bluuebunny/crossref_metadata_2025 huggingface dataset:
Note: Electrode polarization of Galinstan electrodes for liquid impedance spectroscopy
Authors: Mellor Brett L. , Kellis Nathan A. , Mazzeo Brian A.
Published: April 2011

Electrode polarization is a significant obstacle in the impedance measurements of ionic liquids. An atomically smooth electrode surface could potentially reduce unwanted impedance contributions from electrode polarization. Liquid metal electrodes were formed by adhering Galinstan to acrylic plates in a parallel-plate capacitor arrangement. Electrode polarization was compared to a similar cell with stainless steel electrodes. The impedance of salt and protein solutions (β-lactoglobulin) was measured from 40 Hz to 110 MHz. Because of oxide layer formation, the performance of the Galinstan electrode is significantly different than the theoretical ideal.
The Choi–Jamiolkowski forms of quantum Gaussian channels
Authors: Holevo A. S.
Published: April 2011

We obtain explicit expressions for the Choi–Jamiolkowski (CJ) forms and operators defining a general bosonic Gaussian channel. The four principal cases are considered in Sec. III; in Sec. IV, we give a decomposition of Gaussian CJ form into product of these four principal types and provide a necessary and sufficient condition for the existence of the bounded CJ operator.
Low voltage electron diffractive imaging of atomic structure in single-wall carbon nanotubes
Authors: Kamimura Osamu , Maehara Yosuke , Dobashi Takashi , Kobayashi Keita , Kitaura Ryo , Shinohara Hisanori , Shioya Hiroyuki , Gohara Kazutoshi
Published: April 2011

The demand for atomic-scale analysis without serious damage to the specimen has been increasing due to the spread of applications with light-element three-dimensional (3D) materials. Low voltage electron diffractive imaging has the potential possibility to clarify the atomic-scale structure of 3D materials without causing serious damage to specimens. We demonstrate low-voltage (30 kV) electron diffractive imaging of single-wall carbon nanotube at a resolution of 0.12 nm. In the reconstructed pattern, the intensity difference between single carbon atom and two overlapping atoms can be clearly distinguished. The present method can generally be applied to other materials including biologically important ones.
Effects of interwall interaction on the electrical conductance at the junction between a double-walled carbon nanotube and copper electrodes
Authors: Gao Feng , Qu Jianmin , Yao Matthew
Published: April 2011

Considered in this letter are the effects of interwall interaction on the electrical conductance at the junction of a double-walled carbon nanotube (DWCNT) between two copper electrodes. In the end-contact configuration, the effect of interwall interaction on the electrical conductance is rather weak, and both walls of DWCNT contribute to the electronic transport almost as if they are parallel connectors. In the side-contact configuration, not only the inner tube does not contribute to the overall electrical conductance, its presence hinders the electronic transport of the outer wall by causing significant localization of density of states near the Fermi level.
Ferrimagnetic stripe domain formation in antiferromagnetically-coupled Co/Pt–Co/Ni–Co/Pt multilayers studied via soft x-ray techniques
Authors: Hellwig O. , Günther C. M. , Radu F. , Menzel A. , Schlotter W. F. , Lüning J. , Eisebitt S.
Published: April 2011

We investigate the macroscopic and microscopic magnetic reversal in perpendicular anisotropy antiferromagnetically (AF) coupled [Co/Pt]N−1/Co–Ru–[Co/Ni]M−1/Co–Ru–[Co/Pt]N−1/Co multilayers (ML) using soft x-ray spectroholography and local, as well as area-integrated, soft x-ray hysteresis loop techniques. For N=25⪢M=3 we find ferrimagnetic stripe domains in remanence due to the combination of strong dipolar fields from the thick Co/Pt MLs with a strong AF-interlayer exchange coupling of the thin Co/Ni ML in the center, which reverses its polarity three times during a magnetic field reversal. Furthermore, local hysteresis loops reveal distinct random spin-flip avalanches, thus indicating the existence of local magnetic pinning sites due to the insertion of the center Co/Ni stack.
Electronic and structural properties of the oxygen vacancy in BaTiO3
Authors: Choi Minseok , Oba Fumiyasu , Tanaka Isao
Published: April 2011

The electronic and structural properties of the oxygen vacancy (VO) in cubic BaTiO3 are studied using first-principles calculations based on a hybrid Hartree–Fock density functional approach. Our calculations identify the double shallow donor behavior of VO, indicating its contribution to the n-type conductivity. In addition, a metastable configuration is found, which shows an off-symmetric atomic structure around VO in conjunction with deep localized electronic states in the band gap. Based on the identified characteristics of VO, the previous experimental and theoretical findings are explained.
Structured scintillator for hard x-ray grating interferometry
Authors: Rutishauser Simon , Zanette Irene , Donath Tilman , Sahlholm Anna , Linnros Jan , David Christian
Published: April 2011

Grating interferometry at conventional x-ray tubes improves the quality of radiographies and tomograms by providing phase and scattering contrast data. The main challenge encountered when applying this technique at high photon energies, as required by many applications to obtain sufficient penetration depth, is to maintain a high fringe visibility. In this letter, we report on a substantial improvement in fringe visibility and according improvements in image quality achieved by replacing the absorbing analyzer grating of the interferometer with a structured scintillator grating. This development represents a significant step toward the implementation of this technique in industrial testing and medical applications.
Detailed balance limit of the efficiency of multilevel intermediate band solar cells
Authors: Nozawa Tomohiro , Arakawa Yasuhiko
Published: April 2011

