bluuebunny/crossref_metadata_2025 huggingface dataset:
Symmetry of minimizers with a level surface parallel to the boundary
Authors: Ciraolo Giulio , Magnanini Rolando , Sakaguchi Shigeru
Published: October 2015

We consider the functional

\mathcal I_{\Omega} (v) = \int_{\Omega} [f(|Dv|) - v] dx,

where

\Omega

is a bounded domain and

f

is a convex function. Under general assumptions on

f

, Crasta [Cr1] has shown that if

\mathcal I_{\Omega}

admits a minimizer in

W_0^{1,1}(\Omega)

depending only on the distance from the boundary of

\Omega

, then

\Omega

must be a ball. With some restrictions on

f

, we prove that spherical symmetry can be obtained only by assuming that the minimizer has
one
level surface parallel to the boundary (i.e. it has only a level surface in common with the distance).

We then discuss how these results extend to more general settings, in particular to functionals that are not differentiable and to solutions of fully nonlinear elliptic and parabolic equations.
Anti-self-dual orbifolds with cyclic quotient singularities
Authors: Lock Michael T. , Viaclovsky Jeff A.
Published: October 2015

An index theorem for the anti-self-dual deformation complex on anti-self-dual orbifolds with cyclic quotient singularities is proved. We present two applications of this theorem. The first is to compute the dimension of the deformation space of the Calderbank–Singer scalar-flat Kähler toric ALE spaces. A corollary of this is that, except for the Eguchi–Hanson metric, all of these spaces admit non-toric anti-self-dual deformations, thus yielding many new examples of anti-self-dual ALE spaces. For our second application, we compute the dimension of the deformation space of the canonical Bochner-Kähler metric on any weighted projective space

\mathbb {CP}^2_{(r,q,p)}

for relatively prime integers

1 < r < q < p

. A corollary of this is that, while these metrics are rigid as Bochner–Kähler metrics, infinitely many of these admit non-trivial self-dual deformations, yielding a large class of new examples of self-dual orbifold metrics on certain weighted projective spaces.
Amenable hyperbolic groups
Authors: Caprace Pierre-Emmanuel , de Cornulier Yves , Monod Nicolas , Tessera Romain
Published: October 2015

We give a complete characterization of the locally compact groups that are non elementary Gromov-hyperbolic and amenable. They coincide with the class of mapping tori of discrete or continuous one-parameter groups of compacting automorphisms. We moreover give a description of all Gromov-hyperbolic locally compact groups with a cocompact amenable subgroup: modulo a compact normal subgroup, these turn out to be either rank one simple Lie groups, or automorphism groups of semiregular trees acting doubly transitively on the set of ends. As an application, we show that the class of hyperbolic locally compact groups with a cusp-uniform nonuniform lattice is very restricted.
Finite part of operator K-theory for groups with rapid decay
Authors: Gong Sherry
Published: October 2015

In this paper we study the part of the

K

-theory of the reduced

C^*

-algebra arising from torsion elements of the group, and in particular we study the pairing of

K

-theory with traces and when traces can detect certain

K

-theory elements. In the case of groups with Property RD, we give a condition on the growth of conjugacy classes that determines whether they can be detected. Moreover, in the case that they can be detected, we show that nonzero elements in the part of the

K

-theory generated by torsion elements are not in the image of the assembly map

K^G_0(EG) \to K_0(C^*G)

. One application of this result is a lower bound for the structure groups of certain manifolds.
On Frobenius and separable algebra extensions in monoidal categories: applications to wreaths
Authors: Bulacu Daniel , Torrecillas Blas
Published: October 2015

We characterize Frobenius and separable monoidal algebra extensions

i: R \to S

in terms given by

R

and

S

. For instance, under some conditions, we show that the extension is Frobenius, respectively separable, if and only if

S

is a Frobenius, respectively separable, algebra in the category of bimodules over

R

. In the case when

R

is separable we show that the extension is separable if and only if

S

is a separable algebra. Similarly, in the case when

R

is Frobenius and separable in a sovereign monoidal category we show that the extension is Frobenius if and only if

S

is a Frobenius algebra and the restriction at

R

of its Nakayama automorphism is equal to the Nakayama automorphism of

R

. As applications, we obtain several characterizations for an algebra extension associated to a wreath to be Frobenius, respectively separable.
Families of hyperfinite subfactors with the same standard invariant and prescribed fundamental group
Authors: Brothier Arnaud , Vaes Stefaan
Published: October 2015

We construct irreducible hyperfinite subfactors of index 6 with a prescribed fundamental group from a large family containing all countable and many uncountable subgroups of

\mathbb R_+

. We also prove that there are unclassifiably many irreducible hyperfinite group-type subfactors of index 6 that all have the same standard invariant. More precisely, we associate such a subfactor to every ergodic measure preserving automorphism of the interval [0; 1] and prove that the resulting subfactors are isomorphic if and only if the automorphisms are conjugate.
Property A and uniform embedding for locally compact groups
Authors: Deprez Steven , Li Kang
Published: October 2015

