bluuebunny/crossref_metadata_2025 huggingface dataset:
Neutron diffraction studies for realtime leaching of catalytic Ni
Authors: Iles Gail N. , Devred François , Henry Paul F. , Reinhart Guillaume , Hansen Thomas C.
Published: July 2014

The leaching of Al from intermetallic samples of Nickel Aluminium alloys to form Raney-type nickel catalysts is widely used in the hydrogenation industry, however, little is known of the leaching process itself. In this study, the leaching of Al was measured in realtime, in situ, using the high-flux powder neutron diffractometer, D20, at the Institut Laue-Langevin. Despite the liberation of hydrogen and effervescent nature of the reaction the transformation of the dry powder phases into Raney-type Ni was determined. Samples produced by gas-atomisation were found to leach faster than those produced using the cast and crushed technique. Regardless of processing route of the precursor powder, the formation of spongy-Ni occurs almost immediately, while Ni2Al3 and NiAl3 continue to transform over longer periods of time. Small-angle scattering and broadening of the diffraction peaks is an evidence for the formation of the smaller Ni particles. Understanding the kinetics of the leaching process will allow industry to refine production of catalysts for optimum manufacturing time while knowledge of leaching dynamics of powders produced by different manufacturing techniques will allow further tailoring of catalytic materials.
Dissociative adsorption of CO2 on flat, stepped, and kinked Cu surfaces
Authors: Muttaqien Fahdzi , Hamamoto Yuji , Inagaki Kouji , Morikawa Yoshitada
Published: July 2014

We studied the dissociative adsorption of CO2 to CO + O on the Cu(111), Cu(221), Cu(211), and Cu(11 5 9) surfaces by using state-of-the-art density functional theory (DFT) within a generalized gradient approximation (GGA) and van der Waals density functional (vdW-DF) calculations. The activation energy for CO2 dissociation on the flat Cu(111) surface is 1.33 eV. The activation energies on stepped and kinked surfaces are 1.06 eV, 0.67 eV, and 1.02 eV for the Cu(221), Cu(211), and Cu(11 5 9) surfaces, respectively. Even though the activation energy is 0.66 eV lower on the stepped Cu(211) surface than on the flat Cu(111) surface, we conclude that CO2 does not dissociate on “ideal” flat, stepped, or kinked Cu surfaces at low temperature. We attribute the discrepancy between our theoretical results and experimentally observed CO2 dissociation on stepped Cu surfaces below 150 K to other factors such as effects of Cu adatoms, gas phase or condensed CO2 molecules, or interaction with other gas phase molecules.
Affine Kac-Moody symmetric spaces related with $A_{1}^{(1)}\hbox{,}\, A_{2}^{(1)}\hbox{,}\, A_{2}^{(2)}$A1(1),A2(1),A2(2)
Authors: Nayak Saudamini , Pati K. C.
Published: July 2014

Symmetric spaces associated with Lie algebras and Lie groups which are Riemannian manifolds have recently got a lot of attention in various branches of Physics for their role in classical/quantum integrable systems, transport phenomena, etc. Their infinite dimensional counter parts have recently been discovered which are affine Kac-Moody symmetric spaces. In this paper we have (algebraically) explicitly computed the affine Kac-Moody symmetric spaces associated with affine Kac-Moody algebras \documentclass[12pt]{minimal}\begin{document}$A_{1}^{(1)}, A_{2}^{(1)}, A_{2}^{(2)}$\end{document}A1(1),A2(1),A2(2). We hope these types of spaces will play similar roles as that of symmetric spaces in many physical systems.
An easy-to-fabricate low-temperature TiO2 electron collection layer for high efficiency planar heterojunction perovskite solar cells
Authors: Conings B. , Baeten L. , Jacobs T. , Dera R. , D’Haen J. , Manca J. , Boyen H.-G.
Published: July 2014

Organometal trihalide perovskite solar cells arguably represent the most auspicious new photovoltaic technology so far, as they possess an astonishing combination of properties. The impressive and brisk advances achieved so far bring forth highly efficient and solution processable solar cells, holding great promise to grow into a mature technology that is ready to be embedded on a large scale. However, the vast majority of state-of-the-art perovskite solar cells contains a dense TiO2 electron collection layer that requires a high temperature treatment (>450 °C), which obstructs the road towards roll-to-roll processing on flexible foils that can withstand no more than ∼150 °C. Furthermore, this high temperature treatment leads to an overall increased energy payback time and cumulative energy demand for this emerging photovoltaic technology. Here we present the implementation of an alternative TiO2 layer formed from an easily prepared nanoparticle dispersion, with annealing needs well within reach of roll-to-roll processing, making this technology also appealing from the energy payback aspect. Chemical and morphological analysis allows to understand and optimize the processing conditions of the TiO2 layer, finally resulting in a maximum obtained efficiency of 13.6% for a planar heterojunction solar cell within an ITO/TiO2/CH3NH3PbI3-xClxpoly(3-hexylthiophene)/Ag architecture.
Noise performance of magneto-inductive cables
Authors: Wiltshire M. C. K. , Syms R. R. A.
Published: July 2014

