bluuebunny/crossref_metadata_2025 huggingface dataset:
Bis(7)‐tacrine attenuates β amyloid‐induced neuronal apoptosis by regulating L‐type calcium channels
Authors: Fu Hongjun , Li Wenming , Lao Yuanzhi , Luo Jialie , Lee Nelson T. K. , Kan Kelvin K. W. , Tsang Hing Wai , Tsim Karl W. K. , Pang Yuanping , Li Zhiwang , Chang Donald C. , Li Mingtao , Han Yifan
Published: June 2006

β Amyloid protein (Aβ) and acetylcholinesterase (AChE) have been shown to be closely implicated in the pathogenesis of Alzheimer's disease. In the current study, we investigated the effects of bis(7)‐tacrine, a novel dimeric AChE inhibitor, on Aβ‐induced neurotoxicity in primary cortical neurons. Bis(7)‐tacrine, but not other AChE inhibitors, elicited a marked reduction of both fibrillar and soluble oligomeric forms of Aβ‐induced apoptosis as evidenced by chromatin condensation and DNA specific fragmentation. Both nicotinic and muscarinic receptor antagonists failed to block the effects of bis(7)‐tacrine. Instead, nimodipine, a blocker of L‐type voltage‐dependent Ca2+ channels (VDCCs), attenuated Aβ neurotoxicity, whereas N‐, P/Q‐ or R‐type VDCCs blockers and ionotropic glutamate receptor antagonists did not. Fluorescence Ca2+ imaging assay revealed that, similar to nimodipine, bis(7)‐tacrine reversed Aβ‐triggered intracellular Ca2+ increase, which was mainly contributed by the extracellular Ca2+ instead of endoplasmic reticulum and mitochondria Ca2+. Concurrently, using whole cell patch‐clamping technique, it was found that bis(7)‐tacrine significantly reduced the augmentation of high voltage‐activated inward calcium currents induced by Aβ. These results suggest that bis(7)‐tacrine attenuates Aβ‐induced neuronal apoptosis by regulating L‐type VDCCs, offers a novel modality as to how the agent exerts neuroprotective effects.
Folliculitis Spinulosa Decalvans: An Uncommon Entity within the Keratosis Pilaris Atrophicans Spectrum
Authors: Di Lernia Vito , Ricci Cinzia
Published: June 2006

Abstract:  Folliculitis spinulosa decalvans is an uncommon condition characterized by follicular hyperkeratosis, followed by scarring alopecia. We report a 12‐year‐old boy affected by keratotic papules of the scalp and keratosis pilaris of the limbs who developed erythema, pustules, and scale crusts on the scalp associated with scarring alopecia. Histologic examination showed follicular and interfollicular hyperkeratosis, follicular plugging, mild inflammation, and focal scarring. A transient remission of the inflammatory changes on the scalp was obtained after treatment with isotretinoin. The follicular spinulous hyperkeratosis persisted. A severe relapse of the scalp inflammation was observed during a 2‐year follow‐up.
Dynamics of diamondback moth oviposition in the presence of a highly preferred non‐suitable host
Authors: Badenes‐Perez Francisco R. , Nault Brian A. , Shelton Anthony M.
Published: June 2006

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), highly prefers to oviposit on yellow rocket, Barbarea vulgaris (R. Br.) (Cruciferae) var. arcuata, despite larvae not being able to survive on it, suggesting it may have potential as a trap crop. In a no‐choice greenhouse experiment, P. xylostella laid 28% more eggs on B. vulgaris than on cabbage. Within the B. vulgaris plant, P. xylostella laid 3.7 times more eggs on younger than older leaves. Furthermore, we demonstrated that in the presence of B. vulgaris volatiles, P. xylostella laid 23% more eggs on cabbage plants than when B. vulgaris volatiles were absent. Because increased oogenesis in the presence of B. vulgaris could complicate the use of this host as a trap crop for P. xylostella, we wanted to examine levels of oogenesis in varying mixtures of cabbage and B. vulgaris. In outdoor screenhouse experiments, P. xylostella laid a decreasing percentage of eggs on cabbage as the percentage of B. vulgaris increased. However, the total number of eggs laid on cabbage did not differ among treatments, suggesting that the presence of B. vulgaris may have stimulated P. xylostella oviposition. In the field, total oviposition in cabbage plots containing B. vulgaris was 6.3 times higher than in cabbage plots without B. vulgaris. However, in plots with B. vulgaris, P. xylostella laid 99% of the eggs on B. vulgaris and oviposition on cabbage plants was 6.2 times lower than in the plots without B. vulgaris. The results of this study are discussed according to P. xylostella egg‐laying behavior and life history as it relates to its interaction with B. vulgaris.
Innate and learned aspects of vole urine UV‐reflectance use in the hunting behaviour of the common kestrel Falco tinnunculus
Authors: Zampiga Eleonora , Gaibani Giorgia , Csermely Davide , Frey Hans , Hoi Herbert
Published: June 2006

