bluuebunny/crossref_metadata_2025 huggingface dataset:
High-speed shock-wave investigation in rarefied gas
Authors: Masoud M. , El-Khalafawy T.A. , Souprunenko V.A.
Published: January 2011

High-speed shock-wave propagation in a cylindrical tube at low initial gas pressure has been investigated. A shock-wave was excited by fast magnetic compression of a plasma in a conical θ-pinch-type electrodeless device. The Mach number varied from 10 to 100, and the initial pressure from 20 μm Hg to 250 μm Hg. At high initial pressures the shock-wave properties were identical to those of a ‘snow-plough’ model. At low pressures an anomalous wave attenuation was observed which could not be explained by the existing theory. The shock-front width is in good agreement with that predicted by the ion-ion collision theory.
Noise in collision-free alkali metal plasmas
Authors: Little P.F. , Middleton C.R.
Published: January 2011

Oscillations in alkali metal plasmas generated by contact ionization have been attributed to unstable drift waves both in collision-free and collision-dominated plasmas. In the early experiments, however, the influence of the radial electric field Er in causing rotation of the plasma column was ignored. In later work with collisional plasmas, measured Er values were used to calculate frequencies in the rest-frame of the plasma and so demonstrate unstable collisional driftwaves.

Measurements are reported on collision-free potassium and caesium plasmas. The radial electric field causes a Doppler shift comparable with the frequencies observed and often larger than the predicted frequency of the fastest growing drift wave. When this is taken into account the frequencies observed in potassium are within a factor of two of those predicted for the collisionless drift instability and the radial distribution of the density fluctuations shows a peak away from the edge of the column. Other features are consistent with the interpretation of the noise in potassium as due to the drift instability. In caesium edge effects predominate and the cause of the enhanced noise is not the drift instability.
Non-linear theory of Cherenkov excitation of a plasma by a modulated charged-particle beam
Authors: Kurilko V.I. , Ullschmied J.
Published: January 2011

The authors consider the non-linear problem of the excitation of a plasma resonator by the Cherenkov emission of a density-modulated, injected beam of charged particles. It is assumed that the beam current and the resonator length are small and that the particle energy is large, so that the transit time is small compared with the characteristic field rise time. The modulation frequency is assumed to be equal to one of the natural frequencie s of the resonator. The main non-linear effect is considered to be the reciprocal influence of the excited field on the motion of the beam particles; the plasma is assumed to be linear. The authors derive two non-linear equations of first order which determine in this approximation the time-dependence of the amplitude and phase of the field in the resonator.

The maximum field amplitude and the corresponding phase value are found, and estimates are made of the pulse duration necessary to reach the maximum and of the average beam particle energy losses per pulse.
Trapped particle instabilities in toroidal systems
Authors: Pogutse O.P.
Published: January 2011

The paper is a continuation of the study of collisionless instabilities due to particle trapping. Particular attention is paid to the effects which promote stabilization of this instability. The author considers in detail the influence of: 1. unequal ion and electron temperatures; 2. finite orbits; 3. circulating particles; 4. temperature gradient. It is found that it is extremely difficult to achieve complete stabilization of ‘trapped-particle’ instabilities. However, the various stabilizing factors affect the instability most strongly when the particles have different temperatures
Plasma Instabilities in Astrophysics (Report of the Asilomar Conference, Pacific Grove, Calif., USA, 14–17 October 1968)
Authors: Sturrock P.A. , Woltjer L.
Published: January 2011

The existence and development of the scientific discipline now known as plasma physics owe much to its interaction with astrophysics. Many of the concepts of plasma physics were first discussed i n an astrophysical setting by Alfvén, Chapman, Cowling, Fermi and Spitzer. Within the last twenty years, there has been a tremendous increase – both in scope and in detail – in our understanding of the plasma state and in our knowledge of the astrophysical world. Although astronomers provide a wealth of significant problems, and plasma physicists provide a battery of powerful concepts and theories, the great opportunity of bringing plasma theories to bear upon astronomical problems has not been fully exploited. It was in recognition of this situation that a four day conference was held in October 1968 at Asilomar, California, to bring together three different groups of people: plasma physicists, astronomers and theoretical astrophysicists. To reduce the amount of material to be covered at the conference, discussion was confined to the role of plasma instabilities in astrophysics.
Thermonuclear future of the Tokamak magnetic confinement device
Authors: Hubert P.
Published: January 2011

A possible extrapolation of the Tokamak principle towards a thermonuclear reactor raises many problems among which stress is laid on the minimum values required for the equilibrium and stability parameters. Some technological requirements are confronted with the most recent theoretical developments, revealing the existence of a small domain inside of which both points of view may be, perhaps, simultaneously satisfied.

The operation of the reactor would have to be discontinuous but each cycle might conceivably include a plateau lasting about 103 s. A major difficulty arises from the necessity to develop a heating method with an efficiency amounting to at least a few 10−3, keeping in mind other requirements about the uneasy reactor technology.
Non-linear decay processes of three electromagnetic waves in a warm magnetized plasma
Authors: Cano R. , Etievant C. , Fidone I. , Granata G.
Published: January 2011

In this paper we discuss the wave-wave coupling of two high-frequency electromagnetic waves launched into a warm plasma across the constant confining magnetic field using the Maxwell-Vlasov equations for electrons. Specifically, we consider the generation of an ordinary wave by the interaction of an extraordinary and an ordinary wave and the generation of an extraordinary wave by the interaction of two ordinary ones. The decay conditions and the amplitudes of the secondary waves are discussed numerically for different values of the electron temperature.
Methods of determining the density and temperature distribution of a plasma using electromagnetic waves
Authors: Nemov V.V. , Sizonenko V.L. , Stepanov K.N. , Teichmann J.
Published: January 2011

The authors consider a number of methods of determining the density and temperature distributions along the radius of a plasma cylinder.

