bluuebunny/crossref_metadata_2025_split huggingface dataset:
A generalized Reynolds analogy for compressible wall-bounded turbulent flows
Authors: Zhang You-Sheng , Bi Wei-Tao , Hussain Fazle , She Zhen-Su 
Published: December 2013

AbstractA generalized Reynolds analogy (GRA) is proposed for compressible wall-bounded turbulent flows (CWTFs) and validated by direct numerical simulations. By introducing a general recovery factor, a similarity between the Reynolds-averaged momentum and energy equations is established for the canonical CWTFs (i.e. pipes, channels, and flat-plate boundary layers that meet the quasi-one-dimensional flow approximation), independent of Prandtl number, wall temperature, Mach number, Reynolds number, and pressure gradient. This similarity and the relationships between temperature and velocity fields constitute the GRA. The GRA relationship between the mean temperature and the mean velocity takes the same quadratic form as Walz’s equation, with the adiabatic recovery factor replaced by the general recovery factor, and extends the validity of the latter to diabatic compressible turbulent boundary layers and channel/pipe flows. It also derives Duan & Martín’s (J. Fluid Mech., vol. 684, 2011, pp. 25–59) empirical relation for flows at different physical conditions (wall temperature, Mach number, enthalpy condition, surface catalysis, etc.). Several key parameters besides the general recovery factor emerge in the GRA. An effective turbulent Prandtl number is shown to be the reason for the parabolic profile of mean temperature versus mean velocity, and it approximates unity in the fully turbulent region. A dimensionless wall temperature, that we call the diabatic parameter, characterizes the wall-temperature effects in diabatic flows. The GRA also extends the analysis to the fluctuation fields. It recovers the modified strong Reynolds analogy proposed by Huang, Coleman & Bradshaw (J. Fluid Mech., vol. 305, 1995, pp. 185–218) and explains the variation of the temperature–velocity correlation coefficient with wall temperature. Thus, the GRA unveils a generalized similarity principle behind the complex nonlinear coupling between the thermal and velocity fields of CWTFs.
Lateral migration of a capsule in plane shear near a wall
Authors: Singh Rajesh Kumar , Li Xiaoyi , Sarkar Kausik 
Published: December 2013

AbstractThe migration of a capsule enclosed by an elastic membrane in a wall-bounded linear shear is investigated using a front-tracking method. A detailed comparison with the migration of a viscous drop is presented varying the capillary number (in the case of a capsule, the elastic capillary number) and the viscosity ratio. In both cases, the deformation breaks the flow reversal symmetry and makes them migrate away from the wall. They quickly go through a transient evolution to eventually reach a quasi-steady state where the dynamics becomes independent of the initial position and only depends on the wall distance. Previous analytical theories predicted that for a viscous drop, in the quasi-steady state, the migration and slip velocities scale approximately with the square of the inverse of the drop–wall separation, whereas the drop deformation scales as the inverse cube of the separation. These power law relations are shown to hold for a capsule as well. The deformation and inclination angle of the capsule and the drop at the same wall separation show a crossover in their variation with the capillary number: the capsule shows a steeper variation than that of the drop for smaller capillary numbers and slower variation than the drop for larger capillary numbers. Using the Green’s function of Stokes flow, a semi-analytic theory is presented to show that the far-field stresslet that causes the migration has two distinct contributions from the interfacial stresses and the viscosity ratio, with competing effects between the two defining the dynamics. It predicts the scaling of the migration velocity with the capsule–wall separation, however, matching with the simulated result very well only away from the wall. A phenomenological correlation for the migration velocity as a function of elastic capillary number, wall distance and viscosity ratio is developed using the simulation results. The effects of different membrane hyperelastic constitutive equations – neo-Hookean, Evans–Skalak, and Skalak – are briefly investigated to show that the behaviour remains similar for different equations.
Linking hypotheses underlying Class A and Class B methods
Authors: MORGAN M.J. , MELMOTH D. , SOLOMON J.A. 
Published: December 2013

