bluuebunny/crossref_metadata_2025 huggingface dataset:
An overview on S-band erbium-doped fiber amplifiers
Authors: Harun S W , Dimyati K , Jayapalan K K , Ahmad H
Published: September 2006

An erbium-doped fiber amplifier (EDFA) for S-band
signal amplification is designed by using a depressed cladding
erbium-doped fiber (DC-EDF). The fiber's characteristics are
described in terms of the effects of the fiber spooling diameter
on the amplifier's performance. In this experiment, the spooling
diameter required for optimum amplifier gain was around 5–7 cm.
By using a typical two-stage configuration (with a 27 m long
DC-EDF and a 260 mW pump laser power), the maximum small signal
gain obtained was about 32 dB. Yet, by employing a double pass
amplifier configuration with a shorter DC-EDF length and a lower
pump laser power (15 m and 135 mW, respectively), a similar
maximum small signal gain of approximately 30 dB was achieved.
This improvement in gain characteristics however, incurred an
increased noise figure penalty of about 1 dB in comparison to
single-pass amplifier configurations. In order to reduce the
amplifier's noise figure while maintaining its high gain, a
partial double-pass S-band EDFA configuration was introduced. This
configuration provides a high 26.9 dB gain and an improved noise
figure comparable to a single pass configuration. Gain clamping in
S-band EDFAs are also demonstrated by utilizing a fiber Bragg
grating to form an oscillating laser at around 1530 nm. This
technique enables good gain clamping with a gain variation of less
than 1 dB.
Pharmacological characterization of psychosis‐like behavior in the MPTP‐lesioned nonhuman primate model of Parkinson's disease
Authors: Visanji Naomi P. , Gomez‐Ramirez Jordi , Johnston Tom H. , Pires Donna , Voon Valerie , Brotchie Jonathan M. , Fox Susan H.
Published: September 2006

Investigation of the pathophysiology of psychosis in Parkinson's disease (PD), as well as the assessment of potential novel therapeutics, has been limited by the lack of a well‐validated animal model. MPTP‐lesioned primates exhibit abnormal behaviors that are distinct from dyskinesia and parkinsonism and may represent behavioral correlates of neural processes related to psychosis in PD. Here we assess four types of behavior—agitation, hallucinatory‐like responses to nonapparent stimuli, obsessive grooming, and stereotypies that are termed “psychosis‐like”—and define their pharmacology using a psychosis‐like behavior rating scale. By assessing the actions of drugs known to enhance or attenuate psychosis in PD patients, we find that the pharmacology of these behaviors recapitulates, in several respects, the pharmacology of psychosis in PD. Thus, levodopa and apomorphine elicited psychosis‐like behaviors. Amantadine significantly decreased levodopa‐induced dyskinesia but exacerbated psychosis‐like behaviors. Haloperidol reduced psychosis‐like behaviors but at the expense of increased parkinsonian disability while the atypical neuroleptics clozapine and quetiapine reduced psychosis‐like behaviors without significant effect on parkinsonian disability. The response of different components of the psychotomimetic behavior suggested the involvement of both dopaminergic and nondopaminergic mechanisms in their expression. © 2006 Movement Disorder Society
Polymer–CO2 systems exhibiting retrograde behavior and formation of nanofoams
Authors: Nawaby A Victoria , Handa Y Paul , Liao Xia , Yoshitaka Yamamoto , Tomohiro Mizumoto
Published: September 2006

The sorption of compressed gases in polymers causing a reduction in the glass transition temperature (Tg) is well established. There is, however, limited information on polymer–gas systems with favorable interactions, producing a unique retrograde behavior. This paper reports on using a combination of established techniques of in situ gravimetric and stepwise heat capacity (Cp) measurements using high‐pressure differential scanning calorimetry (DSC) to demonstrate the occurrence of this behavior in acrylonitrile–butadiene–styrene copolymer (ABS)–CO2 and syndiotactic poly(methyl methacrylate) (sPMMA)–CO2 systems. The solubility and diffusion coefficient of CO2 in the range 0 to 65 °C and pressures up to 5.5 MPa were determined, which resulted in a heat of sorption of − 15.5 and − 15 kJ mol−1, and an activation energy for diffusion of 28.3 and 32.1 kJ mol−1 in the two systems, respectively. The fundamental kinetic data and the changes in Cp of the polymer–gas systems were used to determine the plasticization glass transition temperature profile, its relationship to the amount of gas dissolved in the polymer, and hence the formation of nano‐morphologies. Copyright © 2006 Society of Chemical Industry
Impact of spray application methodology on the development of resistance to cypermethrin and spinosad by fall armyworm Spodoptera frugiperda (JE Smith)
Authors: Al‐Sarar Ali , Hall Franklin R , Downer Roger A
Published: September 2006

