bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructural evidence of low‐strain, time‐transgressive subglacial deformation
Authors: Larsen N. K. , Piotrowski J. A. , Menzies J.
Published: February 2007

Microstructural analyses were used to investigate the formation of a macroscale‐massive till at Knud Strand in Denmark. More than 100 thin sections were examined and microstructures mapped and counted for quantitative comparison and interpretation. Microstructures indicative of both brittle (grain lineations, edge‐to‐edge crushed grains) and ductile (turbate structures) deformation are evenly distributed in vertical profiles through the till, suggesting that strain contributed to its formation. Discrete shears (grain lineations and plasmic fabric) probably accommodated most deformation, whereas rotational deformation was less prominent. The microshear geometry fits the predicted Coulomb–Mohr failure criterion, indicating that till behaves as a plastic material. Strain estimate of ca. 101 from micromorphological proxies is two–three orders of magnitude lower than expected if the till was subjected to pervasive deformation. A hybrid of lodgement and time‐transgressive deformation is envisaged as the till‐forming processes. Our data suggest that even abundant evidence of microscale deformation at continuing high levels of strain may only record the latest process of deposition and deformation and therefore not fully reflect the complexity of till genesis. Copyright © 2007 John Wiley & Sons, Ltd.
Molecular cytogenetic characterisation of an interstitial deletion 12p detected by prenatal diagnosis
Authors: Stumm Markus , Klopocki Eva , Gasiorek‐Wiens Adam , Knoll Ute , Wirjadi Deni , Sarioglu Nanette , Wegner Rolf‐Dieter , Tönnies Holger
Published: February 2007

Objectives

Deletions in the short arm of chromosome 12 are rare structural aberrations. Till now only ten patients with interstitial deletions are described in the literature. Here, we report on the first case detected by prenatal diagnosis. Chorionic villi sampling was performed in the 14th week of gestation, indicated by fetal abnormalities detected by ultrasound examination. Conventional cytogenetic and molecular cytogenetic techniques were applied to determine the correct karyotype of the affected fetus.

Results

Analysing Giemsa‐ and QFQ‐stained chromosomes of the CVS short‐term culture, a structural aberrant chromosome 12 was detected. Fluorescence in situ hybridisation with YAC‐probes and CGH analysis with DNA extracted from native chorionic villi proved an interstitial deletion in the aberrant chromosome 12. The GTG‐banded chromosomes of the CVS long‐term culture confirmed these results. Analyses of the parental chromosomal sets yielded normal results, indicating a de novo aberration. Array CGH analysis was performed to determine accurately the deletion breakpoints. Finally, according to ISCN 2005, the karyotype could be determined as 46,XX.arr cgh 12p13.2p11.21(RP11‐77I22→RP11‐144O23)× 1.

Conclusion

The presented case shows the power of modern cytogenetic methods, allowing a more detailed diagnosis in affected individuals, and therefore, facilitating a more reliable prenatal diagnosis. Copyright © 2007 John Wiley & Sons, Ltd.
Infrared thermographic analysis on copolymerization of spiroorthoester with oxetane
Authors: Nagasawa Tomomi , Ochiai Bungo , Endo Takeshi
Published: February 2007

Infrared (IR) thermography was employed to monitor temperature changes during the copolymerization of a spiroorthoester monomer with an oxetane monomer initiated with a benzyl sulfonium salt. The temperature changes in the polymerizations decreased with the increase of the initial feed ratios of the spiroorthocarbonate monomer. For instance, the temperature in the copolymerization of the equimolar mixture of both of the monomers increased only ∼1 °C, whereas that in the homopolymerization of the oxetane monomer increased more than 20 °C. This result indicates that the copolymerization employing spiroorthocarbonate monomers effectively suppress temperature increase, which are responsible to shrinkage during cooling. The suppression of polymerization shrinkage by spiroorthocarbonate was also confirmed by density measurement of the polymers using a gas pycnometer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1388–1393, 2007.
Cooperative propagation of local stability changes from low‐stability and high‐stability regions in a SH3 domain
Authors: Casares Salvador , López‐Mayorga Obdulio , Vega M. Cristina , Cámara‐Artigas Ana , Conejero‐Lara Francisco
Published: February 2007

