bluuebunny/crossref_metadata_2025 huggingface dataset:
The Psychic Costs of Empathic Engagement: Personal and Demographic Predictors of Genetic Counselor Compassion Fatigue
Authors: Udipi Sharanya , Veach Patricia McCarthy , Kao Juihsien , LeRoy Bonnie S.
Published: August 2008

Empathic connection with one's patients is essential to genetic counselor clinical practice. However, repeatedly engaging with distressed patients may cause compassion fatigue, a phenomenon characterized as feeling overwhelmed by experiencing patients’ suffering. In order to extend findings of an initial qualitative study, we surveyed 222 genetic counselors about their compassion fatigue and factors that predict its occurrence. Multiple regression analysis identified seven significant predictors accounting for 53.7% of the variance in compassion fatigue. Respondents at higher risk of compassion fatigue were more likely to report being burned out, using self‐criticism and giving up to manage stress, experiencing a greater variety of distressing clinical events, having larger patient caseloads, relying on religion as a coping strategy, having no children, and seeking support to manage stress. Respondents also provided critical incidents regarding their compassion fatigue and themes in these incidents are described. Practice and research recommendations are provided.
Enzyme‐Assisted Aqueous Extraction of Oil and Protein from Soybeans and Cream De‐emulsification
Authors: de Moura J. M. L. N. , Campbell K. , Mahfuz A. , Jung S. , Glatz C. E. , Johnson L.
Published: August 2008

The effects of two commercial endoproteases (Protex 6L and Protex 7L, Genencor Division of Danisco, Rochester, NY, USA) on the oil and protein extraction yields from extruded soybean flakes during enzyme‐assisted aqueous extraction processing (EAEP) were evaluated. Oil and protein were distributed in three fractions generated by the EAEP: cream + free oil, skim and insolubles. Protex 6L was more effective for extracting free oil, protein and total solids than Protex 7L. Oil and protein extraction yields of 96 and 85%, respectively, were obtained using 0.5% Protex 6L. Enzymatic and pH treatments were evaluated to de‐emulsify the oil‐rich cream. Cream de‐emulsification generated three fractions: free oil, an intermediate residual cream layer and an oil‐lean second skim. Total cream de‐emulsification was obtained when using 2.5% Protex 6L and pH 4.5. The extrusion treatment was particularly important for reducing trypsin inhibitor activity (TIA) in the protein‐rich skim fraction. TIA reductions of 69 and 45% were obtained for EAEP skim (the predominant protein fraction) from extruded flakes and ground flakes, respectively. Protex 6L gave higher degrees of protein hydrolysis (most of the polypeptides being between 1,000 and 10,000 Da) than Protex 7L. Raffinose was not detected in the skim, while stachyose was eliminated by α‐galactosidase treatment.
Enzymatic Synthesis of Biodiesel from Transesterification Reactions of Vegetable Oils and Short Chain Alcohols
Authors: Rodrigues Rafael Costa , Volpato Giandra , Wada Keiko , Ayub Marco Antônio Záchia
Published: August 2008

Biodiesel synthesis by alcoholysis of three vegetable oils (soybean, sunflower and rice bran) catalyzed by three commercial lipases (Novozym 435, Lipozyme TL‐IM and Lipozyme RM‐IM), and the optimization of the enzymes stability over repeated batches is described. The effects of the molar ratio of alcohol to oil and the reaction temperature with methanol, ethanol, propanol and butanol were also studied. All three enzymes displayed similar reaction kinetics with all three oils and no significant differences were observed. However, each lipase displayed the highest alcoholysis activity with a different alcohol. Novozym 435 presented higher activity in methanolysis, at a 5:1 methanol:oil molar ratio; Lipozyme TL‐IM presented higher activity in ethanolysis, at a 7:1 ethanol:oil molar ratio; and Lipozyme RM‐IM presented higher activity in butanolysis, at a 9:1 butanol:oil molar ratio. The optimal temperature was in the range of 30–35 °C for all lipases. The assessment of enzyme stability over repeated batches was carried out by washing the immobilized enzymes with different solvents (n‐hexane, water, ethanol, or propanol) after each batch. When washing with n‐hexane, approximately 90% of the enzyme activity remained after seven synthesis cycles.
The effects of maternal parenting style and religious commitment on self‐regulation, academic achievement, and risk behavior among African‐American parochial college students☆
Authors: Abar Beau , Carter Kermit L. , Winsler Adam
Published: August 2008