Magneto-inductive (MI) waveguides are metamaterial structures based on periodic arrangements of inductively coupled resonant magnetic elements. They are of interest for power transfer, communications and sensing, and can be realised in a flexible cable format. Signal-to-noise ratio is extremely important in applications involving signals. Here, we present the first experimental measurements of the noise performance of metamaterial cables. We focus on an application involving radiofrequency signal transmission in internal magnetic resonance imaging (MRI), where the subdivision of the metamaterial cable provides intrinsic patient safety. We consider MI cables suitable for use at 300 MHz during 1H MRI at 7 T, and find noise figures of 2.3–2.8 dB/m, together with losses of 3.0–3.9 dB/m, in good agreement with model calculations. These values are high compared to conventional cables, but become acceptable when (as here) the environment precludes the use of continuous conductors. To understand this behaviour, we present arguments for the fundamental performance limitations of these cables.
Importance of growth direction in mid-infrared quantum cascade lasers
Authors: Bouzi Pierre M. , Chiu YenTing , Deutsch Christoph , Dikmelik Yamac , Song Yu , Tokranov Vadim , Oktyabrsky Serge , Gmachl Claire
Published: July 2014

We report on the effect of growth direction on the performance of mid-infrared Quantum Cascade lasers. The design used has a symmetric active core, capable of operating under both negative and positive polarities, which allows to test for residual growth asymmetries such as interface roughness and dopant migration. Calculations of scattering lifetimes from interface roughness and ionized impurities suggest a dominant contribution from the former, with devices biased positively averaging ∼15% larger broadening and ∼50% shorter upper state lifetime than negatively biased devices. Experimental results for positively biased devices show at least 30% larger broadening and 35% lower electroluminescence peak intensity than those biased negatively, in good agreement with the modeling results.
In situ anodization of aluminum surfaces studied by x-ray reflectivity and electrochemical impedance spectroscopy
Authors: Bertram F. , Zhang F. , Evertsson J. , Carlà F. , Pan J. , Messing M. E. , Mikkelsen A. , Nilsson J.-O. , Lundgren E.
Published: July 2014

We present results from the anodization of an aluminum single crystal [Al(111)] and an aluminum alloy [Al 6060] studied by in situ x-ray reflectivity, in situ electrochemical impedance spectroscopy and ex situ scanning electron microscopy. For both samples, a linear increase of oxide film thickness with increasing anodization voltage was found. However, the slope is much higher in the single crystal case, and the break-up of the oxide film grown on the alloy occurs at a lower anodization potential than on the single crystal. The reasons for these observations are discussed as are the measured differences observed for x-ray reflectivity and electrochemical impedance spectroscopy.
Understanding dynamic percolation mechanisms in carbonaceous polymer nanocomposites through impedance spectroscopy: Experiments and modeling
Authors: Combessis A. , Charvin N. , Allais A. , Fournier J. , Flandin L.
Published: July 2014

Dynamic percolation refers to the impressive increase in conductivity in polymers filled with a constant filler content as a function of annealing time. We present a detailed study of the driving forces for this phenomenon. The organization of carbon nanotubes in a polymer melt is probed with a.c. conductivity. In contrast with the static percolation studied as a function of the filler content, two peaks are observed in the relative permittivity. We show that this new feature results from two distinct filler auto assembly mechanisms. The first one is ascribed to the relaxation of macromolecules and could be eliminated using the proper thermal treatment. The second mechanism is observed later in time. It is likely to correspond to a diffusion process of the carbonaceous filler similar to a phase separation. A phenomenological model is finally proposed to describe the changes in dispersion and distribution states with annealing time.
An interconnection protection design for the interface of alternating current microgrids
Authors: Huang Wentao , Tai Nengling , Zheng Xiaodong
Published: July 2014

The interface of AC microgrids plays an important part in implementing the flexible operation modes. It always manages the disconnection and reconnection between microgrids and the host distribution networks. This study proposes a new protection design interconnection protection (IP), for the interface of microgrids especially the multiple and large-scale ones. IP is intended to decouple interconnected subsystems to prevent disturbances or faults from damaging the both subsystems. IP can be classified into facility IP, circuit IP, and utility IP corresponding to the microgrid served. The deployments, features, and protection schemes of different IPs are analyzed according to the operation characteristics and requirements of the typical microgrid in IEEE Std 1547.4. Facility IP detects faults and disturbances by monitoring the power quality at the point of common coupling. Circuit IP and utility IP have alternative schemes, for example, current differential protection, distance protection, and overcurrent protection. A fault-direction-judgment overcurrent method is proposed for their overlap protection zone. Besides, a time-grading method is used to ensure the coordination of the IPs in the large-scale microgrid. The effectiveness of the proposed designs and protection schemes are demonstrated by the simplified microgrid in IEEE Std 1547.4.
Temperature dependence of the Raman spectra of polycrystalline graphene grown by chemical vapor deposition
Authors: Hosoya Nagisa , Akaho Yosuke , Inoue Miki , Sahoo Satyaprakash , Tachibana Masaru
Published: July 2014

