bluuebunny/crossref_metadata_2025 huggingface dataset:
Social Support: a Key Variable for Health Promotion and Chronic Disease Management in Hispanic Patients with Rheumatic Diseases
Authors: Brooks Alyssa T. , Andrade Regina E. , Middleton Kimberly R. , Wallen Gwenyth R.
Published: March 2014

Chronic diseases, including rheumatic diseases, can cause immense physical and psychosocial burden for patients. Many Hispanics suffering with arthritis face activity limitations. Social support, or the functional content of relationships, may be important to consider when examining treatment and outcomes for Hispanic individuals. Participants were recruited from an urban community health center (CHC) as part of a larger health behavior study. A cross-sectional, descriptive, mixed methods analysis was conducted to explore the role of social support in the sample. Only Hispanic/Latino patients (n = 46) were included in this analysis. Interviews were conducted in both English and Spanish. The majority of the sample (87%) perceived some presence of social support in their lives. The two most commonly cited types of social support were emotional and instrumental. The two most common sources of social support were family members other than spouses (52.2%) and spouses (32.6%). Body mass index (BMI) was significantly correlated with the number of perceived sources of support. The presence or absence and the role of social support in supporting optimal health outcomes should be considered for Hispanics with chronic rheumatic diseases. Involving family members and spouses in the plan of care for this population could facilitate health promotion and chronic disease management.
Cwikel's theorem and the CLR inequality
Authors: Frank Rupert L.
Published: March 2014

We give a short proof of the CLR bound on the number of negative eigenvalues of Schrödinger operators. The argument, which is based on work of Rumin, leads to remarkably good constants and applies to the case of operator-valued potentials as well. Moreover, we obtain the general form of Cwikel's estimate about the singular values of operators of the form

f(X) g(-i\nabla)

.
A priori bounds and existence of non-real eigenvalues of indefinite Sturm–Liouville problems
Authors: Qi Jiangang , Chen Shaozhu
Published: March 2014

The present paper gives a priori bounds on the moduli of the possible non-real eigenvalues to regular indefinite Sturm-Liouville problems and obtains sufficient conditions for such problems to admit non-real eigenvalues.
Quantum ergodicity for a class of mixed systems
Authors: Galkowski Jeffrey
Published: March 2014

We examine high energy eigenfunctions for the Dirichlet Laplacian on domains where the billiard flow exhibits mixed dynamical behavior. (More generally, we consider semiclassical Schrödinger operators with mixed assumptions on the Hamiltonian flow.) Specifically, we assume that the billiard flow has an invariant ergodic component,

U

, and study defect measures,

\mu

, of positive density subsequences of eigenfunctions (and, more generally, of almost orthogonal quasimodes). We show that any defect measure associated to such a subsequence satisfies

\mu|_{U}=c\mu_L|_{U}

, where

\mu_L

is the Liouville measure. This proves part of a conjecture of Percival [18].
Best constants in Lieb-Thirring inequalities: a numerical investigation
Authors: Levitt Antoine
Published: March 2014

We investigate numerically the optimal constants in Lieb–Thirring inequalities by studying the associated maximization problem. Using a monotonic fixed-point algorithm and a finite element discretization, we obtain radial trial potentials which provide lower bounds on the optimal constants. These results confirm existing conjectures, and provide insight into the behavior of the maximizers. Based on our numerical results, we formulate a complete conjecture about the best constants for all possible values of the parameters.
Scattering theory of the $p$-form Laplacian on manifolds with generalized cusps
Authors: Hunsicker Eugenie , Roidos Nikolaos , Strohmaier Alexander
Published: March 2014

In this paper we consider scattering theory on manifolds with special cusp-like metric singularities of warped product type

g=dx^2 + x^{-2 a}h

, where

a>0

. These metrics form a natural subset in the class of metrics with warped product singularities and they can be thought of as interpolating between hyperbolic and cylindrical metrics. We prove that the resolvent of the Laplace operator acting on

p

-forms on such a manifold extends to a meromorphic function defined on the logarithmic cover of the complex plane with values in the bounded operators between weighted

L^2

-spaces. This allows for a construction of generalized eigenforms for the Laplace operator as well as for a meromorphic continuation of the scattering matrix. We give a precise description of the asymptotic expansion of generalized eigenforms on the cusp and find that the scattering matrix satisfies a functional equation.
Study of the unknown HONO daytime source at a European suburban site during the MEGAPOLI summer and winter field campaigns
Authors: Michoud V. , Colomb A. , Borbon A. , Miet K. , Beekmann M. , Camredon M. , Aumont B. , Perrier S. , Zapf P. , Siour G. , Ait-Helal W. , Afif C. , Kukui A. , Furger M. , Dupont J. C. , Haeffelin M. , Doussin J. F.
Published: March 2014

