Many Particle Hardy-Inequalities

In this paper we prove three differenttypes of the so-called many-particle Hardy inequalities. One of them is a "classical type" which is valid in any dimesnion $d\neq 2$. The second type deals with two-dimensional magnetic Dirichlet forms where every particle is supplied with a soplenoid. Finally we show that Hardy inequalities for Fermions hold true in all dimensions.Comment: 20 page

Numerical Models for the Diffuse Ionized Gas in Galaxies. II. Three-dimensional radiative transfer in inhomogeneous interstellar structures as a tool for analyzing the diffuse ionized gas

Aims: We systematically explore a plausible subset of the parameter space involving effective temperatures and metallicities of the ionizing stellar sources, the effects of the hardening of their radiation by surrounding leaky HII regions with different escape fractions, as well as different scenarios for the clumpiness of the DIG, and compute the resulting line strength ratios for a number of diagnostic optical emission lines. Methods: For the ionizing fluxes we compute a grid of stellar spectral energy distributions (SEDs) from detailed, fully non-LTE model atmospheres that include the effects of stellar winds and line blocking and blanketing. To calculate the ionization and temperature structure in the HII regions and the diffuse ionized gas we use spherically symmetric photoionization models as well as state-of-the-art three-dimensional (3D) non-LTE radiative transfer simulations, considering hydrogen, helium, and the most abundant metals. Results: We provide quantitative predictions of how the line ratios from HII regions and the DIG vary as a function of metallicity, stellar effective temperature, and escape fraction from the HII region. The range of predicted line ratios reinforces the hypothesis that the DIG is ionized by (filtered) radiation from hot stars; however, comparison of observed and predicted line ratios indicates that the DIG is typically ionized with a softer SED than predicted by the chosen stellar population synthesis model. Even small changes in simulation parameters like the clumping factor can lead to considerable variation in the ionized volume. Both for a more homogeneous gas and a very inhomogeneous gas containing both dense clumps and channels with low gas density, the ionized region in the dilute gas above the galactic plane can cease to be radiation-bounded, allowing the ionizing radiation to leak into the intergalactic medium.Comment: 21 pages, 9 figures, accepted by A&

Stochastic analysis of ocean wave states with and without rogue waves

This work presents an analysis of ocean wave data including rogue waves. A stochastic approach based on the theory of Markov processes is applied. With this analysis we achieve a characterization of the scale dependent complexity of ocean waves by means of a Fokker-Planck equation, providing stochastic information of multi-scale processes. In particular we show evidence of Markov properties for increment processes, which means that a three point closure for the complexity of the wave structures seems to be valid. Furthermore we estimate the parameters of the Fokker-Planck equation by parameter-free data analysis. The resulting Fokker-Planck equations are verified by numerical reconstruction. This work presents a new approach where the coherent structure of rogue waves seems to be integrated into the fundamental statistics of complex wave states.Comment: 18 pages, 13 figure

How Phenol and α-Tocopherol React with Ambient Ozone at Gas/Liquid Interfaces

The exceptional ability of α-tocopherol (α-TOH) for scavenging free radicals is believed to also underlie its protective functions in respiratory epithelia. Phenols, however, can scavenge other reactive species. Herein, we report that α-TOH/α-TO^− reacts with closed-shell O_3(g) on the surface of inert solvent microdroplets in <1 ms to produce persistent α-TO−O_n^−(n = 1−4) adducts detectable by online thermospray ionization mass spectrometry. The prototype phenolate PhO^−, in contrast, undergoes electron transfer under identical conditions. These reactions are deemed to occur at the gas/liquid interface because their rates: (1) depend on pH, (2) are several orders of magnitude faster than within microdroplets saturated with O_3(g). They also fail to incorporate solvent into the products: the same α-TO−On^− species are formed on acetonitrile or nucleophilic methanol microdroplets. α-TO−O_n(=1−3)^− signals initially evolve with [O_3(g)] as expected from first-generation species, but α-TO−O^− reacts further with O_3(g) and undergoes collisionally induced dissociation into a C_(19)H_(40) fragment (vs C_(19)H_(38) from α-TO^−) carrying the phytyl side chain, whereas the higher α-TO−O_(n≥2)^− homologues are unreactive toward O_3(g) and split CO_2 instead. On this basis, α-TO−O^− is assigned to a chroman-6-ol (4a, 8a)-ene oxide, α-TO−O2^− to an endoperoxide, and α-TO−O3^− to a secondary ozonide. The atmospheric degradation of the substituted phenols detected in combustion emissions is therefore expected to produce related oxidants on the aerosol particles present in the air we breathe