The development of resistance to an insecticide under various types of application method has yet to be reported in the literature. Five fall armyworm Spodoptera armigera (JE Smith) colonies were reared in a chamber for ten generations before starting topical application bioassays. From each colony, 200–500 third–fourth‐instar larvae were fed for 72 h on corn plants sprayed with cypermethrin or spinosad at minimum application rate (20 g ha−1) using a small droplet size nozzle XR8001VS (volume median diameter Dv0.5 = 163 µm) or a large droplet size nozzle XR8008VS (Dv0.5 = 519 µm). Surviving larvae were transferred to untreated corn leaves to complete their life cycle. Next‐generation third‐instar larvae of each colony were topically dosed with technical cypermethrin or spinosad at 1 µL per larva, and mortality was recorded 24 h post‐treatment. The results indicated that cypermethrin demonstrated an insecticidal activity greater than that of spinosad, and the cypermethrin regression lines moved to the right faster than those for spinosad, indicating an increased tolerance of cypermethrin. Generally, larvae from all generations (F1–F7) under the XR8008VS treatments were less susceptible to cypermethrin and developed resistance faster and to higher levels than larvae from the XR8001VS treatments. The confidence limits (95%) of LD50 for all spinosad treatments indicated that there was no significant difference from the LD50 value of the susceptible reference strain. The results are a first indication that application technology/insecticide reaction may affect the rapidity of resistance development in certain pest/plant scenarios, but field studies are needed to confirm this conclusion. Copyright © 2006 Society of Chemical Industry
Velvetbean (Mucuna pruriens) extracts: impact on Meloidogyne incognita survival and on Lycopersicon esculentum and Lactuca sativa germination and growth
Authors: Zasada Inga A , Klassen Waldemar , Meyer Susan LF , Codallo Maharanie , Abdul‐Baki Aref A
Published: September 2006

Velvetbean (Mucuna spp.) is a summer annual that has been used as a cover crop to reduce erosion, fix nitrogen and suppress weeds and plant‐parasitic nematodes. Crude aqueous extracts (1:15 dry weight plant/volume water) were made from velvetbean plant parts, and various concentrations of the extracts were evaluated in vitro for toxicities to different stages of Meloidogyne incognita (Kofoid and White) Chitwood and for suppression of hypocotyl and root growth and inhibition of germination of tomato (Lycopersicon esculentum L.) and lettuce (Lactuca sativa L.). Germination was only affected by the full‐strength extract from leaf blades. Lettuce root growth was the most sensitive indicator of allelopathic activity of the plant part extracts. Lettuce and tomato root growth was more sensitive to the extract from main roots than to extracts of other plant parts, with lethal concentration (LC50) values of 1.2 and 1.1% respectively. Meloidogyne incognita egg hatch was less sensitive to extracts from velvetbean than the juvenile (J2) stage. There was no difference among LC50 values of the extracts from different plant parts against the egg stage. Based on LC50 values, the extract from fine roots was the least toxic to J2 (LC50 39.9%), and the extract from vines the most toxic (LC50 7.8%). The effects of the extracts were nematicidal because LC50 values did not change when the extracts were removed and replaced with water. Copyright © 2006 Society of Chemical Industry
Real‐time quantitative PCR assays for quantification of L1781 ACCase inhibitor resistance allele in leaf and seed pools of Lolium populations
Authors: Kaundun Shiv S , Cleere Sally M , Stanger Carole P , Burbidge Judith M , Windass John D
Published: September 2006

The I1781L amino acid substitution in the target ACCase enzyme causes broad resistance to ACCase inhibitor herbicides in several monocotyledenous weeds of agronomic importance. This mutation results from a substitution of an adenine (A) residue by either a thymine (T) or cytosine (C) at position 5341 in Alopecurus myosuroides Huds and at an equivalent position in Lolium species, Avena fatua L. and Setaria viridis (L.) Beauv. Two different procedures, the PCR‐based allele‐specific assay (ASA) and the derived cleaved amplified polymorphic sequence (dCAPS) method, have previously been described for detecting this mutation. These methods are, however, only amenable to low sample throughput and are used in the analysis of single plants. Here, an alternative high‐throughput ARMS/Scorpion real‐time quantitative PCR (Q‐PCR) method for measuring levels of the I1781L mutation in pools of leaf and seed samples of Lolium populations is presented. The limit of detection for C and T mutant alleles in a background of wild‐type A is 0.02 and 0.0003% respectively. In this study, DNA from batches of 24 leaf segments measuring 0.5 cm from different plants or 1000 seeds could be conveniently extracted and accurately analysed. As part of assay validation, the comparative analysis of five geographically distinct Lolium populations with dCAPS and Q‐PCR procedures demonstrated the accuracy of the latter method, and the three possible II1781, IL1781 and LL1781 ACCase genotypes being distributed as predicted by the Hardy–Weinberg principle. Given the dominance of the L1781 over the I1781 allele at recommended field rates for most ACCase inhibitors, the frequency of herbicide survivors in the field owing only to the presence of the I1781L mutation is thus predicted to be 2pq + q2, where p and q are the frequencies of the I1781 and L1781 alleles as determined by Q‐PCR. The Q‐PCR assay established allows detection of very low levels of the L1781 ACCase mutation before resistance would normally be discernible in the field. Therefore, it offers the opportunity to tackle resistance at its very onset, potentially avoiding implementation of complicated and often costly weed management practices. Copyright © 2006 Society of Chemical Industry
Insecticide resistance in vector mosquitoes in China
Authors: Cui Feng , Raymond Michel , Qiao Chuan‐Ling
Published: September 2006

