bluuebunny/crossref_metadata_2025 huggingface dataset:
What can Raman spectroscopy and spectroscopic ellipsometry bring for the characterisation of thin films and materials surface?
Authors: Lewandowska Renata , Gaillet Mélanie , Le Bourdon Gwénaëlle , Eypert Céline , Morel Sophie , Naudin Coralie , Stchakovsky Michel
Published: February 2008

Ellipsometry and Raman spectroscopy offer a wide range of applications for the characterisation of thin films, material surfaces and interfaces. Both analytical methods are non‐contact, non‐destructive and do not require any sample preparation. Firstly, theoretical basics of both techniques will be presented, and then some examples will be described. Copyright © 2008 John Wiley & Sons, Ltd.
Estimation of fetal weight by measurement of fetal thigh soft‐tissue thickness in the late third trimester
Authors: Scioscia M. , Scioscia F. , Vimercati A. , Caradonna F. , Nardelli C. , Pinto L. R. , Selvaggi L. E.
Published: February 2008

Objective

The accuracy of current formulae for the sonographic estimation of fetal weight (EFW) is compromised by significant intra‐ and interobserver variability of biometrical measurements, particularly circumferences. The aim of this study was to assess the reliability of the linear measurement of mid‐thigh soft‐tissue thickness (STT) and to derive a novel formula for EFW.

Methods

This was a prospective study involving 388 singleton uncomplicated pregnancies. There were three consecutive phases: (1) to verify the relationship between STT and birth weight, (2) to derive a novel formula for EFW using femur length and STT only, and (3) to test the accuracy of the new equation. Only the 290 patients who delivered within 48 h of measurement were considered for the analysis. A comparison with other formulae was performed.

Results

STT was significantly correlated with both abdominal circumference and birth weight (r2 = 0.36 and 0.46, respectively; P < 0.001). Both intra‐ and interobserver variability were satisfactory (0.44 ± 0.27 and 0.57 ± 0.35 mm, respectively). The equation for EFW was developed using multiple stepwise regression analysis (EFW = − 1687.47 + (54.1 × femur length) + (76.68 × STT)) and tested prospectively on 69 patients. The new formula yielded results (r = 0.79) that were slightly better in accuracy than two other published equations, and had an absolute mean error of < 15% in 97% of cases.

Conclusions

Our findings confirm the potential of the linear measurement of mid‐thigh STT as a valuable parameter for the sonographic assessment of fetal growth and EFW. Our new equation is apparently at least as reliable as the most widely used formulae for EFW. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Ductus venosus Doppler in fetuses with cardiac defects and increased nuchal translucency thickness
Authors: Maiz N. , Plasencia W. , Dagklis T. , Faros E. , Nicolaides K.
Published: February 2008

Objective

To examine the possible role of Doppler ultrasound assessment of ductus venosus blood flow in screening for major cardiac defects in chromosomally normal fetuses with increased nuchal translucency (NT) thickness at 11 + 0 to 13 + 6 weeks' gestation.

Methods

Ductus venosus blood flow velocity waveforms were obtained immediately before chorionic villus sampling for fetal karyotyping in fetuses with NT thickness of 3.5 mm or more at 11 + 0 to 13 + 6 weeks of gestation. In the chromosomally normal group fetal echocardiography was performed by a specialist pediatric cardiologist at 11 + 0 to 13 + 6 weeks and/or 18–22 weeks' gestation.

Results

Major cardiac defects were diagnosed in 16 (8.4%) of the 191 chromosomally normal fetuses. Reversed or absent flow in the ductus venosus during atrial contraction was observed in 11 of the 16 (68.8%) fetuses with cardiac defects and in 40 of the 175 (22.9%) with no cardiac defects. Multivariate analysis demonstrated that the prevalence of an abnormal A‐wave in the ductus venosus in fetuses without major cardiac defects increased with fetal NT thickness (odds ratio (OR), 1.463; 95% CI, 1.183–1.809; P < 0.0001) but in those with cardiac defects it did not change significantly with NT thickness (OR, 2.054; 95% CI, 0.573–7.360; P = 0.269). The likelihood ratio for a major cardiac defect when the ductus venosus flow was abnormal decreased with fetal NT thickness from 4.58 at NT 3.5 mm to 2.47 for NT 5.5 mm, and the likelihood ratio when the ductus venosus flow was normal increased from 0.37 at NT 3.5 mm to 0.43 for NT 5.5 mm.

Conclusion

In chromosomally normal fetuses with increased NT the finding of an absent or reversed A‐wave in the ductus venosus is associated with a three‐fold increase in the likelihood of a major cardiac defect, whereas the finding of normal ductal flow is associated with a halving in risk for such defects. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Outcome of antenatally diagnosed cardiac rhabdomyoma: case series and a meta‐analysis
Authors: Chao A. S. , Chao A. , Wang T. H. , Chang Y. C. , Chang Y. L. , Hsieh C. C. , Lien R. , Su W. J.
Published: February 2008

Objectives

Rhabdomyoma, the most common primary fetal cardiac tumor, is often associated with tuberous sclerosis (TS). We aimed to evaluate outcome in cases diagnosed with fetal cardiac rhabdomyoma.

