bluuebunny/crossref_metadata_2025 huggingface dataset:
Latent Factors Underlying Individual Differences in Attention Measures
Authors: Moosbrugger Helfried , Goldhammer Frank , Schweizer Karl
Published: July 2006

Following theoretical considerations that relate attention to perception and also to the executive control of performance in complex tasks ( Bundesen, 1990 ; Logan & Gordon, 2001 ), two latent factors underlying individual differences in attention measures are assumed: Perceptual attention and Executive attention. The included attention measures are derived from the neuropsychology-based attention model by Sturm and Zimmermann (2000) , the action-oriented five-component model by Neumann (1992) , and the working memory model according to Baddeley (1986) . Furthermore, one psychometric attention measure ( Moosbrugger & Goldhammer, 2005 ) was selected. A sample of 232 students aged between 19 and 40 completed a test battery of 11 attention and concentration tests. For investigating the appropriateness of the hypothesized two-factor structure, confirmatory factor models, including Perceptual attention and Executive attention as latent factors, were tested. The results support the two-factor structure and, thereby, the hypothesis, that perceptual and executive attention are major factors underlying individual differences in attention measures.
The Strengths and Difficulties Questionnaire in a Community Sample of Young Children in Flanders
Authors: Van Leeuwen Karla , Meerschaert Thierry , Bosmans Guy , De Medts Leen , Braet Caroline
Published: July 2006

This study investigates some psychometric properties of the Dutch version of the Strengths and Difficulties Questionnaire (SDQ), a brief measure for screening behavioral and emotional problems in children and adolescents. In two independent Flemish community samples of young children, parents (Sample 1: N = 532; Sample 2: N = 1086) and teachers (Sample 1: N = 512; Sample 2: N = 1049) of children aged 4-8 completed all items of the SDQ. Exploratory factor analysis and confirmatory factor analysis provided evidence for both a three- and a five-factor solution. Internal consistency and interrater reliability of the different SDQ scales were found to be satisfactory, except for the Conduct problems and the Peer problems scales. A good construct validity with the subscales of the well-established Child Behavior Checklist was found. A 2 (gender) × 2 (age groups: 4-5 and 6-7 years) ANOVA indicated that more hyperactivity/inattention problems and more internalizing behavior was reported for the oldest age group. More behavior problems were reported for boys than for girls, whereas girls were attributed more prosocial behavior.
A Revised 10-Item Version of the Achievement Motives Scale
Authors: Lang Jonas W.B. , Fries Stefan
Published: July 2006

The Achievement Motives Scale (AMS) is a well-established and frequently used scale to assess hope of success and fear of failure. In three studies with German-speaking samples (N = 3523, N = 132, N = 126), the authors developed a revised form of the AMS using confirmatory factor analysis. As found in previous research, the original 30-item set of the AMS did not provide an acceptable fit to a two-factor model. In contrast, a revised 10-item version (AMS-R) provided an adequate fit to the theoretically intended two-factor model. The adequate fit could be validated in cross-validation procedures. Furthermore, the revised scales provided adequate reliability, lower interscale correlations, and criterion-related validity with respect to typical criteria of achievement-related behavior.
Geologically recent tectonic, volcanic and fluvial activity on the eastern flank of the Olympus Mons volcano, Mars
Authors: Basilevsky A. T. , Werner S. C. , Neukum G. , Head J. W. , van Gasselt S. , Gwinner K. , Ivanov B. A.
Published: July 2006

We show evidence of very recent (≤25–40 Myr) geologic activity on the eastern flank of Olympus Mons volcano that includes a suite of fluvial (channel networks), volcanic (emplacement of lava flows and dikes), and tectonic (wrinkle ridges and troughs) processes. The combination and youth of these features confirms the importance of geological activity continuing to the present on Mars.
Global spectrum fluctuations for the β-Hermite and β-Laguerre ensembles via matrix models
Authors: Dumitriu Ioana , Edelman Alan
Published: July 2006

We study the global spectrum fluctuations for β-Hermite and β-Laguerre ensembles via the tridiagonal matrix models introduced previously by the present authors [J. Math. Phys. 43, 5830 (2002)], and prove that the fluctuations describe a Gaussian process on polynomials. We extend our results to slightly larger classes of random matrices.
Evaluation of alternative sum-over-states expressions for the first hyperpolarizability of push-pull π-conjugated systems
Authors: Champagne Benoît , Kirtman Bernard
Published: July 2006

A dipolar-free sum-over-states expression for the diagonal components of the first hyperpolarizability (β) tensor has been proposed by Kuzyk [Phys. Rev. A 72, 053819 (2005)] as an alternative to the traditional expression. We examine both alternatives for the longitudinal β of four typical push-pull π-conjugated systems using the ab initio CIS and CIS(D) schemes to approximate the excited state properties. Since they are each evaluated approximately the two SOS expressions yield different values for β and it is found that (i) they evolve symmetrically as the number of excited states is increased so that their average is nearly constant; (ii) in the static limit, the two values agree better with one another when their average is close to the “exact” correlated result; and (iii) frequency dispersion can affect the agreement between the alternative expressions. On the basis of (i) and (ii) it appears best for typical push-pull π-conjugated systems to estimate the static β, and the error in the value so obtained, by averaging the Kuzyk and traditional results.
Modified non-Abelian Toda field equations and twisted quasigraded Lie algebras
Authors: Skrypnyk T.
Published: July 2006

