Brown carbon aerosol in the North American continental troposphere: sources, abundance, and radiative forcing

Chemical components of organic aerosol (OA) selectively absorb light at short wavelengths. In this study, the prevalence, sources, and optical importance of this so called brown carbon (BrC) aerosol component are investigated throughout the North American continental tropospheric column during a summer of extensive biomass burning. Spectrophotometric absorption measurements on extracts of bulk aerosol samples collected from an aircraft over the central USA were analyzed to directly quantify BrC abundance. BrC was found to be prevalent throughout the 1 to 12 km altitude measurement range, with dramatic enhancements in biomass-burning plumes. BrC to black carbon (BC) ratios, under background tropospheric conditions, increased with altitude, consistent with a corresponding increase in the absorption Ångström exponent (AAE) determined from a three-wavelength particle soot absorption photometer (PSAP). The sum of inferred BC absorption and measured BrC absorption at 365 nm was within 3 % of the measured PSAP absorption for background conditions and 22 % for biomass burning. A radiative transfer model showed that BrC absorption reduced top-of atmosphere (TOA) aerosol forcing by ∼ 20 % in the background troposphere. Extensive radiative model simulations applying this study background tropospheric conditions provided a look-up chart for determining radiative forcing efficiencies of BrC as a function of a surface-measured BrC : BC ratio and single scattering albedo (SSA). The chart is a first attempt to provide a tool for better assessment of brown carbon’s forcing effect when one is limited to only surface data. These results indicate that BrC is an important contributor to direct aerosol radiative forcing

Quantum Dissension: Generalizing Quantum Discord for Three-Qubit States

We introduce the notion of quantum dissension for a three-qubit system as a measure of quantum correlations. We use three equivalent expressions of three-variable mutual information. Their differences can be zero classically but not so in quantum domain. It generalizes the notion of quantum discord to a multipartite system. There can be multiple definitions of the dissension depending on the nature of projective measurements done on the subsystems. As an illustration, we explore the consequences of these multiple definitions and compare them for three-qubit pure and mixed GHZ and W states. We find that unlike discord, dissension can be negative. This is because measurement on a subsystem may enhance the correlations in the rest of the system. This approach can pave a way to generalize the notion of quantum correlations in the multiparticle setting.Comment: 9 pages 6 figures typo fixed and some arguments adde

Many-body perturbation calculation of spherical nuclei with a separable monopole interaction: I. Finite nuclei

We present calculations of ground state properties of spherical, doubly closed-shell nuclei from $^{16}$O to $^{208}$Pb employing the techniques of many-body perturbation theory using a separable density dependent monopole interaction. The model gives results in Hartree-Fock order which are of similar quality to other effective density-dependent interactions. In addition, second and third order perturbation corrections to the binding energy are calculated and are found to contribute small, but non-negligible corrections beyond the mean-field result. The perturbation series converges quickly, suggesting that this method may be used to calculate fully correlated wavefunctions with only second or third order perturbation theory. We discuss the quality of the results and suggest possible methods of improvement.Comment: 20 Pages, 11 figure

Primary thermometry in the intermediate Coulomb blockade regime

We investigate Coulomb blockade thermometers (CBT) in an intermediate temperature regime, where measurements with enhanced accuracy are possible due to the increased magnitude of the differential conductance dip. Previous theoretical results show that corrections to the half width and to the depth of the measured conductance dip of a sensor are needed, when leaving the regime of weak Coulomb blockade towards lower temperatures. In the present work, we demonstrate experimentally that the temperature range of a CBT sensor can be extended by employing these corrections without compromising the primary nature or the accuracy of the thermometer.Comment: 8 pages, 4 figure

HOMFLY and superpolynomials for figure eight knot in all symmetric and antisymmetric representations

Explicit answer is given for the HOMFLY polynomial of the figure eight knot $4_1$ in arbitrary symmetric representation R=[p]. It generalizes the old answers for p=1 and 2 and the recently derived results for p=3,4, which are fully consistent with the Ooguri-Vafa conjecture. The answer can be considered as a quantization of the \sigma_R = \sigma_{[1]}^{|R|} identity for the "special" polynomials (they define the leading asymptotics of HOMFLY at q=1), and arises in a form, convenient for comparison with the representation of the Jones polynomials as sums of dilogarithm ratios. In particular, we construct a difference equation ("non-commutative A-polynomial") in the representation variable p. Simple symmetry transformation provides also a formula for arbitrary antisymmetric (fundamental) representation R=[1^p], which also passes some obvious checks. Also straightforward is a deformation from HOMFLY to superpolynomials. Further generalizations seem possible to arbitrary Young diagrams R, but these expressions are harder to test because of the lack of alternative results, even partial.Comment: 14 page