Methods

This study presents 11 cases with fetal cardiac rhabdomyoma. In addition, all relevant published cases of antenatally diagnosed cardiac rhabdomyoma since 1982 were identified from MEDLINE. We evaluated the following risk factors associated with clinical impact and perinatal outcome: family history of TS, gestational age at diagnosis, tumor size, site and number of tumors, tumor progression, and associated intracardiac and extracardiac anomalies.

Results

In this meta‐analysis, 138 cases, including nine newly added by us, were categorized into Group A (107 live babies) and Group B (16 neonatal deaths and 15 intrauterine fetal deaths). Univariate analysis showed that large cardiac tumors (P < 0.0001), fetal dysrhythmia (P < 0.0001) and hydrops (P < 0.0001) were strong predictors of neonatal outcome. Tumor size ≥ 20 mm (relative risk (RR), 20.6; 95% CI, 2.2–195.9; P = 0.009) and fetal dysrhythmia (RR, 13.6; 95% CI, 2.9–62.3; P = 0.001) were significantly associated with neonatal morbidity. TS, present in 85/133 (63.9%) cases, was significantly associated with multiple cardiac tumors (P < 0.0001) and family history of TS (P = 0.02).

Conclusions

Large tumor size and hydrops are significantly associated with poor neonatal outcome, whereas family history of TS and multiple fetal cardiac tumors are associated with TS. Any sonographic detection of a fetal cardiac tumor should warrant further investigation for the possible presence of associated disorders. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Comparison of the learning curves of digital examination and transabdominal sonography for the determination of fetal head position during labor
Authors: Rozenberg P. , Porcher R. , Salomon L. J. , Boirot F. , Morin C. , Ville Y.
Published: February 2008

Objectives

To evaluate the learning curve of transabdominal sonography for the determination of fetal head position in labor and to compare it with that of digital vaginal examination.

Methods

A student midwife who had never performed digital vaginal examination or ultrasound examination was recruited for this study. Instructions on how to perform digital vaginal examination and ultrasound examination were given before and after completing the first vaginal and ultrasound examinations, and repeated for each subsequent examination for as long as necessary. Digital and ultrasound diagnoses of the fetal head position were always performed first by the student midwife, and repeated by an experienced midwife or physician. The learning curve for identification of the fetal head position by either one of the two methods was analyzed using the cumulative sums (CUSUM) method for measurement errors.

Results

One hundred patients underwent digital vaginal examination and 99 had transabdominal sonography for the determination of fetal head position. An error rate of around 50% for vaginal examination was nearly constant during the first 50 examinations. It decreased subsequently, to stabilize at a low level from the 82nd patient. Errors of ± 180° were the most frequent. The learning curve for ultrasound imaging stabilized earlier than that of vaginal examination, after the 32nd patient. The most frequent errors with ultrasound examination were the inability to conclude on a diagnosis, particularly at the beginning of training, followed by errors of ± 45°.

Conclusions

Based on our findings for the student tested, learning and accuracy of the determination of fetal head position in labor were easier and higher, respectively, with transabdominal sonography than with digital examination. This should encourage physicians to introduce clinical ultrasound examination into their practice. CUSUM charts provide a reliable representation of the learning curve, by accumulating evidence of performance. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Round ligament varices: sonographic appearance in pregnancy
Authors: McKenna D. A. , Carter J. T. , Poder L. , Gosnell J. E. , Maa J. , Pearl J. M. , Goldstein R. B.
Published: February 2008

Round ligament varices (RLV) are an important clinical entity as they may cause hernia‐like symptoms in the absence of a true hernia. When this condition is diagnosed correctly, unnecessary intervention may be prevented. We aimed to determine the significance and anatomy of RLV in pregnancy and to review and describe their clinical and sonographic appearance. We followed prospectively five patients who presented during pregnancy with clinical symptoms suspicious of an inguinal hernia. All patients were diagnosed with RLV on ultrasound examination. All patients were managed conservatively and in all five cases, RLV resolved spontaneously postpartum. The diagnosis of RLV should be considered in pregnant women presenting with a groin mass. Sonography is diagnostic and can save unnecessary surgical exploration and associated morbidity. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Transposition of the great arteries in the fetus: assessment of the spatial relationships of the arterial trunks by four‐dimensional echocardiography
Authors: Paladini D. , Volpe P. , Sglavo G. , Vassallo M. , De Robertis V. , Marasini M. , Russo M. G.
Published: February 2008

Objective

Coronary arterial abnormalities can be one of the few negative prognostic indicators in transposition of the great arteries (TGA), and their occurrence is related to the type of spatial relationship of the great arteries. The main objective of this study was to assess whether the use of the reconstructed en‐face view with color Doppler imaging of the four cardiac valves can demonstrate the different types of spatial relationship of the arterial trunks in fetuses with TGA, in order to derive the risk of coronary abnormalities. A secondary end‐point was the evaluation of the type of coronary arterial branching pattern.

Methods

Twenty‐three fetuses with a confirmed diagnosis of TGA underwent four‐dimensional (4D) echocardiography at 19–33 gestational weeks. The en‐face view of the four cardiac valves and color Doppler with high persistence were employed to assess the spatial relationships of the great arteries. In all cases, confirmation of the vessels' arrangement and coronary arterial distribution was obtained at neonatal echocardiography and/or surgery.