We construct a new family of quasigraded Lie algebras that admit the Kostant-Adler scheme. They coincide with special quasigraded deformations of twisted subalgebras of the loop algebras. Using them we obtain new hierarchies of integrable equations in partial derivatives which we call “modified” non-Abelian Toda field hierarchies.
Exploration of the yield-ratio method at Shenguang II laser facility
Authors: Zhao Zongqing , Chen Jiabin , Ding Yongkun , Chen Ming , Pu Yikang
Published: July 2006

In inertial confinement fusion implosion experiments with the primary-neutron yield as low as 107, the method of yield ratio is proposed to diagnose the areal density ⟨ρR⟩ at Shenguang II laser facility. Considering the detection efficiency and the time response, a new detector for detecting the secondary-neutron signal is developed, which locates 50cm away from the target. According to Monte Carlo N-particle simulation, 5-cm-thick lead shield was placed in front of the detector to shield x rays. In the 2004 experiments, the highest primary-neutron yield is 3.18×106, which is an order lower than expected. Inspite of this fact, a secondary-neutron signal is measured for the first time at the Shenguang II laser facility, which proves the method’s feasibility. The method will be used in the experiments at the prototype of Shenguang III laser facility.
Pressure effects on grain boundary plasticity in nanophase metals
Authors: Bringa E. M. , Caro A. , Leveugle E.
Published: July 2006

Grain boundary sliding is often the picture that explains computer simulation results and experiments on plasticity of nanophase materials. Using atomistic computer simulations we perform a detailed study of the effects of high hydrostatic pressure on nanophase Cu plasticity and find that it can be understood in terms of pressure dependent grain boundary sliding controlled by a Mohr-Coulomb law. This result explains recent findings on pressure-induced ultrahigh strength observed in computer simulations of shocks in nanophase Cu reported by Bringa et al. [Science 309, 1838 (2005)].
Optical phonon decay in bulk aluminum nitride
Authors: Song D. Y. , Holtz M. , Chandolu A. , Nikishin S. A. , Mokhov E. N. , Makarov Yu. , Helava H.
Published: July 2006

We report Raman studies of the E22 and A1(LO) symmetry phonons of bulk AlN from 13to375K. Based on observed dependences of the phonon energies and linewidths, and accounting for the temperature-dependent thermal expansion, we determine that both phonon lifetimes are limited by two-phonon decay. The E22 decays symmetrically. The A1(LO) asymmetrically decays into vibrations with energies 586 and 309cm−1 which we attribute to A1(TO) and LA phonons from the M point of the Brillouin zone.
In situ transmission electron microscopy study of the nanodomain growth in a Sc-doped lead magnesium niobate ceramic
Authors: Qu W. , Zhao X. , Tan X.
Published: July 2006

Sc doping enhances the B-site 1:1 cation ordering in the Pb(Mg1∕3Nb2∕3)O3 ceramic. At low doping levels, the electrical polar domains remain at the nanometer scale and the relaxor ferroelectric behavior persists. The electric field-induced relaxor to normal ferroelectric phase transition process was directly observed with an in situ transmission electron microscopy technique in a Sc-doped Pb(Mg1∕3Nb2∕3)O3 polycrystalline sample. It was found that the phase transition started at the grain boundary and took two steps to complete: the gradual coalescence of the polar nanodomains and the abrupt formation of the large wedge-shaped ferroelectric domains.
Direct evidence of N aggregation and diffusion in Au+ irradiated GaN
Authors: Jiang W. , Zhang Y. , Weber W. J. , Lian J. , Ewing R. C.
Published: July 2006

A surface amorphized layer and a buried disordered structure were created in gallium nitride (GaN) irradiated using 1.0MeV Au+ ions to fluences of 25 and 70Au+∕nm2 at room temperature. Bubbles of N2 gas within both the amorphized and disordered GaN are formed. A gradient profile with a lower N concentration in the amorphized region is observed, which provides direct evidence of N loss by diffusion in the Au+ irradiated GaN. These results are important to understanding the amorphization processes in GaN and may have significant implications for the design and fabrication of GaN-based devices.
Circular dichroism in second harmonic generation from oxidized Si (001)
Authors: Li Xiaoqin , Willits J. , Cundiff S. T. , Aarts I. M. P. , Stevens A. A E. , Dessau D. S.
Published: July 2006

Circular dichroism in second harmonic generation (SHG) is often related to molecules and materials with chiral structures. In this letter, we report circular dichroism in SHG from anisotropic achiral oxidized Si (001) at room temperature. The dichroism value depends on the azimuthal angles of the crystal axes. Due to the simple nonlinear susceptibility elements involved, we were able to attribute the dichroism in SHG to interference between particular terms of the bulk electric quadrupole and surface dipole contributions. The presence of a phase shift between the bulk and surface SHG is required to observe circular dichroism.
Spontaneous pulse generation using silicon controlled rectifier
Authors: Karunasiri Gamani
Published: July 2006

Spontaneous generation of voltage pulses was observed in a circuit consists of a silicon controlled rectifier (SCR) connected in series with a parallel RC circuit under dc bias. The pulse rate found to increase with the dc bias and saturated as pulse period reached the RC time constant. The injection of current into the SCR using a photodiode connected to the gate terminal increased the pulse rate with light intensity. This suggests that direct illumination of the reversed biased p-n junction of the SCR with light will allow the circuit to function as a pulse mode light detector.
High temperature ferromagnetism in Ni-doped In2O3 and indium-tin oxide
Authors: Peleckis Germanas , Wang Xiaolin , Dou Shi Xue
Published: July 2006