The temperature dependence of the Raman spectra in the temperature range between 298 and 673 K was investigated for polycrystalline monolayer graphene films with defects, such as domain boundaries, synthesized by chemical vapor deposition. The Raman frequencies of G and 2D bands monotonically decrease with increasing temperature. The reversible change in the band frequencies is observed during thermal cycling after the first heating. From the reversible change, the temperature coefficients of G and 2D band frequencies are estimated to be −0.024 and −0.043 cm−1/K, respectively. These values are small compared with those for mechanically exfoliated ones without defect reported previously. Furthermore, the magnitude of the temperature coefficient of the G band decreases with increasing defect density. The smaller temperature coefficients can be explained by the suppression of anharmonic phonon interactions due to the defects.
Investigations of coupling acoustic matching in multilayer acoustic structures
Authors: Zhang Hui , Liu Zhao-Qun , Jiang Guo-zhu , Zhang Shu-yi , Fan Li
Published: July 2014

The coupling acoustic matching is investigated to realize acoustic sensors with a microfluidic channel, in which two overlap layers couple three local quarter-wavelength transmission elements. Provided that the reflecting waves from both sides of each overlap layer satisfy destructive interferences, most acoustic energy can be transmitted. Especially, the microfluidic channel is sensitive to realize a function of the acoustic matching, which could induce effects of an approximate half-wavelength transmission and much acoustic dissipation. With an optimized design, the detections of liquid properties with a high quality factor 300 in liquid environment, and a mass sensitivity of 95 kHz mm2/ng are obtained.
In vivo, label-free, three-dimensional quantitative imaging of liver surface using multi-photon microscopy
Authors: Zhuo Shuangmu , Yan Jie , Kang Yuzhan , Xu Shuoyu , Peng Qiwen , So Peter T. C. , Yu Hanry
Published: July 2014

Various structural features on the liver surface reflect functional changes in the liver. The visualization of these surface features with molecular specificity is of particular relevance to understanding the physiology and diseases of the liver. Using multi-photon microscopy (MPM), we have developed a label-free, three-dimensional quantitative and sensitive method to visualize various structural features of liver surface in living rat. MPM could quantitatively image the microstructural features of liver surface with respect to the sinuosity of collagen fiber, the elastic fiber structure, the ratio between elastin and collagen, collagen content, and the metabolic state of the hepatocytes that are correlative with the pathophysiologically induced changes in the regions of interest. This study highlights the potential of this technique as a useful tool for pathophysiological studies and possible diagnosis of the liver diseases with further development.
Seasonal changes in the body surface temperature of Hanwoo (Bos taurus coreanae) steers
Authors: Kim N. Y. , Kim S. J. , Park J. H. , Oh M. R. , Jang S. Y. , Kim D. H. , Sung S. H. , Jeon B. T. , Moon S. H.
Published: July 2014

The present study aimed to gather basic information on measuring body surface temperature (BST) of cattle by using infrared thermography (IRT) and find out whether BST measurement is a useful method to detect thermal balance of livestock. Twenty-seven Hanwoo steers were examined in a field trial. The BST of five body regions (eye, nose, horn, ear, rear) was measured five times daily, with three replicates, during 3 days each season. Body surface temperature of cattle is directly affected by ambient temperature and humidity, and showed different ranges for each region. The BSTs of nose, horns and ears were significantly (P < 0.05) lower than those of eyes and rear area. Rear-area BST was significantly lower than eye-area BST when the ambient temperature was low (P < 0.05). Eye BST (EBST) was highest (P < 0.05) and the least variable of all BSTs measured. Therefore, the eye area of cattle was the most thermostable part of the body. There were significant (P < 0.05) differences among seasonal EBSTs of steers. The EBST range was highest in the summer (37.9–42.2°C), followed by autumn (34.3–37.4°C), spring (33.8–36.5°C) and winter (29.8–32.6°C). During extreme cold, EBST showed a large standard deviation. During conditions of extreme heat, EBST was above the average body temperature of cattle. The results of the present study indicated that BST well reflects the thermal circumstances surrounding animals and may be used as one of the effective tools for precision cattle farming.
The acute effect of addition of nitrate on in vitro and in vivo methane emission in dairy cows
Authors: Lund P. , Dahl R. , Yang H. J. , Hellwing A. L. F. , Cao B. B. , Weisbjerg M. R.
Published: July 2014

The effects of a 24-h administration of a ration high in nitrate (20 g/kg DM) on DM intake and enteric gas production in lactating dairy cows as well as the effect of different doses of nitrate on in vitro fermentation were studied. Nitrate reduced in vivo methane (CH4) production by 31%, and CH4 production increased again when nitrate supplementation was stopped. A similar effect was found when relating CH4 to carbon dioxide, and to DM intake. Addition of nitrate was followed by increased hydrogen production, which decreased again when nitrate was stopped. Nitrate addition did not affect in vitro rumen fermentation in terms of DM degradability, pH, ammonia nitrogen, microbial protein and volatile fatty acid production, but it decreased gas production with longer initial delay time before onset of gas production and lower gas production rate. Nitrate added at 7–20 g/kg ration DM significantly decreased net initial (0–12 h) CH4 production by 10–16%, although no further depression was observed afterwards.
The Synthesis and Structural Characterization of Peralkylated Triguanide Superbases
Authors: Štrukil Vjekoslav , Lekšić Edislav , Meštrović Ernest , Eckert-Maksić Mirjana
Published: July 2014

