bluuebunny/crossref_metadata_2025_split huggingface dataset:
Volume transport of the Antarctic Circumpolar Current: Production and validation of a 20 year long time series obtained from in situ and satellite observations
Authors: Koenig Zoé , Provost Christine , Ferrari Ramiro , Sennéchael Nathalie , Rio Marie‐Hélène 
Published: July 2014

AbstractA 20 year long volume transport time series of the Antarctic Circumpolar Current across the Drake Passage is estimated from the combination of information from in situ current meter data (2006–2009) and satellite altimetry data (1992–2012). A new method for transport estimates had to be designed. It accounts for the dependence of the vertical velocity structure on surface velocity and latitude. Yet unpublished velocity profile time series from Acoustic Doppler Current Profilers are used to provide accurate vertical structure estimates in the upper 350 m. The mean cross‐track surface geostrophic velocities are estimated using an iterative error/correction scheme to the mean velocities deduced from two recent mean dynamic topographies. The internal consistency and the robustness of the method are carefully assessed. Comparisons with independent data demonstrate the accuracy of the method. The full‐depth volume transport has a mean of 141 Sv (standard error of the mean 2.7 Sv), a standard deviation (std) of 13 Sv, and a range of 110 Sv. Yearly means vary from 133.6 Sv in 2011 to 150 Sv in 1993 and standard deviations from 8.8 Sv in 2009 to 17.9 Sv in 1995. The canonical ISOS values (mean 133.8 Sv, std 11.2 Sv) obtained from a year‐long record in 1979 are very similar to those found here for year 2011 (133.6 Sv and 12 Sv). Full‐depth transports and transports over 3000 m barely differ as in that particular region of Drake Passage the deep recirculations in two semiclosed basins have a close to zero net transport.
The surface mixed layer heat budget from mooring observations in the central Indian Ocean during Madden–Julian Oscillation events
Authors: Chi Nan‐Hsun , Lien Ren‐Chieh , D'Asaro Eric A. , Ma Barry B. 
Published: July 2014

AbstractThe oceanic surface mixed layer heat budget in the central equatorial Indian Ocean is calculated from observations at two mooring sites (0°S 79°E and 1.5°S 79°E) during three active and calm phases of Madden–Julian Oscillation (MJO) events between September 2011 and January 2012. At both mooring locations, the surface mixed layer is generally heated during MJO calm phases. During MJO active phases at both mooring locations, the surface mixed layer is always cooled by the net surface heat flux and also sometimes by the turbulent heat flux at the bottom of the surface mixed layer. The turbulent heat flux at the bottom of the surface mixed layer, however, varies greatly among different MJO active phases and between the two mooring locations. A barrier layer exerts control on the turbulent heat flux at the base of the surface mixed layer; we quantify this barrier layer strength by a “barrier layer potential energy,” which depends on the thickness of the barrier layer, the thickness of the surface mixed layer, and the density stratification across the isothermal layer. During one observed MJO active phase, a strong turbulent heat flux into the mixed layer was diagnosed, despite the presence of a 10−20 m thick barrier layer. This was due to the strong shear across the barrier layer driven by the westerly winds, which provided sufficient available kinetic energy to erode the barrier layer. To better simulate and predict net surface heat fluxes and the MJO, models must estimate the oceanic barrier layer potential energy, background shear, stratification, and surface forcing accurately.
Factors controlling the ice nucleating abilities of α‐pinene SOA particles
Authors: Ladino L. A. , Zhou S. , Yakobi‐Hancock J. D. , Aljawhary D. , Abbatt J. P. D. 
Published: July 2014