Site‐directed mutagenesis has been used to produce local stability changes at two regions of the binding site surface of the α‐spectrin SH3 domain (Spc‐SH3) differing in their intrinsic stability. Mutations were made at residue 56, located at the solvent‐exposed side of the short 310 helix, and at residue 21 in the tip of the flexible RT‐loop. NMR chemical‐shift analysis and X‐ray crystallography indicated negligible changes produced by the mutations in the native structure limited to subtle rearrangements near the mutated residue and at flexible loops. Additionally, mutations do not alter importantly the SH3 binding site structure, although produce significant changes in its affinity for a proline‐rich decapeptide. The changes in global stability measured by differential scanning calorimetry are consistent the local energy changes predicted by theoretical models, with the most significant effects observed for the Ala‐Gly mutations. Propagation of the local stability changes throughout the domain structure has been studied at a per‐residue level of resolution by NMR‐detected amide hydrogen–deuterium exchange (HX). Stability propagation is remarkably efficient in this small domain, apparently due to its intrinsically low stability. Nevertheless, the HX‐core of the domain is not fully cooperative, indicating the existence of co‐operative subunits within the core, which is markedly polarized. An equilibrium ϕ‐analysis of the changes in the apparent Gibbs energies of HX per residue produced by the mutations has allowed us to characterize structurally the conformational states leading to HX. Some of these states resemble notably the folding transition state of the Spc‐SH3 domain, suggesting a great potential of this approach to explore the folding energy landscape of proteins. An energy perturbation propagates more effectively from a flexible region to the core than in the opposite direction, because the former affects a broader region of the energy landscape than the latter. This might be of importance in understanding the special thermodynamic signature of the SH3‐peptide interaction and the relevance of the dual character of SH3 binding sites. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Empirical measurement of sustainable welfare from the perspective of extended genuine savings
Authors: Lin Grace T. R.
Published: February 2007

The original genuine savings (GS) model started from a concern mainly with unchanged capital: if the stocks of all forms of capital decline through time, welfare will decline, too, eventually leading to unsustainability. In other words, negative GS rates indicate unsustainability. In the context of sustainable development evaluation, however, income distribution and change ofper capitawelfare are two significant dimensions that the GS model has totally ignored and that need to be aptly incorporated into the model. This is because, behind a positive GS ratio, a country still faces other factors such as current income inequality and population growth, which may undermine the enjoyable sustainable welfare. This paper therefore adjusts the GS framework for these reflections and tests its application to the United Kingdom and Taiwan between 1970 and 1998. Our result shows that the United Kingdom has more depressed GS rates and more eminent sustainable welfare loss than Taiwan over the years. This result has been accordant with some prior research claims: many resource‐rich countries have achieved slow or no long‐term improvements in their standards of living. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Release of data from an ongoing randomized clinical trial for sample size adjustment or planning
Authors: Freidlin Boris , Korn Edward L.
Published: February 2007

The determination of an appropriate sample size is a key issue in planning and designing randomized clinical trials. In settings with time‐to‐event or binary outcomes, the required sample size depends on the control‐arm event (response) rate. An accurate estimate of this rate is not often available at the planning stage. Therefore, non‐comparative control‐arm or pooled‐arm event rates from an ongoing trial are sometimes released for sample size adjustment or planning purposes. It is shown that such non‐comparative data release may still contain information on the relative treatment benefit and may thus adversely affect the ongoing trial. A simple approach to minimizing the effect of the data release is suggested. Published in 2007 by John Wiley & Sons, Ltd.
Comparison of rectus femoris transposition with traditional transfer for treatment of stiff knee gait in patients with cerebral palsy
Authors: Hemo Yoram , Aiona Michael D. , Pierce Rosemary A. , Dorociak Robin , Sussman Michael D.
Published: February 2007

Purpose

To assess the outcome of children with cerebral palsy following reposition of the distal rectus femoris tendon for treatment of stiff knee gait.

Methods

Children with cerebral palsy with stiff knee gait who underwent rectus femoris transfer were studied retrospectively. Inclusion criteria were cerebral palsy of diplegic or quadriplegic type, preoperative and 1 year postoperative three-dimensional motion analysis, and no other surgery except rectus femoris transfer at the time of study. The patients were separated into two groups: in group I, the rectus femoris was transferred to the distal medial hamstring tendons, either the gracilis or the semitendinosus; in group II, the distal tendon of the rectus femoris was transposed laterally and attached to the iliotibial band/intermuscular septum.

Results

Peak knee flexion during swing phase, total dynamic knee range of motion, knee range of motion during swing phase, and time to peak knee flexion during swing phase were all improved in both groups. Hip and pelvic kinematics were not influenced by the surgery. Velocity, stride length, and cadence were all improved following the surgery. There was no difference between the transfer group and the transposition group.

Conclusion

These findings suggest that distal transfer of the rectus femoris is effective in improving swing phase knee function by diminishing the mechanical effect of the dysphasic swing phase activity of the rectus femoris, not by converting the rectus femoris to an active knee flexor.
The impact of climate change on sugarbeet yield in the UK: 1976–2004
Authors: JAGGARD K. W. , QI A. , SEMENOV M. A.
Published: February 2007

Since the 1970s, the delivered sugar yield per hectare has risen at an average annual rate of 0·111 t/ha, while the sugar yield in the official variety trials has increased at an average annual rate of 0·204 t/ha. These increases are usually considered to be the result of improvements in varieties and in beet agronomy. The present paper considers the possible impact of recent changes in climate on UK sugar yields by using the Broom's Barn Crop Growth Model and daily weather data collected over the last 30 years. Simulations of sugar yield using weather in eastern England since 1976 increased by an average annual rate of 0·139 t/ha, which accounted for about two thirds of the rate in the official variety trials. This increase was not an artefact of the accuracy of weather recording but it was, in part, accounted for by the trend to earlier sowing. Although it was not statistically significant, the earlier sowing trend was associated with an increase of 0·025 t/ha per year and was an indirect effect of the climate change. The annual deviations from these trends have not tended to become significantly bigger or smaller over the three decades. The model is not variety-specific, so it makes no allowance for variety improvements during the last 30 years. Clearly, varieties have improved so the implication must be that some of the changes in agronomy have tended to decrease the yields significantly. The changes in agronomic practice most likely to be responsible are the extension of the crop processing campaign, leading to greater post-harvest storage losses, and a decrease in the irrigated area.
Pigmentation, impression hardness and the presence of melanosomes in bovine claw tissue
Authors: HEPBURN N. L. , KINNINMONTH L. , GALBRAITH H.
Published: February 2007

