bluuebunny/crossref_metadata_2025 huggingface dataset:
Precise dipolar coupling constant distribution analysis in proton multiple-quantum NMR of elastomers
Authors: Chassé Walter , Valentín Juan López , Genesky Geoffrey D. , Cohen Claude , Saalwächter Kay
Published: January 2011

In this work we present an improved approach for the analysis of 1H double-quantum nuclear magnetic resonance build-up data, mainly for the determination of residual dipolar coupling constants and distributions thereof in polymer gels and elastomers, yielding information on crosslink density and potential spatial inhomogeneities. We introduce a new generic build-up function, for use as component fitting function in linear superpositions, or as kernel function in fast Tikhonov regularization (ftikreg). As opposed to the previously used inverted Gaussian build-up function based on a second-moment approximation, this method yields faithful coupling constant distributions, as limitations on the fitting limit are now lifted. A robust method for the proper estimation of the error parameter used for the regularization is established, and the approach is demonstrated for different inhomogeneous elastomers with coupling constant distributions.
Electrokinetic motion of a charged colloidal sphere in a spherical cavity with magnetic fields
Authors: Hsieh Tzu H. , Keh Huan J.
Published: January 2011

The magnetohydrodynamic (MHD) effects on the translation and rotation of a charged colloidal sphere situated at the center of a spherical cavity filled with an arbitrary electrolyte solution when a constant magnetic field is imposed are analyzed at the quasisteady state. The electric double layers adjacent to the solid surfaces may have an arbitrary thickness relative to the particle and cavity radii. Through the use of a perturbation method to the leading order, the Stokes equations modified with the electric/Lorentz force term are dealt by using a generalized reciprocal theorem. Using the equilibrium double-layer potential distribution in the fluid phase from solving the linearized Poisson–Boltzmann equation, we obtain explicit formulas for the translational and angular velocities of the colloidal sphere produced by the MHD effects valid for all values of the particle-to-cavity size ratio. For the limiting case of an infinitely large cavity with an uncharged wall, our result reduces to the relevant solution for an unbounded spherical particle available in the literature. The boundary effect on the MHD motion of the spherical particle is a qualitatively and quantitatively sensible function of the parameters a/b and κa, where a and b are the radii of the particle and cavity, respectively, and κ is the reciprocal of the Debye screening length. In general, the proximity of the cavity wall reduces the MHD migration but intensifies the MHD rotation of the particle.
Surface tension of water–alcohol mixtures from Monte Carlo simulations
Authors: Biscay F. , Ghoufi A. , Malfreyt P.
Published: January 2011

Monte Carlo simulations are reported to predict the dependence of the surface tension of water–alcohol mixtures on the alcohol concentration. Alcohols are modeled using the anisotropic united atom model recently extended to alcohol molecules. The molecular simulations show a good agreement between the experimental and calculated surface tensions for the water–methanol and water–propanol mixtures. This good agreement with experiments is also established through the comparison of the excess surface tensions. A molecular description of the mixture in terms of density profiles and hydrogen bond profiles is used to interpret the decrease of the surface tension with the alcohol concentration and alcohol chain length.
Observation of anisotropically reflected colors in chiral monomer-doped cholesteric liquid crystals
Authors: Liu Cheng-Kai , Cheng Ko-Ting , Fuh Andy Ying-Guey
Published: January 2011

Observations of the anisotropically reflected colors from a film that is based on chiral monomer-doped cholesteric liquid crystals (CM-CLCs) are made. The key to obtaining such anisotropically reflected colors is the produced multidomain planar-CLCs structures, which can simultaneously reflect and scatter the incident light. UV polymerization of the CMs from one side of the cell results in an inhomogeneous distribution of pitch lengths across the cell, which is responsible for the anisotropically reflected colors from the two surfaces of the sample. Furthermore, the reflectivity and the bandwidth of the reflection spectrum depend on the cell gap.
Super-fermion representation of quantum kinetic equations for the electron transport problem
Authors: Dzhioev Alan A. , Kosov D. S.
Published: January 2011

We discuss the use of super-fermion formalism to represent and solve quantum kinetic equations for the electron transport problem. Starting with the Lindblad master equation for the molecule connected to two metal electrodes, we convert the problem of finding the nonequilibrium steady state to the many-body problem with non-Hermitian Liouvillian in super-Fock space. We transform the Liouvillian to the normal ordered form, introduce nonequilibrium quasiparticles by a set of canonical nonunitary transformations and develop general many-body theory for the electron transport through the interacting region. The approach is applied to the electron transport through a single level. We consider a minimal basis hydrogen atom attached to two metal leads in Coulomb blockade regime (out of equilibrium Anderson model) within the nonequilibrium Hartree–Fock approximation as an example of the system with electron interaction. Our approach agrees with exact results given by the Landauer theory for the considered models.
Magnetization reversal in exchange biased IrMn/Fe ring arrays
Authors: Hou Yu-feng , Zhan Qing-feng , Krishnan Kannan M.
Published: January 2011

We investigated the effect of exchange bias on the magnetization reversal behavior in ring-shaped IrMn/Fe lithographic structures. The magnetic anisotropy geometry of the exchange biased ring is revealed by fitting for the angular dependence of the exchange bias, Heb, and coercivity, Hc. Magnetic force microscopy images obtained at different field values along the hysteresis loop show that along the bias direction, the ring exhibits a magnetic reversal via nonuniform domain nucleation while perpendicular to the bias direction, the magnetic reversal occurs via coherent rotation. The difference in magnetic switching modes for these two field orientations is confirmed by micromagnetic simulations and interpreted by the effective field model.
Enhanced critical current properties in Ba0.6K0.4+xFe2As2 superconductor by overdoping of potassium
Authors: Wang Chunlei , Wang Lei , Gao Zhaoshun , Yao Chao , Wang Dongliang , Qi Yanpeng , Zhang Xianping , Ma Yanwei
Published: January 2011