Intermediate-band solar cells (IBSCs) promise ultrahigh solar-electricity energy conversion. We have calculated the detailed balance limit of the efficiency for IBSCs with multiple intermediate bands by optimizing IB’s energy levels. The results indicate that thermodynamic limit of IBSCs with 4 IBs is 74.6% which far exceeds 63% calculated in a previous study for the single IB case. By further increasing the total number IBs, the thermodynamic limit of IBSCs can ultimately approach nearly 80%.
Crystallized HfLaO embedded tetragonal ZrO2 for dynamic random access memory capacitor dielectrics
Authors: Shin Yunsang , Min Kyung Kyu , Lee Seok-Hee , Lim Sung Kyu , Oh Jae Sub , Lee Kee-Jeung , Hong Kwon , Cho Byung Jin
Published: April 2011

Cubic-structured HfLaO embedded tetragonal ZrO2 is investigated for application to a dynamic random access memory capacitor dielectric. It is found that hole injection is the determining factor of the leakage current in the ZrO2–HfLaO stack and thus HfLaO should be kept away from the electrode interface due to its smaller valance band offset than that of ZrO2. The insertion of cubic-structured HfLaO into tetragonal ZrO2 with an optimized thickness combination can effectively reduce the equivalent oxide thickness without increasing the leakage current.
23 GHz ferroelectric electron gun based gyrotron
Authors: Ben-Moshe R. , Einat M.
Published: April 2011

Ferroelectric cathodes have been explored as an alternative electron source for microwave tubes. Past experiments have demonstrated operation at frequencies of 2–10 GHz. Since the ferroelectric cathode is based on surface plasma, the relatively high energy spread limits the tube operation frequency. Hence, the possibility to obtain higher frequencies remained questionable. In this experimental work a gyrotron oscillator was designed with the operation frequency increased toward that of millimeter waves. A cylindrical tube with a cutoff frequency of ∼22 GHz was integrated to a ferroelectric electron gun. Pulses of ∼0.5 μs duration with a frequency of 23 GHz were obtained.
Dynamic programming procedure for searching optimal models to estimate substitution rates based on the maximum-likelihood method
Authors: Zhang Chengjun , Wang Jia , Xie Weibo , Zhou Gang , Long Manyuan , Zhang Qifa
Published: April 2011

The substitution rate in a gene can provide valuable information for understanding its functionality and evolution. A widely used method to estimate substitution rates is the maximum-likelihood method implemented in the CODEML program in the PAML package. A limited number of branch models, chosen based on a priori information or an interest in a particular lineage(s), are tested, whereas a large number of potential models are neglected. A complementary approach is also needed to test all or a large number of possible models to search for the globally optional model(s) of maximum likelihood. However, the computational time for this search even in a small number of sequences becomes impractically long. Thus, it is desirable to explore the most probable spaces to search for the optimal models. Using dynamic programming techniques, we developed a simple computational method for searching the most probable optimal branch-specific models in a practically feasible computational time. We propose three search methods to find the optimal models, which explored O(n) (method 1) to O(n
2
) (method 2 and method 3) models when the given phylogeny has
n
branches. In addition, we derived a formula to calculate the number of all possible models, revealing the complexity of finding the optimal branch-specific model. We show that in a reanalysis of over 50 previously published studies, the vast majority obtained better models with significantly higher likelihoods than the conventional hypothesis model methods.
Switching processes in financial markets
Authors: Preis Tobias , Schneider Johannes J. , Stanley H. Eugene
Published: April 2011

For an intriguing variety of switching processes in nature, the underlying complex system abruptly changes from one state to another in a highly discontinuous fashion. Financial market fluctuations are characterized by many abrupt switchings creating upward trends and downward trends, on time scales ranging from macroscopic trends persisting for hundreds of days to microscopic trends persisting for a few minutes. The question arises whether these ubiquitous switching processes have quantifiable features independent of the time horizon studied. We find striking scale-free behavior of the transaction volume after each switching. Our findings can be interpreted as being consistent with time-dependent collective behavior of financial market participants. We test the possible universality of our result by performing a parallel analysis of fluctuations in time intervals between transactions. We suggest that the well known catastrophic bubbles that occur on large time scales—such as the most recent financial crisis—may not be outliers but single dramatic representatives caused by the formation of increasing and decreasing trends on time scales varying over nine orders of magnitude from very large down to very small.
Redox potentials of primary electron acceptor quinone molecule (Q
A
)
−
and conserved energetics of photosystem II in cyanobacteria with chlorophyll
a
and chlorophyll
d
Authors: Allakhverdiev Suleyman I. , Tsuchiya Tohru , Watabe Kazuyuki , Kojima Akane , Los Dmitry A. , Tomo Tatsuya , Klimov Vyacheslav V. , Mimuro Mamoru
Published: April 2011