This study explored relations between religiosity, both parent and student, and maternal parenting style and student academic self‐regulation, academic achievement, and risk behavior among African‐American youth attending a parochial college. Eighty‐five students completed self‐report survey measures of religiosity, self‐regulation, academic achievement, and risk behavior. Participants also completed youth report measures of parental religiosity and perceived maternal parenting style. Correlational analyses show authoritative parenting to be associated with high levels of academic performance and study skills. Additional correlations revealed that highly religious students tend to perform well academically, study better, and engage in fewer risk behaviors than youth less committed to religion. Although no direct relations were observed between parenting style and student religiosity, maternal parenting style was found to moderate relations between parental and student religiosity. Findings are discussed in terms of their relevance to the population studied.
The speed of Muller's ratchet with background selection, and the degeneration of Y chromosomes
Authors: GORDO ISABEL , CHARLESWORTH BRIAN
Published: August 2008

The rate of accumulation of deleterious mutations by Muller's ratchet is investigated in large asexual haploid populations, for a range of parameters with potential biological relevance. The rate of this process is studied by considering a very simple model in which mutations can have two types of effect: either strongly deleterious or mildly deleterious. It is shown that the rate of accumulation of mildly deleterious mutations can be greatly increased by the presence of strongly deleterious mutations, and that this can be predicted from the associated reduction in effective population size (the background selection effect). We also examine the rate of the ratchet when there are two classes of mutation of similar but unequal effects on fitness. The accuracy of analytical approximations for the rate of this process is analysed. Its possible role in causing the degeneration of Y and neo-Y chromosomes is discussed in the light of our present knowledge of deleterious mutation rates and selection coefficients.
Physical activity, sedentary behaviour and energy balance in the preschool child: opportunities for early obesity prevention
Authors: Reilly John J.
Published: August 2008

Prevalence of obesity in preschool children has increased dramatically in recent years. The preschool years (age 3–6 years) have been regarded as critical for the programming of energy balance, via the concept of early ‘adiposity rebound’. Children who undergo early adiposity rebound are at increased risk of later obesity. Recent evidence suggests that associations between timing of adiposity rebound and later obesity may not reflect programming, but might denote that ‘obesogenic’ growth trajectories are often established by the preschool period. Studies of objectively-measured physical activity and sedentary behaviour in preschool children show that levels of physical activity are typically low and sedentary behaviour high. The review of evidence presented here is supportive of the hypothesis that physical activity is protective against obesity in the preschool period, and that sedentary behaviour, particularly television viewing, is obesogenic. Definitive evidence on dose–response relationships between physical activity, sedentary behaviour and obesity remain unclear. Dose–response evidence could be obtained fairly readily by intervention and longitudinal observational studies that use accelerometry in preschool children. The generalisability of much of the evidence base is limited and there is a need for research on the influence of physical activity and sedentary behaviour in the preschool years in the aetiology of obesity in the developing world.
Environmental determinants of healthy eating: in need of theory and evidence
Authors: Brug Johannes , Kremers Stef P. , Lenthe Frank van , Ball Kylie , Crawford David
Published: August 2008

In order to promote healthful nutrition, insight is needed into the determinants of nutrition behaviours. Behavioural determinant research and behavioural nutrition interventions have focused mostly on individual-level motivational factors. It has been argued that the individual's socio-cultural and physical environments may be the main determinants of nutrition behaviours. However, the theoretical basis and empirical evidence for environmental determinants of nutrition behaviours are not strong. The present paper is a narrative review informed by a series of systematic reviews and recent original studies on associations between environmental factors and nutrition behaviours to provide an overview and discussion of the evidence for environmental correlates and predictors of nutrition behaviour. Although the number of studies on potential environmental determinants of nutrition behaviours has increased steeply over the last decades, they include only a few well-designed studies with validated measures and guided by sound theoretical frameworks. The preliminary evidence from the available systematic reviews indicates that socio-cultural environmental factors defining what is socially acceptable, desirable and appropriate to eat may be more important for healthful eating than physical environments that define the availability and accessibility of foods. It is concluded that there is a lack of well-designed studies on environmental determinants of healthful eating behaviours. Preliminary evidence indicates that social environmental factors may be more important than physical environmental factors for healthful eating. Better-designed studies are needed to further build evidence-based theory on environmental determinants to guide the development of interventions to promote healthful eating.
On Some Inscribed Babylonian Alabastra
Authors: Finkel I. L. , Reade J. E.
Published: August 2008

