bluuebunny/crossref_metadata_2025 huggingface dataset:
Applications of high throughput (combinatorial) methodologies to electronic, magnetic, optical, and energy-related materials
Authors: Green Martin L. , Takeuchi Ichiro , Hattrick-Simpers Jason R.
Published: June 2013

High throughput (combinatorial) materials science methodology is a relatively new research paradigm that offers the promise of rapid and efficient materials screening, optimization, and discovery. The paradigm started in the pharmaceutical industry but was rapidly adopted to accelerate materials research in a wide variety of areas. High throughput experiments are characterized by synthesis of a “library” sample that contains the materials variation of interest (typically composition), and rapid and localized measurement schemes that result in massive data sets. Because the data are collected at the same time on the same “library” sample, they can be highly uniform with respect to fixed processing parameters. This article critically reviews the literature pertaining to applications of combinatorial materials science for electronic, magnetic, optical, and energy-related materials. It is expected that high throughput methodologies will facilitate commercialization of novel materials for these critically important applications. Despite the overwhelming evidence presented in this paper that high throughput studies can effectively inform commercial practice, in our perception, it remains an underutilized research and development tool. Part of this perception may be due to the inaccessibility of proprietary industrial research and development practices, but clearly the initial cost and availability of high throughput laboratory equipment plays a role. Combinatorial materials science has traditionally been focused on materials discovery, screening, and optimization to combat the extremely high cost and long development times for new materials and their introduction into commerce. Going forward, combinatorial materials science will also be driven by other needs such as materials substitution and experimental verification of materials properties predicted by modeling and simulation, which have recently received much attention with the advent of the Materials Genome Initiative. Thus, the challenge for combinatorial methodology will be the effective coupling of synthesis, characterization and theory, and the ability to rapidly manage large amounts of data in a variety of formats.
Experimental and theoretical study of electronic structure of lutetium bi-phthalocyanine
Authors: Bidermane I. , Lüder J. , Boudet S. , Zhang T. , Ahmadi S. , Grazioli C. , Bouvet M. , Rusz J. , Sanyal B. , Eriksson O. , Brena B. , Puglia C. , Witkowski N.
Published: June 2013

Using Near Edge X-Ray Absorption Fine Structure (NEXAFS) Spectroscopy, the thickness dependent formation of Lutetium Phthalocyanine (LuPc2) films on a stepped passivated Si(100)2×1 reconstructed surface was studied. Density functional theory (DFT) calculations were employed to gain detailed insights into the electronic structure. Photoelectron spectroscopy measurements have not revealed any noticeable interaction of LuPc2 with the H-passivated Si surface. The presented study can be considered to give a comprehensive description of the LuPc2 molecular electronic structure. The DFT calculations reveal the interaction of the two molecular rings with each other and with the metallic center forming new kinds of orbitals in between the phthalocyanine rings, which allows to better understand the experimentally obtained NEXAFS results.
Near-ideal electrical properties of InAs/WSe2 van der Waals heterojunction diodes
Authors: Chuang Steven , Kapadia Rehan , Fang Hui , Chia Chang Ting , Yen Wen-Chun , Chueh Yu-Lun , Javey Ali
Published: June 2013

Here, we present the fabrication and electrical analysis of InAs/WSe2 van der Waals heterojunction diodes formed by the transfer of ultrathin membranes of one material upon another. Notably, InAs and WSe2 are two materials with completely different crystal structures, which heterojunction is inconceivable with traditional epitaxial growth techniques. Clear rectification from the n-InAs/p-WSe2 junction (forward/reverse current ratio >106) is observed. A low reverse bias current <10−12A/μm2 and ideality factor of ∼1.1 were achieved, suggesting near-ideal electrically active interfaces.
Convexity of quasi-entropy type functions: Lieb's and Ando's convexity theorems revisited
Authors: Hiai Fumio , Petz Dénes
Published: June 2013

Given a positive function f on (0, ∞) and a non-zero real parameter θ, we consider a function \documentclass[12pt]{minimal}\begin{document}$I_f^\theta (A,B,X)=\mathrm{Tr}\,X^*(f(L_AR_B^{-1})R_B)^{-\theta }(X)$\end{document}Ifθ(A,B,X)= Tr X*(f(LARB−1)RB)−θ(X) in three matrices A, B > 0 and X. This generalizes the notion of monotone metrics on positive definite matrices, and in the literature θ = ±1 has been typical. We investigate how operator monotony of f is sufficient and/or necessary for joint convexity/concavity of \documentclass[12pt]{minimal}\begin{document}$I_f^\theta (A,B,X)$\end{document}Ifθ(A,B,X). Similar discussions are given for quasi-entropies and quantum skew informations.
Effects of the magnetic field direction and anisotropy on the interband light absorption of an asymmetric quantum dot
Authors: Khordad R.
Published: June 2013

In this paper, the direct interband transition and the threshold frequency of absorption in a two-dimensional anisotropic quantum dot are studied under the influence of a tilted external magnetic field. We first calculate the analytical wave functions and energy levels using a transformation to simplify the Hamiltonian of the system. Then, we obtain the analytical expressions for the light interband absorption coefficient and the threshold frequency of absorption as a function of the magnetic field, magnetic field direction, and anisotropy of the system. According to the results obtained from the present work, we find that (i) the absorption threshold frequency (ATF) increases when the magnetic field increases for all directions. (ii) When anisotropy is increased, ATF increases. (iii) At small anisotropy, the magnetic field direction has no important effect on the ATF. In brief, the magnetic field, magnetic field direction, and anisotropy play important roles in the ATF and absorption coefficient.
On phase diagrams of magnetic reconnection
Authors: Cassak P. A. , Drake J. F.
Published: June 2013

