bluuebunny/crossref_metadata_2025_split huggingface dataset:
Massive Elliptical Galaxies: BH Scouring or a Bottom-Heavy IMF?
Authors: Thomas Jens , Saglia Roberto , Bender Ralf , Erwin Peter , Fabricius Maximilian 
Published: April 2015

AbstractWe present indirect constraints on the stellar initial-mass-function (IMF) in nine massive elliptical galaxies with σ ≈ 300 km/s, via a comparison of dynamical and stellar-population based stellar masses. We use adaptive-optics assisted, high resolution kinematical data from the SINFONI Search for Supermassive Black Holes that allow us to constrain the dynamical stellar mass-to-light ratio in the very centre of each galaxy. Hence we measure the IMF in a galaxy region where the stellar mass dominates over dark matter, minimising any potential degeneracy between the two mass components. In six of our galaxies – those which have depleted stellar cores – we find an IMF consistent with the one measured in the Milky-Way via direct star counts. The three remaining, power-law galaxies have instead stellar masses about a factor of two times larger than expected from a Milky-Way type IMF, indicating either a more bottom-heavy IMF (like, e.g., the Salpeter IMF) or a dark-matter distribution that is degenerate with the stellar mass down to the very centres of these galaxies. The bottom-light IMF in our core galaxies is surprising in view of previous studies that suggested a systematic IMF variation where early-type galaxies with σ ≈ 300 km/s have a Salpeter or even more dwarf-dominated IMF. Core galaxies are particularly important since their unique central orbital structure offers an independent crosscheck for the dynamical models. Our models with a bottom-light IMF are consistent with the distribution of orbits predicted by SMBH-binary core-formation models. This indicates that spatially well resolved central kinematical data are important for determining unbiased dynamical stellar mass-to-light ratios. Our results imply either that the IMF in massive galaxies varies over a wider range than previously anticipated, and is not the same in core and power-law ellipticals, or else that there are systematic variations in the distribution of dark matter among massive early-type galaxies.
The Stellar Mass of M31 as inferred by the Andromeda Optical & Infrared Disk Survey
Authors: Sick Jonathan , Courteau Stephane , Cuillandre Jean-Charles , Dalcanton Julianne , de Jong Roelof , McDonald Michael , Simard Dana , Brent Tully R. 
Published: April 2015

AbstractOur proximity and external vantage point make M31 an ideal testbed for understanding the structure of spiral galaxies. The Andromeda Optical and Infrared Disk Survey (ANDROIDS) has mapped M31's bulge and disk out to R=40 kpc in ugriJKs bands with CFHT using a careful sky calibration. We use Bayesian modelling of the optical-infrared spectral energy distribution (SED) to estimate profiles of M31's stellar populations and mass along the major axis. This analysis provides evidence for inside-out disk formation and a declining metallicity gradient. M31's i-band mass-to-light ratio (M/Li*) decreases from 0.5 dex in the bulge to ~ 0.2 dex at 40 kpc. The best-constrained stellar population models use the full ugriJKs SED but are also consistent with optical-only fits. Therefore, while NIR data can be successfully modelled with modern stellar population synthesis, NIR data do not provide additional constraints in this application. Fits to the gi-SED alone yield M/Li* that are systematically lower than the full SED fit by 0.1 dex. This is still smaller than the 0.3 dex scatter amongst different relations for M/Li via g – i colour found in the literature. We advocate a stellar mass of M*(30 kpc) = 10.3+2.3-1.7 × 1010 M⊙ for the M31 bulge and disk.
The Secret Life of Galaxies
Authors: Dressler Alan , Abramson Louis 
Published: April 2015

AbstractWe have learned much about galaxy evolution since z = 2, and something to even higher redshifts. How can it be that we know so little about! the star formation histories (SFHs) of individual galaxies? Although great progress has been made accumulating huge samples with only rudimentary properties, progress in galaxy evolution means connecting what we've learned to detailed measurements of the life-histories of specific –- not just representative –- systems.
Kinematic Evolution of Field and Cluster Spiral Galaxies
Authors: Ziegler Bodo L. , Böhm Asmus 
Published: April 2015