Organic superbases derived from a peralkylated triguanide framework have been synthesized in a coupling reaction between monosubstituted guanidines and a Vilsmeier salt. Single crystal X-ray diffraction analysis of the chloride salt allowed the structural characterization of the benzyl derivative for the first time and revealed an effective delocalization of the positive charge despite significant distortion of the triguanide cation planarity. With the calculated gas phase basicity ranging from 262 to 265 kcal mol–1 and pKa values in acetonitrile between 28 and 30, these compounds have been evaluated as potential organocatalysts in the transesterification reaction of vegetable oil.
Predictive energy landscapes for folding α-helical transmembrane proteins
Authors: Kim Bobby L. , Schafer Nicholas P. , Wolynes Peter G.
Published: July 2014

Significance

The understanding of how membrane proteins fold pales in comparison with the understanding of globular protein folding. This discrepancy is partly due to the fact that membrane proteins are difficult to work with experimentally. In turn, the lack of high-quality experimental data has caused modeling of membrane proteins to lag behind. Also, the extent to which the translocon assists transmembrane domains in folding is unclear. The number of experimentally determined membrane protein structures has recently increased, and we may now be at the stage where it has become possible to derive transferable simulation models for studying transmembrane protein folding. We describe the optimization of one such model and its application to predicting helical packings within the native topology.
Molecular extraction in single live cells by sneaking in and out magnetic nanomaterials
Authors: Yang Zhen , Deng Liangzi , Lan Yucheng , Zhang Xiaoliu , Gao Zhonghong , Chu Ching-Wu , Cai Dong , Ren Zhifeng
Published: July 2014

Significance

Current technical barriers in molecular sampling compromise the biomedical research regarding the diversity of cellular background. Usually hundreds and thousands of cells are lysed to release their contents. As such, the differences among individual cells are averaged out. The progressive cellular information can only be obtained by analysis of cells terminated at sequential time points, except by using external fluorescent and chemical labels that may interfere with pathways. We used biocompatible magnetic nanostructures to extract biomolecules from live cells. Nanomaterials were sneaked into and out of the cells, carrying with them molecules across the cell membrane without a significant impact on cell viability or proliferation. Our research suggests a previously unidentified avenue of intracellular interrogation to accurately capture the diversity of molecular information.
Essential normality and the decomposability of homogeneous submodules
Authors: Kennedy Matthew
Published: July 2014

We establish the essential normality of a large new class of homogeneous submodules of the finite rank

d
d

-shift Hilbert module. The main idea is a notion of essential decomposability that determines when a submodule can be decomposed into the algebraic sum of essentially normal submodules. We prove that every essentially decomposable submodule is essentially normal, and introduce methods for establishing that a submodule is essentially decomposable. It turns out that many submodules have this property. We prove that many of the submodules considered by other authors are essentially decomposable, and in addition establish the essential decomposability of a large new class of homogeneous submodules. Our results support Arveson’s conjecture that every homogeneous submodule of the finite rank

d
d

-shift Hilbert module is essentially normal.
Spectral stability of periodic wave trains of the Korteweg-de Vries/Kuramoto-Sivashinsky equation in the Korteweg-de Vries limit
Authors: Johnson Mathew , Noble Pascal , Rodrigues L. , Zumbrun Kevin
Published: July 2014

We study the spectral stability of a family of periodic wave trains of the Korteweg-de Vries/Kuramoto-Sivashinsky equation
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="partial-differential Subscript t Baseline v plus v partial-differential Subscript x Baseline v plus partial-differential Subscript x Superscript 3 Baseline v plus delta left-parenthesis partial-differential Subscript x Superscript 2 Baseline v plus partial-differential Subscript x Superscript 4 Baseline v right-parenthesis equals 0 comma">

∂
t

v
+
v

∂
x

v
+

∂
x
3

v
+
δ

(

∂
x
2

v
+

∂
x
4

v
)

=
0
,

\partial _t v+v\partial _x v+\partial _x^3 v+\delta \left (\partial _x^2 v +\partial _x^4 v\right )=0,

δ
>
0

\delta >0

, in the Korteweg-de Vries limit

δ
→
0

\delta \to 0

, a canonical limit describing small-amplitude weakly unstable thin film flow. More precisely, we carry out a rigorous singular perturbation analysis reducing the problem of spectral stability in this limit to the validation of a set of three conditions, each of which have been numerically analyzed in previous studies and shown to hold simultaneously on a non-empty set of parameter space. The main technical difficulty in our analysis, and one that has not been previously addressed by any authors, is that of obtaining a useful description for

0
>
δ
≪
1

0>\delta \ll 1

of the spectrum of the associated linearized operators in a sufficiently small neighborhood of the origin in the spectral plane. This modulational stability analysis is particularly interesting, relying on direct calculations of a reduced periodic Evans function and using in an essential way an analogy with hyperbolic relaxation theory at the level of the associated Whitham modulation equations. A second technical difficulty is the exclusion of high-frequency instabilities lying between the

O

(
1
)

\mathcal {O}(1)

regime treatable by classical perturbation methods and the

≳

δ

−
1

\gtrsim \delta ^{-1}

regime excluded by parabolic energy estimates.
On finite additive 2-bases
Authors: Habsieger Laurent
Published: July 2014