AbstractThe ice nucleation abilities of fresh, water‐soluble, internally mixed, and photochemically oxidized α‐pinene secondary organic aerosol (SOA) particles were investigated at cirrus cloud temperatures in a continuous flow diffusion chamber. SOA sampled from a flow tube (SOA‐fresh‐FT) mimicked freshly generated particles, while the water‐soluble organic compound fraction from a FT and smog chamber (SOA‐WSOC‐FT, SOA‐WSOC‐SC) mimicked cloud‐processed particles. SOA‐fresh‐FT, SOA‐WSOC‐FT, and SOA‐WSOC‐SC particles were not highly active at nucleating ice between 233 K and 213 K, with activation onsets (i.e.,  0.1% of particles forming ice) at or slightly above the theoretical homogeneous freezing line. A significant increase in the O/C of SOA‐WSOC‐SC via aqueous phase OH oxidation did not modify the ice nucleation abilities, indicating that the detailed composition of the particles is not of paramount importance to their ice nucleating abilities. Instead, precooling the SOA‐WSOC‐FT and SOA‐WSOC‐SC particles to 233 K dropped their ice nucleation onsets by up to 20% relative humidity with respect to ice, with lower temperatures likely driving the particles to be more viscous and solid‐like. However, it is possible that preactivation contributed to the reduction of the ice nucleation onsets. Particles composed of both SOA‐WSOC and ammonium sulfate (AS) were significantly less active in the deposition nucleation mode than pure, solid AS particles.
Mesospheric Inversion Layers at Chatanika, Alaska (65°N, 147°W): Rayleigh lidar observations and analysis
Authors: Irving Brita K. , Collins Richard L. , Lieberman Ruth S. , Thurairajah Brentha , Mizutani Kohei 
Published: July 2014

AbstractRayleigh lidar observations at Poker Flat Research Range, Chatanika, Alaska (65°N, 147°W), have yielded density and temperature measurements from 40 km to 80 km. These measurements have been made under clear skies at night between November 1997 and May 2009. We have identified and characterized 79 Mesospheric Inversion Layers (MILs) in the 40–70 km altitude region on 56 of 117 nights of observations between August and May. These 79 MILs have an average amplitude of 13 K, peak altitude of 61 km, topside lapse rate of 6 K/km, depth or thickness of 3 km, base altitude of 58 km, bottomside gradient of 5 K/km, and downward vertical velocity of 0.1 km/h based on the 2 h temperature profiles. MILs occur with a nightly occurrence rate of 48%, more frequently than previously reported at Arctic sites, but less frequently than at lower latitude sites. MILs are embedded in the larger planetary wave structure. MILs are found to occur most commonly in January as has been reported from lower latitude sites. We find that the planetary wave‐1 amplitudes are a factor 1.3 larger at an altitude of 5.0–6.5 scale heights (~32–39 km) on days when MILs are observed than when they are not observed. The planetary wave‐2 amplitudes are not significantly different when MILs are present and absent. We find that Eliassen‐Palm flux divergences at an altitude of 7–8 scale height (~45–52 km) are a factor 2.0 larger on nights when MILs are observed than when they are not observed. We also find that gravity wave potential energy densities are a factor 1.3 larger on nights when MILs are observed than on nights when they are not observed.
The effects of psammophilous plants on sand dune dynamics
Authors: Bel Golan , Ashkenazy Yosef 
Published: July 2014

AbstractMathematical models of sand dune dynamics have considered different types of sand dune cover. However, despite the important role of psammophilous plants (plants that flourish in moving‐sand environments) in dune dynamics, the incorporation of their effects into mathematical models of sand dunes remains a challenging task. Here we propose a nonlinear physical model for the role of psammophilous plants in the stabilization and destabilization of sand dunes. There are two main mechanisms by which the wind affects these plants: (i) sand drift results in the burial and exposure of plants, a process that is known to result in an enhanced growth rate, and (ii) strong winds remove shoots and rhizomes and seed them in nearby locations, enhancing their growth rate. Our model describes the temporal evolution of the fractions of surface cover of regular vegetation, biogenic soil crust, and psammophilous plants. The latter reach their optimal growth under either (i) specific sand drift or (ii) specific wind power. The model exhibits complex bifurcation diagrams and dynamics, which explain observed phenomena, and it predicts new dune stabilization scenarios. Depending on the climatological conditions, it is possible to obtain one, two, or, predicted here for the first time, three stable dune states. Our model shows that the development of the different cover types depends on the precipitation rate and the wind power and that the psammophilous plants are not always the first to grow and stabilize the dunes.
The heliospheric magnetic flux, solar wind proton flux, and cosmic ray intensity during the coming solar minimum
Authors: Smith Charles W. , McCracken K. G. , Schwadron Nathan A. , Goelzer Molly L. 
Published: July 2014