Abstract. Nitrous acid measurements were carried out during the MEGAPOLI summer and winter field campaigns at SIRTA observatory in Paris surroundings. Highly variable HONO levels were observed during the campaigns, ranging from 10 ppt to 500 ppt in summer and from 10 ppt to 1.7 ppb in winter. Significant HONO mixing ratios have also been measured during daytime hours, comprised between some tenth of ppt and 200 ppt for the summer campaign and between few ppt and 1 ppb for the winter campaign. Ancillary measurements, such as NOx, O3, photolysis frequencies, meteorological parameters (pressure, temperature, relative humidity, wind speed and wind direction), black carbon concentration, total aerosol surface area, boundary layer height and soil moisture, were conducted during both campaigns. In addition, for the summer period, OH radical measurements were made with a CIMS (Chemical Ionisation Mass Spectrometer). This large dataset has been used to investigate the HONO budget in a suburban environment. To do so, calculations of HONO concentrations using PhotoStationary State (PSS) approach have been performed, for daytime hours. The comparison of these calculations with measured HONO concentrations revealed an underestimation of the calculations making evident a missing source term for both campaigns. This unknown HONO source exhibits a bell-shaped like average diurnal profile with a maximum around noon of approximately 0.7 ppb h−1 and 0.25 ppb h−1, during summer and winter respectively. This source is the main HONO source during daytime hours for both campaigns. In both cases, this source shows a slight positive correlation with J(NO2) and the product between J(NO2) and soil moisture. This original approach had, thus, indicated that this missing source is photolytic and might be heterogeneous occurring at ground surface and involving water content available on the ground.
Greenhouse gas network design using backward Lagrangian particle dispersion modelling – Part 1: Methodology and Australian test case
Authors: Ziehn T. , Nickless A. , Rayner P. J. , Law R. M. , Roff G. , Fraser P.
Published: March 2014

Abstract. This paper describes the generation of optimal atmospheric measurement networks for determining carbon dioxide fluxes over Australia using inverse methods. A Lagrangian particle dispersion model is used in reverse mode together with a Bayesian inverse modelling framework to calculate the relationship between weekly surface fluxes and hourly concentration observations for the Australian continent. Meteorological driving fields are provided by the regional version of the Australian Community Climate and Earth System Simulator (ACCESS) at 12 km resolution at an hourly time scale. Prior uncertainties are derived on a weekly time scale for biosphere fluxes and fossil fuel emissions from high resolution BIOS2 model runs and from the Fossil Fuel Data Assimilation System (FFDAS), respectively. The influence from outside the modelled domain is investigated, but proves to be negligible for the network design. Existing ground based measurement stations in Australia are assessed in terms of their ability to constrain local flux estimates from the land. We find that the six stations that are currently operational are already able to reduce the uncertainties on surface flux estimates by about 30%. A candidate list of 59 stations is generated based on logistic constraints and an incremental optimization scheme is used to extend the network of existing stations. In order to achieve an uncertainty reduction of about 50% we need to double the number of measurement stations in Australia. Assuming equal data uncertainties for all sites, new stations would be mainly located in the northern and eastern part of the continent.
Fractal properties of forest fires in Amazonia as a basis for modelling pan-tropical burnt area
Authors: Fletcher I. N. , Aragão L. E. O. C. , Lima A. , Shimabukuro Y. , Friedlingstein P.
Published: March 2014

Abstract. Current methods for modelling burnt area in dynamic global vegetation models (DGVMs) involve complex fire spread calculations, which rely on many inputs, including fuel characteristics, wind speed and countless parameters. They are therefore susceptible to large uncertainties through error propagation, but undeniably useful for modelling specific, small-scale burns. Using observed fractal distributions of fire scars in Brazilian Amazonia in 2005, we propose an alternative burnt area model for tropical forests, with fire counts as sole input and few parameters. This model is intended for predicting large-scale burnt area rather than looking at individual fire events. A simple parameterization of a tapered fractal distribution is calibrated at multiple spatial resolutions using a satellite-derived burnt area map. The model is capable of accurately reproducing the total area burnt (16 387 km2) and its spatial distribution. When tested pan-tropically using the MODIS MCD14ML active fire product, the model accurately predicts temporal and spatial fire trends, but the magnitude of the differences between these estimates and the GFED3.1 burnt area products varies per continent.
Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease
Authors: Zhang R. , Duhl T. , Salam M. T. , House J. M. , Flagan R. C. , Avol E. L. , Gilliland F. D. , Guenther A. , Chung S. H. , Lamb B. K. , VanReken T. M.
Published: March 2014

Abstract. Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF/CMAQ) modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation of vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California (USA) for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to underestimate walnut and peak oak pollen concentrations, and tends to overestimate grass pollen concentrations. The model shows reasonable agreement with observed birch, olive, and mulberry tree pollen concentrations. Sensitivity studies suggest that the estimation of the pollen pool is a major source of uncertainty for simulated pollen concentrations. Achieving agreement between emission modeling and observed pattern of pollen releases is the key for successful pollen concentration simulations.
Changing correlation structures of the Northern Hemisphere atmospheric circulation from 1000 to 2100 AD
Authors: Raible C. C. , Lehner F. , González-Rouco J. F. , Fernández-Donado L.
Published: March 2014