AbstractClass A psychophysical observations are based on the linking hypothesis that perceptually distinguishable stimuli must correspond to different brain events. Class B observations are related to the appearance of stimuli not their discriminability. There is no clear linking hypothesis underlying Class B observations, but they are necessary for studying the effects of context on appearance, including a large class of phenomena known as “illusions.” Class B observations are necessarily measures of observer bias (Fechner’s “constant error”) as opposed to Class A measures of sensitivity (Fechner’s “variable error”). It is therefore important that Class B observations distinguish between response biases, decisional biases, and perceptual biases. This review argues that the commonly used method of single stimuli fails to do this, and that multiple-alternative forced choice (mAFC) methods can do a better job, particularly if combined with a roving pedestal.
Post-natal oogenesis: a concept for controversy that intensified during the last decade
Authors: Esmaeilian Yashar , Atalay Arzu , Erdemli Esra 
Published: December 2013

SummaryFor decades, scientists have considered that female mammals are born with a lifetime reserve of oocytes in the ovary, irrevocably fated to decline after birth. However, controversy in the matter of the possible presence of oocytes and granulosa cells that originate from stem cells in the adult mammalian ovaries has been expanded. The restricted supply of oocytes in adult female mammals has been disputed in recent years by supporters of neo-oogenesis, who claim that germline stem cells (GSCs) exist in the ovarian surface epithelium (OSE) or the bone marrow (BM). Differentiation of ovarian stem cells (OSCs) into oocytes, fibroblast-like cells, granulosa phenotype, neural and mesenchymal type cells and generation of germ cells from OSCs under the contribution of an OSC niche that consists of immune system-related cells and hormonal signalling has been claimed. Although these arguments have met with intense suspicion, their confirmation would necessitate the revision of the current classic knowledge of female reproductive biology.
Polyphenols, tannins and caffeine content and antioxidant activity of green teas coming from organic and non-organic production
Authors: Kazimierczak Renata , Hallmann Ewelina , Rusaczonek Anna , Rembiałkowska Ewa 
Published: December 2013

AbstractAmong infusions of green teabags and leafy green teas from organic and non-organic production systems we measured and compared the content of phenolic acids, flavonols and total polyphenols by spectrophotometry, the content of tannins by titration and the content of caffeine by high-performance liquid chromatography (HPLC). In addition, the antioxidant activity of the infusions was determined by spectrophotometry. The results obtained have shown that organic teas contained significantly more flavonols and tannins. However, the content of phenolic acids was higher in non-organic teas. The teas from organic and non-organic production did not differ in terms of total polyphenol content and antioxidant activity. There were no differences in leaf teas in relation to the teabags in contents of phenolic acids, tannins and total polyphenols. Organic teas had higher content of catechin C than the non-organic ones, but at the same time non-organic teas had more epigallocatechin 3-gallate (EGCG) in comparison to organic teas. Epigallocatechin (EGC) and epicatechin (EC) were not found to be different between the two groups of tea. Catechin was found to be significantly higher in teabags, while the EGCG was higher in leaf teas. The reason for this may be the oxidation of teabags, which have a greater exposed surface area. There was no appreciable effect of the form of tea on the content of tannins, caffeine, flavonols, phenolic acids, total polyphenols, EGC and EC as well as the antioxidant activity of the tea infusions examined.
Computational Assay of H7N9 Influenza Neuraminidase Reveals R292K Mutation Reduces Drug Binding Affinity
Authors: Woods Christopher J. , Malaisree Maturos , Long Ben , McIntosh-Smith Simon , Mulholland Adrian J. 
Published: December 2013

AbstractThe emergence of a novel H7N9 avian influenza that infects humans is a serious cause for concern. Of the genome sequences of H7N9 neuraminidase available, one contains a substitution of arginine to lysine at position 292, suggesting a potential for reduced drug binding efficacy. We have performed molecular dynamics simulations of oseltamivir, zanamivir and peramivir bound to H7N9, H7N9-R292K and a structurally related H11N9 neuraminidase. They show that H7N9 neuraminidase is structurally homologous to H11N9, binding the drugs in identical modes. The simulations reveal that the R292K mutation disrupts drug binding in H7N9 in a comparable manner to that observed experimentally for H11N9-R292K. Absolute binding free energy calculations with the WaterSwap method confirm a reduction in binding affinity. This indicates that the efficacy of antiviral drugs against H7N9-R292K will be reduced. Simulations can assist in predicting disruption of binding caused by mutations in neuraminidase, thereby providing a computational ‘assay.’
Sequestration of the abrin A chain to the nucleus by BASP1 increases the resistance of cells to abrin toxicity
Authors: Gadadhar Sudarshan , Bora Namrata , Tiwari Vinita , Karande Anjali A. 
Published: December 2013