Results

The spatial relationships of the great vessels was identified correctly in 20/23 (87%) cases. The aorta was found to be located anterior to and to the right of the pulmonary trunk in 13/23 (56.5%) cases and just anterior to the pulmonary artery in 6/23 (26.1%) cases; in the remaining four (17.4%) cases, the two vessels were side by side. With respect to the association between the spatial relationship of the great arteries and the occurrence of an unusual pattern of coronary arterial branching, five of the TGA fetuses had abnormal coronary arterial distribution.

Conclusions

Using 4D echocardiography with color Doppler, it is possible to define the spatial relationships of the great arteries in fetuses with TGA with a high degree of accuracy. This information can be used during counseling to predict the likelihood of abnormal coronary arterial distribution. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Nuclear microprobe studies of elemental distribution in mycorrhizal and non‐mycorrhizal roots of Ni‐hyperaccumulator Berkheya coddii
Authors: Orłowska E. , Mesjasz‐Przybyłowicz J. , Przybyłowicz W. , Turnau K.
Published: February 2008

Micro–particle‐induced x‐ray emission (PIXE) was used to assess the influence of arbuscular mycorrhiza on the elemental concentration and distribution in roots of Berkheya coddii and to evaluate the role of fungal hyphae in elemental uptake by this plant. Analysis revealed a significant influence of mycorrhiza on the concentration and distribution of elements in roots of B. coddii. Mycorrhizal roots had significantly higher concentration of P, Ca, Zn and Cu than the non‐mycorrhizal ones. The mycorrhizal fungi also affected the distribution of elements (P, K, Cl, Zn and Ni) within the roots. The external fungal hyphae showed a high binding capacity of metals (Cu, Zn, and Ni). Matrix corrections done on the basis of simultaneous use of proton backscattering technique were essential due to the highly variable thickness of analyzed specimens. Copyright © 2008 John Wiley & Sons, Ltd.
Micro‐PIXE determination of Zr in rutile: an application to geothermometry of high‐P rocks from the western Alps (Italy)
Authors: Vaggelli Gloria , Borghi Alessandro , Calusi Silvia , Cossio Roberto , Giuntini Lorenzo , Massi Mirko
Published: February 2008

The Western Alps of Northern Italy mostly consist of lithotectonic units which re‐crystallised and were metamorphosed at high depth in a subduction zone. During their exhumation to shallow crustal levels, however, the high‐pressure (high‐P) mineral assemblages were pervasively re‐equilibrated under low‐pressure (low‐P) conditions, making difficult to estimate the metamorphic thermal peak.

Rutile [TiO2] is a typical high‐P mineral, occurring as relict phase in low‐P re‐equilibrated metamorphic rocks. Recent studies suggest that, in thermodynamic systems buffered by the occurrence of quartz and zircon in the rock, Zr content in rutile is a temperature–dependent function that can be modelled quantitatively.

An application of rutile Zr‐geothermometer to continental and oceanic rocks of the Western Alps, pervasively re‐equilibrated under low‐P conditions, is presented.

The selected rutile crystals were analysed by PIXE using a microbeam set‐up at the LABEC laboratory of INFN in Florence. The PIXE spectra and maps were processed by Geopixe software package. Micro‐PIXE analyses allowed determining the concentration and the distribution of Zr.

Results obtained by applying the rutile Zr‐geothermometer gave a more precise indication about the temperatures of the metamorphic conditions suffered by Alpine metamorphic rocks with respect to phase relations and conventional geothermometry, showing that determination of Zr concentration by micro‐PIXE technique is a useful tool to reconstruct metamorphic events.

The continental units, outcropping in separate zones of Western Alps, show two slightly different thermal peaks (Tmean = 530 ± 10 °C and Tmean = 555 ± 10 °C) for the same metamorphic event. The oceanic units provide Tmean estimates of 575 ± 10 °C slightly higher than the continental units. Copyright © 2008 John Wiley & Sons, Ltd.
Effects due to Popocatepetl volcano eruptions on the elemental concentrations in tree growth rings
Authors: Cruz‐Muñoz A. R. , Rodríguez‐Fernández L. , Calva‐Vázquez G. , Ruvalcaba‐Sil J. L.
Published: February 2008

The Popocatepetl volcano has increased its activity since the 1991 affecting the environmental conditions of its surroundings. The concentration of Z > 12 elements were measured on pine tree rings from forests in Paso de Cortés, located at 6 km from the volcano's crater. The analysis was done by simultaneous PIXE‐RBS using an external proton beam on tree rings of Pinus montezumae. In order to understand the effects originated by eruptions in those near forests this study provides information about the elemental concentration in pines of this region during the years from 1974 to 2004. The tree rings composition exhibit an increment tendency for P, S and K concentrations since 1991. The metallic elements Mn, Fe and Cu do not present significant variations or a clear behavior with the time. These results indicate that changes in the pines elemental compositions are more related to gaseous volcanic exhalations of the Popocatepetl than to its ash emissions. A decrease in the Zn content related to the S increment is observed. The Zn decrement began to be registered around 8 years before the volcano raised its activity and this effect is due to the micronutrients mobility through the tree trunk. From this result it is possible to establish that for dendrochronology studies in pines using elemental minerals with Z > 20, changes in the environment can be comparable only by intervals of 7 to 8 years. Copyright © 2008 John Wiley & Sons, Ltd.
Transmission of raised blood pressure and endothelial dysfunction to the F2generation induced by maternal protein restriction in the F0, in the absence of dietary challenge in the F1generation
Authors: Torrens Christopher , Poston Lucilla , Hanson Mark A.
Published: February 2008