Determination of the electron density and temperature distributions by measuring the electron cyclotron damping or the phase of an electromagnetic wave passing in a straight line through a plasma cylinder as a function of the “sighting” distance. If the electron velocity distribution is not Maxwellian, additional measurements of the absorption or the phase as a function of the magnetic field or of the angle between the direction of the ray and the magnetic field enable one to find the electron velocity distribution function along the magnetic field at each point in the plasma cylinder.

Determination of the plasma density distribution from the fraction of a microwave ray passing through a plasma in a direction perpendicular to the magnetic field, and determination of the effective collision frequency distribution from damping of the intensity of the refracted ray.

Determination of the temperature of a plasma in a strong magnetic field from the measured frequency-dependence of the absorption of low-frequency electromagnetic waves under conditions of acoustic resonance.
Expansion and thermalization processes of plasma flow on the BSG-II device
Authors: Uchida T. , Miyamoto K. , Fujita J. , Leloup C. , Kawasaki S. , Inoue N. , Suzuki Y. , Adati K.
Published: January 2011

The expansion process of a collision-dominated theta-pinch plasma in a homogeneous magnetic channel and the thermalization process of the kinetic energy of this plasma flow by a magnetic mirror field are studied on the BSG-II device. Previously it was reported that shock phenomena due to a mirror field were observed by several methods of measurement. In this paper four experimental results are presented: (1) the expansion of plasma along the homogeneous magnetic channel is adiabatic; it is well described by a model for one-dimensional isentropic flow of collision-dominated plasma; (2) the flow is supersonic and the occurrence of a shock in front of the mirror field is in accordance with a criterion concerning the supersonic-sonic transition of plasma flow; (3) the rate of plasma loss through the mirror field is reduced by the occurrence of the shock; (4) the values of the plasma parameters measured before and behind the shock front satisfy the Rankine-Hugoniot relations, though plasma pressure, flow velocity and Mach number are time-dependent.
Electrical conductivity of plasma in a spatially inhomogeneous magnetic field
Authors: Hinton F.L. , Oberman C.
Published: January 2011

The electrical conductivity of plasma in a strong spatially inhomogeneous magnetic field has been calculated using the small-gyroradius approximation to the kinetic equation. The current which flows along the magnetic lines is the sum of two parts, one due to the time-independent applied electric field, and the other (secondary currents) associated with gradient-B drifts across the lines. The first part gives the electrical conductivity. It has a non-local dependence on the electric field, when the mean free path is not short compared with the scale length for magnetic variations along the field lines. The kinetic equation is solved by a perturbation technique in the long-mean-free-path limit, and an explicit expression for the conductivity is obtained. The main result is that the inhomogeneity reduces the conductivity approximately by the fraction of trapped particles.
Experimental measurements of the characteristics of normal ionizing shock waves
Authors: Cross R.C. , James B.W. , Watson-Munro C.N.
Published: January 2011

A cylindrical shock tube has been used to study normal ionizing shock waves propagating, parallel to a steady axial magnetic field, into hydrogen gas at a neutral pressure of 100 mtorr. The shock velocity and post-shock parameters such as magnetic and electric fields, particle density and electron temperature are compared with theoretical calculations of these quantities obtained from the conservation equations and a modified form of the Chapman-Jouguet hypothesis. For the purposes of this calculation it was assumed that the Saha equation was applicable to the plasma. Over a range of steady axial magnetic fields from 0.65 kG to 12.5 kG and discharge currents from 20 to 160 kA, good agreement has been obtained between theory and experiment for shock velocities and for electric fields both behind and ahead of the shock. Density measurements display the predicted theoretical trend, but the measured compression ratios across the shock are low, implying a loss of particles during the ionizing process.
Electrostatic plugging of open-ended magnetic containment systems
Authors: Ware A.A. , Faulkner J.E.
Published: January 2011

The results of a theoretical study of the use of electrostatic fields to suppress the plasma losses from magnetic cusps or mirrors are reported. Numerical estimates are given for the maximum plasma densities which can be contained. Assuming stability, the use of electrostatic fields, combined with controlled electron and ion beam injection, makes it possible t o generate cusps with a width of 4 ρe, where ρe is the electron Larmor radius. With such narrow cusps, densities which are sufficiently high for a fusion reactor can be contained electrostatically. High values of the electric stress tensor (E2/8π) are required near the positive electrodes but the magnitude of these values is shown to be appreciably less than the plasma pressure and to be within practical limits. When the electrostatic fields are combined with a non-adiabatic cusp magnetic field, a form of particle beam injection is possible which is orders of magnitude more efficient than existing methods. The main body of the plasma should have a high degree of stability; the only weak regions for stability are in the cusps, where the electrons have been separated from the ions. The conditions in the cusps are greatly different from any model which has been treated by stability theory; the finite dimensions and non-uniformity in both the longitudinal and transverse directions will have stabilizing effects and the resultant stability of the electron cusps is an open question.
Rational points of universal curves
Authors: Hain Richard
Published: January 2011

Suppose that

k
k

is a field of characteristic zero and that

g
+
n
>
2

g+n>2

. The universal curve

C
C

of type

(
g
,
n
)