AbstractWe investigate the evolution of the Tully–Fisher relation out to z = 1 with 137 emission-line galaxies in the field that display a regular rotation curve. They follow a linear trend with lookback time being on average brighter by 1.1 Bmag and 60% smaller at z = 1. For a subsample of 48 objects with very regular gas kinematics and stellar structure we derive a TF scatter of 1.15mag, which is two times larger than local samples exhibit. This is probably due to modest variations in their star formation history and chemical enrichment.In another study of 96 members of Abell 901/902 at z = 0.17 and 86 field galaxies with similar redshifts we find a difference in the TFR of 0.42mag in the B-band but no significant difference in stellar mass. Comparing specifically red spirals with blue ones in the cluster, the former are fainter on average by 0.35 Bmag and have 15% lower stellar masses. This is probably due to star formation quenching caused by ram-pressure in the cluster environment. Evidence for this scenario comes from strong distortions of the gas disk of red spirals that have at the same time a very regular stellar disk structure.
miR-26a and miR-384-5p are required for LTP maintenance and spine enlargement
Authors: Gu Qin-Hua , Yu Danni , Hu Zhonghua , Liu Xing , Yang Yanqin , Luo Yan , Zhu Jun , Li Zheng 
Published: April 2015

AbstractLong-term potentiation (LTP) is a form of synaptic plasticity that results in enhanced synaptic strength. It is associated with the formation and enlargement of dendritic spines—tiny protrusions accommodating excitatory synapses. Both LTP and spine remodelling are crucial for brain development, cognition and the pathophysiology of neurological disorders. The role of microRNAs (miRNAs) in the maintenance of LTP, however, is not well understood. Using next-generation sequencing to profile miRNA transcriptomes, we demonstrate that miR-26a and miR-384-5p specifically affect the maintenance, but not induction, of LTP and different stages of spine enlargement by regulating the expression of RSK3. Using bioinformatics, we also examine the global effects of miRNA transcriptome changes during LTP on gene expression and cellular activities. This study reveals a novel miRNA-mediated mechanism for gene-specific regulation of translation in LTP, identifies two miRNAs required for long-lasting synaptic and spine plasticity and presents a catalogue of candidate ‘LTP miRNAs’.
Plant macrofossil evidence for an early onset of the Holocene summer thermal maximum in northernmost Europe
Authors: Väliranta M. , Salonen J. S. , Heikkilä M. , Amon L. , Helmens K. , Klimaschewski A. , Kuhry P. , Kultti S. , Poska A. , Shala S. , Veski S. , Birks H. H. 
Published: April 2015

AbstractHolocene summer temperature reconstructions from northern Europe based on sedimentary pollen records suggest an onset of peak summer warmth around 9,000 years ago. However, pollen-based temperature reconstructions are largely driven by changes in the proportions of tree taxa, and thus the early-Holocene warming signal may be delayed due to the geographical disequilibrium between climate and tree populations. Here we show that quantitative summer-temperature estimates in northern Europe based on macrofossils of aquatic plants are in many cases ca. 2 °C warmer in the early Holocene (11,700–7,500 years ago) than reconstructions based on pollen data. When the lag in potential tree establishment becomes imperceptible in the mid-Holocene (7,500 years ago), the reconstructed temperatures converge at all study sites. We demonstrate that aquatic plant macrofossil records can provide additional and informative insights into early-Holocene temperature evolution in northernmost Europe and suggest further validation of early post-glacial climate development based on multi-proxy data syntheses.
Liquid crystals for organic thin-film transistors
Authors: Iino Hiroaki , Usui Takayuki , Hanna Jun-ichi 
Published: April 2015

AbstractCrystalline thin films of organic semiconductors are a good candidate for field effect transistor (FET) materials in printed electronics. However, there are currently two main problems, which are associated with inhomogeneity and poor thermal durability of these films. Here we report that liquid crystalline materials exhibiting a highly ordered liquid crystal phase of smectic E (SmE) can solve both these problems. We design a SmE liquid crystalline material, 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10), for FETs and synthesize it. This material provides uniform and molecularly flat polycrystalline thin films reproducibly when SmE precursor thin films are crystallized, and also exhibits high durability of films up to 200 °C. In addition, the mobility of FETs is dramatically enhanced by about one order of magnitude (over 10 cm2 V−1 s−1) after thermal annealing at 120 °C in bottom-gate-bottom-contact FETs. We anticipate the use of SmE liquid crystals in solution-processed FETs may help overcome upcoming difficulties with novel technologies for printed electronics.
Pharmacologically blocking p53-dependent apoptosis protects intestinal stem cells and mice from radiation
Authors: Wang Xinwei , Wei Liang , Cramer Julie M. , Leibowitz Brian J. , Judge Colleen , Epperly Michael , Greenberger Joel , Wang Fengchao , Li Linheng , Stelzner Matthias G. , Dunn James C. Y. , Martin Martin G. , Lagasse Eric , Zhang Lin , Yu Jian 
Published: April 2015