Abrin, a type II ribosome-inactivating protein, comprises A and B subunits wherein the A subunit harbours toxin activity and the B subunit has a galactose-specific lectin activity. The entry of the protein inside the cell is through the binding of the B chain to cell surface glycoproteins followed by receptor-mediated endocytosis and retrograde transport. A previous study from our laboratory showed that different cell lines exhibited differences of as great as ~200-fold in abrin toxicity, prompting the present study to compare the trafficking of the toxin within cells. Observations made in this regard revealed that the abrin A chain, after being released into the cytosol, is sequestered into the nucleus through interaction with a cellular protein of ~25 kDa, BASP1 (brain acid-soluble protein 1). The nuclear localization of the A chain is seen predominantly in cells that are less sensitive to abrin toxicity and dependent on the levels of BASP1 in cells. The sequestration by BASP1 renders cells increasingly resistant to the inhibition of protein synthesis by abrin and the nucleus act as a sink to overcome cellular stress induced by the toxin.
Compact frequency selective surface for polarisation transform
Authors: Morrow I.L. , Thomas P. 
Published: December 2013

The polarisation transforming properties of a compact frequency selective surface (FSS) are reported. Although known designs made with meander lines employ several cascaded surfaces with many interconnects, the design methodology presented uses a single planar surface of very closely arrayed metallic meander lines impedance loaded with rectangular metal patches. A simulated axial ratio of ≤ −3 dB was obtained over a 40% bandwidth, from 2.10 to 3.2 GHz and optimised for 2.75 GHz. Simulation of normal and oblique incidence in both planes of polarisation shows a ±30° wide range of angles of incidence for polariser performance. A unit cell of the FSS circular polariser is λo/12 in size at the optimised operating frequency. The FSS circular polariser was manufactured and attached to a horn antenna aperture and measurement confirmed axial ratio performance.
Power amplifier non‐linearity treatment with distorted constellation estimation and demodulation for 60 GHz single‐carrier frequency‐domain equalisation transmission
Authors: Zhang Changming , Xiao Zhenyu , Gao Bo , Su Li , Jin Depeng 
Published: December 2013

Power amplifier (PA) non‐linearity is extremely significant for 60 GHz millimetre‐wave communications, which distorts signal constellation seriously. In dealing with this problem, the commonly used digital predistortion (DPD) becomes unaffordable for 60 GHz systems in both power consumption and price. This study proposes to handle PA non‐linearity with distorted constellation (DCS) estimation and demodulation for 60 GHz systems with single‐carrier frequency‐domain equalisation transmission, which has a low implementation cost. Employing the least‐square (LS) algorithm, the DCS is estimated both before and after equalisation, where LS after equalisation has a lower computational complexity than LS before equalisation. Subsequently, the estimated DCS, instead of the standard constellation, is used as a criterion for demodulation, which is shown to achieve a significant improvement on the symbol‐error‐rate (SER) performance, especially when the non‐linear distortion is severe. Moreover, compared with DPD, the proposed method achieves a better SER performance and behaves more robustly in the low range of input power back‐off (IBO), whereas achieving a close SER performance in the high‐IBO range.
Field operational testing for safety improvement of freight trains using wireless monitoring by sensor network
Authors: Grudén Mathias , Hinnemo Malkolm , Dancila Dragos , Zherdev Filip , Edvinsson Nils , Brunberg Kjell , Andersson Lennart , Byström Roger , Rydberg Anders 
Published: December 2013