Recently, “phase diagrams” of magnetic reconnection were developed to graphically organize the present knowledge of what type, or phase, of reconnection is dominant in systems with given characteristic plasma parameters. Here, a number of considerations that require caution in using the diagrams are pointed out. First, two known properties of reconnection are omitted from the diagrams: the history dependence of reconnection and the absence of reconnection for small Lundquist number. Second, the phase diagrams mask a number of features. For one, the predicted transition to Hall reconnection should be thought of as an upper bound on the Lundquist number, and it may happen for considerably smaller values. Second, reconnection is never “slow,” it is always “fast” in the sense that the normalized reconnection rate is always at least 0.01. This has important implications for reconnection onset models. Finally, the definition of the relevant Lundquist number is nuanced and may differ greatly from the value based on characteristic scales. These considerations are important for applications of the phase diagrams. This is demonstrated by example for solar flares, where it is argued that it is unlikely that collisional reconnection can occur in the corona.
The fabrication of GaN-based nanorod light-emitting diodes with multilayer graphene transparent electrodes
Authors: Li Zhi , Kang Junjie , Zhang Yiyun , Liu Zhiqiang , Wang Liancheng , Lee Xiao , Li Xiao , Yi Xiaoyan , Zhu Hongwei , Wang Guohong
Published: June 2013

GaN-based nanorod light-emitting diodes (LEDs) with multilayer graphene (MLG) transparent electrodes have been fabricated. Two types of nano-LEDs with graphene on and under the metal pads are fabricated and their performances are investigated. And LEDs with graphene on the metal-pads exhibiting lower forward voltage and higher electroluminescence intensity are obtained. Using scanning electron microscope and Raman spectroscopy, we have demonstrated that graphene transferred after the metal deposition remains intact and has much less damages than graphene under the metal during the fabrication of LEDs with nanorods.
Investigation of carrier-carrier scattering effect on the performance of hot carrier solar cells with relaxation time approximation
Authors: Feng Y. , Patterson R. , Lin S. , Shrestha S. , Huang S. , Green M. , Conibeer G.
Published: June 2013

The performance of hot carrier solar cells has been analyzed using a model incorporating the relaxation times of the relevant electronic processes. The variations in the maximum efficiency as well as the carrier statistics are demonstrated according to different carrier-carrier scattering rates. The significant dependance of cell performances on Coulomb scattering properties is quantitatively demonstrated and explained by carrier depletion, asymmetric electron and hole statistics, and unmatched transmission properties for carrier extraction. The inter-relation between the electronic properties of the absorber material and the contact properties implies that an integrated design with both parts is required.
Hybrid microcavity humidity sensor
Authors: Mehrabani Simin , Kwong Philip , Gupta Malancha , Armani Andrea M.
Published: June 2013

This work presents an optical humidity sensing technique based on the combination of a whispering gallery mode microtoroidal cavity sensor and a nm-scale thick humidity-responsive polymer coating deposited via the initiated chemical vapor deposition process. As a result of the conformational change by the polymer in response to humidity, the sensitivity is increased by nearly two orders of magnitude in comparison to conventional refractometric sensing. Additionally, the dependence of the device performance on the film thickness is studied. Specifically, the thinner film enabled a faster response rate, yet a slower recovery rate, as compared to the thicker films.
The effect of the surface functionalization and the electrolyte concentration on the electrical conductance of silica nanochannels
Authors: Martins D. C. , Chu V. , Conde J. P.
Published: June 2013

It is known that the conductance of nanochannels as a function of electrolyte concentration deviates from a linearly proportional relationship and approaches a value independent of the concentration as the electrolyte concentration is lowered. Most of the proposed models account for this behavior by considering a constant surface charge density and an ideal electrolyte solution. However, at low electrolyte concentrations, the ideal electrolyte approximation is no longer valid because the ions that result from the atmospheric carbon dioxide dissolution in water dominate the ionic concentration. In this paper, arrays of silica nanochannels were electrically characterized via conductance measurements. The conductance at low salt concentrations is modeled by a variable surface charge model that accounts for all ionic species in solution. This model was used to determine the variable surface charge of the bare silica nanochannels as well as of chemically modified nanochannels. The model correctly predicted the variation of the nanochannel conductance observed after silane (aminopropyldimethylethoxysilane) functionalization and single-strand DNA immobilization. Finally, pH modification of bulk KCl solutions was employed as an alternative method of changing the surface charge of silica nanochannels. Surface charge calculated from conductance measurements performed at different bulk pH values confirmed that the surface charge of the silica nanochannel walls is sensitive to the H+ concentration.
Experimental study of micro electrical discharge machining discharges
Authors: Bragança I. M. F. , Rosa P. A. R. , Dias F. M. , Martins P. A. F. , Alves L. L.
Published: June 2013