AbstractExposure to high levels of ionizing radiation (IR) leads to debilitating and dose-limiting gastrointestinal (GI) toxicity. Using three-dimensional mouse crypt culture, we demonstrated that p53 target PUMA mediates radiation-induced apoptosis via a cell-intrinsic mechanism and identified the GSK-3 inhibitor CHIR99021 as a potent radioprotector. CHIR99021 treatment improved Lgr5+ cell survival and crypt regeneration after radiation in culture and mice. CHIR99021 treatment specifically blocked apoptosis and PUMA induction and K120 acetylation of p53 mediated by acetyl-transferase Tip60, while it had no effect on p53 stabilization, phosphorylation or p21 induction. CHIR99021 also protected human intestinal cultures from radiation by PUMA but not p21 suppression. These results demonstrate that p53 posttranslational modifications play a key role in the pathological and apoptotic response of the intestinal stem cells to radiation and can be targeted pharmacologically.
Classification of foodborne pathogens using near infrared (NIR) laser scatter imaging system with multivariate calibration
Authors: Pan Wenxiu , Zhao Jiewen , Chen Quansheng 
Published: April 2015

AbstractAn optical sensor system, namely NIR laser scatter imaging system, was developed for rapid and noninvasive classification of foodborne pathogens. This developed system was used for images acquisition. The current study is focused on exploring the potential of this system combined with multivariate calibrations in classifying three categories of popular bacteria. Initially, normalization and Zernike moments extraction were performed and the resultant translation, scale and rotation invariances were applied as the characteristic variables for subsequent discriminant analysis. Both linear (LDA, KNN and PLSDA) and nonlinear (BPANN, SVM and OSELM) pattern recognition methods were employed comparatively for modeling and optimized by cross validation. Experimental results showed that the performances of nonlinear tools were superior to those of linear tools, especially for OSELM model with 95% discrimination rate in the prediction set. The overall results showed that it is extremely feasible for rapid and noninvasive classifying foodborne pathogens using this developed system combined with appropriate multivariate calibration.
Complete rat spinal cord transection as a faithful model of spinal cord injury for translational cell transplantation
Authors: Lukovic Dunja , Moreno-Manzano Victoria , Lopez-Mocholi Eric , Rodriguez-Jiménez Francisco Javier , Jendelova Pavla , Sykova Eva , Oria Marc , Stojkovic Miodrag , Erceg Slaven 
Published: April 2015

AbstractSpinal cord injury (SCI) results in neural loss and consequently motor and sensory impairment below the injury. There are currently no effective therapies for the treatment of traumatic SCI in humans. Various animal models have been developed to mimic human SCI. Widely used animal models of SCI are complete or partial transection or experimental contusion and compression, with both bearing controversy as to which one more appropriately reproduces the human SCI functional consequences. Here we present in details the widely used procedure of complete spinal cord transection as a faithful animal model to investigate neural and functional repair of the damaged tissue by exogenous human transplanted cells. This injury model offers the advantage of complete damage to a spinal cord at a defined place and time, is relatively simple to standardize and is highly reproducible.
Exposure Medium: Key in Identifying Free Ag+ as the Exclusive Species of Silver Nanoparticles with Acute Toxicity to Daphnia magna
Authors: Shen Mo-Hai , Zhou Xiao-Xia , Yang Xiao-Ya , Chao Jing-Bo , Liu Rui , Liu Jing-Fu 
Published: April 2015