Observation of high temperature ferromagnetism in Ni-doped In2O3 and indium-tin-oxide (ITO) samples prepared by a solid state synthesis route is reported. Both Ni-doped compounds showed a clear ferromagnetism above 300K with the magnetic moments of 0.03–0.06μB∕Ni and 0.1μB∕Ni at 300 and 10K, respectively. Ni-doped In2O3 samples showed a typical semiconducting behavior with a room temperature resistivity of ρ∼2Ωcm, while Ni-doped ITO samples were metallic with ρ∼2×10−2Ωcm. Analysis of different conduction mechanisms suggested that variable range hopping model explains our ρ-T data for the Ni-doped In2O3 sample the best.
Thermal stability and band alignments for Ge3N4 dielectrics on Ge
Authors: Wang S. J. , Chai J. W. , Pan J. S. , Huan A. C. H.
Published: July 2006

Ge 3 N 4 dielectrics were prepared on Ge surface by in situ direct atomic source nitridation. The thermal stability and band alignments for Ge3N4∕Ge interfaces have been studied by using high-resolution x-ray photoemission spectroscopy. The in situ thermal treatment shows that Ge3N4 film has higher temperature thermal stability up to 550°C in vacuum. The conduction- and valence-band offsets at Ge3N4∕Ge interface are quite asymmetrical with the values of 2.22 and 1.11eV, respectively.
Mn
3
Sn
2
: A promising material for magnetic refrigeration
Authors: Mazet T. , Ihou-Mouko H. , Malaman B.
Published: July 2006

Mn 3 Sn 2 presents two second-order magnetic transitions of ferromagnetic origin at TC1∼262K and TC2∼227K. Both transitions give peaks of similar magnitude (ΔSMmax∼27mJcm−3K−1 for ΔH=5T) in the temperature dependence of the magnetic entropy change yielding an anomalous magnetocaloric response approaching that of a two-component hybrid material. Its refrigerant capacity of ∼1.1Jcm−3 (ΔH=5T) for an optimal reversible cycle with cold and hot ends at ∼220 and ∼280K is about half that of the best known magnetic refrigerants working around room temperature. However, Mn3Sn2 possess several advantages making it a promising candidate for magnetic refrigeration applications: (i) it has a large temperature span with a roughly constant ΔSM, (ii) it is not subjected to hysteresis losses, and (iii) it is made from low-cost and nontoxic elements.
Origin of the red luminescence in Mg-doped GaN
Authors: Zeng S. , Aliev G. N. , Wolverson D. , Davies J. J. , Bingham S. J. , Abdulmalik D. A. , Coleman P. G. , Wang T. , Parbrook P. J.
Published: July 2006

Optically detected magnetic resonance and positron annihilation spectroscopy experiments have been employed to study magnesium-doped GaN layers grown by metal-organic vapor phase epitaxy. As the Mg doping level is changed, the combined experiments reveal a strong correlation between the vacancy concentrations and the intensity of the red photoluminescence band at 1.8eV. The analysis provides strong evidence that the emission is due to recombination in which electrons both from effective-mass donors and from deeper donors recombine with deep centers, the deep centers being vacancy-related defects.
Lithium doping of pentacene for electrochemical hydrogen storage
Authors: Fang Baizeng , Zhou Haoshen , Honma Itaru
Published: July 2006

This study reports in detail the practical realization of electrochemical hydrogen storage in porous metal-incorporated nanostructured organic compounds, Li-doped pentacene, which has been synthesized by potentiostatic electrolysis and characterized by x-ray diffraction, Fourier transform infrared spectra analysis, and galvanostatic current charge-discharge measurements. Although the lithium doping is at a very low level the conductivity of pentacene increases considerably after the doping, which makes the ordered layer-stacked Li-doped pentacene very promising as electrode material for electrochemical hydrogen storage, and a discharge capacity of ca. 239mAh∕g (corresponding to 0.89wt% hydrogen storage) has been achieved for the Li-doped pentacene electrode.
Effect of the oxidation process on the electrical characteristics of 4H–SiC p-channel metal-oxide-semiconductor field-effect transistors
Authors: Okamoto Mitsuo , Tanaka Mieko , Yatsuo Tsutomu , Fukuda Kenji
Published: July 2006

We fabricated inversion-type 4H–SiC p-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). The electrical properties of the p-channel MOSFETs depended on the gate oxidation process. We found that wet oxidation process was effective for improving the channel mobility of the p-channel MOSFET, and obtained the field-effect channel mobility μFE of 15.6cm2∕Vs by using that process. Measurements of the p-type MOS capacitors implied that the SiO2∕SiC interface states around the valence band affected the channel mobility and threshold voltage of the p-channel MOSFETs. We also investigated temperature dependences.
Bait-delivered pimozide causes precocious embryo implantation in mink: a fertility control option for the exotic stoat?
Authors: Marks Clive A. , Lindeberg Heli , Van Cleeff Judy
Published: July 2006