(g,n)

is the restriction of the universal curve to the generic point

Spec
⁡
k
(

M

g
,
n

)

\operatorname {Spec} k(\mathcal {M}_{g,n})

of the moduli stack

M

g
,
n

\mathcal {M}_{g,n}

of

n
n

-pointed smooth projective curves of genus

g
g

. In this paper we prove that if

g
≥
3

g \ge 3

, then its set of rational points

C
(
k
(

M

g
,
n

)
)

C(k(\mathcal {M}_{g,n}))

consists only of the

n
n

tautological points. We then prove that if

g
≥
5

g\ge 5

and

n
=
0

n=0

, then Grothendieck’s Section Conjecture holds for

C
C

when, for example,

k
k

is a number field or a non-archimedean local field. When

n
>
0

n>0

, we consider a modified version of Grothendieck’s conjecture in which the geometric fundamental group of

C
C

is replaced by its

ℓ
\ell

-adic unipotent completion. We prove that if

k
k

is a number field or a non-archimedean local field, then this modified version of the Section Conjecture holds for all

g
≥
5

g \ge 5

and

n
≥
1

n \ge 1

.
Clinical and Molecular Pharmacology of Etomidate
Authors: Forman Stuart A. , Warner David S.
Published: January 2011

This review focuses on the unique clinical and molecular pharmacologic features of etomidate. Among general anesthesia induction drugs, etomidate is the only imidazole, and it has the most favorable therapeutic index for single-bolus administration. It also produces a unique toxicity among anesthetic drugs: inhibition of adrenal steroid synthesis that far outlasts its hypnotic action and that may reduce survival of critically ill patients. The major molecular targets mediating anesthetic effects of etomidate in the central nervous system are specific γ-aminobutyric acid type A receptor subtypes. Amino acids forming etomidate binding sites have been identified in transmembrane domains of these proteins. Etomidate binding site structure models for the main enzyme mediating etomidate adrenotoxicity have also been developed. Based on this deepening understanding of molecular targets and actions, new etomidate derivatives are being investigated as potentially improved sedative-hypnotics or for use as highly selective inhibitors of adrenal steroid synthesis.
Genetic Control of a Transition from Black to Straw-White Seed Hull in Rice Domestication
Authors: Zhu Bo-Feng , Si Lizhen , Wang Zixuan , Jingjie Zhu Yan Zhou , Shangguan Yingying , Lu Danfeng , Fan Danlin , Li Canyang , Lin Hongxuan , Qian Qian , Sang Tao , Zhou Bo , Minobe Yuzo , Han Bin
Published: January 2011

The genetic mechanism involved in a transition from the black-colored seed hull of the ancestral wild rice (Oryza rufipogon and Oryza nivara) to the straw-white seed hull of cultivated rice (Oryza sativa) during grain ripening remains unknown. We report that the black hull of O. rufipogon was controlled by the Black hull4 (Bh4) gene, which was fine-mapped to an 8.8-kb region on rice chromosome 4 using a cross between O. rufipogon W1943 (black hull) and O. sativa indica cv Guangluai 4 (straw-white hull). Bh4 encodes an amino acid transporter. A 22-bp deletion within exon 3 of the bh4 variant disrupted the Bh4 function, leading to the straw-white hull in cultivated rice. Transgenic study indicated that Bh4 could restore the black pigment on hulls in cv Guangluai 4 and Kasalath. Bh4 sequence alignment of all taxa with the outgroup Oryza barthii showed that the wild rice maintained comparable levels of nucleotide diversity that were about 70 times higher than those in the cultivated rice. The results from the maximum likelihood Hudson-Kreitman-Aguade test suggested that the significant reduction in nucleotide diversity in rice cultivars could be caused by artificial selection. We propose that the straw-white hull was selected as an important visual phenotype of nonshattered grains during rice domestication.
Resolving the Compartmentation and Function of C4 Photosynthesis in the Single-Cell C4 Species Bienertia sinuspersici
Authors: Offermann Sascha , Okita Thomas W. , Edwards Gerald E.
Published: January 2011

Bienertia sinuspersici is a land plant known to perform C4 photosynthesis through the location of dimorphic chloroplasts in separate cytoplasmic domains within a single photosynthetic cell. A protocol was developed with isolated protoplasts to obtain peripheral chloroplasts (P-CP), a central compartment (CC), and chloroplasts from the CC (C-CP) to study the subcellular localization of photosynthetic functions. Analyses of these preparations established intracellular compartmentation of processes to support a NAD-malic enzyme (ME)-type C4 cycle. Western-blot analyses indicated that the CC has Rubisco from the C3 cycle, the C4 decarboxylase NAD-ME, a mitochondrial isoform of aspartate aminotransferase, and photorespiratory markers, while the C-CP and P-CP have high levels of Rubisco and pyruvate, Pidikinase, respectively. Other enzymes for supporting a NAD-ME cycle via an aspartate-alanine shuttle, carbonic anhydrase, phosophoenolpyruvate carboxylase, alanine, and an isoform of aspartate aminotransferase are localized in the cytosol. Functional characterization by photosynthetic oxygen evolution revealed that only the C-CP have a fully operational C3 cycle, while both chloroplast types have the capacity to photoreduce 3-phosphoglycerate. The P-CP were enriched in a putative pyruvate transporter and showed light-dependent conversion of pyruvate to phosphoenolpyruvate. There is a larger investment in chloroplasts in the central domain than in the peripheral domain (6-fold more chloroplasts and 4-fold more chlorophyll). The implications of this uneven distribution for the energetics of the C4 and C3 cycles are discussed. The results indicate that peripheral and central compartment chloroplasts in the single-cell C4 species B. sinuspersici function analogous to mesophyll and bundle sheath chloroplasts of Kranz-type C4 species.
4‐(Methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone promoted gastric cancer growth through prostaglandin E receptor (EP2 and EP4) in vivo and in vitro
Authors: Shin Vivian Y. , Jin Hong C. , Ng Enders K. O. , Cho Chi H. , Leung Wai K. , Sung Joseph J. Y. , Chu Kent‐Man
Published: January 2011