For a positive integer

N
N

, a set

B

\mathcal {B}

of integers from

{
0
,
1
,
…
,
N
−
1
}

\{0,1,\dots ,N-1\}

is called an additive

2
2

-basis for

N
N

if every integer

n
∈
{
0
,
1
,
…
,
N
−
1
}

n\in \{0,1,\dots ,N-1\}

may be represented as the sum of

2
2

elements of

B

\mathcal {B}

. We discuss the methods used to estimate the minimal size of an additive

2
2

-basis for

N
N

. We provide new examples to enrich this survey, which give good bounds. For instance, we slightly improve on the current record, from

0.46972
0.46972

to

0.46906
0.46906

.
Wigner-von Neumann type perturbations of periodic Schrödinger operators
Authors: Lukic Milivoje , Ong Darren
Published: July 2014

We study decaying oscillatory perturbations of periodic Schrödinger operators on the half line. More precisely, the perturbations we consider satisfy a generalized bounded variation condition at infinity and an

L
p

L^p

decay condition. We show that the absolutely continuous spectrum is preserved, and give bounds on the Hausdorff dimension of the singular part of the resulting perturbed measure. Under additional assumptions, we instead show that the singular part embedded in the essential spectrum is contained in an explicit countable set. Finally, we demonstrate that this explicit countable set is optimal. That is, for every point in this set there is an open and dense class of periodic Schrödinger operators for which an appropriate perturbation will result in the spectrum having an embedded eigenvalue at that point.
Drosophilapericentrin requires interaction with calmodulin for its function at centrosomes and neuronal basal bodies but not at sperm basal bodies
Authors: Galletta Brian J. , Guillen Rodrigo X. , Fagerstrom Carey J. , Brownlee Chris W. , Lerit Dorothy A. , Megraw Timothy L. , Rogers Gregory C. , Rusan Nasser M.
Published: July 2014

Pericentrin is a critical centrosomal protein required for organizing pericentriolar material (PCM) in mitosis. Mutations in pericentrin cause the human genetic disorder Majewski/microcephalic osteodysplastic primordial dwarfism type II, making a detailed understanding of its regulation extremely important. Germaine to pericentrin's function in organizing PCM is its ability to localize to the centrosome through the conserved C-terminal PACT domain. Here we use Drosophila pericentrin-like-protein (PLP) to understand how the PACT domain is regulated. We show that the interaction of PLP with calmodulin (CaM) at two highly conserved CaM-binding sites in the PACT domain controls the proper targeting of PLP to the centrosome. Disrupting the PLP-CaM interaction with single point mutations renders PLP inefficient in localizing to centrioles in cultured S2 cells and Drosophila neuroblasts. Although levels of PCM are unaffected, it is highly disorganized. We also demonstrate that basal body formation in the male testes and the production of functional sperm does not rely on the PLP-CaM interaction, whereas production of functional mechanosensory neurons does.
Regulation of spindle pole body assembly and cytokinesis by the centrin-binding protein Sfi1 in fission yeast
Authors: Lee I-Ju , Wang Ning , Hu Wen , Schott Kersey , Bähler Jürg , Giddings Thomas H. , Pringle John R. , Du Li-Lin , Wu Jian-Qiu
Published: July 2014

Centrosomes play critical roles in the cell division cycle and ciliogenesis. Sfi1 is a centrin-binding protein conserved from yeast to humans. Budding yeast Sfi1 is essential for the initiation of spindle pole body (SPB; yeast centrosome) duplication. However, the recruitment and partitioning of Sfi1 to centrosomal structures have never been fully investigated in any organism, and the presumed importance of the conserved tryptophans in the internal repeats of Sfi1 remains untested. Here we report that in fission yeast, instead of doubling abruptly at the initiation of SPB duplication and remaining at a constant level thereafter, Sfi1 is gradually recruited to SPBs throughout the cell cycle. Like an sfi1Δ mutant, a Trp-to-Arg mutant (sfi1-M46) forms monopolar spindles and exhibits mitosis and cytokinesis defects. Sfi1-M46 protein associates preferentially with one of the two daughter SPBs during mitosis, resulting in a failure of new SPB assembly in the SPB receiving insufficient Sfi1. Although all five conserved tryptophans tested are involved in Sfi1 partitioning, the importance of the individual repeats in Sfi1 differs. In summary, our results reveal a link between the conserved tryptophans and Sfi1 partitioning and suggest a revision of the model for SPB assembly.
Proinflammatory cytokine-induced tight junction remodeling through dynamic self-assembly of claudins
Authors: Capaldo Christopher T. , Farkas Attila E. , Hilgarth Roland S. , Krug Susanne M. , Wolf Mattie F. , Benedik Jeremy K. , Fromm Michael , Koval Michael , Parkos Charles , Nusrat Asma
Published: July 2014

Tight junctions (TJs) are dynamic, multiprotein intercellular adhesive contacts that provide a vital barrier function in epithelial tissues. TJs are remodeled during physiological development and pathological mucosal inflammation, and differential expression of the claudin family of TJ proteins determines epithelial barrier properties. However, the molecular mechanisms involved in TJ remodeling are incompletely understood. Using acGFP-claudin 4 as a biosensor of TJ remodeling, we observed increased claudin 4 fluorescence recovery after photobleaching (FRAP) dynamics in response to inflammatory cytokines. Interferon γ and tumor necrosis factor α increased the proportion of mobile claudin 4 in the TJ. Up-regulation of claudin 4 protein rescued these mobility defects and cytokine-induced barrier compromise. Furthermore, claudins 2 and 4 have reciprocal effects on epithelial barrier function, exhibit differential FRAP dynamics, and compete for residency within the TJ. These findings establish a model of TJs as self-assembling systems that undergo remodeling in response to proinflammatory cytokines through a mechanism of heterotypic claudin-binding incompatibility.
SERCaMP: a carboxy-terminal protein modification that enables monitoring of ER calcium homeostasis
Authors: Henderson Mark J. , Wires Emily S. , Trychta Kathleen A. , Richie Christopher T. , Harvey Brandon K.
Published: July 2014