Demand for scents, spices and comparable products from India and further east was a major incentive for the naval expeditions which led, after 1497 AD, to the creation of European empires in the Orient. There was the same demand in the ancient Mediterranean and Middle East, to which these goods travelled through the Red Sea or the Persian Gulf. People in Egypt and Babylonia in the classical period were both middlemen and consumers, and this paper draws attention to the existence of a few alabaster jars that reflect the trade. They are mainly in the Department of the Ancient Near East at the British Museum (previously called the Department of Western Asiatic Antiquities), and are inscribed in Babylonian or Greek with the names of scents or spices. While these inscriptions are unusual, perhaps many more jars were once inscribed in ink which is no longer visible.
Barotropic tides of the Chilean Inland Sea and their sensitivity to basin geometry
Authors: Aiken C. M.
Published: August 2008

The eight major tidal constituents of the Chilean Inland Sea (CIS, 41°–47°S) are simulated using the Regional Ocean Modeling System. In general, the simulated amplitude and phase of each constituent agree with those observed at various locations within the CIS to within 7 cm and 14°, respectively. In particular, the model simulates the major tidal constituent (M2) to within 1% in Puerto Montt, the location of maximum tidal amplitude, and within 5% elsewhere. Distinctions are seen between the character of the tide in the northern and southern sections of the CIS. The character of tidal propagation in the northern CIS is seen to share many of the properties of a forced damped channel with a resonant frequency of approximately 10 h−1, i.e., slightly higher than that of the shortest period semidiurnal tide. In contrast, the southern CIS does not respond as a forced channel due to the possibility for tidal propagation through the Chonos Archipelago, and as a result tidal amplitudes are smaller, and phase more homogeneous, than in the northern CIS. A series of additional simulations, together with the analytical solution for a harmonically forced branched channel, reveal that the modeled tides are highly sensitive to the resolution of the CIS's complex coastal geometry. In particular, it is found that under‐representation of the channels leading to the open ocean can cause CIS‐wide changes in M2 tidal amplitude and phase, highlighting the importance of these channels to the character of the tide in the CIS.
Large variations in balloon ascent rate over Hawaii
Authors: McHugh J. P. , Dors I. , Jumper G. Y. , Roadcap J. R. , Murphy E. A. , Hahn D. C.
Published: August 2008

A sequence of nine weather balloons were launched recently over the island of Hawaii during the nights of 12, 13, and 17 December, 2002, providing measurements of ascent rate, horizontal wind speed and direction, temperature, and other quantities. The measurements show short intervals of altitude with a large increase in ascent rate, occurring only near the tropopause, indicating regions of strong upward air velocity at this location. The large ascent rates correlate well to the strength of a jet stream, and with the presence of a local critical level, indicating mountain waves as the primary cause. No corresponding decreases in ascent rate were measured, suggesting strong three‐dimensional effects.
High‐frequency magnetospheric sounding at EISCAT: Some trials and their implications
Authors: Senior A. , Honary F. , Chapman P. J. , Rietveld M. T. , Kelso T. S. , Kosch M. J.
Published: August 2008

The results of some recent experiments employing the EISCAT HF “heating” facility at Ramfjordmoen, near Tromsø, Norway as a HF radar transmitter are described. The motivation for the experiments was the detection of “conjugate echoes” caused by geomagnetic field‐aligned ducting of the HF wave in the magnetosphere and reflection from the magnetically conjugate ionosphere. No such echoes were detected during the experiments, which is probably to be expected from consideration of the plasma density gradients required to sustain guidance of the waves at the low HF frequencies involved. However, echoes were obtained at ranges which could be consistent with backscattering from ionospheric irregularities in the equatorial and southern auroral regions; this is similar to spread‐Doppler clutter observed by large over‐the‐horizon radar (OTHR) systems. The experimental technique is described and the results discussed with a view toward future attempts to sound the lower magnetosphere using high‐power HF transmitters.
Ecohydrological responses on water diversion in the lower reaches of the Tarim River, China
Authors: Tao Hui , Gemmer Marco , Song Yudong , Jiang Tong
Published: August 2008