Phase-pure polycrystalline Ba0.6K0.4+xFe2As2 with 0≤x≤0.1 were prepared using a one-step solid-state reaction method. We found that overdoping of potassium can improve the critical current density (Jc). High-field Jc for samples with x=0.1 is three times higher than that for samples with x=0. Overdoping of K has minimal effect on the critical transition temperature (Tc). Less than 0.5 K degradations in Tc was measured for samples with x=0.1. Transmission electron microscopy (TEM) revealed high concentration of dislocations in samples with x=0.1, resulting in enhanced flux pining. Further analyses on magnetization loops for powder samples confirm that K overdoping can promote intragrain Jc. Our results indicate that slight excess of K in Ba0.6K0.4Fe2As2 superconductor is beneficial to high-field applications.
On the role of frustration in the energy landscapes of allosteric proteins
Authors: Ferreiro Diego U. , Hegler Joseph A. , Komives Elizabeth A. , Wolynes Peter G.
Published: January 2011

Natural protein domains must be sufficiently stable to fold but often need to be locally unstable to function. Overall, strong energetic conflicts are minimized in native states satisfying the principle of minimal frustration. Local violations of this principle open up possibilities to form the complex multifunnel energy landscapes needed for large-scale conformational changes. We survey the local frustration patterns of allosteric domains and show that the regions that reconfigure are often enriched in patches of highly frustrated interactions, consistent both with the idea that these locally frustrated regions may act as specific hinges or that proteins may “crack” in these locations. On the other hand, the symmetry of multimeric protein assemblies allows near degeneracy by reconfiguring while maintaining minimally frustrated interactions. We also anecdotally examine some specific examples of complex conformational changes and speculate on the role of frustration in the kinetics of allosteric change.
Frequency dependent magnetization of superconductor strip
Authors: Thakur Kailash Prasad , Raj Ashish , Brandt Ernst Helmut , Sastry Pamidi V P S S
Published: January 2011

The frequency dependence of magnetic ac loss of thin superconductor strip subjected to
an ac magnetic field perpendicular to the surface of the strip is investigated by
incorporating a flux creep model into the critical state model of Brandt and Indenbom.
It is found that the reduced ac loss exhibits a maximum value at a frequency
f
m, which is a rapidly varying function of the applied ac magnetic field. At low magnetic field,
f
m
becomes zero, and ac loss decreases with frequency as a power law (∼f
− 2/n
). Whereas at high
magnetic field f
m
becomes infinite and ac loss increases with frequency, still following the power law (∼f
1/n
). The analytical results are substantiated with experimental data and the results of a 2D
finite element simulation.
Three-dimensional electrokinetic tweezing: device design, modeling, and control algorithms
Authors: Probst Roland , Shapiro Benjamin
Published: January 2011

We show how to extend electrokinetic tweezing (which can manipulate any visible particles and has more favorable force scaling than optical actuation enabling manipulation of nanoscale objects to nanoscopic precision) from two-dimensional control to the third dimension (3D). A novel and practical multi-layer device is presented that can create both planar and vertical flow and electric field modes. Feedback control algorithms are developed and demonstrated in realistic simulations to show 3D manipulation of one and two particles independently. The design and control results presented here are the essential next step to go from current 2D manipulation capabilities to an experimental demonstration of nano-precise 3D electrokinetic tweezing in a microfluidic system. Doing so requires integration with vision-based nano-precise 3D particle imaging, a capability that has been shown in the literature and which we are now combining with the 3D actuation and control methods demonstrated here.
Good quotients of Mori dream spaces
Authors: Bäker Hendrik
Published: January 2011

We show that good quotients of algebraic varieties with finitely generated Cox ring have again finitely generated Cox ring.
Stability of syzygy bundles
Authors: Macias Marques Pedro , Miró-Roig Rosa
Published: January 2011

We show that given integers 

N
N

,

d
d

and 

n
n

such that

N
≥
2

,
(
N
,
d
,
n
)

{N\ge 2}, (N,d,n)

≠
(
2
,
2
,
5
)

\ne (2,2,5)

, and

N
+
1
≤
n
≤

(

d
+
N

N

)

{N+1\le n\le \tbinom {d+N}{N}}

, there is a family of 

n
n

monomials in

K

[

X
0

,
…
,

X
N

]

K\left [X_0,\ldots ,X_N\right ]

of degree 

d
d

such that their syzygy bundle is stable. Case

N
≥
3

{N\ge 3}

was obtained independently by Coandǎ with a different choice of families of monomials.

For

(
N
,
d
,
n
)
=
(
2
,
2
,
5
)

{(N,d,n)=(2,2,5)}

, there are 

5
5

monomials of degree 

2
2

in

K

[

X
0

,

X
1

,

X
2

]

K\left [X_0,X_1,X_2\right ]

such that their syzygy bundle is semistable.
Existence of solutions with asymptotic behavior of exterior problems of Hessian equations
Authors: Dai Limei
Published: January 2011

In this paper, we use the Perron method to prove the existence of viscosity solutions with asymptotic behavior at infinity to Hessian equations.
Restriction of hypergeometric 𝒟-modules with respect to coordinate subspaces
Authors: Fernández-Fernández María-Cruz , Walther Uli
Published: January 2011