Some birds are known to use the UV reflectance in their feeding strategy. Knowing that the common kestrel Falco tinnunculus is able to recognise vole trails by perceiving the UV reflectance of their scent marks, this study was designed to investigate whether the use of scent marks in the UV range has an innate component, or if it is only acquired with experience. We tested the preference of 44 experienced adult and 49 naïve juvenile common kestrels in four types of arenas: (1) scent‐marked and covered with a UV transmitting filter (UV+SC), (2) scent‐marked and covered with a UV blocking filter (UV‐SC), (3) sprinkled with water and covered with a UV transmitting filter (UV+W), and (4) sprinkled with water and covered with a UV blocking filter (UV‐W). We assessed the birds’ preference by counting the number of visual scans and visits to each arena. The distribution of scans differed from random in both adults and juveniles. The birds scanned the UV+SC arena more often than the others. Since naïve individuals showed the same preference as experienced ones, we hypothesised that the association between vole scent UV reflectance and vole presence has an innate component in the common kestrel. Nevertheless, adults differed from juveniles because they perceived the scented arenas from the water sprinkled ones, in fact, adults scanned the UV‐SC arena more frequently than both UV+W and UV‐W arenas. This result suggests that the ability of detecting UV cues has a learned component.
Speech perception based on spectral peaks versus spectral shape
Authors: Hillenbrand James M. , Houde Robert A. , Gayvert Robert T.
Published: June 2006

This study was designed to measure the relative contributions to speech intelligibility of spectral envelope peaks (including, but not limited to formants) versus the detailed shape of the spectral envelope. The problem was addressed by asking listeners to identify sentences and nonsense syllables that were generated by two structurally identical source-filter synthesizers, one of which constructs the filter function based on the detailed spectral envelope shape while the other constructs the filter function using a purposely coarse estimate that is based entirely on the distribution of peaks in the envelope. Viewed in the broadest terms the results showed that nearly as much speech information is conveyed by the peaks-only method as by the detail-preserving method. Just as clearly, however, every test showed some measurable advantage for spectral detail, although the differences were not large in absolute terms.
Monaural and binaural loudness of 5- and 200-ms tones in normal and impaired hearing
Authors: Whilby Shani , Florentine Mary , Wagner Eva , Marozeau Jeremy
Published: June 2006

The difference in level required to match monaural and binaural loudness of 5- and 200-ms tones was measured for listeners with normal and impaired hearing. Stimuli were 1-kHz tones presented at levels ranging from 10 to 90dB sensation level. Sixteen listeners (eight normal and eight with losses of primarily cochlear origin) made loudness matches between equal-duration monaural and binaural tones using an adaptive 2AFC procedure. The present results corroborate existing data for 200-ms tones in normal listeners and provide new data for 5-ms tones. On average, the binaural level difference required for equal loudness of monaural and binaural tones is about the same for 5- and 200-ms tones of equal level and changes as a function of level. The group data for normal and impaired listeners are in reasonable agreement with data in the literature. However, the data from some of the impaired listeners deviate markedly from the average, indicating that group data do not accurately represent the behavior of all impaired listeners. Derived loudness functions from the loudness-matching data are reasonably consistent with individual data in the literature.
Expressions for direct evaluation of wave number in cylindrical shell vibration studies using the Flügge equations of motion
Authors: Karczub Denis G.
Published: June 2006

Algebraic expressions for direct evaluation of structural wave number in cylindrical shells are presented for vibration described by the Flügge equations of motion. Applications of the expressions presented here include the evaluation of nondimensional correlation ratios for the estimation of dynamic stress from vibration velocity, and the development of more accurate transmission loss calculations.
Comments on “Intraspecific and geographic variation of West Indian manatee (Trichechus manatus spp.) vocalizations” [J. Acoust. Soc. Am. 114, 66–69 (2003)]
Authors: Sousa-Lima Renata S.
Published: June 2006

This letter concerns the paper “Intraspecific and geographic variation of West Indian manatee (Trichechus manatus spp.) vocalizations” [Nowacek et al., J. Acoust. Soc. Am. 114, 66–69 (2003)]. The purpose here is to correct the fundamental frequency range and information on intraindividual variation in the vocalizations of Amazonian manatees reported by Nowacek et al. (2003) in citing the paper “Signature information and individual recognition in the isolation calls of Amazonian manatees, Trichechus inunguis (Mammalia: Sirenia)” [Sousa-Lima et al., Anim. Behav. 63, 301–310 (2002)].
Investigation of a three-phase medium with a negative parameter of nonlinearity
Authors: Trivett D. H. , Pincon Hervé , Rogers Peter H.
Published: June 2006

Nonlinear acoustic properties of a composite medium, consisting of hollow microspheres suspended in Castor Oil, at elevated hydrostatic pressure are experimentally investigated. The acoustic nonlinear parameter B∕A of the medium is found to be highly dependent upon hydrostatic pressure. B∕A varies from a small negative value near ambient pressure to a very large negative value (around −6000) in the vicinity of 7×104 Pascals, above ambient pressure. With a further increase in hydrostatic pressure the magnitude of B∕A decreases passing through zero and finally becomes positive. Finite amplitude wave propagation in this medium at low hydrostatic pressures is characterized by waveform steepening in the backward direction leading to rarefactive shockwaves and, at high hydrostatic pressures, by steepening in the forward direction leading to compressive shockwaves. Estimates of B∕A are obtained from both the measurement of thermodynamic properties and from waveform distortion during propagation.
Strong on-axis focal shift and its nonlinear variation in low-Fresnel-number ultrasound beams
Authors: Makov Y. N. , Espinosa V. , Sánchez-Morcillo V. J. , Ramis J. , Cruañes J. , Camarena F.
Published: June 2006