We have previously demonstrated that maternal protein restriction during pregnancy leads to raised blood pressure and endothelial dysfunction in the offspring (F1). Here we show that these characteristics are transmitted to the F2offspring through the maternal line, in the absence of any additional challenges to the F1. Female Wistar rats were fed either a control (18 % casein) or protein-restricted diet (PR; 9 % casein) throughout pregnancy. Female F1offspring, maintained on standard chow postpartum, were mated with breeding males to produce F2progeny. Systolic blood pressure (SBP) in male F2offspring was assessed by tail-cuff plethysmography at age 100 d and vascular function of small mesenteric arteries by wire myography at age 80 and 200 d. SBP was raised in PR F2offspring compared with controls (control 122·1 (sem2·3) mmHg,n7; PR 134·7 (sem3·2) mmHg,n6;P < 0·01) and endothelial function, assessed by vasodilatation to acetylcholine, was impaired at both age 80 d (% maximal response: control 89·7 (sem2·6),n14; PR 72·7 (sem4·4),n15;P < 0·01) and 200 d (effective concentration equal to 50 % of maximum (pEC50): control 7·67 (sem0·10),n10; PR 7·33 (sem0·07),n8;P < 0·05). The present study demonstrates that both raised blood pressure and endothelial dysfunction are passed via the maternal line to grand-offspring in the absence of any additional dietary challenges to their F1mothers. Risk factors for chronic disease may therefore be heritable by non-genomic processes.
Parasitism of the soybean aphid,Aphis glycinesbyBinodoxys communis: the role of aphid defensive behaviour and parasitoid reproductive performance
Authors: Wyckhuys K.A.G. , Stone L. , Desneux N. , Hoelmer K.A. , Hopper K.R. , Heimpel G.E.
Published: February 2008

The Asian parasitoid,Binodoxys communis(Gahan) (Hymenoptera: Braconidae), is a candidate for release against the exotic soybean aphid,Aphis glycinesMatsumura (Hemiptera: Aphididae), in North America. In this study, we examined preferences byB. communisfor the different developmental stages ofA. glycinesand investigated consequences of these preferences for parasitoid fitness. We also determined to what extent aphid defensive behaviours mediate such preferences. We found thatB. communisreadily attacks and successfully develops in the differentA. glycinesdevelopmental stages.Binodoxys communisdevelopment time gradually increased with aphid developmental stage, and wasps took longest to develop in alates. An average (±SE) of 54.01±0.08% of parasitizedA. glycinesalatoid nymphs transformed into winged adult aphids prior to mummification. No-choice assays showed a higher proportion of successful attacks for immature apterousA. glycinesnymphs compared to adults and alatoid nymphs. Also, choice trials indicated avoidance and lower attack and oviposition of adults and alatoid nymphs. The different aphid stages exhibited a range of defensive behaviours, including body raising, kicking and body rotation. These defenses were employed most effectively by larger aphids. We discuss implications for the potential establishment, spread and biological control efficacy ofA. glycinesbyB. communisin the event that it is released in North America.
Multi-stage dehydration–decompression in the metagabbros from the lower crustal rocks of the Serre (southern Calabria, Italy)
Authors: ACQUAFREDDA PASQUALE , FORNELLI ANNAMARIA , PICCARRETA GIUSEPPE , PASCAZIO ANNARITA
Published: February 2008

Porphyroblastic garnet-bearing metagabbros from the base of the lower crust section of the Serre (southern Italy) exhibit multi-stage dehydration and decompression after the Panafrican emplacement of their protoliths. The first dehydration event produced Am–Opx–Cpx–Pl–Grt as the peak assemblage. Two decompression stages are documented by: (1) coronas of Opx–Pl and Opx–Am, and symplectites of Opx–Am–Pl around clinopyroxene within the porphyroblastic garnet as well as in the matrix and (2) symplectites of Pl–Am–Opx–Grt having different textures around the porphyroblastic garnet. During the second decompression stage, a new local, somewhat intense, dehydration occurred and produced rims of Opx+Pl around the porphyroblastic amphibole, or lenses of Pl–Opx–Am–Spl±Bt between layers of dominant amphibole. A deformation stage separates older from younger reaction textures. The porphyroblastic garnet, its inclusions and the matrix are affected by fractures, which have been overgrown by coronas and symplectites around the porphyroblastic garnet and the amphibole of the matrix. PreferredP–Testimates are: ∼900 °C and ∼1.1 GPa at the metamorphic peak; ∼850 °C and 0.8–0.9 GPa during the formation of corona around clinopyroxene; 750–650 °C and 0.7–0.8 GPa during the formation of corona around garnet. All these textures formed under granulite-facies conditions. The subsequent metamorphic evolution consists of rehydration under amphibolite-facies conditions. TheP–T–tpath agrees with the path shown by the uppermost migmatites of the Serre section, and theP–Testimates at the top and the bottom of the section are consistent with the thickness (7–8 km) of the lower crustal segment. A contractional regime, which caused a crustal thickening of about 35 km, was followed by an extensional one producing significant crustal thinning; the change of tectonic regime probably occurred about 300 Ma ago when the emplacement of voluminous granitoids and the initial stages of exhumation of the lower crustal section had taken place.
Observations on the wavenumber spectrum and evolution of an internal wave attractor
Authors: HAZEWINKEL JEROEN , VAN BREEVOORT PIETER , DALZIEL STUART B. , MAAS LEO R. M.
Published: February 2008