We compute the restriction of an

A
A

-hypergeometric

D

\mathscr {D}

-module with respect to a coordinate subspace under certain genericity conditions on the parameter.
Subsidies and Crowding Out: A Double‐Hurdle Model of Fertilizer Demand in Malawi
Authors: Ricker-Gilbert Jacob , Jayne Thomas S. , Chirwa Ephraim
Published: January 2011

This article uses a double‐hurdle model with panel data from Malawi to investigate how fertilizer subsidies affect farmer demand for commercial fertilizer. The article controls for potential endogeneity caused by the nonrandom targeting of fertilizer subsidy recipients. Results show that on average 1 additional kilogram of subsidized fertilizer crowds out 0.22 kg of commercial fertilizer, but crowding out ranges from 0.18 among the poorest farmers to 0.30 among relatively nonpoor farmers. This indicates that targeting fertilizer subsidies to the rural poor is likely to maximize the contribution of the subsidy program to total fertilizer use.
The role of the antimicrobial compound 2,4-diacetylphloroglucinol in the impact of biocontrol Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators
Authors: Couillerot Olivier , Combes-Meynet Emeline , Pothier Joël F. , Bellvert Floriant , Challita Elita , Poirier Marie-Andrée , Rohr René , Comte Gilles , Moënne-Loccoz Yvan , Prigent-Combaret Claire
Published: January 2011

Pseudomonads producing the antimicrobial metabolite 2,4-diacetylphloroglucinol (Phl) can control soil-borne phytopathogens, but their impact on other plant-beneficial bacteria remains poorly documented. Here, the effects of synthetic Phl and Phl+Pseudomonas fluorescensF113 onAzospirillum brasilensephytostimulators were investigated. MostA. brasilensestrains were moderately sensitive to Phl.In vitro, Phl induced accumulation of carotenoids and poly-β-hydroxybutyrate-like granules, cytoplasmic membrane damage and growth inhibition inA. brasilenseCd. Experiments withP. fluorescensF113 and a Phl−mutant indicated that Phl production ability contributed toin vitrogrowth inhibition ofA. brasilenseCd and Sp245. Under gnotobiotic conditions, each of the three strains,P. fluorescensF113 andA. brasilenseCd and Sp245, stimulated wheat growth. Co-inoculation ofA. brasilenseSp245 andPseudomonasresulted in the same level of phytostimulation as in single inoculations, whereas it abolished phytostimulation whenA. brasilenseCd was used.PseudomonasPhl production ability resulted in lowerAzospirillumcell numbers per root system (based on colony counts) and restricted microscale root colonization of neighbouringAzospirillumcells (based on confocal microscopy), regardless of theA. brasilensestrain used. Therefore, this work establishes that Phl+pseudomonads have the potential to interfere withA. brasilensephytostimulators on roots and with their plant growth promotion capacity.
Role of FlbT in flagellin production in Brucella melitensis
Authors: Ferooz Jonathan , Lemaire Julien , Letesson Jean-Jacques
Published: January 2011

It was recently demonstrated that the pathogenBrucella melitensisproduces a polar sheathed flagellum under the control of the master regulator FtcR. However, the regulatory mechanism controlling the flagellar assembly remains unknown. In this work, we investigate the flagellar hierarchy ofB. melitensisas well as the flagellin FliC regulation. We show that a mutation infliForflgE(coding for the basal body structure and the hook, respectively) does not affect FliC synthesis, suggesting that production of FliC does not depend on the flagellar assembly. We demonstrate that FlbT is a FliC activator since inactivation offlbTcauses a decrease infliCexpression by using afliC–lacZtranslational reporter construct. Moreover, the quantitative real-time PCR and Western blot analysis show a marked decrease infliCmRNA and FliC protein level, respectively. Conversely, theB. melitensiswild-type strain overexpressingflaFfails to produce FliC, suggesting an opposite function. Interestingly, the expression of theflbTgene in anftcRor anflbTmutant restores FliC production, demonstrating that FlbT plays a regulatory checkpoint role in FliC synthesis. This mechanism could be conserved in theRhizobialessince complementation of anflbTor anftcRmutant withflbTfromSinorhizobium melilotirestores FliC synthesis.
RpoE1, an extracytoplasmic function sigma factor, is a repressor of the flagellar system in Brucella melitensis
Authors: Ferooz Jonathan , Lemaire Julien , Delory Marie , De Bolle Xavier , Letesson Jean-Jacques
Published: January 2011

The genome of Brucella melitensis contains genes coding for the sigma factors RpoD, RpoN, RpoH1, RpoH2, RpoE1 and RpoE2. Previously published data show that B. melitensis is flagellated and that an rpoE1 mutant overexpresses the flagellar protein FlgE. In this study, we demonstrate that mutation of rpoE1 causes an overexpression of the flagellar genes fliF, flgE, fliC, flaF and flbT, correlating with the production of a longer filament and thereby demonstrating that RpoE1 acts as a flagellar repressor. Moreover, mutation of rpoE1 increases the promoter activity of the flagellar master regulator ftcR, suggesting that RpoE1 acts upstream of ftcR. Together, these data show that RpoE1 represses the flagellar synthesis and filament length in B. melitensis.
Emw1p/YNL313cp is essential for maintenance of the cell wall in Saccharomyces cerevisiae
Authors: Sipling Tatjana , Zhai Chao , Panaretou Barry
Published: January 2011