Abstract. Atmospheric circulation modes are important concepts in understanding the variability of atmospheric dynamics. Assuming their spatial patterns to be fixed, such modes are often described by simple indices from rather short observational data sets. The increasing length of reanalysis products allows these concepts and assumptions to be scrutinised. Here we investigate the stability of spatial patterns of Northern Hemisphere teleconnections by using the Twentieth Century Reanalysis as well as several control and transient millennium-scale simulations with coupled models. The observed and simulated centre of action of the two major teleconnection patterns, the North Atlantic Oscillation (NAO) and to some extent the Pacific North American (PNA), are not stable in time. The currently observed dipole pattern of the NAO, its centre of action over Iceland and the Azores, split into a north–south dipole pattern in the western Atlantic with a wave train pattern in the eastern part, connecting the British Isles with West Greenland and the eastern Mediterranean during the period 1940–1969 AD. The PNA centres of action over Canada are shifted southwards and over Florida into the Gulf of Mexico during the period 1915–1944 AD. The analysis further shows that shifts in the centres of action of either teleconnection pattern are not related to changes in the external forcing applied in transient simulations of the last millennium. Such shifts in their centres of action are accompanied by changes in the relation of local precipitation and temperature with the overlying atmospheric mode. These findings further undermine the assumption of stationarity between local climate/proxy variability and large-scale dynamics inherent when using proxy-based reconstructions of atmospheric modes, and call for a more robust understanding of atmospheric variability on decadal timescales.
Representing moisture fluxes and phase changes in glacier debris cover using a single-reservoir approach
Authors: Collier E. , Nicholson L. I. , Brock B. W. , Maussion F. , Essery R. , Bush A. B. G.
Published: March 2014

Abstract. Due to the complexity of treating moisture in supraglacial debris, surface energy balance models to date have neglected moisture infiltration and phase changes in the debris layer. The latent heat flux (QL) is also often excluded due to the uncertainty in determining the surface vapour pressure. To quantify the importance of moisture on the surface energy and climatic mass balance (CMB) of debris-covered glaciers, we developed a simple, single-reservoir parameterization for the debris ice and water content, as well as an estimation of the latent heat flux. The parameterization was incorporated into a sophisticated CMB model adapted for debris-covered glaciers. We perform two point simulations using both our new "moist" and the conventional "dry" approaches, on the Miage Glacier, Italy, during summer 2008 and fall 2011. The former simulation coincides with available in situ glaciological and meteorological measurements, including the first eddy-covariance measurements of the turbulent fluxes over supraglacial debris, while the latter contains two refreeze events that permit evaluation of the influence of phase changes. The simulations demonstrate a clear influence of moisture on the glacier energy and mass dynamics. Heat transmission to the underlying ice is lower, as the effective thermal diffusivity of the debris is reduced by increases in the weighted density and specific heat capacity when water and ice are considered. In combination with surface heat extraction by QL, sub-debris ice melt is reduced by 2.3% in 2008 and by 2.8% in 2011 when moisture effects are included. However, mass loss due to surface vapour fluxes more than compensates for the reduction in ice melt, such that the total accumulated ablation increased by 5.3% in 2008 and by 2.8% in 2011. Although the parameterization is a simplified representation of the moist physics of glacier debris, it is a novel attempt at including moisture in a numerical model of debris-covered glaciers and opens up additional avenues of future research.
Takayasu arteritis in an HIV infected woman
Authors: Ojeda-Burgos Guillermo , Gómez-Rámirez Susana , Aguilar-Cuevas Rafael , Marquez-Solero Manuel
Published: March 2014

Takayasu arteritis (TA) is a rare chronic vasculitis with particular predilection for the aorta and its major branches. The precipitant factor of the pathological immune response is generally unknown and different factors have been implicated, including human immunodeficiency virus (HIV) infection. We report the case of a 46 year old woman who complained of a right hemicranial headache for a week and progressive loss of strength in the left side of the body. She was infected by HIV since 1996. After admission she progressed to hyporesponsive and hemiplegia. The absence of brachial pulse, a difference higher than 10 mmHg in the systolic blood pressure between both arms and radiological data were the criteria for the diagnosis of TA and secundary ischemic stroke
Some open problems and conjectures on submanifolds of finite type: recent development
Authors: Chen Bang-Yen
Published: March 2014

Submanifolds of finite type were introduced by the author during the late 1970s. The first results on this subject were collected in author's books [26,29]. In 1991, a list of twelve open problems and three conjectures on finite type submanifolds was published in [40]. A detailed survey of the results, up to 1996, on this subject was given by the author in [48]. Recently, the study of finite type submanifolds, in particular, of biharmonic submanifolds, have received a growing attention with many progresses since the beginning of this century. In this article, we provide a detailed account of recent development on the problems and conjectures listed in [40].
Is the Crime of Aggression Really Accountable? Reflections about Syria
Authors: Carvajal Ilich Felipe Corredor
Published: March 2014

Nobody can deny that Syria's situation is really serious, and requires an effective solution from the international community. However, that "intervention/solution" will have to respect the UN Charter and the Security Council's responsibilities like the non intervention principle and the new definition of the crime of aggression adopted in Kampala in 2010. This paper analyses the role of major powers (especially the USA and France) and the hypothetic application of the article 8 bis of the Rome Statute, if the Security Council is not able to find a consensus, and a "unilateral" solution was carried out by the aforementioned powerful States.
U.S. Territorial Exclusion in Federal Sentencing Research: Can it be Justified?
Authors: Iles Gale , Bumphus Vic , McGuffee Karen
Published: March 2014