Stoats (Mustela erminea), an exotic pest in New Zealand, threaten the conservation of several ground-nesting bird species and broad-scale methods for their control are sought. Females are seasonally monestrous, show a 9-month period of obligatory diapause and usually do not breed more than once in their lives. A bait-delivered agent that terminates diapause and results in a non-viable embryo may have a significant impact on their reproductive success. Prolactin (PRL) is hypothesised to be the only gonadotrophin required for renewal of luteal activity and blastocyst implantation in some mustelids. We investigated the effects of bait-delivered dopamine (DA) antagonists (which stimulate the release of PRL) using a mink model (Mustela vison), a species that maintains a short period of diapause. A bait dose of 0.8 mg kg–1 of pimozide was more effective in elevating PRL levels than equivalent doses of fluphenazine, sulpiride (P < 0.01) or haloperidol (P < 0.05). Bait doses of 1.6 mg kg–1 pimozide given at Days 0, 3, 9 and 11 after mating caused a significant reduction in the length of pregnancy compared with a positive control and placebo (46 days v. 51 days), indicating early termination of diapause (P < 0.01). Pimozide doses caused higher elevations in PRL concentration relative to the oral placebo by Day 12, but mean PRL levels fell below all other groups by Day 18. A borderline significant increase in progesterone (P4) secretion compared with the oral placebo was detected at Day 18. These results suggest that bait-delivered pimozide can elevate PRL outside of the normal breeding season and doses of 1.6 mg kg–1 are effective in terminating embryonic diapause in mink. The implications and limitations of these data are discussed with reference to the use of bait-delivered DA antagonists as a possible means to affect the reproductive success of wild stoats.
Leucocyte population changes in the reproductive tract of the ewe in response to insemination
Authors: Scott Jennifer L. , Ketheesan Natkunam , Summers Phillip M.
Published: July 2006

Leucocyte changes after insemination may affect conceptus implantation, but information regarding leucocyte populations in the ruminant reproductive tract is limited. The present study investigated changes in leucocyte populations and distribution in the ovine reproductive tract following oestrus and insemination. Fifteen ewes were mated with a ram for 1 h and their reproductive tracts collected 3, 6, 18, 24 or 48 h later. Another 15 ewes were used as oestrus controls. Tissues were collected from 10 sites in each reproductive tract and stained with haematoxylin and eosin, Toluidine blue and immunohistochemically using a monoclonal CD68 antibody. Luminal mucus smears were collected from seven sites and stained with a modified Wright’s stain and immunohistochemically. Neutrophils, eosinophils, mast cells and macrophages were identified and quantified, and temporal changes in their distribution within tissues were examined. Neutrophils and macrophages increased significantly (P < 0.05) in posterior cervical and uterine tissues following insemination. In uterine tissues, neutrophils peaked at 6 h after insemination, whereas macrophages peaked at 18–24 h. Mast cells decreased and eosinophils remained constant. Neutrophils increased significantly (P < 0.05) in the cervical and uterine lumen following insemination. In conclusion, leucocyte population changes after insemination vary between different sites in the ovine reproductive tract and may contribute to pregnancy establishment.
Transcription profile during maternal to zygotic transition in the mouse embryo
Authors: Li Xing-Yu , Cui Xiang-Shun , Kim Nam-Hyung
Published: July 2006

To gain insight into early embryo development, we used microarray technology to compare gene expression profiles in metaphase II oocytes and one- (1C), two- (2C) and four-cell (4C) embryos. Differences in spot intensities were normalised and grouped using Avadis Prophetic software platform (version 3.3; Strand Genomics, Bangalore, India) and categories were based on the PANTHER and Gene Ontology classification systems. We examined 6927 genes and identified those preferentially expressed in 1C or 2C embryos. We found 1261 genes that were more highly expressed (P < 0.05) in 1C compared with 2C embryos and 1480 genes showing enhanced expression in 2C embryos. Similarly, we investigated 6581 genes present in 2C and 4C embryos and identified 841 that are expressed to a greater extent at the 2C stage and 905 that are more highly expressed at the 4C stage. Using PANTHER classification, genes that were upregulated and downregulated in 2C embryos compared with 1C and 4C embryos were grouped according to their protein functions, which included developmental processes, electron transport, lipid, fatty acid and steroid metabolism, nucleoside, nucleotide and nucleic acid metabolism, protein metabolism and modification, signal transduction and transport, among others. Real time reverse transcription–polymerase chain reaction was performed to confirm differential expression of 14 selected genes. The identification of the genes being expressed will provide insight into the complex gene regulatory networks affecting zygotic genome activation and further development.
Extended gene analysis can increase specificity of neonatal screening for cystic fibrosis
Authors: Mérelle Marieke E. , Scheffer Hans , De Jong Debora , Dankert‐Roelse Jeannette E.
Published: July 2006

Aim: To assess whether carriers and patients can be accurately identified by extended gene analysis for cystic fibrosis (CF) in dried blood spots. Methods: A blinded analysis was performed in 10‐mm2 blood spots on Guthrie cards, punched as if to remove material for the IRT test, from 10 CF patients and 10 carriers with known CF mutations. Genomic DNA was isolated. Aliquots of 1 µl dissolved DNA were used for subsequent PCRs. Analysis of the ?F508 mutation was followed by an oligonucleotide ligation assay. Denaturing gradient gel electrophoresis of the whole CFTR gene was carried out in samples with only one identified mutation. Amplicons revealing an aberrant pattern were sequenced. Results: In all cases, the blood‐spot genotype was identical to that previously determined from whole‐blood analysis. Estimated time needed to complete the procedure in a series of Guthrie cards was 3–4 wk.