In a previous study, we measured the redox potential of the primary electron acceptor pheophytin (Phe)
a
of photosystem (PS) II in the chlorophyll
d
–dominated cyanobacterium
Acaryochloris marina
and a chlorophyll
a
–containing cyanobacterium,
Synechocystis
. We obtained the midpoint redox potential (
E
m
) values of −478 mV for
A. marina
and −536 mV for
Synechocystis
. In this study, we measured the redox potentials of the primary electron acceptor quinone molecule (Q
A
), i.e.,
E
m
(Q
A
/Q
A
−
), of PS II and the energy difference between [P680·Phe
a
−
·Q
A
] and [P680·Phe
a
·Q
A
−
], i.e., Δ
G
PhQ
. The
E
m
(Q
A
/Q
A
−
) of
A. marina
was determined to be +64 mV without the Mn cluster and was estimated to be −66 to −86 mV with a Mn-depletion shift (130–150 mV), as observed with other organisms. The
E
m
(Phe
a
/Phe
a
−
) in
Synechocystis
was measured to be −525 mV with the Mn cluster, which is consistent with our previous report. The Mn-depleted downshift of the potential was measured to be approximately −77 mV in
Synechocystis
, and this value was applied to
A. marina
(−478 mV); the
E
m
(Phe
a
/Phe
a
−
) was estimated to be approximately −401 mV. These values gave rise to a Δ
G
PhQ
of −325 mV for
A. marina
and −383 mV for
Synechocystis
. In the two cyanobacteria, the energetics in PS II were conserved, even though the potentials of Q
A
−
and Phe
a
−
were relatively shifted depending on the special pair, indicating a common strategy for electron transfer in oxygenic photosynthetic organisms.
Repurposing lipoic acid changes electron flow in two important metabolic pathways of
Escherichia coli
Authors: Feeney Morgan Anne , Veeravalli Karthik , Boyd Dana , Gon Stéphanie , Faulkner Melinda Jo , Georgiou George , Beckwith Jonathan
Published: April 2011

In bacteria, cysteines of cytoplasmic proteins, including the essential enzyme ribonucleotide reductase (RNR), are maintained in the reduced state by the thioredoxin and glutathione/glutaredoxin pathways. An
Escherichia coli
mutant lacking both glutathione reductase and thioredoxin reductase cannot grow because RNR is disulfide bonded and nonfunctional. Here we report that suppressor mutations in the
lpdA
gene, which encodes the oxidative enzyme lipoamide dehydrogenase required for tricarboxylic acid (TCA) cycle functioning, restore growth to this redox-defective mutant. The suppressor mutations reduce LpdA activity, causing the accumulation of dihydrolipoamide, the reduced protein-bound form of lipoic acid. Dihydrolipoamide can then provide electrons for the reactivation of RNR through reduction of glutaredoxins. Dihydrolipoamide is oxidized in the process, restoring function to the TCA cycle. Thus, two electron transfer pathways are rewired to meet both oxidative and reductive needs of the cell: dihydrolipoamide functionally replaces glutathione, and the glutaredoxins replace LpdA. Both lipoic acid and glutaredoxins act in the reverse manner from their normal cellular functions. Bioinformatic analysis suggests that such activities may also function in other bacteria.
Infinite multiplicity for an inhomogeneous supercritical problem in entire space
Authors: Lai Baishun , Ge Zhihao
Published: April 2011

In this paper, we will prove the existence of infinitely many positive solutions to the following supercritical problem by using the Liapunov-Schmidt reduction method and asymptotic analysis:
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartLayout 1st Row StartLayout Enlarged left-brace 1st Row normal upper Delta u plus u Superscript p Baseline plus f left-parenthesis x right-parenthesis equals 0 comma u greater-than 0 in double-struck upper R Superscript n Baseline comma 2nd Row limit Underscript StartAbsoluteValue x EndAbsoluteValue right-arrow normal infinity Endscripts u left-parenthesis x right-parenthesis right-arrow 0 period EndLayout EndLayout">

{

Δ
u
+

u

p

+
f
(
x
)
=
0
,
 
 
u
>
0
 
 

in

 

R

n

,

lim

|

x

|

→
∞

u
(
x
)
→
0.

\begin{eqnarray*} \left \{ \begin {array}{ll} \Delta u + u^{p}+f(x)=0,\ \ u>0\ \ \mbox {in}\ \mathbb {R}^{n},\\ \lim _{|x|\to \infty }u(x)\to 0. \end{array} \right . \end{eqnarray*}
Long-distance migrating species of birds travel in larger groups
Authors: Beauchamp Guy
Published: April 2011

How individuals migrate over long distances is an enduring mystery of animal migration. Strong selection pressure for travelling in groups has been suggested in long-distance migrating species. Travelling in groups can reduce the energetic demands of long migration, increase navigational accuracy and favour group foraging at migratory halts. Nevertheless, this hypothesis has received scant attention. I examined evolutionary transitions in migration distance in all North American breeding species of birds. I documented 72 evolutionary shifts in migration distance in the pool of 409 species. In contrasting clades, long-distance migration, as opposed to short-distance migration, was associated with a larger travelling group size. No other transitions occurred alongside in other traits such as group size in the non-breeding season or body mass. The results suggest that larger group sizes have been beneficial in the evolution of long-distance migration in a large clade of birds.
Female but not male dogs respond to a size constancy violation
Authors: Müller Corsin A. , Mayer Christina , Dörrenberg Sebastian , Huber Ludwig , Range Friederike
Published: April 2011