Because of their special behaviour, physiology and close relationship with humans, mosquitoes act as one of the most important vectors of human diseases, such as filariasis, Japanese encephalitis, dengue and malaria. The major vector mosquitoes are members of the Culex, Aedes and Anopheles genera. Insecticides play important roles in agricultural production and public health, especially in a country with a huge human population, like China. Large quantities of four classes of insecticides, organochlorines, organophosphates, carbamates and pyrethroids, are applied annually to fields or indoors in China, directly or indirectly bringing heavy selection pressure on vector populations. The seven major species of vector mosquito in China are the Culex pipiens L. complex, C. tritaeniorhynchus Giles, Anopheles sinensis Wied., A. minimus Theobald, A. anthropophagus Xu & Feng, Aedes albopictus (Skuse) and Ae. aegypti L., and all have evolved resistance to all the above types of insecticide except the carbamates. The degree of resistance varies among mosquito species, insecticide classes and regions. This review summarizes the resistance status of these important vector mosquitoes, according to data reported since the 1990s, in order to improve resistance management and epidemic disease control, and to communicate this information from China to the wider community. Copyright © 2006 Society of Chemical Industry
Differential aphicidal effects of chitinase inhibitors on the polyphagous homopteran Myzus persicae (Sulzer)
Authors: Saguez Julien , Dubois Françoise , Vincent Charles , Laberche Jean‐Claude , Sangwan‐Norreel Brigitte S , Giordanengo Philippe
Published: September 2006

Four chitinase inhibitors, cyclo‐(Proline‐Tyrosine), cyclo‐(Histidine‐Proline), allosamidin and psammaplin A, were selected for in vitro feeding experiments with the peach‐potato aphid, Myzus persicae (Sulzer), under controlled photoperiod and temperature conditions. Artificial diets were used to provide chitinase inhibitors at 10, 50 and 100 µg mL−1 to M. persicae. Except for cyclo‐(Proline‐Tyrosine), which did not modify aphid demographic parameters, chitinase inhibitors induced differential aphicidal effects on M. persicae. At all doses, cyclo‐(Histidine‐Proline) induced significant effects affecting daily fecundity, intrinsic rate of natural increase (rm) and doubling time of population. When compared with the control diet, allosamidin decreased nymph survival and daily fecundity, increasing the doubling time of population from 1 to 1.5 days. Psammaplin A was the most toxic inhibitor when delivered via artificial diet, as it induced the death of all aphids reared at 50 and 100 µg mL−1. The results demonstrate the potential use of chitinase inhibitors as aphid management tools. Copyright © 2006 Society of Chemical Industry
Solid‐phase synthesis of C‐terminally modified peptides
Authors: Ten Brink Hefziba T. , Meijer Joris T. , Geel Remon V. , Damen Mark , Löwik Dennis W. P. M. , van Hest Jan C. M.
Published: September 2006

In this paper, a straightforward and generic protocol is presented to label the C‐terminus of a peptide with any desired moiety that is functionalized with a primary amine. Amine‐functional molecules included are polymers (useful for hybrid polymers), long alkyl chains (used in peptide amphiphiles and stabilization of peptides), propargyl amine and azido propyl‐amine (desirable for ‘click’ chemistry), dansyl amine (fluorescent labeling of peptides) and crown ethers (peptide switches/hybrids). In the first part of the procedure, the primary amine is attached to an aldehyde‐functional resin via reductive amination. To the secondary amine that is produced, an amino acid sequence is coupled via a standard solid‐phase peptide synthesis protocol. Since one procedure can be applied for any given amine‐functional moiety, a robust method for C‐terminal peptide labeling is obtained. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
A general treatment of three‐dimensional elasticity of quasicrystals by an operator method
Authors: Gao Yang , Zhao Bao‐Sheng
Published: September 2006

By an operator method, the general solution of three‐dimensional elasticity of quasicrystals is given constructively with some displacement functions, and its completeness is proved at the same time. Nonuniqueness and the scope of nonuniqueness of the general solution are also pointed out. The method used in the paper extends work from elasticity to quasicrystals elasticity. As two special cases, two‐dimensional dodecagonal quasicrystal and one‐dimensional hexagonal QCs are considered, and the general solutions based on the operator method are presented. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical transmission through three‐component Thue–Morse multilayers
Authors: Hu Xubo , Yang Xiangbo , Hu Wei , Guo Qi
Published: September 2006

In this paper, we study the transmission properties of the light through the aperiodic multilayers vertically following the three‐component Thue–Morse (3CTM) sequence. On the basis of the electromagnetic wave theory we present a so‐called decomposition‐substitution (DS) method to analyze the characteristics of the transmission directly and concisely. After predicting the transmission properties from the structure by means of the DS method, we then deduce the formulae of propagation matrices and transmission coefficients analytically and obtain the numerical simulations at the same time. The results obtained by three kinds of method accord with each other. It is found that the 3CTM systems possess an interesting tristable transmissive characteristic, which would be useful for designing some optical tristable devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The C–C pair in the vicinity of a bcc Fe bulk vacancy: electronic structure and bonding
Authors: Simonetti S. , Pronsato M. E. , Brizuela G. , Juan A.
Published: September 2006

C–Fe and C–C interactions near a bcc Fe vacancy were analysed using DFT calculations. A cell containing 14 atoms was used to simulate the local environment of the Fe vacancy. Carbon atoms were positioned in their local energy minimum configurations. The most stable positions for the C atoms in the vacancy region were found at about 1.23 Å from the vacancy centre and near the first nearest‐neighbour octahedral sites. Changes in the electronic structure of Fe atoms near a vacancy were analysed. Fe–Fe bonds surrounding the vacancy weaken their bond when the C atoms are present. This bond weakening is a consequence of C–Fe bond formation. The Fe–C interactions occur mainly via Fe 4s orbitals with a lesser participation of Fe 3p orbitals. There is an electron transfer to the C atoms from their Fe nearest neighbours. The C–C interaction was also analysed. For the C–C distance of 1.462 Å, there is a bonding between the C atoms. The C–C interaction is stronger than the C–Fe interactions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational prediction of grain size during rapid laser surface modification of Al–O ceramic
Authors: Samant Anoop N. , Dahotre Narendra B.
Published: September 2006

