2013, a total of 20 primary care practices completed a 7-month QI project aimed to increase immunization coverage among early childhood (29-33 months), school-age (6 years), and adolescent (13 years) age groups. For this study, we examined random cross-sectional medical record reviews from 12 of the 20 practices within each age group in 2012, 2013, and 2014 to measure improvement in immunization coverage over time using chi-squared tests. We repeated these analyses on population-level data from Vermont's immunization registry for the 12 practices in each age group each year. We used difference-in-differences regressions in the immunization registry data to compare improvements over time between the 12 practices and those not participating in QI. Immunization coverage increased over 3 years for all ages and all immunization series (P ≤ .009) except one, as measured by medical record review. Registry results aligned partially with medical record review with increases in early childhood and adolescent series over time (P ≤ .012). Notably, the adolescent immunization series completion, including human papillomavirus, increased more than in the comparison practices (P = .037). Medical record review indicated that QI efforts led to increases in immunization coverage in pediatric primary care. Results were partially validated in the immunization registry particularly among early childhood and adolescent groups, with a population-level impact of the intervention among adolescents. Copyright © 2018 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.
Lee, Bruce Y.; Bartsch, Sarah M.; Stone, Nathan T. B.; Zhang, Shufang; Brown, Shawn T.; Chatterjee, Chandrani; DePasse, Jay V.; Zenkov, Eli; Briët, Olivier J. T.; Mendis, Chandana; Viisainen, Kirsi; Candrinho, Baltazar; Colborn, James
2017-01-01
Malaria-endemic countries have to decide how much of their limited resources for vector control to allocate toward implementing long-lasting insecticidal nets (LLINs) versus indoor residual spraying (IRS). To help the Mozambique Ministry of Health use an evidence-based approach to determine funding allocation toward various malaria control strategies, the Global Fund convened the Mozambique Modeling Working Group which then used JANUS, a software platform that includes integrated computational economic, operational, and clinical outcome models that can link with different transmission models (in this case, OpenMalaria) to determine the economic value of vector control strategies. Any increase in LLINs (from 80% baseline coverage) or IRS (from 80% baseline coverage) would be cost-effective (incremental cost-effectiveness ratios ≤ $114/disability-adjusted life year averted). However, LLIN coverage increases tend to be more cost-effective than similar IRS coverage increases, except where both pyrethroid resistance is high and LLIN usage is low. In high-transmission northern regions, increasing LLIN coverage would be more cost-effective than increasing IRS coverage. In medium-transmission central regions, changing from LLINs to IRS would be more costly and less effective. In low-transmission southern regions, LLINs were more costly and less effective than IRS, due to low LLIN usage. In regions where LLINs are more cost-effective than IRS, it is worth considering prioritizing LLIN coverage and use. However, IRS may have an important role in insecticide resistance management and epidemic control. Malaria intervention campaigns are not a one-size-fits-all solution, and tailored approaches are necessary to account for the heterogeneity of malaria epidemiology. PMID:28719286
NASA Astrophysics Data System (ADS)
Mei, Donghai; Ge, Qingfeng; Neurock, Matthew; Kieken, Laurent; Lerou, Jan
First-principles-based kinetic Monte Carlo simulation was used to track the elementary surface transformations involved in the catalytic decomposition of NO over Pt(100) and Rh(100) surfaces under lean-burn operating conditions. Density functional theory (DFT) calculations were carried out to establish the structure and energetics for all reactants, intermediates and products over Pt(100) and Rh(100). Lateral interactions which arise from neighbouring adsorbates were calculated by examining changes in the binding energies as a function of coverage and different coadsorbed configurations. These data were fitted to a bond order conservation (BOC) model which is subsequently used to establish the effects of coverage within the simulation. The intrinsic activation barriers for all the elementary reaction steps in the proposed mechanism of NO reduction over Pt(100) were calculated by using DFT. These values are corrected for coverage effects by using the parametrized BOC model internally within the simulation. This enables a site-explicit kinetic Monte Carlo simulation that can follow the kinetics of NO decomposition over Pt(100) and Rh(100) in the presence of excess oxygen. The simulations are used here to model various experimental protocols including temperature programmed desorption as well as batch catalytic kinetics. The simulation results for the temperature programmed desorption and decomposition of NO over Pt(100) and Rh(100) under vacuum condition were found to be in very good agreement with experimental results. NO decomposition is strongly tied to the temporal number of sites that remain vacant. Experimental results show that Pt is active in the catalytic reaction of NO into N2 and NO2 under lean-burn conditions. The simulated reaction orders for NO and O2 were found to be +0.9 and -0.4 at 723 K, respectively. The simulation also indicates that there is no activity over Rh(100) since the surface becomes poisoned by oxygen.
Some demographic issues affecting private health insurance.
Hanning, Brian
2004-01-01
There will be significant changes in the demography of persons with Private Health Insurance (PHI). Two methods of projecting PHI coverage are discussed in this paper. The first assumes the only factors affecting PHI coverage are demographic change and mortality and facilitates comparisons between actual and projected PHI coverage. The second projects the percentage of the population insured in each five year age cohort, and makes allowance for changes in PHI coverage due to all factors. Demographic change will increase Registered Health Benefit Organization (RHBO) premiums by 1.7% per annum. The role of these projections in analysing the effect of future premium increases on PHI retention rates is also discussed.
Gould, Elise
2014-01-01
Americans under age 65 rely on a healthy labor market for almost all facets of economic security. While 2012 marked the first year in more than a decade that the employer-sponsored health insurance (ESI) coverage rate for the under-65 population did not decline, employer-sponsored health insurance continues to fail American families. If the coverage rate had not fallen 10.8 percentage points as it did from 2000 to 2012, as many as 29 million more people under age 65 would have had ESI in 2012. Even with the end of its longstanding decline, ESI coverage rates among men and women, white and non-white, high and low income, white and blue collar, young and old remain far lower than they were in 2000. Over this period, the increase in uninsured Americans was not as steep as the fall in ESI because of increases in public coverage, including Medicaid, the Children's Health Insurance Program, and Medicare. These programs were particularly effective in reducing the share of children uninsured over the 2000s. Additionally, key components in the Patient Protection and Affordable Care Act shielded young adults from further coverage losses.
Media coverage and public reaction to a celebrity cancer diagnosis.
Metcalfe, D; Price, C; Powell, J
2011-03-01
Celebrity diagnoses can have important effects on public behaviour. UK television celebrity Jade Goody died from cervical cancer in 2009. We investigated the impact of her illness on media coverage of cervical cancer prevention, health information seeking behaviour and cervical screening coverage. National UK newspaper articles containing the words 'Jade Goody' and 'cancer' were examined for public health messages. Google Insights for Search was used to quantify Internet searches as a measure of public health information seeking. Cervical screening coverage data were examined for temporal associations with this story. Of 1203 articles, 116 (9.6%) included a clear public health message. The majority highlighted screening (8.2%). Fewer articles provided advice about vaccination (3.0%), number of sexual partners (1.4%), smoking (0.6%) and condom use (0.4%). Key events were associated with increased Internet searches for 'cervical cancer' and 'smear test', although only weakly with searches for 'HPV'. Cervical screening coverage increased during this period. Increased public interest in disease prevention can follow a celebrity diagnosis. Although media coverage sometimes included public health information, articles typically focused on secondary instead of primary prevention. There is further potential to maximize the public health benefit of future celebrity diagnoses.
Association mapping identifies loci for canopy coverage in diverse soybean genotypes
USDA-ARS?s Scientific Manuscript database
Rapid establishment of canopy coverage decreases soil evaporation relative to transpiration (T), improves water use efficiency (WUE) and light interception, and increases soybean competitiveness against weeds. The objective of this study was to identify genomic loci associated with canopy coverage (...
Maser radiometer for cosmic background radiation anisotropy measurements
NASA Technical Reports Server (NTRS)
Fixsen, D. J.; Wilkinson, D. T.
1982-01-01
A maser amplifier was incorporated into a low noise radiometer designed to measure large-scale anisotropy in the 3 deg K microwave background radiation. To minimize emission by atmospheric water vapor and oxygen, the radiometer is flown in a small balloon to an altitude to 25 km. Three successful flights were made - two from Palestine, Texas and one from Sao Jose dos Campos, Brazil. Good sky coverage is important to the experiment. Data from the northern hemisphere flights has been edited and calibrated.
Increasing Health Insurance Costs and the Decline in Insurance Coverage
Chernew, Michael; Cutler, David M; Keenan, Patricia Seliger
2005-01-01
Objective To determine the impact of rising health insurance premiums on coverage rates. Data Sources & Study Setting Our analysis is based on two cohorts of nonelderly Americans residing in 64 large metropolitan statistical areas (MSAs) surveyed in the Current Population Survey in 1989–1991 and 1998–2000. Measures of premiums are based on data from the Health Insurance Association of America and the Kaiser Family Foundation/Health Research and Educational Trust Survey of Employer-Sponsored Health Benefits. Study Design Probit regression and instrumental variable techniques are used to estimate the association between rising local health insurance costs and the falling propensity for individuals to have any health insurance coverage, controlling for a rich array of economic, demographic, and policy covariates. Principal Findings More than half of the decline in coverage rates experienced over the 1990s is attributable to the increase in health insurance premiums (2.0 percentage points of the 3.1 percentage point decline). Medicaid expansions led to a 1 percentage point increase in coverage. Changes in economic and demographic factors had little net effect. The number of people uninsured could increase by 1.9–6.3 million in the decade ending 2010 if real, per capita medical costs increase at a rate of 1–3 percentage points, holding all else constant. Conclusions Initiatives aimed at reducing the number of uninsured must confront the growing pressure on coverage rates generated by rising costs. PMID:16033490
Employer Health Insurance Offerings and Employee Enrollment Decisions
Polsky, Daniel; Stein, Rebecca; Nicholson, Sean; Bundorf, M Kate
2005-01-01
Objective To determine how the characteristics of the health benefits offered by employers affect worker insurance coverage decisions. Data Sources The 1996–1997 and the 1998–1999 rounds of the nationally representative Community Tracking Study Household Survey. Study Design We use multinomial logistic regression to analyze the choice between own-employer coverage, alternative source coverage, and no coverage among employees offered health insurance by their employer. The key explanatory variables are the types of health plans offered and the net premium offered. The models include controls for personal, health plan, and job characteristics. Principal Findings When an employer offers only a health maintenance organization married employees are more likely to decline coverage from their employer and take-up another offer (odds ratio (OR)=1.27, p<.001), while singles are more likely to accept the coverage offered by their employer and less likely to be uninsured (OR=0.650, p<.001). Higher net premiums increase the odds of declining the coverage offered by an employer and remaining uninsured for both married (OR=1.023, p<.01) and single (OR=1.035, p<.001) workers. Conclusions The type of health plan coverage an employer offers affects whether its employees take-up insurance, but has a smaller effect on overall coverage rates for workers and their families because of the availability of alternative sources of coverage. Relative to offering only a non-HMO plan, employers offering only an HMO may reduce take-up among those with alternative sources of coverage, but increase take-up among those who would otherwise go uninsured. By modeling the possibility of take-up through the health insurance offers from the employer of the spouse, the decline in coverage rates from higher net premiums is less than previous estimates. PMID:16174133
Employer health insurance offerings and employee enrollment decisions.
Polsky, Daniel; Stein, Rebecca; Nicholson, Sean; Bundorf, M Kate
2005-10-01
To determine how the characteristics of the health benefits offered by employers affect worker insurance coverage decisions. The 1996-1997 and the 1998-1999 rounds of the nationally representative Community Tracking Study Household Survey. We use multinomial logistic regression to analyze the choice between own-employer coverage, alternative source coverage, and no coverage among employees offered health insurance by their employer. The key explanatory variables are the types of health plans offered and the net premium offered. The models include controls for personal, health plan, and job characteristics. When an employer offers only a health maintenance organization married employees are more likely to decline coverage from their employer and take-up another offer (odds ratio (OR)=1.27, p<.001), while singles are more likely to accept the coverage offered by their employer and less likely to be uninsured (OR=0.650, p<.001). Higher net premiums increase the odds of declining the coverage offered by an employer and remaining uninsured for both married (OR=1.023, p<.01) and single (OR=1.035, p<.001) workers. The type of health plan coverage an employer offers affects whether its employees take-up insurance, but has a smaller effect on overall coverage rates for workers and their families because of the availability of alternative sources of coverage. Relative to offering only a non-HMO plan, employers offering only an HMO may reduce take-up among those with alternative sources of coverage, but increase take-up among those who would otherwise go uninsured. By modeling the possibility of take-up through the health insurance offers from the employer of the spouse, the decline in coverage rates from higher net premiums is less than previous estimates.
NASA Astrophysics Data System (ADS)
Shuang, Zhou; Guili, Liu; Dazhi, Fan
2017-02-01
The electronic structure and optical properties of adsorbing O atoms on graphene with different O coverage are researched using the density functional theory based upon the first-principle study to obtain further insight into properties of graphene. The adsorption energies, band structures, the density of states, light absorption coefficient and reflectivity of each system are calculated theoretically after optimizing structures of each system with different O coverage. Our calculations show that adsorption of O atoms on graphene increases the bond length of C-C which adjacent to the O atoms. When the O coverage is 9.4%, the adsorption energy (3.91 eV) is the maximum, which only increases about 1.6% higher than that of 3.1% O coverage. We find that adsorbed O atoms on pristine graphene opens up indirect gap of about 0.493-0.952 eV. Adsorbing O atoms make pristine graphene from metal into a semiconductor. When the O coverage is 9.4%, the band gap (0.952 eV) is the maximum. Comparing with pristine graphene, we find the density of states at Fermi level of O atoms adsorbing on graphene with different coverage are significantly increased. We also find that light absorption coefficient and reflectivity peaks are significantly reduced, and the larger the coverage, the smaller the absorption coefficient and reflectivity peaks are. And the blue shift phenomenon appears.
5 CFR 531.402 - Employee coverage.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Employee coverage. 531.402 Section 531.402 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER THE GENERAL SCHEDULE Within-Grade Increases § 531.402 Employee coverage. (a) Except as provided in paragraph...
Cho, Hyunyi; Hall, Jennifer G.; Kosmoski, Carin; Fox, Rebekah L.; Mastin, Teresa
2008-01-01
The majority of tanning bed users in the U.S. are women. Previous health communication research frequently focused on the risk of skin cancer, but few studies assessed the mediated communication environment that may surround women’s beliefs and behaviors relevant to tanning. A content analysis of articles in eight magazines targeting girls, young women, older women, and women who are interested in fitness during the ten-year period of 1997–2006 was conducted. The amount of coverage of tanning bed use consequences was less than 50% of the coverage of tanning benefits. About 40% of the tanning benefits coverage touted looking healthy. The coverage of prevention methods focused on sunscreen use (55%), while the more important methods (e.g., protective clothing use) were rarely featured. Longitudinally, the coverage of the risk and prevention relevant issues increased between 1997 and 2006. The data indicate that the coverage of tanning benefits also increased during the same period. PMID:20228954
Tran, Linda Diem
2016-01-01
A difference-in-difference approach was used to compare the effects of same-sex domestic partnership, civil union, and marriage policies on same- and different-sex partners who could have benefitted from their partners’ employer-based insurance (EBI) coverage. Same-sex partners had 78% lower odds (ME=-21%) of having EBI compared to different-sex partners, adjusting for socioeconomic and health-related factors. Same-sex partners living in states that recognized same-sex marriage or domestic partnership had 89% greater odds of having EBI compared to those in states that did not recognize same-sex unions (ME=5%). The impact of same-sex legislation on increasing take-up of dependent EBI coverage among lesbians, gay men, and bisexual individuals (LGBs) was modest, and domestic partnership legislation was equally as effective as same-sex marriage in increasing same-sex partner EBI coverage. Extending dependent EBI coverage to same-sex partners can mitigate gaps in coverage for a segment of the LGB population but will not eliminate them. PMID:26762647
School Entry Requirements and Coverage of Nontargeted Adolescent Vaccines
Reiter, Paul L.; Truong, Young K.; Rimer, Barbara K.; Brewer, Noel T.
2016-01-01
BACKGROUND: Low human papillomavirus (HPV) vaccination coverage is an urgent public health problem requiring action. To identify policy remedies to suboptimal HPV vaccination, we assessed the relationship between states’ school entry requirements and adolescent vaccination. METHODS: We gathered data on states’ school entry requirements for adolescent vaccination (tetanus, diphtheria, and pertussis [Tdap] booster; meningococcal; and HPV) from 2007 to 2012 from Immunization Action Coalition. The National Immunization Survey–Teen provided medical record–verified vaccination data for 99 921 adolescents. We calculated coverage (among 13- to 17-year-olds) for individual vaccinations and concomitant vaccination. HPV vaccination outcomes were among female adolescents. Analyses used weighted longitudinal multivariable models. RESULTS: States with requirements for Tdap booster and meningococcal vaccination had 22 and 24 percentage point increases in coverage for these vaccines, respectively, compared with other states (both P < .05). States with HPV vaccination requirements had <1 percentage point increase in coverage for this vaccine (P < .05). Tdap booster and meningococcal vaccination requirements, respectively, were associated with 8 and 4 percentage point spillover increases for HPV vaccination coverage (both P < .05) and with increases for concomitant vaccination (all P < .05). CONCLUSIONS: Ensuring all states have meningococcal vaccination requirements could improve the nation’s HPV vaccination coverage, given that many states already require Tdap booster but not meningococcal vaccination for school entry. Vaccination programs and clinicians should capitalize on changes in adolescent vaccination, including concomitant vaccination, that may arise after states adopt vaccination requirements. Additional studies are needed on the effects of HPV vaccination requirements and opt-out provisions. PMID:27940689
School Entry Requirements and Coverage of Nontargeted Adolescent Vaccines.
Moss, Jennifer L; Reiter, Paul L; Truong, Young K; Rimer, Barbara K; Brewer, Noel T
2016-12-01
Low human papillomavirus (HPV) vaccination coverage is an urgent public health problem requiring action. To identify policy remedies to suboptimal HPV vaccination, we assessed the relationship between states' school entry requirements and adolescent vaccination. We gathered data on states' school entry requirements for adolescent vaccination (tetanus, diphtheria, and pertussis [Tdap] booster; meningococcal; and HPV) from 2007 to 2012 from Immunization Action Coalition. The National Immunization Survey-Teen provided medical record-verified vaccination data for 99 921 adolescents. We calculated coverage (among 13- to 17-year-olds) for individual vaccinations and concomitant vaccination. HPV vaccination outcomes were among female adolescents. Analyses used weighted longitudinal multivariable models. States with requirements for Tdap booster and meningococcal vaccination had 22 and 24 percentage point increases in coverage for these vaccines, respectively, compared with other states (both P < .05). States with HPV vaccination requirements had <1 percentage point increase in coverage for this vaccine (P < .05). Tdap booster and meningococcal vaccination requirements, respectively, were associated with 8 and 4 percentage point spillover increases for HPV vaccination coverage (both P < .05) and with increases for concomitant vaccination (all P < .05). Ensuring all states have meningococcal vaccination requirements could improve the nation's HPV vaccination coverage, given that many states already require Tdap booster but not meningococcal vaccination for school entry. Vaccination programs and clinicians should capitalize on changes in adolescent vaccination, including concomitant vaccination, that may arise after states adopt vaccination requirements. Additional studies are needed on the effects of HPV vaccination requirements and opt-out provisions. Copyright © 2016 by the American Academy of Pediatrics.
Tsu, Vivien; Jeronimo, Jose; Mvundura, Mercy; Lee, Kyueun; Kim, Jane J.
2017-01-01
Cervical cancer is a leading cause of cancer death worldwide, with 85% of the disease burden residing in less developed regions. To inform evidence‐based decision‐making as cervical cancer screening programs are planned, implemented, and scaled in low‐ and middle‐income countries, we used cost and test performance data from the START‐UP demonstration project in Uganda and a microsimulation model of HPV infection and cervical carcinogenesis to quantify the health benefits, distributional equity, cost‐effectiveness, and financial impact of either (1) improving access to cervical cancer screening or (2) increasing the number of lifetime screening opportunities for women who already have access. We found that when baseline screening coverage was low (i.e., 30%), expanding coverage of screening once in a lifetime to 50% can yield comparable reductions in cancer risk to screening two or three times in a lifetime at 30% coverage, lead to greater reductions in health disparities, and cost 150 international dollars (I$) per year of life saved (YLS). At higher baseline screening coverage levels (i.e., 70%), screening three times in a lifetime yielded greater health benefits than expanding screening once in a lifetime to 90% coverage, and would have a cost‐effectiveness ratio (I$590 per YLS) below Uganda's per capita GDP. Given very low baseline coverage at present, we conclude that a policy focus on increasing access for previously unscreened women appears to be more compatible with improving both equity and efficiency than a focus on increasing frequency for a small subset of women. PMID:27925175
State of equity: childhood immunization in the World Health Organization African Region
Casey, Rebecca Mary; Hampton, Lee McCalla; Anya, Blanche-philomene Melanga; Gacic-Dobo, Marta; Diallo, Mamadou Saliou; Wallace, Aaron Stuart
2017-01-01
Introduction In 2010, the Global Vaccine Action Plan called on all countries to reach and sustain 90% national coverage and 80% coverage in all districts for the third dose of diphtheria-tetanus-pertussis vaccine (DTP3) by 2015 and for all vaccines in national immunization schedules by 2020. The aims of this study are to analyze recent trends in national vaccination coverage in the World Health Organization African Region andto assess how these trends differ by country income category. Methods We compared national vaccination coverage estimates for DTP3 and the first dose of measles-containing vaccine (MCV) obtained from the World Health Organization (WHO)/United Nations Children’s Fund (UNICEF) joint estimates of national immunization coverage for all African Region countries. Using United Nations (UN) population estimates of surviving infants and country income category for the corresponding year, we calculated population-weighted average vaccination coverage by country income category (i.e., low, lower middle, and upper middle-income) for the years 2000, 2005, 2010 and 2015. Results DTP3 coverage in the African Region increased from 52% in 2000 to 76% in 2015,and MCV1 coverage increased from 53% to 74% during the same period, but with considerable differences among countries. Thirty-six African Region countries were low income in 2000 with an average DTP3 coverage of 50% while 26 were low income in 2015 with an average coverage of 80%. Five countries were lower middle-income in 2000 with an average DTP3 coverage of 84% while 12 were lower middle-income in 2015 with an average coverage of 69%. Five countries were upper middle-income in 2000 with an average DTP3 coverage of 73% and eight were upper middle-income in 2015 with an average coverage of 76%. Conclusion Disparities in vaccination coverage by country persist in the African Region, with countries that were lower middle-income having the lowest coverage on average in 2015. Monitoring and addressing these disparities is essential for meeting global immunization targets. PMID:29296140
Lou, Jie; Blevins, Meridith; Ruan, Yuhua; Vermund, Sten H.; Tang, Sanyi; Webb, Glenn F.; Shepherd, Bryan E.; He, Xiong; Lu, Hongyan; Shao, Yiming; Qian, Han-Zhu
2014-01-01
Objective To project the HIV/AIDS epidemics among men who have sex with men (MSM) under different combinations of HIV testing and linkage to care (TLC) interventions including antiretroviral therapy (ART) in Beijing, China. Design Mathematical modeling. Methods Using a mathematical model to fit prevalence estimates from 2000–2010, we projected trends in HIV prevalence and incidence during 2011–2020 under five scenarios: (S1) current intervention levels by averaging 2000–2010 coverage; (S2) increased ART coverage with current TLC; (S3) increased TLC/ART coverage; (S4) increased condom use; and (S5) increased TLC/ART plus increased condom use. Results The basic reproduction number based upon the current level of interventions is significantly higher than 1 ( confidence interval (CI), 1.83–2.35), suggesting that the HIV epidemic will continue to increase to 2020. Compared to the 2010 prevalence of 7.8%, the projected HIV prevalence in 2020 for the five prevention scenarios will be: (S1) Current coverage: 21.4% (95% CI, 9.9–31.7%); (S2) Increased ART: 19.9% (95% CI, 9.9–28.4%); (S3) Increased TLC/ART: 14.5% (95% CI, 7.0–23.8%); (S4) Increased condom use: 13.0% (95% CI, 9.8–28.4%); and (S5) Increased TLC/ART and condom use: 8.7% (95% CI, 5.4–11.5%). HIV epidemic will continue to rise () for S1–S4 even with hyperbolic coverage in the sensitivity analysis, and is expected to decline () for S5. Conclusion Our transmission model suggests that Beijing MSM will have a rapidly rising HIV epidemic. Even enhanced levels of TLC/ART will not interrupt epidemic expansion, despite optimistic assumptions for coverage. Promoting condom use is a crucial component of combination interventions. PMID:24626165
Initial reactive sticking coefficient of O 2 on Si(111)-7 × 7 at elevated temperatures
NASA Astrophysics Data System (ADS)
Shklyaev, A. A.; Suzuki, Takanori
1996-05-01
Kinetics of the initial stage of oxide growth in the reaction of oxygen with Si(111)-7 × 7 at temperatures from room temperature to Ttr, and pressures from 5 × 10 -9 to 2 × 10 -7 Torr are investigated with optical second-harmonic generation, here temperature from oxide growth to Si etching without oxide growth. At a fixed pressure, the initial reactive sticking coefficient ( S0), obtained from the rate of oxide growth, decreases with increasing temperature to S0=0 at Ttr. We have found that the initial reacti sticking coefficient depends on the O 2 pressure. At temperatures above 320°C, the whole temperature dependence of S0 is situated in the region of higher temperatures for higher O 2 pressures ( Pox). Moreover, an additional bend in the temperature dependence of S0 is observed for Pox>1 × 10 -8 Torr near Ttr. A precursor-mediated adsorption model involving the reaction of formation is considered. The parameters of this model, obtained from the best fits to the experimental data, show that oxide growth rate constant increases and volatile SiO formation rate constant decreases as a function of O 2 pressure. At zero oxide coverage, the pressure dependence of the reaction rate constants is suggested to originate from interaction in the layer of the chemisorbed precursor species, whose coverage depends on the O 2 pressure. The volatile SiO formation is described by a three-step sequential two-channel process through the chemisorbed O 2 precursor species, whereas one of the channels with a larger activation energy is suggested to induce the additional bend in S0( T) near Ttr at higher O 2 pressures.
Cropley, Rachael L; Williams, Federico J; Urquhart, Andrew J; Vaughan, Owain P H; Tikhov, Mintcho S; Lambert, Richard M
2005-04-27
The selective oxidation of trans-methylstyrene, a phenyl-substituted propene that contains labile allylic hydrogen atoms, has been studied on Cu{111}. Mass spectrometry and synchrotron fast XPS were used to detect, respectively, desorbing gaseous products and the evolution of surface species as a function of temperature and time. Efficient partial oxidation occurs yielding principally the epoxide, and the behavior of the system is sensitive to the order in which reactants are adsorbed. The latter is understandable in terms of differences in the spatial distribution of oxygen adatoms; isolated adatoms lead to epoxidation, while islands of "oxidic" oxygen do not. NEXAFS data taken over a range of coverages and in the presence and absence of coadsorbed oxygen indicate that the adsorbed alkene lies essentially flat with the allylic hydrogen atoms close to the surface. The photoemission results and comparison with the corresponding behavior of styrene on Cu{111} strongly suggest that allylic hydrogen abstraction is indeed a critical factor that limits epoxidation selectivity. An overall mechanism consistent with the structural and reactive properties is proposed.
Chesson, Harrell W; Ekwueme, Donatus U; Saraiya, Mona; Dunne, Eileen F; Markowitz, Lauri E
2014-11-01
Using a previously published dynamic model, we illustrate the potential benefits of human papillomavirus vaccination among girls currently 12 years or younger in the United States. Increasing vaccine coverage of young girls to 80% would avert 53,300 lifetime cervical cancer cases versus 30% coverage and 28,800 cases versus 50% coverage.
Dworsky, Michael; Farmer, Carrie M.; Shen, Mimi
2018-01-01
Abstract This article describes the Affordable Care Act's (ACA's) effects on nonelderly veterans' insurance coverage and demand for Department of Veterans Affairs (VA) health care and assesses the coverage and VA utilization changes that could result from repealing the ACA. Although prior research has shown that the number of uninsured veterans fell after the ACA took effect, the implications of ACA repeal for veterans and, especially, for VA have received less attention. Besides providing a new coverage option to veterans who are not enrolled in VA, the ACA also had the potential to affect health care use among VA patients. Findings include the following: In 2013, prior to the major coverage expansions under the ACA, nearly one in ten nonelderly veterans were uninsured, lacking access to both VA coverage and non-VA health insurance. Uninsurance among nonelderly veterans fell by an adjusted 36 percent (3.3 percentage points) after implementation of the ACA, from 9.1 percent in 2013 to 5.8 percent in 2015. By increasing non-VA health insurance coverage for VA patients, the ACA likely reduced demand for VA care; the authors estimate that, if the gains in insurance coverage that occurred between 2013 and 2015 had not occurred, nonelderly veterans would have used about 1 percent more VA health care in 2015: 125,000 more office visits, 1,500 more inpatient surgeries, and 375,000 more prescriptions. Recent congressional proposals to repeal and replace the ACA would increase the number of uninsured nonelderly veterans and further increase demand for VA health care. PMID:29607249
Abdus, Salam; Hudson, Julie; Hill, Steven C; Selden, Thomas M
2014-08-01
Both Medicaid and the Children's Health Insurance Program (CHIP), which are run by the states and funded by federal and state dollars, offer health insurance coverage for low-income children. Thirty-three states charged premiums for children at some income ranges in CHIP or Medicaid in 2013. Using data from the 1999-2010 Medical Expenditure Panel Surveys, we show that the relationship between premiums and coverage varies considerably by income level and by parental access to employer-sponsored insurance. Among children with family incomes above 150 percent of the federal poverty level, a $10 increase in monthly premiums is associated with a 1.6-percentage-point reduction in Medicaid or CHIP coverage. In this income range, the increase in uninsurance may be higher among those children whose parents lack an offer of employer-sponsored insurance than among those whose parents have such an offer. Among children with family incomes of 101-150 percent of poverty, a $10 increase in monthly premiums is associated with a 6.7-percentage-point reduction in Medicaid or CHIP coverage and a 3.3-percentage-point increase in uninsurance. In this income range, the increase in uninsurance is even larger among children whose parents lack offers of employer coverage. Project HOPE—The People-to-People Health Foundation, Inc.
Nandi, Arijit; Loue, Sana; Galea, Sandro
2009-12-01
As the US recession deepens, furthering the debate about healthcare reform is now even more important than ever. Few plans aimed at facilitating universal coverage make any mention of increasing access for uninsured non-citizens living in the US, many of whom are legally restricted from certain types of coverage. We conducted a critical review of the public health literature concerning the health status and access to health services among immigrant populations in the US. Using examples from infectious and chronic disease epidemiology, we argue that access to health services is at the intersection of the health of uninsured immigrants and the general population and that extending access to healthcare to all residents of the US, including undocumented immigrants, is beneficial from a population health perspective. Furthermore, from a health economics perspective, increasing access to care for immigrant populations may actually reduce net costs by increasing primary prevention and reducing the emphasis on emergency care for preventable conditions. It is unlikely that proposals for universal coverage will accomplish their objectives of improving population health and reducing social disparities in health if they do not address the substantial proportion of uninsured non-citizens living in the US.
Oxygen and sulfur adsorption on vicinal surfaces of copper and silver: Preferred adsorption sites
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Da-Jiang; Thiel, Patricia A.
We present an extensive density functional theory (DFT) study of adsorption site energetics for oxygen and sulfur adsorbed on two vicinal surfaces of Cu and Ag, with the goal of identifying the most stable adsorption site(s), identifying trends and common themes, and comparing with experimental work in the literature where possible. We also present benchmark calculations for adsorption on the flat (111) and (100) surfaces. The first vicinal surface is the (211), and results are similar for both metals. Here, we find that the step-doubling reconstruction is favored with both adsorbates and is driven by the creation of a specialmore » stable fourfold hollow (4fh) site at the reconstructed step. Zig-zag chain structures consisting of X–M–X units (X = chalcogen, M = metal) at the step edge are considered, in which the special 4fh site is partially occupied. The zig-zag configuration is energetically competitive for oxygen but not sulfur. DFT results for oxygen agree with experiment in terms of the stability of the reconstruction, but contradict the original site assignment. The second vicinal surface is the (410), where again results are similar for both metals. For oxygen, DFT predicts that step sites are filled preferentially even at lowest coverage, followed by terrace sites, consistent with the experiment. For sulfur, in contrast, DFT predicts that terrace sites fill first. Oxygen forms O–M–O rows on the top edge of the step, where it occupies incomplete 4fh sites. This resolves an experimental ambiguity in the site assignment. Finally, for both the (211) and (410) surfaces, the interaction energy that stabilizes the X–M–X chain or row correlates with the linearity of the X–M–X unit, which may explain key differences between oxygen and sulfur.« less
Oxygen and sulfur adsorption on vicinal surfaces of copper and silver: Preferred adsorption sites
Liu, Da-Jiang; Thiel, Patricia A.
2018-03-28
We present an extensive density functional theory (DFT) study of adsorption site energetics for oxygen and sulfur adsorbed on two vicinal surfaces of Cu and Ag, with the goal of identifying the most stable adsorption site(s), identifying trends and common themes, and comparing with experimental work in the literature where possible. We also present benchmark calculations for adsorption on the flat (111) and (100) surfaces. The first vicinal surface is the (211), and results are similar for both metals. Here, we find that the step-doubling reconstruction is favored with both adsorbates and is driven by the creation of a specialmore » stable fourfold hollow (4fh) site at the reconstructed step. Zig-zag chain structures consisting of X–M–X units (X = chalcogen, M = metal) at the step edge are considered, in which the special 4fh site is partially occupied. The zig-zag configuration is energetically competitive for oxygen but not sulfur. DFT results for oxygen agree with experiment in terms of the stability of the reconstruction, but contradict the original site assignment. The second vicinal surface is the (410), where again results are similar for both metals. For oxygen, DFT predicts that step sites are filled preferentially even at lowest coverage, followed by terrace sites, consistent with the experiment. For sulfur, in contrast, DFT predicts that terrace sites fill first. Oxygen forms O–M–O rows on the top edge of the step, where it occupies incomplete 4fh sites. This resolves an experimental ambiguity in the site assignment. Finally, for both the (211) and (410) surfaces, the interaction energy that stabilizes the X–M–X chain or row correlates with the linearity of the X–M–X unit, which may explain key differences between oxygen and sulfur.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berg, Danielle A.; Skillman, Evan D.; Marble, Andrew R., E-mail: berg@astro.umn.edu, E-mail: skillman@astro.umn.edu, E-mail: amarble@nso.edu
We present new MMT spectroscopic observations of four dwarf galaxies representative of a larger sample observed by the Sloan Digital Sky Survey and identified by Peeples et al. as low-mass, high oxygen abundance outliers from the mass-metallicity relation. Peeples showed that these four objects (with metallicity estimates of 8.5 {<=} 12 + log(O/H) {<=} 8.8) have oxygen abundance offsets of 0.4-0.6 dex from the M{sub B} luminosity-metallicity relation. Our new observations extend the wavelength coverage to include the [O II] {lambda}{lambda}3726, 3729 doublet, which adds leverage in oxygen abundance estimates and allows measurements of N/O ratios. All four spectra aremore » low excitation, with relatively high N/O ratios (N/O {approx}> 0.10), each of which tend to bias estimates based on strong emission lines toward high oxygen abundances. These spectra all fall in a regime where the 'standard' strong-line methods for metallicity determinations are not well calibrated either empirically or by photoionization modeling. By comparing our spectra directly to photoionization models, we estimate oxygen abundances in the range of 7.9 {<=} 12 + log (O/H) {<=} 8.4, consistent with the scatter of the mass-metallicity relation. We discuss the physical nature of these galaxies that leads to their unusual spectra (and previous classification as outliers), finding their low excitation, elevated N/O, and strong Balmer absorption are consistent with the properties expected from galaxies evolving past the 'Wolf-Rayet galaxy' phase. We compare our results to the 'main' sample of Peeples and conclude that they are outliers primarily due to enrichment of nitrogen relative to oxygen and not due to unusually high oxygen abundances for their masses or luminosities.« less
Dental Care Coverage and Use: Modeling Limitations and Opportunities
Moeller, John F.; Chen, Haiyan
2014-01-01
Objectives. We examined why older US adults without dental care coverage and use would have lower use rates if offered coverage than do those who currently have coverage. Methods. We used data from the 2008 Health and Retirement Study to estimate a multinomial logistic model to analyze the influence of personal characteristics in the grouping of older US adults into those with and those without dental care coverage and dental care use. Results. Compared with persons with no coverage and no dental care use, users of dental care with coverage were more likely to be younger, female, wealthier, college graduates, married, in excellent or very good health, and not missing all their permanent teeth. Conclusions. Providing dental care coverage to uninsured older US adults without use will not necessarily result in use rates similar to those with prior coverage and use. We have offered a model using modifiable factors that may help policy planners facilitate programs to increase dental care coverage uptake and use. PMID:24328635
Dental Care Coverage and Use: Modeling Limitations and Opportunities
Moeller, John F.; Chen, Haiyan
2014-01-01
Objectives. We examined why older US adults without dental care coverage and use would have lower use rates if offered coverage than do those who currently have coverage. Methods. We used data from the 2008 Health and Retirement Study to estimate a multinomial logistic model to analyze the influence of personal characteristics in the grouping of older US adults into those with and those without dental care coverage and dental care use. Results. Compared with persons with no coverage and no dental care use, users of dental care with coverage were more likely to be younger, female, wealthier, college graduates, married, in excellent or very good health, and not missing all their permanent teeth. Conclusions. Providing dental care coverage to uninsured older US adults without use will not necessarily result in use rates similar to those with prior coverage and use. We have offered a model using modifiable factors that may help policy planners facilitate programs to increase dental care coverage uptake and use. PMID:25343171
Chemical gating of epitaxial graphene through ultrathin oxide layers.
Larciprete, Rosanna; Lacovig, Paolo; Orlando, Fabrizio; Dalmiglio, Matteo; Omiciuolo, Luca; Baraldi, Alessandro; Lizzit, Silvano
2015-08-07
We achieved a controllable chemical gating of epitaxial graphene grown on metal substrates by exploiting the electrostatic polarization of ultrathin SiO2 layers synthesized below it. Intercalated oxygen diffusing through the SiO2 layer modifies the metal-oxide work function and hole dopes graphene. The graphene/oxide/metal heterostructure behaves as a gated plane capacitor with the in situ grown SiO2 layer acting as a homogeneous dielectric spacer, whose high capacity allows the Fermi level of graphene to be shifted by a few hundreds of meV when the oxygen coverage at the metal substrate is of the order of 0.5 monolayers. The hole doping can be finely tuned by controlling the amount of interfacial oxygen, as well as by adjusting the thickness of the oxide layer. After complete thermal desorption of oxygen the intrinsic doping of SiO2 supported graphene is evaluated in the absence of contaminants and adventitious adsorbates. The demonstration that the charge state of graphene can be changed by chemically modifying the buried oxide/metal interface hints at the possibility of tuning the level and sign of doping by the use of other intercalants capable of diffusing through the ultrathin porous dielectric and reach the interface with the metal.
Reaction rate kinetics for in situ combustion retorting of Michigan Antrim oil shale
Rostam-Abadi, M.; Mickelson, R.W.
1984-01-01
The intrinsic reaction rate kinetics for the pyrolysis of Michigan Antrim oil shale and the oxidation of the carbonaceous residue of this shale have been determined using a thermogravimetric analysis method. The kinetics of the pyrolysis reaction were evaluated from both isothermal and nonisothermal rate data. The reaction was found to be second-order with an activation energy of 252.2 kJ/mole, and with a frequency factor of 9.25 ?? 1015 sec-1. Pyrolysis kinetics were not affected by heating rates between 0.01 to 0.67??K/s. No evidence of any reactions among the oil shale mineral constituents was observed at temperatures below 1173??K. However, it was found that the presence of pyrite in oil shale reduces the primary devolatilization rate of kerogen and increases the amount of residual char in the spent shale. Carbonaceous residues which were prepared by heating the oil shale at a rate of 0.166??K/s to temperatures between 923??K and 1073??K, had the highest reactivities when oxidized at 0.166??K/s in a gas having 21 volume percent oxygen. Oxygen chemisorption was found to be the initial precursor to the oxidation process. The kinetics governing oxygen chemisorption is (Equation Presented) where X is the fractional coverage. The oxidation of the carbonaceous residue was found also to be second-order. The activation energy and the frequency factor determined from isothermal experiments were 147 kJ/mole and 9.18??107 sec-1 respectively, while the values of these parameters obtained from a nonisothermal experiment were 212 kJ/mole and 1.5??1013 sec-1. The variation in the rate constants is attributed to the fact that isothermal and nonisothermal analyses represent two different aspects of the combustion process.
5 CFR 531.402 - Employee coverage.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Employee coverage. 531.402 Section 531... GENERAL SCHEDULE Within-Grade Increases § 531.402 Employee coverage. (a) Except as provided in paragraph (b) of this section, this subpart applies to employees who— (1) Are classified and paid under the...
Berry, Stephen A.; Fleishman, John A.; Yehia, Baligh R.; Cheever, Laura W.; Hauck, Heather; Korthuis, P. Todd; Mathews, W. Christopher; Keruly, Jeanne; Nijhawan, Ank E.; Agwu, Allison L.; Somboonwit, Charurut; Moore, Richard D.; Gebo, Kelly A.
2016-01-01
Background. Before implementation of the Patient Protection and Affordable Care Act (ACA) in 2014, 100 000 persons living with human immunodeficiency virus (HIV) (PLWH) lacked healthcare coverage and relied on a safety net of Ryan White HIV/AIDS Program support, local charities, or uncompensated care (RWHAP/Uncomp) to cover visits to HIV providers. We compared HIV provider coverage before (2011–2013) versus after (first half of 2014) ACA implementation among a total of 28 374 PLWH followed up in 4 sites in Medicaid expansion states (California, Oregon, and Maryland), 4 in a state (New York) that expanded Medicaid in 2001, and 2 in nonexpansion states (Texas and Florida). Methods. Multivariate multinomial logistic models were used to assess changes in RWHAP/Uncomp, Medicaid, and private insurance coverage, using Medicare as a referent. Results. In expansion state sites, RWHAP/Uncomp coverage decreased (unadjusted, 28% before and 13% after ACA; adjusted relative risk ratio [ARRR], 0.44; 95% confidence interval [CI], .40–.48). Medicaid coverage increased (23% and 38%; ARRR, 1.82; 95% CI, 1.70–1.94), and private coverage was unchanged (21% and 19%; 0.96; .89–1.03). In New York sites, both RWHAP/Uncomp (20% and 19%) and Medicaid (50% and 50%) coverage were unchanged, while private coverage decreased (13% and 12%; ARRR, 0.86; 95% CI, .80–.92). In nonexpansion state sites, RWHAP/Uncomp (57% and 52%) and Medicaid (18% and 18%) coverage were unchanged, while private coverage increased (4% and 7%; ARRR, 1.79; 95% CI, 1.62–1.99). Conclusions. In expansion state sites, half of PLWH relying on RWHAP/Uncomp coverage shifted to Medicaid, while in New York and nonexpansion state sites, reliance on RWHAP/Uncomp remained constant. In the first half of 2014, the ACA did not eliminate the need for RWHAP safety net provider visit coverage. PMID:27143660
Lu, Ming; Chu, Yao-Zhu; Yu, Wen-Zhou; Scherpbier, Robert; Zhou, Yu-Qing; Zhu, Xu; Su, Qi-Ru; Duan, Meng-Juan; Zhang, Xuan; Cui, Fu-Qiang; Wang, Hua-Qing; Zhou, Yi-Biao; Jiang, Qing-Wu
2017-04-24
Communication for Development (C4D) is a strategy promoted by the United Nations Children's Fund to foster positive and measurable changes at the individual, family, community, social, and policy levels of society. In western China, C4D activities have previously been conducted as part of province-level immunization programs. In this study, we evaluated the association of C4D with changes in parental knowledge of immunization services, measles disease, and measles vaccine, and changes in their children's measles vaccine coverage. From April 2013 to April 2014, C4D activities were implemented as part of provincial immunization programs in the Inner Mongolia, Guangxi, Chongqing, Guizhou, Tibet, Shaanxi, Gansu, Ningxia, and Qinghai provinces. We used a before-and-after study design and employed face-to-face interviews to assess changes in parental knowledge and vaccination coverage. We surveyed 2 107 households at baseline and 2 070 households after 1 year of C4D activities. Following C4D, 95% of caregivers were aware of the vaccination record check requirement for entry into kindergarten and primary school; 80% of caregivers were aware that migrant children were eligible for free vaccination; more than 70% of caregivers knew that measles is a respiratory infectious disease; and 90% of caregivers knew the symptoms of measles. Caregivers' willingness to take their children to the clinic for vaccination increased from 51.3% at baseline to 67.4% in the post-C4D survey. Coverage of one-dose measles-containing vaccine (MCV) increased from 83.8% at baseline to 90.1% after C4D. One-dose MCV coverage was greater than 95% in the Guangxi, Shaanxi, and Gansu provinces. Two-dose MCV coverage increased from 68.5 to 77.6%. House-to-house communication was the most popular C4D activity among caregivers (91.6% favoring), followed by posters and educational talks (64.8 and 49.9% favoring). C4D is associated with increased caregiver knowledge about measles, increased willingness to seek immunization services for their children, and increased measles vaccination coverage. Tailored communication strategies based on insights gained from these analyses may be able to increase vaccination coverage in hard-to-reach areas. C4D should be considered for larger scale implementation in China.
Montgomery, Ann L; Fadel, Shaza; Kumar, Rajesh; Bondy, Sue; Moineddin, Rahim; Jha, Prabhat
2014-01-01
Research in areas of low skilled attendant coverage found that maternal mortality is paradoxically higher in women who seek obstetric care. We estimated the effect of health-facility admission on maternal survival, and how this effect varies with skilled attendant coverage across India. Using unmatched population-based case-control analysis of national datasets, we compared the effect of health-facility admission at any time (antenatal, intrapartum, postpartum) on maternal deaths (cases) to women reporting pregnancies (controls). Probability of maternal death decreased with increasing skilled attendant coverage, among both women who were and were not admitted to a health-facility, however, the risk of death among women who were admitted was higher (at 50% coverage, OR = 2.32, 95% confidence interval 1.85-2.92) than among those women who were not; while at higher levels of coverage, the effect of health-facility admission was attenuated. In a secondary analysis, the probability of maternal death decreased with increasing coverage among both women admitted for delivery or delivered at home but there was no effect of admission for delivery on mortality risk (50% coverage, OR = 1.0, 0.80-1.25), suggesting that poor quality of obstetric care may have attenuated the benefits of facility-based care. Subpopulation analysis of obstetric hemorrhage cases and report of 'excessive bleeding' in controls showed that the probability of maternal death decreased with increasing skilled attendant coverage; but the effect of health-facility admission was attenuated (at 50% coverage, OR = 1.47, 0.95-1.79), suggesting that some of the effect in the main model can be explained by women arriving at facility with complications underway. Finally, highest risk associated with health-facility admission was clustered in women with education ≤ 8 years. The effect of health-facility admission did vary by skilled attendant coverage, and this effect appears to be driven partially by reverse causality; however, inequitable access to and possibly poor quality of healthcare for primary and emergency services appears to play a role in maternal survival as well.
Roles of Mo Surface Dopants in Enhancing the ORR Performance of Octahedral PtNi Nanoparticles
Jia, Qingying; Zhao, Zipeng; Cao, Liang; ...