AbstractRecent papers have linked the heliospheric magnetic flux to the sunspot cycle with good correlation observed between prediction and observation. Other papers have shown a strong correlation between magnetic flux and solar wind proton flux from coronal holes. We combine these efforts with an expectation that the sunspot activity of the approaching solar minimum will resemble the Dalton or Gleissberg Minimum and predict that the magnetic flux and solar wind proton flux over the coming decade will be lower than at any time during the space age. Using these predictions and established theory, we also predict record high galactic cosmic ray intensities over the same years. The analysis shown here is a prediction of global space climate change within which space weather operates. It predicts a new parameter regime for the transient space weather behavior that can be expected during the coming decade.
Differential circadian catecholamine and cortisol responses between healthy women with and without a parental history of hypertension
Authors: James Gary D. , Alfarano Alexandria S. , van Berge‐Landry Helene M. 
Published: July 2014

ObjectivesPrevious studies suggest that otherwise healthy individuals who have a parental history of hypertension (PH+) have an accentuated reactive rise in catecholamines and cortisol to laboratory stressors as well as elevated plasma levels when compared with those with no parental history (PH−); however, few, if any, studies have evaluated whether parental history affects the responses of these hormones to changing environmental circumstances in everyday life. The purpose of this study was to compare urinary catecholamine (epinephrine and norepinephrine) and cortisol excretion and ambulatory blood pressures (BPs) across three daily microenvironments between women with and without a parental history of hypertension.MethodsThe women in the study (PH+, N = 62, age = 35.2 ± 9.1; PH−, N = 72, age = 33.8 ± 10.0) worked in clerical, technical, or professional positions at a major medical center in New York City. Urinary hormone excretion rates and ambulatory BP were measured across three daily microenvironments: work (11 am to 3 p.m.), home (approximately 6 p.m. to 10 p.m.), and during sleep (approximately 10 p.m. to 6 a.m.). History group comparisons by microenvironment were made using repeated‐measures ANCOVA and ANOVA analyses.ResultsThe results show that epinephrine excretion among PH+ women was 36% higher than PH− women (P < 0.008) over the entire day and that nocturnal cortisol excretion was also greater among PH+ women (P < 0.045). PH+ women also had statistically significantly higher systolic (4 mm Hg higher; P < 0.01) and diastolic (2 mm Hg higher, P < 0.03) BP when compared with PH− women across all daily microenvironments.ConclusionThese findings suggest that there may be genetically linked mechanisms which elevate tonic epinephrine levels and nocturnal cortisol levels that contribute to elevating circadian BP. Am. J. Hum. Biol. 26:753–759, 2014. © 2014 Wiley Periodicals, Inc.
Comparative effectiveness of medical and surgical therapy on olfaction in chronic rhinosinusitis: a prospective, multi‐institutional study
Authors: DeConde Adam S. , Mace Jess C. , Alt Jeremiah A. , Schlosser Rodney J. , Smith Timothy L. , Soler Zachary M. 
Published: July 2014

BackgroundEvidence comparing the impact of medical and surgical management of chronic rhinosinusitis on olfactory function is limited. This study evaluates olfactory outcomes in patients who failed initial medical management and elect either continued medical management or endoscopic sinus surgery (ESS) followed by medical management.MethodsAdult subjects were prospectively enrolled into a nonrandomized, multi‐institutional cohort. Baseline characteristics, quality‐of‐life and objective clinical findings were collected along with 2 quality‐of‐life disease‐specific measures, the Rhinosinusitis Disability Index (RSDI) and Sinonasal Outcome Test (SNOT‐22). The primary outcome measure was the posttreatment change (≥6 months) in the Brief Smell Identification Test (B‐SIT). Bivariate and multivariate analyses compared B‐SIT changes by treatment type while controlling for baseline cofactors.ResultsSubjects (n = 280) were enrolled between March 2011 and May 2013. Baseline B‐SIT scores (mean ± standard deviation) were comparable between medical and surgical treatment groups (8.8 ± 3.2 vs 9.0 ± 3.2; p = 0.703). Subjects with baseline impaired olfaction (n = 83; 29.6%) experienced B‐SIT improvement in both the medical (n = 17; 2.3 ± 2.8; p = 0.005) and surgical (n = 66; 2.1 ± 3.0; p < 0.001) cohort. A total of 38.6% of subjects with impaired olfaction return to normal olfaction at follow‐up with no difference identified between treatment modalities (p = 0.803). Multivariate analyses identified prior surgery as a predictor of less improvement regardless of treatment modality in patients with baseline impaired olfaction. Average changes in B‐SIT scores were comparable between treatment groups (p > 0.050).ConclusionSubjects electing ESS experienced gains in olfaction comparable to subjects electing continued medical management. Further study with larger sample size and more sensitive measures of olfaction are needed to determine differences between treatment groups.
Hemostasis with emergently modified application of intra‐aortic balloon occlusion in a patient with impending cardiac arrest following blunt proximal thigh amputation
Authors: Uchida Kotaro , Homma Hiroshi , Oda Jun , Yukioka Tetsuo , Nagai Noriko , Mishima Shiro , Ohta Shoichi 
Published: July 2014