For locally compact groups, we define an analogue to Yu’s property A that he defined for discrete metric spaces.We show that our property A for locally compact groups agrees with Roe’s notion of property A for proper metric spaces, defined in [11]. We prove that many of the results that are known to hold in the discrete setting, hold also in the locally compact setting. In particular, we show that property A is equivalent to amenability at infinity (see [9] for the discrete case), and that a locally compact group with property A embeds uniformly into a Hilbert space (see [17] for the discrete case). We also prove that the Baum–Connes assembly map with coeffcients is split-injective, for every locally compact group that embeds uniformly into a Hilbert space. This extends results by Skandalis, Tu and Yu [13], and by Chabert, Echterhoff and Oyono-Oyono [4].
Spectral sections, twisted rho invariants and positive scalar curvature
Authors: Benameur Moulay-Tahar , Mathai Varghese
Published: October 2015

We had previously defined in [10], the rho invariant

\rho_{spin}(Y,\Epsilon,H, g)

for the twisted Dirac operator

\def\partialslash{\mathrlap{/}{\partial}}
\partialslash^{\mathcal E}_H

on a closed odd dimensional Riemannian spin manifold

(Y, g)

, acting on sections of a flat hermitian vector bundle

\Epsilon

over

Y

, where

H = \sum i^{j+1} H_{2j+1}

is an odd-degree differential form on

Y

and

H_{2j+1}

is a real-valued differential form of degree

{2j+1}

. Here we show that it is a conformal invariant of the pair

(H, g)

. In this paper we express the defect integer

\rho_{spin}(Y,\Epsilon,H, g) - \rho_{spin}(Y,\Epsilon, g)

in terms of spectral flows and prove that

\rho_{spin}(Y,\Epsilon,H, g) \in \mathbb Q

, whenever

g

is a Riemannian metric of positive scalar curvature. In addition, if the maximal Baum–Connes conjecture holds for

\pi_1(Y)

(which is assumed to be torsion-free), then we show that

\rho_{spin}(Y,\Epsilon,H, rg) =0

for all

r \gg 0

, significantly generalizing results in [10]. These results are proved using the Bismut–Weitzenböck formula, a scaling trick, the technique of noncommutative spectral sections, and the Higson–Roe approach [22].
Mathematical Logic: Proof Theory, Constructive Mathematics
Authors: Buss Samuel R. , Kohlenbach Ulrich , Rathjen Michael
Published: October 2015

The workshop “Mathematical Logic: Proof Theory, Constructive Mathematics” was centered around proof-theoretic aspects of current mathematics, constructive mathematics and logical aspects of computational complexity
Mini-Workshop: Eigenvalue Problems in Surface Superconductivity
Authors: Bonnaillie-Noël Virginie , Kovařík Hynek , Pankrashkin Konstantin
Published: October 2015

The aim of the meeting is to discuss several classes of Schrödinger equations appearing within the Ginzburg-Landau theory of superconductivity. The related problems are discussed from several perspectives including semiclassical analysis, PDE in non-smooth domains, geometric spectral theory and operator theory, which should provide a new insight into various phenomena appearing in superconducting systems.
Henstock multivalued integrability in Banach lattices with respect to pointwise non atomic measures
Authors: Boccuto Antonio , Candeloro Domenico , Sambucini Anna Rita
Published: October 2015

Henstock-type integrals are considered, for multifunctions taking values in the family of weakly compact and convex subsets of a Banach lattice

X

. The main tool to handle the multivalued case is a Rådström-type embedding theorem established by C. C. A. Labuschagne, A. L. Pinchuck, C. J. van Alten in 2007. In this way the norm and order integrals reduce to that of a single-valued function taking values in an

M

-space, and new proofs are deduced for some decomposition results recently stated in two recent papers by Di Piazza and Musiał based on the existence of integrable selections.
Quasi-filling fractal layers
Authors: Capitanelli Raffaela , Vivaldi Maria Agostina
Published: October 2015

We consider second order transmission problems across Koch-type curves formulated as boundary value problems for elliptic operators in a quasi-filling geometry for the fibers. We use a variational approach and the M-convergence methods. We prove that the solution of the transmission problem across a Koch-type curve is the limit of the solutions of suitable second order transmission problems across polygonal curves.
A group-theoretic viewpoint on Erdős–Falconer problems and the Mattila integral
Authors: Greenleaf Allan , Iosevich Alex , Liu Bochen , Palsson Eyvindur
Published: October 2015

We obtain nontrivial exponents for Erdős–Falconer type point configuration problems. Let

T_k(E)

denote the set of distinct congruent

k

-dimensional simplices determined by

(k+1)

-tuples of points from

E

. For

1 \le k \le d

, we prove that there exists a

t_{k,d} < d

such that, if

E \subset {\mathbb R}^d

,

d \ge 2

, with

\mathrm {dim}_{{\mathcal H}}(E)>t_{k,d}

, then the

{k+1 \choose 2}

-imensional Lebesgue measure of

T_k(E)

is positive. Results of this type were previously obtained for triangles in the plane

(k=d=2)

in [8] and for higher

k

and

d

in [7]. We improve upon those exponents, using a group action perspective, which also sheds light on the classical approach to the Falconer distance problem.
Calderón reproducing formulas and applications to Hardy spaces
Authors: Auscher Pascal , McIntosh Alan G.R. , Morris Andrew J.
Published: October 2015

We establish new Calderón holomorphic functional calculus whilst the synthesising function interacts with

D

through functional calculus based on the Fourier transform. We apply these to prove the embedding

H^p_D(\wedge T^*M) \subseteq L^p(\wedge T^*M)