2017-12-22
Doping with a transition metal was recently shown to greatly boost the activity and durability of PtNi/C octahedral nanoparticles (NPs) for the oxygen reduction reaction (ORR), but its specific roles remain unclear. By combining electrochemistry, ex situ and in situ spectroscopic techniques, density functional theory calculations, and a newly developed kinetic Monte Carlo model, we showed that Mo atoms are preferentially located on the vertex and edge sites of Mo–PtNi/C in the form of oxides, which are stable within the wide potential window of the electrochemical cycle. These surface Mo oxides stabilize adjacent Pt sites, hereby stabilizing the octahedral shapemore » enriched with (111) facets, and lead to increased concentration of Ni in subsurface layers where they are protected against acid dissolution. Consequently, the favorable Pt 3Ni(111) structure for the ORR is stabilized on the surface of PtNi/C NPs in acid against voltage cycling. Significantly, the unusual potential-dependent oxygen coverage trend on Mo-doped PtNi/C NPs as revealed by the surface-sensitive Δμ analysis suggests that the Mo dopants may also improve the ORR kinetics by modifying the coordination environments of Pt atoms on the surface. Lastly, our studies point out a possible way to stabilize the favorable shape and composition established on conceptual catalytic models in practical nanoscale catalysts.« less
Mohedano, R A; Costa, R H R; Hofmann, S M; Belli Filho, P
2014-01-01
The rapid increase in the number of swine has caused pronounced environmental impacts worldwide, especially on water resources. As an aggregate, smallholdings have an important role in South American pork production, contributing to the net diffusion of pollution. Thus, duckweed ponds have been successfully used for swine waste polishing, mainly for nutrient removal. Few studies have been carried out to assess organic matter degradation in duckweed ponds. Hence, the present study evaluated the efficiency of two full-scale duckweed ponds for organic matter reduction of swine waste on small pig farms. Duckweed ponds, in series, received the effluent after an anaerobic biodigester and storage pond, with a flow rate of 1 m(3) day(-1). After 1 year of monitoring, an improvement in effluent quality was observed, with a reduction in biochemical oxygen demand (BOD) and total chemical oxygen demand (tCOD), respectively, of 94.8 and 96.7%, operating at a loading rate of approximately 27 kgBOD ha(-1) day(-1) and 131 kgCOD ha(-1) day(-1). Algae inhibition due to duckweed coverage was strongly observed in the pond effluent, where chlorophyll a and turbidity remained below 25 μg L(-1) and 10 NTU. Using the study conditions described herein, duckweed ponds were shown to be a suitable technology for swine waste treatment, contributing to the environmental sustainability of rural areas.
Lee, Nancy Y.; Le, Quynh-Thu
2008-01-01
Intensity modulated radiation therapy (IMRT) has revolutionized radiation treatment for head and neck cancers (HNC). When compared to the traditional techniques, IMRT has the unique ability to minimize the dose delivered to normal tissues without compromising tumor coverage. As a result, side effects from high dose radiation have decreased and patient quality of life has improved. In addition to toxicity reduction, excellent clinical outcomes have been reported for IMRT. The first part of this review will focus on clinical results of IMRT for HNC. Tumor hypoxia or the condition of low oxygen is a key factor for tumor progression and treatment resistance. Hypoxia develops in solid tumors due to aberrant blood vessel formation, fluctuation in blood flow and increasing oxygen demands for tumor growth. Because hypoxic tumor cells are more resistant to ionizing radiation, hypoxia has been a focus of clinical research in radiation therapy for half a decade. Interest for targeting tumor hypoxia have waxed and waned as promising treatments emerged from the laboratory, only to fail in the clinics. However, with the development of new technologies, the prospect of targeting tumor hypoxia is more tangible. The second half of the review will focus on approaches for assessing tumor hypoxia and on the strategies for targeting this important microenvironmental factor in HNC. PMID:18544439
Roles of Mo Surface Dopants in Enhancing the ORR Performance of Octahedral PtNi Nanoparticles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jia, Qingying; Zhao, Zipeng; Cao, Liang
Doping with a transition metal was recently shown to greatly boost the activity and durability of PtNi/C octahedral nanoparticles (NPs) for the oxygen reduction reaction (ORR), but its specific roles remain unclear. By combining electrochemistry, ex situ and in situ spectroscopic techniques, density functional theory calculations, and a newly developed kinetic Monte Carlo model, we showed that Mo atoms are preferentially located on the vertex and edge sites of Mo–PtNi/C in the form of oxides, which are stable within the wide potential window of the electrochemical cycle. These surface Mo oxides stabilize adjacent Pt sites, hereby stabilizing the octahedral shapemore » enriched with (111) facets, and lead to increased concentration of Ni in subsurface layers where they are protected against acid dissolution. Consequently, the favorable Pt 3Ni(111) structure for the ORR is stabilized on the surface of PtNi/C NPs in acid against voltage cycling. Significantly, the unusual potential-dependent oxygen coverage trend on Mo-doped PtNi/C NPs as revealed by the surface-sensitive Δμ analysis suggests that the Mo dopants may also improve the ORR kinetics by modifying the coordination environments of Pt atoms on the surface. Lastly, our studies point out a possible way to stabilize the favorable shape and composition established on conceptual catalytic models in practical nanoscale catalysts.« less
The need for and cost of mandating private insurance coverage of contraception.
Gold, R B
1998-08-01
A public policy debate in the US is considering whether it is in the public interest to mandate that private, employment-related health insurance plans cover contraception. Industry representatives oppose mandates as unnecessary and costly, but women's health advocates point out that mandates were necessary to remove other health insurance disadvantages to women. For example, the Pregnancy Discrimination Act of 1978 was necessary to mandate coverage for maternity care. US women rely on contraception to avoid pregnancy for approximately 20 years during their reproductive lives, but health insurance policies vary widely in the amount of contraceptive coverage provided. Some fail to cover contraception but cover sterilization and abortion. Coverage is important because women cite cost as a consideration when choosing a method, and some of the more effective methods are more costly. Estimates show that the cost of covering the full range of approved reversible contraception would be a minimal $21.40/employee/year, of which employers would pay $17.12, a 0.6% increase in costs. The cost of plans that already cover some reversible methods would increase even less. Public opinion overwhelmingly favors mandated contraception coverage, even if employee costs were to increase. Congress is considering legislation to mandate coverage in private, employment-related plans, and the industry has indicated that it will not fight the legislation.
Hatch, Brigit; Bailey, Steffani R; Cowburn, Stuart; Marino, Miguel; Angier, Heather; DeVoe, Jennifer E
2016-04-01
To assess longitudinal patterns of community health center (CHC) utilization and the effect of insurance discontinuity after Oregon's 2008 Medicaid expansion (the Oregon Experiment). We conducted a retrospective cohort study with electronic health records and Medicaid data. We divided individuals who gained Medicaid in the Oregon Experiment into those who maintained (n = 788) or lost (n = 944) insurance coverage. We compared these groups with continuously insured (n = 921) and continuously uninsured (n = 5416) reference groups for community health center utilization rates over a 36-month period. Both newly insured groups increased utilization in the first 6 months. After 6 months, use among those who maintained coverage stabilized at a level consistent with the continuously insured, whereas it returned to baseline for those who lost coverage. Individuals who maintained coverage through Oregon's Medicaid expansion increased long-term utilization of CHCs, whereas those with unstable coverage did not. This study predicts long-term increase in CHC utilization following Affordable Care Act Medicaid expansion and emphasizes the need for policies that support insurance retention.
Universal health coverage in Latin American countries: how to improve solidarity-based schemes.
Titelman, Daniel; Cetrángolo, Oscar; Acosta, Olga Lucía
2015-04-04
In this Health Policy we examine the association between the financing structure of health systems and universal health coverage. Latin American health systems encompass a wide range of financial sources, which translate into different solidarity-based schemes that combine contributory (payroll taxes) and non-contributory (general taxes) sources of financing. To move towards universal health coverage, solidarity-based schemes must heavily rely on countries' capacity to increase public expenditure in health. Improvement of solidarity-based schemes will need the expansion of mandatory universal insurance systems and strengthening of the public sector including increased fiscal expenditure. These actions demand a new model to integrate different sources of health-sector financing, including general tax revenue, social security contributions, and private expenditure. The extent of integration achieved among these sources will be the main determinant of solidarity and universal health coverage. The basic challenges for improvement of universal health coverage are not only to spend more on health, but also to reduce the proportion of out-of-pocket spending, which will need increased fiscal resources. Copyright © 2015 Elsevier Ltd. All rights reserved.
Selby, Peter; Brosky, Gerald; Oh, Paul; Raymond, Vincent; Arteaga, Carmen; Ranger, Suzanne
2014-05-07
Many smokers find the cost of smoking cessation medications a barrier. Financial coverage for these medications increases utilization of pharmacotherapies. This study assesses whether financial coverage increases the proportion of successful quitters. A pragmatic, open-label, randomized, controlled trial was conducted in 58 Canadian sites between March 2009 and September 2010. Smokers (≥10 cigarettes/day) without insurance coverage who were motivated to quit within 14 days were randomized (1:1) in a blinded manner to receive either full coverage eligibility for 26 weeks or no coverage. Pharmacotherapies covered were varenicline, bupropion, or nicotine patches/gum. Investigators/subjects were unblinded to study group assignment after randomization and prior to choosing a smoking cessation method(s). All subjects received brief smoking cessation counseling. The primary outcome measure was self-reported 7-day point prevalence of abstinence (PPA) at week 26. Of the 1380 randomized subjects (coverage, 696; no coverage, 684), 682 (98.0%) and 435 (63.6%), respectively, were dispensed at least one smoking cessation medication dose. The 7-day PPA at week 26 was higher in the full coverage versus no coverage group: 20.8% (n = 145) and 13.9% (n = 95), respectively; odds ratio (OR) = 1.64, 95% confidence interval (CI) 1.23-2.18; p = 0.001. Urine cotinine-confirmed 7-day PPA at week 26 was 15.7% (n = 109) and 10.1% (n = 69), respectively; OR = 1.68, 95% CI 1.21-2.33; p = 0.002. After pharmacotherapy, coverage eligibility was withdrawn from the full coverage group, continuous abstinence between weeks 26 and 52 was 6.6% (n = 46) and 5.6% (n = 38), in the full coverage and no coverage groups, respectively; OR = 1.19, 95% CI 0.76-1.87; p = 0.439. In this study, the adoption of a smoking cessation medication coverage drug policy was an effective intervention to improve 26-week quit rates in Canada. The advantages were lost once coverage was discontinued. Further study is required on the duration of coverage to prevent relapse to smoking. (clinicaltrials.gov identifier: NCT00818207; the study was sponsored by Pfizer Inc.).
2014-01-01
Background Extra-corporeal membrane oxygenation has been introduced to clinical practice for several decades. It is unclear how internet and newspapers portray the use of extra-corporeal membrane oxygenation. This study were: (1) to quantify the coverage of extra-corporeal membrane oxygenation use in newspapers and on the Internet; (2) to describe the characteristics of extra-corporeal membrane oxygenation users presented in newspaper articles and the Internet web pages in comparison with those shown in extra-corporeal membrane oxygenation studies in Taiwan; and (3) to examine the survival rates of extra-corporeal membrane oxygenation users presented in newspaper articles and the Internet web pages in comparison with those in Taiwan and in the Extracorporeal Life Support Registry Report International Summary for January 2014. Methods All issues of Taiwan’s four major newspapers from 2006 to 2010 were reviewed. In October 2011, a search of Internet web pages was performed based on the subjects of “yeh-ko-mo” (extra-corporeal membrane oxygenation in Traditional Chinese), “ECMO”, and “extra-corporeal membrane oxygenation.” All the Internet web pages and newspaper articles recounting the use of extra-corporeal membrane oxygenation were reviewed. The information, such as patient characteristic and the status at hospital discharge, was collected. Results The survival rate of extra-corporeal membrane oxygenation use shown on the Internet (83.97%) was significantly higher than all the survival rates reported in Taiwan’s literature (p < .01) and in the Extracorporeal Life Support Registry Report International Summary for January 2014 (p < .01). In addition, the survival rate of extra-corporeal membrane oxygenation use shown in newspapers (61.54%) was significantly higher than the average survival rate (43%) reported in Taiwan’s literature, the pediatric average survival rate (51%), and the adult average survival rate (47%) in the Extracorporeal Life Support Registry Report International Summary for January 2014. Conclusions Internet and newspapers both showed over-optimistic survival to hospital discharge for patients sustained by extra-corporeal membrane oxygenation. Internet was more likely to provide optimistic information for aggressive life-supporting treatments such as extra-corporeal membrane oxygenation than newspapers as indicated by survival to hospital discharge. PMID:25081491
Elucidation of Active Sites for the Reaction of Ethanol on TiO 2 /Au(111)
Boyle, David T.; Wilke, Jeremy A.; Palomino, Robert M.; ...
2017-03-17
Obtaining a molecular-level understanding of the reaction of alcohols with heterogeneous model catalysts is critical for improving industrial catalytic processes, such as the production of H 2 from alcohols. Gold has been shown to be an excellent oxidation catalyst once oxygen is added to it. The use of reducible oxides provides a source of oxygen on Au(111) for the reaction of ethanol, which is easily regenerated in the presence of an oxygen background. In this work, ethanol operates as a probe molecule to investigate the role of Au(111), TiO 2 nanoparticles, and TiO 2/Au interfacial surface sites on the catalyticmore » properties of TiO 2/Au(111). Ultrahigh vacuum temperature-programmed desorption (TPD) studies with ethanol/Au(111) elucidate previously unreported adsorption sites for ethanol. Ethanol molecularly adsorbs to Au terrace sites, step edges, and undercoordinated kink sites with adsorption energies of -51.7, -55.8, and -65.1 kJ/mol, respectively. In a TPD coverage study of ethanol on TiO 2/Au(111) indicates ethanol undergoes dissociative adsorption to form H*(a) and CH 3CH 2O*(a) on the inverse model catalyst surface. The desorption temperature of low coverages of ethanol from TiO2/Au(111) (Tdes ≈ 235 K) is at an intermediate temperature between the desorption temperatures from bulk Au(111) and TiO 2(110), indicating both Au and TiO 2 play a role in the adsorption of ethanol. Both low-temperature adsorption and high-temperature reactions are studied and indicate that ethanol-derived products such as acetaldehyde and ethylene desorb from TiO 2/Au(111) at ~500 K. Here, we report the identification of catalytically active sites on TiO 2/Au(111) as interfacial sites between the oxide and Au(111) surface through the use of temperature-programmed desorption and infrared reflection absorption spectroscopy.« less
Elucidation of Active Sites for the Reaction of Ethanol on TiO 2 /Au(111)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boyle, David T.; Wilke, Jeremy A.; Palomino, Robert M.
Obtaining a molecular-level understanding of the reaction of alcohols with heterogeneous model catalysts is critical for improving industrial catalytic processes, such as the production of H 2 from alcohols. Gold has been shown to be an excellent oxidation catalyst once oxygen is added to it. The use of reducible oxides provides a source of oxygen on Au(111) for the reaction of ethanol, which is easily regenerated in the presence of an oxygen background. In this work, ethanol operates as a probe molecule to investigate the role of Au(111), TiO 2 nanoparticles, and TiO 2/Au interfacial surface sites on the catalyticmore » properties of TiO 2/Au(111). Ultrahigh vacuum temperature-programmed desorption (TPD) studies with ethanol/Au(111) elucidate previously unreported adsorption sites for ethanol. Ethanol molecularly adsorbs to Au terrace sites, step edges, and undercoordinated kink sites with adsorption energies of -51.7, -55.8, and -65.1 kJ/mol, respectively. In a TPD coverage study of ethanol on TiO 2/Au(111) indicates ethanol undergoes dissociative adsorption to form H*(a) and CH 3CH 2O*(a) on the inverse model catalyst surface. The desorption temperature of low coverages of ethanol from TiO2/Au(111) (Tdes ≈ 235 K) is at an intermediate temperature between the desorption temperatures from bulk Au(111) and TiO 2(110), indicating both Au and TiO 2 play a role in the adsorption of ethanol. Both low-temperature adsorption and high-temperature reactions are studied and indicate that ethanol-derived products such as acetaldehyde and ethylene desorb from TiO 2/Au(111) at ~500 K. Here, we report the identification of catalytically active sites on TiO 2/Au(111) as interfacial sites between the oxide and Au(111) surface through the use of temperature-programmed desorption and infrared reflection absorption spectroscopy.« less
Universal health coverage in Turkey: enhancement of equity.
Atun, Rifat; Aydın, Sabahattin; Chakraborty, Sarbani; Sümer, Safir; Aran, Meltem; Gürol, Ipek; Nazlıoğlu, Serpil; Ozgülcü, Senay; Aydoğan, Ulger; Ayar, Banu; Dilmen, Uğur; Akdağ, Recep
2013-07-06
Turkey has successfully introduced health system changes and provided its citizens with the right to health to achieve universal health coverage, which helped to address inequities in financing, health service access, and health outcomes. We trace the trajectory of health system reforms in Turkey, with a particular emphasis on 2003-13, which coincides with the Health Transformation Program (HTP). The HTP rapidly expanded health insurance coverage and access to health-care services for all citizens, especially the poorest population groups, to achieve universal health coverage. We analyse the contextual drivers that shaped the transformations in the health system, explore the design and implementation of the HTP, identify the factors that enabled its success, and investigate its effects. Our findings suggest that the HTP was instrumental in achieving universal health coverage to enhance equity substantially, and led to quantifiable and beneficial effects on all health system goals, with an improved level and distribution of health, greater fairness in financing with better financial protection, and notably increased user satisfaction. After the HTP, five health insurance schemes were consolidated to create a unified General Health Insurance scheme with harmonised and expanded benefits. Insurance coverage for the poorest population groups in Turkey increased from 2·4 million people in 2003, to 10·2 million in 2011. Health service access increased across the country-in particular, access and use of key maternal and child health services improved to help to greatly reduce the maternal mortality ratio, and under-5, infant, and neonatal mortality, especially in socioeconomically disadvantaged groups. Several factors helped to achieve universal health coverage and improve outcomes. These factors include economic growth, political stability, a comprehensive transformation strategy led by a transformation team, rapid policy translation, flexible implementation with continuous learning, and simultaneous improvements in the health system, on both the demand side (increased health insurance coverage, expanded benefits, and reduced cost-sharing) and the supply side (expansion of infrastructure, health human resources, and health services). Copyright © 2013 Elsevier Ltd. All rights reserved.
Park, Elyse R; Kirchhoff, Anne C; Perez, Giselle K; Leisenring, Wendy; Weissman, Joel S; Donelan, Karen; Mertens, Ann C; Reschovsky, James D; Armstrong, Gregory T; Robison, Leslie L; Franklin, Mariel; Hyland, Kelly A; Diller, Lisa R; Recklitis, Christopher J; Kuhlthau, Karen A
2015-03-01
The Patient Protection and Affordable Care Act (ACA) established provisions intended to increase access to affordable health insurance and thus increase access to medical care and long-term surveillance for populations with pre-existing conditions. However, childhood cancer survivors' coverage priorities and familiarity with the ACA are unknown. Between May 2011 and April 2012, we surveyed a randomly selected, age-stratified sample of 698 survivors and 210 siblings from the Childhood Cancer Survivor Study. Overall, 89.8% of survivors and 92.1% of siblings were insured. Many features of insurance coverage that survivors considered "very important" are addressed by the ACA, including increased availability of primary care (94.6%), no waiting period before coverage initiation (79.0%), and affordable premiums (88.1%). Survivors were more likely than siblings to deem primary care physician coverage and choice, protections from costs due to pre-existing conditions, and no start-up period as "very important" (P < .05 for all). Only 27.3% of survivors and 26.2% of siblings reported familiarity with the ACA (12.1% of uninsured v 29.0% of insured survivors; odds ratio, 2.86; 95% CI, 1.28 to 6.36). Only 21.3% of survivors and 18.9% of siblings believed the ACA would make it more likely that they would get quality coverage. Survivors' and siblings' concerns about the ACA included increased costs, decreased access to and quality of care, and negative impact on employers and employees. Although survivors' coverage preferences match many ACA provisions, survivors, particularly uninsured survivors, were not familiar with the ACA. Education and assistance, perhaps through cancer survivor navigation, are critically needed to ensure that survivors access coverage and benefits. © 2015 by American Society of Clinical Oncology.
Park, Elyse R.; Kirchhoff, Anne C.; Perez, Giselle K.; Leisenring, Wendy; Weissman, Joel S.; Donelan, Karen; Mertens, Ann C.; Reschovsky, James D.; Armstrong, Gregory T.; Robison, Leslie L.; Franklin, Mariel; Hyland, Kelly A.; Diller, Lisa R.; Recklitis, Christopher J.; Kuhlthau, Karen A.
2015-01-01
Purpose The Patient Protection and Affordable Care Act (ACA) established provisions intended to increase access to affordable health insurance and thus increase access to medical care and long-term surveillance for populations with pre-existing conditions. However, childhood cancer survivors' coverage priorities and familiarity with the ACA are unknown. Methods Between May 2011 and April 2012, we surveyed a randomly selected, age-stratified sample of 698 survivors and 210 siblings from the Childhood Cancer Survivor Study. Results Overall, 89.8% of survivors and 92.1% of siblings were insured. Many features of insurance coverage that survivors considered “very important” are addressed by the ACA, including increased availability of primary care (94.6%), no waiting period before coverage initiation (79.0%), and affordable premiums (88.1%). Survivors were more likely than siblings to deem primary care physician coverage and choice, protections from costs due to pre-existing conditions, and no start-up period as “very important” (P < .05 for all). Only 27.3% of survivors and 26.2% of siblings reported familiarity with the ACA (12.1% of uninsured v 29.0% of insured survivors; odds ratio, 2.86; 95% CI, 1.28 to 6.36). Only 21.3% of survivors and 18.9% of siblings believed the ACA would make it more likely that they would get quality coverage. Survivors' and siblings' concerns about the ACA included increased costs, decreased access to and quality of care, and negative impact on employers and employees. Conclusion Although survivors' coverage preferences match many ACA provisions, survivors, particularly uninsured survivors, were not familiar with the ACA. Education and assistance, perhaps through cancer survivor navigation, are critically needed to ensure that survivors access coverage and benefits. PMID:25646189
Increased sediment oxygen flux in lakes and reservoirs: The impact of hypolimnetic oxygenation
NASA Astrophysics Data System (ADS)
Bierlein, Kevin A.; Rezvani, Maryam; Socolofsky, Scott A.; Bryant, Lee D.; Wüest, Alfred; Little, John C.
2017-06-01
Hypolimnetic oxygenation is an increasingly common lake management strategy for mitigating hypoxia/anoxia and associated deleterious effects on water quality. A common effect of oxygenation is increased oxygen consumption in the hypolimnion and predicting the magnitude of this increase is the crux of effective oxygenation system design. Simultaneous measurements of sediment oxygen flux (JO2) and turbulence in the bottom boundary layer of two oxygenated lakes were used to investigate the impact of oxygenation on JO2. Oxygenation increased JO2 in both lakes by increasing the bulk oxygen concentration, which in turn steepens the diffusive gradient across the diffusive boundary layer. At high flow rates, the diffusive boundary layer thickness decreased as well. A transect along one of the lakes showed JO2 to be spatially quite variable, with near-field and far-field JO2 differing by a factor of 4. Using these in situ measurements, physical models of interfacial flux were compared to microprofile-derived JO2 to determine which models adequately predict JO2 in oxygenated lakes. Models based on friction velocity, turbulence dissipation rate, and the integral scale of turbulence agreed with microprofile-derived JO2 in both lakes. These models could potentially be used to predict oxygenation-induced oxygen flux and improve oxygenation system design methods for a broad range of reservoir systems.
Coverage dependent non-adiabaticity of CO on a copper surface
DOE Office of Scientific and Technical Information (OSTI.GOV)
Omiya, Takuma; Surface and Interface Science Laboratory, RIKEN, Wako 351-0198; Arnolds, Heike
2014-12-07
We have studied the coverage-dependent energy transfer dynamics between hot electrons and CO on Cu(110) with femtosecond visible pump, sum frequency probe spectroscopy. We find that transients of the C–O stretch frequency display a red shift, which increases from 3 cm{sup −1} at 0.1 ML to 9 cm{sup −1} at 0.77 ML. Analysis of the transients reveals that the non-adiabatic coupling between the adsorbate vibrational motion and the electrons becomes stronger with increasing coverage. This trend requires the frustrated rotational mode to be the cause of the non-adiabatic behavior, even for relatively weak laser excitation of the adsorbate. We attributemore » the coverage dependence to both an increase in the adsorbate electronic density of states and an increasingly anharmonic potential energy surface caused by repulsive interactions between neighboring CO adsorbates. This work thus reveals adsorbate-adsorbate interactions as a new way to control adsorbate non-adiabaticity.« less
Zong, Ning; Chai, Xi; Shi, Pei Li; Jiang, Jing; Niu, Ben; Zhang, Xian Zhou; He, Yong Tao
2016-12-01
Global climate warming and increasing nitrogen (N) deposition, as controversial global environmental issues, may distinctly affect the functions and processes of terrestrial ecosystems. It has been reported that the Qinghai-Tibet Plateau has been experiencing significant warming in recent decades, especially in winter. Previous studies have mainly focused on the effects of warming all the year round; however, few studies have tested the effects of winter warming. To investigate the effects of winter warming and N addition on plant community structure and species composition of alpine meadow, long-term N addition and simulated warming experiment was conducted in alpine meadow from 2010 in Damxung, northern Tibet. The experiment consisted of three warming patterns: Year-round warming (YW), winter warming (WW) and control (NW), crossed respectively with five N gradients: 0, 10, 20, 40, 80 kg N·hm -2 ·a -1 . From 2012 to 2014, both warming and N addition significantly affected the total coverage of plant community. Specifically, YW significantly decreased the total coverage of plant community. Without N addition, WW remarkably reduced the vegetation coverage. However, with N addition, the total vegetation coverage gradually increased with the increase of N level. Warming and N addition had different effects on plants from different functional groups. Warming significantly reduced the plant coverage of grasses and sedges, while N addition significantly enhanced the plant coverage of grasses. Regression analyses showed that the total coverage of plant community was positively related to soil water content in vigorous growth stages, indicating that the decrease in soil water content resulted from warming during dry seasons might be the main reason for the decline of total community coverage. As soil moisture in semi-arid alpine meadow is mainly regulated by rainfalls, our results indicated that changes in spatial and temporal patterns of rainfalls under the future climate change scenarios would dramatically influence the vegetation coverage and species composition. Additionally, the effects of increasing atmospheric N deposition on vegetation community might also depend on the change of rainfall patterns.
Alton, Lesley A; Portugal, Steven J; White, Craig R
2013-02-01
Air-breathing fish of the Anabantoidei group meet their metabolic requirements for oxygen through both aerial and aquatic gas exchange. Siamese fighting fish Betta splendens are anabantoids that frequently engage in aggressive male-male interactions which cause significant increases in metabolic rate and oxygen requirements. These interactions involve opercular flaring behaviour that is thought to limit aquatic oxygen uptake, and combines with the increase in metabolic rate to cause an increase in air-breathing behaviour. Air-breathing events interrupt display behaviour and increase risk of predation, raising the question of how Siamese fighting fish manage their oxygen requirements during agonistic encounters. Using open-flow respirometry, we measured rate of oxygen consumption in displaying fish to determine if males increase oxygen uptake per breath to minimise visits to the surface, or increase their reliance on aquatic oxygen uptake. We found that the increased oxygen requirements of Siamese fighting fish during display behaviour were met by increased oxygen uptake from the air with no significant changes in aquatic oxygen uptake. The increased aerial oxygen uptake was achieved almost entirely by an increase in air-breathing frequency. We conclude that limitations imposed by the reduced gill surface area of air-breathing fish restrict the ability of Siamese fighting fish to increase aquatic uptake, and limitations of the air-breathing organ of anabantoids largely restrict their capacity to increase oxygen uptake per breath. The resulting need to increase surfacing frequency during metabolically demanding agonistic encounters has presumably contributed to the evolution of the stereotyped surfacing behaviour seen during male-male interactions, during which one of the fish will lead the other to the surface, and each will take a breath of air. Copyright © 2012. Published by Elsevier Inc.
Lumb, Andrew B; Nair, Sindhu
2010-03-01
Breathing increased fractional oxygen concentration (FiO2) is recommended for the treatment of tissue ischaemia. The theoretical benefits of increasing FiO2 on tissue oxygenation were evaluated using standard physiological equations. Assuming constant oxygen consumption by tissues throughout the length of a capillary, the oxygen content at 20 arbitrary points along a capillary was calculated. Using mathematical representations of the haemoglobin dissociation curve and an iterative approach to include the dissolved oxygen component of oxygen content, the oxygen partial pressure (PO2) profile along a capillary was estimated. High FiO2 concentrations cause large increases in PO2 at the arteriolar end of capillaries but these large PO2 values, caused by the extra dissolved oxygen, rapidly decline along the capillary. At the venular end of the capillary (the area of tissue most likely to be hypoxic), breathing oxygen causes only a modest improvement in PO2. Increasing FiO2 to treat tissue hypoxia has clear benefits, but a multimodal approach to management is required.
Covered today, sick tomorrow? Trends and correlates of children's health insurance instability.
Hill, Heather D; Shaefer, H Luke
2011-10-01
Many children with health insurance will experience gaps in coverage over time, potentially reducing their access to and use of preventive health care services. This article uses the Survey of Income and Program Participation to examine how the stability of children's health insurance changed between 1990 and 2005 and to identify dynamic aspects of family life associated with transitions in coverage. Children's health insurance instability has increased since the early 1990s, due to greater movement between insured and uninsured states and between private and public insurance coverage. Changes in the employment and marital status of the family head are highly associated with an increased risk of a child losing and gaining public and private coverage, largely in hypothesized directions. The exception is that marital dissolution and job loss are associated with an increased probability of a child losing public insurance, despite there being no clear policy explanation for such a relationship.
Trends in Childhood Influenza Vaccination Coverage—U.S., 2004–2012
Lu, Peng-Jun; O'Halloran, Alissa; Meghani, Ankita; Grabowsky, Mark; Singleton, James A.
2014-01-01
Objective We compared estimates of childhood influenza vaccination coverage by health status, age, and racial/ethnic group across eight consecutive influenza seasons (2004 through 2012) based on two survey systems to assess trends in childhood influenza vaccination coverage in the U.S. Methods We used National Health Interview Survey (NHIS) and National Immunization Survey-Flu (NIS-Flu) data to estimate receipt of at least one dose of influenza vaccination among children aged 6 months to 17 years based on parental report. We computed estimates using Kaplan-Meier survival analysis methods. Results Based on the NHIS, overall influenza vaccination coverage with at least one dose of influenza vaccine among children increased from 16.2% during the 2004–2005 influenza season to 47.1% during the 2011–2012 influenza season. Children with health conditions that put them at high risk for complications from influenza had higher influenza vaccination coverage than children without these health conditions for all the seasons studied. In seven of the eight seasons studied, there were no significant differences in influenza vaccination coverage between non-Hispanic black and non-Hispanic white children. Influenza vaccination coverage estimates for children were slightly higher based on NIS-Flu data compared with NHIS data for the 2010–2011 and 2011–2012 influenza seasons (4.1 and 4.4 percentage points higher, respectively); both NIS-Flu and NHIS estimates had similar patterns of decreasing vaccination coverage with increasing age. Conclusions Although influenza vaccination coverage among children continued to increase, by the 2011–2012 influenza season, only slightly less than half of U.S. children were vaccinated against influenza. Much improvement is needed to ensure all children aged ≥6 months are vaccinated annually against influenza. PMID:25177053
Surveillance of Vaccination Coverage among Adult Populations - United States, 2015.
Williams, Walter W; Lu, Peng-Jun; O'Halloran, Alissa; Kim, David K; Grohskopf, Lisa A; Pilishvili, Tamara; Skoff, Tami H; Nelson, Noele P; Harpaz, Rafael; Markowitz, Lauri E; Rodriguez-Lainz, Alfonso; Fiebelkorn, Amy Parker
2017-05-05
Overall, the prevalence of illness attributable to vaccine-preventable diseases is greater among adults than among children. Adults are recommended to receive vaccinations based on their age, underlying medical conditions, lifestyle, prior vaccinations, and other considerations. Updated vaccination recommendations from CDC are published annually in the U.S. Adult Immunization Schedule. Despite longstanding recommendations for use of many vaccines, vaccination coverage among U.S. adults is low. August 2014-June 2015 (for influenza vaccination) and January-December 2015 (for pneumococcal, tetanus and diphtheria [Td] and tetanus and diphtheria with acellular pertussis [Tdap], hepatitis A, hepatitis B, herpes zoster, and human papillomavirus [HPV] vaccination). The National Health Interview Survey (NHIS) is a continuous, cross-sectional national household survey of the noninstitutionalized U.S. civilian population. In-person interviews are conducted throughout the year in a probability sample of households, and NHIS data are compiled and released annually. The survey objective is to monitor the health of the U.S. population and provide estimates of health indicators, health care use and access, and health-related behaviors. Compared with data from the 2014 NHIS, increases in vaccination coverage occurred for influenza vaccine among adults aged ≥19 years (a 1.6 percentage point increase compared with the 2013-14 season to 44.8%), pneumococcal vaccine among adults aged 19-64 years at increased risk for pneumococcal disease (a 2.8 percentage point increase to 23.0%), Tdap vaccine among adults aged ≥19 years and adults aged 19-64 years (a 3.1 percentage point and 3.3 percentage point increase to 23.1% and to 24.7%, respectively), herpes zoster vaccine among adults aged ≥60 years and adults aged ≥65 years (a 2.7 percentage point and 3.2 percentage point increase to 30.6% and to 34.2%, respectively), and hepatitis B vaccine among health care personnel (HCP) aged ≥19 years (a 4.1 percentage point increase to 64.7%). Herpes zoster vaccination coverage in 2015 met the Healthy People 2020 target of 30%. Aside from these modest improvements, vaccination coverage among adults in 2015 was similar to estimates from 2014. Racial/ethnic differences in coverage persisted for all seven vaccines, with higher coverage generally for whites compared with most other groups. Adults without health insurance reported receipt of influenza vaccine (all age groups), pneumococcal vaccine (adults aged 19-64 years at increased risk), Td vaccine (adults aged ≥19 years, 19-64 years, and 50-64 years), Tdap vaccine (adults aged ≥19 years and 19-64 years), hepatitis A vaccine (adults aged ≥19 years overall and among travelers), hepatitis B vaccine (adults aged ≥19 years, 19-49 years, and among travelers), herpes zoster vaccine (adults aged ≥60 years), and HPV vaccine (males and females aged 19-26 years) less often than those with health insurance. Adults who reported having a usual place for health care generally reported receipt of recommended vaccinations more often than those who did not have such a place, regardless of whether they had health insurance. Vaccination coverage was higher among adults reporting one or more physician contacts in the past year compared with those who had not visited a physician in the past year, regardless of whether they had health insurance. Even among adults who had health insurance and ≥10 physician contacts within the past year, depending on the vaccine, 18.2%-85.6% reported not having received vaccinations that were recommended either for all persons or for those with specific indications. Overall, vaccination coverage among U.S.-born adults was higher than that among foreign-born adults, with few exceptions (influenza vaccination [adults aged 19-49 years and 50-64 years], hepatitis A vaccination [adults aged ≥19 years], and hepatitis B vaccination [adults aged ≥19 years with diabetes or chronic liver conditions]). Coverage for all vaccines for adults remained low but modest gains occurred in vaccination coverage for influenza (adults aged ≥19 years), pneumococcal (adults aged 19-64 years with increased risk), Tdap (adults aged ≥19 years and adults aged 19-64 years), herpes zoster (adults aged ≥60 years and ≥65 years), and hepatitis B (HCP aged ≥19 years); coverage for other vaccines and groups with vaccination indications did not improve. The 30% Healthy People 2020 target for herpes zoster vaccination was met. Racial/ethnic disparities persisted for routinely recommended adult vaccines. Missed opportunities to vaccinate remained. Although having health insurance coverage and a usual place for health care were associated with higher vaccination coverage, these factors alone were not associated with optimal adult vaccination coverage. HPV vaccination coverage for males and females has increased since CDC recommended vaccination to prevent cancers caused by HPV, but many adolescents and young adults remained unvaccinated. Assessing factors associated with low coverage rates and disparities in vaccination is important for implementing strategies to improve vaccination coverage. Evidence-based practices that have been demonstrated to improve vaccination coverage should be used. These practices include assessment of patients' vaccination indications by health care providers and routine recommendation and offer of needed vaccines to adults, implementation of reminder-recall systems, use of standing-order programs for vaccination, and assessment of practice-level vaccination rates with feedback to staff members. For vaccination coverage to be improved among those who reported lower coverage rates of recommended adult vaccines, efforts also are needed to identify adults who do not have a regular provider or insurance and who report fewer health care visits.
Surveillance of Vaccination Coverage among Adult Populations — United States, 2015
Lu, Peng-Jun; O’Halloran, Alissa; Kim, David K.; Grohskopf, Lisa A.; Pilishvili, Tamara; Skoff, Tami H.; Nelson, Noele P.; Harpaz, Rafael; Markowitz, Lauri E.; Rodriguez-Lainz, Alfonso; Fiebelkorn, Amy Parker
2017-01-01
Problem/Condition Overall, the prevalence of illness attributable to vaccine-preventable diseases is greater among adults than among children. Adults are recommended to receive vaccinations based on their age, underlying medical conditions, lifestyle, prior vaccinations, and other considerations. Updated vaccination recommendations from CDC are published annually in the U.S. Adult Immunization Schedule. Despite longstanding recommendations for use of many vaccines, vaccination coverage among U.S. adults is low. Period Covered August 2014–June 2015 (for influenza vaccination) and January–December 2015 (for pneumococcal, tetanus and diphtheria [Td] and tetanus and diphtheria with acellular pertussis [Tdap], hepatitis A, hepatitis B, herpes zoster, and human papillomavirus [HPV] vaccination). Description of System The National Health Interview Survey (NHIS) is a continuous, cross-sectional national household survey of the noninstitutionalized U.S. civilian population. In-person interviews are conducted throughout the year in a probability sample of households, and NHIS data are compiled and released annually. The survey objective is to monitor the health of the U.S. population and provide estimates of health indicators, health care use and access, and health-related behaviors. Results Compared with data from the 2014 NHIS, increases in vaccination coverage occurred for influenza vaccine among adults aged ≥19 years (a 1.6 percentage point increase compared with the 2013–14 season to 44.8%), pneumococcal vaccine among adults aged 19–64 years at increased risk for pneumococcal disease (a 2.8 percentage point increase to 23.0%), Tdap vaccine among adults aged ≥19 years and adults aged 19–64 years (a 3.1 percentage point and 3.3 percentage point increase to 23.1% and to 24.7%, respectively), herpes zoster vaccine among adults aged ≥60 years and adults aged ≥65 years (a 2.7 percentage point and 3.2 percentage point increase to 30.6% and to 34.2%, respectively), and hepatitis B vaccine among health care personnel (HCP) aged ≥19 years (a 4.1 percentage point increase to 64.7%). Herpes zoster vaccination coverage in 2015 met the Healthy People 2020 target of 30%. Aside from these modest improvements, vaccination coverage among adults in 2015 was similar to estimates from 2014. Racial/ethnic differences in coverage persisted for all seven vaccines, with higher coverage generally for whites compared with most other groups. Adults without health insurance reported receipt of influenza vaccine (all age groups), pneumococcal vaccine (adults aged 19–64 years at increased risk), Td vaccine (adults aged ≥19 years, 19–64 years, and 50–64 years), Tdap vaccine (adults aged ≥19 years and 19–64 years), hepatitis A vaccine (adults aged ≥19 years overall and among travelers), hepatitis B vaccine (adults aged ≥19 years, 19–49 years, and among travelers), herpes zoster vaccine (adults aged ≥60 years), and HPV vaccine (males and females aged 19–26 years) less often than those with health insurance. Adults who reported having a usual place for health care generally reported receipt of recommended vaccinations more often than those who did not have such a place, regardless of whether they had health insurance. Vaccination coverage was higher among adults reporting one or more physician contacts in the past year compared with those who had not visited a physician in the past year, regardless of whether they had health insurance. Even among adults who had health insurance and ≥10 physician contacts within the past year, depending on the vaccine, 18.2%–85.6% reported not having received vaccinations that were recommended either for all persons or for those with specific indications. Overall, vaccination coverage among U.S.-born adults was higher than that among foreign-born adults, with few exceptions (influenza vaccination [adults aged 19–49 years and 50–64 years], hepatitis A vaccination [adults aged ≥19 years], and hepatitis B vaccination [adults aged ≥19 years with diabetes or chronic liver conditions]). Interpretation Coverage for all vaccines for adults remained low but modest gains occurred in vaccination coverage for influenza (adults aged ≥19 years), pneumococcal (adults aged 19–64 years with increased risk), Tdap (adults aged ≥19 years and adults aged 19–64 years), herpes zoster (adults aged ≥60 years and ≥65 years), and hepatitis B (HCP aged ≥19 years); coverage for other vaccines and groups with vaccination indications did not improve. The 30% Healthy People 2020 target for herpes zoster vaccination was met. Racial/ethnic disparities persisted for routinely recommended adult vaccines. Missed opportunities to vaccinate remained. Although having health insurance coverage and a usual place for health care were associated with higher vaccination coverage, these factors alone were not associated with optimal adult vaccination coverage. HPV vaccination coverage for males and females has increased since CDC recommended vaccination to prevent cancers caused by HPV, but many adolescents and young adults remained unvaccinated. Public Health Actions Assessing factors associated with low coverage rates and disparities in vaccination is important for implementing strategies to improve vaccination coverage. Evidence-based practices that have been demonstrated to improve vaccination coverage should be used. These practices include assessment of patients’ vaccination indications by health care providers and routine recommendation and offer of needed vaccines to adults, implementation of reminder-recall systems, use of standing-order programs for vaccination, and assessment of practice-level vaccination rates with feedback to staff members. For vaccination coverage to be improved among those who reported lower coverage rates of recommended adult vaccines, efforts also are needed to identify adults who do not have a regular provider or insurance and who report fewer health care visits. PMID:28472027
Card, David; Dobkin, Carlos; Maestas, Nicole
2008-12-01
The onset of Medicare eligibility at age 65 leads to sharp changes in the health insurance coverage of the U.S. population. These changes lead to increases in the use of medical services, with a pattern of gains across socioeconomic groups that varies by type of service. While routine doctor visits increase more for groups that previously lacked insurance, hospital admissions for relatively expensive procedures like bypass surgery and joint replacement increase more for previously insured groups that are more likely to have supplementary coverage after 65, reflecting the relative generosity of their combined insurance package under Medicare.
The Impact of Nearly Universal Insurance Coverage on Health Care Utilization: Evidence from Medicare
Dobkin, Carlos; Maestas, Nicole
2008-01-01
The onset of Medicare eligibility at age 65 leads to sharp changes in the health insurance coverage of the U.S. population. These changes lead to increases in the use of medical services, with a pattern of gains across socioeconomic groups that varies by type of service. While routine doctor visits increase more for groups that previously lacked insurance, hospital admissions for relatively expensive procedures like bypass surgery and joint replacement increase more for previously insured groups that are more likely to have supplementary coverage after 65, reflecting the relative generosity of their combined insurance package under Medicare. PMID:19079738
Nonphotosynthetic Pigments as Potential Biosignatures
Cockell, Charles S.; Meadows, Victoria S.
2015-01-01
Abstract Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstrate that, given sufficient surface coverage, nonphotosynthetic pigments could significantly impact the disk-averaged spectrum of a planet. However, we find that due to the possible diversity of organisms and environments, and the confounding effects of the atmosphere and clouds, determination of substantial coverage by biologically produced pigments would be difficult with broadband colors alone and would likely require spectrally resolved data. Key Words: Biosignatures—Exoplanets—Halophiles—Pigmentation—Reflectance spectroscopy—Spectral models. Astrobiology 15, 341–361. PMID:25941875
Friesen, Valerie M; Aaron, Grant J; Myatt, Mark; Neufeld, Lynnette M
2017-05-01
Food fortification is a widely used approach to increase micronutrient intake in the diet. High coverage is essential for achieving impact. Data on coverage is limited in many countries, and tools to assess coverage of fortification programs have not been standardized. In 2013, the Global Alliance for Improved Nutrition developed the Fortification Assessment Coverage Toolkit (FACT) to carry out coverage assessments in both population-based (i.e., staple foods and/or condiments) and targeted (e.g., infant and young child) fortification programs. The toolkit was designed to generate evidence on program coverage and the use of fortified foods to provide timely and programmatically relevant information for decision making. This supplement presents results from FACT surveys that assessed the coverage of population-based and targeted food fortification programs across 14 countries. It then discusses the policy and program implications of the findings for the potential for impact and program improvement.
Coverage and Representations of Sexuality in Introductory Sociology Textbooks
ERIC Educational Resources Information Center
Suarez, Alicia E.; Balaji, Alexandra
2007-01-01
Mirroring increased cultural and disciplinary attention to sexuality, many introductory sociology textbooks have begun to include coverage of the topic. Our study first assesses the extent of textual coverage of sexuality in a sample of 38 introductory textbooks published after 2000. Secondly, we focus on 14 textbooks with a sexuality chapter…
Newspaper Coverage of Biological Subissues in the Spotted Owl Debate, 1989-1993.
ERIC Educational Resources Information Center
Furlow, F. Bryant
1994-01-01
Computer archives for 27 U.S. daily newspapers were accessed to evaluate the levels of coverage for 5 biological subissues and 5 ecological concepts in articles on the spotted owl debate. The author identified a correlation between biologist/reporter contact and increased biological subissue and ecological concepts coverage. (LZ)
Congressional Television: Attempts to Implement Televised Coverage of the U.S. Congress.
ERIC Educational Resources Information Center
Garay, Ronald
In 1970, the Legislative Reorganization Act authorized the U.S. Senate and House of Representatives to open their committee meetings to both radio and television. Three factors increased interest in implementing media coverage of such meetings: feasibility of televised coverage, public cynicism and hostility generated by misinformation and…
Benefit Coverage and Employee Cost: Critical Factors in Explaining Compensation Satisfaction.
ERIC Educational Resources Information Center
Dreher, George F.; And Others
1988-01-01
Examined joint effects of benefit coverage and costs borne by employees on multiple dimensions of compensation satisfaction among 2,925 highway patrol, state police, and department of public safety employees in eight states. Found that satisfaction with benefits increased with improved coverage and decreased with higher employee costs. Employees…
Tran, Linda Diem
2016-12-01
A difference-in-difference approach was used to compare the effects of same-sex domestic partnership, civil union, and marriage policies on same- and different-sex partners who could have benefitted from their partners' employer-based insurance (EBI) coverage. Same-sex partners had 78% lower odds (Marginal Effect = -21%) of having EBI compared with different-sex partners, adjusting for socioeconomic and health-related factors. Same-sex partners living in states that recognized same-sex marriage or domestic partnership had 89% greater odds of having EBI compared with those in states that did not recognize same-sex unions (ME = 5%). The impact of same-sex legislation on increasing take-up of dependent EBI coverage among lesbians, gay men, and bisexual individuals was modest, and domestic partnership legislation was equally as effective as same-sex marriage in increasing same-sex partner EBI coverage. Extending dependent EBI coverage to same-sex partners can mitigate gaps in coverage for a segment of the lesbians, gay men, and bisexual population but will not eliminate them. © The Author(s) 2016.
Increasing Cervical Cancer Screening Coverage: A Randomised, Community-Based Clinical Trial.