AbstractIt is still not very clear what roles the various Ag species play in the toxicity of silver nanoparticles (AgNPs). In this study, we found that traditional exposure media result in uncontrollable but consistent physicochemical transformation of AgNPs, causing artifacts in determination of median lethal concentration (LC50) and hindering the identification of Ag species responsible for the acute toxicity of AgNPs to Daphnia magna. This obstacle was overcome by using 8 h exposure in 0.1 mmol L−1 NaNO3 medium, in which we measured the 8-h LC50 of seven AgNPs with different sizes and coatings and determined the concentrations of various Ag species. The LC50 as free Ag+ of the seven AgNPs (0.37–0.44 μg L−1) agreed very well with that of AgNO3 (0.40 μg L−1) and showed the lowest value compared to that as total Ag, total Ag+ and dissolved Ag, demonstrating free Ag+ is exclusively responsible for the acute toxicity of AgNPs to D. magna, while other Ag species in AgNPs have no contribution to the acute toxicity. Our results demonstrated the great importance of developing appropriate exposure media for evaluating risk of nanomaterials.
Exact Periodic Wave Solution of Extended (2+1)-Dimensional Shallow
Water Wave Equation with Generalized
D
-operators*
Authors: Dong Huan-He , Zhang Yan-Feng 
Published: April 2015

Abstract
With the aid of binary Bell polynomial and a general Riemann theta function, we
introduce how to obtain the exact periodic wave solutions by applying the
generalized Dp̄-operators in term of the Hirota direct method
when the appropriate value of p̄ is determined. Furthermore, the
resulting approach is applied to solve the extended (2+1)-dimensional
Shallow Water Wave equation, and the periodic wave solution is obtained and
reduced to soliton solution via asymptotic analysis.
Analytical Study on Propagation Dynamics of Optical Beam in Parity-Time Symmetric Optical Couplers*
Authors: Zhou Zheng , Zhu Bo , Zhang Li-Juan 
Published: April 2015

Abstract
We present exact analytical solutions to parity-time (PT) symmetric optical system describing light transport in PT-symmetric optical couplers. We show that light intensity oscillates periodically between two waveguides for unbroken PT-symmetric phase, whereas light always leaves the system from the waveguide experiencing gain when light is initially input at either waveguide experiencing gain or waveguide experiencing loss for broken PT-symmetric phase. These analytical results agree with the recent experimental observation reported by Rüter et al. [Nat. Phys. 6 (2010) 192]. Besides, we present a scheme for manipulating PT symmetry by applying a periodic modulation. Our results provide an efficient way to control light propagation in periodically modulated PT-symmetric system by tuning the modulation amplitude and frequency.
Bosonized Supersymmetric Sawada–Kotera Equations: Symmetries and Exact Solutions*
Authors: Liu Ping , Zeng Bao-Qing , Liu Li-Ming 
Published: April 2015

Abstract
The Bosonized Supersymmetric Sawada–Kotera (BSSK) system is constructed by applying bosonization method to a Supersymmetric Sawada–Kotera system in this paper. The symmetries on the BSSK equations are researched and the calculation shows that the BSSK equations are invariant under the scaling transformations, the space-time translations and Galilean boosts. The one-parameter invariant subgroups and the corresponding invariant solutions are researched for the BSSK equations. Four types of reduction equations and similarity solutions are proposed. Period Cnoidal wave solutions, dark solitary wave solutions and bright solitary wave solutions of the BSSK equations are demonstrated and some evolution curves of the exact solutions are figured out.
The Saturation of Several Universal Inequalities in Information-Processing*
Authors: Zhang Lin , Wu Jun-De , Fei Shao-Ming 
Published: April 2015

Abstract
In this paper, we characterize the saturation of four universal inequalities in quantum information theory, including a variant version of strong subadditivity inequality for von Neumann entropy, the coherent information inequality, the Holevo quantity, and average entropy inequalities. These results shed new light on quantum information inequalities.
Analytic Expression of Geometric Discord in Arbitrary Mixture of any Two Bi-qubit Product Pure States*
Authors: Xie Chuan-Mei , Liu Yi-Min , Xing Hang , Zhang Zhan-Jun 
Published: April 2015

Abstract
Quantum correlations in a family of states comprising any mixture of a pair of arbitrary bi-qubit product pure states are studied by employing geometric discord [Phys. Rev. Lett. 105 (2010) 190502] as the quantifier. First, the inherent symmetry in the family of states about local unitary transformations is revealed. Then, the analytic expression of geometric discords in the states is worked out. Some concrete discussions and analyses on the captured geometric discords are made so that their distinct features are exposed. It is found that, the more averagely the two bi-qubit product states are mixed, the bigger geometric discord the mixed state owns. Moreover, the monotonic relationships of geometric discord with different parameters are revealed.
Modified Holographic Ricci Dark Energy in Chameleon Brans–Dicke Cosmology and Its Thermodynamic Consequence*
Authors: Jawad A. , Chattopadhyay S. , Bhattacharya S. , Pasqua A. 
Published: April 2015