There are six essential genes in the Saccharomyces cerevisiae genome which encode proteins bearing the tetratricopeptide repeat (TPR) domain that mediates protein–protein interaction. Thus far, the function of one of them, YNL313c, remains unknown. Our conditional mutants of YNL313c display osmoremedial temperature sensitivity, hypersensitivity to both Calcofluor White and low concentrations of SDS, and osmoremedial caffeine sensitivity. These are hallmarks of mutants that display cell wall defects. Accordingly we rename the gene as EMW1 (essential for maintenance of the cell wall). Loss of Emw1p function is not associated with abrogation of the cell wall integrity (CWI) MAP kinase cascade. Instead, emw1ts
mutants activate this cascade even at permissive temperature, indicating that loss of Emw1p function does not cause a defect in sensors and effectors of cell wall signalling, but leads to a cell wall defect directly. Constitutive activation of the CWI cascade is reflected by the overproduction of chitin by emw1ts
mutants, a compensatory response frequently displayed by cell wall mutants. Growth is restored to emw1ts
mutants incubated at otherwise non-permissive temperature when GFA1 is overexpressed. GFA1 encodes the hexosephosphate aminotransferase that catalyses the rate-limiting step in the pathway that synthesizes the chitin precursor UDP-GlcNAc. The possibility that Emw1p is required for function of Gfa1p was ruled out, because the emw1ts
phenotype persists when the requirement for Gfa1p is bypassed. Furthermore, if loss of Emw1p function leads to loss of function of Gfa1p, then chitin synthesis would be diminished. Instead, a stimulation of the synthesis of this polymer is detected. Consequently, the defect associated with emw1ts
mutants may be associated with compromise in one of the remaining processes that depend on UDP-GlcNAc, namely N-glycosylation or glycosylphosphatidylinositol (GPI)-anchor synthesis.
Plastid Stromule Branching Coincides with Contiguous Endoplasmic Reticulum Dynamics
Authors: Schattat Martin , Barton Kiah , Baudisch Bianca , Klösgen Ralf Bernd , Mathur Jaideep
Published: January 2011

Stromules are stroma-filled tubules extending from plastids whose rapid extension toward or retraction from other plastids has suggested a role in interplastidic communication and exchange of metabolites. Several studies point to sporadic dilations, kinks, and branches occurring along stromule length but have not elucidated the underlying basis for these occurrences. Similarly, although specific details on interacting partners have been missing, a consensus viewpoint suggests that stromules increase the interactive surface of a plastid with its cytoplasmic surroundings. Here, using live imaging, we show that the behavior of dynamic, pleomorphic stromules strongly coincides with that of cortical endoplasmic reticulum (ER) tubules. Covisualization of fluorescent protein-highlighted stromules and the ER in diverse cell types clearly suggests correlative dynamics of the two membrane-bound compartments. The extension and retraction, as well as directional changes in stromule branches occur in tandem with the behavior of neighboring ER tubules. Three-dimensional and four-dimensional volume rendering reveals that stromules that extend into cortical regions occupy channels between ER tubules possibly through multiple membrane contact sites. Our observations clearly depict coincidental stromule-ER behavior and suggest that either the neighboring ER tubules shape stromules directly or the behavior of both ER and stromules is simultaneously dictated by a shared cytoskeleton-based mechanism. These new observations strongly implicate the ER membrane in interactions with stromules and suggest that their interacting surfaces might serve as major conduits for bidirectional exchange of ions, lipids, and metabolites between the two organelles.
Bmi1 regulates cell fate via tumor suppressor WWOX repression in small‐cell lung cancer cells
Authors: Kimura Masaki , Takenobu Hisanori , Akita Nobuhiro , Nakazawa Atsuko , Ochiai Hidemasa , Shimozato Osamu , Fujimura Yu‐ichi , Koseki Haruhiko , Yoshino Ichiro , Kimura Hideki , Nakagawara Akira , Kamijo Takehiko
Published: January 2011

Mortality from lung cancer is important worldwide. Recently, epigenetic aberration of lung cancer, not only genomic DNA methylation but also chromatin modification, has become an important target for lung cancer research, although previous research has demonstrated that lung cancer develops as a result of both environmental and genetic factors. Here, we demonstrated that an epigenetic regulator/polycomb group protein Bmi1 is more highly expressed in small‐cell lung cancer (SCLC) than in non‐small‐cell lung cancer by immunohistochemical analysis. In vitro experiments indicated that Bmi1 reduction by lentivirus‐derived shRNA significantly suppressed proliferation, colony formation and in vivo tumor formation. Importantly, apoptosis was induced by Bmi1 depletion in small‐cell lung cancer cells. Furthermore, a tumor suppressor WWOX was identified as a Bmi1 target in the cells by a chromatin immunoprecipitation assay and a quantitative real‐time PCR assay; WWOX had a role as a tumor suppressor in SCLC cells; therefore, the Bmi1/WWOX pathway could be a new candidate for a new therapeutic approach for SCLC. (Cancer Sci 2011; 102: 983–990)
Downregulation of a newly identified laminin, laminin‐3B11, in vascular basement membranes of invasive human breast cancers
Authors: Mori Taizo , Kariya Yoshinobu , Komiya Eriko , Higashi Shouichi , Miyagi Yohei , Sekiguchi Kiyotoshi , Miyazaki Kaoru
Published: January 2011