Acera, Amelia; Manresa, Josep Maria; Rodriguez, Diego; Rodriguez, Ana; Bonet, Josep Maria; Trapero-Bertran, Marta; Hidalgo, Pablo; Sànchez, Norman; de Sanjosé, Silvia
2017-01-01
Opportunistic cervical cancer screening can lead to suboptimal screening coverage. Coverage could be increased after a personalised invitation to the target population. We present a community randomized intervention study with three strategies aiming to increase screening coverage. The CRICERVA study is a community-based clinical trial to improve coverage of population-based screening in the Cerdanyola SAP area in Barcelona.A total of 32,858 women residing in the study area, aged 30 to 70 years were evaluated. A total of 15,965 women were identified as having no registration of a cervical cytology in the last 3.5 years within the Public Health data base system. Eligible women were assigned to one of four community randomized intervention groups (IGs): (1) (IG1 N = 4197) personalised invitation letter, (2) (IG2 N = 3601) personalised invitation letter + informative leaflet, (3) (IG3 N = 6088) personalised invitation letter + informative leaflet + personalised phone call and (4) (Control N = 2079) based on spontaneous demand of cervical cancer screening as officially recommended. To evaluate screening coverage, we used heterogeneity tests to compare impact of the interventions and mixed logistic regression models to assess the age effect. We refer a "rescue" visit as the screening visit resulting from the study invitation. Among the 13,886 women in the IGs, 2,862 were evaluated as having an adequate screening history after the initial contact; 4,263 were lost to follow-up and 5,341 were identified as having insufficient screening and thus being eligible for a rescue visit. All intervention strategies significantly increased participation to screening compared to the control group. Coverage after the intervention reached 84.1% while the control group reached 64.8%. The final impact of our study was an increase of 20% in the three IGs and of 9% in the control group (p<0.001). Within the intervention arms, age was an important determinant of rescue visits showing a statistical interaction with the coverage attained in the IGs. Within the intervention groups, final screening coverage was significantly higher in IG3 (84.4%) (p<0.001). However, the differences were more substantial in the age groups 50-59 and those 60+. The highest impact of the IG3 intervention was observed among women 60+ y.o with 32.0% of them being rescued for screening. The lowest impact of the interventions was in younger women. The study confirms that using individual contact methods and assigning a fixed screening date notably increases participation in screening. The response to the invitation is strongly dependent on age. ClinicalTrials.gov NCT01373723.
Chen, Yong-jin; Chen, Ya-ning; Liu, Jia-zhen
2010-03-01
The variations vegetation coverage is the result of conjunct effects of inner and outer energy of the earth, however, the human activity always makes the coverage of vegetation change a lot. Based on the monitoring data of chemistry of groundwater and the coverage of vegetation from 2002 to 2007 in the lower reaches of Tarim River, relations between vegetation coverage and groundwater chemistry were studied. It is found that vegetation coverage at Sector A was more than 80%, and decreased from sector to sector, the coverage of Sector I was less than 10%. At the same sector, samples near to water source owned high coverage index, and samples far away from the river had low coverage index. The variations of pH in groundwater expressed similar regulation to vegetation coverage, that is, Sectors near the water source had higher pH index comparing than those far away. Regression between groundwater quality and vegetation coverage disclosed that the coverage of Populus euphratica climbed up along with increase of pH in groundwater, change of Tamarix ramosissima coverage expressed an opposite trend to the Populus euphratica with the same environmental factors. This phenomenon can interpret spatial distribution of Populus euphratica and Tamarix ramosissima in lower reaches of the Tarim River.
45 CFR 400.104 - Continued coverage of recipients who receive increased earnings from employment.
Code of Federal Regulations, 2010 CFR
2010-10-01
... Welfare OFFICE OF REFUGEE RESETTLEMENT, ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Refugee Medical Assistance Conditions of Eligibility for Refugee Medical Assistance § 400.104 Continued coverage of recipients who receive increased earnings from...
Urbanization reduces and homogenizes trait diversity in stream macroinvertebrate communities.
Barnum, Thomas R; Weller, Donald E; Williams, Meghan
2017-12-01
More than one-half of the world's population lives in urban areas, so quantifying the effects of urbanization on ecological communities is important for understanding whether anthropogenic stressors homogenize communities across environmental and climatic gradients. We examined the relationship of impervious surface coverage (a marker of urbanization) and the structure of stream macroinvertebrate communities across the state of Maryland and within each of Maryland's three ecoregions: Coastal Plain, Piedmont, and Appalachian, which differ in stream geomorphology and community composition. We considered three levels of trait organization: individual traits, unique combinations of traits, and community metrics (functional richness, functional evenness, and functional divergence) and three levels of impervious surface coverage (low [<2.5%], medium [2.5% to 10%], and high [>10%]). The prevalence of an individual trait differed very little between low impervious surface and high impervious surface sites. The arrangement of trait combinations in community trait space for each ecoregion differed when impervious surface coverage was low, but the arrangement became more similar among ecoregions as impervious surface coverage increased. Furthermore, trait combinations that occurred only at low or medium impervious surface coverage were clustered in a subset of the community trait space, indicating that impervious surface affected the presence of only a subset of trait combinations. Functional richness declined with increasing impervious surface, providing evidence for environmental filtering. Community metrics that include abundance were also sensitive to increasing impervious surface coverage: functional divergence decreased while functional evenness increased. These changes demonstrate that increasing impervious surface coverage homogenizes the trait diversity of macroinvertebrate communities in streams, despite differences in initial community composition and stream geomorphology among ecoregions. Community metrics were also more sensitive to changes in the abundance rather than the gain or loss of trait combinations, showing the potential for trait-based approaches to serve as early warning indicators of environmental stress for monitoring and biological assessment programs. © 2017 by the Ecological Society of America.
França, Giovanny V A; Restrepo-Méndez, María Clara; Maia, Maria Fátima S; Victora, Cesar G; Barros, Aluísio J D
2016-11-17
The Brazilian SUS (Unified Health System) was created in 1988 within the new constitution, based on the premises of being universal, comprehensive, and equitable. The SUS offers free health care, independent of contribution or affiliation. Since then, great efforts and increasing investments have been made for the system to achieve its goals. We assessed how coverage and equity in selected reproductive and maternal interventions progressed in Brazil from 1986 to 2013. We reanalysed data from four national health surveys carried out in Brazil in 1986, 1996, 2006 and 2013. We estimated coverage for six interventions [use of modern contraceptives; antenatal care (ANC) 1+ visits by any provider; ANC 4+ visits by any provider; first ANC visit during the first trimester of pregnancy; institutional delivery; and Caesarean sections] using standard international definitions, and stratified results by wealth quintile, urban or rural residence and country regions. We also calculated two inequality indicators: the slope index of inequality (SII) and the concentration index (CIX). All indicators showed steady increases in coverage over time. ANC 1+ and 4+ and institutional delivery reached coverage above 90 % in 2013. Prevalence of use of modern contraceptives was 83 % in 2013, indicating nearly universal satisfaction of need for contraception. On a less positive note, the proportion of C-sections has also grown continuously, reaching 55 % in 2013. There were marked reductions in wealth inequalities for all preventive interventions. Inequalities were significantly reduced for all indicators except for the C-section rate (p = 0.06), particularly in absolute terms (SII). Despite the difficulties faced in the implementation of SUS, coverage of essential interventions increased and equity has improved dramatically, due in most cases to marked increase in coverage among the poorest 40 %. An increase in unnecessary Caesarean sections was also observed during the period. Further evaluation on the quality of healthcare provided is needed.
NASA Astrophysics Data System (ADS)
A, Duo; Zhao, Wenji; Qu, Xinyuan; Jing, Ran; Xiong, Kai
2016-12-01
Global climate change has led to significant vegetation changes in the past half century. North China Plain, the most important grain production base of china, is undergoing a process of prominent warming and drying. The vegetation coverage, which is used to monitor vegetation change, can respond to climate change (temperature and precipitation). In this study, GIMMS (Global Inventory Modelling and Mapping Studies)-NDVI (Normalized Difference Vegetation Index) data, MODIS (Moderate-resolution Imaging Spectroradiometer) - NDVI data and climate data, during 1981-2013, were used to investigate the spatial distribution and changes of vegetation. The relationship between climate and vegetation on different spatial (agriculture, forest and grassland) and temporal (yearly, decadal and monthly) scales were also analyzed in North China Plain. (1) It was found that temperature exhibiting a slight increase trend (0.20 °C/10a, P < 0.01). This may be due to the disappearance of 0 °C isotherm, the rise of spring temperature. At the same time, precipitation showed a significant reduction trend (-1.75 mm/10a, P > 0.05). The climate mutation period was during 1991-1994. (2) Vegetation coverage slight increase was observed in the 55% of total study area, with a change rate of 0.00039/10a. Human activities may not only accelerate the changes of the vegetation coverage, but also c effect to the rate of these changes. (3) Overall, the correlation between the vegetation coverage and climatic factor is higher in monthly scale than yearly scale. The correlation analysis between vegetation coverage and climate changes showed that annual vegetation coverage was better correlatend with precipitation in grassland biome; but it showed a better correlated with temperature i the agriculture biome and forest biome. In addition, the vegetation coverage had sensitive time-effect respond to precipitation. (4) The vegetation coverage showed the same increasing trend before and after the climatic variations, but the rate of increase slowed down. From the vegetation coverage point of view, the grassland ecological zone had an obvious response to the climatic variations, but the agricultural ecological zones showed a significant response from the vegetation coverage change rate point of view. The effect of human activity in degradation region was higher than that in improvement area. But after the climate abruptly changing, the effect of human activity in improvement area was higher than that in degradation region, and the influence of human activity will continue in the future.
Opitz, Alexander K; Nenning, Andreas; Rameshan, Christoph; Kubicek, Markus; Götsch, Thomas; Blume, Raoul; Hävecker, Michael; Knop-Gericke, Axel; Rupprechter, Günther; Klötzer, Bernhard; Fleig, Jürgen
2017-10-18
Any substantial move of energy sources from fossil fuels to renewable resources requires large scale storage of excess energy, for example, via power to fuel processes. In this respect electrochemical reduction of CO 2 may become very important, since it offers a method of sustainable CO production, which is a crucial prerequisite for synthesis of sustainable fuels. Carbon dioxide reduction in solid oxide electrolysis cells (SOECs) is particularly promising owing to the high operating temperature, which leads to both improved thermodynamics and fast kinetics. Additionally, compared to purely chemical CO formation on oxide catalysts, SOECs have the outstanding advantage that the catalytically active oxygen vacancies are continuously formed at the counter electrode, and move to the working electrode where they reactivate the oxide surface without the need of a preceding chemical (e.g., by H 2 ) or thermal reduction step. In the present work, the surface chemistry of (La,Sr)FeO 3-δ and (La,Sr)CrO 3-δ based perovskite-type electrodes was studied during electrochemical CO 2 reduction by means of near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) at SOEC operating temperatures. These measurements revealed the formation of a carbonate intermediate, which develops on the oxide surface only upon cathodic polarization (i.e., under sufficiently reducing conditions). The amount of this adsorbate increases with increasing oxygen vacancy concentration of the electrode material, thus suggesting vacant oxygen lattice sites as the predominant adsorption sites for carbon dioxide. The correlation of carbonate coverage and cathodic polarization indicates that an electron transfer is required to form the carbonate and thus to activate CO 2 on the oxide surface. The results also suggest that acceptor doped oxides with high electron concentration and high oxygen vacancy concentration may be particularly suited for CO 2 reduction. In contrast to water splitting, the CO 2 electrolysis reaction was not significantly affected by metallic particles, which were exsolved from the perovskite electrodes upon cathodic polarization. Carbon formation on the electrode surface was only observed under very strong cathodic conditions, and the carbon could be easily removed by retracting the applied voltage without damaging the electrode, which is particularly promising from an application point of view.
2017-01-01
Any substantial move of energy sources from fossil fuels to renewable resources requires large scale storage of excess energy, for example, via power to fuel processes. In this respect electrochemical reduction of CO2 may become very important, since it offers a method of sustainable CO production, which is a crucial prerequisite for synthesis of sustainable fuels. Carbon dioxide reduction in solid oxide electrolysis cells (SOECs) is particularly promising owing to the high operating temperature, which leads to both improved thermodynamics and fast kinetics. Additionally, compared to purely chemical CO formation on oxide catalysts, SOECs have the outstanding advantage that the catalytically active oxygen vacancies are continuously formed at the counter electrode, and move to the working electrode where they reactivate the oxide surface without the need of a preceding chemical (e.g., by H2) or thermal reduction step. In the present work, the surface chemistry of (La,Sr)FeO3−δ and (La,Sr)CrO3−δ based perovskite-type electrodes was studied during electrochemical CO2 reduction by means of near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) at SOEC operating temperatures. These measurements revealed the formation of a carbonate intermediate, which develops on the oxide surface only upon cathodic polarization (i.e., under sufficiently reducing conditions). The amount of this adsorbate increases with increasing oxygen vacancy concentration of the electrode material, thus suggesting vacant oxygen lattice sites as the predominant adsorption sites for carbon dioxide. The correlation of carbonate coverage and cathodic polarization indicates that an electron transfer is required to form the carbonate and thus to activate CO2 on the oxide surface. The results also suggest that acceptor doped oxides with high electron concentration and high oxygen vacancy concentration may be particularly suited for CO2 reduction. In contrast to water splitting, the CO2 electrolysis reaction was not significantly affected by metallic particles, which were exsolved from the perovskite electrodes upon cathodic polarization. Carbon formation on the electrode surface was only observed under very strong cathodic conditions, and the carbon could be easily removed by retracting the applied voltage without damaging the electrode, which is particularly promising from an application point of view. PMID:28933825
Modelling the implications of moving towards universal coverage in Tanzania.
Borghi, Josephine; Mtei, Gemini; Ally, Mariam
2012-03-01
A model was developed to assess the impact of possible moves towards universal coverage in Tanzania over a 15-year time frame. Three scenarios were considered: maintaining the current situation ('the status quo'); expanded health insurance coverage (the estimated maximum achievable coverage in the absence of premium subsidies, coverage restricted to those who can pay); universal coverage to all (government revenues used to pay the premiums for the poor). The model estimated the costs of delivering public health services and all health services to the population as a proportion of Gross Domestic Product (GDP), and forecast revenue from user fees and insurance premiums. Under the status quo, financial protection is provided to 10% of the population through health insurance schemes, with the remaining population benefiting from subsidized user charges in public facilities. Seventy-six per cent of the population would benefit from financial protection through health insurance under the expanded coverage scenario, and 100% of the population would receive such protection through a mix of insurance cover and government funding under the universal coverage scenario. The expanded and universal coverage scenarios have a significant effect on utilization levels, especially for public outpatient care. Universal coverage would require an initial doubling in the proportion of GDP going to the public health system. Government health expenditure would increase to 18% of total government expenditure. The results are sensitive to the cost of health system strengthening, the level of real GDP growth, provider reimbursement rates and administrative costs. Promoting greater cross-subsidization between insurance schemes would provide sufficient resources to finance universal coverage. Alternately, greater tax funding for health could be generated through an increase in the rate of Value-Added Tax (VAT) or expanding the income tax base. The feasibility and sustainability of efforts to promote universal coverage will depend on the ability of the system to contain costs.
NASA Technical Reports Server (NTRS)
Flower, D. A.; Peckham, G. E.
1978-01-01
An instrument to measure atmospheric pressure at the earth's surface from an orbiting satellite would be a valuable addition to the expanding inventory of remote sensors. The subject of this report is such an instrument - the Microwave Pressure Sounder (MPS). It is shown that global-ocean coverage is attainable with sufficient accuracy, resolution and observational frequency for meteorological, oceanographic and climate research applications. Surface pressure can be deduced from a measurement of the absorption by an atmospheric column at a frequency in the wing of the oxygen band centered on 60 GHz. An active multifrequency instrument is needed to make this measurement with sufficient accuracy. The selection of optimum operating frequencies is based upon accepted models of surface reflection, oxygen, water vapor and cloud absorption. Numerical simulation using a range of real atmospheres defined by radiosonde observations were used to validate the frequency selection procedure. Analyses are presented of alternative system configurations that define the balance between accuracy and achievable resolution.
Exciton characteristics in graphene epoxide.
Zhu, Xi; Su, Haibin
2014-02-25
Exciton characteristics in graphene epoxide (GE) are investigated by density functional theory with quasi-particle corrections and many-body interactions. The nature of the exciton is influenced by epoxide content and detailed geometric configurations. Two kinds of excitons are identified in GE: Frenkel-like exciton originated from the sp(2) carbon cluster and charge-transfer exciton formed by localized states involving both oxygen and carbon atoms. The unusual blue shift associated with the Frenkel-like exciton leaking is highlighted. One scaling relationship is proposed to address the power-law dependence of Frenkel-like exciton binding strength on its size. The charge-transfer exciton appears in GE samples with the high oxygen coverage. Particularly, the exciton in GE structures exhibits long lifetime by analyzing both radiative and nonradiative decay processes. This study sheds light on the potential applications of GE-based structures with attractive high quantum yield in light emission and optoelectronic technology.
Kulik, Alexander; Desai, Nihar R; Shrank, William H; Antman, Elliott M; Glynn, Robert J; Levin, Raisa; Reisman, Lonny; Brennan, Troyen; Choudhry, Niteesh K
2013-09-10
Eliminating out-of-pocket costs for patients after myocardial infarction (MI) improves adherence to preventive therapies and reduces clinical events. Because adherence to medical therapy is low among patients treated with coronary artery bypass graft surgery (CABG), we evaluated the impact of providing full prescription coverage to this patient subgroup. The MI Free Rx Event and Economic Evaluation (FREEE) trial randomly assigned 5855 patients with MI to full prescription coverage or usual formulary coverage for all statins, β-blockers, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers. We assessed the impact of full prescription coverage on adherence, clinical outcomes, and healthcare costs using adjusted models among the 1052 patients who underwent CABG at the index hospitalization and 4803 who did not. CABG patients were older and had more comorbid illness (P<0.01). After MI, CABG patients were significantly more likely to receive β-blockers and statins but were less likely to receive angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy (P<0.01). Receiving full drug coverage increased rates of adherence to all preventative medications after CABG (all P<0.05). Full coverage was also associated with nonsignificant reductions in the rate of major vascular events or revascularization for patients treated with CABG (hazard ratio, 0.91; 95% confidence interval, 0.66-1.25) or without CABG (hazard ratio, 0.93; 95% confidence interval, 0.82-1.06), with no interaction noted (Pint=NS). After CABG, full prescription coverage significantly reduced patient out-of-pocket spending for drugs (P=0.001) without increasing overall health expenditures (P=NS). Eliminating drug copayments after MI provides consistent benefits to patients treated with or without CABG, leading to increased medication adherence, trends toward improved clinical outcomes, and reduced patient out-of-pocket expenses.
Kiely, Marilou; Boulianne, Nicole; Talbot, Denis; Ouakki, Manale; Guay, Maryse; Landry, Monique; Zafack, Joseline; Sauvageau, Chantal; De Serres, Gaston
2018-07-05
Between 2004 and 2016, in the province of Quebec (Canada), 4 new antigens were added in the early childhood vaccine schedule from birth to 18 months, increasing the number of injections or doses needed from 7 to 12. These additions may have decreased the proportion of children who had received all recommended vaccines. To assess the impact of the introduction of new vaccines to the childhood schedule on the 24-month vaccine coverage from 2006 to 2016 and identify factors associated with incomplete vaccination status by 24 months of age. We used the data from six cross-sectional vaccine coverage surveys conducted every two years which included a total of 3515 children aged 2 years old and randomly selected from the Quebec public health insurance database. Factors associated with an incomplete vaccine status by 24 months were identified with multivariable logistic regression. Despite the addition of 4 new vaccine antigens since 2004, the vaccine coverage remained high from 2006 (82.4%) through 2016 (88.3%) for vaccines present in the schedule since 2006. In 2016, vaccine coverage was 78.2% for all vaccines included in the schedule. The vaccine coverage of new vaccines increases rapidly within 2 years of their introduction. For both new and older vaccines, incomplete vaccine status by 24 months of age is associated with a delay of 30 days or more in receiving the vaccines scheduled at 2 and 12 months of age. Increasing to 12 the number of doses in the recommended schedule has slightly reduced the vaccine coverage by 24 months of age and the vaccine coverage of vaccines already in the schedule remained stable over the years. Future additions to the vaccine schedule may not be similarly accepted by the population and this will require continuing the monitoring of vaccine coverage. Copyright © 2018 Elsevier Ltd. All rights reserved.
Crude childhood vaccination coverage in West Africa: Trends and predictors of completeness.
Kazungu, Jacob S; Adetifa, Ifedayo M O
2017-02-15
Background : Africa has the lowest childhood vaccination coverage worldwide. If the full benefits of childhood vaccination programmes are to be enjoyed in sub-Saharan Africa, all countries need to improve on vaccine delivery to achieve and sustain high coverage. In this paper, we review trends in vaccination coverage, dropouts between vaccine doses and explored the country-specific predictors of complete vaccination in West Africa. Methods : We utilized datasets from the Demographic and Health Surveys Program, available for Benin, Burkina Faso, The Gambia, Ghana, Guinea, Cote d'Ivoire, Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone and Togo, to obtain coverage for Bacillus Calmette-Guerin, polio, measles, and diphtheria, pertussis and tetanus (DPT) vaccines in children aged 12 - 23 months. We also calculated the DPT1-to-DPT3 and DPT1-to-measles dropouts, and proportions of the fully immunised child (FIC). Factors predictive of FIC were explored using Chi-squared tests and multivariable logistic regression. Results : Overall, there was a trend of increasing vaccination coverage. The proportion of FIC varied significantly by country (range 24.1-81.4%, mean 49%). DPT1-to-DPT3 dropout was high (range 5.1% -33.9%, mean 16.3%). Similarly, DPT1-measles dropout exceeded 10% in all but four countries. Although no single risk factor was consistently associated with FIC across these countries, maternal education, delivery in a health facility, possessing a vaccine card and a recent post delivery visit to a health facility were the key predictors of complete vaccination. Conclusions : The low numbers of fully immunised children and high dropout between vaccine doses highlights weaknesses and the need to strengthen the healthcare and routine immunization delivery systems in this region. Country-specific correlates of complete vaccination should be explored further to identify interventions required to increase vaccination coverage. Despite the promise of an increasing trend in vaccination coverage in West African countries, more effort is required to attain and maintain global vaccination coverage targets.
Jung, Bock-Gie; Lee, Jin-A; Nam, Kyoung-Woo; Lee, Bong-Joo
2012-03-01
It has been suggested that drinking oxygenated water may improve oxygen availability, which may increase vitality and improving immune activity. The present study evaluated the immune enhancing effects of oxygenated drinking water in broiler chicks and demonstrated the protective efficacy of oxygenated drinking water against Salmonella Gallinarum in experimentally infected broiler chicks. Continuous drinking of oxygenated water markedly increased serum lysozyme activity, peripheral blood mononuclear cell proliferation and the CD4(+)/CD8(+) splenocyte ratio in broiler chicks. In the chicks experimentally infected with S. Gallinarum, oxygenated drinking water alleviated symptoms and increased survival. These findings suggest that oxygenated drinking water enhances immune activity in broiler chicks, and increases survivability against S. Gallinarum in experimentally infected broiler chicks.
Jung, Bock-Gie; Lee, Jin-A; Lee, Bong-Joo
2012-12-01
It has been considered that drinking oxygenated water improves oxygen availability, which may increase vitality and improve immune functions. The present study evaluated the effects of oxygenated drinking water on immune function in pigs. Continuous drinking of oxygenated water markedly increased peripheral blood mononuclear cell proliferation, interleukin-1β expression level and the CD4(+):CD8(+) cell ratio in pigs. During Salmonella Typhimurium infection, total leukocytes and relative cytokines expression levels were significantly increased in pigs consuming oxygenated water compared with pigs consuming tap water. These findings suggest that oxygenated drinking water enhances immune activity in pigs and increases immune responses of pigs during S. Typhimurium Infection.
Valeri, Fabio; Hatz, Christoph; Jordan, Dominique; Leuthold, Claudine; Czock, Astrid; Lang, Phung
2014-01-01
To assess vaccination coverage for adults living in Switzerland. Through a media campaign, the general population was invited during 1 month to bring their vaccination certificates to the pharmacies to have their immunisation status evaluated with the software viavac©, and to complete a questionnaire. A total of 496 pharmacies in Switzerland participated in the campaign, of which 284 (57%) submitted valid vaccination information. From a total of 3,634 participants in the campaign, there were 3,291 valid cases (participants born ≤ 1992) and 1,011 questionnaires completed. Vaccination coverage for the participants was 45.9% and 34.6% for five and six doses of diphtheria, 56.4% and 44.0% for tetanus and 66.3% and 48.0% for polio, respectively. Coverage estimates for one and two doses of measles vaccine were 76.5% and 49.4%, respectively, for the birth cohort 1967-1992 and 4.0% and 0.8%, respectively, for the cohort ≤ 1966. There was a significant difference in coverage for most vaccinations between the two aforementioned birth cohorts. A plot of the measles vaccine coverage over time shows that the increase in coverage correlated with policy changes in the Swiss Immunisation Schedule. Despite selection bias and low participation, this study indicates that vaccination coverage for the basic recommended immunisations in the adult population in Switzerland is suboptimal. More efforts using various means and methods are needed to increase immunisation coverage in adolescents before they leave school. An established method to determine vaccination coverage for the general population could provide invaluable insights into the effects of changes in vaccination policies and disease outbreaks.
Canestaro, W; Vodicka, E; Downing, D; Trussell, J
2017-01-01
Mandatory employer-based insurance coverage of contraception in the US has been a controversial component of the Affordable Care Act (ACA). Prior research has examined the cost-effectiveness of contraception in general; however, no studies have developed a formal decision model in the context of the new ACA provisions. As such, this study aims to estimate the relative cost-effectiveness of insurance coverage of contraception under employer-sponsored insurance coverage taking into consideration newer regulations allowing for religious exemptions. A decision model was developed from the employer perspective to simulate pregnancy costs and outcomes associated with insurance coverage. Method-specific estimates of contraception failure rates, outcomes and costs were derived from the literature. Uptake by marital status and age was drawn from a nationally representative database. Providing no contraception coverage resulted in 33 more unintended pregnancies per 1000 women (95% confidence range: 22.4; 44.0). This subsequently significantly increased the number of unintended births and terminations. Total costs were higher among uninsured women owing to higher costs of pregnancy outcomes. The effect of no insurance was greatest on unmarried women 20-29 years old. Denying female employees' full coverage of contraceptives increases total costs from the employer perspective, as well as the total number of terminations. Insurance coverage was found to be significantly associated with women's choice of contraceptive method in a large nationally representative sample. Using a decision model to extrapolate to pregnancy outcomes, we found a large and statistically significant difference in unintended pregnancy and terminations. Denying women contraception coverage may have significant consequences for pregnancy outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.
Correlation between measles vaccine doses: implications for the maintenance of elimination.
McKee, A; Ferrari, M J; Shea, K
2018-03-01
Measles eradication efforts have been successful at achieving elimination in many countries worldwide. Such countries actively work to maintain this elimination by continuing to improve coverage of two routine doses of measles vaccine following measles elimination. While improving measles vaccine coverage is always beneficial, we show, using a steady-state analysis of a dynamical model, that the correlation between populations receiving the first and second routine dose also has a significant impact on the population immunity achieved by a specified combination of first and second dose coverage. If the second dose is administered to people independently of whether they had the first dose, high second-dose coverage improves the proportion of the population receiving at least one dose, and will have a large effect on population immunity. If the second dose is administered only to people who have had the first dose, high second-dose coverage reduces the rate of primary vaccine failure, but does not reach people who missed the first dose; this will therefore have a relatively small effect on population immunity. When doses are administered dependently, and assuming the first dose has higher coverage, increasing the coverage of the first dose has a larger impact on population immunity than does increasing the coverage of the second. Correlation between vaccine doses has a significant impact on the level of population immunity maintained by current vaccination coverage, potentially outweighing the effects of age structure and, in some cases, recent improvements in vaccine coverage. It is therefore important to understand the correlation between vaccine doses as such correlation may have a large impact on the effectiveness of measles vaccination strategies.
The oxygen paradox of neurovascular coupling
Leithner, Christoph; Royl, Georg
2014-01-01
The coupling of cerebral blood flow (CBF) to neuronal activity is well preserved during evolution. Upon changes in the neuronal activity, an incompletely understood coupling mechanism regulates diameter changes of supplying blood vessels, which adjust CBF within seconds. The physiologic brain tissue oxygen content would sustain unimpeded brain function for only 1 second if continuous oxygen supply would suddenly stop. This suggests that the CBF response has evolved to balance oxygen supply and demand. Surprisingly, CBF increases surpass the accompanying increases of cerebral metabolic rate of oxygen (CMRO2). However, a disproportionate CBF increase may be required to increase the concentration gradient from capillary to tissue that drives oxygen delivery. However, the brain tissue oxygen content is not zero, and tissue pO2 decreases could serve to increase oxygen delivery without a CBF increase. Experimental evidence suggests that CMRO2 can increase with constant CBF within limits and decreases of baseline CBF were observed with constant CMRO2. This conflicting evidence may be viewed as an oxygen paradox of neurovascular coupling. As a possible solution for this paradox, we hypothesize that the CBF response has evolved to safeguard brain function in situations of moderate pathophysiological interference with oxygen supply. PMID:24149931
Hofer, Adam N; Abraham, Jean Marie; Moscovice, Ira
2011-01-01
Context: Provisions of the Patient Protection and Affordable Care Act of 2010 (PPACA) expand Medicaid to all individuals in families earning less than 133 percent of the federal poverty level (FPL) and make available subsidies to uninsured lower-income Americans (133 to 400 percent of FPL) without access to employer-based coverage to purchase insurance in new exchanges. Since primary care physicians typically serve as the point of entry into the health care delivery system, an adequate supply of them is critical to meeting the anticipated increase in demand for medical care resulting from the expansion of coverage. This article provides state-level estimates of the anticipated increases in primary care utilization given the PPACA's provisions for expanded coverage. Methods: Using the Medical Expenditure Panel Survey, this article estimates a multivariate regression model of annual primary care utilization. Using the model estimates and state-level information regarding the number of uninsured, it predicts, by state, the change in primary care visits expected from the expanded coverage. Finally, the article predicts the number of primary care physicians needed to accommodate this change in utilization. Findings: This expanded coverage is predicted to increase by 2019 the number of annual primary care visits between 15.07 million and 24.26 million. Assuming stable levels of physicians’ productivity, between 4,307 and 6,940 additional primary care physicians would be needed to accommodate this increase. Conclusions: The PPACA's health insurance expansion parameters are expected to significantly increase the use of primary care. Two strategies that policymakers may consider are creating stronger financial incentives to attract medical school students to primary care and changing the delivery of care in ways that lead to operational improvements, higher throughput, and better quality of care. PMID:21418313
van Hoek, Albert Jan; Melegaro, Alessia; Zagheni, Emelio; Edmunds, W John; Gay, Nigel
2011-03-16
This study updates previous work on modelling the incidence of varicella and Herpes Zoster (HZ) following the introduction of childhood vaccination. The updated model includes new data on age-specific contact patterns, as well as data on the efficacy of zoster vaccination in the elderly and allows for HZ among vaccinees. The current study also looks at two-dose varicella childhood programmes, and assesses the combined impact of varicella vaccination in childhood and zoster vaccination of the elderly. The results suggest that a two-dose schedule is likely to reduce the incidence of varicella to very low levels, provided first dose coverage is around 90% and second dose coverage is in excess of 70%. Single dose varicella vaccination programmes are expected to result in large numbers of breakthrough cases. Childhood vaccination is expected to increase the incidence of zoster for more than 40 years after introduction of the programme, the magnitude of this increase being influenced primarily by the duration of boosting following exposure to the varicella zoster virus. Though this increase in zoster incidence can be partly offset by vaccination of the elderly, the effectiveness of this combined strategy is limited, as much of the increase occurs in those adults too young to be vaccinated. Childhood vaccination at intermediate levels of coverage (70% and 60% for first and second dose coverage respectively) is expected to lead to an increase in adult varicella. At high coverage (90% and 80% coverage) this is unlikely to be the case. These results will be used to inform a cost-effectiveness analysis of combined varicella and zoster vaccination programmes. Copyright © 2011 Elsevier Ltd. All rights reserved.
Jarlenski, Marian; Baller, Julia; Borrero, Sonya; Bennett, Wendy L
2016-03-01
To examine time trends in disparities in low-income children's health insurance coverage and access to care by family immigration status. We used data from the National Survey of Children's Health in 2003 to 2011-2012, including 83,612 children aged 0 to 17 years with family incomes <200% of the federal poverty level. We examined 3 immigration status categories: citizen children with nonimmigrant parents; citizen children with immigrant parents; and immigrant children. We used multivariable regression analyses to obtain adjusted trends in health insurance coverage and access to care. All low-income children experienced gains in health insurance coverage and access to care from 2003 to 2011-2012, regardless of family immigration status. Relative to citizen children with nonimmigrant parents, citizen children with immigrant parents had a 5 percentage point greater increase in health insurance coverage (P = .06), a 9 percentage point greater increase in having a personal doctor or nurse (P < .01), and an 11 percentage point greater increase in having no unmet medical need (P < .01). Immigrant children had significantly lower health insurance coverage than other groups. However, the group had a 14 percentage point greater increase in having a personal doctor or nurse (P < .01) and a 26 percentage point greater increase in having no unmet medical need (P < .01) relative to citizen children with nonimmigrant parents. Some disparities in access to care related to family immigration status have lessened over time among children in low-income families, although large disparities still exist. Policy efforts are needed to ensure that children of immigrant parents and immigrant children are able to access health insurance and health care. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.
Braeckman, Tessa; Lernout, Tinne; Top, Geert; Paeps, Annick; Roelants, Mathieu; Hoppenbrouwers, Karel; Van Damme, Pierre; Theeten, Heidi
2014-01-09
Infant immunisation coverage in Flanders, Belgium, is monitored through repeated coverage surveys. With the increased use of Vaccinnet, the web-based ordering system for vaccines in Flanders set up in 2004 and linked to an immunisation register, this database could become an alternative to quickly estimate vaccination coverage. To evaluate its current accuracy, coverage estimates generated from Vaccinnet alone were compared with estimates from the most recent survey (2012) that combined interview data with data from Vaccinnet and medical files. Coverage rates from registrations in Vaccinnet were systematically lower than the corresponding estimates obtained through the survey (mean difference 7.7%). This difference increased by dose number for vaccines that require multiple doses. Differences in administration date between the two sources were observed for 3.8-8.2% of registered doses. Underparticipation in Vaccinnet thus significantly impacts on the register-based immunisation coverage estimates, amplified by underregistration of administered doses among vaccinators using Vaccinnet. Therefore, survey studies, despite being labour-intensive and expensive, currently provide more complete and reliable results than register-based estimates alone in Flanders. However, further improvement of Vaccinnet's completeness will likely allow more accurate estimates in the nearby future. Copyright © 2013 Elsevier Ltd. All rights reserved.
Evaluation of a vaccine passport to improve vaccine coverage in people living with HIV.
Chadwick, D R; Corbett, K; Mann, S; Teruzzi, B; Horner, S
2018-01-01
An increased risk of vaccine-preventable infections (VPIs) is seen in people living with HIV (PLWH), and current vaccine coverage and immunity is variable. Vaccine passports have the potential to improve vaccine coverage. The objective was to assess how successful a vaccine passport was in improving vaccine coverage in PLWH. Baseline immunity to VPIs was established in PLWH attending a single HIV clinic and vaccinations required were determined based on the BHIVA Vaccination Guidelines (2015). The passport was completed and the PLWH informed about additional vaccines they should obtain from primary care. After 6-9 months the passport was reviewed including confirmation if vaccines were given. PLWH satisfaction with the system was evaluated by a survey. Seventy-three PLWH provided sufficient data for analysis. At baseline significant proportions of PLWH were not immune/unvaccinated to the main VPIs, especially human papillomavirus, pneumococcus and measles. After the passport was applied immunity improved significantly (56% overall, p < 0.01) for most VPIs; however, full coverage was not achieved. The system was popular with PLWH. The passport was successful in increasing vaccination coverage although full or near-full coverage was not achieved. A more successful service would probably be achieved by commissioning English HIV clinics to provide all vaccines.
Seasonal influenza vaccine coverage among high-risk populations in Thailand, 2010-2012.
Owusu, Jocelynn T; Prapasiri, Prabda; Ditsungnoen, Darunee; Leetongin, Grit; Yoocharoen, Pornsak; Rattanayot, Jarowee; Olsen, Sonja J; Muangchana, Charung
2015-01-29
The Advisory Committee on Immunization Practice of Thailand prioritizes seasonal influenza vaccinations for populations who are at highest risk for serious complications (pregnant women, children 6 months-2 years, persons ≥65 years, persons with chronic diseases, obese persons), and healthcare personnel and poultry cullers. The Thailand government purchases seasonal influenza vaccine for these groups. We assessed vaccination coverage among high-risk groups in Thailand from 2010 to 2012. National records on persons who received publicly purchased vaccines from 2010 to 2012 were analyzed by high-risk category. Denominator data from multiple sources were compared to calculate coverage. Vaccine coverage was defined as the proportion of individuals in each category who received the vaccine. Vaccine wastage was defined as the proportion of publicly purchased vaccines that were not used. From 2010 to 2012, 8.18 million influenza vaccines were publicly purchased (range, 2.37-3.29 million doses/year), and vaccine purchases increased 39% over these years. Vaccine wastage was 9.5%. Approximately 5.7 million (77%) vaccine doses were administered to persons ≥65 years and persons with chronic diseases, 1.4 million (19%) to healthcare personnel/poultry cullers, 82,570 (1.1%) to children 6 months-2 years, 78,885 (1.1%) to obese persons, 26,481 (0.4%) to mentally disabled persons, and 17,787 (0.2%) to pregnant women. Between 2010 and 2012, coverage increased among persons with chronic diseases (8.6% versus 14%; p<0.01) and persons ≥65 years (12%, versus 20%; p<0.01); however, coverage decreased for mentally disabled persons (6.1% versus 4.9%; p<0.01), children 6 months-2 years (2.3% versus 0.9%; p<0.01), pregnant women (1.1% versus 0.9%; p<0.01), and obese persons (0.2% versus 0.1%; p<0.01). From 2010 to 2012, the availability of publicly purchased vaccines increased. While coverage remained low for all target groups, coverage was highest among persons ≥65 years and persons with chronic diseases. Annual coverage assessments are necessary to promote higher coverage among high-risk groups in Thailand. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Seasonal influenza vaccine coverage among high-risk populations in Thailand, 2010–2012
Owusu, Jocelynn T.; Prapasiri, Prabda; Ditsungnoen, Darunee; Leetongin, Grit; Yoocharoen, Pornsak; Rattanayot, Jarowee; Olsen, Sonja J.; Muangchana, Charung
2015-01-01
Background The Advisory Committee on Immunization Practice of Thailand prioritizes seasonal influenza vaccinations for populations who are at highest risk for serious complications (pregnant women, children 6 months–2 years, persons ≥65 years, persons with chronic diseases, obese persons), and health-care personnel and poultry cullers. The Thailand government purchases seasonal influenza vaccine for these groups. We assessed vaccination coverage among high-risk groups in Thailand from 2010 to 2012. Methods National records on persons who received publicly purchased vaccines from 2010 to 2012 were analyzed by high-risk category. Denominator data from multiple sources were compared to calculate coverage. Vaccine coverage was defined as the proportion of individuals in each category who received the vaccine. Vaccine wastage was defined as the proportion of publicly purchased vaccines that were not used. Results From 2010 to 2012, 8.18 million influenza vaccines were publicly purchased (range, 2.37–3.29 million doses/year), and vaccine purchases increased 39% over these years. Vaccine wastage was 9.5%. Approximately 5.7 million (77%) vaccine doses were administered to persons ≥65 years and persons with chronic diseases, 1.4 million (19%) to healthcare personnel/poultry cullers, 82,570 (1.1%) to children 6 months–2 years, 78,885 (1.1%) to obese persons, 26,481 (0.4%) to mentally disabled persons, and 17,787 (0.2%) to pregnant women. Between 2010 and 2012, coverage increased among persons with chronic diseases (8.6% versus 14%; p < 0.01) and persons ≥65 years (12%, versus 20%; p < 0.01); however, coverage decreased for mentally disabled persons (6.1% versus 4.9%; p < 0.01), children 6 months–2 years (2.3% versus 0.9%; p < 0.01), pregnant women (1.1% versus 0.9%; p < 0.01), and obese persons (0.2% versus 0.1%; p < 0.01). Conclusions From 2010 to 2012, the availability of publicly purchased vaccines increased. While coverage remained low for all target groups, coverage was highest among persons ≥65 years and persons with chronic diseases. Annual coverage assessments are necessary to promote higher coverage among high-risk groups in Thailand. PMID:25454853
Low abundance of the matrix arm of complex I in mitochondria predicts longevity in mice
Miwa, Satomi; Jow, Howsun; Baty, Karen; Johnson, Amy; Czapiewski, Rafal; Saretzki, Gabriele; Treumann, Achim; von Zglinicki, Thomas
2014-01-01
Mitochondrial function is an important determinant of the ageing process; however, the mitochondrial properties that enable longevity are not well understood. Here we show that optimal assembly of mitochondrial complex I predicts longevity in mice. Using an unbiased high-coverage high-confidence approach, we demonstrate that electron transport chain proteins, especially the matrix arm subunits of complex I, are decreased in young long-living mice, which is associated with improved complex I assembly, higher complex I-linked state 3 oxygen consumption rates and decreased superoxide production, whereas the opposite is seen in old mice. Disruption of complex I assembly reduces oxidative metabolism with concomitant increase in mitochondrial superoxide production. This is rescued by knockdown of the mitochondrial chaperone, prohibitin. Disrupted complex I assembly causes premature senescence in primary cells. We propose that lower abundance of free catalytic complex I components supports complex I assembly, efficacy of substrate utilization and minimal ROS production, enabling enhanced longevity. PMID:24815183
Empirical algorithms to predict aragonite saturation state
NASA Astrophysics Data System (ADS)
Turk, Daniela; Dowd, Michael
2017-04-01
Novel sensor packages deployed on autonomous platforms (Profiling Floats, Gliders, Moorings, SeaCycler) and biogeochemical models have a potential to increase the coverage of a key water chemistry variable, aragonite saturation state (ΩAr) in time and space, in particular in the under sampled regions of global ocean. However, these do not provide the set of inorganic carbon measurements commonly used to derive ΩAr. There is therefore a need to develop regional predictive models to determine ΩAr from measurements of commonly observed or/and non carbonate oceanic variables. Here, we investigate predictive skill of several commonly observed oceanographic variables (temperature, salinity, oxygen, nitrate, phosphate and silicate) in determining ΩAr using climatology and shipboard data. This will allow us to assess potential for autonomous sensors and biogeochemical models to monitor ΩAr regionally and globally. We apply the regression models to several time series data sets and discuss regional differences and their implications for global estimates of ΩAr.
Scott, Susana; Odutola, Aderonke; Mackenzie, Grant; Fulford, Tony; Afolabi, Muhammed O; Lowe Jallow, Yamundow; Jasseh, Momodou; Jeffries, David; Dondeh, Bai Lamin; Howie, Stephen R C; D'Alessandro, Umberto
2014-01-01
To evaluate the coverage and timeliness of the Expanded Programme on Immunisation (EPI) in The Gambia. Vaccination data were obtained between January 2005 and December 2012 from the Farafenni Health and Demographic Surveillance System (FHDSS), the Basse Health and Demographic Surveillance System (BHDSS), the Kiang West Demographic surveillance system (KWDSS), a cluster survey in the more urban Western Health Region (WR) and a cross sectional study in four clinics in the semi-urban Greater Banjul area of WR. Kaplan-Meier survival function was used to estimate the proportion vaccinated by age and to assess timeliness to vaccination. BCG vaccine uptake was over 95% in all regions. Coverage of DPT1 ranged from 93.2% in BHDSS to 99.8% in the WR. Coverage decreased with increasing number of DPT doses; DPT3 coverage ranged from 81.7% in BHDSS to 99.0% in WR. Measles vaccination coverage ranged from 83.3% in BHDSS to 97.0% in WR. DPT4 booster coverage was low and ranged from 43.9% in the WR to 82.8% in KWDSS. Across all regions, delaying on previous vaccinations increased the likelihood of being delayed for the subsequent vaccination. The Gambia health system achieves high vaccine coverage in the first year of life. However, there continues to be a delay to vaccination which may impact on the introduction of new vaccines. Examples of effectively functioning EPI programmes such as The Gambia one may well be important models for other low income countries struggling to achieve high routine vaccination coverage.
Mereckiene, J; Cotter, S; Nicoll, A; Lopalco, P; Noori, T; Weber, Jt; D'Ancona, F; Levy-Bruhl, D; Dematte, L; Giambi, C; Valentiner-Branth, P; Stankiewicz, I; Appelgren, E; O Flanagan, D
2014-04-24
Since 2008, annual surveys of influenza vaccination policies, practices and coverage have been undertaken in 29 European Union (EU)/ European Economic Area (EEA) countries. After 2009, this monitored the impact of European Council recommendation to increase vaccination coverage to 75% among risk groups. This paper summarises the results of three seasonal influenza seasons: 2008/09, 2009/10 and 2010/11. In 2008/09, 27/29 countries completed the survey; in 2009/10 and 2010/11, 28/29 completed it. All or almost all countries recommended vaccination of older people (defined as those aged ≥50, ≥55, ≥59, ≥60 or ≥65 years), and people aged ≥6 months with clinical risk and healthcare workers. A total of 23 countries provided vaccination coverage data for older people, but only 7 and 10 had data for the clinical risk groups and healthcare workers, respectively. The number of countries recommending vaccination for some or all pregnant women increased from 10 in 2008/09 to 22 in 2010/11. Only three countries could report coverage among pregnant women. Seasonal influenza vaccination coverage during and after the pandemic season in older people and clinical groups remained unchanged in countries with higher coverage. However, small decreases were seen in most countries during this period. The results of the surveys indicate that most EU/EEA countries recommend influenza vaccination for the main target groups; however, only a few countries have achieved the target of 75% coverage among risk groups. Coverage among healthcare workers remained low.
Lipton, Brandy J; Decker, Sandra L
2016-02-01
Medicaid is the main public health insurance program for individuals with low income in the United States. Some state Medicaid programs cover preventive eye care services and vision correction, while others cover emergency eye care only. Similar to other optional benefits, states may add and drop adult vision benefits over time. This article examines whether providing adult vision benefits is associated with an increase in the percentage of low-income individuals with appropriately corrected distance vision as measured during an eye exam. We estimate the effect of Medicaid vision coverage on the likelihood of having appropriately corrected distance vision using examination data from the 2001-2008 National Health and Nutrition Examination Survey. We compare vision outcomes for Medicaid beneficiaries (n = 712) and other low income adults not enrolled in Medicaid (n = 4786) before and after changes to state vision coverage policies. Between 29 and 33 states provided Medicaid adult vision benefits during 2001-2008, depending on the year. Our findings imply that Medicaid adult vision coverage is associated with a significant increase in the percentage of Medicaid beneficiaries with appropriately corrected distance vision of up to 10 percentage points. Providing vision coverage to adults on Medicaid significantly increases the likelihood of appropriate correction of distance vision. Further research on the impact of vision coverage on related functional outcomes and the effects of Medicaid coverage of other services may be appropriate. Copyright © 2015 Elsevier Ltd. All rights reserved.
Dual path mechanism in the thermal reduction of graphene oxide.
Larciprete, Rosanna; Fabris, Stefano; Sun, Tao; Lacovig, Paolo; Baraldi, Alessandro; Lizzit, Silvano
2011-11-02
Graphene is easily produced by thermally reducing graphene oxide. However, defect formation in the C network during deoxygenation compromises the charge carrier mobility in the reduced material. Understanding the mechanisms of the thermal reactions is essential for defining alternative routes able to limit the density of defects generated by carbon evolution. Here, we identify a dual path mechanism in the thermal reduction of graphene oxide driven by the oxygen coverage: at low surface density, the O atoms adsorbed as epoxy groups evolve as O(2) leaving the C network unmodified. At higher coverage, the formation of other O-containing species opens competing reaction channels, which consume the C backbone. We combined spectroscopic tools and ab initio calculations to probe the species residing on the surface and those released in the gas phase during heating and to identify reaction pathways and rate-limiting steps. Our results illuminate the current puzzling scenario of the low temperature gasification of graphene oxide.