Endoplasmic reticulum (ER) calcium homeostasis is disrupted in diverse pathologies, including neurodegeneration, cardiovascular diseases, and diabetes. Temporally defining calcium dysregulation during disease progression, however, has been challenging. Here we describe secreted ER calcium-monitoring proteins (SERCaMPs), which allow for longitudinal monitoring of ER calcium homeostasis. We identified a carboxy-terminal modification that is sufficient to confer release of a protein specifically in response to ER calcium depletion. A Gaussia luciferase (GLuc)–based SERCaMP provides a simple and sensitive method to monitor ER calcium homeostasis in vitro or in vivo by analyzing culture medium or blood. GLuc-SERCaMPs revealed ER calcium depletion in rat primary neurons exposed to various ER stressors. In vivo, ER calcium disruption in rat liver was monitored over several days by repeated sampling of blood. Our results suggest that SERCaMPs will have broad applications for the long-term monitoring of ER calcium homeostasis and the development of therapeutic approaches to counteract ER calcium dysregulation.
Inferring population structure and relationship using minimal independent evolutionary markers in Y-chromosome: a hybrid approach of recursive feature selection for hierarchical clustering
Authors: Srivastava Amit Kumar , Chopra Rupali , Ali Shafat , Aggarwal Shweta , Vig Lovekesh , Koul Bamezai Rameshwar Nath
Published: July 2014

Inundation of evolutionary markers expedited in Human Genome Project and 1000 Genome Consortium has necessitated pruning of redundant and dependent variables. Various computational tools based on machine-learning and data-mining methods like feature selection/extraction have been proposed to escape the curse of dimensionality in large datasets. Incidentally, evolutionary studies, primarily based on sequentially evolved variations have remained un-facilitated by such advances till date. Here, we present a novel approach of recursive feature selection for hierarchical clustering of Y-chromosomal SNPs/haplogroups to select a minimal set of independent markers, sufficient to infer population structure as precisely as deduced by a larger number of evolutionary markers. To validate the applicability of our approach, we optimally designed MALDI-TOF mass spectrometry-based multiplex to accommodate independent Y-chromosomal markers in a single multiplex and genotyped two geographically distinct Indian populations. An analysis of 105 world-wide populations reflected that 15 independent variations/markers were optimal in defining population structure parameters, such as FST, molecular variance and correlation-based relationship. A subsequent addition of randomly selected markers had a negligible effect (close to zero, i.e. 1 × 10−3) on these parameters. The study proves efficient in tracing complex population structures and deriving relationships among world-wide populations in a cost-effective and expedient manner.
Strong mutator phenotype drives faster adaptation from growth on glucose to growth on acetate in Salmonella
Authors: Le Bars Hervé , Bonnaure-Mallet Martine , Barloy-Hubler Frédérique , Jolivet-Gougeon Anne , Bousarghin Latifa
Published: July 2014

The metabolic adaptation of strong mutator strains was studied to better understand the link between the strong mutator phenotype and virulence. Analysis of the growth curves of isogenic strains of Salmonella, which were previously grown in M63 glucose media, revealed that the exponential phase of growth was reached earlier in an M63 acetate medium with strong mutator strains (mutated in mutS or in mutL) than with normomutator strains (P<0.05). Complemented strains confirmed the direct role of the strong mutator phenotype in this faster metabolic adaptation to the assimilation of acetate. In a mixed cell population, proliferation of strong mutators over normomutators was observed when the carbon source was switched from glucose to acetate. These results add to the sparse body of knowledge about strong mutators and highlight the selective advantage conferred by the strong mutator phenotype to adapt to a switch of carbon source in the environment. This work may provide clinically useful information given that there is a high prevalence of strong mutators among pathogenic strains of Salmonella and that acetate is the principal short chain fatty acid of the human terminal ileum and colon where Salmonella infection is localized.
Differential expression of metallothioneins in response to heavy metals and their involvement in metal tolerance in the symbiotic basidiomycete Laccaria bicolor
Authors: Reddy M. Sudhakara , Prasanna Lakshmi , Marmeisse R. , Fraissinet-Tachet L.
Published: July 2014