Prostaglandin E (EP) receptor is positively related with COX‐2, which is involved in cancer biology. A mechanistic study on how 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone (NNK) promotes gastric carcinogenesis is lacking. Recently, we found that nicotine promoted tumor growth through upregulation of the COX‐2/prostaglandin E2 pathway. This extended our study on the involvement of EP receptors in gastric carcinogenesis. Both in vitro and in vivo studies showed that NNK promoted cancer cell growth with concomitant EP2 and EP4 upregulation. We found that NNK stimulated vascular endothelial growth factor (VEGF) and angiogenesis, but suppressed apoptosis by increasing Bcl2 and decreasing caspase‐3 expressions. Both EP2 and EP4 siRNA significantly impaired these tumorigenic actions of NNK in xenograft tumor. Cell cycle analysis showed that NNK increased S phase entry with increased cyclin D1 and the associated cyclin‐dependent kinase 4/6, and downregulation of p21 and p27. The p38 phosphorylation was EP2/4‐dependent, and SB203580 (p38 inhibitor) suppressed NNK‐induced prostaglandin E2, VEGF, and cell proliferation. Antagonists of EP2 or EP4 abolished the elevated VEGF and VEGF receptor‐2. These data strongly indicate that EP2/4 are important for NNK‐promoted gastric carcinogenesis, thus providing a framework for future evaluation of EP antagonist(s) as anticancer drugs for smokers. (Cancer Sci 2011; 102: 926–933)
Loss of E‐cadherin in mouse gastric epithelial cells induces signet ring‐like cells, a possible precursor lesion of diffuse gastric cancer
Authors: Mimata Ayako , Fukamachi Hiroshi , Eishi Yoshinobu , Yuasa Yasuhito
Published: January 2011

Alterations in the E‐cadherin gene are associated with sporadic and hereditary diffuse‐type gastric cancer. To determine how the loss of function of E‐cadherin affects gastric epithelial cell phenotypes, we generated transgenic mice using the Cre‐loxP system in which the E‐cadherin gene is specifically knocked out in the parietal cell lineage. In the transgenic mice, expression of E‐cadherin was lost or reduced in proton pump‐expressing parietal cells, which became round in shape and were pushed out of the glands to accumulate in the stromal area. Additionally, gastric mucosa exhibited hyperplasia from 3 months in the mice, some cells of which later became positive for trefoil factor 2, a marker of spasmolytic polypeptide‐expressing metaplasia. From 6 months, E‐cadherin‐negative/proton pump‐negative cells appeared from the parietal cell lineage, which increased in number to form cell clusters. Moreover, signet ring‐like cells, which are morphologically similar to signet ring carcinoma cells, were found in the cell clusters from 12 months. However, no invasive gastric adenocarcinomas were found in the E‐cadherin‐deficient mice, even at 24 months or later. These data indicate that the loss of E‐cadherin induces possible pre‐cancerous lesions in the gastric mucosa but may not be sufficient for its malignant conversion. (Cancer Sci 2011; 102: 942–950)
Postoperative transient tetraplegia in two patients caused by cervical spondylotic myelopathy
Authors: Kudo T. , Sato Y. , Kowatari K. , Nitobe T. , Hirota K.
Published: January 2011

We report two patients with cervical spondylotic myelopathy following non‐cervical spine surgery. These cases revealed postoperative transient tetraplegia with respiratory insufficiency despite optimal anaesthetic management. Both patients showed no limitation of their neck movement at pre‐operative airway examination. In addition, their necks had never been overextended during anaesthesia including tracheal intubation. However, postoperative magnetic resonance imaging showed cervical spondylotic myelopathy. Cervical disc herniation and protrusion of a hypertrophic ligamentum flavum caused spinal canal cord compression, and, these may lead to tetraplegia and phrenic nerve impairment. Their muscle weakness gradually improved and completely recovered the following morning. We should consider the existence of cervical spondylosis in the elderly patients over the age of 60 years.
A novel genetic marker of the ovomucoid gene associated with hatchability in Tsaiya ducks (Anas platyrhynchos)
Authors: Huang H.‐L. , Cheng Y.‐S. , Huang C.‐W. , Huang M.‐C. , Hsu W.‐H.
Published: January 2011