Conclusion: Extended gene analysis in dried blood spots can discriminate CF patients and carriers. If proven equally reliable in larger series, an approach to neonatal screening in which tests are only considered as screen positive when two CF mutations are found is possible. This can increase the specificity of the screening programme, and carrier detection can practically be avoided.
On transient breastfeeding‐related chylomicronaemia syndrome
Authors: Rosipal Štefan
Published: July 2006

This paper reports on two male infants with abnormally high levels of serum triacylglycerols (>15.00 mmol/l) and massive accumulation of chylomicrons. Pathological lipidograms were observed during breastfeeding only and were typical of a rare chylomicronaemia syndrome. Laboratory abnormalities were detected accidentally in the otherwise healthy infants. An unrecognized modulating factor in fresh mother's milk caused transitory decreased activity of hydrolytic complex for chylomicrons and very‐low‐density lipoproteins, probably due to a dysfunction of lipoprotein lipase. The normalization of lipidograms suggested that the catalytic activity of lipoprotein lipase rapidly recovered after weaning. Pathogenesis moved more towards an immune disorder, to the production of (auto)antibodies against a component of the lipolytic system. Mother's milk should be substituted with banked donor human milk, but this is not an unambiguous demand. Conclusion: Fresh mother's milk caused a decrease in the activity of lipolytic enzyme (lipoprotein lipase). The massive hypertriacylglycerolaemia quickly disappeared after weaning. Two infants with this transient chylomicronaemia syndrome were asymptomatic.
Kicking off adaptive immunity: the discovery of dendritic cells
Authors: Katsnelson Alla
Published: July 2006

In 1973, Ralph Steinman and Zanvil Cohn discovered an unusual looking population of cells with an unprecedented ability to activate naive T cells. Dubbed “dendritic cells,” these cells are now known as the primary instigators of adaptive immunity.
Modelling and rapid simulation of multiple red blood cell light scattering
Authors: Zohdi T.I , Kuypers F.A
Published: July 2006

The goal of this work is to develop a computational framework to rapidly simulate the light scattering response of multiple red blood cells. Because the wavelength of visible light (3.8×10
−7
 m≤
λ
≤7.2×10
−7
 m) is approximately an order of magnitude smaller than the diameter of a typical red blood cell scatterer (
d
≈8×10
−6
 m), geometric ray-tracing theory is applicable, and can be used to quickly ascertain the amount of optical energy, characterized by the Poynting vector, that is reflected and absorbed by multiple red blood cells. The overall objective is to provide a straightforward approach that can be easily implemented by researchers in the field, using standard desktop computers. Three-dimensional examples are given to illustrate the approach and the results compare quite closely to experiments on blood samples conducted at the Children's Hospital Oakland Research Institute (CHORI).
Atomistic modelling of fatigue crack growth and dislocation structuring in FCC crystals
Authors: Potirniche G.P , Horstemeyer M.F , Gullett P.M , Jelinek B
Published: July 2006

Fatigue damage in face-centred cubic crystals by dislocation substructuring and crack growth was computationally simulated at the atomic scale. Single-crystal copper specimens with approximately 200 000 atoms and an initial crack were subjected to fatigue loading with a constant strain amplitude of
ϵ
max
=0.01 and a load ratio of
R
=
ϵ
min
/
ϵ
max
=0.75. Cyclic plastic deformation around the crack tip is the main influencing factor for the propagation mechanisms of nanocracks. The main crack-propagation mechanisms occurred either by void nucleation in the high-density region near the crack tip or by fatigue cleavage of the atomic bonds in the crack plane. Fatigue crack growth at grain boundaries was also studied. For high misorientation angle grain boundaries, the crack path deviated while moving from one grain to another. For low crystal misorientations, the crack did not experience any significant out-of-plane deviation. For a large crystal misorientation, voids were observed to nucleate at grain boundaries in front of the crack tip and link back with the main crack. During fatigue loading, dislocation substructures were observed to develop throughout the atomic lattices. Fatigue crack growth rates for nanocracks were computed and compared with growth rates published in the literature for microstructurally small cracks (micron range) and long cracks (millimetre range). The computed growth rates for nanocracks were comparable with those for small cracks at the same stress intensity ranges and they propagated below the threshold for long cracks.
The large number coincidence, the cosmic coincidence and the critical acceleration
Authors: Funkhouser Scott
Published: July 2006

The coincidence problem among the pure numbers of order near 10
40
is resolved with the Raychaudhuri and Friedmann–Robertson–Lemaitre–Walker equations and a trivial relationship involving the fine structure constant. The fact that the large number coincidence occurs only in the same epoch in which other coincidences among cosmic parameters occur could be considered a distinct coincidence problem suggesting an underlying physical connection. A natural set of scaling laws for the cosmological constant and the critical acceleration is identified that would resolve the coincidence among cosmic coincidences.
Controls on the distribution of productivity and organic resources in Antarctic Dry Valley soils
Authors: Hopkins D.W , Sparrow A.D , Novis P.M , Gregorich E.G , Elberling B , Greenfield L.G
Published: July 2006

The Antarctic Dry Valleys are regarded as one of the harshest terrestrial habitats on Earth because of the extremely cold and dry conditions. Despite the extreme environment and scarcity of conspicuous primary producers, the soils contain organic carbon and heterotrophic micro-organisms and invertebrates. Potential sources of organic compounds to sustain soil organisms include
in situ
primary production by micro-organisms and mosses, spatial subsidies from lacustrine and marine-derived detritus, and temporal subsidies (‘legacies’) from ancient lake deposits. The contributions from these sources at different sites are likely to be influenced by local environmental conditions, especially soil moisture content, position in the landscape in relation to lake level oscillations and legacies from previous geomorphic processes. Here we review the abiotic factors that influence biological activity in Dry Valley soils and present a conceptual model that summarizes mechanisms leading to organic resources therein.
Disruptive contrast in animal camouflage
Authors: Stevens Martin , Cuthill Innes C , Windsor Amy M.M , Walker Hannah J
Published: July 2006