The physical properties of hardness and dry matter and the histological characteristics of dermal and epidermal tissues were investigated in lateral and medial claws obtained post mortem from mature crossbred female cattle. Claws containing pigmented (n=22) or non-pigmented (n=22) coronary wall horn were studied. Impression hardness, measured on the dorsal border of claws, proximo-distal at intervals of 5 mm from the lower perioplic line was shown to increase to the 20 mm lower site. Similarly, in comparison with values for pigmented horn, pooled measurements for non-pigmented horn showed greater hardness from the lower perioplic line to the 40 mm lower site but were not different for subsequent measurements towards the distal edge. Differences in values recorded for sole and heel and for coronary wall horn measured under the distal edge were not different for claws varying in coronary horn pigmentation. The absence of differences in dry matter at measurement sites suggested that differences in impression hardness values were not caused by variation in water content of horn. Histological examination of pigmented claw wall horn and underlying soft tissue showed pigment-containing cells in the coronary epidermis but not coronary dermis or in dermis or epidermis of laminae. Pigmentation appeared concentrated in melanosomes in cells along the basement membrane and was present uniformly throughout the epidermis and in cells lining horn tubules. There was no pigmentation detected in the soft tissue epidermis of claws selected visually for non-pigmented wall horn. The presence of melanosomes in epidermal cells from the pigmented coronary region was demonstrated by electron microscopy. The results suggest that pigmentation in the coronary region is associated with reduced initial development of hardness. The possible antagonism between antioxidant properties of melanins and requirement for an oxidative environment for disulphide bond formation in the cytoskeleton of horn cells is discussed.
Influence of pulse repetition rate on the average size of silicon
nanoparticles deposited by laser ablation
Authors: WANG YING-LONG , XU WEI , ZHOU YANG , CHU LI-ZHI , FU GUANG-SHENG
Published: February 2007

To investigate the influence of pulse repetition rate on the average
size of the nanoparticles, nanocrystalline Si films were prepared by
pulsed laser ablation in high-purity Ar gas with a pressure of 10 Pa at
room temperature, under the pulse repetition rates between 1 and 40 Hz,
using a nanosecond laser. Raman, X-ray diffraction spectra, and scanning
electron microscopy images show that with increasing pulse repetition
rate, the average size of the nanoparticles in the film first decreases
and reach its minimum at 20 Hz, and then increases, which may be
attributed to the nonlinear dynamics of the laser-ablative deposition. In
our experiment conditions, the duration of the ambient restoration, a
characteristic parameter being used to distinguish nonlinear or linear
region, is about a few seconds from the order of magnitude, which is
consistent with the previous experimental observation. More detailed model
to explain quantitively the observed effect is under investigation.
New aspects for fusion energy using inertial confinement
Authors: HORA HEINRICH
Published: February 2007

Magnetic confinement fusion (MCF) based on neutral particle beam irradiation reached the highest gains with JET and is discussed in relation to the ITER project for a possible re-orientation with respect to the ignition process. Ignition plays a similar role for inertial confinement fusion (ICF). After a short review about specific ICF developments, the fast igniter development offered a re-consideration of igniting DT fuel at modest or low compression. The observation of extreme anomalies (Sauerbrey 1996, Zhanget al., 1998 and Badziaket al., 1999) at interaction of picosecond (ps) laser pulses above TW power could be explained as a skin layer mechanism based on earlier computations (Horaet al., 2002) with nonlinear (ponderomotive) force acceleration. The resulting very high ion current density space charge neutral plasma blocks interacting as pistons to ignite DT may lead to a new scheme of laser fusion with low cost energy generation.
Multiply ionized carbon plasmas with index of refraction greater
than one
Authors: FILEVICH J. , GRAVA J. , PURVIS M. , MARCONI M.C. , ROCCA J.J. , NILSEN J. , DUNN J. , JOHNSON W.R.
Published: February 2007