Micro electrical discharge machining (μEDM) is an atmospheric-pressure plasma-assisted technology that uses point-to-plane discharges in liquid dielectrics to remove microscopic quantities of electrically conductive materials. In this work, an innovative μEDM prototype machine was specifically designed and fabricated to produce and control single spark discharges, thus, resolving the typical limitations of (multi-discharge) commercial machines. The work analyses the type of discharge and the micro-plasma electron-density values obtained for 0.5–38 μm gap sizes, 3–10 000 μs pulse durations, 75–250 V low breakdown voltages, and 1–20 A discharge currents, using different combinations of metallic electrodes in oil and in water. Results allow fitting, for micro-scale and low voltages, an empirical law between the maximum gap-size for breakdown, the breakdown voltage, and the effective stress-time. The electron density ne is obtained by optical emission spectroscopy diagnostics of the Hα-line Stark broadening (yielding ne∼1016−1017 cm−3, i.e., ionization degrees of ∼2×10−5−10−4) and by a semi-empirical resistive plasma model. The model uses the experimental values of several electrical and geometrical quantities, and of the gas pressure estimated as ∼60 bar−2 kbar from measurements of the plasma mechanical action, obtained using a force sensor. The quantitative information of this phenomenological study can assist the optimization of this micro-fabrication technique.
Giant low-temperature magnetostriction and spin-reorientation of polycrystalline alloy PrFe1.9
Authors: Tang Y. M. , Xie R. , Zhang L. , Gao J. L. , Chen L. Y. , Xia W. B. , Wang Y. , Tang S. L. , Du Y. W.
Published: June 2013

A remarkably giant intrinsic magnetostriction λ111 as high as 6700 ppm was found at 70 K in PrFe1.9 compound, which is much larger than the value of 5600 ppm predicted by single-ion theory. Change of the easy magnetization direction from [111] to [100] with decreasing temperature occurs between 30 and 70 K, which was verified by step-scanned {440} and {222} X-ray diffraction reflections. It was further demonstrated that this compound has a rhombohedral symmetry between 70 and 300 K, and a tetragonal symmetry between 15 and 30 K. Therefore, the magnetostrictive anomaly at low temperature may be interpreted by the spin reorientation transition of the compound. PrFe1.9 with high magnetostriction is a good candidate material for magnetostriction applications at low temperature.
Optical anisotropy in solvent-modified poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) and its effect on the photovoltaic performance of crystalline silicon/organic heterojunction solar cells
Authors: Liu Qiming , Imamura Takashi , Hiate Taiga , Khatri Ishwor , Tang Zeguo , Ishikawa Ryo , Ueno Keiji , Shirai Hajime
Published: June 2013

An investigation was carried out into the effect of uniaxial optical anisotropy in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) on the photovoltaic performance of crystalline Si/PEDOT:PSS heterojunction solar cells fabricated by spin coating using either a methanol (MeOH) solvent alone or using MeOH and ethylene glycol (EG) as cosolvents. Spectroscopic ellipsometry revealed that the extraordinary index of refraction increased by the use of the cosolvents. In contrast, the ordinary index of refraction indicated metallic properties and was almost independent of the concentration of MeOH or EG. The highest conductivity was found for a (PEDOT:PSS):(MeOH):(EG) weight ratio of 1:1:0.1, and this sample exhibited a relatively high power conversion efficiency of 11.23%. These findings suggest that the increase in the extraordinary index of refraction leads to an enhancement of the hole mobility in PEDOT:PSS, resulting in improved photovoltaic performance.
1% solar cells derived from ultrathin carbon nanotube photoabsorbing films
Authors: Shea Matthew J. , Arnold Michael S.
Published: June 2013

Using a carbon nanotube photoabsorbing film <5 nm in thickness, we demonstrate a 1% solar cell. Specifically, polymer wrapped, highly monochiral (7, 5) nanotubes are implemented in a bilayered heterojunction with acceptor C60. The nanotubes drive 63% of the conversion, several times stronger than previously demonstrated. Peak external quantum efficiency (QE) of 43% at the nanotube bandgap (1055 nm) and power conversion efficiency of 0.95% and 1.02% at 1.0 and 1.5 suns, respectively, are achieved. The high internal QE from the ultrathin layers suggests that nanostructured or multijunction cells exploiting multiple nanotube layers will be many times more efficient.
Evidence of an embedded vortex translation mode in flake-shaped ferromagnetic particle composites
Authors: Neige J. , Lepetit T. , Malléjac N. , Adenot-Engelvin A.-L. , Thiaville A. , Vukadinovic N.
Published: June 2013

A low-frequency resonance (sub-GHz) is observed in microwave permeability spectra of anisotropic flake-shaped ferromagnetic particle composites. The resonance frequency of this peak increases linearly with the saturation magnetization of flakes, their aspect ratio, and the amplitude of a perpendicular static magnetic field. In addition, this resonance becomes extinct for a perpendicular RF exciting magnetic field. These experimental features are reproduced by an analytical model of vortex dynamics which militates in favor of an assignment of this low-frequency signal as an embedded vortex translation mode within a multidomain magnetic structure.
The origins of polarimetric image contrast between healthy and cancerous human colon tissue
Authors: Novikova T. , Pierangelo A. , Manhas S. , Benali A. , Validire P. , Gayet B. , De Martino A.
Published: June 2013

Experimentally measured spectral Mueller matrix images of ex vivo human colon tissue revealed the contrast enhancement between healthy and cancerous zones of colon specimen compared to unpolarized intensity images. Cancer development starts with abnormal changes which being not yet visible macroscopically may alter the polarization of reflected light. We have shown with experiments and modeling that light scattering by small (sub wavelength) scatterers and light absorption (mainly due to blood hemoglobin) are the key factors for observed polarimetric image contrast. These findings can pave the way for the alternative optical technique for the monitoring and early detection of cancer.
Organophosphonates as model system for studying electronic transport through monolayers on SiO2/Si surfaces
Authors: Bora A. , Pathak A. , Liao K.-C. , Vexler M. I. , Kuligk A. , Cattani-Scholz A. , Meinerzhagen B. , Abstreiter G. , Schwartz J. , Tornow M.
Published: June 2013