Differences between sexes in cognitive processes are widespread in humans and permeate many, if not most, cognitive domains. In animal cognition research, however, possible sex differences are still often neglected. Here, we provide striking evidence for a sex-specific response in an object permanence task in domestic dogs (
Canis familiaris
). Female dogs responded with significantly increased looking times to a violation of expectancy—a ball ‘magically’ changing size while temporarily occluded. By contrast, male dogs, irrespective of their neuter status, did not respond to the size constancy violation. These results indicate that sex differences in basic cognitive processes may extend to mammals in general, and call for increased consideration of possible sex effects when analysing and interpreting data in animal cognition.
Fit to print? Referee reports on mathematics for the nineteenth-century journals of the Royal Society of London
Authors: Despeaux Sloan Evans
Published: April 2011

The Royal Society was one of the first British scientific societies to establish a peer review process for papers submitted to its journals. Initially, its peer review procedures were at best informal, but by the 1830s they became a formal, required gateway for all Royal Society submissions. This paper focuses on referee reports of mathematical papers submitted to the Society from 1832 to 1900, years covered in the first 15 volumes of referee reports archived at the Royal Society Library. Besides judging the content of papers, mathematical referees during this period discussed issues of professionalization and politics in their reports.
Canards and curvature: the ‘smallness of

ε

’ in slow–fast dynamics
Authors: Desroches Mathieu , Jeffrey Mike R.
Published: April 2011

A criterion for the existence of canards in singularly perturbed dynamical systems is presented. Canards are counterintuitive solutions that evolve along both attracting and repelling branches of invariant manifolds. In two dimensions, canards result in periodic oscillations whose amplitude and period grow in a highly nonlinear way: they are slowly varying with respect to a control parameter, except for an exponentially small range of values where they grow extremely rapidly. This sudden growth, called a
canard explosion
, has been encountered in many applications ranging from chemistry to neuronal dynamics, aerospace engineering and ecology. Here, we give quantitative meaning to the frequently encountered statement that the singular perturbation parameter
ε
, which represents a ratio between fast and slow time scales, is ‘small enough’ for canards to exist. If limit cycles exist, then the criterion expresses the condition that
ε
must be small enough for there to exist a set of zero-curvature in the neighbourhood of a repelling slow manifold, where orbits can develop inflection points, and thus form the non-convex cycles observed in a canard explosion. We apply the criterion to examples in two and three dimensions, namely to supercritical and subcritical forms of the van der Pol oscillator, and a prototypical three time-scale system with slow passage through a canard explosion.
Association studies for next-generation sequencing
Authors: Luo Li , Boerwinkle Eric , Xiong Momiao
Published: April 2011

Genome-wide association studies (GWAS) have become the primary approach for identifying genes with common variants influencing complex diseases. Despite considerable progress, the common variations identified by GWAS account for only a small fraction of disease heritability and are unlikely to explain the majority of phenotypic variations of common diseases. A potential source of the missing heritability is the contribution of rare variants. Next-generation sequencing technologies will detect millions of novel rare variants, but these technologies have three defining features: identification of a large number of rare variants, a high proportion of sequence errors, and a large proportion of missing data. These features raise challenges for testing the association of rare variants with phenotypes of interest. In this study, we use a genome continuum model and functional principal components as a general principle for developing novel and powerful association analysis methods designed for resequencing data. We use simulations to calculate the type I error rates and the power of nine alternative statistics: two functional principal component analysis (FPCA)–based statistics, the multivariate principal component analysis (MPCA)–based statistic, the weighted sum (WSS), the variable-threshold (VT) method, the generalized T2, the collapsing method, the CMC method, and individual tests. We also examined the impact of sequence errors on their type I error rates. Finally, we apply the nine statistics to the published resequencing data set from ANGPTL4 in the Dallas Heart Study. We report that FPCA-based statistics have a higher power to detect association of rare variants and a stronger ability to filter sequence errors than the other seven methods.
DNA methylation profiling reveals novel biomarkers and important roles for DNA methyltransferases in prostate cancer
Authors: Kobayashi Yuya , Absher Devin M. , Gulzar Zulfiqar G. , Young Sarah R. , McKenney Jesse K. , Peehl Donna M. , Brooks James D. , Myers Richard M. , Sherlock Gavin
Published: April 2011

Candidate gene-based studies have identified a handful of aberrant CpG DNA methylation events in prostate cancer. However, DNA methylation profiles have not been compared on a large scale between prostate tumor and normal prostate, and the mechanisms behind these alterations are unknown. In this study, we quantitatively profiled 95 primary prostate tumors and 86 benign adjacent prostate tissue samples for their DNA methylation levels at 26,333 CpGs representing 14,104 gene promoters by using the Illumina HumanMethylation27 platform. A 2-class Significance Analysis of this data set revealed 5912 CpG sites with increased DNA methylation and 2151 CpG sites with decreased DNA methylation in tumors (FDR < 0.8%). Prediction Analysis of this data set identified 87 CpGs that are the most predictive diagnostic methylation biomarkers of prostate cancer. By integrating available clinical follow-up data, we also identified 69 prognostic DNA methylation alterations that correlate with biochemical recurrence of the tumor. To identify the mechanisms responsible for these genome-wide DNA methylation alterations, we measured the gene expression levels of several DNA methyltransferases (DNMTs) and their interacting proteins by TaqMan qPCR and observed increased expression ofDNMT3A2,DNMT3B, andEZH2in tumors. Subsequent transient transfection assays in cultured primary prostate cells revealed thatDNMT3B1andDNMT3B2overexpression resulted in increased methylation of a substantial subset of CpG sites that showed tumor-specific increased methylation.
Longitudinal attentional engagement rescues mice from age-related cognitive declines and cognitive inflexibility
Authors: Matzel Louis D. , Light Kenneth R. , Wass Christopher , Colas-Zelin Danielle , Denman-Brice Alexander , Waddel Adam C. , Kolata Stefan
Published: April 2011

Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement.
A Conserved, Mg2+-Dependent Exonuclease Degrades Organelle DNA duringArabidopsisPollen Development
Authors: Matsushima Ryo , Tang Lay Yin , Zhang Lingang , Yamada Hiroshi , Twell David , Sakamoto Wataru
Published: April 2011

In plant cells, mitochondria and plastids contain their own genomes derived from the ancestral bacteria endosymbiont. Despite their limited genetic capacity, these multicopy organelle genomes account for a substantial fraction of total cellular DNA, raising the question of whether organelle DNA quantity is controlled spatially or temporally. In this study, we genetically dissected the organelle DNA decrease in pollen, a phenomenon that appears to be common in most angiosperm species. By staining mature pollen grains with fluorescent DNA dye, we screened Arabidopsis thaliana for mutants in which extrachromosomal DNAs had accumulated. Such a recessive mutant, termed defective in pollen organelle DNA degradation1 (dpd1), showing elevated levels of DNAs in both plastids and mitochondria, was isolated and characterized. DPD1 encodes a protein belonging to the exonuclease family, whose homologs appear to be found in angiosperms. Indeed, DPD1 has Mg2+-dependent exonuclease activity when expressed as a fusion protein and when assayed in vitro and is highly active in developing pollen. Consistent with the dpd phenotype, DPD1 is dual-targeted to plastids and mitochondria. Therefore, we provide evidence of active organelle DNA degradation in the angiosperm male gametophyte, primarily independent of maternal inheritance; the biological function of organellar DNA degradation in pollen is currently unclear.
Comparison of catechins and volatile compounds among different types of tea using high performance liquid chromatograph and gas chromatograph mass spectrometer
Authors: Wang Kunbo , Liu Fang , Liu Zhonghua , Huang Jianan , Xu Zhongxi , Li Yinhua , Chen Jinhua , Gong Yushun , Yang Xinghe
Published: April 2011

As tea is one of the most popular beverages consumed worldwide, it is important for customers and business investigators to develop an easy and reliable method to discriminate between different types of teas from each other. A total of eighty‐seven types of various white, green, oolong, black and Puer teas were collected from the major tea estates in China, and their catechin contents and volatile compounds were compared by high performance liquid chromatograph and gas chromatograph mass spectrometer. It was found green tea contained the highest concentrations of total catechins, (−)‐epicatechin gallate (ECG) and (−)‐epigallocatechin gallate (EGCG), while oolong teas contained the highest concentrations of (−)‐epigallocatechin (EGC) among these five types of teas. The aroma composition and their quantities in different types of teas varied quite widely. The concentration of ECG, EGCG, pentanal, hexanal, methyl jasmonate, indole, (E,E)‐2,4‐hexadienal and 1,2,3‐trimethoxybenzene was shown to be different and could be used to discriminate white, green, oolong, black and Puer teas. The result showed that different types of teas could be partially classified by cluster analysis using index of individual catechins and volatile components.
Lipid and protein stability of partially defatted walnut flour (Juglans regiaL.) during storage
Authors: Labuckas Diana , Maestri Damián , Lamarque Alicia
Published: April 2011

Partially defatted walnut flour (WF) was stored (25 °C, 800 Lux) for an 8‐month period and evaluated monthly in some protein properties and oil oxidative parameters. Transparent plastic‐laminated (WFPL) and plastic‐laminated, aluminium‐coated (WFAC) packages were used. During the first 3 months, samples were more susceptible to endogenous hydrolysis; an increase in soluble peptide concentration was determined for both WFAC and WFPL. Minor changes between WFAC and WFPL were observed in protein electrophoretic patterns along storage period, but no differences were determined in total protein solubility. However, a progressive reduction in water‐holding capacity (47% from time 0 to month 8) was observed for WFPL. A major effect of packaging material was found on lipid‐quality parameters. Packaging materials’ barrier to light effectively protect WF against polyunsaturated FA degradation and oil oxidation. Lipids from WF stored in plastic‐laminated packages showed decreasing double‐bond index values (from 1.71 at initial time, to 1.45 after 6 months of storage) and increasing oxidation rates along storage test. Aluminium‐coated packages can be used to keep quality of WF for 8 months at room temperature.
Instrumental and sensory evaluation of cooked pasta during frozen storage
Authors: Olivera Daniela F. , Salvadori Viviana O.
Published: April 2011