Cysteine-rich peptides such as metallothioneins (MTs) are involved in metal homeostasis and detoxification in many eukaryotes. We report the characterization and expression of two MT genes,LbMT1andLbMT2from the ectomycorrhizal fungusLaccaria bicolorunder metal stress conditions.LbMT1andLbMT2differ with respect to the length of the encoded peptides (58 versus 37 aa, respectively) and also by their expression patterns in response to metals. The expression levels of bothLbMT1andLbMT2increased as a function of increased external Cu concentration, the expression levels forLbMT2were always significantly higher compared with those ofLbMT1. OnlyLbMT1, but notLbMT2, responded to Cd supply in the range of 25–100 µM while Zn did not affect the transcription of eitherLbMT1orLbMT2. Both genes also responded to oxidative stress, but to a lesser extent compared to their responses to either Cu or Cd stress. Heterologous complementation assays in metal-sensitive yeast mutants indicated that bothLbMT1andLbMT2encode peptides capable of conferring higher tolerance to both Cu and Cd. The present study identifiedLbMTsas potential determinants of the response of this mycorrhizal fungus to Cu and Cd stress.
C. eleganswhole-genome sequencing reveals mutational signatures related to carcinogens and DNA repair deficiency
Authors: Meier Bettina , Cooke Susanna L. , Weiss Joerg , Bailly Aymeric P. , Alexandrov Ludmil B. , Marshall John , Raine Keiran , Maddison Mark , Anderson Elizabeth , Stratton Michael R. , Gartner Anton , Campbell Peter J.
Published: July 2014

Mutation is associated with developmental and hereditary disorders, aging, and cancer. While we understand some mutational processes operative in human disease, most remain mysterious. We usedCaenorhabditis eleganswhole-genome sequencing to model mutational signatures, analyzing 183 worm populations across 17 DNA repair-deficient backgrounds propagated for 20 generations or exposed to carcinogens. The baseline mutation rate inC. eleganswas approximately one per genome per generation, not overtly altered across several DNA repair deficiencies over 20 generations. Telomere erosion led to complex chromosomal rearrangements initiated by breakage–fusion–bridge cycles and completed by simultaneously acquired, localized clusters of breakpoints. Aflatoxin B1induced substitutions of guanines in a GpC context, as observed in aflatoxin-induced liver cancers. Mutational burden increased with impaired nucleotide excision repair. Cisplatin and mechlorethamine, DNA crosslinking agents, caused dose- and genotype-dependent signatures among indels, substitutions, and rearrangements. Strikingly, both agents induced clustered rearrangements resembling “chromoanasynthesis,” a replication-based mutational signature seen in constitutional genomic disorders, suggesting that interstrand crosslinks may play a pathogenic role in such events. Cisplatin mutagenicity was most pronounced inxpf-1mutants, suggesting that this gene critically protects cells against platinum chemotherapy. Thus, experimental model systems combined with genome sequencing can recapture and mechanistically explain mutational signatures associated with human disease.
PTSD in adults with intellectual disabilities: stabilisation during inpatient stay
Authors: Lise Bakken Trine , Gjersoe Vibeke , Matre Espen , Kristiansen Tone , Ro Arvid , Louise Tveter Anne , Helene Hoeidal Siv , Nikolai Kildahl Arvid
Published: July 2014

Purpose

– The purpose of this paper is to describe and discuss interventions of stabilisation of emotions and behaviour in adults with post-traumatic stress disorder (PTSD). This topic is understudied in persons with intellectual disability.

Design/methodology/approach

– The aim of this study was to investigate interventions of stabilisation in persons with more severe intellectual disability; i.e. persons with moderate or severe intellectual disabilities. Five patients in a specialised psychiatric inpatient unit for patients with intellectual disabilities were included. Information about treatment of the patients was collected through case files, observations, and interviews. The authors of this paper followed a training programme for trauma therapists in addition to the inpatient treatment of the five patients.

Findings

– Six main areas of stabilisation of emotions and behaviour were identified: validation, anxiety relief, treatment of depressed mood, increased mastering of daily activities, protection against anxiety triggers, and facilitated staff communication. Protection from anxiety triggers seems to be a core element of milieu therapy interventions. Interventions for neurotypical PTSD patients, such as exposure therapy may be contraindicated for patients with more severe intellectual disabilities.

Originality/value

– Research on interventions of stabilisation towards adults with more severe intellectual disabilities is still in its infancy. The case reports may help milieu therapists to facilitate interventions towards patients with moderate or severe intellectual disabilities.
Universal truths: can universally held cultural values inform the modern corporation?
Authors: L. Walls Judith , C. Triandis Harry
Published: July 2014

Purpose

– There are four criteria that people universally value: health, well-being, longevity, and environmental preservation. When these criteria are violated, a society becomes unsustainable. In order to preserve cultures, these four universal criteria therefore need to be taken into account. But nation states are no longer the dominant form of social organizing – corporations are. This raises questions about the role of corporations in preserving cultural values. How do corporations measure up to these four universal truths? Can corporations live up to these values, above and beyond financial performance, and does it matter? The paper aims to discuss these issues.

Design/methodology/approach

– Amidst a shifting trend toward vertical individualism which emphasizes personal needs, status, and hierarchy, the paper argues that the universal truths are more important than ever in the consideration of corporate social responsibility.

Findings

– The paper concludes that although most companies claim to be attending to social and environmental issues, the current form of corporate governing is largely incapable of optimizing the four universally held values.

Originality/value

– The authors present some examples of corporations and corporate forms that appear to be heading in the “right” direction, but highlight that challenges remain. Nevertheless, the cross-culture literature can help inform the future of the relationship between business, society, and the natural environment.
Coaching is key to SME success
Authors: Bell Gareth
Published: July 2014

Purpose

– The purpose of the paper is to provide an interview with Peter Boolkah.

Design/methodology/approach

– The paper discusses some of the current issues within the coaching industry.