The aim of this letter is to present a model including the fundamental non‐equilibrium effects to predict the microstructure evolution during the rapid solidification of laser surface modified Al–O ceramic system to understand grain growth and the physical process involved during the treatment. The obtained data is then compared with the actual measurements from micrographs. This approach is novel compared to other work in the similar field which have looked at the process only at the macroscopic level that included the extractions of macroscopic features such as melt depth and width. Such study is important as laser surface modification can be extended to dressing of alumina grinding wheel material, a part of the Al–O ceramic system. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antioxidative and In Vitro hepatoprotective activity of Bupleurum kaoi leaf infusion
Authors: Liu Chu‐Ting , Chuang Pei‐Ting , Wu Ching‐Yi , Weng Yih‐Ming , Chen Wenlung , Tseng Chin‐Yin
Published: September 2006

The roots of Bupleurus spp. have been used in traditional Chinese herbal medicine for curing liver diseases. Although bioactive saikosaponins have been detected in the leaves as well as in the roots, the aerial parts of the plants are discarded as waste. In the present study, a leaf infusion of B. kaoi Liu, Chao et Chuang, an indigenous Bupleurus species in Taiwan, was prepared and the antioxidant properties and in vitro hepatoprotective activity were demonstrated. The results show that the leaf infusion exerted DPPH free radical scavenging activity, inhibitory capacity on superoxide anion formation and superoxide anion scavenging activity. The hepatotoxicity of acetaminophen (APAP) and carbon tetrachloride (CCl4) on the rat liver cells were also decreased by the leaf infusion. Copyright © 2006 John Wiley & Sons, Ltd.
Delamination of multilayer packaging caused by exfoliating cream ingredients
Authors: Ortiz Gustavo , Garrido‐López Álvaro , Tena María Teresa
Published: September 2006

Exfoliating creams were packed in sachets of composite packaging consisting of polyethylene, aluminium and polyester layers stuck together by polyurethane adhesive, and they were kept in an oven at 40°C in order to accelerate the delamination process. The sachets were then delaminated and the resulting layers were analysed. A headspace solid‐phase microextraction mass spectrometry method (HS–SPME–GC–MS) using a 75µm carboxen polydimethylsiloxane fibre was used to identify the compounds migrating from the exfoliating creams through the polyethylene layer to the aluminium interface and suspected to be responsible for packaging delamination. Several volatile compounds used in the cosmetic industry as perfumes, fixing agents and preservatives, such as menthol, dihydromyrcenol and 2‐phenoxyethanol, were detected in the aluminium/polyester delaminated layer. The exfoliating creams were also analysed by HS–SPME–GC–MS. The study of loss of adhesion of the laminated material exposed to the exfoliating products revealed that the product with a higher concentration of 2‐phenoxyethanol caused a faster decrease in adhesion strength, but the lower adhesion values were found in products with higher concentrations of menthol and dihydromyrcenol. The results obtained showed that the analytical method used was suitable for identifying volatile compounds that migrate through polyethylene to the inner layers of the packaging of exfoliating products, as well as for providing prior information on which products may be difficult to package in sachets. Copyright © 2006 John Wiley & Sons, Ltd.
Simultaneous quantitative analysis of the antimalarials pyrimethamine and sulfamethoxypyrazine in plasma samples using liquid chromatography/tandem mass spectrometry
Authors: Storme Michael L. , Jansen F. Herwig , Goeteyn Wim , Van Bocxlaer Jan F.
Published: September 2006

The work presented here deals with the development of a quantitative tool for the simultaneous determination of sulfamethoxypyrazine (sulfalene)/pyrimethamine in plasma. The chromatography used only takes 12.5 min, allowing a fast sample turnover time. Relative standard deviation of retention times was never above 3.48% (n=66). Adequate sample clean‐up was achieved by a simple and relatively fast liquid/liquid extraction. In this way, ionisation suppression effects, typical for more simple sample clean‐up procedures, could be avoided resulting in absolute plasma effects of maximum –17.1% for sulfalene, –16.1 for the internal standard (IS), and 12% for pyrimethamine. For both pyrimethamine and sulfalene, quadratic calibration curves from 0.00101 to 0.807 µg/mL for pyrimethamine and from 0.271 to 216 µg/mL for sulfalene gave the best fit. Mean coefficients of determination (R2) were 0.9951 (n=6, CV% 0.39) for pyrimethamine and 0.9942 (n=6, CV% 0.13) for sulfalene. Precision was below 9.35% for pyrimethamine and 13.9% for sulfalene. Inaccuracy remained below 15% at all cases. The optimised method was used for a time‐course study of the sulfalene/pyrimethamine combination concentration in plasma of patients treated with Co‐Arinate®, a new curative antimalaria‐medicine. Copyright © 2006 John Wiley & Sons, Ltd.
Prenatal ultrasonographic prediction of the umbilical coiling index at birth and adverse pregnancy outcome
Authors: De Laat M. W. M. , Franx A. , Nikkels P. G. J. , Visser G. H. A.
Published: September 2006

Objectives

To evaluate whether the antenatal umbilical coiling index (aUCI) as measured by ultrasonography predicts the postnatal umbilical coiling index (pUCI) and adverse pregnancy outcome.