,

1 \leq p \leq 2

, for the Hardy spaces of differential forms introduced by Auscher, McIntosh and Russ, where

D=d+d^*

is the Hodge–Dirac operator on a complete Riemannian manifold

M

that has doubling volume growth. This fills a gap in that work. The new reproducing formulas also allow us to obtain an atomic characterisation of

H^1_D(\wedge T^*M)

. The embedding

H^p_L \subseteq L^p

,

1 \leq p \leq 2

, where

L

is either a divergence form elliptic operator on

\mathbb R^n

, or a nonnegative self-adjoint operator that satisfies Davies–Gaffney estimates on a doubling metric measure space, is also established in the case when the semigroup generated by the adjoint

-L^*

is ultracontractive.
Dynamical dessins are dense
Authors: Bishop Christopher J. , Pilgrim Kevin M.
Published: October 2015

We apply a recent result of the first author to prove the following result: any continuum in the plane can be approximated arbitrarily closely in the Hausdorff topology by the Julia set of a post critically finite polynomial with two finite postcritical points.
Intrinsic ultracontractivity via capacitary width
Authors: Aikawa Hiroaki
Published: October 2015

The semigroup associated with the Dirichlet heat kernel is said to be intrinsic ultracontractive if

(i) the Dirichlet realization of the associated self adjoint operator has the first positive eigenvalue with positive L2 eigenfunction;

(ii) the heat kernel is bounded above and below by the product of the eigenfunctions with positive multiplicative constants depending on time.

We give an upper and lower estimate of the first eigenvalue in terms of capacitary width, which yields a sharp sufficient condition for (i). Our parabolic argument also yields an exponential decay property of a certain caloric measure. Then, the caloric measure is controlled by the elliptic Green function with the aid of a parabolic box argument. This is a crucial step for (ii). We give a sharp sufficient integral condition for intrinsic ultracontractivity in terms of capacitary width. A similar integral condition for the boundary Harnack principle is also obtained. Under geometric specifications, these integral conditions generalize known results and give more precise conditions. Sharpness is examined by an infinite funnel, for which we obtain a complete characterization of intrinsic ultracontractivity. Our method is purely analytic and elementary; it enables us to dispense with logarithmic Sobolev inequalities.
Nonsolvability of the asymptotic Dirichlet problem for some quasilinear elliptic PDEs on Hadamard manifolds
Authors: Holopainen Ilkka , Ripoll Jaime B.
Published: October 2015

We show, by modifying Borbély’s example, that there are 3-dimensional Cartan–Hadamard manifolds

M

, with sectional curvatures

≤ −1

, such that the asymptotic Dirichlet problem for a class of quasilinear elliptic PDEs, including the minimal graph equation, is not solvable.
Existence of a Positive Solution to Kirchhoff Problems Involving the Fractional Laplacian
Authors: Ge Bin , Zhang Chao
Published: October 2015

The goal of this paper is to establish the existence of a positive solution to the following fractional Kirchhoff-type problem

\left(1+\lambda\int_{\mathbb{R}^N} \left( \big|(-\Delta)^{\frac{\alpha}{2}}u(x) \big|^{2}+V(x)u^2 \right)dx \right)\big[(-\Delta)^\alpha u+V(x)u\big]=f(u) \quad {\rm in} \ \mathbb{R}^N,

where

N\geq 2

,

\lambda\geq 0

is a parameter,

\alpha\in(0,1)

,

(-\Delta)^\alpha

stands for the fractional Laplacian,

f\in C(\mathbb{R}_+,\mathbb{R}_+)

. Using a variational method combined with suitable truncation techniques, we obtain the existence of at least one positive solution without compactness conditions.
Resolving ice cloud optical thickness biases between CALIOP and MODIS using infrared retrievals
Authors: Holz R. E. , Platnick S. , Meyer K. , Vaughan M. , Heidinger A. , Yang P. , Wind G. , Dutcher S. , Ackerman S. , Amarasinghe N. , Nagle F. , Wang C.
Published: October 2015

Abstract. Despite its importance as one of the key radiative properties that determines the impact of upper tropospheric clouds on the radiation balance, ice cloud optical thickness (IOT) has proven to be one of the more challenging properties to retrieve from space-based remote sensing measurements. In particular, optically thin upper tropospheric ice clouds (cirrus) have been especially challenging due to their tenuous nature, extensive spatial scales, and complex particle shapes and light scattering characteristics. The lack of independent validation motivates the investigation presented in this paper, wherein systematic biases between MODIS Collection 5 (C5) and CALIOP Version 3 (V3) unconstrained retrievals of tenuous IOT (< 3) are examined using a month of collocated A-Train observations. An initial comparison revealed a factor of two bias between the MODIS and CALIOP IOT retrievals. This bias is investigated using an infrared (IR) radiative closure approach that compares both products with MODIS IR cirrus retrievals developed for this assessment. The analysis finds that both the MODIS C5 and the unconstrained CALIOP V3 retrievals are biased (high and low, respectively) relative to the IR IOT retrievals. Based on this finding, the MODIS and CALIOP algorithms are investigated with the goal of explaining and minimizing the biases relative to the IR. For MODIS we find that the assumed ice single scattering properties used for the C5 retrievals are not consistent with the mean IR COT distribution. The C5 ice scattering database results in the asymmetry parameter (g) varying as a function of effective radius with mean values that are too large. The MODIS retrievals have been brought into agreement with the IR by adopting a new ice scattering model for Collection 6 (C6) consisting of a modified gamma distribution comprised of a single habit (severely roughened aggregated columns); the C6 ice cloud optical property models have a constant g ~ 0.75 in the mid-visible spectrum, 5–15 % smaller than C5. For CALIOP, the assumed lidar ratio for unconstrained retrievals is fixed at 25 sr for the V3 data products. This value is found to be inconsistent with the constrained (predominantly nighttime) CALIOP retrievals. An experimental data set was produced using a modified lidar ratio of 32 sr for the unconstrained retrievals (an increase of 28 %), selected to provide consistency with the constrained V3 results. These modifications greatly improve the agreement with the IR and provide consistency between the MODIS and CALIOP products. Based on these results the recently released MODIS C6 optical products use the single habit distribution given above, while the upcoming CALIOP V4 unconstrained algorithm will use higher lidar ratios for unconstrained retrievals.
Upper-tropospheric humidity changes under constant relative humidity
Authors: Gierens K. , Eleftheratos K.
Published: October 2015