We examine the case of focusing transducers with a strong initial (in linear regime) shift of the main on-axis peak pressure maximum from the geometrical focal point toward the transducer. Such transducers are characterized, using the concepts introduced in this paper, by a low Fresnel number. The displacement of this initially shifted on-axis pressure maximum point toward the geometrical focus, and its backward motion as the driving transducer voltage increases until highly nonlinear regimes, has been experimentally observed. The simultaneous monitoring of the temporal wave-form distortion determines the real roles and interplay between different nonlinear effects (refraction and attenuation) in the observed dynamics of the on-axis pressure maximum. The numerical solution of the corresponding mathematical model confirms the physical interpretation of the observed phenomenon.
Bulk conical and surface helical acoustic waves in transversely isotropic cylinders; application to the stiffness tensor measurement
Authors: Perton M. , Audoin B. , Pan Y. D. , Rossignol C.
Published: June 2006

A point-source-point-receiver technique, based on laser generation and laser detection of acoustic waves, allows determination of mechanical properties of anisotropic cylinders. The anisotropic nature of the material and the geometry of the samples make the acoustic signature difficult to interpret. In addition to multiple surface waves, quasi-longitudinal and quasi-shear bulk waves are diffracted and acoustic rays are reflected with or without mode conversion at the cylinder surface. Moreover both bulk and surface diffracted waves have a dispersive behavior. To bypass the intricacies, wave fronts are synthesized with signals provided by scanning a straight line on the cylinder with the laser point source. Conical waves propagating in the volume and helical waves propagating along the surface are then numerically produced. The recovery of the stiffness-tensor components is based on the inversion of the bulk waves, phase velocities. The method is presented and applied to signals simulated or experimentally recorded for a composite material. The five independent stiffness coefficients of the hexagonal symmetry are thus measured with waveforms provided by a single scan along the cylinder surface. The method provides a unique mean for the noncontact measurement of elastic properties of cylindrical parts.
On the sound absorption of quadratic residue diffuser groups with various shapes and combinations
Authors: Yang Jianbin , Shen Yong , Wang Han
Published: June 2006

Quadratic residue diffuser (QRD) groups are used to form a large diffusion surface and extra sound absorption is introduced. In this paper we discuss how the installation pattern of QRD groups affects the sound absorption. The absorption coefficients of QRD in groups with different shapes and combinations were measured in a reverberation room. Notable variations in absorption were observed when the shapes of QRD groups change, especially at the low frequency range below the design frequency of QRD. Two peaks of absorption are observed. When a certain shape is chosen, the detailed combinations of QRDs cause little change in absorption.
Stochastic inversion in acoustic scattering
Authors: Faverjon Beatrice , Ghanem Roger
Published: June 2006

A novel approach is presented for the probabilistic characterization of the solution in inverse acoustic scattering problems. The approach consists of representing the unknown parameters of the scatterer as stochastic processes with spatially random fluctuations. The stochastic processes are represented by their polynomial chaos decomposition. The deterministic coefficients in this parametrization are then computed by solving a deterministic optimization algorithm with an appropriate objective function that captures the probabilistic significance of these coefficients. The general procedure is demonstrated by its application to a two-dimensional problem with the hidden object, a hard obstacle, being immersed in a heterogeneous medium. The formulation provides, as well, a measure of validity of a particular predictive model at matching experimental evidence.
A jury study of noise isolation between condo units incorporating QuietZone® acoustic wall framing in the common wall
Authors: Godfrey Dick , Alter Harry , Berdan Clarke
Published: June 2006

Two identical side-by-side two-story condo units with basements were built in the newly built Owens Corning Building Science and Innovation Center. These units incorporated modern features such as multistory great rooms with adjoining kitchens. Home offices, bedrooms, and basements were located on opposite sides of the common wall. It is common practice to use double-stud walls between adjacent units in multifamily construction. It is also good practice to have a noncontiguous floor plate between units. Instead of a double-stud wall, these units incorporated QuietZone■ acoustic wall framing (resilient stud), and other Owens Corning recommended noise control measures. The wall transmission loss characteristics were measured in the field and in the laboratory. A laboratory jury study was conducted to investigate the adequacy of perceived noise isolation between the units for various source and background noise types and levels.
Predictions of speech quality under conditions of noise and distortion
Authors: Kates James , Arehart Kathryn , Harvey Lewis , Anderson Melinda
Published: June 2006

Noise and distortion reduce speech intelligibility and quality in audio devices such as hearing aids. The purpose of this study is to quantify and model the effects of signal degradation on the perception of speech quality in normal-hearing and hearing-impaired listeners. The stimuli were sentences subjected to eight different levels of additive noise, peak clipping, and center clipping distortion. The subjects listened to all possible comparisons of pairs of the 24 degraded sentences, and for each comparison indicated their preference. Multi-dimensional analysis is used to model the subject decision spaces, and the data are also modeled using a one-dimensional metric to predict the subject quality judgments. The one-dimensional metric is an extension of the procedure developed by Kates and Arehart [J. Acoust. Soc. Am. 117, 2224–2237 (2005)] to model speech intelligibility. That approach is based on dividing the speech signal into three amplitude regions, computing the coherence for each region, and then combining the three coherence values across frequency in a calculation based on the speech intelligibility index (SII). The one-dimensional and multi-dimensional analyses are able to accurately model the quality perception of both normal-hearing and hearing-impaired listeners. [Work supported by GN ReSound and Centers for Disease Control.]
Volitional hyperventilation during ramp exercise to exhaustion
Authors: Walsh Michael L , Takeda Chiyo , Takahashi Aya , Ikeda Yuri , Endo Masako , Miura Akira , Kan Akira , Fukuba Yoshiyuki
Published: June 2006