Brigham, Mark E.; Payne, Gregory A.; Andrews, William J.; Abbott, Marvin M.
2002-01-01
The sampling network was evaluated with respect to areal coverage, sampling frequency, and analytical schedules. Areal coverage could be expanded to include one additional watershed that is not part of the current network. A new sampling site on the North Canadian River might be useful because of expanding urbanization west of the city, but sampling at some other sites could be discontinued or reduced based on comparisons of data between the sites. Additional real-time or periodic monitoring for dissolved oxygen may be useful to prevent anoxic conditions in pools behind new low-water dams. The sampling schedules, both monthly and quarterly, are adequate to evaluate trends, but additional sampling during flow extremes may be needed to quantify loads and evaluate water-quality during flow extremes. Emerging water-quality issues may require sampling for volatile organic compounds, sulfide, total phosphorus, chlorophyll-a, Esherichia coli, and enterococci, as well as use of more sensitive laboratory analytical methods for determination of cadmium, mercury, lead, and silver.
Surface-interface exploration of Mg deposited on Si(100) and oxidation effect on interfacial layer
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sarpi, B.; Daineche, R.; Girardeaux, C.
Using scanning tunneling microscopy and spectroscopy, Auger electron spectroscopy, and low energy electron diffraction, we have studied the growth of Mg deposited on Si(100)-(2 × 1). Coverage from 0.05 monolayer (ML) to 3 ML was investigated at room temperature. The growth mode of the magnesium is a two steps process. At very low coverage, there is formation of an amorphous ultrathin silicide layer with a band gap of 0.74 eV, followed by a layer-by-layer growth of Mg on top of this silicide layer. Topographic images reveal that each metallic Mg layer is formed by 2D islands coalescence process on top of the silicidemore » interfacial layer. During oxidation of the Mg monolayer, the interfacial silicide layer acts as diffusion barrier for the oxygen atoms with a decomposition of the silicide film to a magnesium oxide as function of O{sub 2} exposure.« less
Bailey, Steffani R.; Cowburn, Stuart; Marino, Miguel; Angier, Heather; DeVoe, Jennifer E.
2016-01-01
Objectives. To assess longitudinal patterns of community health center (CHC) utilization and the effect of insurance discontinuity after Oregon’s 2008 Medicaid expansion (the Oregon Experiment). Methods. We conducted a retrospective cohort study with electronic health records and Medicaid data. We divided individuals who gained Medicaid in the Oregon Experiment into those who maintained (n = 788) or lost (n = 944) insurance coverage. We compared these groups with continuously insured (n = 921) and continuously uninsured (n = 5416) reference groups for community health center utilization rates over a 36-month period. Results. Both newly insured groups increased utilization in the first 6 months. After 6 months, use among those who maintained coverage stabilized at a level consistent with the continuously insured, whereas it returned to baseline for those who lost coverage. Conclusions. Individuals who maintained coverage through Oregon’s Medicaid expansion increased long-term utilization of CHCs, whereas those with unstable coverage did not. Policy implications. This study predicts long-term increase in CHC utilization following Affordable Care Act Medicaid expansion and emphasizes the need for policies that support insurance retention. PMID:26890164
Superstructures at Te/Au(111) interface evolving upon increasing Te coverage
NASA Astrophysics Data System (ADS)
Guan, Jiaqi; Huang, Xiaochun; Xu, Xiaofeng; Zhang, Shuyuan; Jia, Xun; Zhu, Xuetao; Wang, Weihua; Guo, Jiandong
2018-03-01
By in-situ low temperature scanning tunneling microscopy, we systematically investigated the superstructure evolution at Te/Au(111) interface upon increasing Te coverage. Te atoms form one-dimensional √{ 3} R30∘ chains at ∼0.10 monolayer (ML) coverage. Two two-dimensional chiral superstructures, (√{ 111} ×√{ 111}) R 4 .7∘ and (3√{ 21} × 3√{ 21}) R 10 .9∘ , are selectively formed with the Te coverage below and above 1/3 ML, respectively. The two chiral superstructures can be converted to each other reversibly by adding Te atoms or moderately annealing. A honeycomb-like superstructure, decorated with adatoms that are distributed in quasi-one-dimensional chains, is observed by further increasing the Te coverage to 4/9 ML. At the Te/Au(111) interface, an interfacial state at -0.65 eV to -0.55 eV below the Fermi level is also resolved by scanning tunneling spectroscopy. The formation of these Te-induced high-order superstructures is accompanied by relaxation of gold atoms in the surface layer, indicating a strong Te-Au interaction. Our work demonstrates a reliable method to fabricate Te nanostructures on noble metals in a controlled way.
Rittenhouse, Diane R; Braveman, Paula; Marchi, Kristen
2003-06-01
To examine trends in prenatal insurance coverage and utilization of care in California over two decades in the context of expansions in Medi-Cal (California's Medicaid) and other public efforts to increase prenatal care utilization. Retrospective univariate and bivariate analysis of prenatal care coverage and utilization data from 10,192,165 California birth certificates, 1980-99; descriptive analysis of California poverty and unemployment data from the U.S. Census Bureau Current Population Survey; review of public health and social policy literature. The proportion of mothers with Medi-Cal coverage for prenatal care increased from 28.2 to 47.5% between 1989 and 1994, and the proportion uninsured throughout pregnancy decreased from 13.2 to 3.2%. Since the mid-1990s, fewer than 3% of women have had no insurance coverage for prenatal care. Between 1989 and 1999, the proportion of women with first trimester initiation of prenatal care increased from 72.6 to 83.6%, reversing the previous decade's trend, and the proportion of women with adequate numbers of visits rose from 70.7 to 83.1%. Improvements in utilization measures were greater among disadvantaged social groups. Improvements in California during the 1990s coincided with a multifaceted public health effort to increase both prenatal care coverage and utilization, and do not appear to be explained by changes in the economy, maternal characteristics, the overall organization/delivery of health care, or other social policies. While this ecologic study cannot produce definitive conclusions regarding causality, these results suggest an important victory for public health in California.
Topoclimatological and snowhydrological survey of Switzerland
NASA Technical Reports Server (NTRS)
Winiger, M. (Principal Investigator)
1980-01-01
The author has identified the following significant results. Low temperature zones depend on the topography and the terrain coverage type (besides the meteorological situation). The usual pattern of cold zones at the bottom of the valleys, warmer belts along the valley slopes, and cold mountain tops is modified by the terrain coverage type. Rural and forested areas normally have different surface temperatures, but along a vertical profile the temperature decrease (or increase) is often of the same order of magnitude. Because there is also a close correlation between the topography and terrain coverage (high percentage of forested areas at the valley slopes up to the timber line, much less along the valley floors), the surface temperature of the warm slope zone is increased compared to a valley profile with uniform coverage.
Friction force microscopy at a regularly stepped Au(665) electrode: Anisotropy effects
NASA Astrophysics Data System (ADS)
Podgaynyy, Nikolay; Iqbal, Shahid; Baltruschat, Helmut
2015-01-01
Using friction force microscopy, friction was determined for the AFM-tip scanning parallel and vertically to the monoatomic steps of Au(665) electrode for different coverages of Cu in sulfuric acid. When the tip was scanning parallel to the steps, the results were similar to those obtained before for a Au(111) surface: a higher coverage of Cu leads to an increased friction. However, differently from Au(111), no transitions in the friction coefficient were observed with increasing load. Atomic stick slip was observed both for the Au surface and the √{ 3} × √{ 3} honeycomb Cu adlayer with a Cu coverage of 2/3. When the tip was scanning perpendicular to the steps, friction did not depend much on coverage; astonishingly, atomic stick slip was also observed.
Castro, Carlos Henrique Viana de; Cruvinel, Marcos Guilherme Cunha; Carneiro, Fabiano Soares; Silva, Yerkes Pereira; Cabral, Antônio Carlos Vieira; Bessa, Roberto Cardoso
2009-01-01
Despite changes in pulmonary function, maternal oxygenation is maintained during obstetric regional blocks. But in those situations, the administration of supplementary oxygen to parturients is a common practice. Good fetal oxygenation is the main justification; however, this has not been proven. The objective of this randomized, prospective study was to test the hypothesis of whether maternal hyperoxia is correlated with an increase in fetal gasometric parameters in elective cesarean sections. Arterial blood gases of 20 parturients undergoing spinal block with different inspired fractions of oxygen were evaluated and correlated with fetal arterial blood gases. An increase in maternal inspired fraction of oxygen did not show any correlation with an increase of fetal partial oxygen pressure. Induction of maternal hyperoxia by the administration of supplementary oxygen did not increase fetal partial oxygen pressure. Fetal gasometric parameters did not change even when maternal parameters changed, induced by hyperoxia, during cesarean section under spinal block.
Differences in private health insurance coverage for working male Hispanics.
Fronstin, P; Goldberg, L G; Robins, P K
1997-01-01
In 1993, 33.8% of all nonelderly adult Hispanics living in the United States lacked health insurance coverage (either private or public), compared to 8.1% of the entire nonelderly population. Because Hispanics are more likely to be uninsured than any other ethnic group and because they are the fastest growing minority group in the United States, the increase in the Hispanic population is likely to increase the proportion of the population without health insurance. Particularly striking are differences in private health insurance coverage among the three major Hispanic groups--Cuban-Americans, Mexican-Americans, and Puerto Ricans. In this paper, regression-based decomposition analysis is used to explain the sources of differences in private health insurance coverage among working males in these three group. The results indicate that among the study population, Cuban-Americans have higher rates of private health insurance coverage than Mexican-Americans and Puerto Ricans, and that wage rates, levels of education, age, occupation, and marital status explain most of the difference.
NASA Technical Reports Server (NTRS)
Waligora, J. M.; Horrigan, D. J., Jr.; Conkin, J.; Dierlam, J. J.; Stanford, J., Jr.; Riddle, J. R.
1984-01-01
Male and female subjects prebreathed air or 100% oxygen through a mask for 3.0 hours while comfortably reclined. Blood pressures, heart rate, and cardiac output were collected before and after the prebreathe. Peripheral vascular resistance (PVR) was calculated from these parameters and increased by 29% during oxygen prebreathing and 15% during air prebreathing. The oxygen contributed substantially to the increase in PVR. Diastolic blood pressure increased by 18% during the oxygen prebreathe while stystolic blood pressure showed no change under either procedure. The increase in PVR during air prebreathing was attributed to procedural stress common to air and oxygen prebreathing.
Overcoming Spatial and Temporal Barriers to Public Access Defibrillators Via Optimization
Sun, Christopher L. F.; Demirtas, Derya; Brooks, Steven C.; Morrison, Laurie J.; Chan, Timothy C.Y.
2016-01-01
BACKGROUND Immediate access to an automated external defibrillator (AED) increases the chance of survival from out-of-hospital cardiac arrest (OHCA). Current deployment usually considers spatial AED access, assuming AEDs are available 24 h a day. OBJECTIVES We sought to develop an optimization model for AED deployment, accounting for spatial and temporal accessibility, to evaluate if OHCA coverage would improve compared to deployment based on spatial accessibility alone. METHODS This was a retrospective population-based cohort study using data from the Toronto Regional RescuNET cardiac arrest database. We identified all nontraumatic public-location OHCAs in Toronto, Canada (January 2006 through August 2014) and obtained a list of registered AEDs (March 2015) from Toronto emergency medical services. We quantified coverage loss due to limited temporal access by comparing the number of OHCAs that occurred within 100 meters of a registered AED (assumed 24/7 coverage) with the number that occurred both within 100 meters of a registered AED and when the AED was available (actual coverage). We then developed a spatiotemporal optimization model that determined AED locations to maximize OHCA actual coverage and overcome the reported coverage loss. We computed the coverage gain between the spatiotemporal model and a spatial-only model using 10-fold cross-validation. RESULTS We identified 2,440 atraumatic public OHCAs and 737 registered AED locations. A total of 451 OHCAs were covered by registered AEDs under assumed 24/7 coverage, and 354 OHCAs under actual coverage, representing a coverage loss of 21.5% (p < 0.001). Using the spatiotemporal model to optimize AED deployment, a 25.3% relative increase in actual coverage was achieved over the spatial-only approach (p < 0.001). CONCLUSIONS One in 5 OHCAs occurred near an inaccessible AED at the time of the OHCA. Potential AED use was significantly improved with a spatiotemporal optimization model guiding deployment. PMID:27539176
Analyzing the test process using structural coverage
NASA Technical Reports Server (NTRS)
Ramsey, James; Basili, Victor R.
1985-01-01
A large, commercially developed FORTRAN program was modified to produce structural coverage metrics. The modified program was executed on a set of functionally generated acceptance tests and a large sample of operational usage cases. The resulting structural coverage metrics are combined with fault and error data to evaluate structural coverage. It was shown that in the software environment the functionally generated tests seem to be a good approximation of operational use. The relative proportions of the exercised statement subclasses change as the structural coverage of the program increases. A method was also proposed for evaluating if two sets of input data exercise a program in a similar manner. Evidence was provided that implies that in this environment, faults revealed in a procedure are independent of the number of times the procedure is executed and that it may be reasonable to use procedure coverage in software models that use statement coverage. Finally, the evidence suggests that it may be possible to use structural coverage to aid in the management of the acceptance test processed.
Brundin, T; Wahren, J
1994-05-01
Splanchnic and whole-body oxygen uptake, blood flow, and blood temperature were studied in 10 healthy subjects before and during 2 hours after oral ingestion of 900 kJ of fish protein. Indirect calorimetry and catheter techniques were used, including blood thermometry in arterial, pulmonary arterial, and hepatic venous blood. After the meal, pulmonary oxygen uptake increased from a basal value of 272 +/- 11 to 332 +/- 23 mL/min. During the first postprandial hour, splanchnic oxygen uptake increased from 62 +/- 5 to 93 +/- 9 mL/min (+50%, P < .05), thereby accounting for 62% +/- 17% of the simultaneous increase in whole-body oxygen consumption. During the second postprandial hour, splanchnic oxygen uptake increased no further, whereas in the extrasplanchnic tissues the oxygen consumption increased, now accounting for the entire simultaneous increase in pulmonary oxygen uptake. Cardiac output increased from basal 6.4 +/- 0.4 to 7.5 +/- 0.5 L/min. Splanchnic blood flow changed little while the arteriohepatic venous oxygen difference increased from 46 +/- 3 to 54 +/- 4 mL/L. Arterial and hepatic venous blood temperatures increased by almost 0.3 degrees C, reflecting a considerable accumulation of heat, indicating a conversion into a positive thermal balance. It is concluded that after protein ingestion, (1) oxygen uptake increases mainly in the splanchnic organs during the first hour, and thereafter exclusively in the extrasplanchnic tissues; (2) the blood flow increases mainly in extrasplanchnic tissues; and (3) the blood temperature increases almost linearly, indicating an upward adjustment of the temperature setpoint in the central thermosensors.
Implications of health reform for retiree health benefits.
Fronstin, Paul
2010-01-01
This Issue Brief examines how current health reform legislation being debated in Congress will impact the future of retiree health benefits. In general, the proposals' provisions will have a mixed impact on retiree health benefits: In the short term, the reinsurance provisions would help shore up early retiree coverage and Medicare Part D coverage would become more valuable to retirees. In the longer term, insurance reform combined with new subsidies for individuals enrolling for coverage through insurance exchanges, the maintenance-of-effort provision affecting early retiree benefits, increases to the cost of providing drug benefits to retirees, and enhanced Medicare Part D coverage, would all create significant incentives for employers to drop coverage for early retirees and drug coverage for Medicare-eligible retirees. REINSURANCE PROGRAM FOR EARLY RETIREES: Proposed legislation includes a provision to create a temporary reinsurance program for employers providing health benefits to retirees over age 55 and not yet eligible for Medicare. Given the temporary nature of the program, it is intended to provide employers an incentive to maintain benefits until the health insurance exchange is fully operational. At that point, employers will have less incentive to provide health benefits to early retirees, and retirees will have less need for former employers to maintain a program. MEDICARE DRUG BENEFITS: The House-passed bill would initially reduce the coverage gap (the so-called "doughnut hole") for individuals in the Medicare Part D program by $500 and eliminate it altogether by 2019. The bill currently before the Senate would also reduce the coverage gap by $500, but does not call for eliminating it. Both would also provide a 50 percent discount to brand-name drug coverage in the coverage gap. These provisions increase the value of the Medicare Part D drug program to Medicare-eligible beneficiaries relative to drug benefits provided by employers. TAX TREATMENT OF EMPLOYER SUBSIDIES UNDER MMA: The Medicare Modernization Act provides subsidies to employers that continue to offer prescription drug coverage through a retiree health benefits program. This subsidy is currently not counted as taxable income to the employer receiving it. Both the House and Senate bills would effectively repeal this tax exclusion. This would have two effects: The real cost of providing retiree health benefits to Medicare-eligible retirees would increase, and an employer's FAS 106 liability would increase immediately. The increase in the cost of retiree drug benefits will cause employers to re-evaluate the subsidy, compared with other available options. Moving retirees to Medicare Part D may become even more attractive to employers if the coverage gap is reduced and/or eliminated. POSTRETIREMENT BENEFIT CHANGES: With some exceptions, the House-passed legislation would prohibit employers from changing the benefits offered to retirees and their beneficiaries once a person has retired. This provision could have a number of different effects: More employers may move toward capping their contributions; employers that want to maintain retiree health benefits may react by cutting the health benefits of active workers; employers may eliminate retiree health benefits altogether to avoid being locked into providing a permanent benefit; or they may drop benefits if they think there is no need to provide them.
2007-02-01
bladder and the rectum are overprotected while the PTV coverage is undesirably reduced. On the other hand, if their maximum dose is increased and/or...B, the bladder and rectum were overprotected with undesirably low PTV coverage (84.54%). The reduction of their weighting factor increased PTV
Supplemental Coverage Associated With More Rapid Spending Growth For Medicare Beneficiaries
Golberstein, Ezra; Walsh, Kayo; He, Yulei; Chernew, Michael E.
2013-01-01
Lowering both Medicare spending and the rate of Medicare spending growth is important for the nation’s fiscal health. Policy makers in search of ways to achieve these reductions have looked at the role that supplemental coverage for Medicare beneficiaries plays in Medicare spending. Supplemental coverage makes health care more affordable for beneficiaries but also makes beneficiaries insensitive to the cost of their care, thereby increasing the demand for care. Ours is the first empirical study to investigate whether supplemental Medicare coverage is associated with higher rates of spending growth over time. We found that supplemental insurance coverage was associated with significantly higher rates of overall spending growth. Specifically, employer-sponsored and self-purchased supplemental coverage were associated with annual total spending growth rates of 7.17 percent and 7.18 percent, respectively, compared to 6.08 percent annual growth for beneficiaries without supplemental coverage. Results for Medicare program spending were more equivocal, however. Our results are consistent with the belief that current trends away from generous employer-sponsored supplemental coverage and efforts to restrict the generosity of supplemental coverage may slow spending growth. PMID:23650320
Variation in rotavirus vaccine coverage by sub-counties in Kenya.
Wandera, Ernest Apondi; Mohammad, Shah; Ouko, John Odhiambo; Yatitch, James; Taniguchi, Koki; Ichinose, Yoshio
2017-01-01
Rotavirus gastroenteritis is an important cause of childhood morbidity and mortality in Kenya. In July 2014, Kenya introduced the rotavirus vaccine into her national immunization program. Although immunization coverage is crucial in assessing the real-world impact of this vaccine, variability in the vaccine coverage across the country is likely to occur. In view of this, we estimated the extent of coverage for the rotavirus vaccine at two socio-economically different sub-counties using the administrative data. The findings indicate disparities in vaccine coverage and access between the sub-counties and, thus, underscore the need to strengthen immunization systems to facilitate timely, accessible, and equitable vaccine delivery across the country. Both sub-counties recorded high vaccine dropout, suggestive of poor utilization of the vaccine. In this regard, increased social mobilization is needed to encourage vaccine compliance and to enhance tracking of vaccine defaulters. While efforts to improve the accuracy of the administrative coverage estimates are crucial, vaccination coverage surveys will be needed to verify the administrative coverage data and help identify specific factors relating to rotavirus vaccine coverage in the country.
NASA Astrophysics Data System (ADS)
Fazleev, N. G.; Nadesalingam, M. P.; Maddox, W.; Weiss, A. H.
2011-06-01
Positron annihilation induced Auger electron spectroscopy (PAES) measurements from the surface of an oxidized Cu(100) single crystal show a large increase in the intensity of the annihilation induced Cu M2,3VV Auger peak as the sample is subjected to a series of isochronal anneals in vacuum up to annealing temperature 300 °C. The PAES intensity then decreases monotonically as the annealing temperature is increased to ˜550 °C. Experimental positron annihilation probabilities with Cu 3p and O 1s core electrons are estimated from the measured intensities of the positron annihilation induced Cu M2,3VV and O KLL Auger transitions. PAES results are analyzed by performing calculations of positron surface states and annihilation probabilities of the surface-trapped positrons with relevant core electrons taking into account the charge redistribution at the surface and various surface structures associated with low and high oxygen coverages. The variations in atomic structure and chemical composition of the topmost layers of the oxidized Cu(100) surface are found to affect localization and spatial extent of the positron surface state wave function. The computed positron binding energy and annihilation characteristics reveal their sensitivity to charge transfer effects, atomic structure and chemical composition of the topmost layers of the oxidized Cu(100) surface. Theoretical positron annihilation probabilities with Cu 3p and O 1s core electrons computed for the oxidized Cu(100) surface are compared with experimental ones. The obtained results provide a demonstration of thermal reduction of the copper oxide surface after annealing at 300 °C followed by re-oxidation of the Cu(100) surface at higher annealing temperatures presumably due to diffusion of subsurface oxygen to the surface.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fazleev, N. G.; Department of Physics, Kazan State University, Kazan 420008; Nadesalingam, M. P.
2011-06-01
Positron annihilation induced Auger electron spectroscopy (PAES) measurements from the surface of an oxidized Cu(100) single crystal show a large increase in the intensity of the annihilation induced Cu M2,3VV Auger peak as the sample is subjected to a series of isochronal anneals in vacuum up to annealing temperature 300 deg. C. The PAES intensity then decreases monotonically as the annealing temperature is increased to {approx}550 deg. C. Experimental positron annihilation probabilities with Cu 3p and O 1s core electrons are estimated from the measured intensities of the positron annihilation induced Cu M{sub 2,3}VV and O KLL Auger transitions. PAESmore » results are analyzed by performing calculations of positron surface states and annihilation probabilities of the surface-trapped positrons with relevant core electrons taking into account the charge redistribution at the surface and various surface structures associated with low and high oxygen coverages. The variations in atomic structure and chemical composition of the topmost layers of the oxidized Cu(100) surface are found to affect localization and spatial extent of the positron surface state wave function. The computed positron binding energy and annihilation characteristics reveal their sensitivity to charge transfer effects, atomic structure and chemical composition of the topmost layers of the oxidized Cu(100) surface. Theoretical positron annihilation probabilities with Cu 3p and O 1s core electrons computed for the oxidized Cu(100) surface are compared with experimental ones. The obtained results provide a demonstration of thermal reduction of the copper oxide surface after annealing at 300 deg. C followed by re-oxidation of the Cu(100) surface at higher annealing temperatures presumably due to diffusion of subsurface oxygen to the surface.« less
NASA Astrophysics Data System (ADS)
Kim, Jae Gon
2017-04-01
Oxidation of sulfides produces acid rock drainage (ARD) upon their exposure to oxidation environment by construction and mining activities. The ARD causes the acidification and metal contamination of soil, surface water and groundwater, the damage of plant, the deterioration of landscape and the reduction of slope stability. The revegetation of slope surface is one of commonly adopted strategies to reduce erosion and to increase slope stability. However, the revegetation of the ARD producing slope surface is frequently failed due to its high acidity and toxic metal content. We developed a revegetation method consisting of microencapsualtion and artificial soil in the laboratory. The revegetation method was applied on the ARD producing slope on which the revegetation using soil coverage and seeding was failed and monitored the plant growth for one year. The phosphate solution was applied on sulfide containing rock to form stable Fe-phosphate mineral on the surface of sulfide, which worked as a physical barrier to prevent contacting oxidants such as oxygen and Fe3+ ion to the sulfide surface. After the microencapsulation, two artificial soil layers were constructed. The first layer containing organic matter, dolomite powder and soil was constructed at 2 cm thickness to neutralize the rising acidic capillary water from the subsurface and to remove the dissolved oxygen from the percolating rain water. Finally, the second layer containing seeds, organic matter, nutrients and soil was constructed at 3 cm thickness on the top. After application of the method, the pH of the soil below the artificial soil layer increased and the ARD production from the rock fragments reduced. The plant growth showed an ordinary state while the plant died two month after germination for the previous revegetation trial. No soil erosion occurred from the slope during the one year field test.
Gain in Insurance Coverage and Residual Uninsurance Under the Affordable Care Act: Texas, 2013-2016.
Pickett, Stephen; Marks, Elena; Ho, Vivian
2017-01-01
To examine the effects of the Affordable Care Act's (ACA's) Marketplace on Texas residents and determine which population subgroups benefited the most and which the least. We analyzed insurance coverage rates among nonelderly Texas adults using the Health Reform Monitoring Survey-Texas from September 2013, just before the first open enrollment period in the Marketplace, through March 2016. Texas has experienced a roughly 6-percentage-point increase in insurance coverage (from 74.7% to 80.6%; P = .012) after implementation of the major insurance provisions of the ACA. The 4 subgroups with the largest increases in adjusted insurance coverage between 2013 and 2016 were persons aged 50 to 64 years (12.1 percentage points; P = .002), Hispanics (10.9 percentage points; P = .002), persons reporting fair or poor health status (10.2 percentage points; P = .038), and those with a high school diploma as their highest educational attainment (9.2 percentage points; P = .023). Many population subgroups have benefited from the ACA's Marketplace, but approximately 3 million Texas residents still lack health coverage. Adopting the ACA's Medicaid expansion is a means to address the lack of coverage.
Sheils, John F; Haught, Randall
2011-11-01
Many policy analysts fear that eliminating the individual health insurance mandate and penalty from the Affordable Care Act of 2010 would lead to a "premium spiral," in which healthy people would drop coverage, premiums would soar, and the number of people with coverage would plummet. However, there are other provisions of the law that would greatly mitigate this effect. For example, the subsidies provided in the law to help people purchase coverage through health insurance exchanges would restrain a premium spiral by absorbing much of the impact of premium increases. We estimate that if the mandate were lifted, premiums in the individual market would increase by 12.6 percent-somewhat less than other estimates-with 7.8 million people losing coverage, versus other estimates for coverage loss of 16-24 million people. In sum, the Affordable Care Act would still cover 23 million people who would have been uninsured without the law. Our study suggests that although the mandate would have important effects on premiums and coverage, it might not be essential to the act's successful implementation.
NASA Astrophysics Data System (ADS)
Meena, Shweta; Choudhary, Sudhanshu
2017-12-01
Spin polarized properties of fluorinated graphene as tunnel barrier with CrO2 as two HMF electrodes are studied using first principle methods based on density functional theory. Fluorinated graphene with different fluorine coverages is explored as tunnel barriers in magnetic tunnel junctions. Density functional computation for different fluorine coverages imply that with increase in fluorine coverages, there is increase in band gap (Eg) of graphene, Eg ˜ 3.466 e V was observed when graphene sheet is fluorine adsorbed on both-side with 100% coverage (CF). The results of CF graphene are compared with C4F (fluorination on one-side of graphene sheet with 25% coverage) and out-of-plane graphene based magnetic tunnel junctions. On comparison of the results it is observed that CF graphene based structure offers high TMR ˜100%, and the transport of carrier is through tunneling as there are no transmission states near Fermi level. This suggests that graphene sheet with both-side fluorination with 100% coverages acts as a perfect insulator and hence a better barrier to the carriers which is due to negligible spin down current (I ↓ ) in both Parallel Configuration (PC) and Antiparallel Configuration (APC).
NASA Astrophysics Data System (ADS)
Fazleev, N. G.; Olenga, Antoine; Weiss, A. H.
2013-03-01
The process by which oxide layers are formed on metal surfaces is still not well understood. In this work we present the results of theoretical studies of positron states and annihilation characteristics of surface-trapped positrons at the oxidized Cu(110) surface. An ab-initio investigation of stability and associated electronic properties of different adsorption phases of oxygen on Cu(110) has been performed on the basis of density functional theory and using DMOl3 code. The changes in the positron work function and the surface dipole moment when oxygen atoms occupy on-surface and sub-surface sites have been attributed to charge redistribution within the first two layers, buckling effects within each layer and interlayer expansion. The computed positron binding energy, positron surface state wave function, and annihilation probabilities of surface trapped positrons with relevant core electrons demonstrate their sensitivity to oxygen coverage, elemental content, atomic structure of the topmost layers of surfaces, and charge transfer effects. Theoretical results are compared with experimental data obtained from studies of oxidized transition metal surfaces using positron annihilation induced Auger electron spectroscopy. This work was supported in part by the National Science Foundation Grant DMR-0907679.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Detwiler, Michael D.; Majumdar, Paulami; Gu, Xiang-Kui
Changes in surface chemistry and morphology of Re–Pt surfaces synthesized by ultra-high vacuum chemical vapor deposition (UHV-CVD) of Re on Pt(111) were studied by a combination of experiment and density functional theory (DFT) modeling. A Re oxide formed following exposure of the as-deposited Re to 1 × 10- 6 mbar oxygen at 600–673 K. Subsequent annealing at 973 K resulted in oxygen desorption and a decrease in Re coverage, as calculated by XPS and as observed by STM. This observation was explained by DFT calculations which showed that a clean Pt surface slab with subsurface Re is thermodynamically more favorablemore » than Pt(111) with Re on the surface. DFT calculations also predicted weaker O and CO binding on this surface compared to both monometallic Pt and Re, and HREELS and temperature desorption measurements suggested that O binds weakly to the Pt skin surface, with oxygen on the Pt skin desorbing from this surface following annealing at 373 K. Trends in adsorption energies were consistent with DFT calculated d-band centers of surface atoms for model Pt–Re structures. Comparison of HREELS data and STM images with DFT calculated vibrational frequencies have been used to understand the structure of rhenium oxide on Pt(111).« less
Biofilm formation in geometries with different surface curvature and oxygen availability
NASA Astrophysics Data System (ADS)
Chang, Ya-Wen; Fragkopoulos, Alexandros A.; Marquez, Samantha M.; Kim, Harold D.; Angelini, Thomas E.; Fernández-Nieves, Alberto
2015-03-01
Bacteria in the natural environment exist as interface-associated colonies known as biofilms . Complex mechanisms are often involved in biofilm formation and development. Despite the understanding of the molecular mechanisms involved in biofilm formation, it remains unclear how physical effects in standing cultures influence biofilm development. The topology of the solid interface has been suggested as one of the physical cues influencing bacteria-surface interactions and biofilm development. Using the model organism Bacillus subtilis, we study the transformation of swimming bacteria in liquid culture into robust biofilms in a range of confinement geometries (planar, spherical and toroidal) and interfaces (air/water, silicone/water, and silicone elastomer/water). We find that B. subtilis form submerged biofilms at both solid and liquid interfaces in addition to air-water pellicles. When confined, bacteria grow on curved surfaces of both positive and negative Gaussian curvature. However, the confinement geometry does affect the resulting biofilm roughness and relative coverage. We also find that the biofilm location is governed by oxygen availability as well as by gravitational effects; these compete with each other in some situations. Overall, our results demonstrate that confinement geometry is an effective way to control oxygen availability and subsequently biofilm growth.
Garn, Joshua V; Sclar, Gloria D; Freeman, Matthew C; Penakalapati, Gauthami; Alexander, Kelly T; Brooks, Patrick; Rehfuess, Eva A; Boisson, Sophie; Medlicott, Kate O; Clasen, Thomas F
2017-04-01
An estimated 2.4 billion people still lack access to improved sanitation and 946 million still practice open defecation. The World Health Organization (WHO) commissioned this review to assess the impact of sanitation on coverage and use, as part of its effort to develop a set of guidelines on sanitation and health. We systematically reviewed the literature and used meta-analysis to quantitatively characterize how different sanitation interventions impact latrine coverage and use. We also assessed both qualitative and quantitative studies to understand how different structural and design characteristics of sanitation are associated with individual latrine use. A total of 64 studies met our eligibility criteria. Of 27 intervention studies that reported on household latrine coverage and provided a point estimate with confidence interval, the average increase in coverage was 14% (95% CI: 10%, 19%). The intervention types with the largest absolute increases in coverage included the Indian government's "Total Sanitation Campaign" (27%; 95% CI: 14%, 39%), latrine subsidy/provision interventions (16%; 95% CI: 8%, 24%), latrine subsidy/provision interventions that also incorporated education components (17%; 95% CI: -5%, 38%), sewerage interventions (14%; 95% CI: 1%, 28%), sanitation education interventions (14%; 95% CI: 3%, 26%), and community-led total sanitation interventions (12%; 95% CI: -2%, 27%). Of 10 intervention studies that reported on household latrine use, the average increase was 13% (95% CI: 4%, 21%). The sanitation interventions and contexts in which they were implemented varied, leading to high heterogeneity across studies. We found 24 studies that examined the association between structural and design characteristics of sanitation facilities and facility use. These studies reported that better maintenance, accessibility, privacy, facility type, cleanliness, newer latrines, and better hygiene access were all frequently associated with higher use, whereas poorer sanitation conditions were associated with lower use. Our results indicate that most sanitation interventions only had a modest impact on increasing latrine coverage and use. A further understanding of how different sanitation characteristics and sanitation interventions impact coverage and use is essential in order to more effectively attain sanitation access for all, eliminate open defecation, and ultimately improve health. Copyright © 2016 Elsevier GmbH. All rights reserved.
Increasing Cervical Cancer Screening Coverage: A Randomised, Community-Based Clinical Trial
Acera, Amelia; Manresa, Josep Maria; Rodriguez, Diego; Rodriguez, Ana; Bonet, Josep Maria; Trapero-Bertran, Marta; Hidalgo, Pablo; Sànchez, Norman
2017-01-01
Background Opportunistic cervical cancer screening can lead to suboptimal screening coverage. Coverage could be increased after a personalised invitation to the target population. We present a community randomized intervention study with three strategies aiming to increase screening coverage. Methods The CRICERVA study is a community-based clinical trial to improve coverage of population-based screening in the Cerdanyola SAP area in Barcelona.A total of 32,858 women residing in the study area, aged 30 to 70 years were evaluated. A total of 15,965 women were identified as having no registration of a cervical cytology in the last 3.5 years within the Public Health data base system. Eligible women were assigned to one of four community randomized intervention groups (IGs): (1) (IG1 N = 4197) personalised invitation letter, (2) (IG2 N = 3601) personalised invitation letter + informative leaflet, (3) (IG3 N = 6088) personalised invitation letter + informative leaflet + personalised phone call and (4) (Control N = 2079) based on spontaneous demand of cervical cancer screening as officially recommended. To evaluate screening coverage, we used heterogeneity tests to compare impact of the interventions and mixed logistic regression models to assess the age effect. We refer a “rescue” visit as the screening visit resulting from the study invitation. Results Among the 13,886 women in the IGs, 2,862 were evaluated as having an adequate screening history after the initial contact; 4,263 were lost to follow-up and 5,341 were identified as having insufficient screening and thus being eligible for a rescue visit. All intervention strategies significantly increased participation to screening compared to the control group. Coverage after the intervention reached 84.1% while the control group reached 64.8%. The final impact of our study was an increase of 20% in the three IGs and of 9% in the control group (p<0.001). Within the intervention arms, age was an important determinant of rescue visits showing a statistical interaction with the coverage attained in the IGs. Within the intervention groups, final screening coverage was significantly higher in IG3 (84.4%) (p<0.001). However, the differences were more substantial in the age groups 50–59 and those 60+. The highest impact of the IG3 intervention was observed among women 60+ y.o with 32.0% of them being rescued for screening. The lowest impact of the interventions was in younger women. Conclusions The study confirms that using individual contact methods and assigning a fixed screening date notably increases participation in screening. The response to the invitation is strongly dependent on age. Trial Registration ClinicalTrials.gov NCT01373723 PMID:28118410
Arefi, Hadi H; Nolan, Michael; Fagas, Giorgos
2014-11-11
Surface modification of silicon with organic monolayers tethered to the surface by different linkers is an important process in realizing future miniaturized electronic and sensor devices. Understanding the roles played by the nature of the linking group and the chain length on the adsorption structures and stabilities of these assemblies is vital to advance this technology. This paper presents a density functional theory (DFT) study of the hydrogen passivated Si(111) surface modified with alkyl chains of the general formula H:Si-(CH2)n-CH2 and H:Si-X-(CH2)n-CH3, where X = NH, O, S and n = (0, 1, 3, 5, 7, 9, 11), at half coverage. For (X)-hexane and (X)-dodecane functionalization, we also examined various coverages up to full monolayer grafting in order to validate the result of half covered surface and the linker effect on the coverage. We find that it is necessary to take into account the van der Waals interaction between the alkyl chains. The strongest binding is for the oxygen linker, followed by S, N, and C, irrespective of chain length. The result revealed that the sequence of the stability is independent of coverage; however, linkers other than carbon can shift the optimum coverage considerably and allow further packing density. For all linkers apart from sulfur, structural properties, in particular, surface-linker-chain angles, saturate to a single value once n > 3. For sulfur, we identify three regimes, namely, n = 0-3, n = 5-7, and n = 9-11, each with its own characteristic adsorption structures. Where possible, our computational results are shown to be consistent with the available experimental data and show how the fundamental structural properties of modified Si surfaces can be controlled by the choice of linking group and chain length.
Carolan, Michael Francis [Allentown, PA; Bernhart, John Charles [Fleetwood, PA
2012-08-21
Method for processing an article comprising mixed conducting metal oxide material. The method comprises contacting the article with an oxygen-containing gas and either reducing the temperature of the oxygen-containing gas during a cooling period or increasing the temperature of the oxygen-containing gas during a heating period; during the cooling period, reducing the oxygen activity in the oxygen-containing gas during at least a portion of the cooling period and increasing the rate at which the temperature of the oxygen-containing gas is reduced during at least a portion of the cooling period; and during the heating period, increasing the oxygen activity in the oxygen-containing gas during at least a portion of the heating period and decreasing the rate at which the temperature of the oxygen-containing gas is increased during at least a portion of the heating period.
Evaluating the Ozioma cancer news service: A community randomized trial in 24 U.S. cities
Caburnay, Charlene A.; Luke, Douglas A.; Cameron, Glen T.; Cohen, Elisia L.; Fu, Qiang; Lai, Choi L.; Stemmle, Jonathan; Paulen, Melissa; McDaniels-Jackson, Lillie; Kreuter, Matthew W.
2012-01-01
Objective This community randomized trial evaluated effects of the Ozioma News Service on the amount and quality of cancer coverage in Black weekly newspapers in 24 U.S. cities. Method We created and operated Ozioma, the first cancer information news service specifically for Black newspapers. Over 21 months, Ozioma developed community- and race-specific cancer news releases for each of 12 Black weekly newspapers in intervention communities. Cancer coverage in these papers was tracked before and during the intervention and compared to 12 Black newspapers in control communities. Results From 2004-2007, we coded 9,257 health and cancer stories from 3,178 newspaper issues. Intervention newspapers published approximately 4 times the expected number of cancer stories compared to control newspapers (p12&21mo<.01), and also saw an increase in graphics (p12&21mo<.01), local relevance (p12mo=.01), and personal mobilization (p12mo<.10). However, this increased coverage supplanted other health topics and had smaller graphics (NS), had less community mobilization (p21mo=.01), and less likely to be from a local source (NS). Conclusion Providing news releases with localized and race-specific features to minority-serving media outlets can increase the quantity of cancer coverage. Results are mixed for the journalistic and public health quality of this increased cancer coverage in Black newspapers. PMID:22546317
Analysis of error in TOMS total ozone as a function of orbit and attitude parameters
NASA Technical Reports Server (NTRS)
Gregg, W. W.; Ardanuy, P. E.; Braun, W. C.; Vallette, B. J.; Bhartia, P. K.; Ray, S. N.
1991-01-01
Computer simulations of orbital scenarios were performed to examine the effects of orbital altitude, equator crossing time, attitude uncertainty, and orbital eccentricity on ozone observations by future satellites. These effects were assessed by determining changes in solar and viewing geometry and earth daytime coverage loss. The importance of these changes on ozone retrieval was determined by simulating uncertainties in the TOMS ozone retrieval algorithm. The major findings are as follows: (1) Drift of equator crossing time from local noon would have the largest effect on the quality of ozone derived from TOMS. The most significant effect of this drift is the loss of earth daytime coverage in the winter hemisphere. The loss in coverage increases from 1 degree latitude for + or - 1 hour from noon, 6 degrees for + or - 3 hours from noon, to 53 degrees for + or - 6 hours from noon. An additional effect is the increase in ozone retrieval errors due to high solar zenith angles. (2) To maintain contiguous earth coverage, the maximum scan angle of the sensor must be increased with decreasing orbital altitude. The maximum scan angle required for full coverage at the equator varies from 60 degrees at 600 km altitude to 45 degrees at 1200 km. This produces an increase in spacecraft zenith angle, theta, which decreases the ozone retrieval accuracy. The range in theta was approximately 72 degrees for 600 km to approximately 57 degrees at 1200 km. (3) The effect of elliptical orbits is to create gaps in coverage along the subsatellite track. An elliptical orbit with a 200 km perigee and 1200 km apogee produced a maximum earth coverage gap of about 45 km at the perigee at nadir. (4) An attitude uncertainty of 0.1 degree in each axis (pitch, roll, yaw) produced a maximum scan angle to view the pole, and maximum solar zenith angle).
Wehby, George L; Murray, Jeffrey C; McCarthy, Ann Marie; Castilla, Eduardo E
2011-12-01
OBJECTIVE. To evaluate the extent of racial gaps in child health insurance coverage in South America and study the contribution of wealth, human capital, and other household characteristics to accounting for racial disparities in insurance coverage. DATA SOURCES/STUDY SETTING. Primary data collected between 2005 and 2006 in 30 pediatric practices in Argentina, Brazil, Ecuador, and Chile. DESIGN. Country-specific regression models are used to assess differences in insurance coverage by race. A decomposition model is used to quantify the extent to which wealth, human capital, and other household characteristics account for racial disparities in insurance coverage. DATA COLLECTION/EXTRACTION METHODS. In-person interviews were conducted with the mothers of 2,365 children. PRINCIPAL FINDINGS. The majority of children have no insurance coverage except in Chile. Large racial disparities in insurance coverage are observed. Household wealth is the single most important household-level factor accounting for racial disparities in coverage and is significantly and positively associated with coverage, followed by maternal education and employment/occupational status. Geographic differences account for the largest part of racial disparities in insurance coverage in Argentina and Ecuador. CONCLUSIONS. Increasing the coverage of children in less affluent families is important for reducing racial gaps in health insurance coverage in the study countries. © Health Research and Educational Trust.
Adsorption isotherms and kinetics of activated carbons produced from coals of different ranks.
Purevsuren, B; Lin, Chin-Jung; Davaajav, Y; Ariunaa, A; Batbileg, S; Avid, B; Jargalmaa, S; Huang, Yu; Liou, Sofia Ya-Hsuan
2015-01-01
Activated carbons (ACs) from six coals, ranging from low-rank lignite brown coal to high-rank stone coal, were utilized as adsorbents to remove basic methylene blue (MB) from an aqueous solution. The surface properties of the obtained ACs were characterized via thermal analysis, N2 isothermal sorption, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Boehm titration. As coal rank decreased, an increase in the heterogeneity of the pore structures and abundance of oxygen-containing functional groups increased MB coverage on its surface. The equilibrium data fitted well with the Langmuir model, and adsorption capacity of MB ranged from 51.8 to 344.8 mg g⁻¹. Good correlation coefficients were obtained using the intra-particle diffusion model, indicating that the adsorption of MB onto ACs is diffusion controlled. The values of the effective diffusion coefficient ranged from 0.61 × 10⁻¹⁰ to 7.1 × 10⁻¹⁰ m² s⁻¹, indicating that ACs from lower-rank coals have higher effective diffusivities. Among all the ACs obtained from selected coals, the AC from low-rank lignite brown coal was the most effective in removing MB from an aqueous solution.
Tang, Yee-Chin; Katsuma, Shoji; Fujimoto, Shinji; Hiromoto, Sachiko
2006-11-01
The electrochemical corrosion behaviour of Type 304 and 316L stainless steels was studied in Hanks' solution, Eagle's minimum essential medium (MEM), serum containing medium (MEM with 10% of fetal bovine serum) without cells, and serum containing medium with cells over a 1-week period. Polarization resistance measurements indicated that the stainless steels were resistant to Hanks' and MEM solutions. Type 304 was more susceptible to pitting corrosion than Type 316L in Hanks' and MEM solutions. The uniform corrosion resistance of stainless steels, determined by R(p), was lower in culturing medium than in Hanks' and MEM. The low corrosion resistance was due to surface passive film with less protective to reveal high anodic dissolution rate. When cells were present, the initial corrosion resistance was low, but gradually increased after 3 days, consistent with the trend of cell coverage. The presence of cells was found to suppress the cathodic reaction, that is, oxygen reduction, and increase the uniform corrosion resistance as a consequence. On the other hand, both Type 304 and 316L stainless steels became more susceptible to pitting corrosion when they were covered with cells.
Hypoxia adaptations in the grey wolf (Canis lupus chanco) from Qinghai-Tibet Plateau.
Zhang, Wenping; Fan, Zhenxin; Han, Eunjung; Hou, Rong; Zhang, Liang; Galaverni, Marco; Huang, Jie; Liu, Hong; Silva, Pedro; Li, Peng; Pollinger, John P; Du, Lianming; Zhang, XiuyYue; Yue, Bisong; Wayne, Robert K; Zhang, Zhihe
2014-07-01
The Tibetan grey wolf (Canis lupus chanco) occupies habitats on the Qinghai-Tibet Plateau, a high altitude (>3000 m) environment where low oxygen tension exerts unique selection pressure on individuals to adapt to hypoxic conditions. To identify genes involved in hypoxia adaptation, we generated complete genome sequences of nine Chinese wolves from high and low altitude populations at an average coverage of 25× coverage. We found that, beginning about 55,000 years ago, the highland Tibetan grey wolf suffered a more substantial population decline than lowland wolves. Positively selected hypoxia-related genes in highland wolves are enriched in the HIF signaling pathway (P = 1.57E-6), ATP binding (P = 5.62E-5), and response to an oxygen-containing compound (P≤5.30E-4). Of these positively selected hypoxia-related genes, three genes (EPAS1, ANGPT1, and RYR2) had at least one specific fixed non-synonymous SNP in highland wolves based on the nine genome data. Our re-sequencing studies on a large panel of individuals showed a frequency difference greater than 58% between highland and lowland wolves for these specific fixed non-synonymous SNPs and a high degree of LD surrounding the three genes, which imply strong selection. Past studies have shown that EPAS1 and ANGPT1 are important in the response to hypoxic stress, and RYR2 is involved in heart function. These three genes also exhibited significant signals of natural selection in high altitude human populations, which suggest similar evolutionary constraints on natural selection in wolves and humans of the Qinghai-Tibet Plateau.
Tiede, L M; Cook, E A; Morsey, B; Fox, H S
2011-12-22
Mitochondrial dysfunction is implicated in a majority of neurodegenerative disorders and much study of neurodegenerative disease is done on cultured neurons. In traditional tissue culture, the oxygen level that cells experience is dramatically higher (21%) than in vivo conditions (1-11%). These differences can alter experimental results, especially, pertaining to mitochondria and oxidative metabolism. Our results show that primary neurons cultured at physiological oxygen levels found in the brain showed higher polarization, lower rates of ROS production, larger mitochondrial networks, greater cytoplasmic fractions of mitochondria and larger mitochondrial perimeters than those cultured at higher oxygen levels. Although neurons cultured in either physiological oxygen or atmospheric oxygen exhibit significant increases in mitochondrial reactive oxygen species (ROS) production when treated with the human immunodeficiency virus (HIV) virotoxin trans-activator of transcription, mitochondria of neurons cultured at physiological oxygen underwent depolarization with dramatically increased cell death, whereas those cultured at atmospheric oxygen became hyperpolarized with no increase in cell death. Studies with a second HIV virotoxin, negative regulation factor (Nef), revealed that Nef treatment also increased mitochondrial ROS production for both the oxygen conditions, but resulted in mitochondrial depolarization and increased death only in neurons cultured in physiological oxygen. These results indicate a role for oxidative metabolism in a mechanism of neurotoxicity during HIV infection and demonstrate the importance of choosing the correct, physiological, culture oxygen in mitochondrial studies performed in neurons.