We report electrical transport measurements made on alkylphosphonate self-assembled monolayers grown on nanometer-thin SiO2 on top of highly p-doped silicon. At small bias direct tunneling is characterized by a decay constant of β ≈ 0.7/carbon. At larger positive bias to the silicon (1.1–1.5 V) the current-voltage traces feature a prominent shoulder, reminiscent of a negative differential resistance. We attribute this feature to a significant reduction in trap-assisted tunneling, as supported by a simulation. Hence, organophosphonate monolayers are excellent model systems to study electrical transport through ordered structures; they also provide highly efficient electrical passivation of the SiO2/Si surface.
Band offsets and dielectric properties of the amorphous Si3N4/Si(100) interface: A first-principles study
Authors: Anh Pham T. , Li Tianshu , Nguyen Huy-Viet , Shankar Sadasivan , Gygi Francois , Galli Giulia
Published: June 2013

By combining classical and ab-initio simulations, we generated a structural model of an amorphous silicon nitride/silicon(100) interface and we investigated its electronic and dielectric properties from first principles. We computed the valence band offset using many-body perturbation theory, within the GW approximation, and we found results in good agreement with experiments. Based on the computed local band edges and dielectric constants, we estimate that bulk properties are recovered for nitride films with thickness larger than 6–7 Å.
High field terahertz pulse generation from plasma wakefield driven by tailored laser pulses
Authors: Chen Zi-Yu
Published: June 2013

A scheme to generate high field terahertz (THz) pulses by using tailored laser pulses interaction with a gas target is proposed. The laser wakefield based THz source is emitted from the asymmetric laser shape induced plasma transverse transient net currents. Particle-in-cell simulations show that THz emission with electric filed strength over 1 GV/cm can be obtained with incident laser at 1×1019 W/cm2 level, and the corresponding energy conversion efficiency is more than 10−4. The intensity scaling holds up to high field strengths. Such a source also has a broad tunability range in amplitude, frequency spectra, and temporal shape.
Changes in total soil organic carbon stocks and carbon fractions in sugarcane systems as affected by tillage and trash management in Queensland, Australia
Authors: Page K. L. , Bell M. , Dalal R. C.
Published: June 2013

The use of sugarcane trash (tops and residue) retention systems has been reported to lead to increases in total soil organic carbon (TOC) stocks. However, these increases have generally been small and confined to the top 0.05 m of the soil profile. It has been hypothesised that the amount of TOC sequestered could be increased if the intensive tillage that occurs at the end of a sugarcane ratoon cycle, which is known to decrease TOC, could be eliminated. This research examined the effect of no-till management and/or trash retention on four trial sites throughout Queensland, to assess the ability of this management to increase TOC stocks. Management effects on particulate organic carbon (POC), humus organic carbon (HOC), and resistant organic carbon (ROC) stocks were also assessed using mid-infrared spectroscopy. No significant changes in TOC, POC, HOC, or ROC were observed over either 0–0.1 or 0–0.3 m depth at any of the sites examined, when sites were considered as a whole. The results indicate that these management practices currently have limited capacity to increase TOC stocks on these soil types over 0–0.1 or 0–0.3 m depth for the purposes of carbon sequestration.
Body sizes, activity patterns and habitat relationships of the orange-naped snake (Furina ornata) (Serpentes : Elapidae) in the MacDonnell Ranges, Northern Territory
Authors: McDonald Peter J. , Luck Gary W. , Pavey Chris R. , Wassens Skye
Published: June 2013

Orange-naped snakes (Furina ornata) are small elapids that occur in tropical to arid regions throughout northern and central Australia. We report on the first field-based study of this species, investigating body sizes, activity patterns, and habitat use in the semiarid MacDonnell Ranges bioregion of central Australia. Using systematic road-cruising, we encountered 69 live F. ornata along a 77-km sealed road-transect over a 12-month period from August 2009 to July 2010. Based on measures of snout-to-vent length (SVL), we found that female F. ornata (mean SVL = 459 ± 6.3 (s.e.) mm; n = 16) were larger than males (SVL = 372 ± 25.2 (s.e.) mm; n = 44) (t = 4.7358, P < 0.0001), and that both sexes were larger than previously reported from museum specimens. Despite the extreme weather variability experienced in arid Australia, we found that activity patterns were not significantly related to temperature, rainfall or humidity, and F. ornata was active in all but the single coldest month of the year. The habitat-use analysis found that F. ornata was more likely to be recorded in areas with greater cover of hummock grass (Triodia spp.) and less cover of rocky outcrops or boulders. Hummock grasslands in arid Australia have an abundant and diverse skink fauna, which may attract F. ornata, whose diet consists primarily of diurnal skinks.
Multiplication operators on vector-valued function spaces
Authors: Duru Hülya , Kitover Arkady , Orhon Mehmet
Published: June 2013

Let

E
E

be a Banach function space on a probability measure space

(
Ω
,
Σ
,
μ
)
.

(\Omega ,\Sigma ,\mu ).

Let

X
X

be a Banach space and

E
(
X
)

E(X)

be the associated Köthe-Bochner space. An operator on

E
(
X
)

E(X)

is called a multiplication operator if it is given by multiplication by a function in

L

∞

(
μ
)
.