Transcriptome analysis using a cDNA microarray was performed to identify differentially expressed genes that are correlated with hatchability, and a new PCR‐RFLP marker of high hatchability among the identified genes was observed. We used the cDNA microarray technique for gene expression profiling of the magnum epithelium of laying Tsaiya ducks, and several regulated genes associated with hatchability were found. The results of real‐time PCR and Western blotting analysis confirmed that the mRNA and protein levels of ovomucoid in the magnum epithelium of animals in the low‐hatchability group were significantly higher than the levels in the high‐hatchability group (P < 0.05). Primers TovF1 and TovR1, designed according to the ovomucoid EST sequence, were used to amplify genomic DNA samples of different individual Tsaiya ducks, and sequence analysis of the amplified DNA products showed deletion among the ducks from the low‐hatchability group. Primers TovF2 and TovR2 were used to perform PCR‐RFLP analysis on the amplified DNA products to classify the ducks into +/+, +/− and −/− genotypes. The animals of +/+ and +/− genotypes were identified as having significantly higher hatchability than those of the −/− genotype (P < 0.05). In contrast, no differences were observed between genotypes in terms of fertility, duration of fertility, egg weight or total number of eggs. Our results indicated that a novel PCR‐RFLP marker of high hatchability, an ovomucoid gene polymorphism, can be used as a genetic marker for marker‐assisted selection to improve hatchability in Tsaiya ducks.
Quantitative trait loci for fatness at growing and reproductive stages in Iberian × Meishan F2 sows
Authors: Tomás A. , Ramírez O. , Casellas J. , Muñoz G. , Sánchez A. , Barragán C. , Arqué M. , Riart I. , Óvilo C. , Noguera J. L. , Amills M. , Rodríguez C.
Published: January 2011

A considerable number of fatness QTL have been identified in growing pigs, but there is a lack of knowledge about the genetic architecture of this trait in gilts and sows. We have performed a genome scan, in 255 Iberian × Meishan F2 sows, for backfat thickness (BF) at 150 (BF150) and 210 (BF210) days of age, 30 days after conception (BF30) and 7–10 days before farrowing (BFbf). We have found one BF150 QTL in SSC6 (120 cM) that was highly significant (P < 0.001) at the chromosome‐wide level and suggestive at the genome‐wide level (P < 0.1). Ten additional chromosome‐wide significant QTL were found for sow BF150 (SSC1, SSC13), BF210 (SSC6, SSC8, SSC15), BF30 (SSC5, SSC6) and BFbf (SSC1, SSC6, SSC13). The location of several of the BF QTL varied depending on the growing and reproductive status of the sow, suggesting that part of these genetic effects may have a temporal pattern of phenotypic expression.
Prediction and evaluation of fetal toxicity induced by NSAIDs using transplacental kinetic parameters obtained from human placental perfusion studies
Authors: Shintaku Kyohei , Hori Satoko , Satoh Hiroki , Tsukimori Kiyomi , Nakano Hitoo , Fujii Tomoyuki , Taketani Yuji , Ohtani Hisakazu , Sawada Yasufumi
Published: January 2011

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• The use of nonsteroidal anti‐inflammatory drugs (NSAIDs) in full‐term pregnant women leads to fetal or neonatal toxicity. However, the differences in fetal toxicity among NSAIDs remain to be fully investigated.

• Therefore, the ability to predict fetal toxicity of NSAIDs quantitatively at full‐term pregnancy would be of clinical value.

WHAT THIS STUDY ADDS

• This study presents a novel approach to predict quantitatively the fetal risk of NSAIDs administered to the mother.

• This study shows that the fetal risk of diclofenac is higher than that of salicylic acid and antipyrine using the novel method.

• Human placental perfusion study and pharmacokinetic/pharmacodynamic analysis may provide basic data for predicting human fetal toxicity of drugs.

AIM The use of nonsteroidal anti‐inflammatory drugs (NSAIDs) in full‐term pregnant women leads to fetal or neonatal toxicity, such as constriction of the ductus arteriosus (DA) and persistent pulmonary hypertension in the newborn. The aim of this study was to predict quantitatively the fetal toxicity of three NSAIDs (antipyrine, salicylic acid and diclofenac) using the transplacental pharmacokinetic parameters obtained from our previous placental perfusion studies.

METHODS Human fetal plasma concentration profile after oral administration of each NSAID to the mother was estimated using the transplacental pharmacokinetic parameters and pharmacokinetic parameters in adult women. The fetal plasma concentration–response relationship for the three NSAIDs was estimated by pharmacokinetic/pharmacodynamic analysis of the results of previous studies investigating the effects of NSAIDs on the ratio of inner diameter of the DA to that of the pulmonary artery (DA/PA) in rats and the plasma concentration profiles of NSAIDs in pregnant rats.

RESULTS The risk of constriction of the DA was well predicted by the model. Mean DA/PA ratio after oral administration of diclofenac to the mother was estimated to be 39.0%, whereas both of the corresponding values after oral administration of antipyrine and salicylic acid were estimated to be 5.9%. These results suggest that the fetal risk of diclofenac is higher than those of salicylic acid and antipyrine.

CONCLUSIONS This study presents a novel approach to predict quantitatively the fetal risk of NSAIDs administered to the mother. Human placental perfusion study and pharmacokinetic/pharmacodynamic analysis may provide basic data for predicting human fetal toxicity of drugs.
Reproducibility of liver stiffness measurements in hepatitis C virus (HCV)‐infected patients in Egypt
Authors: Vignier N. , Esmat G. , Sharkawy A. E. , Hassany M. , Bonnard P. , Delarocque‐Astagneau E. , Said M. , Raafat R. , El‐Hoseiny M. , Fontanet A. , Mohamed M. K. , Vray M.
Published: January 2011