Findings

– Boolkah answers questions on coaching philosophy, what attributes make a successful coach and how a business can make the most of a coach’s expertise.

Practical implications

– Provides insight and advice from a leading industry professional.
Improving e-learning outcomes through purposeful peer interactions: three helpful recommendations to ensure success
Authors: Yanson Regina
Published: July 2014

Purpose

– The purpose of this paper is to provide some guidelines to help organizations improve e-learning initiatives through the use of purposeful interactions among trainees.

Design/methodology/approach

– The recommendations suggested in this paper are based on a review of research that was conducted in the area of e-learning.

Findings

– The addition of quality online and face-to-face peer interactions may be a way to combat some of the major problems associated with training online. Decisions about just how meaningful interactions should be incorporated depend on the nature of the training program, what you hope to accomplish and your financial and time constraints.

Practical implications

– This paper provides helpful information for organizational leaders or managers who are interested in implementing e-learning initiatives or those looking for recommendations on how to improving current e-learning outcomes.

Originality/value

– This paper will be of value to those who are involved in organizational training and developmental initiatives. The recommendations discussed in this paper will help the reader address important questions regarding how to include purposeful interaction in e-learning initiatives.
Determinants of HADR mission success: exploring the experience of the Malaysian army
Authors: Idris Aida , Nizam Che Soh Saiful
Published: July 2014

Purpose

– The purpose of this paper is to empirically explore issues in humanitarian aid and disaster relief (HADR) missions and examine the effects of selected factors on mission success. The paper focusses on organisational perspectives of the Malaysian army due to their extensive experience in HADR operations.

Design/methodology/approach

– Interactions among three broad factors namely human resource, logistics and coordination, as well as their effects on mission performance, were examined. A qualitative approach was chosen because it allowed for an exploratory yet a more in-depth analysis of the issues.

Findings

– Results suggest that while the effects of logistics and coordination on mission success appear to be direct, human resource influences it in a more indirect manner. Additionally, from a military viewpoint, HADR teams are also challenged by factors which are less controllable such as public support and local infrastructure.

Research limitations/implications

– The study has contributed to knowledge by proposing a more refined model of HADR operations performance which highlights relationships not adequately studied before. Based on the model, a quantitative study can be undertaken in the future to determine the relative effect of each factor.

Practical implications

– Among the areas of HADR operations that will benefit from the study are human resource and cross-cultural management, communication and interpersonal relations and information technology.

Originality/value

– Military perspectives of HADR missions are shared in the paper, which enrich current understanding of issues faced in such operations. The paper should also serve as an impetus for greater empirical research among scholars concerned with organisational perspectives in HADR operations performance.
What makes disaster donors different from non-donors
Authors: Nogami Tatsuya
Published: July 2014

Purpose

– The purpose of this paper is to explore what would make disaster donors different from non-donors, with particular attention paid to differences in two forms of donations: the monetary donation that directly benefits the beneficiary and the charitable donation that is used by charitable organizations to support their disaster relief activities. Differences in the perceived effectiveness of other disaster relief activities, skepticism about charitable organizations, disaster experience, disaster preparedness, and disaster insight were also examined between the two groups.

Design/methodology/approach

– A total of 300 Japanese participants were asked to complete a14-item questionnaire online. A series of comparative analyses were conducted to examine differences between donors and non-donors in the questionnaire items.

Findings

– Although non-donors evaluated the effectiveness of the monetary donation more positively than the charitable donation, donors evaluated the effectiveness of all the disaster relief activities more positively than non-donors. Moreover, donors were more prepared for disasters and more insightful into the current situation of the disaster victims than non-donors.

Research limitations/implications

– Along with the internal and external factors previously found, disaster awareness may be a key to increasing people's intention to donate for disaster victims. Such awareness could be fostered through successful disaster education and appropriate media coverage of disasters.

Originality/value

– The findings that non-donors generally have a less positive view of disaster relief activities imply that non-donors may be less knowledgeable than donors about how charitable activities can work and benefit disaster victims.
Issues raised by nurses and midwives in a post-disaster Bantul community
Authors: Sugino Mire , Dwi Hapsari Elsi , Madyaningrum Ema , Haryant Fitri , Warsini Sri , Takada Satoshi , Matsuo Hiroya
Published: July 2014

Purpose

– Bantul in Central Java was the most severely damaged area by a devastating earthquake in May 2006. Even after being victims themselves, nurses and midwives at public health centers worked devotedly. The purpose of this paper is to identify the nurses’ and midwives’ perceptions and understanding of their roles, as well as the needs of training in disaster preparedness and management.

Design/methodology/approach

– Focus group discussions and questionnaire survey were conducted with 11 nurses and 11 midwives of public health centers in Bantul. Content analysis was applied to analyze transcripts of the focus group discussions and the responses to questionnaire.

Findings

– Health care for survivors and community were provided by highly committed health professionals supported in strong community resilience. Donors driven relief programs tended to be unorganized and insensitive for local health providers. Besides, organized disaster management trainings are strongly needed to develop disaster nursing and preparedness.

Research limitations/implications

– Embedded problems of local health system and current nursing practice were highlighted.

Originality/value

– Focus group discussions provided vital information that can and must be used to improve disaster response capabilities. Moreover, it was equally it is crucial to examine carefully what unfolded during post-disaster intervention.