The purpose of this study was to determine whether volitional hyperventilation at 20 L·min-1above normal exercise values affected exercise duration while performing ramp exercise to exhaustion. Nine healthy subjects performed a ramp exercise test to exhaustion. On a subsequent test they hyperventilated, with the aid of visual and audio feedback, at 20 L·min-1greater than their initial test. Ramp exercise time to exhaustion was substantially reduced from 771.6 ± 85.2 s to 726.6 ± 86.6 s (p < 0.002) with the additional hyperventilation. Subjects underwent 2 more ramp exercise tests and performed a 5 s maximum voluntary ventilation or a forced vital capacity test at work rates corresponding to rest, below lactate threshold (LT), above LT, immediately after exercise, and 3 min recovery. Generally, the flow rates were not affected by exercise below LT and were enhanced during above-LT exercise, exhaustion, and recovery. This indicated a change in pulmonary function that is dependent on exercise intensity. In spite of this increased ability to generate high flow rates, exercise performance was diminished when respiratory muscle work was increased volitionally by 20 L·min-1, indicating a strong coupling between respiratory muscle work and fatigue during ramp exercise in normal subjects.Key words: ventilation, fatigue, pulmonary function, MVV, FVC.
SYNTHESIS AND PIXE CHARACTERIZATION OF CuInSe2 AND CuIn3Se5
Authors: MALAR P. , RAUTRAY TAPASH RANJAN , VIJAYAN V. , KASIVISWANATHAN S.
Published: June 2006

Polycrystalline ingots of CuInSe 2 and CuIn 3 Se 5 were synthesized by melt-quench technique starting from the stoichiometric mixture of constituent elements. X-ray Diffraction (XRD) studies confirmed the single-phase nature of the materials. Compositional analysis by Particle Induced X-ray Emission (PIXE) showed that the compounds are near stoichiometric. Thin films of CuInSe 2 and CuIn 3 Se 5 were grown from pre-synthesized CuInSe 2 and CuIn 3 Se 5 powders. The films were polycrystalline, single-phase and near stoichiometric in nature, as indicated by Transmission Electron Microscopy (TEM) and PIXE studies.
BISMUTH CONTENT OF ELECTRUM FROM MONGOLIAN ARTISANAL/SMALL-SCALE MINING SITES
Authors: MURAO S. , NAITO K. , HAMASAKI S. , SIE S. H. , DEJIDMAA G.
Published: June 2006

Bismuth ( Bi ) content of electrum from Mongolian artisanal/small-scale mining sites was determined by micro-PIXE at CSIRO. This is to provide artisanal/small-scale miners information on the valuable trace element in electrum which they recover from quartz veins. The analysis was done using a 3 MeV micro-beam (30 micrometer in diameter) with an aluminum filter of 125 micrometer thickness. The result showed that electrum grains from the study area contains Bi with a range from 0 to 2,530 ppm.
MATRIX TECHNIQUE REPRESENTATION FOR SECOND RETURN TIME ASYMPTOTICS
Authors: CHAUMOÎTRE VINCENT
Published: June 2006

We answer to questions about n-tuple of return time limit laws raised in [2]. By constructing rank-one systems with a 2-tuple different from (F,F) along sequence of cylinders, we prove that the second return time limit law is not entirely determined by the first return time limit law. Matrix technique is developed in order to solve the combinatorial problem of 2-tuple return time laws. Thus, using a good implementation of a sequence of periodic systems in a rank-one system, examples of rank-one systems such that the 2-tuple return time limit laws along sequences of cylinders satisfies [Formula: see text] are given.
ORE EXTENSIONS SATISFYING A POLYNOMIAL IDENTITY
Authors: LEROY ANDRÉ , MATCZUK JERZY
Published: June 2006

Necessary and sufficient conditions for an Ore extension S = R[x;σ,δ] to be a PI ring are given in the case σ is an injective endomorphism of a semiprime ring R satisfying the ACC on annihilators. Also, for an arbitrary endomorphism τ of R, a characterization of Ore extensions R[x;τ] which are PI rings is given, provided the coefficient ring R is noetherian.
Influence of growth interruption on the formation of solid-state interfaces
Authors: Busch I. , Stümpel J. , Krumrey M.
Published: June 2006

In this study, the effects of growth interruptions on the formation of the interfaces in GaAs∕AlAs multilayers are investigated. For that purpose, a series of different samples has been manufactured with molecular-beam epitaxy. The introduction of growth interruptions of 50 s after the deposition of the layer leads to a change in the morphological properties of the interfaces, in particular their correlation length. These modifications due to the growth interrupt are analyzed with diffuse X-ray scattering. As a result of the measurements, an extension of the lateral correlation length can be proved. By contrast, the vertical correlation of the interfaces is not affected.
Quantitative Rietveld analysis of hydrated cementitious systems
Authors: Mitchell L. D. , Margeson J. C. , Whitfield P. S.
Published: June 2006