During the past 30 years, water ceased to flow in the lower reaches of the Tarim River in northwest China. A project was initiated that aims for ecosystem recovery and rehabilitation by means of transporting water through an open canal to the lower reaches of the Tarim River. In this study, the ecohydrological responses of this rare type project are assessed. Water loss‐runoff relationships and an index model for water loss rates and runoff are analyzed. The detected ecohydrological responses of the canal project include that water diversion dominates the dynamics of (1) the groundwater depth and (2) the tempo‐spatial variation of riparian vegetation close to the water channel. The relationships between groundwater depth, vegetation coverage, species richness and soil water content are clearly the main factors contributing to the riparian vegetation. Variations of water mineralization are significant, both temporally and spatially, at each sampling station within the lower reaches of the Tarim River. The study provides basic information on water diversion and stream corridor restoration in the lower reaches of the Tarim River. The results show associated mechanisms between riparian vegetation and hydrological variation in arid zone. This lays the theoretical and practical foundation for improving the evaluation system for supplementary water delivery and comprehensive improvement in the Tarim Basin. It also provides information on strengths and weakness in current practices. These are needed for the planning of ecological recovery and rehabilitation of damaged ecosystems in this and other arid areas in western and northern China.
Conditional integration of Incoherent Scattering in relation to flickering aurora
Authors: Grydeland T. , Gustavsson B. , Baddeley L. , Lunde J. , Blixt E. M.
Published: August 2008

In this report we present incoherent scatter radar (ISR) observations of ionospheric response to precipitation causing flickering aurora. Flickering aurora is caused by electron precipitation with modulations at frequencies higher than 5 Hz. To resolve the variation at these short time‐scales with ISR we have integrated together pulses at the same phase of the optical intensity variation observed with high‐speed narrow field‐of‐view imaging in white light to determine the intensity variation in the field aligned direction, which is also the direction of the beam of the EISCAT Svalbard Radar (ESR). Further we show that the 3% modulation in ISR back‐scattered power can be explained with electron heating by temporally modulated electron precipitation and electron cooling in collisions with ions and neutrals.
2D calculation of anharmonic OH vibrations in a layered hydroxide crystal
Authors: Gajewski Grzegorz , Mitev Pavlin D. , Hermansson Kersti
Published: August 2008

Anharmonic vibrational frequencies for the Raman-active (A1g) and the IR-active (A2u) modes have been calculated for the LiOH crystal within a plane-wave density functional theory (DFT) framework. We find that a two-dimensional quantum-mechanical vibrational approach, allowing for anharmonic coupling between symmetric and antisymmetric OH stretching modes, produces OH frequencies—both absolute frequencies and gas-to-solid frequency shifts—in good agreement with experiment. Remaining errors in the absolute frequencies are largely a consequence of the DFT model chosen. A one-dimensional normal-mode following vibrational treatment, on the other hand, fails to reproduce both absolute anharmonic frequencies and gas-to-solid frequency shifts.
Comment on “Dynamics of electro-optical switching processes in surface stabilized biaxial nematic phase found in bent-core liquid crystal” [J. Appl. Phys. 101, 034105 (2007)]
Authors: Stannarius Ralf
Published: August 2008

Lee et al. [J. Appl. Phys 101, 034105 (2007)] studied the Fréedericksz transition of a nematic bent-core mesogen in a planar cell. They claim that they have distinguished two different nematic phases in optical experiments, a uniaxial phase at a high temperature and a biaxial phase at a lower temperature. The commented paper contains several problematic passages and the substantial parts of the conclusions are invalid. Some experimental data appear to be inconsistent or incorrectly interpreted. We review the data and their interpretation, and analyze which conclusions are actually justified.
Driven chirped vorticity holes
Authors: Borich M. A. , Friedland L.
Published: August 2008

The formation and control of m-fold symmetric vorticity hole structures in a two-dimensional vortex patch with a line vortex core is studied within an adiabatic contour dynamics theory. The holes are formed by subjecting an initially circular vortex patch to an m-fold symmetric, oscillating, chirped frequency straining flow. The theory uses adiabatic invariants associated with the boundaries of the patch and describes all stages of evolution in the driven system, i.e., the emergence of the m-fold symmetric V-state, resonant passage through the boundary of the V-state, formation of vorticity holes, and autoresonant dynamics of the driven holes inside the vortex structure. The results of the theory are in a good agreement with the fast multipole-type simulations. In contrast to free (unstrained) m-fold symmetric vorticity hole structures, where only m=1 case is stable, resonantly driven phase-locked m>1 vorticity holes can be stabilized by the external strain. More complex, stable m-fold symmetric vorticity structures with local minima in vorticity distributions can be formed from initially axisymmetric distributions by external, chirped frequency strains.
Negative ions of nitroethane and its clusters
Authors: Stokes S. T. , Bowen K. H. , Sommerfeld T. , Ard S. , Mirsaleh-Kohan N. , Steill J. D. , Compton R. N.
Published: August 2008