Summary.  Elastometry has demonstrated good accuracy, but little is known about its reproducibility. The aim of this study was to assess the intra‐ and inter‐operator reproducibility of liver stiffness measurement among hepatitis C virus (HCV)‐infected patients in Egypt. The study was conducted among HCV‐infected patients referred for treatment evaluation in two hepatitis treatment centres of Cairo. Two operators took liver stiffness measurement two times per patient the same day. Intra‐ and inter‐reproducibility were estimated by different methods: Bland and Altman graphics, variation coefficient, intraclass correlation coefficient and Kappa coefficient; 7.1 kPa was used as the threshold of significant (≥F2) fibrosis whenever needed. Fifty‐eight patients were included in the study, and 216 measurements were taken. Failure rate was 7% and associated with overweight. For a value of 7.1 kPa, the inter‐operator 95% limits of agreement were estimated at ±2.88 kPa. Intra‐ and inter‐operator coefficients of variation ranged between 11% and 15%, intraclass correlation coefficients [95% confidence interval] between 0.94 [0.86–0.97] and 0.97 [0.95–0.99], and Kappa coefficients between 0.65 [0.44–0.88] and 0.92 [0.81–1.00]. The reliability of liver stiffness measurement is questionable when considering the decision to initiate antiviral therapy because of the percentage of discordance between measurements is notable, especially in the intermediate fibrosis stages.
Lactococcal phage p2 ORF35‐Sak3 is an ATPase involved in DNA recombination and AbiK mechanism
Authors: Scaltriti Erika , Launay Hélène , Genois Marie‐Michelle , Bron Patrick , Rivetti Claudio , Grolli Stefano , Ploquin Mickael , Campanacci Valérie , Tegoni Mariella , Cambillau Christian , Moineau Sylvain , Masson Jean‐Yves
Published: January 2011

Virulent phages of the Siphoviridae family are responsible for milk fermentation failures worldwide. Here, we report the characterization of the product of the early expressed gene orf35 from Lactococcus lactis phage p2 (936 group). ORF35p2, also named Sak3, is involved in the sensitivity of phage p2 to the antiviral abortive infection mechanism AbiK. The localization of its gene upstream of a gene coding for a single‐strand binding protein as well as its membership to a superfamily of single‐strand annealing proteins (SSAPs) suggested a possible role in homologous recombination. Electron microscopy showed that purified ORF35p2 form a hexameric ring‐like structure that is often found in proteins with a conserved RecA nucleotide‐binding core. Gel shift assays and surface plasmon resonance data demonstrated that ORF35p2 interacts preferentially with single‐stranded DNA with nanomolar affinity. Atomic force microscopy showed also that it preferentially binds to sticky DNA substrates over blunt ends. In addition, in vitro assays demonstrated that ORF35p2 is able to anneal complementary strands. Sak3 also stimulates Escherichia coli RecA‐mediated homologous recombination. Remarkably, Sak3 was shown to possess an ATPase activity that is required for RecA stimulation. Collectively, our results demonstrate that ORF35p2 is a novel SSAP stimulating homologous recombination.
Reliability of routine clinical measurements of neonatal circumferences and research measurements of neonatal skinfold thicknesses: findings from the Born in Bradford study
Authors: West Jane , Manchester Ben , Wright John , Lawlor Debbie A , Waiblinger Dagmar
Published: January 2011

West J, Manchester B, Wright J, Lawlor DA, Waiblinger D. Reliability of routine clinical measurements of neonatal circumferences and research measurements of neonatal skinfold thicknesses: findings from the Born in Bradford study. Paediatric and Perinatal Epidemiology 2011.

Assessing neonatal size reliably is important for research and clinical practice. The aim of this study was to examine the reliability of routine clinical measurements of neonatal circumferences and of skinfold thicknesses assessed for research purposes. All measurements were undertaken on the same population of neonates born in a large maternity unit in Bradford, UK. Technical error of measurement (TEM), relative TEM and the coefficient of reliability are reported.

Intra‐observer TEMs for routine circumference measurements were all below 0.4 cm and were generally within ±2‐times the mean. Inter‐observer TEM ranged from 0.20 to 0.36 cm for head circumference, 0.19 to 0.39 cm for mid upper arm circumference and from 0.39 to 0.77 cm for abdominal circumference. Intra and inter‐observer TEM for triceps skinfold thickness ranged from 0.22 to 0.35 mm and 0.15 to 0.54 mm, respectively. Subscapular skinfold thickness TEM values were 0.14 to 0.25 mm for intra‐observer measurements and 0.17 to 0.63 mm for inter‐observer measurements. Relative TEM values for routine circumferences were all below 4.00% but varied between 2.88% and 14.23% for research skinfold measurements. Reliability was mostly between 80% and 99% for routine circumference measurements and ≥70% for most research skinfold measurements.

Routine clinical measurements of neonatal circumferences are reliably assessed in Bradford. Assessing skinfolds in neonates has variable reliability, but on the whole is good. The greater intra‐observer, compared with inter‐observer, reliability for both sets of measurements highlights the importance of having a minimal number of assessors whenever possible.
Genetic diversity of the wheat yellow rust population in Pakistan and its relationship with host resistance
Authors: Bahri B. , Shah S. J. A. , Hussain S. , Leconte M. , Enjalbert J. , de Vallavieille‐Pope C.
Published: January 2011