Absorption of Inhaled NO_2

Nitrogen dioxide (NO_2), a sparingly water-soluble π-radical gas, is a criteria air pollutant that induces adverse health effects. How is inhaled NO_2(g) incorporated into the fluid microfilms lining respiratory airways remains an open issue because its exceedingly small uptake coefficient (γ 10^(−7)−10^(−8)) limits physical dissolution on neat water. Here, we investigate whether the biological antioxidants present in these fluids enhance NO_2(g) dissolution by monitoring the surface of aqueous ascorbate, urate, and glutathione microdroplets exposed to NO_2(g) for 1 ms via online thermospray ionization mass spectrometry. We found that antioxidants catalyze the hydrolytic disproportionation of NO_2(g), 2NO_2(g) + H_2O(l) = NO_3^−(aq) + H^+(aq) + HONO, but are not consumed in the process. Because this function will be largely performed by chloride, the major anion in airway lining fluids, we infer that inhaled NO_2(g) delivers H^+, HONO, and NO_3^− as primary transducers of toxic action without antioxidant participation

Proton Availability at the Air/Water Interface

The acidity of the water surface sensed by a colliding gas is determined in experiments in which the protonation of gaseous trimethylamine (TMA) on aqueous microjets is monitored by online electrospray mass spectrometry as a function of the pH of the bulk liquid (pH_(BLK)). TMAH^+ signal intensities describe a titration curve whose equivalence point at pH_(BLK) 3.8 is dramatically smaller than the acidity constant of trimethylammonium in bulk solution, pK_A(TMAH^+) = 9.8. Notably, the degree of TMA protonation above pH_(BLK) 4 is enhanced hundred-fold by submillimolar LiCl or NaCl and weakly inhibited at larger concentrations. Protonation enhancements are associated with the onset of significant direct kinetic solvent hydrogen isotope effects. Since TMA(g) can be protonated by H_2O itself only upon extensive solvent participation, we infer that H3O^+ emerges at the surface of neat water below pH_(BLK) 4

Prompt Formation of Organic Acids in Pulse Ozonation of Terpenes on Aqueous Surfaces

A major atmospheric process, the gas-phase ozonation of terpenes yields suites of products via a cascade of chemically activated intermediates that ranges from primary ozonides to dioxiranes. If a similar mechanism operated in water, as it is generally assumed, such intermediates would be deactivated within picoseconds and, henceforth, be unable to produce carboxylic acids in microseconds. Herein, we report the online electrospray mass spectrometric detection of (M + 2O – H^+) and (M + 3O – H^+) carboxylates on the surface of aqueous β-caryophyllene (C_(15)H_(24), M = 204 Da) microjets exposed to a few ppmv of O_3(g) for < 10 μs. Since neither species is formed on dry solvent microjets and both incorporate deuterium from D_2O, we infer that carboxylates ensue from the interaction of nascent intermediates with interfacial water via heretofore unreported processes. These interfacial events proceed much faster than those in bulk liquids saturated with ozone

Ozone Oxidizes Glutathione to a Sulfonic Acid

Biosurfaces are universally covered with fluid microfilms containing reduced glutathione (GSH) and other antioxidants whose putative roles include the detoxification of ambient ozone (O_3). It is generally believed that O_3 accepts an electron from the thiolate GS^(2-) function [pK_a(GS^-) = 8.8] of GSH to produce thiyl GS^(•-) radicals en route to the disulfide GSSG. Here, we report novel electrospray mass spectrometry experiments showing that sulfonates (GSO_3^-/GSO_3^(2-)), not GSSG, are the exclusive final products on the surface of aqueous GSH microdroplets exposed to dilute O_3(g) for ~1 ms. The higher reactivity of the thiolate GS^(2-) toward O_3(g) over the thiol GS^- is kinetically resolved in this time frame due to slow GS^- acid dissociation. However, our experiments also show that O_3 will be largely scavenged by the more reactive ascorbate coantioxidant in typical interfacial biofilms. The presence of GSSG and the absence of GSO_3^-/GSO_3^(2-) in extracellular lining fluids are therefore evidence of GSH oxidation by species other than O_3

Time to guide: evidence for delayed attentional guidance in contextual cueing

Contextual cueing experiments show that, when displays are repeated, reaction times (RTs) to find a target decrease over time even when the observers are not aware of the repetition. Recent evidence suggests that this benefit in standard contextual cueing tasks is not likely to be due to an improvement in attentional guidance (Kunar, Flusberg, Horowitz, & Wolfe, 2007). Nevertheless, we ask whether guidance can help participants find the target in a repeated display, if they are given sufficient time to encode the display. In Experiment 1 we increased the display complexity so that it took participants longer to find the target. Here we found a larger effect of guidance than in a condition with shorter RTs. Experiment 2 gave participants prior exposure to the display context. The data again showed that with more time participants could implement guidance to help find the target, provided that there was something in the search stimuli locations to guide attention to. The data suggest that, although the benefit in a standard contextual cueing task is unlikely to be a result of guidance, guidance can play a role if it is given time to develop