Quantum discord evolution of three-qubit states under noisy channels

We investigated the dissipative dynamics of quantum discord for correlated qubits under Markovian environments. The basic idea in the present scheme is that quantum discord is more general, and possibly more robust and fundamental, than entanglement. We provide three initially correlated qubits in pure Greenberger-Horne-Zeilinger (GHZ) or W state and analyse the time evolution of the quantum discord under various dissipative channels such as: Pauli channels $\sigma_{x}$, $\sigma_{y}$, and $\sigma_{z}$, as well as depolarising channels. Surprisingly, we find that under the action of Pauli channel $\sigma_{x}$, the quantum discord of GHZ state is not affected by decoherence. For the remaining dissipative channels, the W state is more robust than the GHZ state against decoherence. Moreover, we compare the dynamics of entanglement with that of the quantum discord under the conditions in which disentanglement occurs and show that quantum discord is more robust than entanglement except for phase flip coupling of the three qubits system to the environment.Comment: 17 pages, 4 figures, accepted for publication in EPJ

Spherically symmetric dissipative anisotropic fluids: A general study

The full set of equations governing the evolution of self--gravitating spherically symmetric dissipative fluids with anisotropic stresses is deployed and used to carry out a general study on the behaviour of such systems, in the context of general relativity. Emphasis is given to the link between the Weyl tensor, the shear tensor, the anisotropy of the pressure and the density inhomogeneity. In particular we provide the general, necessary and sufficient, condition for the vanishing of the spatial gradients of energy density, which in turn suggests a possible definition of a gravitational arrow of time. Some solutions are also exhibited to illustrate the discussion.Comment: 28 pages Latex. To appear in Phys.Rev.

TOM40 Mediates Mitochondrial Dysfunction Induced by α-Synuclein Accumulation in Parkinson's Disease.

Alpha-synuclein (α-Syn) accumulation/aggregation and mitochondrial dysfunction play prominent roles in the pathology of Parkinson's disease. We have previously shown that postmortem human dopaminergic neurons from PD brains accumulate high levels of mitochondrial DNA (mtDNA) deletions. We now addressed the question, whether alterations in a component of the mitochondrial import machinery -TOM40- might contribute to the mitochondrial dysfunction and damage in PD. For this purpose, we studied levels of TOM40, mtDNA deletions, oxidative damage, energy production, and complexes of the respiratory chain in brain homogenates as well as in single neurons, using laser-capture-microdissection in transgenic mice overexpressing human wildtype α-Syn. Additionally, we used lentivirus-mediated stereotactic delivery of a component of this import machinery into mouse brain as a novel therapeutic strategy. We report here that TOM40 is significantly reduced in the brain of PD patients and in α-Syn transgenic mice. TOM40 deficits were associated with increased mtDNA deletions and oxidative DNA damage, and with decreased energy production and altered levels of complex I proteins in α-Syn transgenic mice. Lentiviral-mediated overexpression of Tom40 in α-Syn-transgenic mice brains ameliorated energy deficits as well as oxidative burden. Our results suggest that alterations in the mitochondrial protein transport machinery might contribute to mitochondrial impairment in α-Synucleinopathies

When global norms meet local politics : localising transparency in extractive industries governance

Processes of norm localisation play a crucial role in shaping the extent to which global governance norms are institutionalised at national and sub‐national levels. This article explores the politics of norm localisation through an empirical investigation of how global norms of “transparency” were localised in sub‐national processes of extractive industry governance in Bojonegoro, Indonesia. Previous theories of localisation have emphasised “constructivist” dynamics through which patterns of norm localisation are shaped decisively by efforts to build normative or cognitive congruence with local ideas and identities. In contrast, the mix of a newly democratised environment, the persistent power of corporatist elite networks and a populist style of local politics prevailing in Bojonegoro have diminished the significance of such constructivist dynamics as a basis for explaining varied patterns of norm localisation. Instead, patterns of norm localisation have depended crucially on the capacity of local political leaders to harness global governance norms instrumentally as a basis for consolidating and strengthening their own local power base. These findings have important implications for both theoretical and practical understandings of how global norm localisation processes vary in response to the contrasting political contexts in which global governance norms targeting the extractive sector are implemented