A study examining the feasibility, and possible necessity, of using transmission data from capillary mounted samples for quantitative analysis of hydrated cement systems was conducted. In order to obtain true quantitative results, the amorphous contents were determined by the addition of an internal standard. The amorphous content of the starting tricalcium silicate was found to be approximately 21–22 wt %, in close agreement with previously published results. The study revealed that the spherical harmonics preferential orientation correction may not be reliable with unmicronized hydrated cement materials in reflection geometry, as chemically unreasonable progressions in Portlandite content with time were observed. The data obtained from capillary measurements, however, exhibited little or no preferential orientation, and appeared to produce the progression of phase contents expected from the reaction. The use of capillaries would appear to be justified in some circumstances to obtain reliable quantitative results from hydrated cementitious materials. In this particular system, a significant fraction of calcium carbonate was present as aragonite, as well as the more usual calcite.
Electric field influence on emission of characteristic X-ray from Al2O3 targets bombarded by slow Xe+ ions
Authors: Rao J. C. , Song M. , Mitsuishi K. , Takeguchi M. , Furuya K.
Published: June 2006

Low energy characteristic X-ray emission from Al2O3 monocrystalline specimens is measured under bombardment of 100 keV Xe+ ions. The electric field influence on emission of the X-rays of constitute elements in the specimens was investigated. The energy dispersive X-ray spectroscopy spectra show that the characteristic X-ray of Al-Kα seems to be depressed by the applied dc voltages, while the peak intensity of O-Kα was not notably influenced. The O-Kα peaks were broadened and the total counts increased as a higher dc bias was applied. It is possible that a dc electric field parallel to the target surface may influence the X-ray emission from it under ion bombardment.
Iran: Tricontinental Nexus for Y-Chromosome Driven Migration
Authors: Regueiro M. , Cadenas A.M. , Gayden T. , Underhill P.A. , Herrera R.J.
Published: June 2006

Due to its pivotal geographic position, present day Iran likely served as a gateway of reciprocal human movements. However, the extent to which the deserts within the Iranian plateau and the mountain ranges surrounding Persia inhibited gene flow via this corridor remains uncertain. In order to assess the magnitude of this region’s role as a nexus for Africa, Asia and Europe in human migrations, high-resolution Y-chromosome analyses were performed on 150 Iranian males. Haplogroup data were subsequently compared to regional populations characterized at similar phylogenetic levels. The Iranians display considerable haplogroup diversity consistent with patterns observed in populations of the Middle East overall, reinforcing the notion of Persia as a venue for human disseminations. Admixture analyses of geographically targeted, regional populations along the latitudinal corridor spanning from Anatolia to the Indus Valley demonstrated contributions to Persia from both the east and west. However, significant differences were uncovered upon stratification of the gene donors, including higher proportions from central east and southeast Turkey as compared to Pakistan. In addition to the modulating effects of geographic obstacles, culturally mediated amalgamations consistent with the diverse spectrum of a variety of historical empires may account for the distribution of haplogroups and lineages observed. Our study of high-resolution Y-chromosome genotyping allowed for an in-depth analysis unattained in previous studies of the area, revealing important migratory and demographic events that shaped the contemporary genetic landscape.
The Origin and Dispersion Characteristics of the Observed Tropical Summertime Synoptic-Scale Waves over the Western Pacific*
Authors: Tam Chi-Yung , Li Tim
Published: June 2006

The origin, initiation, and dispersion behavior of the observed summertime synoptic-scale disturbances in the tropical western Pacific are studied. These westward-propagating disturbances have the strongest growth rate over the region of ∼130°–160°E off the equator. The three-dimensional wave activity flux associated with a wave packet in the vicinity of this region is computed. In general, wave activity is directed westward. There is accumulation of activity flux, which gives rise to the amplification of waves. In the low levels, such accumulation can be attributed to the convergence of both the mean flow and the intrinsic group velocity. Diabatic forcing also contributes to the growth of disturbances and is most important in the 500–600-hPa layer. Along the east–west-oriented “storm tracks” of the synoptic-scale disturbances, there are two different dynamical regimes. West of ∼150°E, enhanced convection is associated with increased specific humidity at the top of the planetary boundary layer and is in phase with positive low-level vorticity anomalies. To the east of 150°E the vorticity leads the convection by about one-quarter of a wavelength. This phase relationship can be explained by adiabatic dynamics and is related to the positive vertical shear of the mean zonal flow in the latter region.

Near and to the east of the date line where disturbances are initiated in the low levels, the heat flux associated with the synoptic-scale eddies is negative (i.e., υ′T ′ < 0) from about 300 to 700 hPa. This implies downward-directed wave activity. In the upper troposphere at the same geographical location, there is southward wave activity from the extratropics penetrating into the Tropics. These findings suggest that summertime synoptic-scale disturbances may originate from extratropical forcing. This hypothesis is supported by a case study. Intrusion of high potential vorticity into the Tropics was seen to be followed by downward development, resulting in low-level disturbances that subsequently moved westward in the western Pacific and grew.
Traumatic Spinal Cord Injuries from Snowboarding
Authors: Wakahara Kazuhiko , Matsumoto Kazu , Sumi Hiroshi , Sumi Yasuhiko , Shimizu Katsuji
Published: June 2006

Background

Little information has yet been made available on the types and mechanisms of snowboard-related spinal cord injuries or their neurologic involvement.

Purpose

To review the cause and types of spinal cord injuries seen in snowboarders.

Study Design

Case series; Level of evidence, 4.

Methods

The subjects were 18 patients (mean age, 24.0 years) referred to the authors’ institution for neurologic deficits associated with spinal injuries between November 1, 1995, and April 9, 2005. The clinical features of these patients were reviewed with respect to epidemiologic factors, mechanism of injury, fracture pattern, and neurologic status.