Reflecting internal gravity waves in a stratified fluid preserve their frequency and thus their angle with the gravitational direction. At boundaries that are neither horizontal nor vertical, this leads to a focusing or defocusing of the waves. Previous theoretical and experimental work has demonstrated how this can lead to internal wave energy being focused onto ‘wave attractors’ in relatively simple geometries. We present new experimental and theoretical results on the dynamics of wave attractors in a nearly two-dimensional trapezoidal basin. In particular, we demonstrate how a basin-scale mode forced by simple mechanical excitation develops an equilibrium spectrum. We find a balance between focusing of the basin-scale internal wave by reflection from a single sloping boundary and viscous dissipation of the waves with higher wavenumbers. Theoretical predictions using a simple ray-tracing technique are found to agree well with direct experimental observations of the waves. With this we explain the observed behaviour of the wave attractor during the initial development, steady forcing, and the surprising increase of wavenumber during the decay of the wave field after the forcing is terminated.
Structure formation in homogeneous freely decaying rotating turbulence
Authors: STAPLEHURST P. J. , DAVIDSON P. A. , DALZIEL S. B.
Published: February 2008

One of the most striking features of rotating turbulence is the inevitable appearance of large-scale columnar structures. Whilst these structures are frequently observed, the processes by which they are created are still poorly understood. In this paper we consider the emergence of these structures from freely decaying, rotating turbulence with Ro ∼ 1. Our study follows the conjecture by Davidson, Staplehurst & Dalziel (J. Fluid Mech., vol. 557, 2006, p. 135) that the structure formation may be due to linear inertial wave propagation, which was shown to be consistent with the growth of columnar eddies in inhomogeneous turbulence. Here we extend that work and consider the case of homogeneous turbulence.

We describe laboratory experiments where homogeneous turbulence is created in a rotating tank. The turbulence is generated with Ro ∼ 1, and as the energy decays, the formation of columnar vortices is observed. The axial growth of these columnar structures is then measured using two-point correlations and in all cases the results are consistent with structure formation via linear inertial wave propagation. In particular, we obtain a self-similar collapse of the two-point correlations when the axial coordinate is normalized by Ωtb, where b is a measure of the integral scale in the horizontal plane and Ω is the rotation rate. Although our results do not exclude the possibility of significant nonlinear dynamics, they are consistent with the conjecture of Davidson et al. (2006) that linear dynamics play a strong guiding hand in structure formation.
Spiral swimming of an artificial micro-swimmer
Authors: KEAVENY ERIC E. , MAXEY MARTIN R.
Published: February 2008

A device constructed from a filament of paramagnetic beads connected to a human red blood cell will swim when subject to an oscillating magnetic field. Bending waves propagate from the tip of the tail toward the red blood cell in a fashion analogous to flagellum beating, making the artificial swimmer a candidate for studying what has been referred to as ‘flexible oar’ micro-swimming. In this study, we demonstrate that under the influence of a rotating field the artificial swimmer will perform ‘corkscrew’-type swimming. We conduct numerical simulations of the swimmer where the paramagnetic tail is represented as a series of rigid spheres connected by flexible but inextensible links. An optimal range of parameters governing the relative strength of viscous, elastic and magnetic forces is identified for swimming speed. A parameterization of the motion is extracted and examined as a function of the driving frequency. With a continuous elastica/resistive force model, we obtain an expression for the swimming speed in the low-frequency limit. Using this expression we explore further the effects of the applied field, the ratio of the transverse field to the constant field, and the ratio of the radius of the sphere to the length of the filament tail on the resulting dynamics.
Frontal waves in a strait
Authors: STERN MELVIN E. , SIMEONOV JULIAN A.
Published: February 2008

The slow downstream (x) variation of a dense and inviscid bottom current (u) in a parabolic strait with a sill at y = 0 is investigated. Vanishing potential vorticity is assumed and the density interface in the 1 1/2-layer model intersects the bottom at y = y1 and y = y2 < y1, where the vanishing layer thickness (h) provides the free dynamical boundary condition. For time-dependent finite-amplitude waves, the nonlinear hyperbolic equations obtained here give the wave velocity and indicate the sense in which lateral wave steepening occurs. The long-wave perturbations of y1(x,t), y2(x,t) are stationary if

where g′ is the reduced gravity, μ = ∂2M/∂y2 is the parabolic curvature of the bottom elevation (M), and f is the Coriolis parameter. This controls the upstream–downstream flow, and the downstream nonlinearity generates ‘short’ waves which may initiate lateral mixing with the adjacent (less dense) water mass.