Methods

In a prospective study in 117 pregnancies, the aUCI was measured between 28 weeks and term by ultrasonography. The aUCI was calculated as the reciprocal value of the mean pitch of one complete coil. The pUCI was calculated as the number of coils divided by the cord length in cm. The correlation between aUCI and pUCI was assessed and likelihood ratios for adverse pregnancy outcome were calculated.

Results

We had complete data on 81 subjects. Mean aUCI ± SD was 0.30 ± 0.09 and mean pUCI ± SD was 0.17 ± 0.08. The correlation coefficient between aUCI and pUCI was 0.66, P < 0.001. Limits of agreement were 0–0.28 coils/cm. The positive likelihood ratio for small‐for‐gestational‐age infants was 2.6 (95% confidence interval (CI) 0.6–11.6) for ultrasound hypocoiling, and 5.7 (95% CI 1.3–24.8) for ultrasound hypercoiling. The positive likelihood ratio for interventional delivery for non‐reassuring fetal status was 1.2 (95% CI 0.2–9.0) for ultrasound hypocoiling, and 10.3 (95% CI 2.1–50.2) for ultrasound hypercoiling.

Conclusions

Strong correlation coefficients comparing the aUCI and pUCI do not reflect agreement. Since the limits of agreement were almost as wide as the full range for the pUCI, the aUCI does not predict the pUCI with sufficient precision. Larger prospective studies are required to confirm the predictive potential of the aUCI for adverse pregnancy outcome. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Determining chorionicity in twin gestations: three‐dimensional (3D) multiplanar sonographic measurement of intra‐amniotic membrane thickness
Authors: Senat M.‐V. , Quarello E. , Levaillant J. M. , Buonumano A. , Boulvain M. , Frydman R.
Published: September 2006

Objectives

Measuring the thickness of the membranes to determine chorionicity in twins using two‐dimensional (2D) ultrasound may provide uncertain results, given the possibility of measuring in an oblique view. We aimed to determine whether chorionicity can be assessed during the second and third trimesters by measuring the thickness of the membranes with three‐dimensional (3D) multiplanar ultrasound, which ensures the measurement is perpendicular to the membranes, and to evaluate the reproducibility of the technique.

Methods

This was a prospective study of 84 twin pregnancies (30 monochorionic and 54 dichorionic) between 20 and 35 weeks of gestation. The dividing membranes between the fetuses were visualized with 2D and 3D transabdominal sonography and the thickness of the membranes was measured by the multiplanar technique. Intraobserver variability was assessed by comparing the measurements obtained in sagittal and axial views by the same observer. We examined the frequency distributions to determine the optimal cut‐off point of the thickness of the membranes to predict chorionicity. Kappa index, intraclass correlation coefficients and 95% limits of agreement were calculated to evaluate the inter‐ and intraoperator variability. We also compared membrane‐thickness measurement, during the second and third trimesters, using 2D and 3D ultrasound.

Results

In monochorionic and dichorionic pregnancies, respectively, the mean thickness was 1.42 (SD, 0.31) mm and 2.48 (SD, 0.47) mm. With 3D ultrasound, the intraclass correlation coefficient was 0.99 in all cases. The 95% limits of agreement were all within ±0.2 mm. The best cut‐off for membrane thickness for discriminating monochorionic from dichorionic twinning was 1.8 mm. Using this cut‐off, there were one false‐negative (sensitivity, 97%; 95% CI, 83–99%) and three false‐positive (specificity, 94%; 95% CI, 85–99%) diagnoses of monochorionic twins. Kappa indices for intra‐ and interoperator variability were all above 90%, suggesting almost perfect agreement. Measurements with 2D sonography were less accurate (sensitivity and specificity, 83%).

Conclusion

Prenatal assessment of dividing membranes using 3D multiplanar ultrasound is reproducible and may be a useful alternative method for determining chorionicity in twin pregnancies during the second and third trimesters. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Estimating the angle of attack from blade pressure measurements on the NREL Phase VI rotor using a free wake vortex model: axial conditions
Authors: Sant Tonio , van Kuik Gijs , van Bussel G. J. W.
Published: September 2006

Blade element momentum (BEM) methods are still the most common methods used for predicting the aerodynamic loads during the aeroelastic design of wind turbine blades. However, their accuracy is limited by the availability of reliable aerofoil data. Owing to the 3D nature of the flow over wind turbine blades, the aerofoil characteristics will vary considerably from the 2D aerofoil characteristics, especially at the inboard sections of the blades. Detailed surface pressure measurements on the blade surfaces may be used to derive more realistic aerofoil data. However, in doing so, knowledge of the angle of attack distributions is required. This study presents a method in which a free wake vortex model is used to derive such distributions for the NREL Phase VI wind turbine under different operating conditions. The derived free wake geometry solutions are plotted together with the corresponding wake circulation distribution. These plots provide better insight into how circulation formed at the blades is eventually diffused into the wake. The free wake model is described and its numerical behaviour is examined. Copyright © 2006 John Wiley &Sons, Ltd.
Technical aspects of status and expected future trends for wind power in Denmark
Authors: Akhmatov Vladislav , Rasmussen Carsten , Eriksen Peter Børre , Pedersen Jens
Published: September 2006