There is a dearth of knowledge on sentencing process and outcomes in Guam, the Northern Mariana Islands, Puerto Rico and the United States Virgin Islands. It is not uncommon for researchers conducting national studies to intentionally exclude data from these American territories. Their actions have been justified on the grounds that territories have "distinctive" characteristics that warrant exclusion. Using federal sentencing data, this study explores whether the sentencing patterns observed in the territories are as "unique" as scholars assume and if so, in what ways and to what extent. Descriptive analysis reveals that attributes of offenders and case processing strategies are similar across the U.S. mainland and its territories. Although multivariate analysis revealed some notable differences (e.g., territories are more punitive than states) the larger finding is that there are more similarities than differences with regards to the processing of cases and outcomes. Implications of the study and directions for future research are discussed.
Group‐standing of whistler mode waves near the Moon
Authors: Tsugawa Y. , Katoh Y. , Terada N. , Ono T. , Tsunakawa H. , Takahashi F. , Shibuya H. , Shimizu H. , Matsushima M.
Published: March 2014

Narrowband whistler mode waves with frequencies near 1 Hz have been observed near the Moon. We reveal that the narrowband spectra, the frequency concentration near 1 Hz, and the relations between the wave vector, magnetic field vector, and sunward directions can be explained by a condition in which the group velocity vector is almost canceled by the solar wind velocity vector in the spacecraft frame. Hereafter, we refer to this condition as the group‐standing condition. The spectral density is modified and has a peak at the frequency satisfying the group‐standing condition because of the difference of the frequency width between the solar wind plasma frame and the spacecraft frame. In addition, if the waves were decelerated to be group‐standing, the conservation of the energy flux results in the intensification of the wave amplitude at that frequency. We also derive the analytical expression of the amount of the modifications, which depend on the group velocity. These effects can explain the narrowband spectra near 1 Hz and support the relations between the wave vector, magnetic field vector, and sunward directions. The estimated frequency which satisfies the group‐standing condition is in good agreement with the observed frequency within error bars of the estimation. Considering the group‐standing condition, we suggest that the narrowband waves observed in the spacecraft frame are originated from oblique whistler mode waves in the frequencies near the lower hybrid frequency, which are possibly generated by reflected ions from the lunar magnetic anomalies.
Quiet time short‐period and day‐to‐day variations in E × B drift studied using 150 km radar echoes from Gadanki
Authors: Pavan Chaitanya P. , Patra A. K. , Rao S. V. B.
Published: March 2014

In this paper we present short‐period and day‐to‐day variations in E × B drift during low solar and magnetically quiet conditions, based on radar observations of daytime 150 km echoes from Gadanki, India. Short‐period (<100 min) variations in E × B drift show amplitude as large as 7 m s−1 and display large day‐to‐day variation. Spectral analysis reveals that drift velocity fluctuations consist of several components of short periods in the range of 4–100 min. Among these periods, the most frequently occurring periods are 6–60 min. Observations also show that amplitudes of these periods increase with increasing period. Interestingly, signal‐to‐noise ratio (SNR) variations also show periods of 3–19 min, which have also been observed in velocity variations. In addition, amplitudes of the periodic variations in SNR tend to increase with increasing period, which is also similar to those observed in drift velocity fluctuations. No correlation between SNR and velocity variations, however, has been found. Noticeable day‐to‐day variations in drift velocity are found in all seasons, and the variation is as large as ±25 m s−1. Day‐to‐day variations also show wave‐like features with period of 2–4 days. Observed E × B drift variations of 7 m s−1 at short time scale and 25 m s−1 on a day‐to‐day basis indicate zonal electric field variations of 0.25 mV/m and 0.9 mV/m, respectively. We surmise that quiet time E × B drift variations with periods <100 min and 2–4 days are likely to be the manifestations of gravity wave and planetary wave wind‐induced electric fields, respectively, consistent with those reported earlier.
P‐V‐T equation of state of cubic CaSiO3 perovskite from first‐principles computation
Authors: Kawai Kenji , Tsuchiya Taku
Published: March 2014

Ca‐perovskite (Pv) is considered to be one of the most abundant minerals in the Earth's lower mantle (LM) with an ideal cubic structure at LM pressures and temperatures. In this study, a pressure‐volume‐temperature (P‐V‐T) equation of state model for Ca‐Pv is constructed using density functional first‐principles molecular dynamics simulations. The calculated P‐V‐T data yield  = 203.95 GPa,  = 46.17 Å3/formula unit, γ0 = 1.576, and q = 0.96 within the framework of the Mie–Grüneisen–Debye formulation. We compare the density and bulk sound velocity of Ca‐Pv with those of iron‐bearing Mg‐Pv and seismological values. Along an adiabatic temperature gradient, Ca‐Pv has ~2.5% higher density and ~0.7% faster bulk sound velocity than the preliminary reference Earth model, while it has ~3.8% higher density and ~2.7% slower bulk sound velocity than iron‐bearing Mg‐Pv. Our results indicate that a possible lateral variation in the Ca‐Pv fraction in the LM could produce an anticorrelation between VΦ and ρ.
Impact of large‐scale dynamics on the microphysical properties of midlatitude cirrus
Authors: Muhlbauer Andreas , Ackerman Thomas P. , Comstock Jennifer M. , Diskin Glenn S. , Evans Stuart M. , Lawson R. Paul , Marchand Roger T.
Published: March 2014