Valence and dipole-bound negative ions of the nitroethane (NE) molecule and its clusters are studied using photoelectron spectroscopy (PES), Rydberg electron transfer (RET) techniques, and ab initio methods. Valence adiabatic electron affinities (EAas) of NE, C2H5NO2, and its clusters, (C2H5NO2)n, n=2–5, are estimated using vibrationally unresolved PES to be 0.3±0.2eV (n=1), 0.9±0.2eV (n=2), 1.5±0.2eV (n=3), 1.9±0.2eV (n=4), and 2.1±0.2eV (n=5). These energies were then used to determine stepwise anion-neutral solvation energies and compared with previous literature values. Vertical detachment energies for (C2H5NO2)n− were also measured to be 0.92±0.10eV (n=1), 1.63±0.10eV (n=2), 2.04±0.10eV (n=3), and 2.3±0.1eV (n=4). RET experiments show that Rydberg electrons can be attached to NE both as dipole-bound and valence bound anion states. The results are similar to those found for nitromethane (NM), where it was argued that the diffuse dipole state act as a “doorway state” to the more tightly bound valence anion. Using previous models for relating the maximum in the RET dependence of the Rydberg effective principle number nmax*, the dipole-bound electron affinity is predicted to be ∼25meV. However, a close examination of the RET cross section data for NE and a re-examination of such data for NM finds a much broader dependence on n* than is seen for RET in conventional dipole bound states and, more importantly, a pronounced ℓ dependence is found in nmax* (nmax* increases with ℓ). Ab initio calculations agree well with the experimental results apart from the vertical electron affinity value associated with the dipole bound state which is predicted to be 8meV. Moreover, the calculations help to visualize the dramatic difference in the distributions of the excess electron for dipole-bound and valence states, and suggest that NE clusters form only anions where the excess electron localizes on a single monomer.
Chemical short-range order in liquid Al–Ni alloys
Authors: Egry Ivan , Hennet Louis , Kehr Mirko , Mathiak Gerhard , De Panfilis Simone , Pozdnyakova Irina , Zanghi Didier
Published: August 2008

The chemical short-range structure was studied in liquid Al–Ni alloys by x-ray absorption spectroscopy as a function of temperature and composition. A containerless technique, combining aerodynamic levitation and inductive heating, was used to position and melt the samples. The fluorescence yield x-ray absorption at the Ni K edge was measured by a multichannel solid-state Ge detector. The number of heteroatomic pairs around the scatterer is higher than for a homogeneous alloy.
Orientational correlations in molecular liquid SnI4
Authors: Pusztai László , Pothoczki Szilvia , Kohara Shinji
Published: August 2008

The total scattering structure factor of liquid tin tetraiodide (SnI4) has been interpreted by means of reverse Monte Carlo (RMC) modeling. From the sets of particle coordinates provided by RMC, which are consistent with experimental results within errors, partial radial distribution functions as well as correlation functions characterizing mutual orientations of molecules as a function of distance between molecular centers can be calculated. Interestingly and very much in contrast to liquids of symmetric XCl4 molecules, the corner-to-face (or “Apollo”)-type orientation of neighboring molecules has a significant (about 20%) occurrence in liquid SnI4. Via comparison with a reference system, obtained by hard sphere Monte Carlo simulation, we demonstrate that intermolecular two-body correlations in liquid SnI4 are determined largely by excluded volume (steric) effects; that is, intermolecular two-body interactions play only a minor role. On the other hand, as it is manifested in the large difference between the reference and “real” systems in terms of the orientational correlations, higher order interactions are indispensable. This feature can explain the extremely rich phase behavior of SnI4 at high pressures.
Photoluminescence study of terbium-exchanged ultrastable Y zeolites: Number of species, photoluminescence decays, and decay-associated spectra
Authors: Tiseanu Carmen , Lórenz-Fonfría V. A. , Parvulescu V. I. , Gessner A. , Kumke M. U.
Published: August 2008

Terbium-exchanged ultrastable Y (USY) zeolites were investigated by using time-resolved photoluminescence spectroscopy techniques and methods. To determine the distribution of terbium species in USY zeolites together with their photoluminescence properties, several analysis methods for the time-resolved luminescence spectra were used such as the area normalization of time-resolved photoluminescence spectra, singular value decomposition, global nonlinear least squares, and the maximum entropy. Except for a questionable long lifetime, small contribution of a terbium species with lifetime of 1.9–2.1 ms, all the experimental and analysis results converged to a two terbium species distribution with lifetimes varying between 410–440 and 1000–1100 μs. The effects of the silylation of terbium-exchanged USY zeolites with phenyl-, vinyl-, and hexadecyltrimethoxysilanes on the lanthanide’s photoluminescence properties were also described.
Origin of negative and dispersive features in anti-Stokes and resonance femtosecond stimulated Raman spectroscopy
Authors: Frontiera Renee R. , Shim Sangdeok , Mathies Richard A.
Published: August 2008