Abstract. Theoretical derivations are given on the change of upper-tropospheric humidity (UTH) in a warming climate. Considered view is that the atmosphere, getting moister with increasing temperatures, will retain a constant relative humidity. In the present study we show that the upper-tropospheric humidity, a weighted mean over a relative humidity profile, will change in spite of constant relative humidity. The simple reason for this is that the weighting function, that defines UTH, changes in a moister atmosphere. Through analytical calculations using observations and through radiative transfer calculations we demonstrate that two quantities that define the weighting function of UTH can change: the water vapour scale height and the peak emission altitude. Applying these changes to real profiles of relative humidity shows that absolute UTH changes typically do not exceed 1 %. If larger changes would be observed they would be an indication of climatological changes of relative humidity. As such, an increase in UTH between 1980 and 2009 in the northern midlatitudes as shown by earlier studies using HIRS data, may be an indication of an increase in relative humidity as well.
Toward consistency between bottom-up CO2 emissions trends and top-down atmospheric measurements in the Los Angeles megacity
Authors: Newman S. , Xu X. , Gurney K. R. , Hsu Y.-K. , Li K.-F. , Jiang X. , Keeling R. , Feng S. , O'Keefe D. , Patarasuk R. , Wong K. W. , Rao P. , Fischer M. L. , Yung Y. L.
Published: October 2015

Abstract. Large urban emissions of greenhouse gases result in large atmospheric enhancements relative to background that are easily measured. Using CO2 mole fractions and Δ14C and δ13C values of CO2 in the Los Angeles megacity observed in inland Pasadena (2006–2013) and coastal Palos Verdes peninsula (autumn 2009–2013), we have determined time series for CO2 contributions from fossil fuel combustion for both sites and broken those down into contributions from petroleum/gasoline and natural gas burning for Pasadena. We find a 10 % reduction in Pasadena CO2 emissions from fossil fuel combustion during the Great Recession of 2008–2010, which is consistent with the bottom-up inventory determined by the California Air Resources Board. The isotopic variations and total atmospheric CO2 from our observations are used to infer seasonality of natural gas and petroleum combustion. For natural gas, inferred emissions are out of phase with the seasonal cycle of total natural gas combustion seasonal patterns in bottom-up inventories but are consistent with the seasonality of natural gas usage by the area's electricity generating power plants. For petroleum, the inferred seasonality of CO2 emissions from burning petroleum is delayed by several months relative to usage indicated by statewide gasoline taxes. Using the high-resolution Hestia-LA data product to compare emissions from parts of the basin sampled by winds at different times of year, we find that variations in observed fossil fuel CO2 reflect seasonal variations in wind direction. The seasonality of the local CO2 excess from fossil fuel combustion along the coast, on Palos Verdes peninsula, is higher in fall and winter than spring and summer, almost completely out of phase with that from Pasadena, also because of the annual variations of winds in the region. Variations in fossil fuel CO2 signals are consistent with sampling the bottom-up Hestia-LA fossil CO2 emissions product for sub-city source regions in the LA megacity domain when wind directions are considered.
Two-dimensional distribution of living benthic foraminifera in anoxic sediment layers of an estuarine mudflat (Loire estuary, France)
Authors: Thibault de Chanvalon A. , Metzger E. , Mouret A. , Cesbron F. , Knoery J. , Rozuel E. , Launeau P. , Nardelli M. P. , Jorissen F. J. , Geslin E.
Published: October 2015