Yellow rust, caused by Puccinia striiformis f.sp. tritici (PST), is an important disease that threatens wheat production in Pakistan. This study was designed to explore the virulence and simple sequence repeat (SSR) diversity of the Pakistani PST population and the ongoing selective pressures of widely grown wheat cultivars. Analyses of 49 isolates sampled from the North‐West Frontier Province of Pakistan led to the identification of 12 distinct pathotypes. The virulence frequencies of v2 (virulent against Yr2), v6, v7, v9, vSU and v27 ranged from 63% to 100%. Virulences v3, v4, v17 and vSD were uncommon, whilst v5, v10, v15, v24, v32 and vSp were not detected. The pathotypes thus described were then classified into 27 distinct genotypes. Bayesian structure analysis clustered these genotypes into five groups (in addition to one hybrid isolate) which represent three distinct lineages of the SSR‐based phylogenetic tree. Of the studied isolates, 80%, represented by three predominant pathotypes (P1–P3), belonged to the same characteristic Pakistani lineage, whilst the other isolates were close to either a Mediterranean lineage or a Northern European lineage. Genetic recombination was detected within P2 isolates. Resistance genes postulated in 40 Pakistani wheat cultivars indicated the high frequency of Yr2, Yr6, Yr7, Yr9, Yr27 and YrSU. Only 11 cultivars were found to be resistant to P1–P3. Migration and varietal diversity factors might contribute to maintaining the currently high genetic diversity in Pakistani PST, and have serious regional implications for wheat improvement programmes.
Dolomite characteristics and diagenetic model of the Calcari Grigi Group (Asiago Plateau, Southern Alps – Italy): an example of multiphase dolomitization
Authors: DI CUIA RAFFAELE , RIVA ALBERTO , SCIFONI ANDREA , MORETTI ALESSANDRO , SPÖTL CHRISTOPH , CALINE BRUNO
Published: January 2011

A multidisciplinary study, conducted over the carbonate platform deposits of the Liassic Calcari Grigi Group (Southern Alps), highlighted how the use of outcrop analogues can contribute to better define the distribution of dolomitic bodies related to fault networks, to characterize the petrophysical properties of the dolomitic sequence and unravel a complex diagenetic history. This study was carried out in the Asiago Plateau (southernmost part of the eastern Southern Alps, northern Italy) which provides excellent outcrops of the Jurassic Calcari Grigi Group. The dolomitization of the Jurassic sequence is variable in terms of stratigraphic extension and geographic distribution. In the studied localities the dolomitization is generally limited to the Mount Zugna Formation and is characterized by an undulatory front, with ‘sub‐vertical dolomitic chimneys’ along the major faults. Within this unit, and often associated with faults, stacked high‐porosity and permeability bed‐parallel dolomitic bodies are developed that show excellent petrophysical properties. The dolomitic intervals are characterized by pervasive unimodal and patchy polymodal dolomite crystals. Thin section, cathodoluminescence, isotopic and fluid inclusion analyses were used to constrain the paragenetic evolution of the sequence which is similar in all the studied localities. The first dolomitization stage is marked by zoned dolomite crystals with a dull luminescent core. The porosity is thought to have increased after this stage, with dark blue luminescent dolomite accompanied by the corrosion of older crystals. The appearance of saddle dolomite marks the onset of the porosity reduction stage, ending with the infilling of vugs and the remaining open pores with calcite cement. The diagenetic evolution locally stopped at the saddle dolomite stage with the complete occlusion of the remaining pores. Paragenetic and fluid‐inclusion data suggest an evolutionary trend of increasing temperatures and decreasing salinity toward brackish fluids responsible for dolomite and calcite precipitation. The integration of the available data seem to indicate that the diagenetic evolution of the study area is related to: (i) the interplay between evolving fluids (from marine to brackish); (ii) the burial of the sequence (increasing temperature); and (iii) the evolution of the hydrogeological system (fault and fracture network, fluid mixing). This complex paragenetic evolution is strongly linked to the evolution of the porosity framework that evolved from a good, widespread network in the early stages of the burial history to a confined system in the later stages due to reduction of porosity by the deposition of late calcite and dolomite cements.
Modelling controls on aeolian dune‐field pattern evolution
Authors: EASTWOOD ERIN , NIELD JOANNA , BAAS ANDREAS , KOCUREK GARY
Published: January 2011

A second‐generation, source‐to‐sink cellular automaton‐based model presented here captures and quantifies many of the factors controlling the evolution of aeolian dune‐field patterns by varying only a small number of parameters. The role of sediment supply, sediment availability and transport capacity (together defined as sediment state) in the development and evolution of an aeolian dune‐field pattern over long time scales is quantified from model simulations. Seven dune‐field patterns can be classified from simulation results varying the sediment supply and transport capacity that control the type and frequency of dune interactions, the sediment availability of the system and, ultimately, the development of dune‐field patterns. This model allows predictions to be made about the range of sediment supply and wind strengths required to produce the dune‐field patterns seen in the real world. A new clustered dune‐field pattern is identified from model results and used to propose an alternative mechanism for the formation of superimposed dunes. Bedforms are hypothesized to cluster together, simultaneously forming two spatial scales of bedforms without first developing a large basal dune with small superimposed dunes. Manipulation of boundary conditions produces evolving dune fields with different spatial configurations of sediment supply. Trends of spacing and crest length increase with decreasing variability as the dune field matures. This simple model is a valuable tool which can be used to elucidate the dominant control of aeolian sediment state on the construction and evolution of aeolian dune‐field patterns.
Sedimentation and time‐of‐transition techniques for measuring grain‐size distributions in lagoonal flats: comparability of results
Authors: MOLINAROLI E. , DE FALCO G. , MATTEUCCI G. , GUERZONI S.
Published: January 2011