In situ microphysical observations of midlatitude cirrus collected during the Department of Energy Small Particles in Cirrus (SPARTICUS) field campaign are combined with an atmospheric state classification for the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site to understand statistical relationships between cirrus microphysics and the large‐scale meteorology. The atmospheric state classification is informed about the large‐scale meteorology and state of cloudiness at the ARM SGP site by combining ECMWF ERA‐Interim reanalysis data with 14 years of continuous observations from the millimeter‐wavelength cloud radar. Almost half of the cirrus cloud occurrences in the vicinity of the ARM SGP site during SPARTICUS can be explained by three distinct synoptic conditions, namely, upper level ridges, midlatitude cyclones with frontal systems, and subtropical flows. Probability density functions (PDFs) of cirrus microphysical properties such as particle size distributions (PSDs), ice number concentrations, and ice water content (IWC) are examined and exhibit striking differences among the different synoptic regimes. Generally, narrower PSDs with lower IWC but higher ice number concentrations are found in cirrus sampled in upper level ridges, whereas cirrus sampled in subtropical flows, fronts, and aged anvils show broader PSDs with considerably lower ice number concentrations but higher IWC. Despite striking contrasts in the cirrus microphysics for different large‐scale environments, the PDFs of vertical velocity are not different, suggesting that vertical velocity PDFs are a poor predictor for explaining the microphysical variability in cirrus. Instead, cirrus microphysical contrasts may be driven by differences in ice supersaturations or aerosols.
Ammonia emissions in the United States, European Union, and China derived by high‐resolution inversion of ammonium wet deposition data: Interpretation with a new agricultural emissions inventory (MASAGE_NH3)
Authors: Paulot F. , Jacob D. J. , Pinder R. W. , Bash J. O. , Travis K. , Henze D. K.
Published: March 2014

We use the adjoint of a global 3‐D chemical transport model (GEOS‐Chem) to optimize ammonia (NH3) emissions in the U.S., European Union, and China by inversion of 2005–2008 network data forwet deposition fluxes. Optimized emissions are derived on a 2° × 2.5° grid for individual months and years. Error characterization in the optimization includes model errors in precipitation. Annual optimized emissions are 2.8 Tg NH3−N a−1for the contiguous U.S., 3.1 Tg NH3−N a−1for the European Union, and 8.4 Tg NH3−N a−1for China. Comparisons to previous inventories for the U.S. and European Union show consistency (∼±15%) in annual totals but some large spatial and seasonal differences. We develop a new global bottom‐up inventory of NH3emissions (Magnitude And Seasonality of Agricultural Emissions model for NH3 (MASAGE_NH3)) to interpret the results of the adjoint optimization. MASAGE_NH3 provides information on the magnitude and seasonality of NH3emissions from individual crop and livestock sources on a 0.5° × 0.5° grid. We find that U.S. emissions peak in the spring in the Midwest due to corn fertilization and in the summer elsewhere due to manure. The seasonality of European emissions is more homogeneous with a well‐defined maximum in spring associated with manure and mineral fertilizer application. There is some evidence for the effect of European regulations of NH3emissions, notably a large fall decrease in northern Europe. Emissions in China peak in summer because of the summertime application of fertilizer for double cropping.
In situ Characterization of SiO2 Nanoparticle Biointeractions Using BrightSilica
Authors: Drescher Daniela , Zeise Ingrid , Traub Heike , Guttmann Peter , Seifert Stephan , Büchner Tina , Jakubowski Norbert , Schneider Gerd , Kneipp Janina
Published: March 2014

By adding a gold core to silica nanoparticles (BrightSilica), silica‐like nanoparticles are generated that, unlike unmodified silica nanoparticles, provide three types of complementary information to investigate the silica nano‐biointeraction inside eukaryotic cells in situ. Firstly, organic molecules in proximity of and penetrating into the silica shell in live cells are monitored by surface‐enhanced Raman scattering (SERS). The SERS data show interaction of the hybrid silica particles with tyrosine, cysteine and phenylalanine side chains of adsorbed proteins. Composition of the biomolecular corona of BrightSilica nanoparticles differs in fibroblast and macrophage cells. Secondly, quantification of the BrightSilica nanoparticles using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) micromapping indicates a different interaction of silica nanoparticles compared to gold nanoparticles under the same experimental conditions. Thirdly, the metal cores allow the investigation of particle distribution and interaction in the cellular ultrastructure by cryo nanoscale X‐ray tomography (cryo‐XT). In 3D reconstructions the assumption is confirmed that BrightSilica nanoparticles enter cells by an endocytotic mechanism. The high SERS intensities are explained by the beneficial plasmonic properties due to agglomeration of BrightSilica. The results have implications for the development of multi‐modal qualitative and quantitative characterization in comparative nanotoxicology and bionanotechnology.
Graphene Oxide Triggers Toll‐Like Receptors/Autophagy Responses In Vitro and Inhibits Tumor Growth In Vivo
Authors: Chen Guan‐Yu , Chen Chiu‐Ling , Tuan Hsing‐Yu , Yuan Pei‐Xiang , Li Kuei‐Chang , Yang Hong‐Jie , Hu Yu‐Chen
Published: March 2014