Abstract. We present a new rapid and accurate protocol to simultaneously sample benthic living foraminifera in two dimensions in a centimetre-scale vertical grid and dissolved iron and phosphorus in two dimensions at high resolution (200 μm). Such an approach appears crucial for the study of foraminiferal ecology in highly dynamic and heterogeneous sedimentary systems, where dissolved iron shows a strong variability at the centimetre scale. On the studied intertidal mudflat of the Loire estuary, foraminiferal faunas are dominated by Ammonia tepida, which accounts for 92 % of the living (CellTracker Green(CTG)-labelled) assemblage. The vertical distribution shows a maximum density in the oxygenated 0–0.4 cm surface layer. A sharp decrease is observed in the next 2 cm, followed by a second, well-defined maximum in the suboxic sediment layer (3–8 cm depth). The presented method yields new information concerning the 2-D distribution of living A. tepida in suboxic layers. First, the identification of recent burrows by visual observation of the sediment cross section and the burrowing activity as deduced from the dissolved iron spatial distribution show no direct relation to the distribution of A. tepida at the centimetre scale. This lack of relation appears contradictory to previous studies (Aller and Aller, 1986; Berkeley et al., 2007). Next, the heterogeneity of A. tepida in the 3–8 cm depth layer was quantified by means of Moran's index to identify the scale of parameters controlling the A. tepida distribution. The results reveal horizontal patches with a characteristic length of 1–2 cm. These patches correspond to areas enriched in dissolved iron likely generated by anaerobic degradation of labile organic matter. These results suggest that the routine application of our new sampling strategy could yield important new insights about foraminiferal life strategies, improving our understanding of the role of these organisms in coastal marine ecosystems.
Temperature-mediated changes in microbial carbon use efficiency and 13C discrimination
Authors: Lehmeier C. A. , Ballantyne IV F. , Min K. , Billings S. A.
Published: October 2015

Abstract. Understanding how carbon dioxide (CO2) flux from soils feeds back to climate warming depends in part on our ability to quantify the efficiency with which microorganisms convert soil organic carbon (C) into either biomass or CO2. Quantifying ecosystem-level respiratory CO2 losses often also requires assumptions about stable C isotope fractionations associated with the microbial transformation of soil organic substrates. However, the diversity of organic substrates' δ13C and the challenges of measuring microbial C use efficiency (CUE) in soils fundamentally limit our ability to project soil, and thus ecosystem, C budgets in a warming climate. Here, we quantify the effect of temperature on C fluxes during metabolic transformations of cellobiose, a common microbial substrate, by a cosmopolitan soil microorganism growing at a constant rate. Specific respiration rate increased by 250 % between 13 and 26.5 °C, decreasing CUE from 77 to 56 %. Specific respiration rate was positively correlated with an increase in respiratory 13C discrimination from 4.4 to 6.7 ‰ across the same temperature range. This first demonstration of a direct link between temperature, microbial CUE and associated isotope fluxes provides a critical step towards understanding δ13C of respired CO2 at multiple scales, and towards a framework for predicting future soil C fluxes.
Evolution of dissolved and particulate chromophoric materials during the VAHINE mesocosm experiment in the New Caledonian coral lagoon (South West Pacific)
Authors: Tedetti M. , Marie L. , Röttgers R. , Rodier M. , Van Wambeke F. , Helias S. , Caffin M. , Cornet-Barthaux V. , Dupouy C.
Published: October 2015

Abstract. In the framework of the VAHINE project, we investigated the spectral characteristics and the variability of dissolved and particulate chromophoric materials throughout a 23 day mesocosm experiment conducted in the South West Pacific at the exit of the New Caledonian coral lagoon (22°29.073 S–166°26.905 E) from 13 January to 4 February 2013. Samples were collected in a mesocosm fertilized with phosphorus at 1, 6 and 12 m depth and in the surrounding waters. Light absorption coefficients of chromophoric dissolved organic matter (CDOM) (ag(λ)), particulate matter (ap(λ)) and CDOM + particulate matter (ag+p(λ)) were measured using a point-source integrating-cavity absorption meter (PSICAM), while fluorescent DOM (FDOM) components were determined from excitation-emission matrices (EEMs) combined with parallel factor analysis (PARAFAC). The evolutions of ag(λ), ap(λ) and ag+p(λ) in the mesocosm were similar to those of total chlorophyll a concentration, Synechococcus spp. and picoeukaryote abundances, bacterial production, particulate organic nitrogen and total organic carbon concentrations, with roughly a decrease from the beginning of the experiment to days 9–10, and an increase from days 9–10 to the end of the experiment. In the surrounding waters, the same trend was observed but the increase was much less pronounced, emphasizing the effect of the phosphorus fertilization on the mesocosm's plankton community. Correlations suggested that both Synechococcus cyanobacteria and heterotrophic bacteria were strongly involved in the production of CDOM and absorption of particulate matter. The increase in phytoplankton activities during the second part of the experiment led to a higher contribution of particulate material in the absorption budget at 442 nm. The three FDOM components identified (tryptophan-, tyrosine- and UVC humic-like fluorophores) did not follow the evolution of CDOM and particulate matter, proving that these were driven by different production/degradation processes. Finally, this works indicates a coupling between the dynamics of the N2 fixation and that of chromophoric material in the South West Pacific through Synechococcus bloom.
Early westward flow across the Tasman Gateway
Authors: Sijp W. P. , von der Heydt A. S. , Bijl P. K.
Published: October 2015

Abstract. The timing and role in ocean circulation and climate of the opening of Southern Ocean gateways is as yet elusive. Recent micropaleontological studies suggest the onset of throughflow of surface waters from the SW Pacific into the Australo-Antarctic Gulf through a southern shallow opening of the Tasman Gateway from 49–50 Ma onwards. Here, we present the first model results specific to the early-to-middle Eocene where, in agreement with the field evidence, southerly shallow opening of the Tasman Gateway indeed causes a westward flow across the Tasman Gateway. As a result, modelled estimates of dinoflagellate biogeography are in agreement with the recent findings. Crucially, in this situation where Australia is still situated far south and almost attached to Antarctica, the Drake Passage must be sufficiently restricted to allow the prevailing easterly wind pattern to set up this southerly restricted westward flow. In contrast, an open Drake Passage, to 517 m depth, leads to an eastward flow, even when the Tasman Gateway and the Australo-Antarctic gulf are entirely contained within the latitudes of easterly wind.
On the use of Schwarz–Christoffel conformal mappings to the grid generation for global ocean models
Authors: Xu S. , Wang B. , Liu J.
Published: October 2015