Laminins present in the basement membranes (BM) of blood vessels are involved in angiogenesis and other vascular functions that are critical for tumor growth and metastasis. Two major vascular laminins, the α4 (laminin‐411/421) and α5 (laminin‐511/521) types, have been well characterized. We recently found a third type of vascular laminin, laminin‐3B11, consisting of the α3B, β1 and γ1 chains, and revealed its biological activity. Laminin‐3B11 potently stimulates vascular endothelial cells to extend lamellipodial protrusions. To understand the roles of laminin‐3B11 in blood vessel functions and tumor growth, we examined localization of the laminin α3B chain in normal mammary glands and breast cancers, in comparison with the α4 and α5 laminins. In the immunohistochemical analysis, the α3B laminin was co‐localized with the α4 and α5 laminins in the BM of venules and capillaries of normal breast tissues, but α3B was scarcely detected in vessels near invasive breast carcinoma cells. In contrast, the α4 laminin was overexpressed in capillaries of invasive carcinomas, where a large number of macrophages were found. The α5 laminin appeared to be weakly downregulated in cancer tissues, especially in capillary vessels. Furthermore, our in vitro analysis indicated that TNF‐α significantly suppressed the laminin α3B expression in vascular endothelial cells, while it, as well as IL‐1β and TGF‐α, upregulated the α4 expression. These results suggest that Lm3B11/3B21 may be required for normal mature vessels and interfere with tumor angiogenesis. (Cancer Sci 2011; 102: 1095–1100)
Resveratrol as an adjunct therapy in cyclophosphamide‐treated MCF‐7 cells and breast tumor explants
Authors: Singh Neetu , Nigam Manisha , Ranjan Vishal , Zaidi Deeba , Garg Vivek Kumar , Sharma Sharad , Chaturvedi Rashmi , Shankar Rishi , Kumar Sadan , Sharma Ramesh , Mitra Kalyan , Balapure Anil K. , Rath Srikanta K.
Published: January 2011

Cyclophosphamide (CPA) has efficacy as a breast cancer therapy. However, toxicity to CPA limits its clinical applications. Hence there is a need to develop compounds that may be combined with it to improve the efficacy and overcome toxicity. We showed previously that Resveratrol (RES), a chemopreventive agent, increased the growth inhibitory effect of CPA‐treated MCF‐7 cells. Here we have explored the molecular basis of 5 mM CPA and 50 μM RES as a combination on cell‐cycle progression, apoptosis and oxidative stress in MCF‐7 breast cancer cells. Efficacy of the combination was also evaluated in a serum‐free tumor explant culture model. The combination elicited enhanced anti‐proliferative action coupled with differential expression of cell‐cycle, apoptosis and stress factors. Furthermore, co‐treatment superiority in histologically validated ER positive breast cancer explants suggests that this combination may be a worthy future clinical anti‐neoplastic regimen. (Cancer Sci 2011; 102: 1059–1067)
The response of subcutaneous connective tissue to newly developed calcium phosphate‐based root canal sealers
Authors: Khashaba R. M. , Moussa M. M. , Chutkan N. B. , Borke J. L.
Published: January 2011

Khashaba RM, Moussa MM, Chutkan NB, Borke JL. The response of subcutaneous connective tissue to newly developed calcium phosphate‐based root canal sealers. International Endodontic Journal.

Aim  To evaluate the histopathologic biocompatibility of two new calcium phosphate‐based sealers (CPS‐1 & CPS‐2) with a commercially available calcium hydroxide‐based sealer (Acroseal).

Methodology  Polyethylene tubes were filled with freshly mixed sealers and implanted subcutaneously in the dorsal connective tissue of rats. Empty tubes were used as controls. Histopathological examinations were conducted at 7, 15, 30, 60 and 90 days after the implantation procedure. The presence of inflammation and predominant cell types were analysed statistically with Mann–Whitney U and Kruskal–Wallis non‐parametric tests. Fibrous connective tissue thickness adjacent to each sample was recorded. Differences were tested for significance using anova and ‘Duncan’s’ multiple comparison test (P < 0.05).

Results  CPS‐1 sealer was associated with severe inflammation and remained an irritation throughout the 90‐day implantation period; the tissue reaction pattern was stromal fibrosis. The control, CPS‐2 and Acroseal sealers had similar patterns of irritation, which were more severe initially and diminished with time creating a thin fibrous capsule around the implant with a complete absence of inflammatory cells. There was no difference in tissue reaction between the control, CPS‐1, CPS‐2 and Acroseal groups amongst the first two observation periods (P > 0.05). However, there was a highly significant difference between the same groups at the last two observation periods (P < 0.01). Also, there were highly significant differences between the observation periods within all four groups at 7, 15, 30, 60 and 90 days (P < 0.01).

Conclusion  CPS‐1 sealer was not biocompatible. CPS‐2 sealer and Acroseal had a favourable biocompatibility level based on the histological findings.
Rad52 function prevents chromosome loss and truncation in Candida albicans
Authors: Andaluz E. , Bellido A. , Gómez‐Raja J. , Selmecki A. , Bouchonville K. , Calderone R. , Berman J. , Larriba G.
Published: January 2011

RAD52 is required for almost all recombination events in Saccharomyces cerevisiae. We took advantage of the heterozygosity of HIS4 in the Candida albicans SC5314 lineage to study the role of Rad52 in the genomic stability of this important fungal pathogen. The rate of loss of heterozygosity (LOH) at HIS4 in rad52‐ΔΔ strains was ∼10−3, at least 100‐fold higher than in Rad52+ strains. LOH of whole chromosome 4 or truncation of the homologue that carries the functional HIS4 allele was detected in all 80 rad52‐ΔΔ His auxotrophs (GLH –GL lab His‐) obtained from six independent experiments. Isolates that had undergone whole chromosome LOH, presumably due to loss of chromosome, carried two copies of the remaining homologue. Isolates with truncations carried centric fragments of broken chromosomes healed by de novo telomere addition. GLH strains exhibited variable degrees of LOH across the genome, including two strains that became homozygous for all the heterozygous markers tested. In addition, GLH strains exhibited increased chromosomal instability (CIN), which was abolished by reintroduction of RAD52. CIN of GLH isolates is reminiscent of genomic alterations leading to cancer in human cells, and support the mutator hypothesis in which a mutator mutation or CIN phenotype facilitate more mutations/aneuploidies.
A MADS‐box transcription factor MoMcm1 is required for male fertility, microconidium production and virulence in Magnaporthe oryzae
Authors: Zhou Xiaoying , Liu Wende , Wang Chenfang , Xu Qijun , Wang Yang , Ding Shengli , Xu Jin‐Rong
Published: January 2011