The power system of Denmark is characterized by significant incorporation of wind power. Presently, more than 20% of the annual electricity consumption is covered by electricity‐producing wind turbines. The largest increase in grid‐incorporated wind power is expected to come from large (offshore) wind farms operating as large wind power plants with ride‐through solutions, connected to the high‐voltage transmission system and providing ancillary services to the system. In Denmark there are presently two offshore wind farms connected to the transmission system: Horns Rev A (160MW rated power in the western part of the country) and Nysted (165MW rated power at Rødsand in Eastern Denmark). The construction of two more offshore wind farms, totalling 400MW by the years 2008–2010, has been announced. This article presents the status, perspectives and technical challenges for wind power in the power system from the point of view of Energinet.dk, Transmission System Operator of Denmark. Copyright © 2006 John Wiley &Sons, Ltd
Spread of the pinewood nematode vectored by the Japanese pine sawyer: modeling and analytical approaches
Authors: Togashi Katsumi , Shigesada Nanako
Published: September 2006

The pinewood nematode,Bursaphelenchus xylophilus, is the causative agent of pine wilt ofPinus thunbergiiandP. densiflorain Japan. The nematode is vectored by cerambycid beetles of the genusMonochamus. It is inferred to have been introduced from North America early in the 1900s and then to have distributed in China, Korea, and Taiwan. Intensive and/or long‐term studies of pine wilt systems have elucidated the pattern and mechanism of the nematode's spread within a pine stand, dispersal of vector beetles, and spread pattern of pine wilt within a prefecture. The modeling of nematode spread over pine stands, which involves beetle reproduction within a pine stand, has been developing and should elucidate the factors influencing the rate at which the nematode range expands. In this review, we summarize the biologies of the nematode, beetle, and tree, and then characterize the spread of the nematode within a pine stand, locally over pine stands, and regionally over unit administrative districts. Local and regional spreading of the nematode is related primarily to long‐distance dispersal by insect vectors and to the artificial transportation of pine logs infested with the nematode and its vector, respectively.
Upper Devonian and Mississippian foraminiferal and rugose coral zonations of Belgium and northern France: a tool for Eurasian correlations
Authors: POTY EDOUARD , DEVUYST FRANCOIS-XAVIER , HANCE LUC
Published: September 2006

The radiation of early Carboniferous foraminifers and rugose corals following the Devonian–Carboniferous crisis offers the best tool for high-resolution correlations in the Mississippian, together with the conodonts in the Tournaisian, notably in the Namur–Dinant Basin. However, some of the guides are facies-controlled and an integrated approach combining biostratigraphy, sedimentology and sequence stratigraphy is critical to identify delayed entries, potential stratigraphic gaps and to avoid diachronous correlations. The main difficulty is in correlating shallow and deeper water facies at any given time. In existing zonations, the Viséan part of the scheme is always more detailed, reflecting the widespread development of shallow-water platforms in the early Viséan which created conditions more suitable for foraminifers and rugose corals over large areas. In contrast, the Tournaisian zones, less well documented, reflect unfavourable environmental conditions in the lower ramp (Dinant Sedimentation Area) and pervasive dolomitization of the inner ramp (Condroz and Namur Sedimentation Areas). Recent progress in understanding the Belgian early Carboniferous sequence stratigraphy and lithostratigraphy, and revision of the biostratigraphy of the key sections, strongly modify former biostratigraphic interpretations. Improvements mainly concern the latest Devonian, the late Tournaisian and the early Viséan. The late Devonian and the Tournaisian are equated with foraminifer zones DFZ1 to DFZ8 and MFZ1 to MFZ8 respectively. The Viséan correlates with zones MFZ9 to MFZ14. Zone MFZ15 straddles the Viséan–Namurian boundary and Zone MFZ16 is the youngest Mississippian zone. The rugose corals allow the recognition of ten zones, RC0 to RC9, covering the Strunian (late Famennian) to Serpukhovian interval. Discrepancies with former zonations are discussed. The Moliniacian Stage is emended to restore the coincidence between its base and that of the Viséan.
The South African stereospondyl Lydekkerina huxleyi (Tetrapoda, Temnospondyli) from the Lower Triassic of Australia
Authors: WARREN A. A. , DAMIANI R. , YATES A. M.
Published: September 2006

The first tetrapod fossil from the Rewan Formation of the Galilee Basin, central Queensland, Australia, is identified as Lydekkerina huxleyi, a stereospondyl found elsewhere only in the Lystrosaurus Assemblage Zone of South Africa. Apomorphies shared with L. huxleyi are: anterior palatal vacuity with anterodorsal projections from its posterior margin; ventral surface of skull roof with series of thickened ridges (condition unknown in other lydekkerinids); and vomerine shagreen present (possible autapomorphic reversal). Restudy of the only other Australian lydekkerinid, Chomatobatrachus halei, shows it to be distinct from L. huxleyi. The Rewan Formation, undifferentiated in the Galilee Basin, can be correlated with the Rewan Group of the Bowen Basin, and to the early part of the Lystrosaurus Assemblage Zone of the Karoo Basin, South Africa, which are of Griesbachian age. Varying palaeoenvironments may contribute to the contrasting nature of the Australian and South African faunas.
Late Jurassic–Early Cretaceous intra-arc sedimentation and volcanism linked to plate motion change in northern Japan
Authors: TAKASHIMA REISHI , NISHI HIROSHI , YOSHIDA TAKEYOSHI
Published: September 2006