Abstract. In this article we propose two grid generation methods for global ocean general circulation models. Contrary to conventional dipolar or tripolar grids, the proposed methods are based on Schwarz–Christoffel conformal mappings that map areas with user-prescribed, irregular boundaries to those with regular boundaries (i.e., disks, slits, etc.). The first method aims at improving existing dipolar grids. Compared with existing grids, the sample grid achieves a better trade-off between the enlargement of the latitudinal–longitudinal portion and the overall smooth grid cell size transition. The second method addresses more modern and advanced grid design requirements arising from high-resolution and multi-scale ocean modeling. The generated grids could potentially achieve the alignment of grid lines to the large-scale coastlines, enhanced spatial resolution in coastal regions, and easier computational load balance. Since the grids are orthogonal curvilinear, they can be easily utilized by the majority of ocean general circulation models that are based on finite difference and require grid orthogonality. The proposed grid generation algorithms can also be applied to the grid generation for regional ocean modeling where complex land–sea distribution is present.
Air Quality Modeling with WRF-Chem v3.5 in East and South Asia: sensitivity to emissions and evaluation of simulated air quality
Authors: Zhong M. , Saikawa E. , Liu Y. , Naik V. , Horowitz L. W. , Takigawa M. , Zhao Y. , Lin N.-H. , Stone E. A.
Published: October 2015

Abstract. We conducted simulations using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) version 3.5 to study air quality in East and South Asia at a spatial resolution of 20 km × 20 km. We find large discrepancies between two existing emissions inventories: the Regional Emission Inventory in Asia version 2 (REAS) and the Emissions Database for Global Atmospheric Research version 4.2 (EDGAR) at the provincial level in China, with maximum differences up to 500 % for CO emissions, 190 % for NO, and 160 % for primary PM10. Such differences in the magnitude and the spatial distribution of emissions for various species lead to 40–70 % difference in surface PM10 concentrations, 16–20 % in surface O3 mixing ratios, and over 100 % in SO2 and NO2 mixing ratios in the polluted areas of China. Our sensitivity run shows WRF-Chem is sensitive to emissions, with the REAS-based simulation reproducing observed concentrations and mixing ratios better than the EDGAR-based simulation for July 2007. We conduct further model simulations using REAS emissions for January, April, July, and October in 2007 and evaluate simulations with available ground-level observations. The model results show clear regional variations in the seasonal cycle of surface PM10 and O3 over East and South Asia. The model meets the air quality model performance criteria for both PM10 (mean fractional bias, MFB ≤ ± 60 %) and O3 (MFB ≤ ± 15 %) in most of the observation sites, although the model underestimates PM10 over Northeast China in January. The model predicts the observed SO2 well at sites in Japan, while it tends to overestimate SO2 in China in July and October. The model underestimates most observed NO2 in all four months. These findings suggest that future model development and evaluation of emission inventories and models are needed for particulate matter and gaseous pollutants in East and South Asia.
Characterization of stony soils' hydraulic conductivity using laboratory and numerical experiments
Authors: Pichault M. , Beckers E. , Degré A. , Garré S.
Published: October 2015

Abstract. Determining soil hydraulic properties is of major concern in various fields of study. Though stony soils are widespread across the globe, most studies deal with gravel-free soils so that the literature describing the impact of stones on soil's hydraulic conductivity is still rather scarce. Most frequently, models characterizing the saturated hydraulic conductivity of stony soils assume that the only effect of rock fragments is to reduce the volume available for water flow and therefore they predict a decrease in hydraulic conductivity with an increasing stoniness. The objective of this study is to assess the effect of rock fragments on the saturated and unsaturated hydraulic conductivity. This was done by means of laboratory and numerical experiments involving different amounts and types of coarse fragments. We compared our results with values predicted by the aforementioned models. Our study suggests that considering that stones only reduce the volume available for water flow might be ill-founded. We pointed out several drivers of the saturated hydraulic conductivity of stony soils, not considered by these models. On the one hand, the shape and the size of inclusions may substantially affect the hydraulic conductivity. On the other hand, the presence of rock fragments can counteract and even overcome the effect of a reduced volume in some cases. We attribute this to the creation of voids at the fine earth-stone interface. Nevertheless, these differences are mainly important near to saturation. However, we come up with a more nuanced view regarding the validity of the models under unsaturated conditions. Indeed, under unsaturated conditions, the models seem to represent the hydraulic behaviour of stones reasonably well.
Simulating the climatic mass balance of Svalbard glaciers from 2003 to 2013 with a high-resolution coupled atmosphere-glacier model
Authors: Aas K. S. , Dunse T. , Collier E. , Schuler T. V. , Berntsen T. K. , Kohler J. , Luks B.
Published: October 2015