Appressorium formation is a key step in the infection cycle of Magnaporthe oryzae. Mst12 is a transcription factor essential for appressorium penetration and invasive growth. In this study we used the affinity purification approach to identify proteins that physically associate with Mst12. One of the Mst12‐interacting genes identified was MoMCM1, which encodes a MADS‐box protein orthologous to yeast Mcm1. MoMcm1 interacted with both Mst12 and Mata‐1 in yeast two‐hybrid assays. Deletion of MoMCM1 resulted in the loss of male fertility and microconidium production. The Momcm1 mutant was defective in appressorium penetration and formed narrower invasive hyphae, which may be responsible for its reduced virulence. In transformants expressing MoMCM1–eGFP fusion, GFP signals were observed in the nucleus. We also generated the Momcm1 mst12 double mutant, which was defective in penetration and non‐pathogenic. On hydrophilic surfaces, germ tubes produced by the double mutant were severely curved, and 20% of them formed appressoria. In contrast, the Momcm1 or mst12 mutant did not form appressoria on hydrophilic surfaces. These results suggest that MoMCM1 and MST12 have overlapping functions to suppress appressorium formation under non‐conducive conditions. MoMcm1 may interact with Mst12 and MatA‐1 to regulate germ tube identity and male fertility respectively.
DNA supercoiling is differentially regulated by environmental factors and FIS in Escherichia coli and Salmonella enterica
Authors: Cameron Andrew D. S. , Stoebel Daniel M. , Dorman Charles J.
Published: January 2011

Although Escherichia coli and Salmonella enterica inhabit similar niches and employ similar genetic regulatory programmes, we find that they differ significantly in their DNA supercoiling responses to environmental and antibiotic challenges. Whereas E. coli demonstrates large dynamic transitions in supercoiling in response to growth phase, osmotic pressure and novobiocin treatment, supercoiling levels are much less variable in S. enterica. The FIS protein is a global regulator of supercoiling in E. coli, but it was found to have less influence over supercoiling control in S. enterica. These inter‐species differences fine‐tune gene promoters to endogenous supercoiling and FIS levels. Transferring a Salmonella virulence gene promoter (PssrA) into a new enteric host (E. coli) caused aberrant expression in response to stimulatory signals. Reciprocal horizontal transfer of topA promoters, which control expression of topoisomerase I, between E. coli and S. enterica revealed how these orthologous promoters have evolved to respond differentially to FIS and supercoiling levels in their cognate species. This also identified a previously unrecognized osmoregulation of topA expression that is independent of FIS and supercoiling in both E. coli and S. enterica. These findings suggest that E. coli and S. enterica may be unexpectedly divergent in their global regulation of cellular physiology.
Complexation of Hg with phytochelatins is important for plant Hg tolerance
Authors: CARRASCO‐GIL SANDRA , ÁLVAREZ‐FERNÁNDEZ ANA , SOBRINO‐PLATA JUAN , MILLÁN ROCÍO , CARPENA‐RUIZ RAMÓN O. , LEDUC DANIKA L. , ANDREWS JOY C. , ABADÍA JAVIER , HERNÁNDEZ LUÍS E.
Published: January 2011

Three‐week‐old alfalfa (Medicago sativa), barley (Hordeum vulgare) and maize (Zea mays) were exposed for 7 d to 30 µm of mercury (HgCl2) to characterize the Hg speciation in root, with no symptoms of being poisoned. The largest pool (99%) was associated with the particulate fraction, whereas the soluble fraction (SF) accounted for a minor proportion (<1%). Liquid chromatography coupled with electro‐spray/time of flight mass spectrometry showed that Hg was bound to an array of phytochelatins (PCs) in root SF, which was particularly varied in alfalfa (eight ligands and five stoichiometries), a species that also accumulated homophytochelatins. Spatial localization of Hg in alfalfa roots by microprobe synchrotron X‐ray fluorescence spectroscopy showed that most of the Hg co‐localized with sulphur in the vascular cylinder. Extended X‐ray Absorption Fine Structure (EXAFS) fingerprint fitting revealed that Hg was bound in vivo to organic‐S compounds, i.e. biomolecules containing cysteine. Albeit a minor proportion of total Hg, Hg–PCs complexes in the SF might be important for tolerance to Hg, as was found with Arabidopsis thaliana mutants cad2‐1 (with low glutathione content) and cad1‐3 (unable to synthesize PCs) in comparison with wild type plants. Interestingly, high‐performance liquid chromatography‐electrospray ionization‐time of flight analysis showed that none of these mutants accumulated Hg–biothiol complexes.
Informed consent and patient understanding of blood transfusion
Authors: Court E. L. , Robinson J. A. , Hocken D. B.
Published: January 2011

Background: Obtaining separate informed consent for blood transfusion is mandatory in some countries. Although patients should be informed about risks and benefits of transfusion, studies suggest this does not happen routinely in the UK and the patient perspective is lacking in the current literature.

Aim: To explore provision of information and the consent process for patients receiving blood transfusions at our hospital.

Objectives: To assess patient recall of the consent process, information conveyed, ease in understanding discussions and perceived knowledge of transfusion afterwards.

Methods: All 342 adult patients for whom blood was cross‐matched between 1 March 2008 and 30 April 2008 were sent postal questionnaires.