Primary care practice and health professional determinants of immunisation coverage.
Grant, Cameron C; Petousis-Harris, Helen; Turner, Nikki; Goodyear-Smith, Felicity; Kerse, Ngaire; Jones, Rhys; York, Deon; Desmond, Natalie; Stewart, Joanna
2011-08-01
To identify primary care factors associated with immunisation coverage. A survey during 2005-2006 of a random sample of New Zealand primary care practices, with over-sampling of practices serving indigenous children. An immunisation audit was conducted for children registered at each practice. Practice characteristics and the knowledge and attitudes of doctors, nurses and caregivers were measured. Practice immunisation coverage was defined as the percentage of registered children from 6 weeks to 23 months old at each practice who were fully immunised for age. Associations of practice, doctor, nurse and caregiver factors with practice immunisation coverage were determined using multiple regression analyses. One hundred and twenty-four (61%) of 205 eligible practices were recruited. A median (25th-75th centile) of 71% (57-77%) of registered children at each practice was fully immunised. In multivariate analyses, immunisation coverage was higher at practices with no staff shortages (median practice coverage 76% vs 67%, P = 0.004) and where doctors were confident in their immunisation knowledge (72% vs 67%, P= 0.005). Coverage was lower if the children's parents had received information antenatally, which discouraged immunisation (67% vs 73%, P = 0.008). Coverage decreased as socio-economic deprivation of the registered population increased (P < 0.001) and as the children's age (P = 0.001) and registration age (P = 0.02) increased. CONCLUSIONS Higher immunisation coverage is achieved by practices that establish an early relationship with the family and that are adequately resourced with stable and confident staff. Immunisation promotion should begin antenatally. © 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).
Pezzoli, Lorenzo; Andrews, Nick; Ronveaux, Olivier
2010-05-01
Vaccination programmes targeting disease elimination aim to achieve very high coverage levels (e.g. 95%). We calculated the precision of different clustered lot quality assurance sampling (LQAS) designs in computer-simulated surveys to provide local health officers in the field with preset LQAS plans to simply and rapidly assess programmes with high coverage targets. We calculated sample size (N), decision value (d) and misclassification errors (alpha and beta) of several LQAS plans by running 10 000 simulations. We kept the upper coverage threshold (UT) at 90% or 95% and decreased the lower threshold (LT) progressively by 5%. We measured the proportion of simulations with < or =d individuals unvaccinated or lower if the coverage was set at the UT (pUT) to calculate beta (1-pUT) and the proportion of simulations with >d unvaccinated individuals if the coverage was LT% (pLT) to calculate alpha (1-pLT). We divided N in clusters (between 5 and 10) and recalculated the errors hypothesising that the coverage would vary in the clusters according to a binomial distribution with preset standard deviations of 0.05 and 0.1 from the mean lot coverage. We selected the plans fulfilling these criteria: alpha < or = 5% beta < or = 20% in the unclustered design; alpha < or = 10% beta < or = 25% when the lots were divided in five clusters. When the interval between UT and LT was larger than 10% (e.g. 15%), we were able to select precise LQAS plans dividing the lot in five clusters with N = 50 (5 x 10) and d = 4 to evaluate programmes with 95% coverage target and d = 7 to evaluate programmes with 90% target. These plans will considerably increase the feasibility and the rapidity of conducting the LQAS in the field.
ERIC Educational Resources Information Center
Selden, Thomas M.
2009-01-01
The share of health insurance premiums that self-employed workers can deduct when computing federal income taxes rose from 30 percent in 1996 to 100 percent in 2003. Data from the 1996-2004 Medical Expenditure Panel Survey are used to show that the increased tax subsidy was associated with substantial increases in private coverage among…
Manuel, D G; Ho, T H; Harper, S; Anderson, G M; Lynch, J; Rosella, L C
2014-07-01
Most individual preventive therapies potentially narrow or widen health disparities depending on the difference in community effectiveness across socioeconomic position (SEP). The equity tipping point (defined as the point at which health disparities become larger) can be calculated by varying components of community effectiveness such as baseline risk of disease, intervention coverage and/or intervention efficacy across SEP. We used a simple modelling approach to estimate the community effectiveness of diabetes prevention across SEP in Canada under different scenarios of intervention coverage. Five-year baseline diabetes risk differed between the lowest and highest income groups by 1.76%. Assuming complete coverage across all income groups, the difference was reduced to 0.90% (144 000 cases prevented) with lifestyle interventions and 1.24% (88 100 cases prevented) with pharmacotherapy. The equity tipping point was estimated to be a coverage difference of 30% for preventive interventions (100% and 70% coverage among the highest and lowest income earners, respectively). Disparities in diabetes risk could be measurably reduced if existing interventions were equally adopted across SEP. However, disparities in coverage could lead to increased inequity in risk. Simple modelling approaches can be used to examine the community effectiveness of individual preventive interventions and their potential to reduce (or increase) disparities. The equity tipping point can be used as a critical threshold for disparities analyses.
Park, Boyoung; Lee, Yeon-Kyeng; Cho, Lisa Y.; Go, Un Yeong; Yang, Jae Jeong; Ma, Seung Hyun; Choi, Bo-Youl; Lee, Moo-Sik; Lee, Jin-Seok; Choi, Eun Hwa; Lee, Hoan Jong
2011-01-01
This study compared interview and telephone surveys to select the better method for regularly estimating nationwide vaccination coverage rates in Korea. Interview surveys using multi-stage cluster sampling and telephone surveys using stratified random sampling were conducted. Nationwide coverage rates were estimated in subjects with vaccination cards in the interview survey. The interview survey relative to the telephone survey showed a higher response rate, lower missing rate, higher validity and a less difference in vaccination coverage rates between card owners and non-owners. Primary vaccination coverage rate was greater than 90% except for the fourth dose of DTaP (diphtheria/tetanus/pertussis), the third dose of polio, and the third dose of Japanese B encephalitis (JBE). The DTaP4: Polio3: MMR1 fully vaccination rate was 62.0% and BCG1:HepB3:DTaP4:Polio3:MMR1 was 59.5%. For age-appropriate vaccination, the coverage rate was 50%-80%. We concluded that the interview survey was better than the telephone survey. These results can be applied to countries with incomplete registry and decreasing rates of landline telephone coverage due to increased cell phone usage and countries. Among mandatory vaccines, efforts to increase vaccination rate for the fourth dose of DTaP, the third dose of polio, JBE and regular vaccinations at recommended periods should be conducted in Korea. PMID:21655054
McMorrow, Stacey; Kenney, Genevieve M; Long, Sharon K; Goin, Dana E
2016-08-01
To assess the effects of past Medicaid eligibility expansions to parents on coverage, access to care, out-of-pocket (OOP) spending, and mental health outcomes, and consider implications for the Affordable Care Act (ACA) Medicaid expansion. Person-level data from the National Health Interview Survey (1998-2010) is used to measure insurance coverage and related outcomes for low-income parents. Using state identifiers available at the National Center for Health Statistics Research Data Center, we attach state Medicaid eligibility thresholds for parents collected from a variety of sources to NHIS observations. We use changes in the Medicaid eligibility threshold for parents within states over time to identify the effects of changes in eligibility on low-income parents. We find that expanding Medicaid eligibility increases insurance coverage, reduces unmet needs due to cost and OOP spending, and improves mental health status among low-income parents. Moreover, our findings suggest that uninsured populations in states not currently participating in the ACA Medicaid expansion would experience even larger improvements in coverage and related outcomes than those in participating states if they chose to expand eligibility. The ACA Medicaid expansion has the potential to improve a wide variety of coverage, access, financial, and health outcomes for uninsured parents in states that choose to expand coverage. © Health Research and Educational Trust.
Exploring the relationship between population density and maternal health coverage.
Hanlon, Michael; Burstein, Roy; Masters, Samuel H; Zhang, Raymond
2012-11-21
Delivering health services to dense populations is more practical than to dispersed populations, other factors constant. This engenders the hypothesis that population density positively affects coverage rates of health services. This hypothesis has been tested indirectly for some services at a local level, but not at a national level. We use cross-sectional data to conduct cross-country, OLS regressions at the national level to estimate the relationship between population density and maternal health coverage. We separately estimate the effect of two measures of density on three population-level coverage rates (6 tests in total). Our coverage indicators are the fraction of the maternal population completing four antenatal care visits and the utilization rates of both skilled birth attendants and in-facility delivery. The first density metric we use is the percentage of a population living in an urban area. The second metric, which we denote as a density score, is a relative ranking of countries by population density. The score's calculation discounts a nation's uninhabited territory under the assumption those areas are irrelevant to service delivery. We find significantly positive relationships between our maternal health indicators and density measures. On average, a one-unit increase in our density score is equivalent to a 0.2% increase in coverage rates. Countries with dispersed populations face higher burdens to achieve multinational coverage targets such as the United Nations' Millennial Development Goals.
Harris, Michael; Alzua, Maria Laura; Osbert, Nicolas; Pickering, Amy
2017-06-20
Sanitation access can provide positive externalities; for example, safe disposal of feces by one household prevents disease transmission to households nearby. However, little empirical evidence exists to characterize the potential health benefits from sanitation externalities. This study investigated the effect of community sanitation coverage versus individual household sanitation access on child health and drinking water quality. Using a census of 121 villages in rural Mali, we analyzed the association of community latrine coverage (defined by a 200 m radius surrounding a household) and individual household latrine ownership with child growth and household stored water quality. Child height-for-age had a significant and positive linear relationship with community latrine coverage, while child weight-for-age and household water quality had nonlinear relationships that leveled off above 60% coverage (p < 0.01; generalized additive models). Child growth and water quality were not associated with individual household latrine ownership. The relationship between community latrine coverage and child height was strongest among households without a latrine; for these households, each 10% increase in latrine coverage was associated with a 0.031 (p-value = 0.040) increase in height-for-age z-score. In this study, the level of sanitation access of surrounding households was more important than private latrine access for protecting water quality and child health.
Exposure-response relationship of neighbourhood sanitation and children's diarrhoea.
Jung, Youngmee Tiffany; Lou, Wendy; Cheng, Yu-Ling
2017-07-01
To assess the association of neighbourhood sanitation coverage with under-five children's diarrhoeal morbidity and to evaluate its exposure-response relationship. We used the Demographic and Health Surveys (DHS) of 29 developing countries in sub-Saharan Africa and South Asia, conducted between 2010 and 2014. The primary outcome was two-week incidence of diarrhoea in children under 5 years of age (N = 269014). We conducted three-level logistic regression analyses and applied cubic splines to assess the trend between neighbourhood-level coverage of improved household sanitation and diarrhoeal morbidity. A significant association between neighbourhood-level coverage of improved household sanitation and diarrhoeal morbidity (OR [95% CI] = 0.68 [0.62-0.76]) was found. Exposure-relationship analyses results showed improved sanitation coverage threshold at 0.6. We found marginal degree of association (OR [95% CI] = 0.82 [0.77-0.87]) below the threshold, which, beyond the threshold, sharply increased to OR of 0.44 (95% CI: 0.29-0.67) at sanitation coverage of 1 (i.e. neighbourhood-wide use of improved household sanitation). Similar exposure-response trends were identified for urban and rural subgroups. Our findings suggest that neighbourhood sanitation plays a key role in reducing diarrhoeal diseases and that increase in sanitation coverage may only have minimal impact on diarrhoeal illness, unless sufficiently high coverage is achieved. © 2017 John Wiley & Sons Ltd.
2017-01-01
Sanitation access can provide positive externalities; for example, safe disposal of feces by one household prevents disease transmission to households nearby. However, little empirical evidence exists to characterize the potential health benefits from sanitation externalities. This study investigated the effect of community sanitation coverage versus individual household sanitation access on child health and drinking water quality. Using a census of 121 villages in rural Mali, we analyzed the association of community latrine coverage (defined by a 200 m radius surrounding a household) and individual household latrine ownership with child growth and household stored water quality. Child height-for-age had a significant and positive linear relationship with community latrine coverage, while child weight-for-age and household water quality had nonlinear relationships that leveled off above 60% coverage (p < 0.01; generalized additive models). Child growth and water quality were not associated with individual household latrine ownership. The relationship between community latrine coverage and child height was strongest among households without a latrine; for these households, each 10% increase in latrine coverage was associated with a 0.031 (p-value = 0.040) increase in height-for-age z-score. In this study, the level of sanitation access of surrounding households was more important than private latrine access for protecting water quality and child health. PMID:28514143
Marton, James; Ketsche, Patricia G; Snyder, Angela; Adams, E Kathleen; Zhou, Mei
2015-01-01
Objective To estimate the effect of premium increases on the probability that near-poor and moderate-income children disenroll from public coverage. Data Sources Enrollment, eligibility, and claims data for Georgia's PeachCare for Kids™ (CHIP) program for multiple years. Study Design We exploited policy-induced variation in premiums generated by cross-sectional differences and changes over time in enrollee age, family size, and income to estimate the duration of enrollment as a function of the effective (per child) premium. We classify children as being of low, medium, or high illness severity. Principal Findings A dollar increase in the per-child premium is associated with a slight increase in a typical child's monthly probability of exiting coverage from 7.70 to 7.83 percent. Children with low illness severity have a significantly higher monthly baseline probability of exiting than children with medium or high illness severity, but the enrollment response to premium increases is similar across all three groups. Conclusions Success in achieving coverage gains through public programs is tempered by persistent problems in maintaining enrollment, which is modestly affected by premium increases. Retention is subject to adverse selection problems, but premium increases do not appear to significantly magnify the selection problem in this case. PMID:25130764
Sharma, Suneeta
2015-01-01
Introduction Despite widespread gains toward the 5th Millennium Development Goal (MDG), pro-rich inequalities in reproductive health (RH) and maternal health (MH) are pervasive throughout the world. As countries enter the post-MDG era and strive toward UHC, it will be important to monitor the extent to which countries are achieving equity of RH and MH service coverage. This study explores how equity of service coverage differs across countries, and explores what policy factors are associated with a country’s progress, or lack thereof, toward more equitable RH and MH service coverage. Methods We used RH and MH service coverage data from Demographic and Health Surveys (DHS) for 74 countries to examine trends in equity between countries and over time from 1990 to 2014. We examined trends in both relative and absolute equity, and measured relative equity using a concentration index of coverage data grouped by wealth quintile. Through multivariate analysis we examined the relative importance of policy factors, such as political commitment to health, governance, and the level of prepayment, in determining countries’ progress toward greater equity in RH and MH service coverage. Results Relative equity for the coverage of RH and MH services has continually increased across all countries over the past quarter century; however, inequities in coverage persist, in some countries more than others. Multivariate analysis shows that higher education and greater political commitment (measured as the share of government spending allocated to health) were significantly associated with higher equity of service coverage. Neither country income, i.e., GDP per capita, nor better governance were significantly associated with equity. Conclusion Equity in RH and MH service coverage has improved but varies considerably across countries and over time. Even among the subset of countries that are close to achieving the MDGs, progress made on equity varies considerably across countries. Enduring disparities in access and outcomes underpin mounting support for targeted reforms within the broader context of universal health coverage (UHC). PMID:26331846
Mi, S; Zhang, L M
2017-04-12
Objective: We evaluated the effects of administering oxygen through nasal catheters inside the mask or through the mask on percutaneous oxygen partial pressure (PcO(2))and percutaneous carbon dioxide partial pressure (PcCO(2)) during noninvasive positive pressure ventilation (NPPV) to find a better way of administering oxygen, which could increase PcO(2) by increasing the inspired oxygen concentration. Methods: Ten healthy volunteers and 9 patients with chronic obstructive pulmonary disease complicated by type Ⅱ respiratory failure were included in this study. Oxygen was administered through a nasal catheter inside the mask or through the mask (oxygen flow was 3 and 5 L/min) during NPPV. PcO(2) and PcCO(2) were measured to evaluate the effects of administering oxygen through a nasal catheter inside the mask or through the mask, indirectly reflecting the effects of administering oxygen through nasal catheter inside the mask or through the mask on inspired oxygen concentration. Results: Compared to administering oxygen through the mask during NPPV, elevated PcO(2) was measured in administering oxygen through the nasal catheter inside the mask, and the differences were statistically significant ( P <0.05). At the same time, there was no significant change in PcCO(2) ( P >0.05). Conclusion: Administering oxygen through a nasal catheter inside the mask during NPPV increased PcO(2) by increasing the inspired oxygen concentration but did not increase PcCO(2). This method of administering oxygen could conserve oxygen and be suitable for family NPPV. Our results also provided theoretical basis for the development of new masks.
Intentional ethylene glycol poisoning increase after media coverage of antifreeze murders.
Morgan, Brent W; Geller, Robert J; Kazzi, Ziad N
2011-07-01
The media can have a profound impact on human behavior. A sensational murder by ethylene glycol (EG) poisoning occurred in our state. The regional media provided extensive coverage of the murder. We undertook this investigation to evaluate our incidence of EG poisoning during the timeframe of before the first report linking a death to ethylene glycol to shortly after the first murder trial. Descriptive statistics and linear regression were used to describe and analyze the number of EG cases over time. A search of the leading regional newspaper's archives established the media coverage timeline. Between 2000 and 2004, our poison center (PC) handled a steady volume of unintentional exposures to EG [range: 105-123 per year, standard deviation (SD)=7.22]. EG exposures thought to be suicidal in intent increased from 12 cases in 2000 to 121 cases in 2004. In the 19 months prior to the first media report of this story, our PC handled a mean of 1 EG case with suicidal intent per month [range: 0-2, SD=.69]. In the month after the first media report, our PC handled 5 EG cases with suicidal intent. When media coverage was most intense (2004), our PC received a mean of 10 EG suicidal-intent calls per month [range: 5-17, SD=3.55]. Although uncommon, reports of malicious EG poisonings also increased during this same period from 2 in 2000 to 14 in 2004. Media coverage of stories involving poisonings may result in copycat events, applicable to both self-poisonings and concern for malicious poisonings. Poison centers should be aware of this phenomenon, pay attention to local media and plan accordingly if a poisoning event receives significant media coverage. The media should be more sensitive to the content of their coverage and avoid providing "how to" poisoning information.
Steinmetz, Melissa; Czupryna, Anna; Bigambo, Machunde; Mzimbiri, Imam; Powell, George; Gwakisa, Paul
2015-01-01
In this study we show that incentives (dog collars and owner wristbands) are effective at increasing owner participation in mass dog rabies vaccination clinics and we conclude that household questionnaire surveys and the mark-re-sight (transect survey) method for estimating post-vaccination coverage are accurate when all dogs, including puppies, are included. Incentives were distributed during central-point rabies vaccination clinics in northern Tanzania to quantify their effect on owner participation. In villages where incentives were handed out participation increased, with an average of 34 more dogs being vaccinated. Through economies of scale, this represents a reduction in the cost-per-dog of $0.47. This represents the price-threshold under which the cost of the incentive used must fall to be economically viable. Additionally, vaccination coverage levels were determined in ten villages through the gold-standard village-wide census technique, as well as through two cheaper and quicker methods (randomized household questionnaire and the transect survey). Cost data were also collected. Both non-gold standard methods were found to be accurate when puppies were included in the calculations, although the transect survey and the household questionnaire survey over- and under-estimated the coverage respectively. Given that additional demographic data can be collected through the household questionnaire survey, and that its estimate of coverage is more conservative, we recommend this method. Despite the use of incentives the average vaccination coverage was below the 70% threshold for eliminating rabies. We discuss the reasons and suggest solutions to improve coverage. Given recent international targets to eliminate rabies, this study provides valuable and timely data to help improve mass dog vaccination programs in Africa and elsewhere. PMID:26633821
Breban, Romulus
2011-01-01
Both pandemic and seasonal influenza are receiving more attention from mass media than ever before. Topics such as epidemic severity and vaccination are changing the way in which we perceive the utility of disease prevention. Voluntary influenza vaccination has been recently modeled using inductive reasoning games. It has thus been found that severe epidemics may occur because individuals do not vaccinate and, instead, attempt to benefit from the immunity of their peers. Such epidemics could be prevented by voluntary vaccination if incentives were offered. However, a key assumption has been that individuals make vaccination decisions based on whether there was an epidemic each influenza season; no other epidemiological information is available to them. In this work, we relax this assumption and investigate the consequences of making more informed vaccination decisions while no incentives are offered. We obtain three major results. First, individuals will not cooperate enough to constantly prevent influenza epidemics through voluntary vaccination no matter how much they learned about influenza epidemiology. Second, broadcasting epidemiological information richer than whether an epidemic occurred may stabilize the vaccination coverage and suppress severe influenza epidemics. Third, the stable vaccination coverage follows the trend of the perceived benefit of vaccination. However, increasing the amount of epidemiological information released to the public may either increase or decrease the perceived benefit of vaccination. We discuss three scenarios where individuals know, in addition to whether there was an epidemic, (i) the incidence, (ii) the vaccination coverage and (iii) both the incidence and the vaccination coverage, every influenza season. We show that broadcasting both the incidence and the vaccination coverage could yield either better or worse vaccination coverage than broadcasting each piece of information on its own.
Health Newscasts for Increasing Influenza Vaccination Coverage: An Inductive Reasoning Game Approach
Breban, Romulus
2011-01-01
Both pandemic and seasonal influenza are receiving more attention from mass media than ever before. Topics such as epidemic severity and vaccination are changing the way in which we perceive the utility of disease prevention. Voluntary influenza vaccination has been recently modeled using inductive reasoning games. It has thus been found that severe epidemics may occur because individuals do not vaccinate and, instead, attempt to benefit from the immunity of their peers. Such epidemics could be prevented by voluntary vaccination if incentives were offered. However, a key assumption has been that individuals make vaccination decisions based on whether there was an epidemic each influenza season; no other epidemiological information is available to them. In this work, we relax this assumption and investigate the consequences of making more informed vaccination decisions while no incentives are offered. We obtain three major results. First, individuals will not cooperate enough to constantly prevent influenza epidemics through voluntary vaccination no matter how much they learned about influenza epidemiology. Second, broadcasting epidemiological information richer than whether an epidemic occurred may stabilize the vaccination coverage and suppress severe influenza epidemics. Third, the stable vaccination coverage follows the trend of the perceived benefit of vaccination. However, increasing the amount of epidemiological information released to the public may either increase or decrease the perceived benefit of vaccination. We discuss three scenarios where individuals know, in addition to whether there was an epidemic, (i) the incidence, (ii) the vaccination coverage and (iii) both the incidence and the vaccination coverage, every influenza season. We show that broadcasting both the incidence and the vaccination coverage could yield either better or worse vaccination coverage than broadcasting each piece of information on its own. PMID:22205944
Campos, Nicole G.; Castle, Philip E.; Wright, Thomas C.; Kim, Jane J.
2016-01-01
As cervical cancer screening programs are implemented in low-resource settings, protocols are needed to maximize health benefits under operational constraints. Our objective was to develop a framework for examining health and economic tradeoffs between screening test sensitivity, population coverage, and follow-up of screen-positive women, to help decision makers identify where program investments yield the greatest value. As an illustrative example, we used an individual-based Monte Carlo simulation model of the natural history of human papillomavirus (HPV) and cervical cancer calibrated to epidemiologic data from Uganda. We assumed once in a lifetime screening at age 35 with two-visit HPV DNA testing or one-visit visual inspection with acetic acid (VIA). We assessed the health and economic tradeoffs that arise between 1) test sensitivity and screening coverage; 2) test sensitivity and loss to follow-up (LTFU) of screen-positive women; and 3) test sensitivity, screening coverage, and LTFU simultaneously. The decline in health benefits associated with sacrificing HPV DNA test sensitivity by 20% (e.g., shifting from provider- to self-collection of specimens) could be offset by gains in coverage if coverage increased by at least 20%. When LTFU was 10%, two-visit HPV DNA testing with 80-90% sensitivity was more effective and more cost-effective than one-visit VIA with 40% sensitivity, and yielded greater health benefits than VIA even as VIA sensitivity increased to 60% and HPV test sensitivity declined to 70%. As LTFU increased, two-visit HPV DNA testing became more costly and less effective than one-visit VIA. Setting-specific data on achievable test sensitivity, coverage, follow-up rates, and programmatic costs are needed to guide programmatic decision making for cervical cancer screening. PMID:25943074
NASA Astrophysics Data System (ADS)
Li, Xuechun; Li, Dian; Wang, Younian
2016-09-01
A dielectric barrier discharge (DBD) can generate a low-temperature plasma easily at atmospheric pressure and has been investigated for applications in trials in cancer therapy, sterilization, air pollution control, etc. It has been confirmed that reactive oxygen species (ROS) play a key role in the processes. In this work, we use a fluid model to simulate the plasma characteristics for DBD in argon-oxygen mixture. The effects of oxygen concentration on the plasma characteristics have been discussed. The evolution mechanism of ROS has been systematically analyzed. It was found that the ground state oxygen atoms and oxygen molecular ions are the dominated oxygen species under the considered oxygen concentrations. With the oxygen concentration increasing, the densities of electrons, argon atomic ions, resonance state argon atoms, metastable state argon atoms and excited state argon atoms all show a trend of decline. The oxygen molecular ions density is high and little influenced by the oxygen concentration. Ground state oxygen atoms density tends to increase before falling. The ozone density increases significantly. Increasing the oxygen concentration, the discharge mode begins to change gradually from the glow discharge mode to Townsend discharge mode. Project supported by the National Natural Science Foundation of China (Grant No. 11175034).
Balancing Evidence and Uncertainty when Considering Rubella Vaccine Introduction
Lessler, Justin; Metcalf, C. Jessica E.
2013-01-01
Background Despite a safe and effective vaccine, rubella vaccination programs with inadequate coverage can raise the average age of rubella infection; thereby increasing rubella cases among pregnant women and the resulting congenital rubella syndrome (CRS) in their newborns. The vaccination coverage necessary to reduce CRS depends on the birthrate in a country and the reproductive number, R0, a measure of how efficiently a disease transmits. While the birthrate within a country can be known with some accuracy, R0 varies between settings and can be difficult to measure. Here we aim to provide guidance on the safe introduction of rubella vaccine into countries in the face of substantial uncertainty in R0. Methods We estimated the distribution of R0 in African countries based on the age distribution of rubella infection using Bayesian hierarchical models. We developed an age specific model of rubella transmission to predict the level of R0 that would result in an increase in CRS burden for specific birth rates and coverage levels. Combining these results, we summarize the safety of introducing rubella vaccine across demographic and coverage contexts. Findings The median R0 of rubella in the African region is 5.2, with 90% of countries expected to have an R0 between 4.0 and 6.7. Overall, we predict that countries maintaining routine vaccination coverage of 80% or higher are can be confident in seeing a reduction in CRS over a 30 year time horizon. Conclusions Under realistic assumptions about human contact, our results suggest that even in low birth rate settings high vaccine coverage must be maintained to avoid an increase in CRS. These results lend further support to the WHO recommendation that countries reach 80% coverage for measles vaccine before introducing rubella vaccination, and highlight the importance of maintaining high levels of vaccination coverage once the vaccine is introduced. PMID:23861777
Balancing evidence and uncertainty when considering rubella vaccine introduction.
Lessler, Justin; Metcalf, C Jessica E
2013-01-01
Despite a safe and effective vaccine, rubella vaccination programs with inadequate coverage can raise the average age of rubella infection; thereby increasing rubella cases among pregnant women and the resulting congenital rubella syndrome (CRS) in their newborns. The vaccination coverage necessary to reduce CRS depends on the birthrate in a country and the reproductive number, R0, a measure of how efficiently a disease transmits. While the birthrate within a country can be known with some accuracy, R0 varies between settings and can be difficult to measure. Here we aim to provide guidance on the safe introduction of rubella vaccine into countries in the face of substantial uncertainty in R0. We estimated the distribution of R0 in African countries based on the age distribution of rubella infection using Bayesian hierarchical models. We developed an age specific model of rubella transmission to predict the level of R0 that would result in an increase in CRS burden for specific birth rates and coverage levels. Combining these results, we summarize the safety of introducing rubella vaccine across demographic and coverage contexts. The median R0 of rubella in the African region is 5.2, with 90% of countries expected to have an R0 between 4.0 and 6.7. Overall, we predict that countries maintaining routine vaccination coverage of 80% or higher are can be confident in seeing a reduction in CRS over a 30 year time horizon. Under realistic assumptions about human contact, our results suggest that even in low birth rate settings high vaccine coverage must be maintained to avoid an increase in CRS. These results lend further support to the WHO recommendation that countries reach 80% coverage for measles vaccine before introducing rubella vaccination, and highlight the importance of maintaining high levels of vaccination coverage once the vaccine is introduced.
Omura, J; Yano, H; Tryk, D A; Watanabe, M; Uchida, H
2014-01-14
To gain deeper insight into the role of adsorbed oxygenated species in the O2 reduction reaction (ORR) kinetics on platinum and platinum-cobalt alloys for fuel cells, we carried out a series of measurements with the electrochemical quartz crystal microbalance (EQCM) and the rotating disk electrode (RDE) in acid solution. The effects of anion adsorption on the activities for the ORR were first assessed in HClO4 and HF electrolyte solutions at various concentrations. In our previous work (Part 1), we reported that the perchlorate anion adsorbs specifically on bulk-Pt, with a Frumkin-Temkin isotherm, that is, a linear relationship between Δm and log[HClO4]. Here, we find that the specific adsorption on the Pt-skin/Pt3Co alloy was significantly stronger than that on bulk-Pt, in line with its modified electronic properties. The kinetically controlled current density j(k) for the O2 reduction at the Pt-skin/Pt3Co-RDE was about 9 times larger than that of the bulk-Pt-RDE in 0.01 M HClO4 saturated with air, but the j(k) values on Pt-skin/Pt3Co decreased with increasing [HClO4] more steeply than in the case of Pt, due to the blocking of the active sites by the specifically adsorbed ClO4(-). We have detected reversible mass changes for one or more adsorbed oxygen-containing species (Ox = O2, O, OH, H2O) on the Pt-skin/Pt3Co-EQCM and Pt-EQCM in O2-saturated and He-purged 0.01 M HClO4 solutions, in which the specific adsorption of ClO4(-) anions was negligible. The coverages of oxygen species θ(Ox) on the Pt-skin/Pt3Co in the potential range from 0.86 to 0.96 V in the O2-saturated solution were found to be larger than those on pure Pt, providing strong evidence that the higher O2 reduction activity on the Pt3Co is correlated with higher θ(Ox), contrary to the conventional view.
Cutting back but not cutting out: small employers respond to premium increases.
Short, Ashley C; Lesser, Cara S
2002-10-01
Rising premiums and a weak economy are generating questions about the potential erosion of health insurance coverage, particularly for the more than 46 million Americans who work for small firms. People working in small firms typically have less access to coverage than those in large firms. In 2000 and early 2001, the Center for Studying Health System Change (HSC) conducted its third round of site visits to 12 nationally representative metropolitan areas and found that while few small employers actually dropped coverage, many increased the employee share of premiums, raised copayments and deductibles, switched products and carriers and/or reduced benefits. With the U.S. economy now in rougher shape, small employers may pare back coverage even more, putting affordable health care further out of the reach of workers and their families.
Expanding proteome coverage with orthogonal-specificity α-Lytic proteases
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meyer, Jesse G.; Kim, Sangtae; Maltby, David A.
2014-03-01
Bottom-up proteomics studies traditionally involve proteome digestion with a single protease, trypsin. However, trypsin alone does not generate peptides that encompass the entire proteome. Alternative proteases have been explored, but most have specificity for charged amino acid side chains. Therefore, additional proteases that improve proteome coverage by cleavage at sequences complimentary to trypsin may increase proteome coverage. We demonstrate the novel application of two proteases for bottom-up proteomics: wild type alpha-lytic protease (WaLP), and an active site mutant of WaLP, M190A alpha-lytic protease (MaLP). We assess several relevant factors including MS/MS fragmentation, peptide length, peptide yield, and protease specificity. Bymore » combining data from separate digestions with trypsin, LysC, WaLP, and MaLP, proteome coverage was increased 101% compared to trypsin digestion alone. To demonstrate how the gained sequence coverage can access additional PTM information, we show identification of a number of novel phosphorylation sites in the S. pombe proteome and include an illustrative example from the protein MPD2, wherein two novel sites are identified, one in a tryptic peptide too short to identify and the other in a sequence devoid of tryptic sites. The specificity of WaLP and MaLP for aliphatic amino acid side chains was particularly valuable for coverage of membrane protein sequences, which increased 350% when the data from trypsin, LysC, WaLP, and MaLP were combined.« less
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 8 2014-10-01 2014-10-01 false Endorsement of surety bond increasing or decreasing amount of coverage, Form MA-311. 308.531 Section 308.531 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Open Policy War Risk Cargo...
Dix, Laura Marie Louise; Weeke, Lauren Carleen; de Vries, Linda Simone; Groenendaal, Floris; Baerts, Willem; van Bel, Frank; Lemmers, Petra Maria Anna
2017-08-01
To evaluate the effects of acute arterial carbon dioxide partial pressure changes on cerebral oxygenation and electrical activity in infants born preterm. This retrospective observational study included ventilated infants born preterm with acute fluctuations of continuous end-tidal CO 2 (etCO 2 ) as a surrogate marker for arterial carbon dioxide partial pressure, during the first 72 hours of life. Regional cerebral oxygen saturation and fractional tissue oxygen extraction were monitored with near-infrared spectroscopy. Brain activity was monitored with 2-channel electroencephalography. Spontaneous activity transients (SATs) rate (SATs/minute) and interval between SATs (in seconds) were calculated. Ten-minute periods were selected for analysis: before, during, and after etCO 2 fluctuations of ≥5 mm Hg. Thirty-eight patients (mean ± SD gestational age of 29 ± 1.8 weeks) were included, with 60 episodes of etCO 2 increase and 70 episodes of etCO 2 decrease. During etCO 2 increases, brain oxygenation increased (regional cerebral oxygen saturation increased, fractional tissue oxygen extraction decreased; P < .01) and electrical activity decreased (SATs/minute decreased, interval between SATs increased; P < .01). All measures recovered when etCO 2 returned to baseline. During etCO 2 decreases, brain oxygenation decreased (regional cerebral oxygen saturation decreased, fractional tissue oxygen extraction decreased; P < .01) and brain activity increased (SATs/minute increased, P < .05), also with recovery after return of etCO 2 to baseline. An acute increase in etCO 2 is associated with increased cerebral oxygenation and decreased brain activity, whereas an acute decrease is associated with decreased cerebral oxygenation and slightly increased brain activity. Combining continuous CO 2 monitoring with near-infrared spectroscopy may enable the detection of otherwise undetected fluctuations in arterial carbon dioxide partial pressure that may be harmful to the neonatal brain. Copyright © 2017 Elsevier Inc. All rights reserved.
Macroeconomic Analysis of Universal Coverage in the U.S.
NASA Astrophysics Data System (ADS)
Feng, Zhigang
In this paper I employ a dynamic general equilibrium model to study macroeconomic effects and welfare implications of health policies for universal coverage in the U.S. The model is calibrated to the U.S. data. Numerical simulations indicate that adopting universal coverage has several important macroeconomic effects on health expenditures, hours worked, and increases welfare by improving aggregate health status, and removing adverse selection.
Seo, Jeongmin; Lim, Juwon
2018-05-05
Influenza is a major cause of morbidity and mortality worldwide. Annual vaccination is effective in its prevention and is recommended especially in susceptible populations such as the elderly over 65 years, children younger than 5, pregnant women, and people with chronic diseases. Overall, South Korea has a high vaccination rate owing to its National Immunization Program, although the method and extent of its coverage varies among the target subgroups. The aim of this study is to assess the trend of influenza vaccination coverage between 2005 and 2014 in South Korea to address the influence of sociodemographic and disease factors on vaccination behavior. Also, we aim to compare the vaccination coverage of target subgroups and evaluate the effect of relevant policies to provide suggestions for their improvement. A total of 61,036 respondents from the Korea National Health and Nutrition Examination Surveys III to VI were included. The total influenza vaccination coverage increased from 38.0% in 2005 to 44.1% in 2014. Vaccination coverage was higher among the elderly aged ≥65 years (range, 70.0-79.8%; p-for-trend <0.001) and children under 5 (range, 64.6-78.9%; p-for-trend < 0.001) than among pregnant women (range, 9.4-37.8%; p-for-trend = 0.122) and people with chronic diseases (range, 29.6-42.6%; p-for-trend = 0.068) from 2005 to 2014. High vaccination coverage was associated with female gender, rural residence, low education level, high income, and increasing number of chronic diseases. But the effect of high income on high vaccination coverage was absent in the elderly aged ≥65 years and children under 5. Influenza vaccination rates have steadily increased from 2005 to 2014 in South Korea. Disparities between target groups correspond to their financial coverage under the National Immunization Program, and financial aids remove the influence of high income on higher vaccination rates. Future vaccination policies should focus on pregnant women and people with chronic diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.
Woodyard, James G; Greenwell, Henry; Hill, Margaret; Drisko, Connie; Iasella, John M; Scheetz, James
2004-01-01
The primary aim of this randomized, controlled, blinded, clinical investigation was to compare the coronally positioned flap (CPF) plus an acellular dermal matrix (ADM) allograft to CPF alone to determine their effect on gingival thickness and percent root coverage. Twenty-four subjects with one Miller Class I or II buccal recession defect of > or = 3 mm were treated with a CPF plus ADM or a CPF alone. Multiple additional recession sites were treated with the same flap procedure, and all sites were studied for 6 months. Tissue thickness was measured at the sulcus base and at the mucogingival junction of all teeth, with an SDM ultrasonic gingival thickness meter. For the ADM sites, mean initial recession of 3.46 mm was reduced to 0.04 mm for defect coverage of 3.42 mm or 99% (P < 0.05). For the CPF group, mean initial recession of 3.27 mm was reduced to 1.08 mm for defect coverage of 2.19 mm or 67% (P < 0.05). The difference between ADM and CPF groups was statistically significant (P < 0.05). Marginal soft-tissue thickness was increased by 0.40 mm (P < 0.05) for the ADM group, whereas the CPF group remained essentially unchanged. Keratinized tissue was increased for the ADM group by 0.81 mm (P < 0.05), whereas the CPF group increased by 0.33 mm (P > 0.05). No additional root coverage was gained due to creeping attachment between 2 and 6 months for either group. Treatment with a CPF plus an ADM allograft significantly increased gingival thickness when compared with a CPF alone. Recession defect coverage was significantly improved with the use of ADM.
Fronstin, Paul
2007-10-01
This Issue Brief provides historic data through 2006 on the number and percentage of nonelderly individuals with and without health insurance. Based on EBRI estimates from the U.S. Census Bureau's March 2007 Current Population Survey (CPS), it reflects 2006 data. It also discusses trends in coverage for the 1994-2006 period and highlights characteristics that typically indicate whether an individual is insured. HEALTH COVERAGE CONTINUES DECLINE: The percentage of the nonelderly population (under age 65) with health insurance coverage continued to decline, reaching to a post-1994 low of 82.1 percent in 2006. Declines in health insurance coverage have been recorded in all but four years since 1994, when 36.5 million nonelderly individuals were uninsured; in 2006, the uninsured population was 46.5 million. EMPLOYMENT-BASED COVERAGE REMAINS DOMINANT SOURCE OF HEALTH COVERAGE: Employment-based health benefits remain by far the most common form of health coverage in the United States, consistently covering 60-70 percent of nonelderly individuals. In 2006, 62.2 percent of the nonelderly population had employment-based health benefits, as compared with 64.4 percent in 1994. Between 1994 and 2000, the percentage of the nonelderly population with employment-based coverage expanded. Since 2000, the percentage has declined. PUBLIC PROGRAM COVERAGE IS STABLE: Public-sector health coverage was slightly lower as a percentage of the population in 2006, accounting for 17.5 percent of the nonelderly population. The decline was due to a drop in the percentage of the population covered by the Tricare/CHAMPVA program. Enrollment in Medicaid and the State Children's Health Insurance Program increased, reaching 34.9 million in 2006, and covering 13.4 percent of the nonelderly population, which is significantly above the 10.5 percent level of 1999, but not far above the 12.7 percent level of 1994. INDIVIDUAL COVERAGE STABLE: Individually purchased health coverage was unchanged in 2006 and has basically hovered in the high 6 and low 7 percent range since 1994. PRIVATE- VS. PUBLIC-COVERAGE TRENDS REVERSING: Health insurance coverage generally has not sustained unbroken trends since 1994. There were crosscurrents: Employment-based coverage expanded significantly in the 1994-2000 period to exceed the growth in public programs. Subsequently, the dynamic reversed, as public programs expanded while employment-based coverage declined. It appears that 2005 might be the beginning of a new trend, where the erosion in employment-based coverage is not being offset by expansions in public programs. This may be due to the fact that, while unemployment is relatively low, the cost of providing health benefits continues to increase faster than inflation.
Kakiuchi, Kenta; Matsuda, Kenichi; Harii, Norikazu; Sou, Keitaro; Aoki, Junko; Takeoka, Shinji
2015-09-01
Micro/nano-bubbles are practical nanomaterials designed to increase the gas content in liquids. We attempted to use oxygen micro/nano-bubble dispersions as an oxygen-rich liquid as a means for total liquid ventilation. To determine the oxygen content in the bubble dispersion, a new method based on a spectrophotometric change between oxy- and deoxy-hemoglobin was established. The oxygen micro/nano-bubble dispersion was supplied to an experimental total ventilation liquid in anesthetic rats. Though the amount of dissolving oxygen was as low as 6 mg/L in physiological saline, the oxygen content in the oxygen micro/nano-bubble dispersion was increased to 45 mg/L. The positive correlation between the oxygen content and the life-saving time under liquid ventilation clearly indicates that the life-saving time is prolonged by increasing the oxygen content in the oxygen micro/nano-bubble dispersion. This is the first report indicating that the oxygen micro/nano-bubbles containing a sufficient amount of oxygen are useful in producing oxygen-rich liquid for the process of liquid ventilation.
Locations of Sampling Stations for Water Quality Monitoring in Water Distribution Networks.
Rathi, Shweta; Gupta, Rajesh
2014-04-01
Water quality is required to be monitored in the water distribution networks (WDNs) at salient locations to assure the safe quality of water supplied to the consumers. Such monitoring stations (MSs) provide warning against any accidental contaminations. Various objectives like demand coverage, time for detection, volume of water contaminated before detection, extent of contamination, expected population affected prior to detection, detection likelihood and others, have been independently or jointly considered in determining optimal number and location of MSs in WDNs. "Demand coverage" defined as the percentage of network demand monitored by a particular monitoring station is a simple measure to locate MSs. Several methods based on formulation of coverage matrix using pre-specified coverage criteria and optimization have been suggested. Coverage criteria is defined as some minimum percentage of total flow received at the monitoring stations that passed through any upstream node included then as covered node of the monitoring station. Number of monitoring stations increases with the increase in the value of coverage criteria. Thus, the design of monitoring station becomes subjective. A simple methodology is proposed herein which priority wise iteratively selects MSs to achieve targeted demand coverage. The proposed methodology provided the same number and location of MSs for illustrative network as an optimization method did. Further, the proposed method is simple and avoids subjectivity that could arise from the consideration of coverage criteria. The application of methodology is also shown on a WDN of Dharampeth zone (Nagpur city WDN in Maharashtra, India) having 285 nodes and 367 pipes.
Mbogo, Barnabas Africanus; McGill, Deborah
2016-08-19
Globally, about 150 million people experience catastrophic healthcare expenditure services annually. Among low and middle income countries, out-of-pocket expenditure pushes about 100 million people into poverty annually. In Botswana, 83 % of the general population and 58 % of employed individuals do not have medical aid coverage. Moreover, inequity allocation of financial resources between health services suggests marginalization of population-based health care services (i.e. diseases prevention and health promotion). The purpose of the study is to explore perspectives on employed individuals regarding financing population based health care interventions towards Universal Health Coverage (UHC) in order to make recommendations to the Ministry of Health on health financing options to cover population-based health services. A qualitative design grounded in interpretivist epistemology through social constructivism lens was critical for exploring perspectives of employed individuals. Through purposive and snowballing sampling techniques, a total of 15 respondents including 8 males and 7 females were recruited and interviewed using a semi-structured format. Their age ranged from 23 to 59 years with a median of 36 years. Data was analyzed using Thematic Content Analysis technique. Use of social constructivism lens enabled to classify emerging themes into population coverage, health services coverage and financial protection issues. Despite broad understanding of health coverage schemes among participants, knowledge appears insignificant in increasing enrolment. Participants indicated limited understanding of UHC concepts, however showed willingness to embrace UHC upon brief description. Main thematic issues raised include: exclusion of population-based health services from coverage scheme; disparity in financial protection and health services coverage among enrollees; inability to sustain contracted employees; and systematic exclusion of unemployed individuals and informal sector employees. Increasing enrolment in health coverage schemes requires targeted campaign for information dissemination through use of myriads mass media including: social networks, TV, Radio and others. Moreover, re-designing health insurance schemes is critical in order to include population-based interventions; expand uptake of unemployed and informal sector employees; flexibility in monthly premiums payment plan and use of technology to increase access to payment points. Further study need to evaluate the content of health financing policy in Botswana measured against the World Health Organization Universal Health Coverage conceptual requirements for Low and Middle Income Countries.
Epidemiological game-theory dynamics of chickenpox vaccination in the USA and Israel
Liu, Jingzhou; Kochin, Beth F.; Tekle, Yonas I.; Galvani, Alison P.
2012-01-01
The general consensus from epidemiological game-theory studies is that vaccination coverage driven by self-interest (Nash vaccination) is generally lower than group-optimal coverage (utilitarian vaccination). However, diseases that become more severe with age, such as chickenpox, pose an exception to this general consensus. An individual choice to be vaccinated against chickenpox has the potential to harm those not vaccinated by increasing the average age at infection and thus the severity of infection as well as those already vaccinated by increasing the probability of breakthrough infection. To investigate the effects of these externalities on the relationship between Nash and utilitarian vaccination coverages for chickenpox, we developed a game-theory epidemic model that we apply to the USA and Israel, which has different vaccination programmes, vaccination and treatment costs, as well as vaccination coverage levels. We find that the increase in chickenpox severity with age can reverse the typical relationship between utilitarian and Nash vaccination coverages in both the USA and Israel. Our model suggests that to obtain herd immunity of chickenpox vaccination, subsidies or external regulation should be used if vaccination costs are high. By contrast, for low vaccination costs, improving awareness of the vaccine and the potential cost of chickenpox infection is crucial. PMID:21632611
Epidemiological game-theory dynamics of chickenpox vaccination in the USA and Israel.
Liu, Jingzhou; Kochin, Beth F; Tekle, Yonas I; Galvani, Alison P
2012-01-07
The general consensus from epidemiological game-theory studies is that vaccination coverage driven by self-interest (Nash vaccination) is generally lower than group-optimal coverage (utilitarian vaccination). However, diseases that become more severe with age, such as chickenpox, pose an exception to this general consensus. An individual choice to be vaccinated against chickenpox has the potential to harm those not vaccinated by increasing the average age at infection and thus the severity of infection as well as those already vaccinated by increasing the probability of breakthrough infection. To investigate the effects of these externalities on the relationship between Nash and utilitarian vaccination coverages for chickenpox, we developed a game-theory epidemic model that we apply to the USA and Israel, which has different vaccination programmes, vaccination and treatment costs, as well as vaccination coverage levels. We find that the increase in chickenpox severity with age can reverse the typical relationship between utilitarian and Nash vaccination coverages in both the USA and Israel. Our model suggests that to obtain herd immunity of chickenpox vaccination, subsidies or external regulation should be used if vaccination costs are high. By contrast, for low vaccination costs, improving awareness of the vaccine and the potential cost of chickenpox infection is crucial.