Camouflage typically involves colour patterns that match the background. However, it has been argued that concealment may be achieved by strategic use of apparently conspicuous markings. Recent evidence supports the theory that the presence of contrasting patterns placed peripherally on an animal's body (disruptive coloration) provides survival advantages. However, no study has tested a key prediction from the early literature that disruptive coloration is effective even when some colour patches do not match the background and have a high contrast with both the background and adjacent pattern elements (disruptive contrast). We test this counter-intuitive idea that conspicuous patterns might aid concealment, using artificial moth-like targets with pattern elements designed to match or mismatch the average luminance (lightness) of the trees on which they were placed. Disruptive coloration was less effective when some pattern elements did not match the background luminance. However, even non-background-matching disruptive patterns reduced predation relative to equivalent non-disruptive patterns or to unpatterned controls. Therefore, concealment may still be achieved even when an animal possesses markings not found in the background. Disruptive coloration may allow animals to exploit backgrounds on which they are not perfectly matched, and to possess conspicuous markings while still retaining a degree of camouflage.
The relationship between migratory behaviour, memory and the hippocampus: an intraspecific comparison
Authors: Pravosudov Vladimir V , Kitaysky Alexander S , Omanska Alicja
Published: July 2006

It has been hypothesized that memory-demanding ecological conditions might result in enhanced memory and an enlarged hippocampus, an area of the brain involved in memory processing, either via extensive memory experience or through evolutionary changes. Avian migration appears to represent one of such memory-demanding ecological conditions. We compared two subspecies of the white-crowned sparrow: migratory
Zonotrichia leucophrys gambelii
and non-migratory
Z. l. nuttalli
. Compared to non-migratory
Z. l. nuttalli
, migratory
Z. l. gambelii
showed better memory performance on spatial one-trial associative learning tasks and had more hippocampal neurons. Migratory subspecies also had larger hippocampi relative to the remainder of the telencephalon but not relative to body mass. In adults, the differences between migratory and non-migratory sparrows were especially pronounced in the right hippocampus. Juvenile migratory
Z. l. gambelii
had relatively larger hippocampal volume compared to juvenile non-migratory
Z. l. nuttalli
. Adult migratory
Z. l. gambelii
had more neurons in their right hippocampus compared to juveniles but such differences were not found in non-migratory
Z. l. nuttalli
. Our results suggest that migratory behaviour might be related to enhanced spatial memory and an enlarged hippocampus with more neurons, and that differences in the hippocampus between migratory and non-migratory sparrows might be experience-dependent. Furthermore, for the first time our results suggest that the right hippocampus, which encodes global spatial information, might be involved in migratory behaviour.
Tsunami science before and beyond Boxing Day 2004
Authors: Synolakis Costas E , Bernard Eddie N
Published: July 2006

Tsunami science has evolved differently from research on other extreme natural hazards, primarily because of the unavailability until recently of instrumental recordings of tsunamis in the open ocean. Here, the progress towards developing tsunami inundation modelling tools for use in inundation forecasting is discussed historically from the perspective of hydrodynamics. The state-of-knowledge before the 26 December 2004 tsunami is described. Remaining aspects for future research are identified. One, validated inundation models need to be further developed through benchmark testing and instrumental tsunameter measurements and standards for operational codes need to be established. Two, a methodology is needed to better quantify short-duration impact forces on structures. Three, the mapping of vulnerable continental margins to identify unrecognized hazards must proceed expeditiously, along with palaeotsunami research to establish repeat intervals. Four, the development of better coupling between deforming seafloor motions and model initialization needs further refinement. Five, in an era of global citizenship, more comprehensive educational efforts on tsunami hazard mitigation are necessary worldwide.
Occupational peri‐ocular contact dermatitis due to sensitization against black rubber components of a microscope
Authors: Kuijpers D. I. M. , Hillen F. , Frank J. A
Published: July 2006

A 24‐year‐old female working in the Department of Pathology of a University Hospital developed an acute peri‐ocular eczema clearly being related to her daily work at the microscope. Patch testing revealed delayed type hypersensitivity against the black rubber mix, N‐isopropyl‐N ′‐phenyl paraphenylenediamine, N‐cyclohexyl‐N ′‐phenyl paraphenylenediamine and the rubber ring situated on the ocular of the respective microscope. This is the first report, to our knowledge, on peri‐orbital allergic contact eczema because of sensitization with rubber components of a microscope.
Unconsumed precursors and couplers after formation of oxidative hair dyes
Authors: Rastogi Suresh Chandra , Søsted Heidi , Johansen Jeanne Duus , Menné Torkil , Bossi Rossana
Published: July 2006