For decades the analysis of interferometry have relied on the
approximation that the index of refraction in plasmas is due solely to the
free electrons. This general assumption makes the index of refraction
always less than one. However, recent soft x-ray laser interferometry
experiments with Aluminum plasmas at wavelengths of 14.7 nm and 13.9 nm
have shown fringes that bend the opposite direction than would be expected
when using that approximation. Analysis of the data demonstrated that this
effect is due to bound electrons that contribute significantly to the
index of refraction of multiply ionized plasmas, and that this should be
encountered in other plasmas at different wavelengths. Recent studies of
Silver and Tin plasmas using a 46.9 nm probe beam generated by a Ne-like
Ar capillary discharge soft-ray laser identified plasmas with an index of
refraction greater than one, as was predicted by computer calculations. In
this paper we present new interferometric results obtained with Carbon
plasmas at 46.9 nm probe wavelength that clearly show plasma regions with
an index of refraction greater than one. Computations suggest that in this
case the phenomenon is due to the dominant contribution of bound electrons
from doubly ionized carbon ions to the index of refraction. The results
reaffirm that bound electrons can strongly influence the index of
refraction of numerous plasmas over a broad range of soft x-ray
wavelengths.
Laser triggered micro-lens for focusing and energy selection of MeV
protons
Authors: WILLI O. , TONCIAN T. , BORGHESI M. , FUCHS J. , D'HUMIÈRES E. , ANTICI P. , AUDEBERT P. , BRAMBRINK E. , CECCHETTI C. , PIPAHL A. , ROMAGNANI L.
Published: February 2007

We present a novel technique for focusing and energy selection of
high-current, MeV proton/ion beams. This method employs a hollow
micro-cylinder that is irradiated at the outer wall by a high intensity,
ultra-short laser pulse. The relativistic electrons produced are injected
through the cylinder's wall, spread evenly on the inner wall surface
of the cylinder, and initiate a hot plasma expansion. A transient radial
electric field (107–1010 V/m) is
associated with the expansion. The transient electrostatic field induces
the focusing and the selection of a narrow band component out of the
broadband poly-energetic energy spectrum of the protons generated from a
separate laser irradiated thin foil target that are directed axially
through the cylinder. The energy selection is tunable by changing the
timing of the two laser pulses. Computer simulations carried out for
similar parameters as used in the experiments explain the working of the
micro-lens.
Investigation of serial coherent laser beam combination based on
Brillouin amplification
Authors: WANG SHUANGYI , LÜ ZHIWEI , LIN DIANYANG , DING LEI , JIANG DONGBIN
Published: February 2007

Based on transferring energy from multiple pump beams into one Stokes
beam using Brillouin amplification, a serial coherent laser beam
combination scheme is presented, which has many advantages, such as,
simple structure, low cost, ease of adjustment, higher load capability,
scalable easily, etc. Furthermore, it has been demonstrated that the
combination of several beams using this method is theoretically possible.
But in practice, the amplification of high power Stokes beam is a key
problem to solve. In this paper, the amplification of Stokes beam whose
power is higher than the pump beam is first studied and proved
experimentally. Coupling the two laser beams by this method is proved
experimentally, and the coupling efficiency reaches more than 80%. Then
the feasibility of multiple beams combination based on Brillouin
amplification is analyzed and tested theoretically.
A study of substrate temperature distribution during ultrashort
laser ablation of bulk copper
Authors: LAM Y.C. , TRAN D.V. , ZHENG H.Y.
Published: February 2007

With the aid of an infrared thermograph technique, we directly
observed the temperature variation across a bulk copper specimen as it was
being ablated by multiple femtosecond laser pulses. Combining the
experimental results with simulations, we quantified the deposited thermal
power into the copper specimen during the femtosecond laser ablation
process. A substantial amount of thermal power (more than 50%) was
deposited in the copper specimen, implying that thermal effect can be
significant in femtosecond laser materials processing in spite of its
ultrashort pulse duration.
Low velocity ion stopping of relevance to the US beam-target
program
Authors: DEUTSCH CLAUDE , POPOFF ROMAIN
Published: February 2007

This article appeared in Volume 24, Number 3, Pages 421–425.
A beef-associated outbreak of Salmonella Typhimurium DT104 in The Netherlands with implications for national and international policy
Authors: KIVI M. , HOFHUIS A. , NOTERMANS D. W. , WANNET W. J. B. , HECK M. E. O. C. , VAN DE GIESSEN A. W. , VAN DUYNHOVEN Y. T. H. P. , STENVERS O. F. J. , BOSMAN A. , VAN PELT W.
Published: February 2007

A ten-fold increase in Salmonella Typhimurium DT104 cases in The Netherlands during September–November 2005 prompted an outbreak investigation. A population-based matched case-control study included 56 cases and 100 controls. Risk factors for infection were consumption of a pre-processed raw beef product (odds ratio 4·2, 95% confidence interval 1·5–12·0) and of food from mobile caterers (odds ratio 4·9, 95% confidence interval 1·1–22·1). Bacterial molecular typing established a link with another DT104 outbreak in Denmark caused by beef from a third European country. The incriminated beef was traced in The Netherlands and sampling yielded DT104 of the outbreak-associated molecular type. We concluded that this outbreak was caused by imported contaminated beef. Consumers should be informed about presence of raw meat in pre-processed food products. Optimal utilization of international networks and testing and traceability of foodstuffs has the potential to prevent foodborne infections.
Bacterial communities inside and in the vicinity of the Chinese Great Wall Station, King George Island, Antarctica
Authors: Xiao Xiang , Li Mingguang , You Ziyong , Wang Fengping
Published: February 2007