Femtosecond stimulated Raman spectroscopy is extended to probe ground state anti-Stokes vibrational features. Off resonance, negative anti-Stokes features are seen that are the mirror image of the positive Stokes side spectra. On resonance, the observed dispersive lineshapes are dramatically dependent on the frequencies of the picosecond pump and femtosecond probe pulses used to generate the stimulated Raman spectra. These observations are explained by the contributions of the inverse Raman and hot luminescence four-wave mixing processes discussed by Sun et al. [J. Chem. Phys. 128, 144114 (2008)], which contribute to the overall femtosecond stimulated Raman signal.
Exciton-phonon interactions observed in blue emission band in Te-delta-doped ZnSe
Authors: Jo M. , Hayashi Y. , Kumano H. , Suemune I.
Published: August 2008

Photoluminescence (PL) in the blue wavelength region originating from a no-phonon (NP) transition at 2.734 eV and longitudinal optical (LO) phonon sidebands of Te isoelectronic centers (ICs) were clearly resolved after thermal annealing by δ-doping of Te in ZnSe layers. Broad luminescence (conventionally called the S1 band) had been previously observed in this region (i.e., around 2.65 eV). The PL intensities of the NP line and the phonon replicas followed a Poisson distribution with a mean phonon number (Huang–Rhys factor) of S∼1.1. This indicates that the broadening of the 2.65 eV emission band is due to the superposition of the NP lines and their LO phonon replicas originating from the Te ICs with slight variations in their transition energies. The origin of the luminescence is discussed in relation to linearly polarized PL measurements.
Double gate GaInZnO thin film transistors
Authors: Lim Hyuck , Yin Huaxiang , Park Jin-Seong , Song Ihun , Kim Changjung , Park JaeChul , Kim SunIl , Kim Sang-Wook , Lee Chang Bum , Kim Yong C. , Park Young Soo , Kang Donghun
Published: August 2008

We fabricated gallium-indium-zinc oxide (GIZO) thin film transistors (TFTs) having a double-gated (DG) structure and studied the back gate effect on device performance. DG GIZO TFTs showed better threshold voltage (Vth), swing factor (S), and on/off current than those with a single gate. With the variation in back gate bias, the device performance significantly changes due to the modification of field distribution near the GIZO channel. It is believed that our DG structure is an effective way to improve the performance of GIZO oxide transistors and suppress the formation of an accumulation layer at the back surface.
Dam-break flows with resistance as agents of sediment transport
Authors: Emmett M. , Moodie T. B.
Published: August 2008

When a semi-infinite body of fluid initially at rest behind a vertical retaining wall is suddenly released by the removal of the barrier, the resulting flow over either a horizontal or a sloping bed is referred to as a dam-break flow. When resistance to the flow is neglected, the exact solution in the case of a horizontal bed with or without “tail water” may be obtained on the basis of shallow-water theory via the method of characteristics, and the results are well known. The inclusion of the effects of resistance in the form of basal friction that are needed in order to bring the mathematical solutions into closer harmony with the experimental results modifies the wave speed and flow profile near the head of the wave significantly and the simple exact solution of the shallow-water equations can no longer be employed as a reasonable description of the flow field. It is our intention here to study dam-break flows as agents of sediment transport taking into account basal friction and the attendant changes in depth profiles near the head, as well as the effects of particle concentrations on the flow dynamics including both erosion and deposition of particles arising through the interaction of the flow with the bed material. We shall consider shallow flows over dry beds and investigate the effects of changes in the depositional and erosional models employed as well as in the nature of the drag acting on the flow. These models offer some insight into the transport of sediment in the worst case scenario of complete and instantaneous collapse of a dam. They are also anticipated to provide information on other sheet flow events where particle transport plays a significant role in the flow dynamics.
Anomalous circular ac susceptibility and magnetoimpedance for nearly nonmagnetostrictive amorphous wire
Authors: Chen D.-X.
Published: August 2008