Results

The 18 snowboarders with spinal cord injuries constituted a very homogeneous group. First, almost all patients (94.4%) were young men. Second, most of the patients were intermediate or expert boarders. Third, the most common cause of injury was a failure of intentional jumping (83.3%). Fourth, the most commonly affected site was the thoracolumbar junction (66.7%), and the most common type of fracture was an anterior dislocation fracture (66.7%). Finally, in the thoracolumbar group, most patients (83.3%) were classed as Frankel grade A or B.

Conclusion

It is fundamentally important that snowboarders, especially young men, be made aware of the spinal injury risk associated with jumping.
Si–H and Si–C Bond Activation of a Triorganosilane Promoted by [RhCl{P(i-Pr)3}2]. Synthesis and Structure of a Dinuclear Rh(IV) Complex with μ-Silylene Ligands
Authors: Osakada Kohtaro , Koizumi Take-aki , Yamamoto Takakazu
Published: June 2006

[RhClL2] (L = P(i-Pr)3) reacts with tris(2-phenylethyl)silane in pentane to give a dinuclear Rh(IV) complex, [LRh(H)2{μ-Si(CH2CH2Ph)2}2Rh(H)2L] (1), and several organic products including ethylbenzene, chloro{tris(2-phenylethyl)}silane, and tetrakis(2-phenylethyl)silane. Results of X-ray crystallography and NMR study of 1 indicate a symmetrical molecular structure containing two Rh(IV) centers which are bonded to each other through two bridging silylene ligands. [1, triclinic, space group with a = 12.886(4), b = 13.217(3), c = 10.388(3) Å, α = 104.78(2), β = 106.50(2), γ = 61.70(2)°, V = 1478 Å3, Z = 1, R = 0.073, Rw = 0.081 for 3930 reflections with I > 3σ(I) and 289 variables]. The initial reaction products contain mononuclear Rh(III) complexes, [RhCl(H)2L2] (2) and [RhCl(H) {Si(CH2CH2Ph)3}L2] (3), the latter of which is turned into 1 on further stirring. Reactions of tribenzylsilane and of tris(p-methylbenzyl)silane with [RhClL2] cause immediate separation of [RhL(R3Si)H(μ-Cl)2RhH(SiR3)L] (4: R = CH2Ph, 5: R = CH2C6H4Me-p). X-Ray crystallography of 4 has revealed the structure containing two Rh(III) centers with distorted trigonal bipyramidal coordination [4, monoclinic, space group P21/n with a = 11.513(3), b = 28.227(9), c = 20.883(5) Å, β = 94.14(2)°, V = 6769 Å3, Z = 4, R = 0.071, Rw = 0.066 for 4249 reflections with I > 3σ(I) and 637 variables]. A prolonged reaction of tribenzylsilane leads to formation of chlorotribenzylsilane.
Magnetic Studies on the Dissociation Equilibria of Dinuclear Nickel(II) Alkanoates in Non-Aqueous Solutions
Authors: Emori Shuji , Hara Toshiaki
Published: June 2006

Dinuclear nickel(II) alkanoates, [Ni2(RCOO)4(quin)2] (R = C2H5CH(CH3)–, C2H5C(CH3)2–, and (C3H7)2CH–; quin = quinoline), were prepared, and then characterized by means of magnetic-susceptibility and IR spectroscopy. The equilibria between the mono- and dinuclear species in mixed acetone–benzene, mixed ethanol–benzene, and mixed tetrahydrofuran–benzene solution are discussed in terms of the donor number of acetone, ethanol, and tetrahydrofuran and in terms of the Ni–O bond strength. By comparing the Ni–O and Cu–O bond strengths, the exchange-coupling strength through the carboxylate bridges between the nickel(II) ions was estimated from that between copper(II) ions.
Large Current Density CO2 Reduction under High Pressure Using Gas Diffusion Electrodes
Authors: Hara Kohjiro , Sakata Tadayoshi
Published: June 2006

Electrochemical reduction of CO2 was studied under high pressure on Co, Rh, Ni, Pd, Pt, Ag, and Cu electrocatalysts supported in the gas diffusion electrode (GDE). CO was produced on Pd and Ag catalysts at faradaic efficiencies of 58 and 86%, respectively, at 300 mA cm−2 under CO2 20 atm. In the case of Cu-GDE, CO and formic acid were produced as the main reduction products. Hydrogen was the predominant reduction product in the electrolyses using other GDEs. Effects of the CO2 pressure, the current density, and the passed charge in the electrochemical reduction of CO2 using Pd and Ag-GDEs were investigated in detail. The maximum partial current density of CO formed on the Pd-GDE under CO220 atm was 450 mA cm−2. A very large partial current density of CO formation of 3.05 A cm−2 was achieved in the electrolysis under 30 atm on the Ag-GDE.
Theoretical Study of Cyclic Isomers of HNOx (x = 2—6)
Authors: Li Yumin , Iwata Suehiro
Published: June 2006

A series of cyclic isomers of HNOx (x = 2—6) are examined with ab initio MO methods. All of these cyclic isomers have a ring comprised of one nitrogen atom and two to five oxygen atoms. They are classified under the following three types. Type A: NOx ring with an exo hydrogen bonded to a nitrogen; type B: NOx ring with an exo OH bonded to a nitrogen, and type C: NOx ring with an exo OOH bonded to a nitrogen. The geometry optimizations are carried out at the HF and MP2 levels of approximation with 6-31G** basis set, and the energies are evaluated at the MP4SDTQ approximation. We have failed to locate a five-membered ring HNOx at the MP2 level. The geometries and vibrational frequencies are discussed by comparing with the data of the related known stable molecules. The conformational preferences among the isomers are interpreted in terms of an intramolecular long-range hydrogen-oxygen interaction.
Bidirectional Inclusion of Free-radical Probe by Water-soluble Calixarene as Detected by Electron Spin Resonance
Authors: Sueishi Yoshimi , Negi Mieko , Kotake Yashige
Published: June 2006