Food consumption patterns have changed significantly during the last years, showing an increase in the consumption of convenience foods. Frozen foods represent an important segment of this market. The aim of the present paper was to study the influence of frozen storage on the quality of cooked organic tagliatelle. Instrumental measurements of different quality parameters (moisture content, colour, textural and rheological characteristics of frozen cooked pasta) were performed during twelve months of storage. The sensory properties of pasta were also evaluated by means of an acceptability study. In general, both instrumental and sensory analysis found that frozen storage affects negatively the acceptability of cooked pasta. The advantages obtained through fast freezing procedures are not maintained along storage, being hardness (instrumental) and consistency (sensory) the most relevant quality indices. Finally, the shelf life of the product was calculated as 3.6 and 3.8 months in the cryogenic device and air‐blast tunnel, respectively, based on simple kinetic models.
Concentration of n‐3 polyunsaturated fatty acids in cholesterol‐reduced cod‐liver oil by lipases
Authors: Lee Jung Eun , Chang Yoon Hyuk , Ganesan Palanivel , Kwak Hae‐Soo
Published: April 2011

This study was conducted to elucidate the effects of different lipases originated from Candida rugosa (CR), porcine pancreas (PP) and Aspergillus niger (AN) on the degree of hydrolysis (DH) in cholesterol‐reduced cod‐liver oil (87.5%) and evaluate the changes in n‐3 polyunsaturated fatty acid concentrations in the oil hydrolysed by the lipases. The lipase‐catalysed hydrolysis of cholesterol‐reduced cod‐liver oil was performed at 37 °C for 8 h. Among all the lipase samples studied, DH in the oil after lipase‐catalysed hydrolysis followed the decreasing order: CR lipase (70.01%) > PP lipase (26.18%) > AN lipase (18.57%). Triacylglycerol levels in the oil hydrolysed by all the lipases studied decreased, while mono‐ and diacylglycerol levels increased during lipase‐catalysed hydrolysis. The eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in cholesterol‐reduced cod‐liver oil hydrolysed by the CR lipase were remarkably higher than those by the PP or AN lipase. Thus, it is suggested in this study that the CR lipase appears to be most suitable for producing and n‐3 polyunsaturated fatty acids including EPA and DHA concentrates from cholesterol‐reduced cod‐liver oil.
Malnutrition and feeding difficulty in Taiwanese older with dementia
Authors: Chang Chia‐Chi , Roberts Beverly L
Published: April 2011

Aims and objectives.  To determine differences in the physical and psychological factors and feeding difficulty between people who are well‐nourished and malnourished and to determine the predictors of risk of malnutrition and malnutrition in Taiwanese residents with dementia.

Background.  Malnutrition is a common problem among nursing home residents but frequently is unrecognised. Nutritional status of older people is associated with cognitive impairment and patients with dementia have high risk for malnutrition because of difficulties in eating.

Design.  A cross‐sectional design was used to determine predictors of risk of malnutrition and malnutrition.

Methods.  Subjects were recruited from five Taiwanese long‐term care facilities. Data were collected using Mini Nutritional Assessment Screening Form, body mass index, Short Portable Mental Status Questionnaire, Barthel index, Edinburgh Feeding Evaluation in Dementia scale and eating time.

Results.  Eighty‐three subjects participated. According to the Mini Nutritional Assessment Screening Form cut‐point scores, 75 (90·4%) residents with dementia had risk of malnutrition. However, using the World Health Organization (WHO) body mass index cut‐point of <18·5, the prevalence rate of malnutrition was 19%. Using logistic regression, gender (odds ratio: 38·627, 95% CI: 1·927–774·407) and eating time (odds ratio: 0·814, 95% CI: 0·689–0·962) were significant predictors of risk of malnutrition. However, only gender (odds ratio: 6·12, 95% CI: 1·05–35·662) was a significant predictor of malnutrition using the WHO body mass index cut‐point.

Conclusions.  The prevalence of the risk for malnutrition was high in residents with dementia in Taiwanese nursing homes. Feeding difficulty, activities of daily living dependence, cognitive impairment, number of medications and age increased with malnutrition while shorter eating times were associated with poorer nutrition. However, when the factors were considered together, only being female and eating time were significant risk factors for malnutrition. Being female was the only significant factor of malnutrition.

Relevance to clinical practice.  Monthly monitoring of weight and assessment with Mini Nutritional Assessment Screening Form are essential to early identification of emerging malnutrition and implementation of interventions. Providing nutritional supplements and energy and protein‐dense food may be needed for good nutrition and more time for eating or feeding assistance may delay malnutrition or even improve nutritional status.
Effect of dexmedetomidine on the minimum alveolar concentration of isoflurane in cats
Authors: ESCOBAR A. , PYPENDOP B. H. , SIAO K. T. , STANLEY S. D. , ILKIW J. E.
Published: April 2011

Escobar, A., Pypendop, B. H., Siao, K. T., Stanley, S. D., Ilkiw, J. E. Effect of dexmedetomidine on the minimum alveolar concentration of isoflurane in cats.J. vet. Pharmacol. Therap. 35, 163–168.