Both bacterial culture and molecular approaches were used to investigate the bacterial diversity inside the Chinese Antarctic Great Wall Station and in its adjacent area. Heterotrophic bacteria were isolated from the samples using a direct plating method. γ-Proteobacteria, Actinobacteria, Flavobacteria and Firmicutes were isolated from these samples. In the three water samples, Pseudomonas species were dominant. In soil samples, Flavobacterium, Bacillus or Arthrobacter species dominated. Escherichia coli strains were isolated only in two samples from inside the station. Total cell counts in the six soil samples were semi-quantified by Quantitative Competitive-PCR of the 16S rRNA gene copies. The soil samples contained 105 to 109 cells g−1. Denaturing gradient gel electrophoresis (DGGE) was used further to investigate the bacterial diversity in the soil samples. A wider range of bacterial diversity including α-Proteobacteria, β-Proteobacteria, δ-Proteobacteria, γ-Proteobacteria, Flavobacteria, Actinobacteria and unclassified bacteria was discovered.
Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen
Authors: Gremmen Niek J.M. , van de Vijver Bart , Frenot Yves , Lebouvier Marc
Published: February 2007

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.
GPS as a geodetic tool for geodynamics in northern Victoria Land, Antarctica
Authors: Capra Alessandro , Mancini Francesco , Negusini Monia
Published: February 2007

The VLNDEF (Victoria Land Network for DEFormation control) project started in 1999 with the aim of detecting crustal deformation in Northern Victoria Land (Antarctica) over an area that had never been surveyed by a dense GPS network before. After a brief summary of the Italian geodetic activities carried out since 1991, the paper presents the results obtained from the processing of data collected from 1999 to 2003. In particular, processing strategies were dealt with, in order to produce horizontal and vertical displacement maps through GPS observations. Absolute motions in a global reference frame have been investigated using a double approach, which allowed us to make considerable progress in detecting movements and standardizing the data analysis. The analyses provide absolute horizontal velocities ranging between 17 mm yr−1 and 8 mm yr−1, with greater motions in the northernmost area. The subtraction of the rigid plate motion provides relative displacements, which may contribute to the understanding of neotectonics and geology, whereas the pattern of the vertical crustal motions detected, with average values of +1.3 mm yr−1, is essential to detect the effect of Glacial Isostatic Adjustment (GIA) and other geophysical signals, and to redefine theory and numerical models used without any direct measurements.
New gastropods from the Jurassic of Orville Coast, eastern Ellsworth Land, Antarctica
Authors: Hikuroa Daniel C.H. , Kaim Andrzej
Published: February 2007

The Latady Group (southern Antarctic Peninsula) hosts the most diverse assemblage of Jurassic molluscs from this continent. A new gastropod mollusc, Silberlingiella latadyensis sp. nov. and three forms assigned to Rissoidae, Pseudomelaniidae and Bullinidae from the Middle-Late Jurassic, Bathonian–Kimmeridgian Hauberg Mountains Formation, Ellsworth Land, Antarctic Peninsula are described here. Silberlingiella is transferred to Eustomatidae and is the first confirmed record of this family in the Southern Hemisphere, indicating a much more widespread Jurassic distribution. The Triassic and Jurassic species of Silberlingiella are compared with the coeval European genus Diatinostoma. Eustomatidae is proposed as an ancestral group for Potamididae and Batillariidae. The composition of the gastropod association described herein differs markedly from the only other Antarctic Jurassic fauna from Alexander Island.
Induction of CD40 Expression and Enhancement of Monoclonal Antibody Production on Murine B Cell Hybridomas by Cross‐Linking of IgG Receptors
Authors: Martín‐López Alicia , García‐Camacho Francisco , Belarbi El Hassan , Martínez‐Escobar Sergio , Contreras‐Gómez Antonio , Molina‐Grima Emilio
Published: February 2007

The 55–6 murine B cell hybridoma line not constitutively expressing CD40 was treated with increasing amounts of intact anti‐mouse surface immunoglobulin G antibody (anti‐mIgG) either not preincubated or preincubated for 48 h with lipopolysaccharide (LPS). In vitro, cross‐linking of surface immunoglobulin G (sIgG) with the whole molecule of anti‐IgG antibodies induced the expression of CD69, CD40, and CD19 surface antigens on 55–6 cells. The effect of sIgG ligation was dose‐dependent, and preincubation with LPS enhanced their responsiveness to anti‐mIgG stimulation. The expression of these surface molecules reached the maximum value during the first part of the cell cycle, corresponding to the position of the G1 peak of the DNA distribution. Stimulation of cells with anti‐mIgG did not induce changes either in the number of viable cells or in the fraction of cells undergoing proliferation (mitosis). However, preincubation of 55–6 cells with LPS for 48 h before stimulation with anti‐mIgG increased both the maximum specific growth rate (μmax) and the percentage of cells in the G2/M phase, in comparison with non‐preincubated cells. Moreover, on cells preincubated with LPS prior to anti‐mIgG treatment, specific IgG2a production rate was enhanced significantly compared to that obtained in control cultures. The correlation between the antibody production rate and the amount of IgG that is detectable on the cell surface was analyzed by flow cytometry. A good correlation between secreted and surface IgG was observed, and the results of cell cycle analyses demostrated that the 55–6 hybridoma cell line has a substantially higher sIgG content in G1 phase.
Scattering of long wavelength shear Alfvén waves by a localized density cavity
Authors: Singh Nagendra , Khazanov Igor
Published: February 2007