Abstract. In this study we simulate the climatic mass balance of Svalbard glaciers with a coupled atmosphere-glacier model with 3 km grid spacing, from September 2003 to September 2013. We find a mean specific net mass balance of −167 mm w.e. yr−1, corresponding to a mean annual mass loss of about 5.7 Gt, with large interannual variability. Our results are compared with a comprehensive set of mass balance, meteorological and satellite measurements. Model temperature biases of 0.17 and −1.9 °C are found at two glacier automatic weather station sites. Simulated climatic mass balance is mostly within about 0.1 m w.e. yr−1 of stake measurements, and simulated winter accumulation at the Austfonna ice cap shows mean absolute errors of 0.05 and 0.06 m w.e. yr−1 when compared to radar-derived values for the selected years 2004 and 2006. Comparison of surface height changes from 2003 to 2008 from model, and satellite altimetry reveals good agreement in both mean values and regional differences. The largest deviations from observations are found for winter accumulation at Hansbreen (up to around 1 m w.e. yr−1), a site where sub-grid topography and wind redistribution of snow are important factors. Comparison with simulations using a 9 km grid spacing reveal considerable differences on regional and local scales. In addition, the 3 km grid spacing allows for a much more detailed comparison with observations than what is possible with a 9 km grid spacing. Further decreasing the grid spacing to 1 km appears to be less significant, although in general precipitation amounts increase with resolution. Altogether, the model compares well with observations and offers possibilities for studying glacier climatic mass balance on Svalbard both historically as well as based on climate projections.
Small-scale disturbances in the stratigraphy of the NEEM ice core: observations and numerical model simulations
Authors: Jansen D. , Llorens M.-G. , Westhoff J. , Steinbach F. , Kipfstuhl S. , Bons P. D. , Griera A. , Weikusat I.
Published: October 2015

Abstract. Disturbances on the centimetre scale in the stratigraphy of the NEEM ice core (North Greenland) can be mapped by an optical line scanner as long as the ice does have a visual layering, such as, for example, cloudy bands. Different focal depths allow, to a certain extent, a three dimensional view of the structures. In this study we present a detailed analysis of the visible folds, discuss their characteristics and frequency and present examples of typical fold structures. We also analyse the structures with regard to the deformation boundary conditions under which they formed. The structures evolve from gentle waves at about 1500 m to overturned z-folds with increasing depth. Occasionally, the folding causes significant thickening of layers. Their similar-fold shape indicates that they are passive features and are probably not initiated by rheology differences between alternating layers. Layering is heavily disturbed and tracing of single layers is no longer possible below a depth of 2160 m. c-axes orientation distributions for the corresponding core sections were analysed where available in addition to visual stratigraphy. The data show axial-plane parallel strings of grains with c-axis orientations that deviate from that of the matrix, which shows a single-maximum fabric at the depth where the folding occurs. Numerical modelling of crystal viscoplasticity deformation and dynamic recrystallisation was used to improve the understanding of the formation of the observed structures during deformation. The modelling reproduces the development of bands of grains with a tilted orientation relative to the single maximum fabric of the matrix, and also the associated local deformation. We conclude from these results that the observed folding is a consequence of localized deformation at the boundaries of kink bands.
Analysis of the mass balance time series of glaciers in the Italian Alps
Authors: Carturan L. , Baroni C. , Brunetti M. , Carton A. , Dalla Fontana G. , Salvatore M. C. , Zanoner T. , Zuecco G.
Published: October 2015

Abstract. This work presents an analysis of the mass balance series of nine Italian glaciers, which were selected based on the length, continuity and reliability of observations. All glaciers experienced mass loss in the observation period, which is variable for the different glaciers and ranges between 10 and 47 years. The longest series display increasing mass loss rates, that were mainly due to increased ablation during longer and warmer ablation seasons. The mean annual mass balance (Ba) in the decade from 2004 to 2013 ranged from −1788 mm to −763 mm w.e. yr−1. Low-altitude glaciers with low elevation ranges are more out of balance than the higher, larger and steeper glaciers, which maintain residual accumulation areas in their upper reaches. The response of glaciers is mainly controlled by the combination of October–May precipitation and June–September temperature, but rapid geometric adjustments and atmospheric changes lead to modifications in their response to climatic variations. In particular, a decreasing correlation of Ba with the June–September temperature and an increasing correlation with October–May precipitation are observed for some glaciers. In addition, the October–May temperature tends to become significantly correlated with Ba, possibly indicating a decrease in the fraction of solid precipitation, and/or increased ablation, during the accumulation season. Because most of the monitored glaciers have no more accumulation area, their observations series are at risk due to their impending extinction, thus requiring a soon replacement.
Contraprestaciones por los servicios financieros del Consulado de México y sus miembros: los fondos extraordinarios para la guerra contra Gran Bretaña, 1779-1783
Authors: Del Valle Pavón Guillermina
Published: October 2015

Nueva España aportó la mayor parte de los recursos que sostuvieron a las fuerzas armadas españolas durante la guerra contra Gran Bretaña que se desarrolló en el Caribe entre 1779 y 1783. En el artículo se analizan las medidas a las que recurrieron las autoridades reales para obtener recursos extraordinarios del Consulado y varios mercaderes de la ciudad de México. Asimismo se exponen algunas de las contraprestaciones que negociaron a cambio de dichos servicios financieros y se plantean diversas hipótesis acerca de los motivos económicos, sociales y políticos que los llevaron a colaborar con el monarca, teniendo en cuenta los negocios que realizaban durante el conflicto bélico y la forma en que eran afectados por la reciente apertura comercial.
How do the Banking Systems of Vietnam, China and India Fare?
Authors: Nguyen Thanh Pham Thien
Published: October 2015