The Sorachi Group, composed of Upper Jurassic ophiolite and Lower Cretaceous island-arc volcano-sedimentary cover, provides a record of Late Jurassic–Early Cretaceous sedimentation and volcanism in an island-arc setting off the eastern margin of the Asian continent. Stratigraphic changes in the nature and volume of the Sorachi Group volcanic and volcaniclastic rocks reveal four tectonic stages. These stages resulted from changes in the subduction direction of the Pacific oceanic plate. Stage I in the Late Jurassic was characterized by extensive submarine eruptions of tholeiitic basalt from the back-arc basin. Slab roll-back caused rifting and sea-floor spreading in the supra-subduction zone along the active Asian continental margin. Stage II corresponded to the Berriasian and featured localized trachyandesitic volcanism that formed volcanic islands with typical island-arc chemical compositions. At the beginning of this stage, movement of the Pacific oceanic plate shifted from northeastward to northwestward. During Stage III, in the Valanginian, submarine basaltic volcanism was followed by subsidence. The Pacific oceanic plate motion turned clockwise, and the plate boundary between the Asian continent and the Pacific oceanic plate changed from convergent to transform. During Stage IV in the Hauterivian–Barremian, in situ volcanism ceased in the Sorachi–Yezo basin, and the volcanic front migrated west of the Sorachi–Yezo basin.
Proceedings of the Thirty-eighth Meeting of the Agricultural Research Modellers' Group
Authors: CROMPTON L. A. , WHEELER T. R.
Published: September 2006

This group, which is concerned with the applications of mathematics to agricultural science, was formed in 1970 and has since met at approximately yearly intervals in London for one-day meetings. The thirty-eighth meeting of the group, chaired by Professor A. Kassam of the University of Reading, was held in the Kohn Centre at the Royal Society, 6 Carlton House Terrace, London on Friday, 31 March 2006 when the following papers were read.
The design and analysis of multi-phase plant breeding experiments
Authors: SMITH A. B. , LIM P. , CULLIS B. R.
Published: September 2006

Despite the importance of selection for quality characteristics in plant improvement programmes, literature on experimental design and statistical analysis for these traits is scarce. Most quality traits are obtained from multi-phase experiments in which plant varieties are first grown in a field trial then further processed in the laboratory. In the present paper a general mixed model approach for the analysis of multi-phase data is described, with particular emphasis on quality trait data that are often highly unbalanced and involve substantial sources of non-genetic variation and correlation. Also detailed is a new approach for experimental design that employs partial replication in all phases. The motivation for this was the high cost of obtaining quality trait data, thus the need to limit the total number of samples tested, but still allow use of the mixed model analysis. A simulation study is used to show that the combined use of the new designs and mixed model analysis has substantial benefits in terms of the genetic gain from selection.
Output and sustainability of organic ley/arable crop rotations at two sites in northern Scotland
Authors: TAYLOR B. R. , YOUNIE D. , MATHESON S. , COUTTS M. , MAYER C. , WATSON C. A. , WALKER R. L.
Published: September 2006

Trials at Tulloch, Aberdeen (sandy loam soil, 820 mm rainfall) and Woodside, Elgin (light sandy loam, 730 mm) compared organically managed crop rotations containing different proportions of spring oats, swedes, potatoes and grass/clover leys (0·50 and 0·67 of the rotation at Tulloch; 0·38 and 0·50 at Woodside). The trials simulated farm conditions through the use of grazing animals and the recycling of farmyard manure. The rotations at each site gave similar financial outputs. Yields of oats were higher where these were grown after the main ley phase of the rotation than where they were grown later in the rotation (more ears/m2 and grains/ear), but were not significantly higher after a 4-year ley than after a 3-year ley at Tulloch. It was concluded that all of the rotations were agronomically and financially sustainable. Cereal yields showed large year-to-year variations but little indication of a progressive decline. There were only small changes in soil organic matter, soil P and soil K. Increased early summer weed cover in the arable crops was not matched by increases in weed invasion in the grass/clover leys and did not appear to be affecting yields.
Effect of morphodynamics on the spatial and temporal variation of macrofauna on three sandy beaches, Rio de Janeiro State, Brazil
Authors: Veloso Valéria Gomes , Cardoso Ricardo Silva
Published: September 2006

Three exposed sandy beaches were selected to compare fluctuations in density of the most abundant species, and to verify the influence of spatial and temporal variations on the community structure. Sampling was carried out every three months, from June 1993 to May 1995, on Fora, Prainha, and Boqueirão Beaches. The first two beaches were classified by Dean's morphodynamic index (Ω) as intermediate, and the last as reflective. Slope, beach width and median grain size were significantly different among the beaches. Two-way analysis of variance revealed significant differences in species richness only among the beaches. No significant differences in density of the macrofauna between beaches and season were observed. However, Prainha Beach showed a higher temporal variation of the density of the macrofauna (and higher standard deviation) than the other two beaches. Emerita brasiliensis (Crustacea: Decapoda), Excirolana braziliensis (Crustacea: Isopoda), and Pseudorchestoidea brasiliensis (Crustacea: Amphipoda) were the most abundant species. Canonical correspondence analysis calculated the influence of the temporal variation as 27·5%; the influence of the environmental variation on community structure was 20·9%. The results suggest that in spite of the long-term fluctuations in species density, the beaches did not have temporal differences in the species richness and total density macrofauna during the study period.
New symbiotic associations involving Syllidae (Annelida: Polychaeta), with taxonomic and biological remarks on Pionosyllis magnifica and Syllis cf. armillaris
Authors: López Eduardo , Britayev Temir A. , Martin Daniel , San Martín Guillermo
Published: September 2006