Zack, Matthew M.; Strine, Tara W.; Druss, Benjamin G.; Simoes, Eduardo
2013-01-01
Objectives. We examined the impact of Massachusetts health reform and its public health component (enacted in 2006) on change in health insurance coverage by perceived health. Methods. We used 2003–2009 Behavioral Risk Factor Surveillance System data. We used a difference-in-differences framework to examine the experience in Massachusetts to predict the outcomes of national health care reform. Results. The proportion of adults aged 18 to 64 years with health insurance coverage increased more in Massachusetts than in other New England states (4.5%; 95% confidence interval [CI] = 3.5%, 5.6%). For those with higher perceived health care need (more recent mentally and physically unhealthy days and activity limitation days [ALDs]), the postreform proportion significantly exceeded prereform (P < .001). Groups with higher perceived health care need represented a disproportionate increase in health insurance coverage in Massachusetts compared with other New England states—from 4.3% (95% CI = 3.3%, 5.4%) for fewer than 14 ALDs to 9.0% (95% CI = 4.5%, 13.5%) for 14 or more ALDs. Conclusions. On the basis of the Massachusetts experience, full implementation of the Affordable Care Act may increase health insurance coverage especially among populations with higher perceived health care need. PMID:23597359
Gilardi, Francesco; Castelli Gattinara, Guido; Vinci, Maria Rosaria; Ciofi Degli Atti, Marta; Santilli, Veronica; Brugaletta, Rita; Santoro, Annapaola; Montanaro, Rosina; Lavorato, Luisa; Raponi, Massimiliano; Zaffina, Salvatore
2018-04-24
Despite relevant recommendations and evidences on the efficacy of influenza vaccination in health care workers (HCWs), vaccination coverage rates in Europe and Italy currently do not exceed 25%. Aim of the study is to measure the variations in vaccination coverage rates in an Italian pediatric hospital after a promotion campaign performed in the period October⁻December 2017. The design is a pre-post intervention study. The intervention is based on a wide communication campaign and an expanded offer of easy vaccination on site. The study was carried out at Bambino Gesù Children’s hospital in Rome, Italy, on the whole population of HCWs. Univariate and multivariate statistical analyses were performed. Vaccination coverage rate increased in 2017/18 campaign compared with the 2016/17 one (+95 HCWs vaccinated; +4.4%). The highest increases were detected in males (+45.7%), youngest employees (+142.9%), mean age of employment (+175%), other HCWs (+209.1%), Emergency Area (+151.6%) and Imaging Diagnostic Department (+200.0%). At multivariate logistic regression, working in some departments and being nurses represents a higher risk of being unvaccinated. Although the vaccination coverage rate remained low, a continuous increase of the coverage rate and development of a different consciousness in HCWs was highlighted. The study significantly identified the target for future campaigns.
"Aging Out" of Dependent Coverage and the Effects on US Labor Market and Health Insurance Choices.
Dahlen, Heather M
2015-11-01
I examined how labor market and health insurance outcomes were affected by the loss of dependent coverage eligibility under the Patient Protection and Affordable Care Act (ACA). I used National Health Interview Survey (NHIS) data and regression discontinuity models to measure the percentage-point change in labor market and health insurance outcomes at age 26 years. My sample was restricted to unmarried individuals aged 24 to 28 years and to a period of time before the ACA's individual mandate (2011-2013). I ran models separately for men and women to determine if there were differences based on gender. Aging out of this provision increased employment among men, employer-sponsored health insurance offers for women, and reports that health insurance coverage was worse than it was 1 year previously (overall and for young women). Uninsured rates did not increase at age 26 years, but there was an increase in the purchase of non-group health coverage, indicating interest in remaining insured after age 26 years. Many young adults will turn to state and federal health insurance marketplaces for information about health coverage. Because young adults (aged 18-29 years) regularly use social media sites, these sites could be used to advertise insurance to individuals reaching their 26th birthdays.
Examining levels, distribution and correlates of health insurance coverage in Kenya.
Kazungu, Jacob S; Barasa, Edwine W
2017-09-01
To examine the levels, inequalities and factors associated with health insurance coverage in Kenya. We analysed secondary data from the Kenya Demographic and Health Survey (KDHS) conducted in 2009 and 2014. We examined the level of health insurance coverage overall, and by type, using an asset index to categorise households into five socio-economic quintiles with quintile 5 (Q5) being the richest and quintile 1 (Q1) being the poorest. The high-low ratio (Q5/Q1 ratio), concentration curve and concentration index (CIX) were employed to assess inequalities in health insurance coverage, and logistic regression to examine correlates of health insurance coverage. Overall health insurance coverage increased from 8.17% to 19.59% between 2009 and 2014. There was high inequality in overall health insurance coverage, even though this inequality decreased between 2009 (Q5/Q1 ratio of 31.21, CIX = 0.61, 95% CI 0.52-0.0.71) and 2014 (Q5/Q1 ratio 12.34, CIX = 0.49, 95% CI 0.45-0.52). Individuals that were older, employed in the formal sector; married, exposed to media; and male, belonged to a small household, had a chronic disease and belonged to rich households, had increased odds of health insurance coverage. Health insurance coverage in Kenya remains low and is characterised by significant inequality. In a context where over 80% of the population is in the informal sector, and close to 50% live below the national poverty line, achieving high and equitable coverage levels with contributory and voluntary health insurance mechanism is problematic. Kenya should consider a universal, tax-funded mechanism that ensures revenues are equitably and efficiently collected, and everyone (including the poor and those in the informal sector) is covered. © 2017 The Authors. Tropical Medicine & International Health published by John Wiley & Sons Ltd.
Supra-plasma expanders: the future of treating blood loss and anemia without red cell transfusions?
Tsai, Amy G; Vázquez, Beatriz Y Salazar; Hofmann, Axel; Acharya, Seetharama A; Intaglietta, Marcos
2015-01-01
Oxygen delivery capacity during profoundly anemic conditions depends on blood's oxygen-carrying capacity and cardiac output. Oxygen-carrying blood substitutes and blood transfusion augment oxygen-carrying capacity, but both have given rise to safety concerns, and their efficacy remains unresolved. Anemia decreases oxygen-carrying capacity and blood viscosity. Present studies show that correcting the decrease of blood viscosity by increasing plasma viscosity with newly developed plasma expanders significantly improves tissue perfusion. These new plasma expanders promote tissue perfusion, increasing oxygen delivery capacity without increasing blood oxygen-carrying capacity, thus treating the effects of anemia while avoiding the transfusion of blood.
Noor, Abdisalan M; Amin, Abdinasir A; Akhwale, Willis S; Snow, Robert W
2007-01-01
Background Inexpensive and efficacious interventions that avert childhood deaths in sub-Saharan Africa have failed to reach effective coverage, especially among the poorest rural sectors. One particular example is insecticide-treated bed nets (ITNs). In this study, we present repeat observations of ITN coverage among rural Kenyan homesteads exposed at different times to a range of delivery models, and assess changes in coverage across socioeconomic groups. Methods and Findings We undertook a study of annual changes in ITN coverage among a cohort of 3,700 children aged 0–4 y in four districts of Kenya (Bondo, Greater Kisii, Kwale, and Makueni) annually between 2004 and 2006. Cross-sectional surveys of ITN coverage were undertaken coincidentally with the incremental availability of commercial sector nets (2004), the introduction of heavily subsidized nets through clinics (2005), and the introduction of free mass distributed ITNs (2006). The changing prevalence of ITN coverage was examined with special reference to the degree of equity in each delivery approach. ITN coverage was only 7.1% in 2004 when the predominant source of nets was the commercial retail sector. By the end of 2005, following the expansion of heavily subsidized clinic distribution system, ITN coverage rose to 23.5%. In 2006 a large-scale mass distribution of ITNs was mounted providing nets free of charge to children, resulting in a dramatic increase in ITN coverage to 67.3%. With each subsequent survey socioeconomic inequity in net coverage sequentially decreased: 2004 (most poor [2.9%] versus least poor [15.6%]; concentration index 0.281); 2005 (most poor [17.5%] versus least poor [37.9%]; concentration index 0.131), and 2006 with near-perfect equality (most poor [66.3%] versus least poor [66.6%]; concentration index 0.000). The free mass distribution method achieved highest coverage among the poorest children, the highly subsidised clinic nets programme was marginally in favour of the least poor, and the commercial social marketing favoured the least poor. Conclusions Rapid scaling up of ITN coverage among Africa's poorest rural children can be achieved through mass distribution campaigns. These efforts must form an important adjunct to regular, routine access to ITNs through clinics, and each complimentary approach should aim to make this intervention free to clients to ensure equitable access among those least able to afford even the cost of a heavily subsidized net. PMID:17713981
Tiede, L M; Cook, E A; Morsey, B; Fox, H S
2011-01-01
Mitochondrial dysfunction is implicated in a majority of neurodegenerative disorders and much study of neurodegenerative disease is done on cultured neurons. In traditional tissue culture, the oxygen level that cells experience is dramatically higher (21%) than in vivo conditions (1–11%). These differences can alter experimental results, especially, pertaining to mitochondria and oxidative metabolism. Our results show that primary neurons cultured at physiological oxygen levels found in the brain showed higher polarization, lower rates of ROS production, larger mitochondrial networks, greater cytoplasmic fractions of mitochondria and larger mitochondrial perimeters than those cultured at higher oxygen levels. Although neurons cultured in either physiological oxygen or atmospheric oxygen exhibit significant increases in mitochondrial reactive oxygen species (ROS) production when treated with the human immunodeficiency virus (HIV) virotoxin trans-activator of transcription, mitochondria of neurons cultured at physiological oxygen underwent depolarization with dramatically increased cell death, whereas those cultured at atmospheric oxygen became hyperpolarized with no increase in cell death. Studies with a second HIV virotoxin, negative regulation factor (Nef), revealed that Nef treatment also increased mitochondrial ROS production for both the oxygen conditions, but resulted in mitochondrial depolarization and increased death only in neurons cultured in physiological oxygen. These results indicate a role for oxidative metabolism in a mechanism of neurotoxicity during HIV infection and demonstrate the importance of choosing the correct, physiological, culture oxygen in mitochondrial studies performed in neurons. PMID:22190005
Wisk, Lauren E; Finkelstein, Jonathan A; Toomey, Sara L; Sawicki, Gregory S; Schuster, Mark A; Galbraith, Alison A
2018-06-01
To determine the effect of state-level dependent coverage expansion (DCE) with and without other state health reforms on exit from dependent coverage for adolescents and young adults (AYA). Administrative longitudinal data for 131,542 privately insured AYA in Massachusetts (DCE with other reforms) versus Maine and New Hampshire (DCE without other reforms) across three periods: prereform (1/00-12/06), poststate reform (1/07-9/10), and postfederal reform (10/10-12/12). A difference-in-differences estimator was used to determine the rate of exit from dependent coverage, age at exit from dependent coverage, and re-uptake of dependent coverage among AYA in states with comprehensive reforms versus DCE only. Implementation of DCE with other reforms was significantly associated with a 23 percent reduction in exit from dependent coverage among AYA compared to the reduction observed for DCE alone. Additionally, comprehensive reforms were associated with over two additional years of dependent coverage for the average AYA and a 33 percent increase in the odds of regaining dependent coverage after a prior loss. Findings suggest that an individual mandate and other reforms may enhance the effect of DCE in preventing loss of coverage among AYA. © Health Research and Educational Trust.
Song, In Gyu; Lee, Haewon; Yi, Jinseon; Kim, Min Sun; Park, Sang Min
2015-09-01
This study aimed to examine influenza vaccination coverage of North Korean defectors (NKD) in the Republic of Korea (Korea) and explore the factors affected the vaccination coverage. Total 378 NKD were analyzed. Four Korean control subjects were randomly matched by age and gender from the Korea National Health and Nutrition Examination Survey V (n = 1,500). The adjusted vaccination coverage revealed no statistical difference between the defectors group and indigenous group (29.1% vs. 29.5%, P = 0.915). In the aged under 50 group, the vaccination coverage of NKD was higher than that of Korean natives (37.8% vs. 25.8%, P = 0.016). However in the aged 50 yr and over group, the vaccination coverage of North Korean defectors was lower than that of the natives (28.0% vs. 37.6%, P = 0.189). Even the gap was wider in the aged 65 yr and over group (36.4% vs. 77.8%, P = 0.007). Gender and medical check-up experience within 2 yr showed association with the vaccination coverage of NKD. Influenza vaccination coverage of aged defectors' group (aged 50 yr and over) was lower than indigenous people though overall vaccination coverage was similar. Further efforts to increase influenza vaccination coverage of this group are needed.
Byrne, L; Ward, C; White, J M; Amirthalingam, G; Edelstein, M
2018-01-01
This study assessed variation in coverage of maternal pertussis vaccination, introduced in England in October 2012 in response to a national outbreak, and a new infant rotavirus vaccination programme, implemented in July 2013. Vaccine eligible patients were included from national vaccine coverage datasets and covered April 2014 to March 2015 for pertussis and January 2014 to June 2016 for rotavirus. Vaccine coverage (%) was calculated overall and by NHS England Local Team (LT), ethnicity and Index of Multiple Deprivation (IMD) quintile, and compared using binomial regression. Compared with white-British infants, the largest differences in rotavirus coverage were in 'other', white-Irish and black-Caribbean infants (-13·9%, -12·1% and -10·7%, respectively), after adjusting for IMD and LT. The largest differences in maternal pertussis coverage were in black-other and black-Caribbean women (-16·3% and -15·4%, respectively). Coverage was lowest in London LT for both programmes. Coverage decreased with increasing deprivation and was 14·0% lower in the most deprived quintile compared with the least deprived for the pertussis programme and 4·4% lower for rotavirus. Patients' ethnicity and deprivation were therefore predictors of coverage which contributed to, but did not wholly account for, geographical variation in coverage in England.
Irreversible adsorption of particles on heterogeneous surfaces.
Adamczyk, Zbigniew; Jaszczółt, Katarzyna; Michna, Aneta; Siwek, Barbara; Szyk-Warszyńska, Lilianna; Zembala, Maria
2005-12-30
Methods of theoretical and experimental evaluation of irreversible adsorption of particles, e.g., colloids and globular proteins at heterogeneous surfaces were reviewed. The theoretical models were based on the generalized random sequential adsorption (RSA) approach. Within the scope of these models, localized adsorption of particles occurring as a result of short-ranged attractive interactions with discrete adsorption sites was analyzed. Monte-Carlo type simulations performed according to this model enabled one to determine the initial flux, adsorption kinetics, jamming coverage and the structure of the particle monolayer as a function of the site coverage and the particle/site size ratio, denoted by lambda. It was revealed that the initial flux increased significantly with the site coverage theta(s) and the lambda parameter. This behavior was quantitatively interpreted in terms of the scaled particle theory. It also was demonstrated that particle adsorption kinetics and the jamming coverage increased significantly, at fixed site coverage, when the lambda parameter increased. Practically, for alpha = lambda2theta(s) > 1 the jamming coverage at the heterogeneous surfaces attained the value pertinent to continuous surfaces. The results obtained prove unequivocally that spherically shaped sites were more efficient in binding particles in comparison with disk-shaped sites. It also was predicted that for particle size ratio lambda < 4 the site multiplicity effect plays a dominant role, affecting significantly the structure of particle monolayers and the jamming coverage. Experimental results validating main aspects of these theoretical predictions also have been reviewed. These results were derived by using monodisperse latex particles adsorbing on substrates produced by covering uniform surface by adsorption sites of a desired size, coverage and surface charge. Particle deposition occurred under diffusion-controlled transport conditions and their coverage was evaluated by direct particle counting using the optical and electron microscopy. Adsorption kinetics was quantitatively interpreted in terms of numerical solutions of the governing diffusion equation with the non-linear boundary condition derived from Monte-Carlo simulations. It was proven that for site coverage as low as a few percent the initial flux at heterogeneous surfaces attained the maximum value pertinent to homogeneous surfaces. It also was demonstrated that the structure of larger particle monolayers, characterized in terms of the pair correlation function, showed much more short-range ordering than predicted for homogeneous surface monolayers at the same coverage. The last part of this review was devoted to detection of polyelectrolyte multilayers on various substrates via particle deposition experiments.
Salmaso, S.; Rota, M. C.; Ciofi Degli Atti, M. L.; Tozzi, A. E.; Kreidl, P.
1999-01-01
In 1998, a series of regional cluster surveys (the ICONA Study) was conducted simultaneously in 19 out of the 20 regions in Italy to estimate the mandatory immunization coverage of children aged 12-24 months with oral poliovirus (OPV), diphtheria-tetanus (DT) and viral hepatitis B (HBV) vaccines, as well as optional immunization coverage with pertussis, measles and Haemophilus influenzae b (Hib) vaccines. The study children were born in 1996 and selected from birth registries using the Expanded Programme of Immunization (EPI) cluster sampling technique. Interviews with parents were conducted to determine each child's immunization status and the reasons for any missed or delayed vaccinations. The study population comprised 4310 children aged 12-24 months. Coverage for both mandatory and optional vaccinations differed by region. The overall coverage for mandatory vaccines (OPV, DT and HBV) exceeded 94%, but only 79% had been vaccinated in accord with the recommended schedule (i.e. during the first year of life). Immunization coverage for pertussis increased from 40% (1993 survey) to 88%, but measles coverage (56%) remained inadequate for controlling the disease; Hib coverage was 20%. These results confirm that in Italy the coverage of only mandatory immunizations is satisfactory. Pertussis immunization coverage has improved dramatically since the introduction of acellular vaccines. A greater effort to educate parents and physicians is still needed to improve the coverage of optional vaccinations in all regions. PMID:10593033
Salmaso, S; Rota, M C; Ciofi Degli Atti, M L; Tozzi, A E; Kreidl, P
1999-01-01
In 1998, a series of regional cluster surveys (the ICONA Study) was conducted simultaneously in 19 out of the 20 regions in Italy to estimate the mandatory immunization coverage of children aged 12-24 months with oral poliovirus (OPV), diphtheria-tetanus (DT) and viral hepatitis B (HBV) vaccines, as well as optional immunization coverage with pertussis, measles and Haemophilus influenzae b (Hib) vaccines. The study children were born in 1996 and selected from birth registries using the Expanded Programme of Immunization (EPI) cluster sampling technique. Interviews with parents were conducted to determine each child's immunization status and the reasons for any missed or delayed vaccinations. The study population comprised 4310 children aged 12-24 months. Coverage for both mandatory and optional vaccinations differed by region. The overall coverage for mandatory vaccines (OPV, DT and HBV) exceeded 94%, but only 79% had been vaccinated in accord with the recommended schedule (i.e. during the first year of life). Immunization coverage for pertussis increased from 40% (1993 survey) to 88%, but measles coverage (56%) remained inadequate for controlling the disease; Hib coverage was 20%. These results confirm that in Italy the coverage of only mandatory immunizations is satisfactory. Pertussis immunization coverage has improved dramatically since the introduction of acellular vaccines. A greater effort to educate parents and physicians is still needed to improve the coverage of optional vaccinations in all regions.
Zu, Jian; Li, Miaolei; Zhuang, Guihua; Liang, Peifeng; Cui, Fuqiang; Wang, Fuzhen; Zheng, Hui; Liang, Xiaofeng
2018-04-01
The potential impact of increasing test-and-treat coverage on hepatitis B virus (HBV) infection remains unclear in China. The objective of this study was to develop a dynamic compartmental model at a population level to estimate the long-term effect of this strategy.Based on the natural history of HBV infection and 3 serosurvey data of hepatitis B in China, we proposed an age- and time-dependent discrete model to predict the number of new HBV infection, the number of chronic HBV infection, and the number of HBV-related deaths for the time from 2018 to 2050 under 5 different test-and-treat coverage and compared them with current intervention policy.Compared with current policy, if the test-and-treat coverage was increased to 100% since 2018, the numbers of chronic HBV infection, new HBV infection, and HBV-related deaths in 2035 would be reduced by 26.60%, 24.88%, 26.55%, respectively, and in 2050 it would be reduced by 44.93%, 43.29%, 43.67%, respectively. In contrast, if the test-and-treat coverage was increased by 10% every year since 2018, then the numbers of chronic HBV infection, new HBV infection, and HBV-related deaths in 2035 would be reduced by 21.81%, 20.10%, 21.40%, respectively, and in 2050 it would be reduced by 41.53%, 39.89%, 40.32%, respectively. In particular, if the test-and-treat coverage was increased to 75% since 2018, then the annual number of HBV-related deaths would begin to decrease from 2018. If the test-and-treat coverage was increased to above 25% since 2018, then the hepatitis B surface antigen (HBsAg) prevalence for population aged 1 to 59 years in China would be reduced to below 2% in 2035. Our model also showed that in 2035, the numbers of chronic HBV infection and HBV-related deaths in 65 to 69 age group would be reduced the most (about 1.6 million and 13 thousand, respectively).Increasing test-and-treat coverage would significantly reduce HBV infection in China, especially in the middle-aged people and older people. The earlier the treatment and the longer the time, the more significant the reduction. Implementation of test-and-treat strategy is highly effective in controlling hepatitis B in China.
Zu, Jian; Li, Miaolei; Zhuang, Guihua; Liang, Peifeng; Cui, Fuqiang; Wang, Fuzhen; Zheng, Hui; Liang, Xiaofeng
2018-01-01
Abstract The potential impact of increasing test-and-treat coverage on hepatitis B virus (HBV) infection remains unclear in China. The objective of this study was to develop a dynamic compartmental model at a population level to estimate the long-term effect of this strategy. Based on the natural history of HBV infection and 3 serosurvey data of hepatitis B in China, we proposed an age- and time-dependent discrete model to predict the number of new HBV infection, the number of chronic HBV infection, and the number of HBV-related deaths for the time from 2018 to 2050 under 5 different test-and-treat coverage and compared them with current intervention policy. Compared with current policy, if the test-and-treat coverage was increased to 100% since 2018, the numbers of chronic HBV infection, new HBV infection, and HBV-related deaths in 2035 would be reduced by 26.60%, 24.88%, 26.55%, respectively, and in 2050 it would be reduced by 44.93%, 43.29%, 43.67%, respectively. In contrast, if the test-and-treat coverage was increased by 10% every year since 2018, then the numbers of chronic HBV infection, new HBV infection, and HBV-related deaths in 2035 would be reduced by 21.81%, 20.10%, 21.40%, respectively, and in 2050 it would be reduced by 41.53%, 39.89%, 40.32%, respectively. In particular, if the test-and-treat coverage was increased to 75% since 2018, then the annual number of HBV-related deaths would begin to decrease from 2018. If the test-and-treat coverage was increased to above 25% since 2018, then the hepatitis B surface antigen (HBsAg) prevalence for population aged 1 to 59 years in China would be reduced to below 2% in 2035. Our model also showed that in 2035, the numbers of chronic HBV infection and HBV-related deaths in 65 to 69 age group would be reduced the most (about 1.6 million and 13 thousand, respectively). Increasing test-and-treat coverage would significantly reduce HBV infection in China, especially in the middle-aged people and older people. The earlier the treatment and the longer the time, the more significant the reduction. Implementation of test-and-treat strategy is highly effective in controlling hepatitis B in China. PMID:29668627
Corriero, Rosemary; Gay, Jennifer L; Robb, Sara Wagner; Stowe, Ellen W
2018-02-01
The purpose of the study was to compare human papillomavirus (HPV) vaccination rates before and after Affordable Care Act (ACA) implementation among women, and examine differences according to insurance status and other sociodemographic variables. This was a cross-sectional analysis of the National Health and Nutrition Examination Survey questionnaire data. Participants (n = 4599) were from a random sample of the United States population. HPV vaccination status and number of doses received according to age, income, education, race, and insurance coverage. Over time, the proportion of women reporting HPV vaccination increased from 16.4% to 27.6%, and reporting vaccination completion (3 doses) increased from 56.8% to 67.2%. After ACA implementation, respondents were 3.3 times more likely to be vaccinated compared with before ACA implementation (95% confidence interval [CI], 2.0-5.5) adjusting for age, race, and insurance coverage. Similarly, respondents were more likely to have received 2 (odds ratio, 2.8; 95% CI, 1.5-5.3) or 3 doses (odds ratio, 5.8; 95% CI, 2.5-13.6). Vaccination uptake increased in a comparison of waves of data from before and after ACA implementation. This increase in vaccination coverage could be related to the increased preventative service coverage, which includes vaccines, required by the ACA. Future studies might focus on the role insurance has on vaccination uptake, and meeting Healthy People 2020 objectives for vaccination coverage. Copyright © 2017 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.
Coffeng, Luc E; Stolk, Wilma A; Hoerauf, Achim; Habbema, Dik; Bakker, Roel; Hopkins, Adrian D; de Vlas, Sake J
2014-01-01
The African Programme for Onchocerciasis Control (APOC) is currently shifting its focus from morbidity control to elimination of infection. To enhance the likelihood of elimination and speed up its achievement, programs may consider to increase the frequency of ivermectin mass treatment from annual to 6-monthly or even higher. In a computer simulation study, we examined the potential impact of increasing the mass treatment frequency for different settings. With the ONCHOSIM model, we simulated 92,610 scenarios pertaining to different assumptions about transmission conditions, history of mass treatment, the future mass treatment strategy, and ivermectin efficacy. Simulation results were used to determine the minimum remaining program duration and number of treatment rounds required to achieve 99% probability of elimination. Doubling the frequency of treatment from yearly to 6-monthly or 3-monthly was predicted to reduce remaining program duration by about 40% or 60%, respectively. These reductions come at a cost of additional treatment rounds, especially in case of 3-monthly mass treatment. Also, aforementioned reductions are highly dependent on maintained coverage, and could be completely nullified if coverage of mass treatment were to fall in the future. In low coverage settings, increasing treatment coverage is almost just as effective as increasing treatment frequency. We conclude that 6-monthly mass treatment may only be worth the effort in situations where annual treatment is expected to take a long time to achieve elimination in spite of good treatment coverage, e.g. because of unfavorable transmission conditions or because mass treatment started recently.
Rodriguez, Hector P; Laugesen, Miriam J; Watts, Carolyn A
2010-12-01
To assess the effect of issue framing on voter support of tax increases for health insurance expansion. During October 2008, a random sample of registered voters (n=1203) were randomized to a control and two different 'framing' groups prior to being asked about their support for tax increases. The 'framing' groups listened to one of two statements: one emphasized the externalities or negative effects of the uninsured on the insured, and the other raised racial and ethnic disparities in health insurance coverage as a problem. All groups were asked the same questions: would they support tax increases to provide adequate and reliable health insurance for three groups, (1) all American citizens, (2) all children, irrespective of citizenship, and (3) all military veterans. Support for tax increases varied substantially depending on which group benefited from the expansion. Consensus on coverage for military veterans was highest (83.3%), followed by all children, irrespective of citizenship (64.7%), and all American citizens (60.1%). There was no statistically significant difference between voter support in the 'framing' and control groups or between the two frames. In multivariable analyses, political party affiliation was the strongest predictor of support. Voters agree on the need for coverage of military veterans, but are less united on the coverage of all children and American citizens. Framing was less important than party affiliation, suggesting that voters consider coverage expansions and related tax increases in terms of the characteristics of the targeted group, and their own personal political views and values rather than the broader impact of maintaining the status quo. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
DePasse, Jay V; Smith, Kenneth J; Raviotta, Jonathan M; Shim, Eunha; Nowalk, Mary Patricia; Zimmerman, Richard K; Brown, Shawn T
2017-05-01
Offering a choice of influenza vaccine type may increase vaccine coverage and reduce disease burden, but it is more costly. This study calculated the public health impact and cost-effectiveness of 4 strategies: no choice, pediatric choice, adult choice, or choice for both age groups. Using agent-based modeling, individuals were simulated as they interacted with others, and influenza was tracked as it spread through a population in Washington, DC. Influenza vaccination coverage derived from data from the Centers for Disease Control and Prevention was increased by 6.5% (range, 3.25%-11.25%), reflecting changes due to vaccine choice. With moderate influenza infectivity, the number of cases averaged 1,117,285 for no choice, 1,083,126 for pediatric choice, 1,009,026 for adult choice, and 975,818 for choice for both age groups. Averted cases increased with increased coverage and were highest for the choice-for-both-age-groups strategy; adult choice also reduced cases in children. In cost-effectiveness analysis, choice for both age groups was dominant when choice increased vaccine coverage by ≥3.25%. Offering a choice of influenza vaccines, with reasonable resultant increases in coverage, decreased influenza cases by >100,000 with a favorable cost-effectiveness profile. Clinical trials testing the predictions made based on these simulation results and deliberation of policies and procedures to facilitate choice should be considered. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Impact of a website based educational program for increasing vaccination coverage among adolescents.
Esposito, Susanna; Bianchini, Sonia; Tagliabue, Claudia; Umbrello, Giulia; Madini, Barbara; Di Pietro, Giada; Principi, Nicola
2018-04-03
Data regarding the use of technology to improve adolescent knowledge on vaccines are scarce. The main aim of this study was to evaluate whether different web-based educational programmes for adolescents might increase their vaccination coverage. Overall, 917 unvaccinated adolescents (389 males, 42.4%; mean age ± standard deviation, 14.0 ± 2.2 years) were randomized 1:1:1 into the following groups: no intervention (n = 334), website educational program only (n = 281), or website plus face to face lesson (n = 302) groups. The use of the website plus the lesson significantly increased the overall knowledge of various aspects of vaccine-preventable disease and reduced the fear of vaccines (p < 0.001). A significant increase in vaccination coverage was observed for tetanus, diphtheria, acellular pertussis and conjugated meningococcal ACYW vaccines in the 2 groups using the website (p < 0.001), and better results were observed in the group that had also received the lesson; in this last group, significant results were observed in the increase in vaccination coverage for meningococcal B vaccine (p < 0.001). Overall, the majority of the participants liked the experience of the website, although they considered it important to further discuss vaccines with parents, experts and teachers. This study is the first to evaluate website based education of adolescents while considering all of the vaccines recommended for this age group. Our results demonstrate the possibility of increasing vaccination coverage by using a website based educational program with tailored information. However, to be most effective, this program should be supplemented with face-to-face discussions of vaccines at school and at home. Thus, specific education should also include teachers and parents so that they will be prepared to discuss with adolescents what is true and false in the vaccination field.
Race, stability of health insurance coverage, and prescription medication use.
Winters, Karen P; Wyatt, Sharon B; Nick, Todd G; Hewlett, Peggy O; Hyde, John C; Fletcher, Audwin B
2010-01-01
To determine the effects of health insurance and race on prescription medication use and expense. An observational, non-experimental design was used. Multivariable regression analyses were conducted to evaluate the independent effects of health insurance status and race on prescription medication use and expense while controlling for sociodemographic, geographic, and health status characteristics. The sample consisted of 19,035 participants in the 1996 through 2003 Medical Expenditure Panel Survey. European Americans spent about $300 to $400 more and used three to four more prescriptions annually compared to other racial groups. Prescription medication expenses increased as time spent uninsured increased. Participants with part-year coverage filled four fewer prescriptions than those with full-year health insurance coverage. Participants with private coverage spent less on prescription medications compared to those with public and those with dual public and private coverage ($1,194 vs. $1,931 and $2,076, respectively; p < or = 0.001). Significant racial and health insurance status disparities in prescription medication use and expenses exist after controlling for sociodemographic, geographic, and health status characteristics.
Health coverage of low-income citizen and noncitizen wage earners: sources and disparities.
Ponce, Ninez A; Cochran, Susan D; Mays, Vickie M; Chia, Jenny; Brown, E Richard
2008-04-01
The health coverage of low-income workers represents an area of continuing disparities in the United States system of health insurance. Using the 2001 California Health Interview Survey, we estimate the effect of low-income wage earners' citizenship and gender on the odds of obtaining primary employment-based health insurance (EBHI), dependent EBHI, public program coverage, and coverage from any source. We find that noncitizen men and women who comprise 40% of California's low-income workforce, share the disadvantage of much lower rates of insurance coverage, compared to naturalized and U.S.-born citizens. However, poor coverage rates of noncitizen men, regardless of permanent residency status, result from the cumulative disadvantage in obtaining dependent EBHI and public insurance. If public policies designed to provide a health care safety net fail to address the health care coverage needs of low-wage noncitizens, health disparities will continue to increase in this group that contributes essentially to the U.S. economy.
Human papillomavirus vaccination coverage using two-dose or three-dose schedule criteria.
Lin, Xia; Rodgers, Loren; Zhu, Liping; Stokley, Shannon; Meites, Elissa; Markowitz, Lauri E
2017-10-13
In October 2016, the Advisory Committee on Immunization Practices (ACIP) updated the human papillomavirus (HPV) vaccination recommendation to include a 2-dose schedule for U.S. adolescents initiating the vaccine series before their 15th birthday. We analyzed records for >4million persons aged 9-17years receiving any HPV vaccine by the end of each quarter during January 1, 2014-September 30, 2016 from six Immunization Information Systems Sentinel Sites, and reclassified HPV vaccination up-to-date coverage according to the updated recommendations. Compared with HPV vaccination up-to-date coverage by the 3-dose schedule only, including criteria for either a 2-dose or 3-dose schedule increased up-to-date coverage in 11-12, 13-14, and 15-17 year-olds by 4.5-8.5 percentage points. The difference between 3-dose up-to-date coverage and 2- or 3-dose up-to-date coverage was greatest in late 2016. These data provide baseline HPV vaccination coverage using current ACIP recommendations. Published by Elsevier Ltd.
Hospital consolidation and racial/income disparities in health insurance coverage.
Town, Robert J; Wholey, Douglas R; Feldman, Roger D; Burns, Lawton R
2007-01-01
Non-Hispanic whites are significantly more likely to have health insurance coverage than most racial/ethnic minorities, and this differential grew during the 1990s. Similarly, wealthier Americans are more likely to have health insurance than the poor, and this difference also grew over the 1990s. This paper examines the role of provider competition in increasing these disparities in insurance coverage. Over the 1990s, the hospital industry consolidated; we analyze the impact of this consolidation on health insurance take-up for different racial/ethnic minorities and income groups. We found that the hospital consolidation wave increased health insurance disparities along racial and income dimensions.
Hopper, J A; Busbin, J W
1995-01-01
America is undergoing a profound age shift in its demographic make-up with people 55 and over comprising an increasing proportion of the population. Marketers may need to increase their response rate to this shift, especially in refining the application of marketing theory and practice to older age consumers. To this end, a survey of older couple buying behavior for health insurance coverage is reported here. Results clarify evaluative criteria and the viability of multiple market segmentation for health care coverage among older consumers as couples. Commentary on the efficacy of present health coverage marketing programs is provided.
Bouwer, S T; Hoofd, L; Kreuzer, F
2001-02-16
The purpose of this study was to verify the concept of non-equilibrium facilitated oxygen diffusion. This work succeeds our previous study, where facilitated oxygen diffusion by hemoglobin was measured at conditions of chemical equilibrium, and which yielded diffusion coefficients of hemoglobin and of oxygen. In the present work chemical non-equilibrium was induced using very thin diffusion layers. As a result, facilitation was decreased as predicted by theory. Thus, this work presents the first experimental demonstration of non-equilibrium facilitated oxygen diffusion. In addition, association and dissociation rate parameters of the reaction between oxygen and bovine and human hemoglobin were calculated and the effect of the homotropic and heterotropic interactions on each rate parameter was demonstrated. The results indicate that the homotropic interaction--which leads to increasing oxygen affinity with increasing oxygenation--is predominantly due to an increase in the association rate. The heterotropic interaction--which leads to decreasing oxygen affinity by anionic ligands--appears to be effected in two ways. Cl- increases the dissociation rate. In contrast, 2,3-diphosphoglycerate decreases the association rate.
NASA Astrophysics Data System (ADS)
Fang, Zhi; Shao, Tao; Wang, Ruixue; Yang, Jing; Zhang, Cheng
2016-04-01
The dielectric barrier discharge generated in argon/oxygen mixtures at atmospheric pressure is investigated, and the effect of oxygen content on discharge characteristics at applied voltage of 4.5 kV is studied by means of electrical measurements and optical diagnostics. The results show that the filaments in the discharge regime become more densely packed with the increasing in the oxygen content, and the distribution of the filaments is more uniform in the gap. An increase in the oxygen content results in a decrease in the average power consumed and transported charges, while there exists an optimal value of oxygen content for the production of oxygen radicals. The maximal yield of oxygen radicals is obtained in mixtures of argon with 0.3% oxygen addition, and the oxygen radicals then decrease with the further increase in the oxygen content. The oxygen/argon plasma is employed to modify surface hydrophilicity of the PET films to estimate the influence of oxygen content on the surface treatment, and the static contact angles before and after the treatments are measured. The lowest contact angle is obtained at a 0.3% addition of oxygen to argon, which is in accordance with the optimum oxygen content for oxygen radicals generation. The electron density and electron temperature are estimated from the measured current and optical emission spectroscopy, respectively. The electron density is found to reduce significantly at a higher oxygen content due to the increased electron attachment, while the estimated electron temperature do not change apparently with the oxygen content. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.
Focus and coverage of Bolsa Família Program in the Pelotas 2004 birth cohort
Schmidt, Kelen H; Labrecque, Jeremy; Santos, Iná S; Matijasevich, Alicia; Barros, Fernando C; Barros, Aluisio J D
2017-01-01
ABSTRACT OBJECTIVE To describe the focalization and coverage of Bolsa Família Program among the families of children who are part of the 2004 Pelotas birth cohort (2004 cohort). METHODS The data used derives from the integration of information from the 2004 cohort and the Cadastro Único para Programas Sociais do Governo Federal (CadÚnico – Register for Social Programs of the Federal Government), in the 2004-2010 period. We estimated the program coverage (percentage of eligible people who receive the benefit) and its focus (proportion of eligible people among the beneficiaries). We used two criteria to define eligibility: the per capita household income reported in the cohort follow-ups and belonging to the 20% poorest families according to the National Economic Indicator (IEN), an asset index. RESULTS Between 2004 and 2010, the proportion of families in the cohort that received the benefit increased from 11% to 34%. We observed an increase in all wealth quintiles. In 2010, by income and wealth quintiles (IEN), 62%-72% of the families were beneficiaries among the 20% poorest people, 2%-5% among the 20% richest people, and about 30% of families of the intermediate quintile. According to household income (minus the benefit) 29% of families were eligible in 2004 and 16% in 2010. By the same criteria, the coverage of the program increased from 43% in 2004 to 71% in 2010. In the same period, by the wealth criterion (IEN), coverage increased from 29% to 63%. The focalization of the program decreased from 78% in 2004 to 32% in 2010 according to income, and remained constant (37%) according to the IEN. CONCLUSIONS Among the families of the 2004 cohort, there was a significant increase in the program coverage, from its inception until 2010, when it was near 70%. The focus of the program was below 40% in 2010, indicating that more than half of the beneficiaries did not belong to the target population. PMID:28380211
Access to and coverage of renal replacement therapy in minorities and ethnic groups in Venezuela.
Bellorin-Font, Ezequiel; Pernalete, Nidia; Meza, Josefina; Milanes, Carmen Luisa; Carlini, Raul G
2005-08-01
Access to and coverage of renal replacement therapy in minorities and ethnic groups in Venezuela. Numerous studies have documented the presence of racial and minority disparities regarding the impact of renal disease and access to renal replacement therapy (RRT). This problem is less well documented in Latin America. Venezuela, like most countries in the region, is subject to severe constraints in the allocation of resources for high-cost chronic diseases, which limits the access of patients with chronic kidney disease to RRT. Although access to health care is universal, there is both a deficit in coverage and disparity in the access to RRT, largely as a result of socioeconomic limitations and budget constrains. With current rising trends of the incidence of end-stage renal disease (ESRD) and costs of medical technology, the long-term goal of complete RRT coverage will become increasingly out of reach. Current evidence suggests that prevention of progression of renal disease is possible at relatively low cost and broad coverage. Based on this evidence, the Ministry of Health has redesigned its policy with respect to renal disease based on 4 elements: 1. Prevention by means of early detection and referral to multidisciplinary health teams, as well as promotion of health habits in the community. 2. Prevention of progression of renal disease by pharmacologic and nonpharmacologic means. 3. An increase in the rate of coverage and reduction of disparities in the access to dialysis. 4. An increase in the rates of renal transplantation through better organ procurement programs and reinforcement of transplant centers. However, the projected increase in the number of patients with ESKD receiving RRT will represent a serious burden to the health care system. Therefore, implementation of these policies will require the involvement of international agencies as well as an adequate partnership between nephrologists and health care planners, so that meeting the increasing demands of ESKD programs may be balanced with other priorities of our national health system.
Gain in Insurance Coverage and Residual Uninsurance Under the Affordable Care Act: Texas, 2013–2016
Pickett, Stephen; Marks, Elena
2017-01-01
Objectives. To examine the effects of the Affordable Care Act’s (ACA’s) Marketplace on Texas residents and determine which population subgroups benefited the most and which the least. Methods. We analyzed insurance coverage rates among nonelderly Texas adults using the Health Reform Monitoring Survey-Texas from September 2013, just before the first open enrollment period in the Marketplace, through March 2016. Results. Texas has experienced a roughly 6–percentage-point increase in insurance coverage (from 74.7% to 80.6%; P = .012) after implementation of the major insurance provisions of the ACA. The 4 subgroups with the largest increases in adjusted insurance coverage between 2013 and 2016 were persons aged 50 to 64 years (12.1 percentage points; P = .002), Hispanics (10.9 percentage points; P = .002), persons reporting fair or poor health status (10.2 percentage points; P = .038), and those with a high school diploma as their highest educational attainment (9.2 percentage points; P = .023). Conclusions. Many population subgroups have benefited from the ACA’s Marketplace, but approximately 3 million Texas residents still lack health coverage. Adopting the ACA’s Medicaid expansion is a means to address the lack of coverage. PMID:27854535
Tunable Signal-Off and Signal-On Electrochemical Cisplatin Sensor.
Wu, Yao; Lai, Rebecca Y
2017-09-19
We report the first electrochemical cisplatin sensor fabricated with a thiolated and methylene blue (MB)-modified oligo-adenine (A)-guanine (G) DNA probe. Depending on the probe coverage, the sensor can behave as a signal-off or signal-on sensor. For the high-coverage sensor, formation of intrastrand Pt(II)-AG adducts rigidifies the oligo-AG probe, resulting in a concentration-dependent decrease in the MB signal. For the low-coverage sensor, the increase in probe-to-probe spacing enables binding of cisplatin via the intrastrand GNG motif (N = A), generating a bend in the probe which results in an increase in the MB current. Although both high-coverage signal-off and low-coverage signal-on sensors are capable of detecting cisplatin, the signal-on sensing mechanism is better suited for real time analysis of cisplatin. The low-coverage sensor has a lower limit of detection, wider optimal AC frequency range, and faster response time. It has high specificity for cisplatin and potentially other Pt(II) drugs and does not cross-react with satraplatin, a Pt(IV) prodrug. It is also selective enough to be employed directly in 50% saliva and 50% urine. This detection strategy may offer a new approach for sensitive and real time analysis of cisplatin in clinical samples.
Enhancing Political Will for Universal Health Coverage in Nigeria.
Aregbeshola, Bolaji S
2017-01-01
Universal health coverage aims to increase equity in access to quality health care services and to reduce financial risk due to health care costs. It is a key component of international health agenda and has been a subject of worldwide debate. Despite differing views on its scope and pathways to reach it, there is a global consensus that all countries should work toward universal health coverage. The goal remains distant for many African countries, including Nigeria. This is mostly due to lack of political will and commitment among political actors and policymakers. Evidence from countries such as Ghana, Chile, Mexico, China, Thailand, Turkey, Rwanda, Vietnam and Indonesia, which have introduced at least some form of universal health coverage scheme, shows that political will and commitment are key to the adoption of new laws and regulations for reforming coverage. For Nigeria to improve people's health, reduce poverty and achieve prosperity, universal health coverage must be vigorously pursued at all levels. Political will and commitment to these goals must be expressed in legal mandates and be translated into policies that ensure increased public health care financing for the benefit of all Nigerians. Nigeria, as part of a global system, cannot afford to lag behind in striving for this overarching health goal.
Pertussis vaccination coverage among French parents of infants after 10years of cocoon strategy.
Cohen, R; Gaudelus, J; Denis, F; Stahl, J-P; Chevaillier, O; Pujol, P; Martinot, A
2016-06-01
The cocoon strategy against pertussis has been recommended in France since 2004 to indirectly protect young infants who are not yet vaccinated. We aimed to measure vaccination coverage among French parents of infants. A representative sample of 300 mothers and 200 fathers of infants aged <12 months completed a self-administered online questionnaire. They all provided their own vaccination records. Overall, 87% of mothers believed vaccination against pertussis to be important; 83% reported being immunized against pertussis but their vaccination records showed that a third of them was wrong (34%). On the basis of our sample, the 2009-2014 vaccination coverage against pertussis among mothers increased from 22 to 61% (P<0.005); over the same period of time, vaccination coverage against diphtheria, tetanus, and polio remained stable (80%). Vaccination coverage against pertussis among fathers increased from 21 to 42% between 2010 and 2013 (P=0.009). In 2013, one couple out of four (26%) was adequately immunized against pertussis. The cocoon strategy was implemented 10years ago in France but vaccination coverage remains suboptimal among parents of young infants. Healthcare professionals must recommend vaccination against pertussis to young adults and check that their vaccination status is up to date. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
STEVENS, ROBIN; HORNIK, ROBERT C.
2014-01-01
This study examined the impact of newspaper coverage of HIV/AIDS on HIV testing behavior in the US population. HIV testing data were taken from the CDC’s National Behavioral Risk Factor Surveillance System (BRFSS) from 1993 to 2007 (n=265,557). News stories from 24 daily newspapers and one wire service during the same time period were content analyzed. Distributed lagged regression models were employed to estimate how well HIV/AIDS newspaper coverage predicted later HIV testing behavior. Increases in HIV/AIDS newspaper coverage were associated with declines in population level HIV testing. Each additional 100 HIV/AIDS related newspaper stories published each month was associated with a 1.7% decline in HIV testing levels in the subsequent month. This effect differed by race, with African Americans exhibiting greater declines in HIV testing subsequent to increased news coverage than did Whites. These results suggest that mainstream newspaper coverage of HIV/AIDS may have a particularly deleterious effect on African Americans, one of the groups most impacted by the disease. The mechanisms driving the negative effect deserve further investigation to improve reporting on HIV/AIDS in the media. PMID:24597895
Courtemanche, Charles; Marton, James; Ukert, Benjamin; Yelowitz, Aaron; Zapata, Daniela
2017-01-01
The Affordable Care Act (ACA) aimed to achieve nearly universal health insurance coverage in the United States through a combination of insurance market reforms, mandates, subsidies, health insurance exchanges, and Medicaid expansions, most of which took effect in 2014. This paper estimates the causal effects of the ACA on health insurance coverage in 2014 using data from the American Community Survey. We utilize difference-in-difference-in-differences models that exploit cross-sectional variation in the intensity of treatment arising from state participation in the Medicaid expansion and local area pre-ACA uninsured rates. This strategy allows us to identify the effects of the ACA in both Medicaid expansion and non-expansion states. Our preferred specification suggests that, at the average pre-treatment uninsured rate, the full ACA increased the proportion of residents with insurance by 5.9 percentage points compared to 2.8 percentage points in states that did not expand Medicaid. Private insurance expansions from the ACA were due to increases in both employer-provided and non-group coverage. The coverage gains from the full ACA were largest for those without a college degree, non-whites, young adults, unmarried individuals, and those without children in the home. We find no evidence that the Medicaid expansion crowded out private coverage.