Graphene oxide (GO) is a nanomaterial with burgeoning bioapplications, while autophagy is implicated in cancer therapy. Although induction of autophagy by nanomaterials is reported, the underlying signaling mechanism in cancer cells and how this implicates the potential of GO in cancer therapy remain obscure. Here, it is shown that GO itself can induce the toll‐like receptors (TLRs) responses and autophagy in cancer cells and confer antitumor effects in mice. GO can be phagocytosed by CT26 colon cancer cells, simultaneously triggering autophagy as well as TLR‐4 and TLR‐9 signaling cascades. By dissecting the crosstalk between the TLRs and autophagy pathways, it is uncovered that the GO‐activated autophagy is regulated through the myeloid differentiation primary response gene 88 (MyD88)‐ and TNF receptor‐associated factor 6 (TRAF6)‐associated TLR‐4/9 signaling pathways. Injection of GO alone into immunocompetent mice bearing the CT26 colon tumors not only suppresses the tumor progression but also enhances cell death, autophagy, and immune responses within the tumor bed. These data altogether implicate the potential of GO as an effective nanomaterial for autophagy induction and cancer therapy.
Graphoepitaxial Directed Self‐Assembly of Polystyrene‐Block‐Polydimethylsiloxane Block Copolymer on Substrates Functionalized with Hexamethyldisilazane to Fabricate Nanoscale Silicon Patterns
Authors: Borah Dipu , Rasappa Sozaraj , Senthamaraikannan Ramsankar , Holmes Justin D. , Morris Michael A.
Published: March 2014

In block copolymer (BCP) nanolithography, microphase separated polystyrene‐block‐polydimethylsiloxane (PS‐b‐PDMS) thin films are particularly attractive as they can form small features and the two blocks can be readily differentiated during pattern transfer. However, PS‐b‐PDMS is challenging because the chemical differences in the blocks can result in poor surface‐wetting, poor pattern orientation control and structural instabilities. Usually the interfacial energies at substrate surface are engineered with the use of a hydroxyl‐terminated polydimethylsiloxane (PDMS‐OH) homopolymer brush. Herein, we report a facile, rapid and tuneable molecular functionalization approach using hexamethyldisilazane (HMDS). The work is applied to both planar and topographically patterned substrates and investigation of graphoepitaxial methods for directed self‐assembly and long‐range translational alignment of BCP domains is reported. The hexagonally arrangedin‐planeandout‐of‐planePDMS cylinders structures formed by microphase separation were successfully used as on‐chip etch masks for pattern transfer to the underlying silicon substrate. The molecular approach developed here affords significant advantages when compared to the more usual PDMS‐OH brushes used.
1D Co‐Pi Modified BiVO4/ZnO Junction Cascade for Efficient Photoelectrochemical Water Cleavage
Authors: Moniz Savio J. A. , Zhu Jun , Tang Junwang
Published: March 2014

The most important factors dominating solar hydrogen synthesis efficiency include light absorption, charge separation and transport, and surface chemical reactions (charge utilization). In order to tackle these factors, an ordered 1D junction cascade photoelectrode for water splitting, grown via a simple low‐cost solution‐based process and consisting of nanoparticulate BiVO4 on 1D ZnO rods with cobalt phosphate (Co‐Pi) on the surface is synthesized. Flat‐band measurements reveal the feasibility of charge transfer from BiVO4 to ZnO, supported by PL measurements and photocurrent observation in the presence of an efficient hole scavenger, which demonstrate that quenching of luminescence of BiVO4 and enhanced current are caused by electron transfer from BiVO4 to ZnO. A dramatic cathodic shift in onset potential under both visible and full arc irradiation, coupled with a 12‐fold increase in photocurrent (ca. 3 mA cm‐2) are observed compared to BiVO4, resulting in ≈47% IPCE at 410 nm (4% for BiVO4) with high solar energy conversion efficiency (0.88%). The reasons for these enhancements stem from enhanced light absorption and trapping, in situ rectifying electron transfer from BiVO4 to ZnO, hole transfer to Co‐Pi for water oxidation, and facilitating electron transport along 1D ZnO.
Photochemically Induced Reductive Elimination as a Route to a Zirconocene Complex with a Strongly Activated N2 Ligand
Authors: Margulieux Grant W. , Semproni Scott P. , Chirik Paul J.
Published: March 2014