L^{\infty }(\mu ).

In the main result of this paper, we show that an operator

T
T

on

E
(
X
)

E(X)

is a multiplication operator if and only if

T
T

commutes with

L

∞

(
μ
)

L^{\infty }(\mu )

and leaves invariant the cyclic subspaces generated by the constant vector-valued functions in

E
(
X
)
.

E(X).

As a corollary we show that this is equivalent to

T
T

satisfying a functional equation considered by Calabuig, Rodríguez, and Sánchez-Pérez.
Inverse degree of an affine space triangular automorphism
Authors: Kawaguchi Shu
Published: June 2013

For any

Q

\mathbb {Q}

-algebra

R
R

and any triangular automorphism

f
:

R
N

→

R
N

f: R^N\to R^N

with Jacobian one on the affine space, we show that

deg
⁡
(

f

−
1

)

\deg (f^{-1})

is bounded from above by a constant depending only on

N
N

and

deg
⁡
(
f
)

\deg (f)

. This is seen as a generalization of a result by Furter on the affine plane. Our proof uses (a version of) Furter’s estimate on nilpotency indices and Abhyankar–Gurjar’s formal inversion formula. It follows that when the Jacobian of a triangular automorphism

f
:

R
N

→

R
N

f: R^N\to R^N

is not necessarily equal to one,

deg
⁡
(

f

−
1

)

\deg (f^{-1})

is bounded from above by a constant depending only on

N
N

,

deg
⁡
(
f
)

\deg (f)

and

deg
⁡
(
1

/

Jac
⁡
(
f
)
)

\deg (1/\operatorname {Jac}(f))

.
Oral immunization of mice with Saccharomyces cerevisiae expressing a neutralizing epitope of ApxIIA exotoxin from Actinobacillus pleuropneumoniae induces systemic and mucosal immune responses
Authors: Shin Min‐Kyoung , Lee Won‐Jung , Jung Myung Hwan , Cha Seung‐Bin , Shin Seung‐Won , Yoo Anna , Kim Dae‐Hyuk , Yoo Han Sang
Published: June 2013

An oral delivery system based on ApxIIA#5‐expressed on Saccharomyces cerevisiae was studied for its potential to induce immune responses in mice. Murine bone marrow‐derived dendritic cells (DCs) stimulated in vitro with ApxIIA#5‐expressed on S. cerevisiae upregulated the expression of maturation and activation markers, leading to production of tumor necrosis factor‐α, interleukin (IL)‐1β, IL‐12p70 and IL‐10. Presentation of these activated DCs to cluster of differentiation CD4+ T cells collected from mice that had been orally immunized with the ApxIIA#5‐expressed on S. cerevisiae elicited specific T‐cell proliferation. In addition, the orally immunized mice had stronger antigen‐specific serum IgG and IgA antibody responses and larger numbers of antigen‐specific IgG and IgA antibody‐secreting cells in their spleens, Peyer's patches and lamina propria than did those immunized with vector‐only S. cerevisiae or those not immunized. Furthermore, oral immunization induced T helper 1‐type immune responses mediated via increased serum concentrations of IgG2a and an increase predominantly of IFN‐γ‐producing cells in their spleens and lamina propria. Our findings suggest that surface‐displayed ApxIIA#5‐expressed on S. cerevisiae may be a promising candidate for an oral vaccine delivery system for eliciting systemic and mucosal immunity.
Isolation and characterization of probiotic properties of Lactobacilli isolated from rat fecal microbiota
Authors: Jena Prasant Kumar , Trivedi Disha , Thakore Kirati , Chaudhary Harshita , Giri Sib Sankar , Seshadri Sriram
Published: June 2013

The objective of the present study was to characterize lactobacilli isolates from the feces of male Wistar rats. Various physiological features of the candidate probiotic isolates were preliminarily investigated, including tolerance to simulated gastric juice and bile salts, antimicrobial activity, antibiotic susceptibility and in vitro aggregation. Based on their morphological and biochemical characteristics, four potential probiotic isolates (CS2, CS3, CS4, and CS7) were screened. The isolates showed good tolerance to stimulated gastric juice and bile salts. CS4 and CS7 exhibited strong antibacterial activities against the pathogens tested as assessed in neutral pH culture supernatants. All lactobacilli isolates were susceptible to all the tested antibiotics, except vancomycin. Moreover, the isolate CS4 and CS7 were found to possess stronger cell surface traits such as hydrophobicity, auto‐aggregation and co‐aggregation capacity. In addition, CS4 and CS7 had greater β‐galactosidase activities than the others. Biochemical tests and 16S rRNA gene sequencing confirmed that CS2, CS3, CS4 and CS7 are Lactobacillus intestinalis PJ2, L. sakei PJ3, L. helveticus PJ4, and L. plantarum PJ7, respectively. Based on the obtained results, L. helveticus PJ4 and L. plantarum PJ7 are ideal in vitro probiotic candidates and require further in vivo evaluation.
Influence of acute salinity changes on biochemical, hematological and immune characteristics of Fenneropenaeus indicus during white spot syndrome virus challenge
Authors: Vaseeharan Baskaralingam , Ramasamy Palaniappan , Wesley Samuel Godwin , Chen Jiann‐Chu
Published: June 2013