Abstract
The objective of this paper is to discuss the Chameleon Brans–Dicke gravity with non-minimally matter coupling of scalar field. We take modified Holographic Ricci dark energy model in this gravity with its energy density in interaction with energy density of cold dark matter. We assume power-law ansatz for scale factor and scalar field to discuss potential as well as coupling functions in the evolving universe. These reconstructed functions are plotted versus scalar field and time for different values of power component of scale factor n. We observe that potential and coupling functions represent increasing behavior, in particular, consistent results for a specific value of n. Finally, we have examined validity of the generalized second law of thermodynamics and we have observed its validity for all values of n.
Reanalysis of the Z

c
(4020), Z

c
(4025), Z(4050) and Z(4250) as Tetraquark States with QCD Sum Rules*
Authors: Wang Zhi-Gang 
Published: April 2015

Abstract
In this article, we calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the Cγμ — Cγν type scalar, axial-vector and tensor tetraquark states in details with the QCD sum rules. In calculations, we use the formula

to determine the energy scales of the QCD spectral densities. The predictions

M

J
=
2

=

(

4.02

-
0.09

+
0.09

)

GeV
,

M

J
=
1

=

(

4.02

-
0.08

+
0.07

)

GeV

favor assigning the Zc(4020) and Zc(4025) as the JPC = 1+− or 2++ diquark-antidiquark type tetraquark states, while the prediction

M

J
=
0

=

(

3.85

-
0.09

+
0.15

)

GeV

disfavors assigning the Z(4050) and Z(4250) as the JPC = 0++ diquark-antidiquark type tetraquark states. Furthermore, we discuss the strong decays of the 0++, 1+−, 2++ diquark-antidiquark type tetraquark states in details.
Numerical Analysis of Electromagnetic Fields in Multiscale Model*
Authors: Ma Ji , Fang Guang-You , Ji Yi-Cai 
Published: April 2015

Abstract
Modeling technique for electromagnetic fields excited by antennas is an important topic in computational electromagnetics, which is concerned with the numerical solution of Maxwell's equations. In this paper, a novel hybrid technique that combines method of moments (MoM) with finite-difference time-domain (FDTD) method is presented to handle the problem. This approach employed Huygen's principle to realize the hybridization of the two classical numerical algorithms. For wideband electromagnetic data, the interpolation scheme is used in the MoM based on the dyadic Green's function. On the other hand, with the help of equivalence principle, the scattered electric and magnetic fields on the Huygen's surface calculated by MoM are taken as the sources for FDTD. Therefore, the electromagnetic fields in the environment can be obtained by employing finite-difference time-domain method. Finally, numerical results show the validity of the proposed technique by analyzing two canonical samples.
Percolation Phase Transitions from Second Order to First Order in Random Networks*
Authors: Jia Xiao , Hong Jin-Song , Yang Hong-Chun , Yang Chun , Fu Chuan-Ji , Hu Jian-Quan , Shi Xiao-Hong 
Published: April 2015

Abstract
We investigate a percolation process where an additional parameter q is used to interpolate between the classical Erdös–Rényi (ER) network model and the smallest cluster (SC) model. This model becomes the ER network at q = 1, which is characterized by a robust second order phase transition. When q = 0, this model recovers to the SC model which exhibits a first order phase transition. To study how the percolation phase transition changes from second order to first order with the decrease of the value of q from 1 to 0, the numerical simulations study the final vanishing moment of the each existing cluster except the N-cluster in the percolation process. For the continuous phase transition, it is shown that the tail of the graph of the final vanishing moment has the characteristic of the convexity. While for the discontinuous phase transition, the graph of the final vanishing moment possesses the characteristic of the concavity. Just before the critical point, it is found that the ratio between the maximum of the sequential vanishing clusters sizes and the network size N can be used to decide the phase transition type. We show that when the ratio is larger than or equal to zero in the thermodynamic limit, the percolation phase transition is first or second order respectively. For our model, the numerical simulations indicate that there exists a tricritical point qc which is estimated to be between 0.2 < qc < 0.25 separating the two phase transition types.