The zirconocene dinitrogen complex [{(η5‐C5Me4H)2Zr}2(μ2,η2,η2‐N2)] was synthesized by photochemical reductive elimination from the corresponding zirconium bis(aryl) or aryl hydride complexes, providing a high‐yielding, alkali metal‐free route to strongly activated early‐metal N2 complexes. Mechanistic studies support the intermediacy of zirconocene arene complexes that in the absence of sufficient dinitrogen promote CH activation or undergo comproportion to formally ZrIII complexes. When N2 is in excess arene displacement gives rise to strong dinitrogen activation.
Solvent‐Assisted Linker Exchange: An Alternative to the De Novo Synthesis of Unattainable Metal–Organic Frameworks
Authors: Karagiaridi Olga , Bury Wojciech , Mondloch Joseph E. , Hupp Joseph T. , Farha Omar K.
Published: March 2014

Metal‐organic frameworks (MOFs) have gained considerable attention as hybrid materials—in part because of a multitude of potential useful applications, ranging from gas separation to catalysis and light harvesting. Unfortunately, de novo synthesis of MOFs with desirable function–property combinations is not always reliable and may suffer from vagaries such as formation of undesirable topologies, low solubility of precursors, and loss of functionality of the sensitive network components. The recently discovered synthetic approach coined solvent‐assisted linker exchange (SALE) constitutes a simple to implement strategy for circumventing these setbacks; its use has already led to the generation of a variety of MOF materials previously unobtainable by direct synthesis methods. This Review provides a perspective of the achievements in MOF research that have been made possible with SALE and examines the studies that have facilitated the understanding and broadened the scope of use of this invaluable synthetic tool.
A Highly Efficient and Broadly Applicable Cationic Gold Catalyst
Authors: Malhotra Deepika , Mashuta Mark S. , Hammond Gerald B. , Xu Bo
Published: March 2014

Gold catalysts capable of promoting reactions at low‐level loadings under mild conditions are the exception rather than the norm. We examined reactions where the regeneration of cationic gold catalyst (e.g., protodeauration) was the turnover limiting stage. By manipulating electron density on the substituents around phosphorus and introducing steric handles we designed a phosphine ligand that contains two electron‐rich ortho‐biphenyl groups and a cyclohexyl substituent. This ligand formed a gold complex that catalyzed common types of gold‐catalyzed reactions including intra‐ and intermolecular XH (X=C, N, O) additions to alkynes and cycloisomerizations, with high turnover numbers at room temperature or slightly elevated temperatures (≤50 °C). Our new ligand can be prepared in one step from commercially available starting materials.
Asymmetric Hydrogenation of α,β‐Unsaturated Nitriles with Base‐Activated Iridium N,P Ligand Complexes
Authors: Müller Marc‐André , Pfaltz Andreas
Published: March 2014

Although many chiral catalysts are known that allow highly enantioselective hydrogenation of a wide range of olefins, no suitable catalysts for the asymmetric hydrogenation of α,β‐unsaturated nitriles have been reported so far. We have found that Ir N,P ligand complexes, which under normal conditions do not show any reactivity towards α,β‐unsaturated nitriles, become highly active catalysts upon addition of N,N‐diisopropylethylamine. The base‐activated catalysts enable conjugate reduction of α,β‐unsaturated nitriles with H2 at low catalyst loadings, affording the corresponding saturated nitriles with high conversion and excellent enantioselectivity. In contrast, alkenes lacking a conjugated cyano group do not react under these conditions, making it possible to selectively reduce the conjugated CC bond of an α,β‐unsaturated nitrile, while leaving other types of CC bonds in the molecule intact.
New filtrate loss controller based on poly(methyl methacrylate‐co‐vinyl acetate)
Authors: Nunes Rita de Cassia P. , Pires Renata V. , Lucas Elizabete F. , Vianna Angelo , Lomba Rosana
Published: March 2014

The drilling of petroleum wells requires the use of suitable drilling fluids to ensure efficient operation without causing rock damage. Specific polymers have been used to control infiltration during drilling, to reduce operational problems. In this study, spherical microparticles of poly(methyl methacrylate‐co‐vinyl acetate) were synthesized (by suspension polymerization), characterized, and evaluated in terms of their performance in controlling filtrate loss of aqueous fluids. A filter press test with ceramic disk, simulating the rock, was used. The performance of the synthesized materials was compared with commercial polymers. It was observed that the performance of the material is directly associated with the relation between particle size and pore size of the rock specimen. Furthermore, for a suitable particle size, the rubbery characteristic of the material produces a more efficient filter cake, for filtrate control. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40646.
Active Cooperative Observation of A 3D Moving Target Using Two Dynamical Monocular Vision Sensors
Authors: Gu Feng , He Yuqing , Han Jianda
Published: March 2014

Vision‐based 3D moving target observation (3D‐VMTO) is a central problem in the field of mobile robotics. In this paper, a new 3D‐VMTO method called active cooperative observation is proposed through cooperation among two dynamical monocular vision sensors (MVSs). Under this method, an algorithm based on an extended set‐membership filter is designed to fuse observations from different MVSs. An optimal observation condition is then introduced as the constraint into the relative velocity coordinates based path planning scheme, so as to reduce the influence of relative positioning among MVSs and their target on cooperative observation results. Experiments on a multiple rotor‐flying‐robots testbed demonstrate the validity and feasibility of the proposed method.
Improved Stability Criteria for Linear Neutral Time‐Delay Systems
Authors: Xia Hongwei , Zhao Pingping , Li Li , Wang Yanmin , Wu Aiguo
Published: March 2014