The present study reports the influence of salinity (5, 15, 25 and 35 g/L) on the biochemical and immune characteristics of Fenneropenaeus indicus challenged with 5. 5 × 104 copy number of white spot syndrome virus (WSSV). F. indicus that had been reared in 25 g/L, injected with WSSV and transferred to 5, 15, 25 (control) and 35 g/L were examined after 0–120 hrs for total hemocyte count (THC), phenoloxidase (PO) and respiratory burst (RB) activity and alkaline and acid phosphatase activities. It was concluded that F. indicus that had been transferred from 25 g/L to lower and higher salinity levels (5, 15 and 35 g/L) had poorer immune indices and decreased resistance against WSSV infection. After 120 hrs, the mortality rate in WSSV‐injected F. indicus experimental groups (5 and 35 g/L) was significantly higher than for F. indicus exposed to 25 and 15 g/L salinities. During the experimental period (0–120 hrs), biochemical variables, namely total protein, carbohydrate, and lipid concentrations, were measured in hemolymph of both experimental and control groups. Acute salinity changes induced an increase in protein variations across the tested salinity ranges in shrimp. After 24 hrs, THC and PO activity decreased significantly whereas RB, alkaline phosphatase and acid phosphatase activities increased in shrimps kept at the lower salinities of 5, 15 and 35 g/L.
Hard boundaries influence African wild dogs' diet and prey selection
Authors: Davies‐Mostert Harriet T. , Mills Michael G. L. , Macdonald David W.
Published: June 2013

Human‐mediated changes in habitat structure may disturb predator–prey relationships.

We investigated the influence of perimeter fences on the diet of a reintroduced population of African wild dogs Lycaon pictus Temminck 1820 in a 316 km2, fenced reserve in South Africa, by tracking radio‐collared individuals during hunting periods to determine dietary composition from observed kills.

Nutritional status of impala Aepyceros melampus and kudu Tragelaphus strepsiceros prey, as measured by the percentage of femur marrow fat, was significantly lower than that of unselectively culled individuals. This supports the hypothesis that wild dog predation is at least partially compensatory.

Fence‐impeded kills (those for which escape was deemed to be compromised by the fence) comprised 40·5% of kills (n = 316), and 54·1% of all edible biomass consumed. Compared with fence‐unimpeded kills, fence‐impeded kills comprised larger species (32·9 vs. 25·0 kg, W = 25667·0, P ≪ 0·001), older age classes for one prey category (female kudu: Fisher's exact test, P = 0·02, n = 65) and animals in better condition for adult impala males (Mann–Whitney, W = 111·0, P = 0·012, n = 28).

Fence‐impeded kills also provided greater catch per unit hunting effort (27·3 vs. 12·2 kg km−1; χ2 = 7·89, P = 0·005), resulting in longer interkill intervals. Movement of the pack towards the fence at the start of each hunting period suggested a decision to exploit the advantage that fences conferred for capturing prey.

Synthesis and applications. By enabling coursing predators to capture prey that would otherwise have escaped, fences may reduce the compensatory nature of predation, causing shifts in predator–prey dynamics that could influence the ability of small reserves to support such predators. The establishment of larger conservation areas to reduce perimeter‐to‐area ratios should be encouraged to limit the undesired effects of fences on predator–prey dynamics.
Experiences of occupational therapists returning to work after maternity leave
Authors: Parcsi Lisa , Curtin Michael
Published: June 2013

Background/aim

Returning to work after maternity leave can be a challenging, anxious and fraught experience for women, and has been portrayed in the literature as a generally negative experience. Interestingly, although occupational therapists were predominantly women, no research was found focussing on their experiences of returning to work after maternity leave. The aim of this research was to gain an insight into occupational therapists' experiences of returning to work following maternity leave.

Methods

Principles of interpretive phenomenological analysis were used to explore the individual experiences of six Australian occupational therapists returning to work after a period of maternity leave. Individual semi‐structured interviews lasting up to 90 minutes were conducted. Interviews were audio‐recorded, transcribed and then analysed.

Results

Two major themes emerged from the analysis of interviews: compromise and feeling valued. The experience of returning to work was a process of compromise in which women found strategies to cope with their changing roles and demands, to find a balance between home and work life. The women wanted to feel valued by their managers and co‐workers, as this enabled them to feel comfortable and confident with some of the compromises they made.

Conclusion

Occupational therapists returning to work after maternity leave will make compromises so that they can balance their home and work life. Occupational therapists value managers and co‐workers who understand the compromises women make when returning to work following maternity leave and who create a supportive workplace that acknowledges and values their contribution.
Predictors of time to complete toileting for children with spina bifida
Authors: Gribble Nigel , Parsons Richard , Donlau Marie , Falkmer Torbjorn
Published: June 2013

Background/aim

Previous research has shown that children with spina bifida use clean intermittent catheterisation for urination, a rather complex procedure that increases the time taken to completion. However, no studies have analysed the factors impacting on the time taken to complete the urination that could inform occupational therapy practice. Therefore, the aim was to identify the variables that predict extended time children with spina bifida take to complete urination.

Methods

Fifty children, aged 5–18 years old with spina bifida using clean intermittent catheterisation, were observed while toileting and responding to a set of assessments tools, among them the Canadian Occupational Performance Measure. A logistic regression was used to identify which variables were independently associated with an extended toileting time.

Results

Children with spina bifida do take long time to urinate. More than half of this study's participants required more than five minutes completing urination, but not all required extended times. Ambulant, independent girls were more likely to perform toileting in less than six minutes compared with other children with spina bifida. However, age, IQ, maintained focus on the task, Canadian Occupational Performance Measure, time processing abilities and self‐reported ratings of independence appeared to be of no relevance, to predict extended toileting times.