We demonstrate here, for the first time, that the scattering of a shear Alfvén wave (SAW) having a long perpendicular wavelength (λ⊥), with a localized density cavity, generates perturbations in the field structures like that expected from the radiation pattern of an Alfvén wave resonance cone (AWRC) emitted from localized sources. Such a SAW‐cavity interaction provides a novel mechanism for generating narrow structures of inertial Alfvén waves like those observed from satellites and variously called solitary, kinetic and dispersive Alfvén waves.
Objective classification of historical tropical cyclone intensity
Authors: Chenoweth Michael
Published: February 2007

Preinstrumental records of historical tropical cyclone activity require objective methods for accurately categorizing tropical cyclone intensity. Here wind force terms and damage reports from newspaper accounts in the Lesser Antilles and Jamaica for the period 1795–1879 are compared with wind speed estimates calculated from barometric pressure data. A total of 95 separate barometric pressure readings and colocated simultaneous wind force descriptors and wind‐induced damage reports are compared. The wind speed estimates from barometric pressure data are taken as the most reliable and serve as a standard to compare against other data. Wind‐induced damage reports are used to produce an estimated wind speed range using a modified Fujita scale. Wind force terms are compared with the barometric pressure data to determine if a gale, as used in the contemporary newspapers, is consistent with the modern definition of a gale. Results indicate that the modern definition of a gale (the threshold point separating the classification of a tropical depression from a tropical storm) is equivalent to that in contemporary newspaper accounts. Barometric pressure values are consistent with both reported wind force terms and wind damage on land when the location, speed and direction of movement of the tropical cyclone are determined. Damage reports and derived wind force estimates are consistent with other published results. Biases in ships' logbooks are confirmed and wind force terms of gale strength or greater are identified. These results offer a bridge between the earlier noninstrumental records of tropical cyclones and modern records thereby offering a method of consistently classifying storms in the Caribbean region into tropical depressions, tropical storms, nonmajor and major hurricanes.
Toward the characterization of upper tropospheric clouds using Atmospheric Infrared Sounder and Microwave Limb Sounder observations
Authors: Kahn Brian H. , Eldering Annmarie , Braverman Amy J. , Fetzer Eric J. , Jiang Jonathan H. , Fishbein Evan , Wu Dong L.
Published: February 2007

We estimate the accuracy of cloud top altitude (Z) retrievals from the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit (AMSU) observing suite (ZA) on board the Earth Observing System Aqua platform. We compare ZA with coincident measurements of Z derived from the micropulse lidar and millimeter wave cloud radar at the Atmospheric Radiation Measurement (ARM) program sites of Nauru and Manus islands (ZARM) and the inferred Z from vertically resolved Microwave Limb Sounder (MLS) ice water content (IWC) retrievals. The mean difference in ZA minus ZARM plus or minus one standard deviation ranges from −2.2 to 1.6 km ± 1.0 to 4.2 km for all cases of AIRS effective cloud fraction (fA) > 0.15 at Manus Island using the cloud radar only. The range of mean values results from using different approaches to determine ZARM, day/night differences, and the magnitude of fA; the variation about the mean decreases for increasing values of fA. Analysis of ZARM from the micropulse lidar at Nauru Island for cases restricted to 0.05 ≤ fA ≤ 0.15 indicates a statistically significant improvement in ZA − ZARM over the cloud radar‐derived values at Manus Island. In these cases the ZA − ZARM difference is −1.1 to 2.1 km ± 3.0 to 4.5 km. These results imply that the operational ZA is quantitatively useful for constraining cirrus altitude despite the nominal 45 km horizontal resolution. Mean differences of cloud top pressure (PCLD) inferred from coincident AIRS and MLS ice water content (IWC) retrievals depend upon the method of defining AIRS PCLD (as with the ARM comparisons) over the MLS spatial scale, the peak altitude and maximum value of MLS IWC, and fA. AIRS and MLS yield similar vertical frequency distributions when comparisons are limited to fA > 0.1 and IWC > 1.0 mg m−3. Therefore the agreement depends upon the opacity of the cloud, with decreased agreement for optically tenuous clouds. Further, the mean difference and standard deviation of AIRS and MLS PCLD are highly dependent on the MLS tangent altitude. For MLS tangent altitudes greater than 146 hPa, the strength of the limb technique, the disagreement becomes statistically significant. This implies that AIRS and MLS “agree” in a statistical sense at lower tangent altitudes and “disagree” at higher tangent altitudes. These results provide important insights on upper tropospheric cloudiness as observed by nadir‐viewing AIRS and limb‐viewing MLS.
A multicoral calibration method to approximate a universal equation relating Sr/Ca and growth rate to sea surface temperature
Authors: Goodkin Nathalie F. , Hughen Konrad A. , Cohen Anne L.
Published: February 2007