Contact allergy to hair dye ingredients, especially precursors and couplers, is a well‐known entity among consumers having hair colouring done at home or at a hairdresser. The aim of the present investigation was to estimate consumer exposure to some selected precursors (p‐phenylenediamine, toluene‐2,5‐diamine) and couplers (3‐aminophenol, 4‐aminophenol, resorcinol) of oxidative hair dyes during and after hair dyeing. Concentrations of unconsumed precursors and couplers in 8 hair dye formulations for non‐professional use were investigated, under the conditions reflecting hair dyeing. Oxidative hair dye formation in the absence of hair was investigated using 6 products, and 2 products were used for experimental hair dyeing. In both presence and absence of hair, significant amounts of unconsumed precursors and couplers remained in the hair dye formulations after final colour development. Thus, up to 1.1% p‐phenylenediamine (PPD), 0.04% toluene‐2,5‐diamine, 0.02% 3‐aminophenol and 0.02% resorcinol were found in the hair dye formulation after the required colour was developed. The consumers are thus exposed to precursors and couplers of oxidative hair dyes, both during and after hair dyeing, when the hair is washed. Furthermore, the consumers are also expected to be exposed to intermediates of oxidative hair dyes. The allergenic potential of oxidative hair dyes as well as the intermediates of these remains unknown.
Tobacco consumption and its association with illicit drug use among men in Bangladesh
Authors: Khan M. M. H. , Aklimunnessa K. , Kabir M. A. , Kabir M. , Mori Mitsuru
Published: July 2006

Aims  This study examined the association of tobacco consumption (smoking and chewing) with illicit drug use among Bangladesh males.

Design  Cross‐sectional survey data from the Bangladesh Demographic and Health Survey 2004 were used.

Setting  Bangladesh.

Participants  A total of 4297 males aged 15–54 years.

Measurements  Age, education, religion, marital status, place of residence; tobacco consumption such as cigarette and bidi smoking, chewing sada, pata, tobacco leaves, gul, betel quid with zarda; taking illicit drugs such as ganja, charas, heroin, pethedine, phensidyl; having sexually transmitted diseases (STDs).

Findings  Overall prevalence of tobacco consumption was 59%. Bidi smoking (29.6%), cigarette smoking (27.8%) and chewing betel quid with tobacco/zarda (17.5%) were predominant. Overall prevalence of illicit drug use was 4%. Ganja was the main drug (3%), followed by phensidyl (0.8%), heroin (0.3%) and charas (0.3%). Age, education, place of residence, marital status, having STDs, premarital and extra‐marital sex were associated significantly with tobacco smoking. Almost all variables were also associated significantly with illicit drug use. Smoking cigarettes and bidi and eating tobacco leaves/shada pata/gul showed significantly positive associations with illicit drug use when adjusted for other variables.

Conclusions  Tobacco consumption is common and associated positively with the illicit drug use among males in Bangladesh.
Tobacco industry sponsorship of a book and conflict of interest
Authors: Hong Mi‐Kyung , Bero Lisa A.
Published: July 2006

Aim  The tobacco industry has hidden its involvement in the design, conduct and publication of scientific research articles and has used the articles to argue against tobacco regulation. The objective of this study is to examine tobacco industry involvement in the development of scientific books.

Design  Qualitative analysis of previously secret internal tobacco industry documents retrieved from the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu). Information from the documents was supplemented with material from Internet searches, the National Center for Biotechnology Information Pubmed database and interviews with individuals involved in book publication.

Findings  Between 1997 and 1999 the tobacco industry sponsored a monograph, entitled ‘Analytical Determination of Nicotine and Related Compounds and their Metabolites’, that examined the measurement and metabolism of nicotine. The tobacco industry recruited Elsevier Science to publish the monograph. Tobacco industry executives, lawyers and scientists reviewed the chapters. One use of the monograph was to stimulate collaborative efforts between academic and tobacco industry scientists. Another was to provide the book to a government regulatory agency reviewing the teratogenic effects of nicotine.

Conclusion  Our findings show the breadth of tobacco industry engagement in scientific knowledge production and dissemination, and its motives for sponsoring scientific literature. The industry’s effort to gain credibility through collaboration with academic scientists raises questions regarding the ethics of accepting tobacco industry funding for publication. Scientists who collaborate on publications sponsored by the tobacco industry must consider the full implications of these joint efforts.
Comparative study between nadolol and 5‐isosorbide mononitrate vs. endoscopic band ligation plus sclerotherapy in the prevention of variceal rebleeding in cirrhotic patients: a randomized controlled trial
Authors: ROMERO G. , KRAVETZ D. , ARGONZ J. , VULCANO C. , SUAREZ A. , FASSIO E. , DOMINGUEZ N. , BOSCO A. , MUÑOZ A. , SALGADO P. , TERG R.
Published: July 2006

Background  After variceal bleeding, cirrhotic patients should receive secondary prophylaxis.

Aim  To compare nadolol plus 5‐isosorbide mononitrate (5‐ISMN) with endoscopic band ligation. The end points were rebleeding, treatment failure and death.

Methods  One hundred and nine cirrhotic patients with a recent variceal bleeding were randomized: nadolol plus 5‐ISMN in 57 patients and endoscopic band ligation in 52 patients.

Results  The mean follow‐up was 17 and 19 months in nadolol plus 5‐ISMN and endoscopic band ligation groups, respectively. No differences were observed between groups in upper rebleeding (47% vs. 46%), variceal rebleeding (40% vs. 36%), failure (32% vs. 22%), major complications (7% vs. 13.5%) and death (19% vs. 20%), respectively. The actuarial probability of remaining free of rebleeding, failure and deaths were similar in both groups. Time to rebleeding shows that endoscopic band ligation patients had an early rebleed, with a median of 0.5 month (95% CI: 0.0–4.2) compared with patients from nadolol plus 5‐ISMN, 7.6 months (95% CI: 2.9–12.3, P < 0.013). Multivariate analysis indicated that outcome‐specific predictive factor(s) for rebleeding was Child A vs. B + C (P < 0.01); for failure was Child A vs. B + C (P < 0.02); and for death ascites (P < 0.01) and rebleeding (P < 0.02).