Conclusion

To minimise occupational disruption caused by extended toileting times, occupational therapists should utilise the relevant predictors: gender, independence and ambulation when they prioritise children for relevant interventions.
Application of the Human Activity Assistive Technology model for occupational therapy research
Authors: Giesbrecht Ed
Published: June 2013

Background/aim

Theoretical models provide a framework for describing practice and integrating evidence into systematic research. There are few models that relate specifically to the provision of assistive technology in occupational therapy practice. The Human Activity Assistive Technology model is an enduring example that has continued to develop by integrating a social model of disability, concepts from occupational therapy theory and principles of assistive technology adoption and abandonment.

Methods

This study first describes the core concepts of the Human Activity Assistive Technology model and reviews its development over three successive published versions. A review of the research literature reflects application of the model to clinical practice, study design, outcome measure selection and interpretation of results, particularly among occupational therapists. An evaluative framework is used to critique the adequacy of the Human Activity Assistive Technology model for practice and research, exploring attributes of clarity, simplicity, generality, accessibility and importance. Finally, recommendations are proposed for continued development of the model and research applications.

Results

Most of the existing research literature employs the Human Activity Assistive Technology model for background and study design; there is emerging evidence to support the core concepts as predictive factors. Although the concepts are generally simple, clear and applicable to occupational therapy practice and research, evolving terminology and outcomes become more complex with the conflation of integrated theories.

Conclusions and significance

The development of the Human Activity Assistive Technology model offers enhanced access and application for occupational therapists, but poses challenges to clarity among concepts. Suggestions are made for further development and applications of the model.
Icariin attenuates high glucose‐induced type IV collagen and fibronectin accumulation in glomerular mesangial cells by inhibiting transforming growth factor‐β production and signalling through G protein‐coupled oestrogen receptor 1
Authors: Li Yi‐Chen , Ding Xuan‐Sheng , Li Hui‐Mei , Zhang Cheng
Published: June 2013

Icariin has been shown to attenuate diabetic nephropathy in rats by decreasing transforming growth factor‐β (TGF‐β) and type IV collagen expression, but its mode of action in glomerular mesangial cells is uncertain. The present study aimed to investigate the effect of icariin on excess mesangial type IV collagen and fibronectin accumulation induced by high glucose, and to determine the mechanism underlying its protective effects.

Under high‐glucose conditions, icariin diminished type IV collagen and fibronectin accumulation, as well as TGF‐β production in human and rat mesangial cells. Mesangial cells treated with icariin after TGF‐β1 exposure expressed less type IV collagen and fibronectin than those without icariin treatment, suggesting inhibition by icariin of TGF‐β1 downstream pathways.

On TGF‐β1 stimulation, icariin inhibited TGF‐β canonical Smad signalling and extracellular signal‐regulated kinase (ERK)1/2 signalling by decreasing Smad2/3 and ERK1/2 phosphorylation in a dose‐dependent manner. U0126, which blocked the ERK1/2 pathway, exerted an additive effect on the icariin suppression of type IV collagen and fibronectin expression, enhancing the beneficial effects of icariin.

The G protein‐coupled oestrogen receptor 1 (GPER) antagonist, G‐15, abolished the icariin‐induced inhibition of type IV collagen, and fibronectin overproduction and TGF‐β signalling. Treatment of cells with fulvestrant, a downregulator of the oestrogen receptor, enhanced the action of icariin.

In conclusion, icariin decreased type IV collagen and fibronectin accumulation induced by high glucose in mesangial cells by inhibiting TGF‐β production, as well as Smad and ERK signalling in a GPER‐dependent manner.
The Effects of Cross‐border and Cross‐industry Mergers and Acquisitions on Home‐region and Global Multinational Enterprises
Authors: Kling Gerhard , Ghobadian Abby , Hitt Michael A. , Weitzel Utz , O'Regan Nicholas
Published: June 2013

We examine the effects of international and product diversification through mergers and acquisitions (M&As) on the firm's risk–return profile. We identify the rewards from different types of M&As and investigate whether becoming a global firm is a value‐enhancing strategy. Drawing on the theoretical work of Vachani (Journal of International Business Studies, 22 (1991), pp. 307−222) and on Rugman and Verbeke's (Journal of International Business Studies, 35 (2004), pp. 3−18) metrics, we classify firms according to their degree of international and product diversification. To account for the endogeneity of M&As, we develop a panel vector autoregression. We find that global and host‐region multinational enterprises benefit from cross‐border M&As that reinforce their geographical footprint. Cross‐industry M&As enhance the risk–return profile of home‐region firms. This effect depends on the degree of product diversification. Hence there is no value‐enhancing M&A strategy for home‐region and bi‐regional firms to become ‘truly global’.
The Complexities of a New Faith: Xu Guangqi's Acceptance of Christianity
Authors: Liu Yu
Published: June 2013

Xu Guangqi (1562–1633) was one of the most important early Chinese Catholics closely associated with Matteo Ricci (1552–1610), the legendary founder of the Jesuit China mission. In spite of his widespread fame since the seventeenth century, the precise nature of his religious experience has not so far been adequately investigated. To understand his complex relationship with Christianity and thereby gain insight into the fateful East–West intellectual interaction in the early modern period, this article closely probes various aspects of Xu's spiritual journey including his family history, his reception of baptism, and his association with Jesuit missionaries both before and after his conversion, and the particular character of his Catholic faith.
A dual‐acidification process for the manufacture of direct‐acidified Cottage cheese
Authors: Makhal Subarna , Kanawjia Suresh K , Giri Apurba
Published: June 2013