Combining strontium‐to‐calcium ratios (Sr/Ca) with mean annual growth rates in Bermuda Diploria labyrinthiformis (brain corals) is shown to improve sea surface temperature (SST) calibrations relative to instrumental data. Growth‐corrected Sr/Ca–SST calibrations based on single‐coral colonies over the same calibration interval, however, are found to be poorly suited for application to data from different coral colonies. This raises concerns about the accuracy of SST reconstructions from fossil coral measurements that involve extrapolation beyond the range of values seen during the calibration period. Here we pursue a novel approach to this problem by incorporating data from multiple coral colonies into a single growth‐corrected Sr/Ca–SST calibration equation, effectively expanding the range of modern values constraining the model. The use of a multiple‐colony calibration model for reconstructing SST yields greater precision and accuracy relative to instrumental data than single‐colony models, providing greater confidence for applications to fossil coral samples.
Stress migration phenomenon in narrow copper interconnects
Authors: Suzuki T. , Nakamura T. , Mizushima Y. , Kouno T. , Shiozu M. , Otsuka S. , Hosoda T. , Matsuyama H. , Shono K.
Published: February 2007

Stress migration (SM) behavior in Cu damascene interconnects was investigated in detail using different kinds of test patterns. SM failure was found in narrow lines that are very long, or connecting to a wide line. In the pattern in which narrow lines are connected to wide metal, the failure rate decreased as the narrow metal becomes longer. It was found that the failure rate in minimum 0.14μm wide lines is more than that in 0.2–0.42μm wide lines. The result of the test patterns with different via arrangements clarified that the placing of the vias at the edge of the M1 line plays an important role in the SM phenomenon in narrow copper lines. Failure analysis using scanning transmission electron microscopy revealed voiding beneath the via at the failure points for all test patterns. It is shown that the enhanced failure rate in the minimum wide lines and the via arrangement effect cannot be understood by the previous diffusion mechanism. Based on these results, the effect of the via arrangement close to the edge of the lower lines on SM failure in narrow lines is discussed.
New ladder operators for the monopole harmonics
Authors: Fakhri H. , Dehghani A. , Jafari A.
Published: February 2007

Using the ladder operators shifting the index m of the associated Jacobi functions, for a given n, the monopole harmonics and their corresponding angular momentum operators are, respectively, extracted as the irreducible representation space and generators of su(2) Lie algebra. The indices n and m play the role of principal and azimuthal quantum numbers. By introducing the ladder operators shifting the index n of the same associated Jacobi functions, we also get a new type of the raising and lowering relations which are realized by the operators shifting only the index n of the monopole harmonics. Moreover, other symmetries, including the transformation of the irreducible representation spaces into each other, are derived based on the operators that shift the indices n and m of the monopole harmonics simultaneously and agreeably as well as simultaneously and inversely. Our results are reduced to spherical harmonics by eliminating magnetic charge of the monopole.
Linear impulse response in hot round jets
Authors: Lesshafft Lutz , Huerre Patrick
Published: February 2007

The linear impulse response of axisymmetric jets is examined for a family of variable-temperature profiles typical of the potential core. The influence of jet heating, shear layer thickness, and Reynolds and Mach numbers on the spatiotemporal stability of both axisymmetric and helical modes is investigated. The linear impulse response is retrieved from a numerical solution of the spatial eigenvalue problem, which is derived from the fully compressible equations of motion. Changes in the spatiotemporal stability of heated versus isothermal jets are shown to arise solely from the effect of the baroclinic torque. By considering the full linear impulse response, the competition between jet column modes and shear layer modes is characterized. Jet column modes are only found to occur for axisymmetric disturbances. In thin shear layer jets, the jet column mode is shown to prevail at low group velocities, whereas axisymmetric and helical shear layer modes dominate at high group velocities. The absolute mode of zero group velocity is found to always be of the jet column type. Although only convectively unstable, the maximum growth rates of the shear layer modes greatly exceed those of the jet column modes in thin shear layer jets. In thick shear layer jets, axisymmetric modes of mixed jet column/shear layer type arise. The weakened maximum growth rate of mixed modes accounts for the dominance of helical modes in temporal stability studies of thick shear layer jets.
Massive neutrinos in almost-commutative geometry
Authors: Stephan Christoph A.
Published: February 2007

In the noncommutative formulation of the standard model of particle physics by Chamseddine and Connes [Commun. Math. Phys. 182, 155 (1996), e-print hep-th∕9606001], one of the three generations of fermions has to possess a massless neutrino. [C. P. Martin et al., Phys. Rep. 29, 363 (1998), e-print hep-th-9605001]. This formulation is consistent with neutrino oscillation experiments and the known bounds of the Pontecorvo-Maki-Nakagawa-Sakata matrix (PMNS matrix). But future experiments which may be able to detect neutrino masses directly and high-precision measurements of the PMNS matrix might need massive neutrinos in all three generations. In this paper we present an almost-commutative geometry which allows for a standard model with massive neutrinos in all three generations. This model does not follow in a straightforward way from the version of Chamseddine and Connes since it requires an internal algebra with four summands of matrix algebras, instead of three summands for the model with one massless neutrino.
Heat transfer between parallel plates: An approach based on the linearized Boltzmann equation for a binary mixture of rigid-sphere gases
Authors: Garcia R. D. M. , Siewert C. E.
Published: February 2007