Conclusion  This trial suggests no superiority of endoscopic band ligation over nadolol plus 5‐ISMN mononitrate for the prevention of rebleeding in cirrhotic patients.
Analysis of population differentiation in North Eurasian cattle (Bos taurus) using single nucleotide polymorphisms in three genes associated with production traits
Authors: Li M. H. , Adamowicz T. , Switonski M. , Ammosov I. , Ivanova Z. , Kiselyova T. , Popov R. , Kantanen J.
Published: July 2006

Single nucleotide polymorphisms (SNPs) in growth hormone 1 (GH1), insulin‐like growth factor 1 (IGF1) and leptin (LEP), all candidates for production traits in cattle, were characterized in North Eurasian cattle breeds. Allele frequencies of IGF1 exhibited significant (P < 0.05) deviation from neutral expectation and therefore, might be associated with divergence in North Eurasian cattle because of genetic selection. Allele frequencies and lower heterozygosity of LEP may indicate a recent introduction of an alternative allele in this geographic region. Locus FST estimates were highest for IGF1 (0.151, σ = 0.042) and lowest for GH (0.062, σ = 0.020). Our results suggest a slightly higher population differentiation across the candidate genes (FST = 0.108) than across microsatellites (FST = 0.095), possibly because of selection and stochastic effects.
An amylase gene polymorphism is associated with growth differences in the Pacific cupped oyster Crassostrea gigas
Authors: Prudence M. , Moal J. , Boudry P. , Daniel J. Y. , Quéré C. , Jeffroy F. , Mingant C. , Ropert M. , Bédier E. , Van Wormhoudt A. , Samain J. F. , Huvet A.
Published: July 2006

This study investigated the non‐neutrality of genetic polymorphism in two alpha‐amylase genes (AMYA and AMYB) in the oyster Crassostrea gigas. Bi‐parental oyster families, bred to be polymorphic for markers in these genes, were monitored for growth and survival for 1 year under standard culture conditions in two French production sites. Within‐family genotype frequencies indicated that the two amylase genes were closely linked (c. 1.7 cM). Within two of three families, significant differences in growth were observed between genotypes at one of the two production sites, suggesting that this polymorphism is not neutral and might be under selection because of its role in digestive function. Estimated daily yields were different between amylase genotypes, indicating the potential value of amylase markers in selective breeding programmes to improve oyster growth.
Quantitative trait loci mapping for fatty acid composition traits in perirenal and back fat using a Japanese wild boar × Large White intercross
Authors: Nii M. , Hayashi T. , Tani F. , Niki A. , Mori N. , Fujishima‐Kanaya N. , Komatsu M. , Aikawa K. , Awata T. , Mikawa S.
Published: July 2006

Here, we analysed quantitative trait loci (QTL) for fatty acid composition, one of the factors affecting fat quality, in a Japanese wild boar × Large White cross. We found 25 significant effects for 17 traits at 13 positions at the 5% genome‐wise level, of which 16 effects for 12 traits at 10 positions were significant at the 1% level. QTL for saturated fatty acids (SFA) in back fat were mapped to swine (Sus scrofa) chromosomes (SSC) 1p, 9 and 15. QTL for unsaturated fatty acids in back fat were mapped to SSC1p, 1q, 4, 5, 9, 15 and 17. Using a regression model that fits back fat thickness as a covariate, two of the QTL for linoleic acid content on SSC4 and SSC17 were not significant, but one QTL for total SFA composition was detected on SSC5 with correction for back fat thickness. Wild boar alleles at six of seven QTL tended to increase SFAs and to decrease unsaturated fatty acids. QTL for fatty acid composition in perirenal fat were mapped on SSC2, 3, 4, 5, 6, 14, 16 and X. QTL for melting point (in back fat samples) were mapped on SSC1, 2 and 15. Wild boar alleles in QTL on SSC1 and SSC15 were associated with elevated melting points whereas those on SSC2 were associated with lower melting point measurements.
Acquired resistance to activated protein C (aAPCR) in multiple myeloma is a transitory abnormality associated with an increased risk of venous thromboembolism
Authors: Elice Francesca , Fink Louis , Tricot Guido , Barlogie Bart , Zangari Maurizio
Published: July 2006

Acquired activated protein C resistance (aAPCR), not associated with factor V Leiden, has been described in cancer patients with an increased risk of venous thromboembolism (VTE). APCR was determined in 1178 myeloma patients using an activated partial thromboplastin time‐based resistance assay in the presence of excess of factor V‐deficient plasma; polymerase chain reaction amplification of genomic DNA was used to detect factor V Leiden mutation. A total of 109 patients were found to have abnormal APCR and one‐third of them were carriers for the mutation. With a median follow‐up of 40 months, the presence of aAPCR was associated with a significantly increased risk of thrombosis (P ≤ 0·001). APCR was measured again after treatment in 31 patients with abnormal baseline values and had normalised in 30 of them. This study indicates that aAPCR is the most common single transitory baseline coagulation abnormality associated with VTE in myeloma patients.