A technology is described for manufacturing Cottage cheese which involved initial cold (4 °C) acidification of milk with HCl to bring down the pH to 5.3 followed by tempering slowly to 15 °C and subsequent acidification through slow hydrolysis of glucono delta lactone, resulting in a drop in pH to 5.0 and thereafter renneting at 20 °C followed by setting and cutting of curd and subsequent cooking at 35 °C for ~30 min. The method enabled manufacturing of Cottage cheese curd with average moisture, curd yield and curd hardness being 74.30%, 11.88% and 648.30 mN, respectively.
δ18O of Ethanol in Wine and Spirits for Authentication Purposes
Authors: Perini Matteo , Camin Federica
Published: June 2013

Since 1986 the European Union has established official isotopic analysis methods for detecting the illegal addition of sugar and water to wine and to enable geographical traceability. In this paper we investigate the possibility of using analysis of the 18O/16O stable isotope ratio (expressed as δ18O) of ethanol to improve detection of the watering of wine and to determine the origin of ethanol. Sixty‐nine authentic wine samples from all over Italy, 59 spirits from fruit and cereals, 5 chemically synthesized ethanols, one concentrated and rectified must, one beet and one cane sugar, one fresh must, and 6 waters with increasing δ18O values were considered. Ethanol was recovered by distillation, using a Cadiot spinning band column, following the official OIV methods. The residual water was trapped by storing the distillate for at least 24 h on a molecular sieve. The 18O/16O ratio was measured using a pyrolyser interfaced with an isotope ratio mass spectrometer. The δ‐18O of ethanol is significantly related to the δ18O of the fermentation water and can be considered as a reliable internal reference. The values ranged from +24‰ to +36‰ in wine (years 2008 to 2012), +10‰ to +26‰ in fruit and cereal distillates, and from –2‰ to +12‰ in synthetic ethanol. The method was shown to be effective in improving detection of the watering of wine and determining the origin of ethanol (from grapes, other fruit, or synthesis), but not in detecting the addition of cane or beet sugar to wine.
Quality Assessment of Commercially Processed Carbon Monoxide‐Treated Tilapia Fillets
Authors: Pivarnik Lori F. , Faustman Cameron , Suman Surendranath P. , Palmer Catherine , Richard Nicole L. , Ellis P. Christopher , DiLiberti Michael
Published: June 2013

Carbon monoxide (CO) has been used to stabilize the color of fish muscle during frozen storage and distribution. This study compared changes in the quality profiles of CO‐treated and untreated (UT) tilapia fillets stored at 21 to 22 °C (room temperature), 4 to 5 °C (refrigerated), and 0 °C (iced). Samples (n = 3) were analyzed at different time intervals for chemical, lipid oxidation, microbiological, color, and expert sensory profiles. CO samples contained greater (P < 0.05) apparent ammonia and total volatile base nitrogen (TVB‐N) at day 0, with greater (P < 0.05) TVB‐N throughout refrigerated and iced storage. At time 0, peroxide values (POV) and thiobarbituric‐acid‐reactive substances were lower (P < 0.05) for CO samples and continued to have lower trends throughout all storage temperatures. Microbiological analysis at time 0 did not show any differences between UT and CO samples. Redness (a*) color values were greater (P < 0.05) in CO tilapia at time 0; however, treated product showed a more rapid decline in a* throughout all storage temperatures. While expert sensory evaluation showed no statistical differences between UT and CO tilapia at time 0, CO product failed sensory assessment sooner than UT product when stored refrigerated and in ice.
Experimental diabetes‐induced testicular damage in prepubertal rats (在青春期前大鼠中实验性糖尿病导致的睾丸损伤)
Authors: Kyathanahalli Chandrashekara , Bangalore Srinag , Hanumanthappa Krishnamurthy , Muralidhara
Published: June 2013

Background

There has been a marked increase in the prevalence of childhood and/or adolescent diabetes worldwide. Testicular dysfunction in adult‐onset diabetes is well established, whereas the impact of early onset diabetes on the functional development of the testis remains elusive. In the present study we investigated early oxidative impairments and progressive histological changes in streptozotocin (STZ)‐induced diabetic prepubertal rat testis.

Methods

Testes were sampled from prepubertal rats injected with a single bolus of STZ (90 mg/kg, i.p.) on Days 1, 3, 5, 7 and 14 after STZ injection for quantitation of testicular oxidative stress parameters in isolated subcellular fractions and mitochondrial and microsomal functional efficiency, as well as at weekly intervals over a period of 8 weeks for histological and flow cytometry analyses.

Results

Prepubertal diabetic rats were severely hyperglycemic with reduced testes size. At the subcellular level, a progressive increase in oxidative stress parameters was discernible in the cytosolic and microsomal compartments from Day 1 after STZ, together with decreased antioxidant defenses. Surprisingly, tissue ascorbate and free catalytic iron levels were notably increased in diabetic rat testis. Mitochondrial dysfunction was manifested from Day 5, as evidenced by a reduction in electron transport activity. Histologically, tissue sections showed distorted seminiferous tubules and extensive cell vacuolization with progressive disappearance of spermatids in the lumen by Week 7 after STZ injection, observations that were consistent with flow cytometry data.

Conclusions

Herein we provide evidence that the onset of diabetes brings about oxidative changes at the subcellular level that cumulatively affect the functional growth of testes.