This paper is concerned with the problem of stability analysis of linear neutral time delay systems. First, a new simple Lyapunov‐Krasovskii functional is constructed based on delay partitioning approach, then, a novel improved delay‐dependent stability criterion is established to guarantee the asymptotic stability of the neutral system. The obtained stability criterion is expressed in terms of linear matrix inequalities, which can be verified easily by means of standard software. Numerical examples are given to illustrate the effectiveness of the proposed method and the advantage over some existing results.
Optimal (r,N)‐policy for discrete‐time Geo ∕ G ∕ 1 queue with different input rate and setup time
Authors: Luo Chuanyi , Tang Yinghui , Yu Kaizhi , Ding Chuan
Published: March 2014

This paper presents a queue‐length analysis of Geo ∕ G ∕ 1 queue with (r,N)‐policy and different input rate. Using a different method, the recursive expressions of queue‐length distribution at different epochs are obtained. Furthermore, some performance measures are also investigated. Finally, the Tabu search algorithm is used to search the joint optimum value of (r,N), which minimizes the state‐dependent operating cost. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling and partial least squares approaches in OODA
Authors: Sánchez‐Rodríguez María Isabel , Caridad José M.
Published: March 2014

This is a discussion of the following paper: “Overview of object oriented data analysis” by J. Steve Marron and Andrés M. Alonso.
Redefining the surface anatomy of the saphenofemoral junction in vivo
Authors: Ali Mirjalili S. , Muirhead Jill C. , Stringer Mark D.
Published: March 2014

The surface anatomy of the saphenofemoral junction (SFJ) is especially relevant to surgeons. It is variably described in contemporary anatomy and clinical texts but is usually stated to lie 2.5–4 cm below and lateral to the pubic tubercle. The aim of this study was to map the SFJ accurately in healthy adults using ultrasound. One hundred healthy adults (mean age 27 years; 64 men) were scanned by an experienced sonographer using a 13–5 MHz linear probe. The center of the SFJ was recorded bilaterally in relation to the most superficial point of the pubic tubercle. The SFJ was readily identified in all participants. Its center was a mean of 2.4 ± 0.6 cm lateral (range 1–4.5 cm) and 1 ± 0.9 cm inferior to the pubic tubercle (range 2.5 above to 4 cm caudal to it). The junction was inferior to the pubic tubercle in 90% of lower limbs and at or above that level in 10%. In men, the SFJ was a mean of 2.6 cm lateral to the pubic tubercle and 1.2 cm inferior to it, compared with 2.2 and 0.6 cm, respectively, in women (P < 0.001). The SFJ was also slightly nearer the pubic tubercle in younger and thinner participants (P < 0.01). The center of the SFJ lies in a square extending 1–4 cm lateral and up to 3 cm below the pubic tubercle in >90% of adults. The junction is slightly closer to the pubic tubercle in women. These results provide a more robust guide to the surface anatomy of the normal SFJ. Clin. Anat. 27:915–919, 2014. © 2014 Wiley Periodicals, Inc.
Transition‐Metal‐Catalyzed Oxidation of Metallic Sn in NiO/SnO2 Nanocomposite
Authors: Hua Chunxiu , Fang Xiangpeng , Wang Zhaoxiang , Chen Liquan
Published: March 2014

It is well accepted that metallic tin as a discharge (reduction) product of SnOx cannot be electrochemically oxidized below 3.00 V versus Li+/Li0 due to the high stability of Li2O, though a similar oxidation can usually occur for a transition metal formed from the corresponding oxide. In this work, nanosized Ni2SnO4 and NiO/SnO2 nanocomposite were synthesized by coprecipitation reactions and subsequent heat treatment. Owing to the catalytic effect of nanosized metallic nickel, metallic tin can be electrochemically oxidized to SnO2 below 3.00 V. As a result, the reversible lithium‐storage capacities of the nanocomposite reach 970 mAh g−1 or above, much higher than the theoretical capacity (ca. 750 mAh g−1) of SnO2, NiO, or their composites. These findings extend the well‐known electrochemical conversion reaction to non‐transition‐metal compounds and may have important applications, for example, in constructing high‐capacity electrode materials and efficient catalysts.
Sarcoma classification: An update based on the 2013 World Health Organization Classification of Tumors of Soft Tissue and Bone
Authors: Doyle Leona A.
Published: March 2014

The 2013 World Health Organization Classification of Tumors of Soft Tissue and Bone incorporates changes in tumor classification, as well as new genetic insights into the pathogenesis of many different tumor types that have emerged over the 11 years since the publication of the prior volume. This article reviews changes in the classification of soft tissue and bone sarcomas as well as tumors of intermediate biologic potential in the 2013 World Health Organization volume, new molecular insights into these tumors, and associated surgical and clinical implications. Cancer 2014;120:1763–1774. © 2014 American Cancer Society.