A comparative study was performed of three instruments used to measure the grain‐size distribution of thirty sediment samples from shallow lagoonal flats: the hydrometer, the Sedigraph 5100 and the CIS‐1. The hydrometer and Sedigraph are based on sedimentation whereas the CIS‐1 uses the time of transition. The percentage of the samples accounted for by the <8 μm fraction was not affected by the technique used, but this was not the case with the clay fraction (<2 μm). Due to its relative independence from the analytical method applied, the <8 μm fraction can be used in ternary diagram classifications. This fraction also has an environmental significance in coastal lagoons in terms of hydrodynamics, organic enrichment and macrozoobenthos assemblages. The linear relationships obtained in this study may provide useful operational indications for similar studies.
Accumulation of human EGF in nectar of transformed plants of Nicotiana langsdorffii × N. sanderae and transfer to honey by bees
Authors: Helsper J. P. F. G. , Ruyter‐Spira C. P. , Kwakman P. H. S. , Bleeker W. K. , Keizer L. C. P. , Bade J. B. , Te Velde A. A. , Zaat S. A. J. , Verbeek M. , Creemers‐Molenaar J.
Published: January 2011

Honey has been used successfully in wound healing for thousands of years. The peptide hormone human epidermal growth factor (hEGF) is also known to have a beneficial effect in various wound healing processes via mechanisms that differ from those for honey. In this study, we show that hEGF can be incorporated into honey via nectar. Plants of Nicotiana langsdorffii × N. sanderae were transformed with the gene for hEGF, equipped with a nectary‐targeted promoter and a signal sequence for secretion to nectar. These plants accumulated hEGF in the nectar. The maximum hEGF concentration recorded with ELISA in these plants is 2.5 ng·ml−1. There is a significant linear relationship (P < 0.001) between hEGF concentration and induction of hEGF‐receptor phosphorylation. Since the flower morphology of these plants did not allow production of honey from their nectar, we used feeding solutions, spiked with synthetic hEGF, to study transfer of this peptide into honey through bee activity. Transfer of hEGF from a feeding solution to honey by bees occurred with retention of the hEGF concentration and the capacity to induce hEGF‐receptor phosphorylation. These observations indicate that plants can function as a production platform for honey containing biologically active peptides, which may enhance wound healing and other biological processes.
Food resource use in sympatric juvenile plaice and flounder in estuarine habitats
Authors: Mariani Stefano , Boggan Ciara , Balata David
Published: January 2011

Environmental conditions in estuarine habitats can vary greatly and influence the composition of fish assemblages and their trophic interrelationships. We investigated feeding habits and patterns of diet overlap in juvenile plaice (Pleuronectes platessa) and flounder (Platichthys flesus) from two estuarine habitats in the Irish Sea. Plaice was found to vary its diet significantly across environments, whereas flounder exhibited a more consistent and homogeneous feeding pattern. Importantly, sympatric fish sampled at the same station were shown to reduce diet overlap. The results support the view that environmental heterogeneity in estuaries maintains a wide range of selective forces, the net outcome of which can produce a diverse array of feeding adaptations among interacting species.
The effect of temperature variability on ecological functioning of epifauna in the German Bight
Authors: Neumann Hermann , Kröncke Ingrid
Published: January 2011

Benthic epifauna was sampled in an area of 10 × 10 nautical miles in the German Bight. Samples were taken in January and July/August from 1998 to 2009. The ecological functioning of the epifaunal community was assessed using biological traits analysis (BTA). Twelve ecological traits of 26 epifaunal species were considered and analysed using non‐metric multidimensional scaling (nmMDS). Anomalies in the sea surface temperature (SST) close to the study area were mainly above the long‐term mean during the study period. SST was exceptionally high during the autumn months between 2002 and 2006. Additionally, the cold winter of 1995–96 was clearly reflected in strong negative SST anomalies. Trait composition changed in 2002, mainly due to a decreasing trend of traits related to an opportunistic life mode from 1998–2002. Traits related to reproduction showed a much clearer response to the high autumn SST anomalies from 2002 to 2006 than other traits. We concluded that the cold winter resulted in an increase in opportunistic species in the study area followed by characteristic post‐disturbance succession stages to the point of an established community in 2002. This indicates a recovery time of epifaunal communities in the German Bight of 7–8 years. Additionally, the results give evidence that climate‐induced variability of SST in the German Bight affects mainly the reproduction of epifaunal species rather than other traits such as feeding type.
Cytoplast containing reprogramming‐related factors from human embryonic stem cells arrested at metaphase
Authors: Du Lili , Lin Ge , Lu Guangxiu
Published: January 2011

Generating pluripotent stem cells directly from a patient’s somatic cells is one of the major methods to avoid rejection in future regenerative medicine. It is reported that human embryonic stem cells (hESCs) are able to reprogram the nuclei of fully differentiated human somatic cells, apparently conferring on them a pluripotent state. However, the ability of the cytoplasts from enucleated hESCs to reprogram somatic cells causes much controversy. Here we detect the location of pluripotency‐related factors such as Oct4/Nanog/Sox2 in the hESCs at division and non‐division stage and obtain the cytoplasts of hESCs by centrifugation. We demonstrate for the first time that the cytoplast from hESCs arrested at the division phase of cell the cycle contains the reprogramming factors and this kind of cytoplast can be obtained through gradient centrifugation. These give us direct proof of the possibility of reprogramming somatic cell using cytoplast of hESCs and make this a possible method for getting patient‐specific pluripotent cells without extrinsic DNA introduction.