This study reports the effects of dexmedetomidine on the minimum alveolar concentration of isoflurane (MACiso) in cats. Six healthy adult female cats were used. MACisoand dexmedetomidine pharmacokinetics had previously been determined in each individual. Cats were anesthetized with isoflurane in oxygen. Dexmedetomidine was administered intravenously using target‐controlled infusions to maintain plasma concentrations of 0.16, 0.31, 0.63, 1.25, 2.5, 5, 10, and 20 ng/mL. MACisowas determined in triplicate at each target plasma dexmedetomidine concentration. Blood samples were collected and analyzed for dexmedetomidine concentration. The following model was fitted to the concentration–effect data:imagewhere MACiso.cis MACisoat plasma dexmedetomidine concentration C, MACiso.0is MACisoin the absence of dexmedetomidine,Imaxis the maximum possible reduction in MACiso, and IC50is the plasma dexmedetomidine concentration producing 50% ofImax. Mean ± SE MACiso.0, determined in a previous study conducted under conditions identical to those in this study, was 2.07 ± 0.04. Weighted mean ± SEImax, and IC50estimated by the model were 1.76 ± 0.07%, and 1.05 ± 0.08 ng/mL, respectively. Dexmedetomidine decreased MACisoin a concentration‐dependent manner. The lowest MACisopredicted by the model was 0.38 ± 0.08%, illustrating that dexmedetomidine alone is not expected to result in immobility in response to noxious stimulation in cats at any plasma concentration.
Protection of calves against Haemonchus placei and Haemonchus contortus after immunization with gut membrane proteins from H. contortus
Authors: BASSETTO C. C. , SILVA B. F. , NEWLANDS G. F. J. , SMITH W. D. , AMARANTE A. F. T.
Published: April 2011

A vaccine containing integral membrane glycoproteins from the intestine of Haemonchus contortus was evaluated in four groups of nine worm‐free calves challenged with either 8000 H. contortus or Haemonchus placei infective larvae. Vaccinates received 50 μg of the antigen and 1 mg QuilA adjuvant three times 21 days apart, while the controls got adjuvant alone. The calves were challenged 7 days after the last immunization and killed for worm counts 43 days later. Immunization resulted in high titre antibodies against the vaccine antigens and significant reduction in egg output and worm numbers of both challenge species, compared with control calves. It was concluded that vaccination of calves with native parasite gut membrane glycoproteins obtained from H. contortus conferred protection against both H. placei and H. contortus.
Reliability and validity of the German version of the OPTION scale
Authors: Hirsch Oliver , Keller Heidemarie , Müller‐Engelmann Meike , Gutenbrunner Monika Heinzel , Krones Tanja , Donner‐Banzhoff Norbert
Published: April 2011

Objective To examine the psychometric properties of the German version of the ‘observing patient involvement’ scale (OPTION) by analysing video recordings of primary care consultations dealing with counselling in cardiovascular prevention.

Design Cross‐sectional assessment of physician–patient interaction by two rater pairs and two experts in shared decision making (SDM).

Setting Primary care.

Participants Fifteen general practitioners provided 40 videographed consultations.

Measurements Video ratings using the OPTION instrument.

Results Mean differences on item level between the four raters were quite large. Most items were skewed towards minimal levels of shared decision making. Measures of inter‐rater association showed low to moderate associations on item level and high associations on total score level. Cronbach‐α of the whole scale based on the data of all four raters is 0.90 and therefore on a high level. An oblique factor analysis revealed two factors, but both factors were highly correlated so we can confirm a one‐dimensional structure of the instrument. ROC analyses between the rater total scores and dichotomized expert ratings (SDM yes/no) revealed a good discriminability of the OPTION total score. Physicians with more expertise in shared decision making received higher OPTION ratings.

Conclusions The German version of the OPTION scale is reliable at total score level. Some items need further revision in the direction of more concrete, observable behaviour. We were only able to perform a quasi‐validation of the scale. Validity issues need further research efforts.
Identification of a novel HLA‐DRB1*04:94N allele by polymerase chain reaction sequence‐based typing
Authors: Zhu F.‐M. , Wang W. , Zhang W. , Lv H.‐J. , Yan L.‐X.
Published: April 2011

DRB1*04:94N allele was different from DRB1*04:03:01 at position 317 C>A and 321 C>A.
A chromatographically purified human TGF‐β1 fraction from virally inactivated platelet lysates
Authors: Burnouf T. , Chang C.‐W. , Kuo Y.‐P. , Wu Y.‐W. , Tseng Y.‐H. , Su C.‐Y.
Published: April 2011

Background and Objectives  TGF‐β1 exerts important physiological functions in osteogenesis and chondrogenesis and may be of therapeutic interest. The aim of this work was to develop a scalable purification process of TGF‐β1 from virally inactivated human platelets.

Study Design and Methods  Apheresis platelet concentrates (N = 12) were solvent/detergent (S/D) treated (1% TnBP/1% Triton X‐45; 31 °C) and the resulting platelet lysates were clarified by oil extraction and centrifugation, then chromatographed on an anion‐exchange DEAE‐Sepharose Fast‐Flow column equilibrated in a PBS buffer, pH 7·5. The column was washed to eliminate unbound proteins and the S/D agents. Bound proteins were eluted using a 1 M NaCl–PBS buffer pH 7·5 (DEAE‐eluate). The content in TGF‐β1, PDGF‐AB, VEGF, IGF‐1, EGF, and b‐FGF was measured by ELISA. Proteins, lipids, and S/D agents were assessed. Protein profile was determined by SDS‐PAGE under reduced or non‐reduced conditions.