Several new symbiotic associations involving Syllidae (Annelida: Polychaeta) are reported. The number of known host sponge species infested by Haplosyllis spongicola is updated to 36, with seven hosts being reported for the first time (i.e. Aplysina corrugata, Aplysina sp., Cliona sp., Cliona viridis, Phorbas tenacior, one sponge from Iran, one sponge from Cambodia). Two infestation patterns (a few worms per host cm3 in temperate waters and 10s or 100s in tropical waters) are identified. The taxonomic and ecological characteristics of the species are discussed. Five associations occurring between four syllid worms and decapod crustaceans are fully reported for the first time. Syllis cf. armillaris, S.ferrani and S.pontxioi occurred inside gastropod shells occupied by hermit crabs as well as Pionosyllis magnifica, which was also found inside the branchial chambers of the giant crab Paralithodes camtschatica. The description of Pionosyllis magnifica is emended on the basis of the new specimens found, while some taxonomic remarks on Syllis cf. armillaris are given. In addition, further evidence of sexual (P.magnifica) and asexual (S. cf. armillaris) reproduction in symbiotic syllids is provided.
Diversity and distribution of crustaceans from 13 sheltered sandy beaches along São Sebastião Channel, south-eastern Brazil
Authors: Nucci P.R. , Turra A. , Morgado E.H.
Published: September 2006

The crustacean species composition in the intertidal zones of 13 sheltered unconsolidated marine beaches in south-eastern Brazil is described. Fifty-three crustacean species were collected, adding 46 species to the total reported by previous studies in the same region. Decapods dominated the community, in contrast to exposed sandy beaches where peracarids normally predominate. The species were distributed irregularly among the beaches. Richness varied markedly among sites, and was positively related to a combination of factors such as fine sand grains, high organic matter content, and relatively low silt–clay content. The presence of rock fragments enabled both rocky shore and sandy beach crustaceans to occur on the same beaches. Richness and abundance of crustaceans showed no clear relationship to sediment grain size and slope, in contrast to the norm for exposed sandy beaches. The dominance of the tanaid Kalliapseudes schubarti in some areas may be a result of organic matter pollution in the region. These beaches showed higher species richness than typical sheltered and exposed sandy beaches, indicating that this sheltered, highly heterogeneous seascape is an important area for conservation.
The accuracy of density standardization of infaunal benthos
Authors: De Grave S. , Casey D. , Whitaker A.
Published: September 2006

In benthic intertidal studies it is common to standardize species density, and other variables, to a square metre, regardless of the surface area sampled. Using a fully-nested sampling design, with sampling unit surface areas ranging from 0·020 to 1 m2, the present study investigated the effect of this procedure on the accuracy of the results. It is demonstrated that this standardization has a profound influence on the resultant estimates, introducing a substantial error into inter-study comparisons.
The ibex Capra pyrenaica returns to its former Portuguese range
Authors: Moço Gisela , Guerreiro Margarida , Ferreira Ana Filipa , Rebelo António , Loureiro Armando , Petrucci-Fonseca Francisco , Pérez Jesús Ma
Published: September 2006

The ibex Capra pyrenaica has recently recolonized its former Portuguese range from a contiguous Spanish protected area. The first observations of ibex in Portugal were in Peneda-Gerês National Park in 1998. In 2001 we began a survey to confirm ibex presence in Portuguese territory, and to determine the current status of the species there. There are three ibex nuclei in the general area of the international border, and they are expanding their geographical range with two of the nuclei almost restricted to Portuguese territory. In 2003 the ibex population consisted of a minimum of 75 individuals. Different founder histories have led to distinct age structures in each nucleus, but in general they exhibit the population dynamics typical of a recently reintroduced population with high reproductive potential. Priority conservation actions for this newly established population need to include increased monitoring, and reinforcement of the population with individuals from elsewhere. Effective conservation will require collaboration between staff of both Portuguese and Spanish protected areas and an integrated Spanish-Portuguese conservation plan.
Critically Endangered Arabian leopards Panthera pardus nimr persist in the Jabal Samhan Nature Reserve, Oman
Authors: Spalton James Andrew , al Hikmani Hadi Musalam , Willis David , Said Ali Salim Bait
Published: September 2006

Between 1997 and 2000 a survey of the Arabian subspecies of leopard Panthera pardus nimr was conducted in the little known Jabal Samhan Nature Reserve in southern Oman. Using camera-traps 251 photographic records were obtained of 17 individual leopards; nine females, five males, two adults of unknown sex and one cub. Leopards were usually solitary and trail use and movements suggested large ranges characterized by spatial sharing but little temporal overlap. More active by day than night in undisturbed areas, overall the leopards exhibited two peaks in activity, morning and evening. The survey also provided records of leopard prey species and first records of nine Red List mammal species previously unrecorded in Jabal Samhan. Although people are mostly absent from the Reserve there is some conflict between leopards and shepherds who live outside the Reserve. The numbers and activities of frankincense harvesters in the Reserve need to be managed to safeguard the leopard and its habitat. The main challenge for the future is to find ways whereby local communities can benefit from the presence of the Reserve and from the leopards that the Reserve seeks to safeguard.