CaseA 30‐year‐old woman had her left thigh run over by a train. We tried to compress the left femoral area to control the arterial bleeding, but bleeding continued from the stump and injured soft tissue. The application of a tourniquet bandage also failed because of the limited remaining thigh. She developed impending cardiac arrest. As the left femoral arterial pulsation was still palpable, we inserted an intra‐aortic balloon occlusion catheter percutaneously. The hemorrhage from the stump region decreased rapidly. She was transferred to an operating room to carry out surgical hemostasis, and it was confirmed with deflation of the balloon in the common iliac artery.OutcomeThere was no complication of the skin or soft tissue at the surgical site caused by impaired circulation, and her consciousness fully recovered.ConclusionWe report the successful control of bleeding by the emergently modified application of intra‐aortic balloon occlusion in the left common iliac artery.
Nachweis von Diwasserstoffbrücken in einem chiralen Amin‐Boran‐Komplex in Lösung mittels VCD‐Spektroskopie
Authors: Merten Christian , Berger Christopher J. , McDonald Robert , Xu Yunjie 
Published: July 2014

AbstractInfrarot‐ und Schwingungszirkulardichroismus‐Spektren (vibrational circular dichroism, VCD) eines chiralen Amin‐Borans in Lösung werden diskutiert. Durch Vergleich experimenteller und berechneter Spektren kann erstmals die Bildung von durch Diwasserstoffbrücken gebundenen Dimeren in Lösung nachgewiesen werden. Die VCD‐Banden der Dimere zeigen eine hohe Empfindlichkeit für die Bindungstopologie der Diwasserstoffbrücken, so dass detaillierte Strukturinformationen abgeleitet werden können. Weiterhin kann gezeigt werden, dass das Diwasserstoffbrückennetzwerk in Lösung und im kristallinen Zustand unterschiedlich ist.
Protein Interactions with Polymer Coatings and Biomaterials
Authors: Wei Qiang , Becherer Tobias , Angioletti‐Uberti Stefano , Dzubiella Joachim , Wischke Christian , Neffe Axel T. , Lendlein Andreas , Ballauff Matthias , Haag Rainer 
Published: July 2014

AbstractProtein adsorption is considered to be the most important factor of the interaction between polymeric biomaterials and body fluids or tissues. Water‐mediated hydrophobic and hydration forces as well as electrostatic interactions are believed to be the major factors of protein adsorption. A systematic analysis of various monolayer systems has resulted in general guidelines, the so‐called “Whitesides rules”. These concepts have been successfully applied for designing various protein‐resistant surfaces and are being studied to expand the understanding of protein–material interactions beyond existing limitations. Theories on the mechanisms of protein adsorption are constantly being improved due to the fast‐developing analytical technologies. This Review is aimed at improving these empirical guidelines with regard to present theoretical and analytical advances. Current analytical methods to test mechanistic hypotheses and theories of protein–surface interactions will be discussed. Special focus will be given to state‐of‐the‐art bioinert and biospecific coatings and their applications in biomedicine.
A Tailor‐Made Chimeric Thiamine Diphosphate Dependent Enzyme for the Direct Asymmetric Synthesis of (S)‐Benzoins
Authors: Westphal Robert , Vogel Constantin , Schmitz Carlo , Pleiss Jürgen , Müller Michael , Pohl Martina , Rother Dörte 
Published: July 2014