The first detection of bidirectional inclusion by water-soluble calixarene is reported. The free-radical probe α-(2,4,6-trimethoxyphenyl)benzyl tert-butyl nitroxide is shown to produce two isomeric inclusion complexes with p-sulfonatocalix[8]arene in aqueous media, being detected with ESR spectrometry. ESR spectra were assignable to tert-butyl-in and phenyl-in complex and the association constants at room temperature were 131 and 45 mol−1 dm3 for tert-butyl-in and phenyl-in, respectively.
Solvolysis of Benzyl Alcohols and Ethers in 1,2-Diols and Application to a Deprotection of Benzyl Ether-type Protecting Groups
Authors: Miyake Hideyoshi , Fujimura Masahiro , Tsumura Takatsugu , Sasaki Mitsuru
Published: June 2006

Some kinds of benzyl alcohols and ethers react with 1,2-diols, such as ethylene glycol and propylene glycol, at 130–190 °C to give 2-hydroxyethyl or 2-hydroxypropyl ethers. Application of this reaction to a deprotection of benzyl ether-type protecting groups, under neutral conditions, was also described.
Prediction and observation of cloud processing of the aerosol size distribution by a band of cumulus
Authors: Peter J. R. , Siems S. T. , Jensen J. B. , Gras J. L. , Ishizaka Y. , Hacker J. M.
Published: June 2006

Airborne observations of aerosol processing by a cumulus cloud, obtained during the ACE‐Asia experiment, are presented. Mixing diagrams of conserved variables, wet equivalent potential temperature and total water mixing ratio are used to identify the fraction of cloud‐base air that has combined with environmental air entrained into the cloud. We extend this analysis to deduce the origins of detrained air. Using observations of aerosol spectra obtained from below cloud base, and upwind and downwind of the cumulus band, we predict the shape of the aerosol spectrum in the detrained air and compare it with observations. The results show evidence of size‐dependent scavenging of the aerosol, with up to 20% loss of ultra‐fine (particle radius, rp ≤ 0.003 µm) and fine mode particles 0.006 µm ≤ rp ≤ 0.066 µm) and up to a 40% loss of aerosol in the accumulation mode 0.066 µm ≤ rp ≤ 0.7 µm).

We conclude that coalescence of cloud droplets, even in a mildly precipitating cumulus, can result in a substantial depletion of larger accumulation mode aerosol. The cloud not only caused a general reduction in aerosol concentration, but also substantially modified the aerosol size distribution in the lower free troposphere. This effect may significantly influence the properties of clouds subsequently formed on the detrained aerosol. Copyright © 2006 Royal Meteorological Society.
Conservative constraint for a quasi‐uniform overset grid on the sphere
Authors: Peng Xindong , Xiao Feng , Takahashi Keiko
Published: June 2006

A conservative constraint is presented for a new quasi‐uniform overset (Yin‐Yang) grid on the sphere. The Yin‐Yang grid is a newly developed grid system in spherical geometry created by matching two notched latitude–longitude grids which are normal to each other. Global and local conservation is achieved with an interpolation algorithm that exactly guarantees that the fluxes on boundaries of the two grid components are identical. Several numerical experiments are shown to confirm the conservation in passive transport situations and shallow‐water dynamical equations. Copyright © 2006 Royal Meteorological Society.
Hormone replacement therapy and mammographic screening outcomes in Western Australia
Authors: Crouchley Kathryn , Wylie Elizabeth , Khong Eric
Published: June 2006

Objectives: The study objectives were three-fold: to estimate the effect of hormone replacement therapy (HRT) use on the sensitivity of mammographic screening; to examine the odds of having an interval cancer as a function of duration of HRT use and to compare the size, grade, lymph node and hormone receptor status of tumours for HRT users and non-users.

Setting: Perth, Western Australia, where a free, population-based mammographic screening service targets women aged 50–69 years.

Methods: The cohort consisted of 113,310 women who had 119,296 screening episodes between January 1998 and December 1999. Unconditional logistic regression was used to model the odds of having an interval cancer as a function of the effect of the duration of HRT use (measured in years). Using subsequent screening rounds, χ2-tests were used to examine whether HRT users differed from HRT non-users in terms of tumour characteristics.

Results: Ninety-seven screen-detected and 31 interval cancers were diagnosed among women who were on initial screening rounds, and 393 screen-detected and 153 interval cancers were diagnosed among women on subsequent screens, two years post screening. Two-year sensitivity outcomes were significantly lower for HRT users on initial screening rounds. For women on subsequent screening rounds, the odds of having an interval cancer increased with the duration of HRT use (odds ratio 1.09, 95% confidence interval 1.04–1.14, P<0.04) after controlling for age, family history, tumour grade, size and pathology type. The histopathological characteristics of cancers did not differ for HRT users compared with HRT non-users.