It is also shown that short waves are exponentially amplified with a maximum growth rate (about 1/day) depending only on g′μ/f2. When g′μ/f2 = 1 (a narrow strait) the instability is suppressed, but for small g′μ/f2≪1 the growth rate is comparable to the flat bottom case μ = 0, studied by Griffiths, Killworth & Stern (J. Fluid Mech. Vol. 117, 1982, p. 343.).
The elephant mode between two rotating disks
Authors: VIAUD BERTRAND , SERRE ERIC , CHOMAZ JEAN-MARC
Published: February 2008

Spectral direct numerical simulations (DNS) are carried out for a source–sink flow in an annular cavity between two co-rotating disks. When the Reynolds number based on the forced inflow is increased, a self-sustained crossflow instability of finite amplitude is observed. We show that this nonlinear global mode is made up of a front located at the upstream boundary of the absolutely unstable domain, followed by a saturated spiral mode, and that its properties are in good agreement with results of the local stability theory. This structure is characteristic of the so-called elephant mode of Pier & Huerre (J. Fluid Mech. vol. 435, 2001, p. 145). The global bifurcation is subcritical since only large-amplitude initial perturbations are found to trigger the elephant mode. Small-amplitude perturbations induce a long-lasting transient growth but lead eventually to a damped linear global mode, showing that non-parallel effects counteract the absolute instability and restabilize the flow. A similar linear global stabilization due to non-parallel effects has been found in the case of the flow above a single rotating disk. For the single-disk geometry, the existence of an elephant mode would imply, together with results of Davies & Carpenter (2003) a subcritical global instability, which has not yet been demonstrated. Although the present geometry differs from the single-disk case, the existence of a subcritical global bifurcation is now established, allowing a precise analysis of the transition scenarios.
Subsyllabic unit preference in young Chinese children
Authors: WANG MIN , CHENG CHENXI
Published: February 2008

We reported three experiments investigating subsyllabic unit preference in young Chinese children. In Experiment 1, a Chinese sound similarity judgment task was designed in which 48 pair of stimuli varied in terms of shared subsyllabic units (i.e., vowel, body, rime, onset-coda). Grade 1 Chinese-speaking monolingual children judged pairs with shared body units most similar. In Experiment 2, the sound similarity judgment tasks in Chinese and English were tested on a group of Chinese–English bilingual children. Grade 1 children judged shared-body pairs most similar in Chinese and shared-rime pairs most similar in English. In both experiments, preschool children showed a similar pattern of performance to the Grade 1 children in the Chinese task. In Experiment 3, sound matching tasks in Chinese and English were designed. Grade 1 bilingual children again showed a preference for matching body over rime in Chinese, and for matching rime over body in English. Taken together, these results support the hypotheses that the subsyllabic unit preference in Chinese is driven by the spoken language properties, and that there exist cross-language differences in processing spoken syllables.
Serological evidence ofBartonella henselaeinfection in healthy people in Catalonia, Spain
Authors: PONS I. , SANFELIU I. , CARDEÑOSA N. , NOGUERAS M. M. , FONT B. , SEGURA F.
Published: February 2008

Cat scratch disease (CSD), bacillary angiomatosis, hepatic peliosis and some cases of bacteraemia, endocarditis, and osteomyelitis are directly caused by some species of the genusBartonella. The purpose of this study was to determine the prevalence of IgG antibodies againstBartonella henselaein healthy people and to identify the epidemiological factors involved. Serum samples from 218 patients were examined by indirect immunofluorescence assay (IFA). Significance levels for univariate statistical analysis were determined by the Mann–WhitneyUtest, χ2test and Fisher's exact test. Of 218 patients, 99 were female and 119 male, with a median age of 34·36 years (range 0–91 years). Nineteen (8·7%) reacted withB. henselaeantigens. Of all the factors concerning the seroprevalence rate being studied (age, sex, contact with animals, residential area), only age was statistically significant. Our serological data seems to indicate thatB. henselaeis present in Catalonia and could be transmitted to humans.
Social Sciences: Truthful or Useful?
Authors: Drenth Pieter J. D.
Published: February 2008

The theme of the 2006 IAP Conference, held at Alexandria, from 1–3 December 2006, was ‘The Unity of Science’. Let me explain how I interpret this interesting motto. For me, this does not mean that there is one regina scientiarum that rules over the other fields of science and learning; a role that was allotted to theology in olden times, and that nowadays – in a more secular vein – is claimed by physics. In my view, the notion ‘unity of science’ rather refers to ‘communality within diversity’. Disciplines vary in content, issues and methods. But there are also quite some common objectives, interests and concerns, the most important of which may be the common goal of searching for testable truth with objective and independent evidence. The communalities render it possible, or even imperative, to communicate and to cooperate. The diversity implies complementariness and calls for interdisciplinarity in the study of today’s numerous and complex phenomena in science and society.
Solidarność, the Western World, and the End of the Cold War
Authors: Goddeeris Idesbald
Published: February 2008

It is not unusual to credit certain individuals with having put and end to the Cold War. This essay discusses some of the most important of these people, focusing on their role in the Polish crisis of 1980–82: Mikhail Gorbachev, John Paul II, Ronald Reagan, and Lane Kirkland. The author arrives at the conclusion that the question of the extent to which individuals can be held responsible for the victory over the Soviet Union is wrong, because it neglects underlying processes, such as the economic crisis in the Eastern Bloc and East–West contacts established during the détente of the 1970s.
Financial relevance of organic farming payments for Western and Eastern European organic farms
Authors: Zander K. , Nieberg H. , Offermann F.
Published: February 2008