Results  Most proteins, including albumin and immunoglobulins G, A, and M did not bind to the DEAE column as evidenced also by SDS‐PAGE. Essentially all PDGF, VEGF, and IGF were in the breakthrough. The DEAE‐eluate contained close to 60% of the TGF‐β1 at a mean concentration of about 102 ng/ml, whereas EGF, b‐FGF were at about 0·72 and 0·18 ng/ml, respectively. The content in TnBP and Triton X‐45 was <2 ppm.

Conclusion  A fraction enriched in TGF‐β1 can be prepared from virally inactivated human platelet lysates using an easily scale process. Its interest in regenerative medicine and cell therapy will be evaluated in further studies.
Variation in Podosphaera xanthii on Cucurbits in Southern Italy
Authors: Miazzi Monica , Laguardia Cataldo , Faretra Francesco
Published: April 2011

Powdery mildews, caused by Golovinomyces cichoracearum and Podosphaera xanthii, are the most common and severe diseases of cucurbits in the Mediterranean basin. In southern Italy, only P. xanthii is apparently present. However, information on its distribution and population biology is scanty, although it would be crucial for a more rational disease control. Studies addressing physiological races, mating types and RAPD analysis were carried out on 82 isolates of P. xanthii sampled in 34 cucurbit fields from Apulia (southern Italy). A set of eight differential melon genotypes were used to discriminate physiological races of the fungus. In particular, 13% of the tested isolates belonged to physiological race 2 FR, 30% to race 5, 25% to race 1, 10% to race 3, 5% to race 4, 1% to race 0 and 16% to undetermined races, whereas only one of the two mating types (MAT1‐2) of the fungus was detected, and RAPD analysis showed a quite broad variation within fungal isolates.
Silicon Suppresses Fusarium Crown and Root Rot of Tomato
Authors: Huang Cheng‐Hua , Roberts Pamela D. , Datnoff Lawrence E.
Published: April 2011

Fusarium oxysporum f.sp. radicis‐lycopersici, the causal agent of Fusarium crown and root rot (FCRR), is a serious soilborne disease of tomato. Soil fumigation and host resistance may reduce the impact of this disease, but other alternative management strategies are needed because these options may not always be available or effective. The purpose of this study was to determine the potential of silicon (Si) to reduce the disease severity of FCRR. Seven‐day‐old seedlings of Bonny Best tomato, susceptible to FCRR, were transplanted in sand culture amended with Hoagland’s nutrient solution with (+Si) or without (−Si) 100 mg Si/l. At 3 weeks after transplanting, three inoculum concentrations 0, 106 and 107 conidia/plant were used to inoculate the seedlings. Disease severity and silicon concentration were evaluated at 4 weeks after inoculation. Disease progress over time was investigated using the seedlings amended with Si or without Si and inoculated with 0 or 106 conidia/plant. Disease severity was evaluated at 2, 3, 4 and 6 weeks after inoculation. After rating disease, evaluated plants were divided into shoots and roots for silicon concentration analysis. Si significantly reduced the severity of FCRR on the stem of tomato at 4 weeks after inoculation. Results of disease progress suggested that the decrease in the disease severity of FCRR by Si amendment was probably due to a delay in onset in initial infection of roots and the movement of the pathogen from roots to stems. Si contents of roots and shoots were significantly higher in tomato plants supplied with Si than in those without Si. Moreover, the increase in the Si content of roots was significantly correlated with the reduction of disease severity of root, crown and stem, indicating a silicon‐mediated resistance. Supplying Si to tomato seedlings can reduce the disease severity of FCRR, providing an alternative disease management strategy.
Detrital heavy minerals from Lower Jurassic clastic rocks in the Joetsu area, central Japan: Paleo‐Mesozoic tectonics in the East Asian continental margin constrained by limited chloritoid occurrences in Japan
Authors: KAMIKUBO HIROSHI , TAKEUCHI MAKOTO
Published: April 2011

Detrital chloritoids were extracted from the Lower Jurassic sandstones in the Joetsu area of central Japan. The discovery of detrital chloritoids in the Joetsu area, in addition to two previous reports, confirms their limited occurrence in the Jurassic strata of the Japanese islands. This finding emphasizes the importance of the denudation of chloritoid‐yielding metamorphic belts in Jurassic provenance evolution, in addition to a change from an active volcanic arc to a dissected arc that has already been described. Possible sources for the detrital chloritoids from the Jurassic sandstones are the Permo–Triassic chloritoid‐yielding metamorphic rocks distributed in dispersed tectonic zones (Hida, Unazuki, Ryuhozan and Hitachi Metamorphic Rocks), which are in fault contact with Permian to Jurassic accretionary complexes in the Japanese islands. This is because all of these pre‐Jurassic chloritoid‐yielding metamorphic rocks have a Carboniferous–Permian depositional age and a Permo–Triassic metamorphic age, whereas a Permian–Triassic metamorphic age on the Hitachi Metamorphic Rocks remains unreported. In addition, most metamorphic chloritoids imply a former stable land surface that has evolved into an unstable orogenic area. Therefore, the chloritoid‐yielding metamorphic rocks might form a continuous metamorphic belt originating from a passive continental margin in East Asia. Evidence from paleontological and petrological studies indicates that the Permo–Triassic metamorphic belt relates to a collision between the Central Asian Orogenic Belt and the North China Craton. The evolution of the Permian–Jurassic provenance of Japanese detrital rocks indicates that the temporal changes in detritus should result from sequences of collision‐related uplifting processes.