Given that Vietnam, China and India are among the few remaining banking systems which have central bank dependence, state dominance, regulatory restrictions and gradual reforms towards liberalisation, this study examines cost, revenue and profit efficiency and stability of these banking systems. Using DEA Window Analysis, the study found that these banking systems achieved high efficiency levels, with generally increasing efficiency from 1995 to 2011. Cost efficiency was equally driven by technical and allocative efficiencies; revenue efficiency was driven by interest income efficiency more than by non-interest income efficiency; and profit efficiency was equally driven by cost and revenue efficiencies. Furthermore, state banks were found to be more efficient than private banks, but this efficiency gap declined over time. Compared to private banks, state banks appear to have been better at coping with the Asian financial crisis (AFC), but worse at facing the Global financial crisis (GFC). However, banking systems of Vietnam and China were slightly hit by the AFC, while China and India were slightly hit by the GFC.
The Relationship between Organizational Trust and Organizational Silence with Job Satisfaction and Organizational Commitment of the Employees of University
Authors: Fard Parastoo Gashtasebi , Karimi Fariba
Published: October 2015

This study aimed to investigate the structural model between organizational trust and organizational silence with job satisfaction and organizational commitment of the employees of Islamic Azad University of Isfahan, Khorasgan branch. The study method is descriptive-correlation. The study population is the employees of Islamic Azad University of Khorasgan branch (Isfahan) as 340. 180 employees are selected by simple random method and sampling Table (Krejcie & Morgan, 1970). The questionnaires of organizational trust (Ellonen et al., 2008) and organizational silence questionnaires, job satisfaction and organizational commitment (Bouradas & Vakola, 2005). For analysis of study findings, Pearson correlation coefficient and structural equations modeling are applied. The results of study showed that organizational trust had inverse and significant relation with organizational silence and had positive and significant relationship with job satisfaction and organizational commitment. Also, there was an inverse and significant relationship between organizational silence and job satisfaction and organizational commitment. The results of structural equations modeling showed that organizational trust had direct impact on organizational silence (-64) organizational commitment (0.45) and job satisfaction (0.39) and has indirect impact via organizational silence on organizational commitment (0.29) and job satisfaction (0.29). Also, organizational silence had direct impact on organizational commitment and job satisfaction (-45). The model has good conditions in terms of fitness indices and fitness data.
The Effect of IPad on School Preparedness among Preschool Children with Hearing-Impairments
Authors: Turkestani Maryam Hafez
Published: October 2015

With modern technological developments and with the fast expansion of mobile technical equipment, conducting a field study to find out how technology influences various developmental aspects of normal and special needs children at the preschool stage was deemed appropriate and timely hearing impairment. In this study aimed at finding out the effect of iPad on school preparedness among school children with hearing impairment. In this study, the children attended the national kindergarten in Al-Riyadh. The study sample was divided into control (7) and experimental (8) groups. Children in the experimental group used the iPad for 15 weeks. Results showed improvement of the experimental group in all measured areas. The control group, those who did not use the iPads, improved in both their kinetic and social areas. In addition, differences were found between groups on post measurement favoring experimental group. The study recommended conducting more experimental and longitudinal studies to further delve into the effects of using iPads in preschools with children who have impaired hearing.
Sound Velocities and Micellar Behaviour Studies of Dodecyltrimethylammonium Bromide in Aqueous Solutions at 295.15, 302.15 and 309.15 K
Authors: Harun-Al-Rashid Md. , Tofaz Tania , Islam M. , Biswas T.
Published: October 2015

Speed of sound, u, of dodecyltrimethylammonium bromide (DTAB) aqueous solutions has been determined at 295.15, 302.15 and 309.15 K. The speeds of sound, u, data have been used to estimate isentropic compressibility, Ks, apparent molal isentropic compressibility, φk(s), acoustic impedance, Z, molal sound of speed, Rm, and relative association, RA, of DTAB in aqueous solution. These parameters have been interpreted in terms of solute-solute and solute-solvent interactions and micellar behavior of DTAB.
EFL Saudi Students’ Class Emotions and Their Contributions to Their English Achievement at Taif University
Authors: Ismail Nasrah M.
Published: October 2015

This paper investigates class academic emotions of anger, anxiety, enjoyment, hope, hopelessness, pride, boredom and shame in the academic situation and their contributions to Saudi EFL students’ English achievement. It also strives to find if there are any differences in class emotions and achievement according gender and streams (science and humanities). The sample consists of 315 (177 males & 138 females) university students. The Pekrun, Goetz, Titz and Perry (2002) class-related emotions scale was used to determine class emotions of students. The findings revealed that there are no differences between science and humanities (M = 22.763, SD = 8.118) in achievement and class emotions except in boredom in favour of science stream. The results also indicated that there were no differences between males and females in class emotions except in the enjoyment in favour of females. It also revealed that there were significant differences between males and females in English achievement in favour of females. On the other hand, it was found that emotions explained 65.8 % in variance of the students’ academic achievement. Furthermore, the findings have implications for students, teachers, and curriculum developers who are to develop a curriculum well-suited with the needs of language learners.