Conclusion: The sensitivity of mammographic screening was reduced and the odds of having an interval cancer were increased for HRT users compared with HRT non-users. For women on subsequent screening episodes, the odds of having an interval cancer increased with duration of HRT use.
Receiver operating characteristics of the prostate specific antigen test in an unselected population
Authors: McLernon David J , Donnan Peter T , Gray Mike , Weller David , Sullivan Frank
Published: June 2006

Objectives: To determine the operating characteristics of prostate-specific antigen (PSA) testing and prostate cancer diagnosis rates in men who have had an initial PSA test in Tayside.

Setting: A retrospective cohort study in Tayside, Scotland from 1992 to 2001.

Methods: In total, 20,623 men were PSA tested during the period 1992–2001. After exclusions, 19,660 were studied. Sensitivity and specificity were calculated for various PSA cut-off values by age group using logistic regression weighted for verification bias (biopsy). Cox regression analysis was performed using six test pattern cohorts.

Results: The annual rate of PSA testing increased from 5.1 per 1000 man years in 1992 to 21.3 per 1000 man years in 2001. The average number of PSA tests per patient increased from 1.11 in 1992 to 2.57 in 2001. Prostate cancer diagnosis and death rates remained constant from 1995 onward. The PSA test had generally inadequate sensitivity and specificity values, so a unique cut-off could not be found for the two older age groups which could be used as a recommendation for biopsy. The commonly used 4 ng/mL cut-off was reasonably sensitive and specific only for the under 60 age group with values of 92.4% and 90.7%, respectively. For prostate cancer diagnosis, the hazard ratios (HR) were reported relative to those with a series of all normal tests. For those with an initially normal PSA test who had at least one abnormal retest result the HR for diagnosis was 10.43 (95% confidence interval [CI] 6.17–17.63). For those with initially abnormal tests with normal retests HR = 1.63 (95% CI 0.65–4.07).

Conclusions: There are no optimal PSA cut-off values for older age groups with which to make a confident referral for biopsy. The increase in PSA testing and the questionable cut-off values of the test calls for the development of an alternative screening strategy.
Development and characterization of dried blood spot materials for the measurement of immunoreactive trypsinogen
Authors: Li Lixia , Zhou Yingtao , Bell Carol J , Earley Marie C , Hannon W Harry , Mei Joanne V
Published: June 2006

Objectives: In response to increasing numbers of states in the US that test newborn babies for cystic fibrosis (CF), the Newborn Screening Quality Assurance Programme initiated a pilot proficiency testing programme for immunoreactive trypsinogen (IRT), the biomarker for CF. Dried blood spot specimens (DBS) were used to evaluate the performance of laboratories that screen babies for CF.

Methods: DBS were prepared from human whole blood enriched with physiologically relevant levels of IRT. Various methods of making IRT-enriched DBS were used to optimize the recovery and stability of the biomarker, including preparation of DBS from either intact or lysed red blood cells, varying the timing of IRT addition to blood before dispensing onto filter paper, adding a protease inhibitor cocktail, and treating serum with charcoal before IRT enrichment. The recovery and stability of IRT in DBS were assessed. Newborn screening laboratories were offered the opportunity to test blind-coded DBS in the pilot PT programme.

Results: IRT was stable in the filter paper matrix when stored for one year at either −20°C or 4°C. Fifty percent more IRT was recovered from DBS prepared with lysed red blood cells where the IRT was added to blood just before dispensing; however, protease inhibitors did not improve IRT recovery.

Conclusions: IRT in the DBS matrix is stable and can be shipped worldwide under ambient conditions. Optimal IRT recovery was achieved by adjustment of DBS production practices. Laboratories receiving specimens accurately measured IRT by a variety of commercial and in-house methods.
Prevalence of G6PD deficiency in newborns in the south of Brazil
Authors: Castro Simone , Weber Raquel , Dadalt Vivian , Tavares Volnei , Giugliani Roberto
Published: June 2006

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked disorder which causes neonatal jaundice in most cases, and in association with intake of drugs or certain foods (for example fava) can cause haemolytic crises. The aim of this study was to determine the prevalence of G6PD deficiency in Rio Grande do Sul (RS), the southernmost state of Brazil. We tested 2799 newborn blood samples. A commercial kit was used for the quantitative measurement of G6PD activity. Of the 2799 samples, 39 (1.4%) exhibited total deficiency, 178 (6.4%) exhibited intermediate deficiency and 2582 (92.2%) were normal. We found no correlation between G6PD deficiency and ethnic origin, but a high prevalence of patients with partial deficiency could be associated with the type of colonization of RS. The combined prevalence for both types of deficiency (complete and partial) was 7.9% among the newborn population. This finding is important as both types of deficiency must receive same kind of preventive care.
Screening for breast cancer in England: past and future
Authors:   Advisory Committee on Breast Cancer Screening
Published: June 2006

• The NHS Breast Screening Programme (NHSBSP) began in 1988. It aims to invite all women aged 50–70 years for mammographic screening once every three years. The programme now screens 1.3 million women each year, about 75% of those invited, and diagnoses about 10,000 breast cancers annually.

• Although some have questioned the value of screening for breast cancer, the scientific evidence demonstrates clearly that regular mammographic screening between the ages of 50 and 70 years reduces mortality from the malignancy.

• Screened women are slightly more likely than unscreened women to be diagnosed with breast cancer. The cancers in screened women are smaller and are less likely to be treated with mastectomy than they would have been if diagnosed without screening.

•For every 400 women screened regularly by the NHSBSP over a 10-year period, one woman fewer will die from breast cancer than would have died without screening.

• The current NHSBSP saves an estimated 1400 lives each year in England.

• The screening programme spends about £3000 for every year of life saved.