Zambrana, Ruth E.; Carter-Pokras, Olivia
2004-01-01
OBJECTIVES: To summarize key findings on disparities in health insurance coverage for latino children, to present selected socioeconomic and healthcare access indicators for the nine states with latino populations over 500,000, and to recommend state strategies to increase public health insurance coverage for latino children. METHODS: Literature review performed on latino children and health insurance coverage, key informant interviews with frontline service providers, review of outreach sections of eight state 1115 waiver requests approved by the Secretary of the U.S. Department of Health and Human Services, and national and state data compiled on sociodemographic and healthcare access indicators for nine states with the largest latino populations. RESULTS: Eligibility and enrollment into Medicaid and State Children's Health Insurance Program (SCHIP) are hindered by financial, nonfinancial, and social policy barriers. Disparities in insurance and access indicators show that lack of parental employment-linked benefits, procedural barriers to enrollment, and lack of clarification on eligibility for children of noncitizen parents are associated with low levels of insurance coverage among latino children. CONCLUSION: To state strategies consistent with the overarching goal of Healthy People 2010 to eliminate health disparities can increase health insurance coverage for children of low-wage latino workers. PMID:15101671
Kapinos, Kandice A.
2015-01-01
Objectives. We identified correlates of racial/ethnic disparities in colorectal cancer screening and changes in disparities under state-mandated insurance coverage. Methods. Using Behavioral Risk Factor Surveillance System data, we estimated a Fairlie decomposition in the insured population aged 50 to 64 years and a regression-adjusted difference-in-difference-in-difference model of changes in screening attributable to mandates. Results. Under mandated coverage, blood stool test (BST) rates increased among Black, Asian, and Native American men, but rates among Whites also increased, so disparities did not change. Endoscopic screening rates increased by 10 percentage points for Hispanic men and 3 percentage points for non-Hispanic men. BST rates fell among Hispanic relative to non-Hispanic men. We found no changes for women. However, endoscopic screening rates improved among lower income individuals across all races and ethnicities. Conclusions. Mandates were associated with a reduction in endoscopic screening disparities only for Hispanic men but may indirectly reduce racial/ethnic disparities by increasing rates among lower income individuals. Findings imply that systematic differences in insurance coverage, or health plan fragmentation, likely existed without mandates. These findings underscore the need to research disparities within insured populations. PMID:25905835
Wright, Bernadette; Gruman, Cindy; Alecxih, Lisa; Knatterud, Larhae
2012-01-01
A major barrier to building a strong workforce to meet the growing need for long-care is lack of affordable health benefits. This study projects impacts of funding health coverage for all long-term care workers in Minnesota. Under the most cost effective model plan design, enrollment in employer-sponsored coverage would increase 73% to 100% for individual coverage and 26% to 42% for family coverage. Total monthly costs would be $698/worker in the commercial market or $634/worker through a new dedicated risk pool. Based on our findings and past research, the authors present recommendations for structuring and implementing a long-term care worker health insurance initiative.
Study on the laser irradiation characteristics of NEPE propellant in different oxygen concentrations
NASA Astrophysics Data System (ADS)
Xiang, Hengsheng; Chen, Xiong; Zhou, Changsheng
2016-01-01
The ignition and combustion characteristics of nitrate ester plasticized polyether (NEPE) propellant in different oxygen concentrations ambient gases were studied by the application of CO2 laser, infrared thermometer and high speed camera. The flame intensity data of the propellant was collected by the photodiode; propellant flame temperature was measured by infrared thermometer. The experimental results show that the time which NEPE propellant spend to be stable combustion will get shorter with the increase of oxygen concentration; the flame peak temperature measured by infrared thermometer increases with the increase of oxygen concentration when the oxygen concentration is less than 30% by volume, then decreases with the increase of oxygen concentration.
Expanded managed care liability: what impact on employer coverage?
Studdert, D M; Sage, W M; Gresenz, C R; Hensler, D R
1999-01-01
Policymakers are considering legislative changes that would increase managed care organizations' exposure to civil liability for withholding coverage or failing to deliver needed care. Using a combination of empirical information and theoretical analysis, we assess the likely responses of health plans and Employee Retirement Income Security Act (ERISA) plan sponsors to an expansion of liability, and we evaluate the policy impact of those moves. We conclude that the direct costs of liability are uncertain but that the prospect of litigation may have other important effects on coverage decision making, information exchange, risk contracting, and the extent of employers' involvement in health coverage.
Massachusetts health reform: employer coverage from employees' perspective.
Long, Sharon K; Stockley, Karen
2009-01-01
The national health reform debate continues to draw on Massachusetts' 2006 reform initiative, with a focus on sustaining employer-sponsored insurance. This study provides an update on employers' responses under health reform in fall 2008, using data from surveys of working-age adults. Results show that concerns about employers' dropping coverage or scaling back benefits under health reform have not been realized. Access to employer coverage has increased, as has the scope and quality of their coverage as assessed by workers. However, premiums and out-of-pocket costs have become more of an issue for employees in small firms.
Differential impacts of public health insurance expansions at the local level.
Baughman, Reagan
2007-03-01
Dramatic expansions in public health insurance eligibility for U.S. children have only modestly reduced the aggregate number of uninsured at the national level. This paper shows that Medicaid and SCHIP expansions had different impacts on child health insurance coverage patterns based upon local labor market characteristics. Metropolitan areas with high levels of unemployment were most likely to have seen improvements in overall insurance coverage for children between 1990 and 2001. Areas with greater fractions of employment in services, retail or wholesale trade were more likely to have experienced increases in public coverage but not overall coverage rates.
Influence of oxygen concentration on ethylene removal using dielectric barrier discharge
NASA Astrophysics Data System (ADS)
Takahashi, Katsuyuki; Motodate, Takuma; Takaki, Koichi; Koide, Shoji
2018-01-01
Ethylene gas is decomposed using a dielectric barrier discharge plasma reactor for long-period preservation of fruits and vegetables. The oxygen concentration in ambient gas is varied from 2 to 20% to simulate the fruit and vegetable transport container. The experimental results show that the efficiency of ethylene gas decomposition increases with decreasing oxygen concentration. The reactions of ethylene molecules with ozone are analyzed by Fourier transform infrared spectrometry. The analysis results show that the oxidization process by ozone is later than that by oxygen atoms. The amount of oxygen atoms that contribute to ethylene removal increases with decreasing oxygen concentration because the reaction between oxygen radicals and oxygen molecules is suppressed at low oxygen concentrations. Ozone is completely removed and the energy efficiency of C2H4 removal is increased using manganese dioxide as a catalyst.
Nemer, Sérgio Nogueira; Caldeira, Jefferson B; Santos, Ricardo G; Guimarães, Bruno L; Garcia, João Márcio; Prado, Darwin; Silva, Ricardo T; Azeredo, Leandro M; Faria, Eduardo R; Souza, Paulo Cesar P
2015-12-01
To verify whether high positive end-expiratory pressure levels can increase brain tissue oxygen pressure, and also their effects on pulse oxygen saturation, intracranial pressure, and cerebral perfusion pressure. Twenty traumatic brain injury patients with acute respiratory distress syndrome were submitted to positive end-expiratory pressure levels of 5, 10, and 15 cm H2O progressively. The 3 positive end-expiratory pressure levels were used during 20 minutes for each one, whereas brain tissue oxygen pressure, oxygen saturation, intracranial pressure, and cerebral perfusion pressure were recorded. Brain tissue oxygen pressure and oxygen saturation increased significantly with increasing positive end-expiratory pressure from 5 to 10 and from 10 to 15 cm H2O (P=.0001 and P=.0001 respectively). Intracranial pressure and cerebral perfusion pressure did not differ significantly with increasing positive end-expiratory pressure from 5 to 10 and from 10 to 15 cm H2O (P=.16 and P=.79 respectively). High positive end-expiratory pressure levels increased brain tissue oxygen pressure and oxygen saturation, without increase in intracranial pressure or decrease in cerebral perfusion pressure. High positive end-expiratory pressure levels can be used in severe traumatic brain injury patients with acute respiratory distress syndrome as a safe alternative to improve brain oxygenation. Copyright © 2015 Elsevier Inc. All rights reserved.
Wallace, Cate; Corben, Paul; Turahui, John; Gilmour, Robin
2008-10-01
North Coast Area Health Service (NCAHS) conducted a seven week television advertising campaign to raise community awareness of the availability of free adult pneumococcal vaccination and to increase coverage among North Coast residents in high risk groups. Effectiveness of the campaign was evaluated by examining vaccine ordering patterns of North Coast vaccination providers from 2005/2006 as a proxy for vaccination coverage. In the months during and immediately following (June-September 2006) the advertising campaign, a significantly higher proportion of vaccines were despatched to North Coast immunisation service providers. The advertising campaign was an effective strategy to promote vaccination among NCAHS residents not immunised in the first year of the National Pneumococcal Program for Older Australians. This higher immunisation coverage is expected to contribute to the statewide trend of significant reductions in invasive pneumococcal disease (IPD) notifications.
Keehan, Sean P; Sisko, Andrea M; Truffer, Christopher J; Poisal, John A; Cuckler, Gigi A; Madison, Andrew J; Lizonitz, Joseph M; Smith, Sheila D
2011-08-01
In 2010, US health spending is estimated to have grown at a historic low of 3.9 percent, due in part to the effects of the recently ended recession. In 2014, national health spending growth is expected to reach 8.3 percent when major coverage expansions from the Affordable Care Act of 2010 begin. The expanded Medicaid and private insurance coverage are expected to increase demand for health care significantly, particularly for prescription drugs and physician and clinical services. Robust growth in Medicare enrollment, expanded Medicaid coverage, and premium and cost-sharing subsidies for exchange plans are projected to increase the federal government share of health spending from 27 percent in 2009 to 31 percent by 2020. This article provides perspective on how the nation's health care dollar will be spent over the coming decade as the health sector moves quickly toward its new paradigm of expanded insurance coverage.
Simulation studies on structural and thermal properties of alkane thiol capped gold nanoparticles.
Devi, J Meena
2017-06-01
The structural and thermal properties of the passivated gold nanoparticles were explored employing molecular dynamics simulation for the different surface coverage densities of the self-assembled monolayer (SAM) of alkane thiol. The structural properties of the monolayer protected gold nanoparticles such us overall shape, organization and conformation of the capping alkane thiol chains were found to be influenced by the capping density. The structural order of the thiol capped gold nanoparticles enhances with the increase in the surface coverage density. The specific heat capacity of the alkane thiol capped gold nanoparticles was found to increase linearly with the thiol coverage density. This may be attributed to the enhancement in the lattice vibrational energy. The present simulation results suggest, that the structural and thermal properties of the alkane thiol capped gold nanoparticles may be modified by the suitable selection of the SAM coverage density. Copyright © 2017 Elsevier Inc. All rights reserved.
Increased Transparency and Consumer Protections for 2016 Marketplace Plans.
Brooks-LaSure, Chiquita
2015-12-01
The open enrollment period that ends in December 2015 for coverage beginning January 2016 marks the third year of the health care exchanges or marketplaces and of coverage through new qualified health plans. This issue brief investigates several key changes to the qualified health plans, with a focus on increased transparency and consumer protections. A new out-of-pocket costs calculator, requirements regarding provider networks, and prescription drug cost-sharing requirements should serve to better inform and improve consumer selection. In addition, several policy changes will help individuals with more severe health needs. These include: improved prescription drug coverage for HIV/ AIDS and other conditions, allowing prescription drugs that are obtained through the "exceptions" process to count toward the out-of-pocket spending cap, more comprehensive and consistent habilitative coverage, and an individual out-of-pocket spending cap within the family out-of-pocket maximum.
Mallya, Apoorva; Sandhu, Hardeep; Anya, Blanche-Philomene; Yusuf, Nasir; Ntakibirora, Marcelline; Hasman, Andreas; Fahmy, Kamal; Agbor, John; Corkum, Melissa; Sumaili, Kyandindi; Siddique, Anisur Rahman; Bammeke, Jane; Braka, Fiona; Andriamihantanirina, Rija; Ziao, Antoine-Marie C.; Djumo, Clement; Yapi, Moise Desire; Sosler, Stephen; Eggers, Rudolf
2017-01-01
Abstract Nine polio areas of expertise were applied to broader immunization and mother, newborn and child health goals in ten focus countries of the Polio Eradication Endgame Strategic Plan: policy & strategy development, planning, management and oversight (accountability framework), implementation & service delivery, monitoring, communications & community engagement, disease surveillance & data analysis, technical quality & capacity building, and partnerships. Although coverage improvements depend on multiple factors and increased coverage cannot be attributed to the use of polio assets alone, 6 out of the 10 focus countries improved coverage in three doses of diphtheria tetanus pertussis containing vaccine between 2013 and 2015. Government leadership, evidence-based programming, country-driven comprehensive operational annual plans, community partnership and strong accountability systems are critical for all programs and polio eradication has illustrated these can be leveraged to increase immunization coverage and equity and enhance global health security in the focus countries. PMID:28838187
Rachul, Christen; Caulfield, Timothy
2015-08-25
Previous studies have demonstrated how the media has an influence on policy decisions and healthcare coverage. Studies of Canadian media have shown that news coverage often emphasizes and hypes certain aspects of high profile health debates. We hypothesized that in Canadian media coverage of access to healthcare issues about therapies and technologies including for rare diseases, the media would be largely sympathetic towards patients, thus adding to public debate that largely favors increased access to healthcare-even in the face of equivocal evidence regarding efficacy. In order to test this hypothesis, we conducted a content analysis of 530 news articles about access to health therapies and technologies from 15 major Canadian newspapers over a 10-year period. Articles were analyzed for the perspectives presented in the articles and the types of reasons or arguments presented either for or against the particular access issue portrayed in the news articles. We found that news media coverage was largely sympathetic towards increasing healthcare funding and ease of access to healthcare (77.4 %). Rare diseases and orphan drugs were the most common issues raised (22.6 %). Patients perspectives were often highlighted in articles (42.3 %). 96.8 % of articles discussed why access to healthcare needs to increase, and discussion that questioned increased access was only included in 33.6 % articles. We found that news media favors a patient access ethos, which may contribute to a difficult policy-making environment.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chong, Leebyn; Lai, Yungchieh; Gray, McMahan
Separating oil from saltwater is a process relevant to some industries and may be aided by bubble and froth generation. Simulating saltwater–air interfaces adsorbed with surfactants and oil molecules can assist in understanding froth stability to improve separation. Here, combining with surface tension experimental measurements, in this work we employ molecular dynamics with a united-atom force field to linear alkane oil and three surfactant frothers, methyl isobutyl carbinol (MIBC), terpineol, and ethyl glycol butyl ether (EGBE), to investigate their synergistic behaviors for oil separation. The interfacial phenomena were measured for a range of frother surface coverages on saltwater. Density profilesmore » of the hydrophilic and hydrophobic portions of the frothers show an expected orientation of alcohol groups adsorbing to the polar water. A decrease in surface tension with increasing surface coverage of MIBC and terpineol was observed and reflected in experiments where the frother concentration increased. Relations between surface coverage and bulk concentration were observed by comparing the surface tension decreases. Additionally, a range of oil surface coverages was explored when the interface has a thin layer of adsorbed frother molecules. Finally, the obtained results indicate that an increase in surface coverage of oil molecules led to an increase in surface tension for all frother types and the pair correlation functions depicted MIBC and terpineol as having higher distributions with water at closer distances than with oil.« less
Chong, Leebyn; Lai, Yungchieh; Gray, McMahan; ...
2017-06-16
Separating oil from saltwater is a process relevant to some industries and may be aided by bubble and froth generation. Simulating saltwater–air interfaces adsorbed with surfactants and oil molecules can assist in understanding froth stability to improve separation. Here, combining with surface tension experimental measurements, in this work we employ molecular dynamics with a united-atom force field to linear alkane oil and three surfactant frothers, methyl isobutyl carbinol (MIBC), terpineol, and ethyl glycol butyl ether (EGBE), to investigate their synergistic behaviors for oil separation. The interfacial phenomena were measured for a range of frother surface coverages on saltwater. Density profilesmore » of the hydrophilic and hydrophobic portions of the frothers show an expected orientation of alcohol groups adsorbing to the polar water. A decrease in surface tension with increasing surface coverage of MIBC and terpineol was observed and reflected in experiments where the frother concentration increased. Relations between surface coverage and bulk concentration were observed by comparing the surface tension decreases. Additionally, a range of oil surface coverages was explored when the interface has a thin layer of adsorbed frother molecules. Finally, the obtained results indicate that an increase in surface coverage of oil molecules led to an increase in surface tension for all frother types and the pair correlation functions depicted MIBC and terpineol as having higher distributions with water at closer distances than with oil.« less
Overcoming Spatial and Temporal Barriers to Public Access Defibrillators Via Optimization.
Sun, Christopher L F; Demirtas, Derya; Brooks, Steven C; Morrison, Laurie J; Chan, Timothy C Y
2016-08-23
Immediate access to an automated external defibrillator (AED) increases the chance of survival for out-of-hospital cardiac arrest (OHCA). Current deployment usually considers spatial AED access, assuming AEDs are available 24 h a day. The goal of this study was to develop an optimization model for AED deployment, accounting for spatial and temporal accessibility, to evaluate if OHCA coverage would improve compared with deployment based on spatial accessibility alone. This study was a retrospective population-based cohort trial using data from the Toronto Regional RescuNET Epistry cardiac arrest database. We identified all nontraumatic public location OHCAs in Toronto, Ontario, Canada (January 2006 through August 2014) and obtained a list of registered AEDs (March 2015) from Toronto Paramedic Services. Coverage loss due to limited temporal access was quantified by comparing the number of OHCAs that occurred within 100 meters of a registered AED (assumed coverage 24 h per day, 7 days per week) with the number that occurred both within 100 meters of a registered AED and when the AED was available (actual coverage). A spatiotemporal optimization model was then developed that determined AED locations to maximize OHCA actual coverage and overcome the reported coverage loss. The coverage gain between the spatiotemporal model and a spatial-only model was computed by using 10-fold cross-validation. A total of 2,440 nontraumatic public OHCAs and 737 registered AED locations were identified. A total of 451 OHCAs were covered by registered AEDs under assumed coverage 24 h per day, 7 days per week, and 354 OHCAs under actual coverage, representing a coverage loss of 21.5% (p < 0.001). Using the spatiotemporal model to optimize AED deployment, a 25.3% relative increase in actual coverage was achieved compared with the spatial-only approach (p < 0.001). One in 5 OHCAs occurred near an inaccessible AED at the time of the OHCA. Potential AED use was significantly improved with a spatiotemporal optimization model guiding deployment. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Oxygen induces mutation in a strict anaerobe, Prevotella melaninogenica.
Takumi, Shota; Komatsu, Masaharu; Aoyama, Kohji; Watanabe, Kunitomo; Takeuchi, Toru
2008-05-15
Strict anaerobes are highly sensitive to oxygen, but the mutagenicity of oxygen in strict anaerobes has not been well understood. Prevotella melaninogenica, a strict anaerobe, is susceptible to oxygen and shows an increase in oxidative DNA damage upon exposure to oxygen. In this study, we have investigated the mutagenicity of oxygen and the types of mutations induced by oxygen. Exposure to oxygen decreased cell survival and increased the levels of 8-oxo-deoxyguanosine (8-oxodG). The frequency of rifampicin-resistant mutants was markedly increased after exposure to oxygen. After sequencing a 254-bp fragment of the rpoB gene, which encodes the beta subunit of bacterial RNA polymerase, a target molecule of rifampicin, we found that most mutants induced by oxygen had GC to TA transversions, a signature of 8-oxodG. In addition, all detected single-nucleotide changes would lead to amino acid changes that confer rifampicin resistance. These results indicate that oxygen is mutagenic in a strict anaerobe, P. melaninogenica, and its mutagenic characteristics could be analyzed with this experimental system.
The distribution of cataract surgery services in a public health eye care program in Nepal.
Marseille, E; Brand, R
1997-11-01
The cost-effectiveness of public health cataract programs in low-income countries has been well documented. Equity, another important dimension of program quality which has received less attention is analyzed here by comparisons of surgical coverage rates for major sub-groups within the intended beneficiary population of the Nepal blindness program (NBP). Substantial differences in surgical coverage were found between males and females and between different age groups of the same gender. Among the cataract blind, the surgical coverage of males was 70% higher than that of females. For both genders, the cataract blind over 55 received proportionately fewer services than younger people blind from cataract. Blind males aged 45-54 had a 500% higher rate of surgical coverage than blind males over 65. Blind females aged 35-44 had nearly a 600% higher rate of surgical coverage than blind females over 65. There was wide variation in overall surgical coverage between geographic zones, but little variation by terrain type, an indicator of the logistical difficulties in delivery of services. Members of the two highest caste groupings had somewhat lower surgical coverage than members of lower castes. Program managers should consider developing methods to increase services to women and to those over 65. Reaching these populations will become increasingly important as those most readily served receive surgery and members of the under-served groups form a growing portion of the remaining cataract backlog.
Exploring the relationship between population density and maternal health coverage
2012-01-01
Background Delivering health services to dense populations is more practical than to dispersed populations, other factors constant. This engenders the hypothesis that population density positively affects coverage rates of health services. This hypothesis has been tested indirectly for some services at a local level, but not at a national level. Methods We use cross-sectional data to conduct cross-country, OLS regressions at the national level to estimate the relationship between population density and maternal health coverage. We separately estimate the effect of two measures of density on three population-level coverage rates (6 tests in total). Our coverage indicators are the fraction of the maternal population completing four antenatal care visits and the utilization rates of both skilled birth attendants and in-facility delivery. The first density metric we use is the percentage of a population living in an urban area. The second metric, which we denote as a density score, is a relative ranking of countries by population density. The score’s calculation discounts a nation’s uninhabited territory under the assumption those areas are irrelevant to service delivery. Results We find significantly positive relationships between our maternal health indicators and density measures. On average, a one-unit increase in our density score is equivalent to a 0.2% increase in coverage rates. Conclusions Countries with dispersed populations face higher burdens to achieve multinational coverage targets such as the United Nations’ Millennial Development Goals. PMID:23170895
Steinhausen, M F; Sandblom, E; Eliason, E J; Verhille, C; Farrell, A P
2008-12-01
The mechanism underlying the decrease in aerobic scope in fish at warm temperatures is not fully understood and is the focus of this research. Our study examined oxygen uptake and delivery in resting, swimming and recovering sockeye salmon while water temperature was acutely increased from 15 degrees C to 24 degrees C in 2 degrees C h(-1) increments. Fish swam at a constant speed during the temperature change. By simultaneously measuring oxygen consumption (M(O(2))), cardiac output (Q) and the blood oxygen status of arterial and venous blood, we were able to determine where in the oxygen cascade a limitation appeared when fish stopped sustained swimming as temperature increased. High temperature fatigue of swimming sockeye salmon was not a result of a failure of either oxygen delivery to the gills or oxygen diffusion at the gills because oxygen partial pressure (P(O(2))) and oxygen content (C(O(2))) in arterial blood did not decrease with increasing temperature, as would be predicted for such limitations. Instead, arterial oxygen delivery (Ta(O(2))) was initially hampered due to a failure to adequately increase Q with increasing temperature. Subsequently, lactate appeared in the blood and venous P(O(2)) remained constant.
Russell, W J; James, M F
2000-12-01
Theoretically, if the cardiac output were increased in the presence of a given intrapulmonary shunt, the arterial haemoglobin oxygen saturation (SaO2) should improve as the venous oxygen extraction per ml of blood decreases. To test this hypothesis, eight pigs were subjected to one-lung ventilation and adrenaline and isoprenaline infusions used to increase the cardiac output. The mixed venous oxygen, shunt fraction and oxygen consumption were measured. With both adrenaline and isoprenaline, although there was a small rise in mixed venous oxygen content, there was a fall in SaO2. With adrenaline, the mean shunt rose from 48% to 65%, the mean oxygen consumption rose from 126 ml/min to 134 ml/min and the mean SaO2 fell from 86.9% to 82.5%. With isoprenaline, the mean shunt rose from 45% to 59%, the mean oxygen consumption rose from 121 ml/min to 137 ml/min and the mean SaO2 fell from 89.5% to 84.7%. It is concluded that potential improvement in SaO2, which might occur from a catecholamine-induced increase in mixed venous oxygen content during one-lung ventilation, is more than offset by increased shunting and oxygen consumption which reduce SaO2.
Intraoperative Oxygen Consumption During Liver Transplantation.
Shibata, M; Matsusaki, T; Kaku, R; Umeda, Y; Yagi, T; Morimatsu, H
2015-12-01
The aim of this study was to investigate the changes in oxygen consumption during liver transplantation and to examine the relationship between intraoperatively elevated systemic oxygen consumption and postoperative liver function. This study was performed in 33 adult patients undergoing liver transplantation between September 2011 and March 2014. We measured intraoperative oxygen consumption through the use of indirect calorimetry, preoperative and intraoperative data, liver function tests, and postoperative complications and outcomes. The mean age of patients was 52 ± 9.7 years; 14 (42%) of them were women. Average Model for End-Stage Liver Disease scores were 20 ± 8.9. Oxygen consumption significantly increased after reperfusion from 172 ± 30 mL/min during the anhepatic phase to 209 ± 30 mL/min (P < .0001). We divided patients into 2 groups according to the increase in oxygen consumption after reperfusion (oxygen consumption after reperfusion minus anhepatic phase oxygen consumption: 40 mL/min increase as cutoff). The higher consumption group had a longer cold ischemia time and higher postoperative aspartate aminotransferase and alanine aminotransferase levels as compared with the lower oxygen consumption group. There were no statistically significant differences in major postoperative complications, but the higher oxygen consumption group tended to have shorter hospital stays than the lower consumption group (58 versus 95 days). We have demonstrated that oxygen consumption significantly increased after reperfusion. Furthermore, this increased oxygen consumption was associated with a longer cold ischemia time and shorter hospital stays. Copyright © 2015 Elsevier Inc. All rights reserved.
Ionospheric irregularities and acoustic/gravity wave activity above low-latitude thunderstorms
Lay, Erin H.
2017-12-18
Ionospheric irregularities due to plasma bubbles, scintillation, and acoustic/gravity waves are studied in the low-latitude ionosphere in relation to thunderstorm activity. Ionospheric total electron content (TEC) measurements from the Low Latitude Ionospheric Sensor Network (LISN) and lightning measurements from the World-Wide Lightning Location Network (WWLLN) are compared during two summer months and two winter months in 2013. Large amplitude fluctuations in TEC are found to have a strongly-peaked diurnal pattern in the late evening and nighttime summer ionosphere. The maximum magnitude and coverage area of these fluctuations increases as thunderstorm area increases. Summertime mid-amplitude fluctuations do not exhibit the samemore » diurnal variation, but do increase in magnitude and coverage area as thunderstorm area increases. Wintertime ionospheric fluctuations do not appear to be related to thunderstorm activity. Lastly, these findings show that thunderstorms have an observable effect on magnitude and coverage area of ionospheric fluctuations.« less
Dillender, Marcus
2014-07-01
Little is known about how health insurance affects labor market decisions for young adults. This is despite the fact that expanding coverage for people in their early 20s is an important component of the Affordable Care Act. This paper studies how having an outside source of health insurance affects wages by using variation in health insurance access that comes from states extending dependent coverage to young adults. Using American Community Survey and Census data, I find evidence that extending health insurance to young adults raises their wages. The increases in wages can be explained by increases in human capital and the increased flexibility in the labor market that comes from people no longer having to rely on their own employers for health insurance. The estimates from this paper suggest the Affordable Care Act will lead to wage increases for young adults. Copyright © 2014 Elsevier B.V. All rights reserved.
Ionospheric irregularities and acoustic/gravity wave activity above low-latitude thunderstorms
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lay, Erin H.
Ionospheric irregularities due to plasma bubbles, scintillation, and acoustic/gravity waves are studied in the low-latitude ionosphere in relation to thunderstorm activity. Ionospheric total electron content (TEC) measurements from the Low Latitude Ionospheric Sensor Network (LISN) and lightning measurements from the World-Wide Lightning Location Network (WWLLN) are compared during two summer months and two winter months in 2013. Large amplitude fluctuations in TEC are found to have a strongly-peaked diurnal pattern in the late evening and nighttime summer ionosphere. The maximum magnitude and coverage area of these fluctuations increases as thunderstorm area increases. Summertime mid-amplitude fluctuations do not exhibit the samemore » diurnal variation, but do increase in magnitude and coverage area as thunderstorm area increases. Wintertime ionospheric fluctuations do not appear to be related to thunderstorm activity. Lastly, these findings show that thunderstorms have an observable effect on magnitude and coverage area of ionospheric fluctuations.« less
Ionospheric Irregularities and Acoustic/Gravity Wave Activity Above Low-Latitude Thunderstorms
NASA Astrophysics Data System (ADS)
Lay, Erin H.
2018-01-01
Ionospheric irregularities due to plasma bubbles, scintillation, and acoustic/gravity waves are studied in the low-latitude ionosphere in relation to thunderstorm activity. Ionospheric total electron content (TEC) measurements from the Low Latitude Ionospheric Sensor Network and lightning measurements from the World-Wide Lightning Location Network are compared during two summer months and two winter months in 2013. Large amplitude fluctuations in TEC are found to have a strongly peaked diurnal pattern in the late evening and nighttime summer ionosphere. The maximum magnitude and coverage area of these fluctuations increases as thunderstorm area increases. Summertime midamplitude fluctuations do not exhibit the same diurnal variation but do increase in magnitude and coverage area as thunderstorm area increases. Wintertime ionospheric fluctuations do not appear to be related to thunderstorm activity. These findings show that thunderstorms have an observable effect on magnitude and coverage area of ionospheric fluctuations.
Carlin, Caroline S; Fertig, Angela R; Dowd, Bryan E
2016-09-01
Patient cost sharing for contraceptive prescriptions was eliminated for certain insurance plans as part of the Affordable Care Act. We examined the impact of this change on women's patterns of choosing prescription contraceptive methods. Using claims data for a sample of midwestern women ages 18-46 with employer-sponsored coverage, we examined the contraceptive choices made by women in employer groups whose coverage complied with the mandate, compared to the choices of women in groups whose coverage did not comply. We found that the reduction in cost sharing was associated with a 2.3-percentage-point increase in the choice of any prescription contraceptive, relative to the 30 percent rate of choosing prescription contraceptives before the change in cost sharing. A disproportionate share of this increase came from increased selection of long-term contraception methods. Thus, the removal of cost as a barrier seems to be an important factor in contraceptive choice, and our findings about long-term methods may have implications for rates of unintended pregnancy that require further study. Project HOPE—The People-to-People Health Foundation, Inc.
Ratnaraj, Jebadurai; Kabon, Barbara; Talcott, Michael R.; Sessler, Daniel I.
2005-01-01
Oxidative killing by neutrophils, a primary defense against surgical pathogens, is directly related to tissue oxygenation. We tested the hypothesis that supplemental inspired oxygen or mild hypercapnia (end-tidal PCO2 of 50 mmHg) improves intestinal oxygenation. Pigs (25±2.5 kg) were used in two studies in random order: 1) Oxygen Study — 30% vs. 100% inspired oxygen concentration at an end-tidal PCO2 of 40 mmHg, and 2) Carbon Dioxide Study — end-tidal PCO2 of 30 mmHg vs. 50 mmHg with 30% oxygen. Within each study, treatment order was randomized. Treatments were maintained for 1.5 hours; measurements were averaged over the final hour. A tonometer inserted in the subcutaneous tissue of the left upper foreleg measured subcutaneous oxygen tension. Tonometers inserted into the intestinal wall measured intestinal intramural oxygen tension from the small and large intestines. 100% oxygen administration doubled subcutaneous oxygen partial pressure (PO2) (57±10 to 107±48 mmHg, P=0.006) and large intestine intramural PO2 (53±14 to 118±72 mmHg, P=0.014); intramural PO2increased 40% in the small intestine (37±10 to 52±25 mmHg, P=0.004). An end-tidal PCO2 of 50 mmHg increased large intestinal PO2 approximately 16% (49±10 to 57±12 mmHg, P=0.039), while intramural PO2 increased by 45% in the small intestine (31±12 to 44±16 mmHg, P=0.002). Supplemental oxygen and mild hypercapnia each increased subcutaneous and intramural tissue PO2, with supplemental oxygen being most effective. PMID:15281531
Metal/silicon Interfaces and Their Oxidation Behavior - Photoemission Spectroscopy Analysis.
NASA Astrophysics Data System (ADS)
Yeh, Jyh-Jye
Synchrotron radiation photoemission spectroscopy was used to study Ni/Si and Au/Si interface properties on the atomic scale at room temperature, after high temperature annealing and after oxygen exposures. Room temperature studies of metal/Si interfaces provide background for an understanding of the interface structure after elevated temperature annealing. Oxidation studies of Si surfaces covered with metal overlayers yield insight about the effect of metal atoms in the Si oxidation mechanisms and are useful in the identification of subtle differences in bonding relations between atoms at the metal/Si interfaces. Core level and valence band spectra with variable surface sensitivities were used to study the interactions between metal, Si, and oxygen for metal coverages and oxide thickness in the monolayer region. Interface morphology at the initial stage of metal/Si interface formation and after oxidation was modeled on the basis of the evolutions of metal and Si signals at different probing depths in the photoemission experiment. Both Ni/Si and Au/Si interfaces formed at room temperature have a diffusive region at the interface. This is composed of a layer of metal-Si alloy, formed by Si outdiffusion into the metal overlayer, above a layer of interstitial metal atoms in the Si substrate. Different atomic structures of these two regions at Ni/Si interface can account for the two different growth orientations of epitaxial Ni disilicides on the Si(111) surface after thermal annealing. Annealing the Au/Si interface at high temperature depletes all the Au atoms except for one monolayer of Au on the Si(111) surface. These phenomena are attributed to differences in the metal-Si chemical bonding relations associated with specific atomic structures. After oxygen exposures, both the Ni disilicide surface and Au covered Si surfaces (with different coverages and surface orderings) show silicon in higher oxidation states, in comparison to oxidized silicon on a clean surface. Preferential Si dioxide growth on the Au/Si surface is related to the strong distortion of the Si lattice when Au-Si bonds are formed. In comparison, a monolayer of Ni on a Si surface, with its weaker Ni-Si bond, does not enhance oxide formation.
Reeves, Aaron; Gourtsoyannis, Yannis; Basu, Sanjay; McCoy, David; McKee, Martin; Stuckler, David
2015-07-18
How to finance progress towards universal health coverage in low-income and middle-income countries is a subject of intense debate. We investigated how alternative tax systems affect the breadth, depth, and height of health system coverage. We used cross-national longitudinal fixed effects models to assess the relationships between total and different types of tax revenue, health system coverage, and associated child and maternal health outcomes in 89 low-income and middle-income countries from 1995-2011. Tax revenue was a major statistical determinant of progress towards universal health coverage. Each US$100 per capita per year of additional tax revenues corresponded to a yearly increase in government health spending of $9.86 (95% CI 3.92-15.8), adjusted for GDP per capita. This association was strong for taxes on capital gains, profits, and income ($16.7, 9.16 to 24.3), but not for consumption taxes on goods and services (-$4.37, -12.9 to 4.11). In countries with low tax revenues (<$1000 per capita per year), an additional $100 tax revenue per year substantially increased the proportion of births with a skilled attendant present by 6.74 percentage points (95% CI 0.87-12.6) and the extent of financial coverage by 11.4 percentage points (5.51-17.2). Consumption taxes, a more regressive form of taxation that might reduce the ability of the poor to afford essential goods, were associated with increased rates of post-neonatal mortality, infant mortality, and under-5 mortality rates. We did not detect these adverse associations with taxes on capital gains, profits, and income, which tend to be more progressive. Increasing domestic tax revenues is integral to achieving universal health coverage, particularly in countries with low tax bases. Pro-poor taxes on profits and capital gains seem to support expanding health coverage without the adverse associations with health outcomes observed for higher consumption taxes. Progressive tax policies within a pro-poor framework might accelerate progress toward achieving major international health goals. Commission of the European Communities (FP7-DEMETRIQ), the European Union's HRES grants, and the Wellcome Trust. Copyright © 2015 Reeves et al. Open Access article distributed under the terms of CC BY. Published by Elsevier Ltd.. All rights reserved.
Dostert, Karl-Heinz; O'Brien, Casey P.; Mirabella, Francesca; Ivars-Barceló, Francisco
2016-01-01
Atomistic-level understanding of the interaction of α,β-unsaturated aldehydes and their derivatives with late transition metals is of fundamental importance for the rational design of new catalytic materials with the desired selectivity towards C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C vs. CO bond partial hydrogenation. In this study, we investigate the interaction of acrolein, and its partial hydrogenation products propanal and allyl alcohol, with Pd(111) as a prototypical system. A combination of infrared reflection–absorption spectroscopy (IRAS) and temperature programmed desorption (TPD) experiments was applied under well-defined ultrahigh vacuum (UHV) conditions to obtain detailed information on the adsorption geometries of acrolein, propanal, and allyl alcohol as a function of coverage. We compare the IR spectra obtained for multilayer coverages, reflecting the molecular structure of unperturbed molecules, with the spectra acquired for sub-monolayer coverages, at which the chemical bonds of the molecules are strongly distorted. Coverage-dependent IR spectra of acrolein on Pd(111) point to the strong changes in the adsorption geometry with increasing acrolein coverage. Acrolein adsorbs with the CC and CO bonds lying parallel to the surface in the low coverage regime and changes its geometry to a more upright orientation with increasing coverage. TPD studies indicate decomposition of the species adsorbed in the sub-monolayer regime upon heating. Similar strong coverage dependence of the IR spectra were found for propanal and allyl alcohol. For all investigated molecules a detailed assignment of vibrational bands is reported. PMID:27149902
Immunization coverage among Hispanic ancestry, 2003 National Immunization Survey.
Darling, Natalie J; Barker, Lawrence E; Shefer, Abigail M; Chu, Susan Y
2005-12-01
The Hispanic population is increasing and heterogeneous (Hispanic refers to persons of Spanish, Hispanic, or Latino descent). The objective was to examine immunization rates among Hispanic ancestry for the 4:3:1:3:3 series (> or = 4 doses diphtheria, tetanus toxoids, and pertussis vaccine; > or = 3 doses poliovirus vaccine; > or = 1 doses measles-containing vaccine; > or = 3 doses Haemophilus influenzae type b vaccine; and > or = 3 doses hepatitis B vaccine). The National Immunization Survey measures immunization coverage among 19- to 35-month-old U.S. children. Coverage was compared from combined 2001-2003 data among Hispanics and non-Hispanic whites using t-tests, and among Hispanic ancestry using a chi-square test. Hispanics were categorized as Mexican, Mexican American, Central American, South American, Puerto Rican, Cuban, Spanish Caribbean (primarily Dominican Republic), other, and multiple ancestry. Children of Hispanic ancestry increased from 21% in 1999 to 25% in 2003. These Hispanic children were less well immunized than non-Hispanic whites (77.0%, +/-2.1% [95% confidence interval] compared to 82.5%, +/-1.1% (95% CI) > in 2003). Immunization coverage did not vary significantly among Hispanics of varying ancestries (p=0.26); however, there was substantial geographic variability. In some areas, immunization coverage among Hispanics was significantly higher than non-Hispanic whites. Hispanic children were less well immunized than non-Hispanic whites; however, coverage varied notably by geographic area. Although a chi-square test found no significant differences in coverage among Hispanic ancestries, the range of coverage, 79.2%, +/-5.1% for Cuban Americans to 72.1%, +/-2.4% for Mexican descent, may suggest a need for improved and more localized monitoring among Hispanic communities.
Mallin, Michael A; Johnson, Virginia L; Ensign, Scott H
2009-12-01
Water quality data at 12 sites within an urban, a suburban, and a rural stream were collected contemporaneously during four wet and eight dry periods. The urban stream yielded the highest biochemical oxygen demand (BOD), orthophosphate, total suspended sediment (TSS), and surfactant concentrations, while the most rural stream yielded the highest total organic carbon concentrations. Percent watershed development and percent impervious surface coverage were strongly correlated with BOD (biochemical oxygen demand), orthophosphate, and surfactant concentrations but negatively with total organic carbon. Excessive fecal coliform abundance most frequently occurred in the most urbanized catchments. Fecal coliform bacteria, TSS, turbidity, orthophosphate, total phosphorus, and BOD were significantly higher during rain events compared to nonrain periods. Total rainfall preceding sampling was positively correlated with turbidity, TSS, BOD, total phosphorus, and fecal coliform bacteria concentrations. Turbidity and TSS were positively correlated with phosphorus, fecal coliform bacteria, BOD, and chlorophyll a, which argues for better sedimentation controls under all landscape types.
Szabó, Zsolt; Gyula, Péter; Robotka, Hermina; Bató, Emese; Gálik, Bence; Pach, Péter; Pekker, Péter; Papp, Ildikó; Bihari, Zoltán
2015-01-01
Methylibium sp. strain T29 was isolated from a gasoline-contaminated aquifer and proved to have excellent capabilities in degrading some common fuel oxygenates like methyl tert-butyl ether, tert-amyl methyl ether and tert-butyl alcohol along with other organic compounds. Here, we report the draft genome sequence of M. sp. strain T29 together with the description of the genome properties and its annotation. The draft genome consists of 608 contigs with a total size of 4,449,424 bp and an average coverage of 150×. The genome exhibits an average G + C content of 68.7 %, and contains 4754 protein coding and 52 RNA genes, including 48 tRNA genes. 71 % of the protein coding genes could be assigned to COG (Clusters of Orthologous Groups) categories. A formerly unknown circular plasmid designated as pT29A was isolated and sequenced separately and found to be 86,856 bp long.
Pardinas, Miguel; Mendirichaga, Rodrigo; Budhrani, Gaurav; Garg, Rajan; Rosario, Luis; Rico, Rene; Panos, Anthony; Baier, Horst; Krick, Stefanie
2017-01-01
A 32-year-old man presented with a 10-day history of fever, chills, nausea, vomiting, myalgia, nonproductive cough, and worsening dyspnea after freshwater swimming in the Caribbean 1 week prior to presentation. Shortly after arrival at the hospital, the patient developed severe respiratory distress with massive hemoptysis. Based on serologic workup, he was diagnosed with leptospirosis pulmonary hemorrhage syndrome leading to diffuse alveolar hemorrhage, severe hypoxemic respiratory failure, and multiorgan failure. He received appropriate antibiotic coverage along with hemodynamic support with norepinephrine and vasopressin, mechanical ventilation, and renal replacement therapy in an intensive care unit. Introduction of extracorporeal membrane oxygenation was initiated to provide lung-protective ventilation supporting the recovery of his pulmonary function. Aminocaproic acid was used to stop and prevent further alveolar hemorrhage. He fully recovered thereafter; however, it is uncertain whether it was the use of aminocaproic acid that led to the resolution of his disease.
Pardinas, Miguel; Mendirichaga, Rodrigo; Budhrani, Gaurav; Garg, Rajan; Rosario, Luis; Rico, Rene; Panos, Anthony; Baier, Horst; Krick, Stefanie
2017-01-01
A 32-year-old man presented with a 10-day history of fever, chills, nausea, vomiting, myalgia, nonproductive cough, and worsening dyspnea after freshwater swimming in the Caribbean 1 week prior to presentation. Shortly after arrival at the hospital, the patient developed severe respiratory distress with massive hemoptysis. Based on serologic workup, he was diagnosed with leptospirosis pulmonary hemorrhage syndrome leading to diffuse alveolar hemorrhage, severe hypoxemic respiratory failure, and multiorgan failure. He received appropriate antibiotic coverage along with hemodynamic support with norepinephrine and vasopressin, mechanical ventilation, and renal replacement therapy in an intensive care unit. Introduction of extracorporeal membrane oxygenation was initiated to provide lung-protective ventilation supporting the recovery of his pulmonary function. Aminocaproic acid was used to stop and prevent further alveolar hemorrhage. He fully recovered thereafter; however, it is uncertain whether it was the use of aminocaproic acid that led to the resolution of his disease. PMID:28469503
Surveillance of Vaccination Coverage Among Adult Populations - United States, 2014.
Williams, Walter W; Lu, Peng-Jun; O'Halloran, Alissa; Kim, David K; Grohskopf, Lisa A; Pilishvili, Tamara; Skoff, Tami H; Nelson, Noele P; Harpaz, Rafael; Markowitz, Lauri E; Rodriguez-Lainz, Alfonso; Bridges, Carolyn B
2016-02-05
Overall, the prevalence of illness attributable to vaccine-preventable diseases is greater among adults than among children. Adults are recommended to receive vaccinations based on their age, underlying medical conditions, lifestyle, prior vaccinations, and other considerations. Updated vaccination recommendations from CDC are published annually in the U.S. Adult Immunization Schedule. Despite longstanding recommendations for use of many vaccines, vaccination coverage among U.S. adults is low. August 2013-June 2014 (for influenza vaccination) and January-December 2014 (for pneumococcal, tetanus and diphtheria [Td] and tetanus and diphtheria with acellular pertussis [Tdap], hepatitis A, hepatitis B, herpes zoster, and human papillomavirus [HPV] vaccination). The National Health Interview Survey (NHIS) is a continuous, cross-sectional national household survey of the noninstitutionalized U.S. civilian population. In-person interviews are conducted throughout the year in a probability sample of households, and NHIS data are compiled and released annually. The survey objective is to monitor the health of the U.S. population and provide estimates of health indicators, health care use and access, and health-related behaviors. Compared with data from the 2013 NHIS, increases in vaccination coverage occurred for Tdap vaccine among adults aged ≥19 years (a 2.9 percentage point increase to 20.1%) and herpes zoster vaccine among adults aged ≥60 years (a 3.6 percentage point increase to 27.9%). Aside from these modest improvements, vaccination coverage among adults in 2014 was similar to estimates from 2013 (for influenza coverage, similar to the 2012-13 season). Influenza vaccination coverage among adults aged ≥19 years was 43.2%. Pneumococcal vaccination coverage among high-risk persons aged 19-64 years was 20.3% and among adults aged ≥65 years was 61.3%. Td vaccination coverage among adults aged ≥19 years was 62.2%. Hepatitis A vaccination coverage among adults aged ≥19 years was 9.0%. Hepatitis B vaccination coverage among adults aged ≥19 years was 24.5%. HPV vaccination coverage among adults aged 19-26 years was 40.2% for females and 8.2% for males. Racial/ethnic differences in coverage persisted for all seven vaccines, with higher coverage generally for whites compared with most other groups. Adults without health insurance were significantly less likely than those with health insurance to report receipt of influenza vaccine (aged ≥19 years), pneumococcal vaccine (aged 19-64 years with high-risk conditions and aged ≥65 years), Td vaccine (aged ≥19 years), Tdap vaccine (aged ≥19 years and 19-64 years), hepatitis A vaccine (aged ≥19 years overall and among travelers), hepatitis B vaccine (aged ≥19 years, 19-49 years, and 19-59 years with diabetes), herpes zoster vaccine (aged ≥60 years and 60-64 years), and HPV vaccine (females aged 19-26 years and males aged 19-26 years). Adults who reported having a usual place for health care generally were more likely to receive recommended vaccinations than those who did not have a usual place for health care, regardless of whether they had health insurance. Vaccination coverage was significantly higher among those reporting one or more physician contacts in the past year compared with those who had not visited a physician in the past year, regardless of whether they had health insurance. Even among adults who had health insurance and ≥10 physician contacts within the past year, 23.8%-88.8% reported not having received vaccinations that were recommended either for all persons or for those with some specific indication. Overall, vaccination coverage among U.S.-born respondents was significantly higher than that of foreign-born respondents with few exceptions (influenza vaccination [adults aged 19-49 years], hepatitis A vaccination [adults aged ≥19 years], hepatitis B vaccination [adults with diabetes aged ≥60 years], and HPV vaccination [males aged 19-26 years]). Overall, increases in adult vaccination coverage are needed. Although modest gains occurred in Tdap vaccination coverage among adults aged ≥19 years and herpes zoster vaccination coverage among adults aged ≥60 years, coverage for other vaccines and risk groups did not improve, and racial/ethnic disparities persisted for routinely recommended adult vaccines. Coverage for all vaccines for adults remained low, and missed opportunities to vaccinate adults continued. Although having health insurance coverage and a usual place for health care are associated with higher vaccination coverage, these factors alone do not assure optimal adult vaccination coverage. Assessing associations with vaccination is important for understanding factors that contribute to low coverage rates and to disparities in vaccination, and for implementing strategies to improve vaccination coverage. Practices that have been demonstrated to improve vaccination coverage should be used. These practices include assessment of patients' vaccination indications by health care providers and routine recommendation and offer of needed vaccines to adults, implementation of reminder-recall systems, use of standing-order programs for vaccination, and assessment of practice-level vaccination rates with feedback to staff members. For vaccination to be improved among those least likely to be up-to-date on recommended adult vaccines, efforts also are needed to identify adults who do not have a regular provider or insurance and who report fewer health care visits.