The frequency dependent low-field circular ac susceptibility χ=χ′−jχ″ of a nearly nonmagnetostrictive Co68.2Fe4.3Si12.5B15 amorphous wire annealed at 470 °C is determined by impedance Z measurements under stepwise decreased longitudinal dc field Hdc from 216 to −216 A/m after premagnetization at 16 kA/m. It is found that compared with the results of the classical eddy-current model, the measured low-frequency loss factor is larger by an anomaly factor η between 1.5 and 3, depending on the value of Hdc. However, the χ(f) curve at each value of Hdc may be well fitted by an eddy-current model of bamboo-domain wall displacements if the material conductivity is replaced by a greater effective one and a proper value of effective domain size is chosen. The physical mechanism of such a fitting is discussed based on previous studies on anomalous dc circular susceptibility. This anomalous χ(f,Hdc) leads to an anomalous magnetoimpedance Z(Hdc) with a two-peak feature when frequency is high.
Phase behaviors of polymer solutions using molecular simulation technique
Authors: Yang Jung Ho , Bae Young Chan
Published: August 2008

Phase behaviors of polymer solutions are estimated using a combination of thermodynamic models and molecular simulation technique. In general, many parameters of binary systems are determined by fitting a thermodynamic model with experimental data. In this study, we obtained all parameters using molecular simulation. To take the specific interaction into account, we assume that it only occurs between a solvent molecule and a specific group. Our results show that the theoretical treatment accounting for the specific interaction gives more accurate predictions than those without consideration of specific interaction. Also, our approach describes the phase equilibria of various polymer solutions over the entire concentration remarkably well.
Research on the magneto-optic current sensor for high-current pulses
Authors: Deng Xiangyang , Li Zeren , Peng Qixian , Liu Jun , Tian Jianhua
Published: August 2008

A new magneto-optic current sensor with a dual-orthogonal configuration is proposed and demonstrated, which can resolve the problem which value of high-current pulses is ambiguous from the Faraday rotation in the conventional magneto-optic current sensor. In this dual-orthogonal configuration, the transmission axis of the polarizer makes two given angles, which are 0° and 45°, with the orientation of the s-polarized lights of two polarizing cube beam splitters. If the intrinsic linear birefringence of the sensing element is one-fourth less than the Faraday rotation generated from the high-current pulse, the measurement current influenced by it can be ignored and four outputs of the magneto-optic current sensor are in quadrature. The value of the current pulse can be calculated by an arctangent data reduction method, which can avoid the insensitive zone of the sine function, where the measurement current has a reduced accuracy. A measurement of the high-current pulse (up to 720kA) of an electric gun, with good theoretical accuracy (∼3%) and in agreement well with that of the calibrated Rogowski coil, is launched.
The structural and electronic properties of InnN(n=1–13) clusters
Authors: Zhang Wen-Qing , Sun Jian-Min , Zhao Gao-Feng , Zhi Li-Li
Published: August 2008

The structural and electronic properties of InnN(n=1–13) clusters have been investigated by density-functional theory with the generalized gradient approximation. The results indicate that the equilibrium structures of InnN are linear for n=1,2, planar for n=3–5, and three dimensional for n=6–13. Maximum peaks were observed for InnN clusters at n=3,7,9 on the size dependence for second-order energy difference. These imply that these clusters possess relatively higher stability, which is consistent with the case of binding energy per atom. Moreover, the results show that the bonding in small InnN clusters has a little ionic character by Mulliken population analysis. The energy gap between the highest occupied and lowest unoccupied molecular orbitals, the vertical ionization potential and electron vertical affinity (VIP and VEA) form an even-odd alternating pattern with increasing cluster size. In general, the VIP tends to lower as the cluster size increases, while the VEA tends to increase as the cluster size increases.
Extracting the polarizability anisotropy from the transient alignment of HBr
Authors: Pinkham D. , Vogt T. , Jones R. R.
Published: August 2008

We use 40 fs, 780 nm laser pulses to transiently align HBr molecules. We study the temporal dynamics of the resultant rotational wavepacket to gain insight into the electronic properties of the molecule. We show that the HBr polarization anisotropy can be extracted by comparing the time dependence of the HBr alignment with both the analogous alignment behavior of N2 and the predictions of a rigid-rotor model.
Advances in the development of wire mesh reactor for coal gasification studies
Authors: Zeng Cai , Chen Lei , Liu Gang , Li Wenhua , Huang Baoming , Zhu Hongdong , Zhang Bing , Zamansky Vladimir
Published: August 2008