Today, the majority of wagon failures on railroad systems are because of the poor maintenance of ball bearings, which causes emergent stops and delays. The existing stationary detectors, lack in predicting failures which cause troubles in scheduling maintenance. During the fall of 2011, a trial was performed by applying a wireless sensor network (WSN) aboard a train wagon with the objective to demonstrate a proof of concept for monitoring the temperature of ball bearings aboard the train wagon. This trial investigates several key aspects when applying sensor networks such as radio wave propagation, energy scavenging and performance of the WSN aboard the wagon. Two wireless links were used in the WSN. The aboard network communicates at 2.45 GHz, and the external communication is an 868 MHz radio frequency identification radio link. Since the energy in the WSN node is limited, appropriate energy scavenging devices are also presented and evaluated in a lab environment. Effort has been made to overcome these problems. The energy consumption in the network is still a problem; the most promising energy scavenging technique is piezoelectric harvesting by vibrations, which in the experiments scavenged 2.32 mW.
Mechanisms underlying subunit independence in pyramidal neuron dendrites
Authors: Behabadi Bardia F. , Mel Bartlett W. 
Published: December 2013

Significance
Historically, neurons were thought to collect synaptic currents from across their dendritic trees and passively conduct them to the soma where action potentials (APs) are generated. More recent studies have shown that dendrites can generate local spikes and thus may function as independent computational subunits. It remains unknown, however, how dendrites can maintain the integrity and separateness of their local computations, which depend on voltage, despite the repeated synchronization of dendritic potentials by back-propagating somatic APs. This modeling study identifies three biophysical specializations that allow dendrites to remain functionally independent in a firing neuron, one of which is the somatic spiking mechanism itself. Our results suggest that a major class of neurons has been optimized for subunitized computation.
Operator ideals and assembly maps in 𝐾-theory
Authors: Cortiñas Guillermo , Tartaglia Gisela 
Published: December 2013

Let

B

\mathcal {B}

be the ring of bounded operators in a complex, separable Hilbert space. For

p
>
0

p>0

consider the Schatten ideal

L

p

\mathcal {L}^p

consisting of those operators whose sequence of singular values is

p
p

-summable; put

S

=

⋃
p

L

p

\mathcal {S}=\bigcup _p\mathcal {L}^p

. Let

G
G

be a group and

V

c
y
c

\mathcal {V}cyc

the family of virtually cyclic subgroups. Guoliang Yu proved that the

K
K

-theory assembly map
\[

H
∗
G

(

E

(
G
,

V

c
y
c
)
,
K
(

S

)
)
→

K
∗

(

S

[
G
]
)

H_*^G(\mathcal {E}(G,\mathcal {V}cyc),K(\mathcal {S}))\to K_*(\mathcal {S}[G])

\]
is rationally injective. His proof involves the construction of a certain Chern character tailored to work with coefficients

S

\mathcal {S}

and the use of some results about algebraic

K
K

-theory of operator ideals and about controlled topology and coarse geometry. In this paper we give a different proof of Yu’s result. Our proof uses the usual Chern character to cyclic homology. Like Yu’s, it relies on results on algebraic

K
K

-theory of operator ideals, but no controlled topology or coarse geometry techniques are used. We formulate the result in terms of homotopy

K
K

-theory. We prove that the rational assembly map
\[

H
∗
G

(

E

(
G
,

F

i
n
)
,
K
H
(

L

p

)
)
⊗

Q

→
K

H
∗

(

L

p

[
G
]
)
⊗

Q

H_*^G(\mathcal {E}(G,\mathcal {F}in),KH(\mathcal {L}^p))\otimes \mathbb {Q}\to KH_*(\mathcal {L} ^p[G])\otimes \mathbb {Q}

\]
is injective. We show that the latter map is equivalent to the assembly map considered by Yu, and thus obtain his result as a corollary.
Agricultural Rodent Control Using Barn Owls: Is It Profitable?
Authors: Kan Iddo , Motro Yoav , Horvitz Nir , Kimhi Ayal , Leshem Yossi , Yom-Tov Yoram , Nathan Ran 
Published: December 2013

AbstractWe develop a model to evaluate the profitability of controlling rodent damage by placing barn owl nesting boxes in agricultural areas. The model incorporates the spatial patterns of barn owl predation pressure on rodents, and the impact of this predation pressure on nesting choices and agricultural output. We apply the model to data collected in Israel and find the installation of nesting boxes profitable. While this finding indicates that economic policy instruments to enhance the adoption of this biological control method are redundant, it does support stricter regulations on rodent control using rodenticides.
MiR-568 inhibits the activation and function of CD4+ T cells and Treg cells by targeting NFAT5
Authors: Li Wei , Kong Ling-bo , Li Jun-Tang , Guo Zhang-Yan , Xue Qian , Yang Tao , Meng Yan-Ling , Jin Bo-Quan , Wen Wei-Hong , Yang An-Gang 
Published: December 2013