Organic farming in the European Union has been supported widely since 1994. Against the background of discussions concerning the design and level of organic farming support, and the relevance of organic payments for the economic success of organic farms, the question emerges as to the impact of support payments on the sustainable development of organic farming in Europe. Different databases and methodological approaches have been chosen to demonstrate the role of organic farming payments for the viability of organic farms for selected Western and Eastern European study countries. Economic analyses are based on national Farm Accountancy Data Network (FADN) in the Western European countries and on ‘typical farms’ in the Eastern European group. As a supplement to the modeling analyses, a detailed survey of 50 organic farms was carried out in each of the study countries. Organic farming payments were assessed to be ‘important’ or ‘very important’ to the economic situation on farms by the majority of the farmers surveyed. The outcome of the economic analyses shows that organic farming payments contribute on average 4–6% of gross output in the Western European countries and 4–19% in the Eastern European countries studied. The results put the level of specific support for organic farming into perspective, as other support payments and market returns contribute larger shares of total farm revenue in all the countries analyzed. Organic farming payments account for 10–30% of family farm income plus wages in Western European study countries and—after EU accession—up to three-quarters in some of the Eastern European countries, thus highlighting the considerable vulnerability of organic farms to changes in organic farming policy. As a general trend in both the West and the East, it can be observed that the policy dependency of farms has increased over recent years. Changes in organic area support, which are actually under discussion in some countries, must be carried out with a sense of proportion, since support payments will continue to play an important role in the profitability of organic farms. Nevertheless, in order to reduce dependency on area payments, organic farming support should follow an integrated approach, using a mix of support measures including, e.g., the improvement of processing and marketing facilities, support for farm cooperation and activities designed to enhance demand.
Indirekte Kommunikation durch Zitierungen und Referenzen in der Psychologie
Authors: Krampen Günter , Becker Ralf , Montada Leo
Published: February 2008

Zusammenfassung. Inhaltsanalytische Befunde zu Häufigkeiten und Arten der indirekten Kommunikation innerhalb der Psychologie durch das Zitieren anderer Autoren in monographisch versus editorisch verfassten Lehrbüchern, Enzyklopädien und Testmanualen werden dargestellt. Wegen der wachsenden Bedeutung von Zitationshäufigkeiten für die Produktivitätsbewertung von Wissenschaftlern und Hochschulinstituten sowie für historiographische Analysen wurde empirisch ermittelt, was wie häufig und in welcher Form in der deutschsprachigen Psychologie zitiert wird. Für eine nach sechs psychologischen Teildisziplinen (Sozial-, Entwicklungs-, Persönlichkeits-, Biologische, Pädagogische und Klinische Psychologie) sowie die genannten Literaturgattungen geschichtete Zufallsstichprobe von 28 Publikationen wurden Literaturangaben nach der Publikationssprache der zitierten Quellen, der Anzahl der Fremd- versus Selbstreferenzen, der Gattung der zitierten Literatur und der Zitierungsarten im Text untersucht. Die Ergebnisse zeigen, dass (1) über 50% der Literaturangaben Zeitschriftenbeiträge, 10%-20% Monographien und 10%-20% Buchbeiträge sind, (2) Selbstreferenzen der Autoren etwa 10% der Literaturangaben ausmachen, (3) englischsprachige Literaturangaben mit über 60% dominieren, (4) in gut 70% der Zitationen deutliche Bezüge zu Theorien, Methoden oder Befunden aus den Quellen hergestellt werden, (5) etwa 25% der Zitierungen vage, global, flüchtig oder oberflächlich bleiben, (6) mit knapp 3% selten wörtlich zitiert wird und (7) kritische Auseinandersetzungen mit zitierten Arbeiten mit 2% der Zitierungen sehr selten sind. Sowohl in den Gesamtzahlen der Literaturangaben und Zitierungen im Text als auch in den Zitierungsarten zeigen sich nur geringe Unterschiede zwischen den psychologischen Teildisziplinen. Dieses Befundmuster stimmt mit dem einer früheren Inhaltsanalyse der Zitierungshäufigkeiten und -arten in deutsch- versus englischsprachigen Zeitschriftenbeiträgen überein und belegt für die indirekte wissenschaftliche Kommunikation in der Psychologie relativ stark ausgeprägte Gemeinsamkeiten und Normierungen. Die Implikationen der Befunde für die Repräsentativität und Validität von Zitations-Datenbanken für Evaluationszwecke werden diskutiert.
Impact of the Number of Response Categories on Linearity and Sensitivity of Self-Anchoring Scales
Authors: Hofmans Joeri , Theuns Peter , Mairesse Olivier
Published: February 2008

Abstract. In this research, the relationship between the number of response categories and the linearity and sensitivity of self-anchoring scales is tested. According to the functional measurement paradigm, people integrate their impressions of stimuli using simple algebraic models. Then the integrated stimulus is transformed into an overt response on a rating scale. The combination of a particular algebraic integration rule along with a linear rating scale predicts specific patterns in a factorial plot. In two functional measurement experiments we manipulated the number of categories of different self-anchoring scales and attempted to replicate a specific pattern based on the integration rules found in previous research. For both experiments, the predicted pattern was observed for all scales. This indicates that the number of response categories does not impact on the linearity of the scale. Moreover, there is no relationship between the number of response categories and the sensitivity of the scale as measured by the F ratio for the main effects.
Geomorphology of the southernmost Longitudinal Valley fault: Implications for evolution of the active suture of eastern Taiwan
Authors: Shyu J. Bruce H. , Sieh Kerry , Chen Yue‐Gau , Chuang Ray Y. , Wang Yu , Chung Ling‐Ho
Published: February 2008