AbstractThiamine diphosphate dependent enzymes are well known for catalyzing the asymmetric synthesis of chiral α‐hydroxy ketones from simple prochiral substrates. The steric and chemical properties of the enzyme active site define the product spectrum. Enzymes catalyzing the carboligation of aromatic aldehydes to (S)‐benzoins have not so far been identified. We were able to close this gap by constructing a chimeric enzyme, which catalyzes the synthesis of various (S)‐benzoins with excellent enantiomeric excess (>99 %) and very good conversion.
Computational fluid dynamics analysis to effects of geometrical design and physical property on complete suspension of floating solids in stirred tanks
Authors: Qiao Shengchao , Wang Rijie , Yan Yuefei , Yang Xiaoxia 
Published: July 2014

ABSTRACTThe computational fluid dynamics methodology was developed to qualitatively study effects of geometrical design and physical property on the mixing quality of floating solids in stirred tanks with an up‐pumping pitched blade turbine. The multiple reference frame approach was used to model the relative motion between rotating impeller and stationary baffles. Two important mixing parameters, power number (Np) and standard deviation (σ), were used to predict critical impeller speed (NCS) for complete suspension of floating solids and compare the mixing efficiency. Predicted results were compared with the experiment results in the open literature and were explained with published mechanisms or theories concerning solid suspension. Reasonable agreements were achieved. Copyright © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Enhancement in pyroelectric properties of PZT‐PVA polymer nanocomposites with addition of PAA
Authors: Uma Sreekumar , Philip Jacob 
Published: July 2014

ABSTRACTComposites comprising of pyroelectric ceramics and electro‐active polymers have gained importance currently as materials for thermal sensing applications, as their unique features and relevant properties can be tailored easily. In this work nanoparticles of PZT have been embedded into PVA/PAA copolymer matrix to form 0 to 3 nanocomposites. Films of the composites are prepared following solvent cast method after dispersing ceramic nanopowder homogeneously in the copolymer matrix with different wt % of the PZT powder. Relevant properties such as dielectric constant and loss factor, pyroelectric coefficients, thermal conductivity, and specific heat capacity as well as Shore hardness have been measured. The material figures of merit for pyroelectric detection have also been determined and reported. It is found that pyroelectric sensing properties of a film of the composite with 20 wt % PZT are comparable to those of commercially used β‐PVDF film for the same application, but with a lower figure of merit. However, it provides greater mouldability and simpler processibility for the fabrication of bulk sensors and actuators. So this composite can be considered as a potential material for the design and fabrication of mouldable pyroelectric detectors and actuators. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41142.
Organic solvent nanofiltration with a Poly(dimethylsiloxane) membrane: Parameters affecting its sieving properties
Authors: Leitner Loïc , Harscoat‐Schiavo Christelle , Kapel Romain , Vallieres Cécile 
Published: July 2014

ABSTRACTIn this study, retention experiments were performed to characterize the variable sieving properties of a poly(dimethylsiloxane) (PDMS) membrane in relation with operating parameters. The swelling, transmembrane pressure, and temperature are all known to impact the physicochemical properties and morphology of PDMS polymer and were therefore varied for the purposes of our retention experiments which assessed them with the homologous series of polyethylene glycols (PEGs; 200–1500 g mol−1). The objectives were twofold—first, to evaluate the capacity to induce a targeted molecular weight cutoff (MWCO) by selecting appropriate filtration conditions and second to better understand the mechanisms involved during solvent‐resistant nanofiltration with PDMS. The selected solvents or solvent/solvent mixtures used throughout this study were found to induce swelling ratios of 1.16 (ethanol/ethyl acetate: 25/75), 1.26 (ethyl acetate), 1.33 (ethyl acetate/toluene: 50/50), and 1.41 (toluene), respectively. Linear correlations were obtained between the MWCO and the swelling ratio induced by each solvent and between the MWCO and the transmembrane pressure. Pore size calculations using solvent flux and retention data confirmed the variable sieving properties of the PDMS membrane in relation to the solvent‐induced swelling and applied transmembrane pressure. In addition, the study of the solute‐transfer rate through several operating conditions showed that both diffusive and convective transports occurred for the PEG solutes and that their respective contributions appeared dependent on the variable pore size of the PDMS membrane. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41171.