An analytical version of the discrete-ordinates method is used to develop a concise and particularly accurate solution of the heat-transfer problem for a binary gas mixture confined between two parallel plates. The formulation of the problem allows general (specular-diffuse) Maxwell boundary conditions for each of the two types of particles and is based on a form of the linearized Boltzmann equation that incorporates recently established analytical expressions for the relevant rigid-sphere kernels. Numerical results are reported for the density, the temperature, and the heat-flow profiles relative to each species in Ne-Ar and He-Xe mixtures.
Compact retarding-potential Mott polarimeter
Authors: Neufeld D. D. , Aliabadi H. , Dunning F. B.
Published: February 2007

A simple compact retarding-potential Mott polarimeter is described that operates at an electron accelerating voltage of 25kV. With a thorium target the instrument provides efficiencies η [≡Seff2(I∕I0), where Seff is the effective asymmetry (Sherman) function and I∕I0 is the scattering efficiency] of ∼1.3×10−4 which are similar to the best values obtained using earlier Mott polarimeters. The present instrument, however, occupies a much smaller volume and is suitable for a wide range of applications involving angle- and/or energy-resolved polarization measurements.
Boundary conditions for the moving contact line problem
Authors: Ren Weiqing , E Weinan
Published: February 2007

The physical processes near a moving contact line are investigated systematically using molecular dynamics and continuum mechanics. Constitutive relations for the friction force in the contact line region, the fluid-fluid interfacial force, and the stresses in the fluid-solid interfacial region are studied. Verification of force balance demonstrates the importance of the normal stress jump across the contact line region. Effective boundary conditions are derived using force balance. It is found that in the flow regime studied, the deviation of the wall contact angle from the equilibrium contact angle is proportional to the velocity of the contact line. The effective continuum model is solved numerically and the behavior of the apparent contact angle and the wall contact angle is studied. It is found that the fluid-fluid interface near the wall exhibits a universal behavior. The onset of the nonlinear response for the contact line motion is studied within the framework of Blake’s molecular kinetic theory.
First principles study of Mn impurities in PbTiO3 and PbZrO3
Authors: Boonchun Adisak , Smith M. F. , Cherdhirunkorn B. , Limpijumnong Sukit
Published: February 2007

A first principles study of an Mn impurity in PbTiO3 and PbZrO3 has been carried out to determine its favorable location and its electronic and magnetic properties. We find that it is energetically favorable for the Mn atom to substitute for Ti∕Zr (as opposed to substituting for Pb and O or to residing in an interstitial position) under all equilibrium crystal growth conditions. The Mn defect mainly occurs as neutral-charge Mn substitute Ti∕Zr, which has a total electron spin of 3∕2. When no other impurities are present, a small concentration of charged Mn impurities that also form tends to make the sample slightly p type (n type) in oxygen-rich (poor) equilibrium growth conditions.
Development of noncontact spring constant measurement and deflection characterization of piezoelectric devices
Authors: Cho J. H. , Richards R. F. , Bahr D. F. , Richards C. D.
Published: February 2007

This paper reports methods for measuring the spring constant and modeling the deflection of piezoelectric devices. Because this method uses the equivalent electric circuit of the piezoelectric device and deflection with respect to input voltage, it is a noncontact measurement method. Measurements of the spring constant from the equivalent circuit method and force versus deflection measurements are within 3.3% of each other. An equivalent electrical circuit of the piezoelectric device is also used to provide a model of the relationship between frequency and deflection according to input voltage. Input voltage and power with respect to driving frequency are modeled for a constant mechanical deformation. This model gives an estimation of the required input electrical power to piezoelectric devices for many applications. In order to verify the models, experiments are conducted and the models and experimental results show very good agreement.
Recrystallization of tungsten wire for fabrication of sharp and stable nanoprobe and field-emitter tips
Authors: Greiner M. , Kruse P.
Published: February 2007

Atomically sharp tungsten tips made from single crystal tungsten wire are superior to those made from cold-drawn polycrystalline wire but are rarely used due to their high price. We have devised a method of obtaining highly crystalline tungsten wire by recrystallizing cold-drawn wire. The effect of various heat treatments on the wire microstructure was observed using scanning electron microscopy and x-ray diffraction. A dramatic difference in the shapes of tips etched from cold-drawn and recrystallized wires was observed using transmission electron microscopy. The described annealing process is an inexpensive alternative to using single crystal wires.
Charge injection at interfaces between molecularly doped polymer thin films
Authors: Klenkler Richard A. , Xu Gu , Popovic Zoran D. , Graham John F.
Published: February 2007

Charge injection between the active layers in organic semiconducting devices is a key determinant of device function. Accordingly, understanding the effect of intermixing between the layers at these interfaces is of fundamental importance. In this letter, via the use of the time-of-flight method, a comparison is made between the charge injection across discrete versus intermixed interfaces of N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine and 1,1-bis((di-4-tolylamino)phenyl)-cyclohexane doped polycarbonate, semiconducting thin-film layers. No perturbation to the overall charge transport was observed with the discrete interface; however, in contrast the rate of charge transport was clearly reduced through the intermixed interface.