Mao, Bao-Hua; Crumlin, Ethan; Tyo, Eric C.; ...
2016-07-21
In this work, ambient pressure X-ray photoelectron spectroscopy (APXPS) was used to investigate the effect of oxygen adsorption on the band bending and electron affinity of Al 2O 3, ZnO and TiO 2 ultrathin films (~1 nm in thickness) deposited on a Si substrate by atomic layer deposition (ALD). Upon exposure to oxygen at room temperature (RT), upward band bending was observed on all three samples, and a decrease in electron affinity was observed on Al 2O 3 and ZnO ultrathin films at RT. At 80°C, the magnitude of the upward band bending decreased, and the change in the electronmore » affinity vanished. These results indicate the existence of two surface oxygen species: a negatively charged species that is strongly adsorbed and responsible for the observed upward band bending, and a weakly adsorbed species that is polarized, lowering the electron affinity. Based on the extent of upward band bending on the three samples, the surface coverage of the strongly adsorbed species exhibits the following order: Al 2O 3 > ZnO > TiO 2. This finding is in stark contrast to the trend expected on the surface of these bulk oxides, and highlights the unique surface activity of ultrathin oxide films with important implications, for example, in oxidation reactions taking place on these films or in catalyst systems where such oxides are used as a support material.« less
High efficiency multishot interleaved spiral-in/out: acquisition for high-resolution BOLD fMRI.
Jung, Youngkyoo; Samsonov, Alexey A; Liu, Thomas T; Buracas, Giedrius T
2013-08-01
Growing demand for high spatial resolution blood oxygenation level dependent (BOLD) functional magnetic resonance imaging faces a challenge of the spatial resolution versus coverage or temporal resolution tradeoff, which can be addressed by methods that afford increased acquisition efficiency. Spiral acquisition trajectories have been shown to be superior to currently prevalent echo-planar imaging in terms of acquisition efficiency, and high spatial resolution can be achieved by employing multiple-shot spiral acquisition. The interleaved spiral in/out trajectory is preferred over spiral-in due to increased BOLD signal contrast-to-noise ratio (CNR) and higher acquisition efficiency than that of spiral-out or noninterleaved spiral in/out trajectories (Law & Glover. Magn Reson Med 2009; 62:829-834.), but to date applicability of the multishot interleaved spiral in/out for high spatial resolution imaging has not been studied. Herein we propose multishot interleaved spiral in/out acquisition and investigate its applicability for high spatial resolution BOLD functional magnetic resonance imaging. Images reconstructed from interleaved spiral-in and -out trajectories possess artifacts caused by differences in T2 decay, off-resonance, and k-space errors associated with the two trajectories. We analyze the associated errors and demonstrate that application of conjugate phase reconstruction and spectral filtering can substantially mitigate these image artifacts. After applying these processing steps, the multishot interleaved spiral in/out pulse sequence yields high BOLD CNR images at in-plane resolution below 1 × 1 mm while preserving acceptable temporal resolution (4 s) and brain coverage (15 slices of 2 mm thickness). Moreover, this method yields sufficient BOLD CNR at 1.5 mm isotropic resolution for detection of activation in hippocampus associated with cognitive tasks (Stern memory task). The multishot interleaved spiral in/out acquisition is a promising technique for high spatial resolution BOLD functional magnetic resonance imaging applications. © 2012 Wiley Periodicals, Inc.
Kimura, Akiko C; Nguyen, Christine N; Higa, Jeffrey I; Hurwitz, Eric L; Vugia, Duc J
2007-04-01
We examined barriers to influenza vaccination among long-term care facility (LTCF) health care workers in Southern California and developed simple, effective interventions to improve influenza vaccine coverage of these workers. In 2002, health care workers at LTCFs were surveyed regarding their knowledge and attitudes about influenza and the influenza vaccine. Results were used to develop 2 interventions, an educational campaign and Vaccine Day (a well-publicized day for free influenza vaccination of all employees at the worksite). Seventy facilities were recruited to participate in an intervention trial and randomly assigned to 4 study groups. The combination of Vaccine Day and an educational campaign was most effective in increasing vaccine coverage (53% coverage; prevalence ratio [PR]=1.45; 95% confidence interval [CI]=1.24, 1.71, compared with 27% coverage in the control group). Vaccine Day alone was also effective (46% coverage; PR= 1.41; 95% CI=1.17, 1.71). The educational campaign alone was not effective in improving coverage levels (34% coverage; PR=1.18; 95% CI=0.93, 1.50). Influenza vaccine coverage of LTCF health care workers can be improved by providing free vaccinations at the worksite with a well-publicized Vaccine Day.
Wilson, Elizabeth Ruth; Kyle, Theodore K; Nadglowski, Joseph F; Stanford, Fatima Cody
2017-02-01
Evidence-based obesity treatments, such as bariatric surgery, are not considered essential health benefits under the Affordable Care Act. Employer-sponsored wellness programs with incentives based on biometric outcomes are allowed and often used despite mixed evidence regarding their effectiveness. This study examines consumers' perceptions of their coverage for obesity treatments and exposure to workplace wellness programs. A total of 7,378 participants completed an online survey during 2015-2016. Respondents answered questions regarding their health coverage for seven medical services and exposure to employer wellness programs that target weight or body mass index (BMI). Using χ 2 tests, associations between perceptions of exposure to employer wellness programs and coverage for medical services were examined. Differences between survey years were also assessed. Most respondents reported they did not have health coverage for obesity treatments, but more of the respondents with employer wellness programs reported having coverage. Neither the perception of coverage for obesity treatments nor exposure to wellness programs increased between 2015 and 2016. Even when consumers have exposure to employer wellness programs that target BMI, their health insurance often excludes obesity treatments. Given the clinical and cost-effectiveness of such treatments, reducing that coverage gap may mitigate obesity's individual- and population-level effects. © 2017 The Obesity Society.
Massachusetts health reform: employers, lower-wage workers and universal coverage.
Felland, Laurie; Draper, Debra; Liebhaber, Allison
2007-07-01
As Massachusetts' landmark effort to reach nearly universal health coverage unfolds, the state is now focusing on employers to take steps to increase coverage. All employers--except firms with fewer than 11 workers--face new requirements under the 2006 law, including establishing Section 125, or cafeteria, plans to allow workers to purchase insurance with pre-tax dollars and paying a $295 annual fee if they do not make a "fair and reasonable" contribution to the cost of workers' coverage. Through interviews with Massachusetts health care leaders (see Data Source), the Center for Studying Health System Change (HSC) examined how the law is likely to affect employer decisions to offer health insurance to workers and employee decisions to purchase coverage. Market observers believe many small firms may be unaware of specific requirements and that some could prove onerous. Moreover, the largest impact on small employers may come from the individual mandate for all residents to have a minimum level of health insurance. This mandate may add costs for firms if more workers take up coverage offers, seek more generous coverage or pressure employers to offer coverage. Despite reform of the individual and small group markets, including development of new insurance products, concerns remain about the affordability of coverage and the ability to stem rising health care costs.
Increasing malaria hospital admissions in Uganda between 1999 and 2009
2011-01-01
Background Some areas of Africa are witnessing a malaria transition, in part due to escalated international donor support and intervention coverage. Areas where declining malaria rates have been observed are largely characterized by relatively low baseline transmission intensity and rapid scaling of interventions. Less well described are changing patterns of malaria burden in areas of high parasite transmission and slower increases in control and treatment access. Methods Uganda is a country predominantly characterized by intense, perennial malaria transmission. Monthly pediatric admission data from five Ugandan hospitals and their catchments have been assembled retrospectively across 11 years from January 1999 to December 2009. Malaria admission rates adjusted for changes in population density within defined catchment areas were computed across three time periods that correspond to periods where intervention coverage data exist and different treatment and prevention policies were operational. Time series models were developed adjusting for variations in rainfall and hospital use to examine changes in malaria hospitalization over 132 months. The temporal changes in factors that might explain changes in disease incidence were qualitatively examined sequentially for each hospital setting and compared between hospital settings Results In four out of five sites there was a significant increase in malaria admission rates. Results from time series models indicate a significant month-to-month increase in the mean malaria admission rates at four hospitals (trend P < 0.001). At all hospitals malaria admissions had increased from 1999 by 47% to 350%. Observed changes in intervention coverage within the catchments of each hospital showed a change in insecticide-treated net coverage from <1% in 2000 to 33% by 2009 but accompanied by increases in access to nationally recommended drugs at only two of the five hospital areas studied. Conclusions The declining malaria disease burden in some parts of Africa is not a universal phenomena across the continent. Despite moderate increases in the coverage of measures to reduce infection and disease without significant coincidental increasing access to effective medicines to treat disease may not lead to severe disease burden reductions in high transmission areas of Africa. More data is needed from a wider range of malaria settings to provide an honest tracking progress of the impact of scaled intervention coverage in Africa. PMID:21486498
Ward, Charlotte; Byrne, Lisa; White, Joanne M; Amirthalingam, Gayatri; Tiley, Karen; Edelstein, Michael
2017-04-25
In September 2013, England introduced a shingles vaccination programme to reduce incidence and severity of shingles in the elderly. This study aims to assess variation in vaccine coverage with regards to selected sociodemographic factors to inform activities for improving equity of the programme. Eligible 70year-olds were identified from a national vaccine coverage dataset in 2014/15 that includes 95% of GPs in England. NHS England Local Team (LT) and index of multiple deprivation (IMD) scores were assigned to patients based on GP-postcode. Vaccine coverage (%) with 95% confidence intervals (CIs), were calculated overall and by LT, ethnicity and IMD, using binomial regression. Of 502,058 eligible adults, 178,808 (35.6%) had ethnicity recorded. Crude vaccine coverage was 59.5% (95%CI: 59.3-59.7). Coverage was lowest in London (49.6% coverage, 95%CI: 49.0-50.2), and compared to this coverage was significantly higher in all other LTs (+6.3 to +10.4, p<0.001) after adjusting for ethnicity and IMD. Coverage decreased with increasing deprivation and was 8.2% lower in the most deprived (95%CI: 7.3-9.1) compared with the least deprived IMD quintile (64.1% coverage, 95%CI: 63.6-64.6), after adjustment for ethnicity and LT. Compared with White-British (60.7% coverage, 95%CI: 60.5-61.0), other ethnic groups had between 4.0% (Indian) and 21.8% (Mixed: White and Black African) lower coverage. After adjusting for IMD and LT, significantly lower coverage by ethnicity persisted in all groups, except in Mixed: Other, Indian and Bangladeshi compared with White-British. After taking geography and deprivation into account, shingles vaccine coverage varied by ethnicity. White-British, Indian and Bangladeshi groups had highest coverage; Mixed: White and Black African, and Black-other ethnicities had the lowest. Patients' ethnicity and IMD are predictors of coverage which contribute to, but do not wholly account for, geographical variation coverage. Interventions to address service-related, sociodemographic and ethnic inequalities in shingles vaccine coverage are required. Copyright © 2017 Elsevier Ltd. All rights reserved.
Simulation of Flow Fluid in the BOF Steelmaking Process
NASA Astrophysics Data System (ADS)
Lv, Ming; Zhu, Rong; Guo, Ya-Guang; Wang, Yong-Wei
2013-12-01
The basic oxygen furnace (BOF) smelting process consists of different chemical reactions among oxygen, slag, and molten steel, which engenders a vigorous stirring process to promote slagging, dephosphorization, decarbonization, heating of molten steel, and homogenization of steel composition and temperature. Therefore, the oxygen flow rate, lance height, and slag thickness vary during the smelting process. This simulation demonstrated a three-dimensional mathematical model for a 100 t converter applying four-hole supersonic oxygen lance and simulated the effect of oxygen flow rate, lance height, and slag thickness on the flow of molten bath. It is found that as the oxygen flow rate increases, the impact area and depth increases, which increases the flow speed in the molten bath and decreases the area of dead zone. Low oxygen lance height benefits the increase of impact depth and accelerates the flow speed of liquid steel on the surface of the bath, while high oxygen lance height benefits the increase of impact area, thereafter enhances the uniform distribution of radial velocity in the molten steel and increases the flow velocity of molten steel at the bottom of furnace hearth. As the slag thickness increases, the diameter of impinging cavity on the slag and steel surface decreases. The radial velocity of liquid steel in the molten bath is well distributed when the jet flow impact on the slag layer increases.
DiGiulio, Anne; Haddix, Meredith; Jump, Zach; Babb, Stephen; Schecter, Anna; Williams, Kisha-Ann S; Asman, Kat; Armour, Brian S
2016-12-09
In 2015, 27.8% of adult Medicaid enrollees were current cigarette smokers, compared with 11.1% of adults with private health insurance, placing Medicaid enrollees at increased risk for smoking-related disease and death (1). In addition, smoking-related diseases are a major contributor to Medicaid costs, accounting for about 15% (>$39 billion) of annual Medicaid spending during 2006-2010 (2). Individual, group, and telephone counseling and seven Food and Drug Administration (FDA)-approved medications are effective treatments for helping tobacco users quit (3). Insurance coverage for tobacco cessation treatments is associated with increased quit attempts, use of cessation treatments, and successful smoking cessation (3); this coverage has the potential to reduce Medicaid costs (4). However, barriers such as requiring copayments and prior authorization for treatment can impede access to cessation treatments (3,5). As of July 1, 2016, 32 states (including the District of Columbia) have expanded Medicaid eligibility through the Patient Protection and Affordable Care Act (ACA),* ,† which has increased access to health care services, including cessation treatments (5). CDC used data from the Centers for Medicare and Medicaid Services (CMS) Medicaid Budget and Expenditure System (MBES) and the Behavioral Risk Factor Surveillance System (BRFSS) to estimate the number of adult smokers enrolled in Medicaid expansion coverage. To assess cessation coverage among Medicaid expansion enrollees, the American Lung Association collected data on coverage of, and barriers to accessing, evidence-based cessation treatments. As of December 2015, approximately 2.3 million adult smokers were newly enrolled in Medicaid because of Medicaid expansion. As of July 1, 2016, all 32 states that have expanded Medicaid eligibility under ACA covered some cessation treatments for all Medicaid expansion enrollees, with nine states covering all nine cessation treatments for all Medicaid expansion enrollees. All 32 states imposed one or more barriers on at least one cessation treatment for at least some enrollees. Providing barrier-free access to cessation treatments and promoting their use can increase use of these treatments and reduce smoking and smoking-related disease, death, and health care costs among Medicaid enrollees (4,6-8).
“Aging Out” of Dependent Coverage and the Effects on US Labor Market and Health Insurance Choices
2015-01-01
Objectives. I examined how labor market and health insurance outcomes were affected by the loss of dependent coverage eligibility under the Patient Protection and Affordable Care Act (ACA). Methods. I used National Health Interview Survey (NHIS) data and regression discontinuity models to measure the percentage-point change in labor market and health insurance outcomes at age 26 years. My sample was restricted to unmarried individuals aged 24 to 28 years and to a period of time before the ACA’s individual mandate (2011–2013). I ran models separately for men and women to determine if there were differences based on gender. Results. Aging out of this provision increased employment among men, employer-sponsored health insurance offers for women, and reports that health insurance coverage was worse than it was 1 year previously (overall and for young women). Uninsured rates did not increase at age 26 years, but there was an increase in the purchase of non–group health coverage, indicating interest in remaining insured after age 26 years. Conclusions. Many young adults will turn to state and federal health insurance marketplaces for information about health coverage. Because young adults (aged 18–29 years) regularly use social media sites, these sites could be used to advertise insurance to individuals reaching their 26th birthdays. PMID:26447916
Ahanhanzo, Y Glèlè; Palenfo, D; Saussier, C; Gbèdonou, P; Tonda, A; Da Silva, A; Aplogan, A
2016-08-01
Within the framework of its strategic goal of vaccine coverage (VC) improvement, GAVI, The Vaccine Alliance has entrusted the Agence de médecine préventive (agency for preventive medicine, AMP) with technical assistance services to Cameroon, Cote d'Ivoire (Ivory Coast), and Mauritania. This support was provided to selected priority districts (PDs) with the worst Penta3 coverage performances. In 2014, PDs benefited from technical and management capacities in vaccinology strengthening for district medical officers, supportive supervisions and technical assistance in health logistics, data management and quality. We analyzed the effects of the AMP technical assistance on the improvement of the cumulative Penta3 coverage, which is the key performance indicator of the expanded programme on immunization (EPI) performance. We compared Penta3 coverage between PDs and other non-priority districts (NPDs), Penta3 coverage evolution within each PD, and the distribution of PDs and NPDs according to Penta3 coverage category between January and December 2014. Technical assistance had a positive effect on the EPI performance. Indeed Penta3 coverage progression was higher in PDs than in NPDs throughout the period. Besides, between January and December 2014, the Penta3 VC increased in 70%, 100% and 86% of DPs in Cameroon, Côte d'Ivoire and Mauritania, respectively. Furthermore, the increase in the number of PDs with a Penta3 coverage over 80% was higher in DPs than in NPDs: 20% versus 8% for Cameroon, 58% versus 29% for Côte d'Ivoire and 17% versus 8% for Mauritania. Despite positive and encouraging results, this technical assistance service can be improved and efforts are needed to ensure that all health districts have a VC above 80% for all EPI vaccines. The current challenge is for African countries to mobilize resources for maintaining the knowledge and benefits and scaling such interventions in the public health area.
Near-Limit Flamelet Phenomena in Buoyant Low Stretch Diffusion Flames Beneath a Solid Fuel
NASA Technical Reports Server (NTRS)
Olson, S. L.; Tien, J. S.
2000-01-01
A unique near-limit low stretch multidimensional stable flamelet phenomena has been observed for the first time which extends the material flammability limit beyond the one-dimensional low stretch flammability limit to lower burning rates and higher relative heat losses than is possible with uniform flame coverage. During low stretch experiments burning the underside of very large radii (greater than or = 75 cm stretch rate less than or = 3/s) cylindrical cast PMMA samples, multidimensional flamelets were observed, in contrast with a one-dimensional flame that was found to blanket the surface for smaller radii samples ( higher stretch rate). Flamelets were observed by decreasing the stretch rate or by increasing the conductive heat loss from the flame. Flamelets are defined as flames that cover only part of the burning sample at any given time, but persist for many minutes. Flamelet phenomena is viewed as the flame's method of enhancing oxygen flow to the flame, through oxygen transport into the edges of the flamelet. Flamelets form as heat losses (surface radiation and solid-phase conduction) become large relative to the weakened heat release of the low stretch flame. While heat loss rates remain fairly constant, the limiting factor in the heat release of the flame is hypothesized to be the oxygen transport to the flame in this low stretch (low convective) environment. Flamelet extinction is frequently caused by encroachment of an adjacent flamelet. Large-scale whole-body flamelet oscillations at 1.2 - 1.95 Hz are noted prior to extinction of a flamelet. This oscillation is believed to be due a repeated process of excess fuel leakage through the dark channels between the flamelets, fuel premixing with slow incoming oxidizer, and subsequent rapid flame spread and retreat of the flamelet through the premixed layer. The oscillation frequency is driven by gas-phase diffusive time scales.
Hong, Qingshui; Lu, Huimin
2017-06-13
Carbon fiber papers supported Ag catalysts (Ag/CFP) with different coverage of electro-active site are prepared by electrochemical deposition and used as binder free cathodes in primary aluminum-air (Al-air) battery. Scanning Electron Microscopy and X-ray Diffraction studies are carried out to characterize the as-prepared Ag/CFP air cathodes. Oxygen reduction reaction (ORR) activities on these air cathodes in alkaline solutions are systematic studied. A newly designed aluminum-air cell is used to further determine the cathodes performance under real operation condition and during the test, the Ag/CFP electrodes show outstanding catalytic activity for ORR in concentrated alkaline electrolyte, and no obvious activity degradation is observed after long-time discharge. The electrochemical test results display the dependence of coverage of the electro-active Ag on the catalytic performance of the air cathodes. The resulting primary Al-air battery made from the best-performing cathode shows an impressive discharge peak power density, outperforming that of using commercial nano-manganese catalyst air electrodes.
Kenmoe, Stephane; Lisovski, Oleg; Piskunov, Sergei; Bocharov, Dmitry; Zhukovskii, Yuri F; Spohr, Eckhard
2018-05-31
We use ab initio molecular dynamics simulations to study the adsorption of thin water films with 1 and 2 ML coverage on anatase TiO 2 (001) nanotubes. The nanotubes are modeled as 2D slabs, which consist of partially constrained and partially relaxed structural motifs from nanotubes. The effect of anion doping on the adsorption is investigated by substituting O atoms with N and S impurities on the nanotube slab surface. Due to strain-induced curvature effects, water adsorbs molecularly on defect-free surfaces via weak bonds on Ti sites and H bonds to surface oxygens. While the introduction of an S atom weakens the interaction of the surface with water, which adsorbs molecularly, the presence of an N impurity renders the surface more reactive to water, with a proton transfer from the water film and the formation of an NH group at the N site. At 2 ML coverage, a further surface-assisted proton transfer takes place in the water film, resulting in the formation of an OH - group and an NH 2 + cationic site on the surface.
NASA Astrophysics Data System (ADS)
Bitzer, T.; Richardson, N. V.; Reiss, S.; Wühn, M.; Wöll, Ch.
2000-06-01
The structure of benzoate on Na/Si(100)-2×1 has been studied by high resolution electron energy loss spectroscopy, X-ray photoelectron spectroscopy and near edge X-ray adsorption fine structure spectroscopy. At room temperature, benzoic acid (C 6H 5COOH) chemisorbs on Na/Si(100)-2×1 through a cleavage of the OH bond in the carboxylic group. The benzoate molecules formed are bonded exclusively to the sodium atoms in a bidentate coordination, in which the oxygen atoms are equivalent. At room temperature, benzoate saturation on Na/Si(100)-2×1 is reached at a coverage of one benzoate species for each Na atom or silicon dimer. At this coverage, the molecules are tilted in polar direction by 62°±4° to the surface plane and azimuthally rotated by 41°±4° with respect to the [01 1] surface azimuth. We propose an adsorbate structure, in which the benzoate molecules are oriented parallel to each other in densely packed rows.
Medicare is scrutinizing evidence more tightly for national coverage determinations.
Chambers, James D; Chenoweth, Matthew; Cangelosi, Michael J; Pyo, Junhee; Cohen, Joshua T; Neumann, Peter J
2015-02-01
We examined Medicare national coverage determinations for medical interventions to determine whether or not they have become more restrictive over time. National coverage determinations address whether particular big-ticket medical items, services, treatment procedures, and technologies can be paid for under Medicare. We found that after we adjusted for the strength of evidence and other factors known to influence the determinations of the Centers for Medicare and Medicaid Services (CMS), the evidentiary bar for coverage has risen. More recent coverage determinations (from mid-March 2008 through August 2012) were twenty times less likely to be positive than earlier coverage determinations (from February 1999 through January 2002). Furthermore, coverage during the study period was increasingly and positively associated both with the degree of consistency of favorable findings in the CMS reviewed clinical evidence and with recommendations made in clinical guidelines. Coverage policy is an important payer tool for promoting the appropriate use of medical interventions, but CMS's rising evidence standards also raise questions about patients' access to new technologies and about hurdles for the pharmaceutical and device industries as they attempt to bring innovations to the market. Project HOPE—The People-to-People Health Foundation, Inc.
Larsen, David A; Borrill, Lauren; Patel, Ryan; Fregosi, Lauren
2017-06-13
Malaria is an important cause of morbidity and mortality in malaria-endemic areas. Indoor residual spray is an effective intervention to control malaria, but high community-level coverage is needed to maximize its impact. Using thirty-four two-stage cluster surveys (e.g., demographic and health surveys) and lot quality assurance sampling, indoor residual spray was estimated at the community level (i.e. enumeration-area) across sub-Saharan Africa since 2010. For communities receiving indoor residual spray a logistic regression predicted whether community-level coverage exceeded 50% or not. Household-level coverage was equitable both in terms of wealth and urban/rural, with poorer and rural houses more likely to be sprayed than richer and urban houses. Coverage of indoor residual spray at the community level is poor across the continent, with 54% of communities receiving the intervention not reaching 50% coverage. Having >50% coverage at the community-level was not associated with increasing the number of houses sprayed in the country. Implementation and monitoring of indoor residual coverage at small geographical scales need to improve greatly to receive maximum benefit of the intervention.
NASA Astrophysics Data System (ADS)
Dong, L.; Jiang, H.; Yang, L.
2018-04-01
Based on the Landsat images in 2006, 2011 and 2015, and the method of dimidiate pixel model, the Normalized Difference Vegetation Index (NDVI) and the vegetation coverage, this paper analyzes the spatio-temporal variation of vegetation coverage in Changchun, China from 2006 to 2015, and investigates the response of vegetation coverage change to natural and artificial factors. The research results show that in nearly 10 years, the vegetation coverage in Changchun dropped remarkably, and reached the minimum in 2011. Moreover, the decrease of maximum NDVI was significant, with a decrease of about 27.43 %, from 2006 to 2015. The vegetation coverage change in different regions of the research area was significantly different. Among them, the vegetation change in Changchun showed a little drop, and it decreased firstly and then increased slowly in Yushu, Nong'an and Dehui. In addition, the temperature and precipitation change, land reclamation all affect the vegetation coverage. In short, the study of vegetation coverage change contributes scientific and technical support to government and environmental protection department, so as to promote the coordinated development of ecology and economy.
Incentives for nondiscriminatory wellness programs in group health plans. Final rule.
2013-06-03
This document contains final regulations, consistent with the Affordable Care Act, regarding nondiscriminatory wellness programs in group health coverage. Specifically, these final regulations increase the maximum permissible reward under a health-contingent wellness program offered in connection with a group health plan (and any related health insurance coverage) from 20 percent to 30 percent of the cost of coverage. The final regulations further increase the maximum permissible reward to 50 percent for wellness programs designed to prevent or reduce tobacco use. These regulations also include other clarifications regarding the reasonable design of health-contingent wellness programs and the reasonable alternatives they must offer in order to avoid prohibited discrimination.
Workers on the margin: who drops health coverage when prices rise?
Okeke, Edward N; Hirth, Richard A; Grazier, Kyle
2010-01-01
We revisit the question of price elasticity of employer-sponsored insurance (ESI) take-up by directly examining changes in the take-up of ESI at a large firm in response to exogenous changes in employee premium contributions. We find that, on average, a 10% increase in the employee's out-of-pocket premium increases the probability of dropping coverage by approximately 1%. More importantly, we find heterogeneous impacts: married workers are much more price-sensitive than single employees, and lower-paid workers are disproportionately more likely to drop coverage than higher-paid workers. Elasticity estimates for employees below the 25th percentile of salary distribution in our sample are nearly twice the average.
Health Reform and Utilization of High-Volume Hospitals for Complex Cancer Operations.
Loehrer, Andrew P; Chang, David C; Song, Zirui; Chang, George J
2018-01-01
Underinsured patients are less likely to receive complex cancer operations at hospitals with high surgical volumes (high-volume hospitals, or HVHs), which contributes to disparities in care. To date, the impact of insurance coverage expansion on site of complex cancer surgery remains unknown. Using the 2006 Massachusetts coverage expansion as a natural experiment, we searched the Hospital Cost and Utilization Project state inpatient databases for Massachusetts and control states (New York, New Jersey, and Florida) between 2001 and 2011 to evaluate changes in the utilization of HVHs for resections of bladder, esophageal, stomach, pancreatic, rectal, or lung cancer after the expansion of insurance coverage. We studied nonelderly, adult patients with private insurance and those with government-subsidized or self-pay (GSSP) coverage with a difference-in-differences framework. We studied 11,687 patients in Massachusetts and 56,300 patients in control states. Compared with control states, the 2006 Massachusetts insurance expansion was associated with a 14% increased rate of surgical intervention for GSSP patients (incident rate ratio, 1.14; P = .015), but there was no significant change in the probability of GSSP patients undergoing surgery at an HVH (1.0 percentage-point increase; P = .710). The reform was associated with no change in the uninsured payer-mix at HVHs (0.6 percentage-point increase; P = .244) and with a 5.1 percentage-point decrease for the uninsured payer mix at low-volume hospitals ( P < .001). The 2006 Massachusetts insurance expansion, a model for the Affordable Care Act, was associated with increased rates of complex cancer operations and increased insurance coverage but with no change in utilization of HVH for complex cancer operations.
The growth in newspaper coverage of tobacco control in China, 2000-2010.
Gao, Junling; Chapman, Simon; Sun, Shaojing; Fu, Hua; Zheng, Pinpin
2012-03-07
Media coverage of tobacco-related issues can potentially shape individual beliefs, attitudes and behaviors about tobacco use. This study aims to describe news coverage of tobacco control related issues in Chinese newspapers from 2000 to 2010. All 1149 articles related to tobacco control were extracted from the Database of Chinese Important Newspapers and content analyzed for the period Jan 1, 2000 to Dec 31, 2010. The changing pattern of tobacco control topic, article type, viewpoint, and article origin, and their relationship were analysed. News coverage of tobacco control related issues increased significantly (p < 0.01) from 2000 to 2010, with news coverage being relatively intensive in May and June (p < 0.01), around World No Tobacco Day. 24.9% (n = 286) of all articles focused on secondhand smoke, 25.3% (n = 291) warned about the dangers of active smoking, and 10.0% (n = 115) focused on prevention and cessation programs and campaigns. Tobacco control topics varied significantly between national vs city/regional newspapers (χ2 = 24.09, p = 0.002) and article types (χ2 = 193.35, p < 0.001). Articles in national newspapers had more coverage of the dangers of tobacco and on enforcing bans on tobacco-advertising. News stories centered around monitoring tobacco use and smoke free activity, while editorials focused on enforcing bans on tobacco-advertising, youth access and programs and campaigns. Letters to editors focused on the dangers of smoking, raising tax, and smoking cessation. More articles (50.4%) took an anti-tobacco position (compared with 10.5% which were pro-smoking), with the amount of negative coverage growing significantly across the decade. National articles tended to lean toward anti-tobacco, however, local articles tended mix of pro-tobacco and neutral/balance positions. Editorials seemed to be more anti-tobacco oriented, but letters to the editor tended to show a mix of anti-tobacco and pro-tobacco positions. Chinese newspapers are giving increasing attention to tobacco control, but coverage remains lower than in the USA and Australia. Health workers need to give higher priority to efforts to increase news coverage beyond the present concentration around World No Tobacco Day and to develop strategies for making tobacco control issues more newsworthy to both national and local news outlets.
Changes in health insurance coverage during the economic downturn: 2000-2002.
Holahan, John; Wang, Marie
2004-01-01
Using Current Population Survey data from 2000-2002, this paper documents the changes that led the uninsured population to grow by 3.8 million during that time period. All of the increase in the uninsured occurred among adults, and two-thirds was among low-income adults. The extent to which the loss of employer coverage resulted in people becoming uninsured depended on their access to public programs: Children were more likely than adults to gain public coverage; women more likely than men; and parents more likely than nonparents. Middle- and higher-income Americans were also affected because many lost income and because rates of employer coverage were lower.
Palkovits, Stefan; Lasta, Michael; Told, Reinhard; Schmidl, Doreen; Werkmeister, René; Cherecheanu, Alina Popa; Garhöfer, Gerhard; Schmetterer, Leopold
2015-01-01
Cerebral and retinal blood flow are dependent on local neuronal activity. Several studies quantified the increase in cerebral blood flow and oxygen consumption during activity. In the present study we investigated the relation between changes in retinal blood flow and oxygen extraction during stimulation with diffuse luminance flicker and the influence of breathing gas mixtures with different fractions of O2 (FiO2; 100% 15% and 12%). Twenty-four healthy subjects were included. Retinal blood flow was studied by combining measurement of vessel diameters using the Dynamic Vessel Analyser with measurements of blood velocity using laser Doppler velocimetry. Oxygen saturation was measured using spectroscopic reflectometry and oxygen extraction was calculated. Flicker stimulation increased retinal blood flow (57.7 ± 17.8%) and oxygen extraction (34.6 ± 24.1%; p < 0.001 each). During 100% oxygen breathing the response of retinal blood flow and oxygen extraction was increased (p < 0.01 each). By contrast, breathing gas mixtures with 12% and 15% FiO2 did not alter flicker–induced retinal haemodynamic changes. The present study indicates that at a comparable increase in blood flow the increase in oxygen extraction in the retina is larger than in the brain. During systemic hyperoxia the blood flow and oxygen extraction responses to neural stimulation are augmented. The underlying mechanism is unknown. PMID:26672758
The adsorption and reactions of the amino acid proline on rutile TiO 2(1 1 0) surfaces
NASA Astrophysics Data System (ADS)
Fleming, G. J.; Adib, K.; Rodriguez, J. A.; Barteau, M. A.; White, J. M.; Idriss, H.
2008-06-01
The reaction of the amino acid DL-proline is studied over stoichiometric and Ar-ions sputtered (reduced) TiO 2(1 1 0) single crystal surfaces by synchrotron High Resolution X-ray Photoelectron Spectroscopy (HRXPS). On the stoichiometric surface proline gives two different species at 300 K: dissociated and zwitterionic. Upon heating the zwitterionic structure is removed first from the surface followed by the dissociated form. The C1s signal for the COO function is found close to 288.5 eV for both forms while the N 1s for the dissociated form is found at 400.0 eV and that of the zwitterionic from close to 401.8 eV. From the attenuation of the Ti 2p signal the surface coverage was estimated less than ½ (about 0.35). This smaller coverage than dissociatively adsorbed carboxylic acids on this surface (usually close to ½), is attributed to lateral repulsion caused by the ring of adjacent proline molecules adsorbed on five-fold coordinated Ti cations along the [0 0 1] direction. On the reduced surface the amount of zwitterion structure is found two times higher than that on the stoichiometric surface, at 300 K, most likely due to the considerable decrease of the amount of surface oxygen available. The stability of the zwitterionic structure on this surface is however found similar to that found on the stoichiometric surface. In addition, evidence of oxidation of reduced Ti cations upon adsorption at 300 K is noticed and explained as breaking of the carbon-oxygen bond of a fraction of adsorbed proline. Variable temperature HRXPS has been collected and results indicated that proline is more stable on the reduced surface compared to the stoichiometric surface.
Enzymatic glucose sensor compensation for variations in ambient oxygen concentration
NASA Astrophysics Data System (ADS)
Collier, Bradley B.; McShane, Michael J.
2013-02-01
Due to the increasing prevalence of diabetes, research toward painless glucose sensing continues. Oxygen sensitive phosphors with glucose oxidase (GOx) can be used to determine glucose levels indirectly by monitoring oxygen consumption. This is an attractive combination because of its speed and specificity. Packaging these molecules together in "smart materials" for implantation will enable non-invasive glucose monitoring. As glucose levels increase, oxygen levels decrease; consequently, the luminescence intensity and lifetime of the phosphor increase. Although the response of the sensor is dependent on glucose concentration, the ambient oxygen concentration also plays a key role. This could lead to inaccurate glucose readings and increase the risk of hyper- or hypoglycemia. To mitigate this risk, the dependence of hydrogel glucose sensor response on oxygen levels was investigated and compensation methods explored. Sensors were calibrated at different oxygen concentrations using a single generic logistic equation, such that trends in oxygen-dependence were determined as varying parameters in the equation. Each parameter was found to be a function of oxygen concentration, such that the correct glucose calibration equation can be calculated if the oxygen level is known. Accuracy of compensation will be determined by developing an overall calibration, using both glucose and oxygen sensors in parallel, correcting for oxygen fluctuations in real time by intentionally varying oxygen, and calculating the error in actual and predicted glucose levels. While this method was developed for compensation of enzymatic glucose sensors, in principle it can also be implemented with other kinds of sensors utilizing oxidases.
Impacts of field of view configuration of Cross-track Infrared Sounder on clear-sky observations.
Wang, Likun; Chen, Yong; Han, Yong
2016-09-01
Hyperspectral infrared radiance measurements from satellite sensors contain valuable information on atmospheric temperature and humidity profiles and greenhouse gases, and therefore are directly assimilated into numerical weather prediction (NWP) models as inputs for weather forecasting. However, data assimilations in current operational NWP models still mainly rely on cloud-free observations due to the challenge of simulating cloud-contaminated radiances when using hyperspectral radiances. The limited spatial coverage of the 3×3 field of views (FOVs) in one field of regard (FOR) (i.e., spatial gap among FOVs) as well as relatively large footprint size (14 km) in current Cross-track Infrared Sounder (CrIS) instruments limits the amount of clear-sky observations. This study explores the potential impacts of future CrIS FOV configuration (including FOV size and spatial coverage) on the amount of clear-sky observations by simulation experiments. The radiance measurements and cloud mask products (VCM) from the Visible Infrared Imager Radiometer Suite (VIIRS) are used to simulate CrIS clear-sky observation under different FOV configurations. The results indicate that, given the same FOV coverage (e.g., 3×3), the percentage of clear-sky FOVs and the percentage of clear-sky FORs (that contain at least one clear-sky FOV) both increase as the FOV size decreases. In particular, if the CrIS FOV size were reduced from 14 km to 7 km, the percentage of clear-sky FOVs increases from 9.02% to 13.51% and the percentage of clear-sky FORs increases from 18.24% to 27.51%. Given the same FOV size but with increasing FOV coverage in each FOR, the clear-sky FOV observations increases proportionally with the increasing sampling FOVs. Both reducing FOV size and increasing FOV coverage can result in more clear-sky FORs, which benefit data utilization of NWP data assimilation.
[Therapeutic factors affecting the healing process in patients with gangrene of the perineum].
Baraket, Oussama; Triki, Wissem; Ayed, Karim; Hmida, Sonia Ben; Lahmidi, Mohamed Amine; Baccar, Abdelamjid; Bouchoucha, Samy
2018-01-01
Fournier gangrene is a rare and severe necrotizing fasciitis. It is burdened with high morbi-mortality, requiring early and massive medical and surgical management. Initial treatment is based on patient's resuscitation associated with surgical debridement. Subsequently, the main challenge is the healing process and its possible sequelae. Several therapeutic approaches are currently available to improve and accelerate the healing process. We conducted a retrospective study of 20 cases. The median age of our patients was 56 years. The study included 16 men and 7 women. Comorbidity was present in 15 patients. Antibiotic therapy was administered in all cases, with a median duration of 15 days. All patients underwent surgery. Iterative reviews were necessary in all patients, who needed, on average, 3 dressing changes. Colostomy was performed in 6 cases. Hyperbaric oxygen therapy was performed in 4 cases. Vacuum assisted closure was performed in 1 case. Soft tissue coverage was necessary in 2 cases. The mean duration of healing was 15 days with oxygen therapy versus 24 days in the absence of this treatment. The mean duration of hospitalization was 20 days. Four patients died. Healing process without sequelae is a therapeutic challenge. Despite the addition of new therapeutic approaches, outcomes are not satisfactory. However, multidisciplinary approach associated with oxygen therapy and vacuum assisted closure might improve patients outcomes.
McIntyre, Di; Ataguba, John E
2012-03-01
South Africa is considering introducing a universal health care system. A key concern for policy-makers and the general public is whether or not this reform is affordable. Modelling the resource and revenue generation requirements of alternative reform options is critical to inform decision-making. This paper considers three reform scenarios: universal coverage funded by increased allocations to health from general tax and additional dedicated taxes; an alternative reform option of extending private health insurance coverage to all formal sector workers and their dependents with the remainder using tax-funded services; and maintaining the status quo. Each scenario was modelled over a 15-year period using a spreadsheet model. Statistical analyses were also undertaken to evaluate the impact of options on the distribution of health care financing burden and benefits from using health services across socio-economic groups. Universal coverage would result in total health care spending levels equivalent to 8.6% of gross domestic product (GDP), which is comparable to current spending levels. It is lower than the status quo option (9.5% of GDP) and far lower than the option of expanding private insurance cover (over 13% of GDP). However, public funding of health services would have to increase substantially. Despite this, universal coverage would result in the most progressive financing system if the additional public funding requirements are generated through a surcharge on taxable income (but not if VAT is increased). The extended private insurance scheme option would be the least progressive and would impose a very high payment burden; total health care payments on average would be 10.7% of household consumption expenditure compared with the universal coverage (6.7%) and status quo (7.5%) options. The least pro-rich distribution of service benefits would be achieved under universal coverage. Universal coverage is affordable and would promote health system equity, but needs careful design to ensure its long-term sustainability.
Kahende, Jennifer; Malarcher, Ann; England, Lucinda; Zhang, Lei; Mowery, Paul; Xu, Xin; Sevilimedu, Varadan; Rolle, Italia
2017-01-01
To assess state coverage and utilization of Medicaid smoking cessation medication benefits among fee-for-service enrollees who smoked cigarettes. We used the linked National Health Interview Survey (survey years 1995, 1997-2005) and the Medicaid Analytic eXtract files (1999-2008) to assess utilization of smoking cessation medication benefits among 5,982 cigarette smokers aged 18-64 years enrolled in Medicaid fee-for-service whose state Medicaid insurance covered at least one cessation medication. We excluded visits during pregnancy, and those covered by managed care or under dual enrollment (Medicaid and Medicare). Multivariate logistic regression was used to determine correlates of cessation medication benefit utilization among Medicaid fee-for-service enrollees, including measures of drug coverage (comprehensive cessation medication coverage, number of medications in state benefit, varenicline coverage), individual-level demographics at NHIS interview, age at Medicaid enrollment, and state-level cigarette excise taxes, statewide smoke-free laws, and per-capita tobacco control funding. In 1999, the percent of smokers with ≥1 medication claims was 5.7% in the 30 states that covered at least one Food and Drug Administration (FDA)-approved cessation medication; this increased to 9.9% in 2008 in the 44 states that covered at least one FDA-approved medication (p<0.01). Cessation medication utilization was greater among older individuals (≥ 25 years), females, non-Hispanic whites, and those with higher educational attainment. Comprehensive coverage, the number of smoking cessation medications covered and varenicline coverage were all positively associated with utilization; cigarette excise tax and per-capita tobacco control funding were also positively associated with utilization. Utilization of medication benefits among fee-for-service Medicaid enrollees increased from 1999-2008 and varied by individual and state-level characteristics. Given that the Affordable Care Act bars state Medicaid programs from excluding any FDA-approved cessation medications from coverage as of January 2014, monitoring Medicaid cessation medication claims may be beneficial for informing efforts to increase utilization and maximize smoking cessation.
Cognition Effects of Low-Grade Hypoxia
2016-07-01
oxygen con- tent and/or cerebral blood flow . Hypocapnia shifts the oxygen dissociation curve to the left, resulting in an increase in blood oxygen ...pressure chamber in a balanced design. Oxygen saturation, heart rate, and cognitive performance on seven different cognitive tasks were measured. In...addition, subjects indicated their symptoms from a 33-item subjective symptom survey. As designed, oxygen saturation decreased and heart rate increased
Wen, Huangding; Li, Zhiqing; Zhang, Meiguang; Wang, Jiahan; Wang, Guifang; Wu, Qi; Tong, Sen
2015-04-01
To evaluate the therapeutic effects of VSD combined with irrigation of oxygen loaded fluid on the growth of granulation tissue and macrophage polarization in chronic venous leg ulcers. Thiry-four patients with chronic venous leg ulcers hospitalized in our department from December 2010 to July 2014 were divided into VSD group ( A, n = 11) , VSD + irrigation group ( B, n = 11) , and VSD + oxygen loaded fluid irrigation group ( C, n = 12) according to the random number table. After admissian, debridement was performed, and granulation tissue in the center of the wound was harvested during the operation. After dehridement, the patients in group A were treated with VSD only (negative pressure from -30 to -25 kPa, the same below) ; the patients in group B were treated with VSD combining irrigation of normal saline; the patients in group C were treated with VSD combining normal saline loaded with oxygen irrigation (flow of 1 L/min) . On post treatment day (PTD) 7, the VSD devices were removed. Cross observation was conducted before debridement and on PTD 7. On PTD 7, the granulation tissue in the center of the wound was harvested for histopathological observation with HE staining and Masson staining, following calculation of granulation tissue coverage rate. After debridement but before the negative pressure therapy (hereinafter referred to as before treatment) and on PTD 7, partial pressure of oxygen of the skin around the wound was measured by transcutaneous tissue oxygen tension survey meter. On PTD 7, expression of vascular endothelial growth factor (VECF) was determined with immunohistochemistry. Before treatment and on PTD 7, cells with double positive expressions of induced nitric oxide synthase plus CD68 ( type I macro- phage) and arginase 1 plus CD68 ( type II macrophage) were observed with immunofluorescence staining and quantified. Data were processed with Fisher's exact test, one-way analysis of variance, covariance analysis, paired test, and LSD test. (1) The gross observation showed that before debridement there was a certain amount of necrotic tissue and little granulation tissue in the wounds of patients in all the 3 groups. On PTD 7, new granulation tissue was found in the wounds of patients in all the 3 groups, and in group C its amount was the largest. (2) On PTD 7, the granulation tissue coverage rate of wounds in pa- tients of group C was higher than that of group A or B ( P <0.05 or P <0.01). (3) On PTD 7, HE staining showed that there appeared more abundant new born microvessels and fibroblasts in the wounds of patients in group C than those in groups A and B; Masson staining showed that there was more abundant fresh collagen distributed orderly in the wounds of patients in group C compared with group A or B. (4) On PTD 7, it was found that partial pressure of oxygen of the skin around the wounds in patients of group C [(40.7 +/- 4.1) mmHg, 1 mmHg = 0.133 kPa] was higher than that of group A [ (35.0 +/- 3.1) mmHg] or B [(35.4 +/- 2.7) mmHg, with P values below 0.01]; the partial pressure of oxygen of the skin around the wounds of patients in all the 3 groups was increased significantly compared with that before treatment (with values from 10.38 to 22.52, P values below 0.01). (5) On PTD 7, the expression of VECF in the wounds of patients in group C was higher than that in group A or B ( P <0.05 or P < 0.01). (6) On PTD 7, the number of type I macrophages in granulation tissue of patients was respectively 14.3 +/- 2.3, 11.5 +/- 3.0, and 10.7 +/- 2.3 per 400 times vision field in groups A , B, and C ( F = 25.14, P < 0.01), while the number in group C was less than that in group A or B ( P < 0.05 or P < 0.01). Compared with that before treatment, the number of type I macrophages was significantly decreased on PTD 7 in all the 3 groups (with values from 14.76 to 23. 73, P values below 0. 01). On PTD 7, the number of type II macrophages in granulation tissue of patients was respectively 32.7 +/- 3.2, 35.1 +/- 3.3 , and 41.3 +/- 3.2 per 400 times vision field in groups A, B, and C ( F = 81.10, P < 0.01), and the number in group C was lager than that in group A or B ( with P values below 0. 01). Compared with that before treatment, the number of type II macrophages in all the 3 groups was significantly increased (with t values from -69.34 to -47.95, P values below 0.01). VSD combined with irrigation of oxygen loaded fluid can raise the partial pressure of oxygen of the skin around the wounds effectively, promoting the transition of macrophages from type I to type II, thus it may promote the growth of granulation tissue, resulting in a better recipient for skin grafting or epithelization.