Abstract
CD4+ T cells play critical roles in orchestrating adaptive immune responses. Their activation and proliferation are critical steps that occur before they execute their biological functions. Despite the important role of this process, the underlying molecular events are not fully understood. MicroRNAs (miRNAs) have been shown to play important roles in lymphocyte development and function. However, the miRNAs that regulate T-cell differentiation, activation and proliferation are still largely unknown. In our previous study, using a miRNA array, we found that several miRNAs (including miR-202, 33b, 181c, 568 and 576) are differentially expressed between resting and activated CD4+ T cells. In this study, we focused on the function of miR-568 during CD4+ T-cell activation. We showed that the expression level of miR-568 decreased during the activation of T cells, including Jurkat cells and human peripheral blood CD4+ T cells. When Jurkat or human peripheral blood CD4+ T cells were transfected with miR-568 mimics, cell activation was significantly inhibited, as shown by the inhibited expression of activation markers such as CD25, CD69 and CD154; decreased IL-2 production; and inhibited cell proliferation. Using software predictions and confirmatory experiments, we demonstrated that nuclear factor of activated T cells 5 (NFAT5) is a target of miR-568. Treg cells are an important CD4+ T-cell subpopulation, so we also evaluated the function of miR-568 in Treg-cell activation and differentiation. We showed that the miR-568 level decreased, while the NFAT5 protein level increased during CD4+CD25+ Treg-cell activation, and the transfection of miR-568 mimics inhibited the NFAT5 expression, inhibited the production of both TGF-β and IL-10 and also inhibited the proliferation of Treg cells. Our further study showed that over-expression of miR-568 can inhibit Treg-cell differentiation and can inhibit the suppressive effect of these cells on effector cells. In addition, inhibition of NFAT5 by siRNA-mediated knockdown can inhibit the activation and differentiation of Treg cells. These findings reveal that miR-568 can inhibit the activation and function of both CD4+ T cells and Treg cells by targeting NFAT5. Since miR-568 plays an important role in both CD4+ T cells and Treg cells, these findings may provide leads for the development of novel treatments for human inflammatory and autoimmune diseases.
Nucleolar proteins Bfr2 and Enp2 interact with DEAD-box RNA helicase Dbp4 in two different complexes
Authors: Soltanieh Sahar , Lapensée Martin , Dragon François 
Published: December 2013

AbstractDifferent pre-ribosomal complexes are formed during ribosome biogenesis, and the composition of these complexes is highly dynamic. Dbp4, a conserved DEAD-box RNA helicase implicated in ribosome biogenesis, interacts with nucleolar proteins Bfr2 and Enp2. We show that, like Dbp4, Bfr2 and Enp2 are required for the early processing steps leading to the production of 18S ribosomal RNA. We also found that Bfr2 and Enp2 associate with the U3 small nucleolar RNA (snoRNA), the U3-specific protein Mpp10 and various pre-18S ribosomal RNA species. Thus, we propose that Bfr2, Dbp4 and Enp2 are components of the small subunit (SSU) processome, a large complex of ∼80S. Sucrose gradient sedimentation analyses indicated that Dbp4, Bfr2 and Enp2 sediment in a peak of ∼50S and in a peak of ∼80S. Bfr2, Dbp4 and Enp2 associate together in the 50S complex, which does not include the U3 snoRNA; however, they associate with U3 snoRNA in the 80S complex (SSU processome). Immunoprecipitation experiments revealed that U14 snoRNA associates with Dbp4 in the 50S complex, but not with Bfr2 or Enp2. The assembly factor Tsr1 is not part of the ‘50S’ complex, indicating this complex is not a pre-40S ribosome. A combination of experiments leads us to propose that Bfr2, Enp2 and Dbp4 are recruited at late steps during assembly of the SSU processome.