Results: One hundred and sixty‐four questionnaires were returned. Overall, 59·1% of patients said someone explained they might need a transfusion; of those 86·7% felt the reason had been explained. Only 58·8% of patients felt informed of what transfusion involves, with 67·0% told of the benefits and 27·8% informed of risks. Overall, 51·5% of patients said this information was easy to understand, but only 26·8% were aware of a transfusion information leaflet. Of those receiving leaflets, all said they read it and had no questions. Despite this, 61·9% were satisfied overall with the information received.

Conclusion: Information leaflets could increase the information available to patients, with minimal impact on health care professionals' time. Leaflets are available, free of charge, from the National Health Service Blood and Transplant website. These have been introduced at each bedside, in pre‐op packs and in outpatient clinics, with re‐assessment planned in 6 months.
Preemptive deceased donor kidney transplant not associated with patient survival benefit in minority kidney transplant recipients
Authors: Keith Douglas Scott
Published: January 2011

Keith DS. Preemptive deceased donor kidney transplant not associated with patient survival benefit in minority kidney transplant recipients.  Clin Transplant 2012: 26: 82–86.  © 2011 John Wiley & Sons A/S.

Abstract:  Previous studies have shown an inverse association between pre‐transplant dialysis exposure and post‐kidney transplant outcomes. Socioeconomic and allocation factors, in contrast to medical factors, play a greater role in dialysis exposure among minorities, and medical causes for delay may impact post‐transplant outcomes. This study sought to test whether minorities behaved similarly to Caucasians with regard to the effect of duration of dialysis on post‐transplant outcomes. All primary deceased donor kidney transplants between 1997 and 2004 (n = 54 162) were analyzed from the Organ Procurement and Transplant Network database and were categorized as either Caucasian or minority. Adjusted patient and graft survivals were determined in each subgroup based on the duration of pre‐transplant dialysis. Caucasians recipients show a clear stepwise increase in risk of graft failure and death with increasing duration of dialysis. The risk of graft failure among minorities increased less without a clear stepwise pattern. The risk of death, however, showed a U‐shaped risk profile with the highest risk of death among preemptive transplants and recipients with more than five yr of dialysis. The disparate effect of dialysis on minorities suggests that a selection bias and not a biologic effect may explain the association between dialysis duration and outcomes after kidney transplantation previously reported.
Risk of colorectal neoplasia in patients with solid organ transplantation
Authors: Park Ho Yong , Chang Byung Jin , Lim Seong Woo , Kim Jeong , Kim Jin Yong , Chang Dong Kyung , Son Hee Jung , Rhee Poong‐Lyul , Kim Jae J. , Rhee Jong Chul , Kim Young‐Ho
Published: January 2011

Park HY, Chang BJ, Lim SW, Kim J, Kim JY, Chang DK, Son HJ, Rhee P‐L, Kim JJ., Rhee JC, Kim Y‐H. Risk of colorectal neoplasia in patients with solid organ transplantation.  Clin Transplant 2012: 26: 50–56.  © 2011 John Wiley & Sons A/S.

Abstract:  The incidence of colorectal adenomas and advanced neoplasia in the transplant population has not been well characterized. The aim of this study was to determine whether or not there was an increased incidence of colorectal adenomas and advanced neoplasia in solid organ transplantation (SOT) recipients compared with an average‐risk population. We reviewed 360 patients with solid organ transplants who underwent colonoscopy between February 1995 and July 2008, and 360 age‐ and gender‐matched patients in an average‐risk population. The mean duration from transplantation to colonoscopy in the SOT group was 40.4 ± 34.0 months. Ninety‐three (25.8%) adenomas were detected in the SOT group, while 98 (27.2%) adenomas were detected in the control group (p = 0.763). There was a statistically significant difference (p < 0.0001) in the number of patients with advanced neoplasia in the SOT group (24 patients [6.7%]) compared with the control group (3 patients [0.8%]). The independent risk factors of advanced neoplasia were old age (odds ratio [OR], 1.067; 95% CI, 1.019–1.118) and transplantation (OR, 6.069; 95% CI, 1.455–25.314). In summary, there was a significant increase in the incidence of advanced colorectal neoplasia in SOT recipients. The reason for this finding is unclear, and studies with a larger number of patients are needed to further evaluate this group.
Plant U‐box armadillo repeat proteins AtPUB18 and AtPUB19 are involved in salt inhibition of germination in Arabidopsis
Authors: Bergler J. , Hoth S.
Published: January 2011

Plant U‐box armadillo repeat (PUB‐ARM) proteins represent a type of E3 ubiquitin ligase. PUB‐ARM proteins have various functions in plant development, plant defence and plant stress responses. The so far uncharacterised PUB‐ARM proteins AtPUB18 and AtPUB19 are highly homologous to each other and regulated on the transcript level by ABA and NaCl. To investigate their physiological function, we isolated and characterised two Arabidopsis mutants and named them pub18‐1 and pub19‐1. However, these single mutants did not show any ABA‐ or salt‐dependent phenotype. In contrast, pub18‐1/pub19‐1 double mutant seeds were less sensitive to ABA and NaCl inhibition of seed germination compared to wild‐type seeds, indicating that both PUB‐ARM proteins may coordinately function as regulatory components in ABA or salt inhibition of germination.
Enhanced transpiration rate in the high pigment 1 tomato mutant and its physiological significance
Authors: Carvalho R. F. , Aidar S. T. , Azevedo R. A. , Dodd I. C. , Peres L. E. P.
Published: January 2011