In order to understand fully the deformational patterns of the Longitudinal Valley fault system, a major structure along the eastern suture of Taiwan, we mapped geomorphic features near the southern end of the Longitudinal Valley, where many well‐developed fluvial landforms record deformation along multiple strands of the fault. Our analysis shows that the Longitudinal Valley fault there comprises two major strands. The Luyeh strand, on the west, has predominantly reverse motion. The Peinan strand, on the east, has a significant left‐lateral component. Between the two strands, late Quaternary fluvial sediments and surfaces exhibit progressive deformation. The Luyeh strand dies out to the north, where it steps to the east and joins the Peinan strand to become the main strand of the reverse sinistral Longitudinal Valley fault. To the south, the Luyeh strand becomes an E‐W striking monocline. This suggests that the reverse motion on the Longitudinal Valley system decreases drastically at that point. The Longitudinal Valley fault system is therefore likely to terminate abruptly there and does not seem to connect to any existing structure further to the south. This abrupt structural change suggests that the development of the Longitudinal Valley suture occurs through discrete structural “jumps,” rather than by a continuous northward maturation.
New ice core evidence for a volcanic cause of the A.D. 536 dust veil
Authors: Larsen L. B. , Vinther B. M. , Briffa K. R. , Melvin T. M. , Clausen H. B. , Jones P. D. , Siggaard‐Andersen M.‐L. , Hammer C. U. , Eronen M. , Grudd H. , Gunnarson B. E. , Hantemirov R. M. , Naurzbaev M. M. , Nicolussi K.
Published: February 2008

New and well‐dated evidence of sulphate deposits in Greenland and Antarctic ice cores indicate a substantial and extensive atmospheric acidic dust veil at A.D. 533–534 ± 2 years. This was likely produced by a large explosive, near equatorial volcanic eruption, causing widespread dimming and contributing to the abrupt cooling across much of the Northern Hemisphere known from historical records and tree‐ring data to have occurred in A.D. 536. Tree‐ring data suggest that this was the most severe and protracted short‐term cold episode across the Northern Hemisphere in the last two millennia, even surpassing the severity of the cold period following the Tambora eruption in 1815.
Relationship between trends in temperature extremes and elevation in the eastern and central Tibetan Plateau, 1961–2005
Authors: You Qinglong , Kang Shichang , Pepin Nick , Yan Yuping
Published: February 2008

Trend magnitudes of 11 indices of temperature extremes at 71 stations with elevations above 2000 m a.s.l. in the eastern and central Tibetan Plateau (TP) during 1961–2005 are examined. Most trends in extremes are consistent with general warming in the TP. There are no significant correlations between elevation and trend magnitude of temperature extremes with the exception of TXn (coldest day temperature) and TX10 (cold day frequency). Thus an enhanced sensitivity of temperature extremes at higher elevations in the eastern and central TP is not apparent in the context of recent warming in this region. Although previous work showed a correlation between elevation and mean temperature trends in the TP, this analysis fails to substantiate this relationship for extremes. Analysis of trend magnitudes by topographic type and degree of urbanization show both factors to have a strong influence in this dataset, which overrides that of elevation.
Titan's magnetic field signature during the Cassini T34 flyby: Comparison between hybrid simulations and MAG data
Authors: Simon S. , Motschmann U. , Kleindienst G. , Glassmeier K.‐H. , Bertucci C. , Dougherty M. K.
Published: February 2008

During the T34 flyby on 19 July 2007, the Cassini spacecraft passed through the magnetic pile‐up region at Titan's ramside. The magnetic environment of Titan during this flyby is studied using a three‐dimensional hybrid simulation model. This approach treats the electrons of the plasma as a massless, charge‐neutralizing fluid, whereas the effects of finite ion gyroradii are taken into account by modeling the ions as individual particles. The simulation results are compared to data collected by the Cassini Magnetometer Instrument. The key features of the measured magnetic field signature have shown to be fully reproducible in the framework of the simulation model. Several signatures in the observed magnetic field can be ascribed to the passage of the Cassini spacecraft through the magnetic barrier upstream of Titan.
Residual strahls in solar wind electron dropouts: Signatures of magnetic connection to the Sun, disconnection, or interchange reconnection?
Authors: Crooker N. U. , Pagel C.
Published: February 2008

A recent assessment of suprathermal electron heat flux dropouts (HFDs) in the solar wind eliminated 90% as possible signatures of field lines disconnected from the Sun at both ends (Pagel et al., 2005b). The primary reason for elimination was the presence of a residual field‐aligned strahl presumably signaling field lines connected to the Sun. Using high‐time‐resolution data from the Wind spacecraft, this paper tests whether the residual strahls were an artifact of averaging over pitch angle distributions (PADs) with and without strahls. An automated search for PADs without strahls (flat PADs) yields an occurrence rate of only 14% within HFDs, but a detailed case study shows that these flat PADs are imbedded within intervals of nearly flat PADs, that is, PADS with residual strahls that cannot be artifacts of averaging. An attractive alternative is that the residual strahls result from intermixing of originally back‐scattered fluxes (haloes) of unequal intensities on field lines that have either disconnected or interchange reconnected at the Sun. A reevaluation of reported streaming of higher‐energy electrons in HFDs suggests a similar cause. While the high‐time‐resolution data show high variability of PAD profiles within HFDs, this paper reopens the possibility that a substantial fraction signal disconnection or interchange reconnection. Estimated occurrence rates of fields having undergone these processes based upon published HFD rates are of the same order of magnitude as the surprisingly low values of ∼1–5% recently predicted by a model of a balanced heliospheric flux budget (Owens and Crooker, 2007).