Tomato high pigment (hp) mutants represent an interesting horticultural resource due to their enhanced accumulation of carotenoids, flavonoids and vitamin C. Since hp mutants are known for their exaggerated light responses, the molecules accumulated are likely to be antioxidants, recruited to deal with light and others stresses. Further phenotypes displayed by hp mutations are reduced growth and an apparent disturbance in water loss. Here, we examined the impact of the hp1 mutation and its near isogenic line cv Micro‐Tom (MT) on stomatal conductance (gs), transpiration (E), CO2 assimilation (A) and water use efficiency (WUE). Detached hp1 leaves lost water more rapidly than control leaves, but this behaviour was reversed by exogenous abscisic acid (ABA), indicating the ability of hp1 to respond to this hormone. Although attached hp1 leaves had enhanced gs, E and A compared to control leaves, genotypic differences were lost when water was withheld. Both instantaneous leaf‐level WUE and long‐term whole plant WUE did not differ between hp1 and MT. Our results indicate a link between exaggerated light response and water loss in hp1, which has important implications for the use of this mutant in both basic and horticultural research.
Epiphytes and associated fauna on the brown alga Fucus vesiculosus in the Baltic and the North Seas in relation to different abiotic and biotic variables
Authors: Kersen Priit , Kotta Jonne , Bučas Martynas , Kolesova Natalja , Deķere Zane
Published: January 2011

Fucus vesiculosus L. is an important habitat‐forming macroalga both in the saline and high diverse North Sea and the diluted and low diversity Baltic Sea. Despite its importance, comparisons of the spatial patterns of its epiphytes have rarely been reported. In this study we examined the species composition and density of macro‐epiphytes and mobile fauna on the canopy‐forming macroalga F. vesiculosus inhabiting different regimes of wave exposure in the North and Baltic Seas. The North and Baltic Seas had distinct epiphyte and mobile faunal communities. Wave exposure and segments of host fronds significantly contributed to the variability in species composition and dominance structure of epiphytes on F. vesiculosus in the North Sea and Baltic Sea. The study indicated that there is no clear spatial scale where environmental variables best predicted epiphytic and mobile faunal communities, and the formation of epiphytic and faunal communities is an interplay of factors operating through micro‐ to regional scales.
Atypical development of Chaetomorpha antennina in culture (Cladophorales, Chlorophyta)
Authors: Leliaert Frederik , D'hondt Sofie , Tyberghein Lennert , Verbruggen Heroen , De Clerck Olivier
Published: January 2011

The green seaweed genus Chaetomorpha is characterized by unbranched filaments. Molecular phylogenetic data indicate that Chaetomorpha forms a clade that is nested in a paraphyletic assemblage of branched species (Cladophora). It follows that the unbranched condition is evolutionarily conserved and likely evolved early in the evolution of this clade. In this study we show that under laboratory culture conditions, the filaments of C. antennina frequently produce lateral branches, similar to Cladophora. Our results thus indicate that the unbranched thallus architecture is not entirely genetically constrained, but at least in part subject to morphological plasticity. Additionally, culture observations of C. antennina allowed a detailed study of rhizoidal development, which seems unique among Cladophorales.
Genetic diversity of the mangrove‐associated alga Bostrychia radicans/Bostrychia moritziana (Ceramiales, Rhodophyta) from southern Central America
Authors: Zuccarello Giuseppe C. , Buchanan Joe , West John A. , Pedroche Francisco F.
Published: January 2011

Previous studies suggested that the biodiversity of the mangrove‐associated Bostrychia radicans/Bostrychia moritziana species complex on the Pacific coast of Central America, based on genetic and reproductive data, were low compared with similar areas on the Atlantic coast. Evolutionary scenarios were proposed based on either a recent introduction to the Pacific, or a more uniform environment leading to genetically connected populations and low differentiation between populations. We sampled more extensively in southern Mexico, Guatemala and El Salvador and sequenced the samples for the RuBisCo spacer. Our results show that genetic diversity is high in these populations. Many haplotypes retrieved are also found in the Atlantic Ocean (USA, Brazil), an observation not made before. Data suggest that populations are highly differentiated with little evidence of isolation‐by‐distance. The population at La Puntilla, El Salvador is highly differentiated from other populations. Data also suggest that diversity is reduced in a northerly direction, with only one haplotype, unique to Pacific Central America, found north of Chiapas, Mexico. This could be due to northern expansion of this unique genotype as sea surface temperatures ameliorated following the last glacial maximum. Our data do not support the previous proposition of low diversity in the east central Pacific and suggest that much of the Pacific Central America diversity is from before the closure of the Isthmus of Panama.
Genome‐wide association studies for discovery of genes involved in asthma
Authors: AKHABIR LOUBNA , SANDFORD ANDREW J.
Published: January 2011

Asthma is the result of a complex interaction between environmental factors and genetic variants that confer susceptibility. Studies of the genetics of asthma have previously been conducted using linkage designs and candidate gene association studies. Recently, the association study design has been extended from specific candidate genes to an unbiased genome‐wide approach: the genome‐wide association study (GWAS). To date, there have been 12 GWAS to look for susceptibility loci for asthma and related traits. The first GWAS for asthma discovered a novel associated locus on chromosome 17q21 encompassing the genes ORMDL3, GSDMB and ZPBP2. None of these genes would have been selected in a candidate association study based on current knowledge of the functions of these genes. Nevertheless, this finding has been consistently replicated in independent populations of European ancestry and also in other ethnic groups. Thus, chromosome 17q21 seems to be a true asthma susceptibility locus. Other genes that were identified in more than one GWAS are IL33, RAD50, IL1RL1 and HLA‐DQB1. Additional novel susceptibility genes identified in a single study include DENND1BI and IL2RB. Discovering the causal mechanism behind these associations is likely to yield great insights into the development of asthma. It is likely that further meta‐analyses of asthma GWAS data from existing international consortia will uncover more novel susceptibility genes and further increase our understanding of this disease.