In an effort to further understand the coal gasification behavior in entrained-flow gasifiers, a high pressure and high temperature wire mesh reactor with new features was recently built. An advanced LABVIEW-based temperature measurement and control system were adapted. Molybdenum wire mesh with aperture smaller than 70μm and type D thermocouple were used to enable high carbon conversion (>90%) at temperatures >1000°C. Gaseous species from wire mesh reactor were quantified using a high sensitivity gas chromatography. The material balance of coal pyrolysis in wire mesh reactor was demonstrated for the first time by improving the volatile’s quantification techniques.
Near-dissipation range in nonlocal turbulence
Authors: Bershadskii A.
Published: August 2008

Viscous perturbations to scaling are studied in the near-dissipation range of isotropic turbulence. A quantitative relationship between effective strain of the nonlocal interactions and viscosity has been found. It is shown that nonlocal interactions determine the energy spectrum in isotropic turbulence at small Reynolds numbers. It is also shown that for moderate Reynolds numbers the bottleneck effect is determined by the same nonlocal interactions. The role of the large- and small-scale covariances at the nonlocal interactions and in energy balance has been investigated. A possible hydrodynamic mechanism of the nonlocal solution instability at large scales has been briefly discussed. Analogous approach has also been developed for passive scalar and for the energy dissipation rate spectrum. All results are supported by a comparison with the data of the laboratory experiments and numerical simulations.
Resonant tunneling through double-bended graphene nanoribbons
Authors: Zhang Z. Z. , Chang Kai , Chan K. S.
Published: August 2008

We investigate theoretically resonant tunneling through double-bended graphene nanoribbon (GNR) structures, i.e., armchair-edged GNRs (AGNRs) in between two semi-infinite zigzag GNR leads. Our numerical results demonstrate that the resonant tunneling can be tuned dramatically by the Fermi energy and the length and/or widths of the AGNR for both the metallic and semiconductorlike AGNRs. The structure can also be use to control the valley polarization of the tunneling currents and could be useful for potential application in valleytronics devices.
Temporal dynamics of fish assemblages in small seasonal streams in the Queensland tropics
Authors: Perna Colton , Pearson Richard G.
Published: August 2008

The structure and dynamics of fish assemblages were studied in two small coastal streams in the seasonal tropics of northern Queensland. The study encompassed two consecutive wet seasons of contrasting flood magnitudes. Flooding had substantial effects on physical habitats by shifting sediments and removing aquatic macrophytes, and short-term changes in the fish assemblages reflected these habitat changes. Changes were of higher magnitude following a one-in-eighteen-year flood than a one-in-one-year flood; however, in both cases return to prior assemblage structure occurred as the dry season progressed, but with more rapid recovery after the smaller event. The stream fish assemblages showed high resilience to the flood disturbance at magnitudes seen in this study.
An insight into what superconducts in polycrystalline boron-doped diamonds based on investigations of microstructure
Authors: Dubrovinskaia N. , Wirth R. , Wosnitza J. , Papageorgiou T. , Braun H. F. , Miyajima N. , Dubrovinsky L.
Published: August 2008

The discovery of superconductivity in polycrystalline boron-doped diamond (BDD) synthesized under high pressure and high temperatures [Ekimov,
et al.
(2004)
Nature
428:542–545] has raised a number of questions on the origin of the superconducting state. It was suggested that the heavy boron doping of diamond eventually leads to superconductivity. To justify such statements more detailed information on the microstructure of the composite materials and on the exact boron content in the diamond grains is needed. For that we used high-resolution transmission electron microscopy and electron energy loss spectroscopy. For the studied superconducting BDD samples synthesized at high pressures and high temperatures the diamond grain sizes are ≈1–2 μm with a boron content between 0.2 (
2
) and 0.5 (
1
) at %. The grains are separated by 10- to 20-nm-thick layers and triangular-shaped pockets of predominantly (at least 95 at %) amorphous boron. These results render superconductivity caused by the heavy boron doping in diamond highly unlikely.
Acquired hematopoietic stem cell defects determine B-cell repertoire changes associated with aging
Authors: Guerrettaz Lisa M. , Johnson Sara A. , Cambier John C.
Published: August 2008

Aging is associated with an inability to mount protective antibody responses to vaccines and infectious agents. This decline is associated with acquisition of defects in multiple cellular compartments, including B cells. While peripheral B-cell numbers do not decline with aging, the composition of the compartment appears to change, with loss of naïve follicular B cells, accumulation of antigen-experienced cells, and alteration of the antibody repertoire. The underlying cause of this change is unknown. We tested the hypothesis that aging-associated repertoire changes can be attributed directly to decreased B lymphopoiesis. Using an Ig transgenic model to report changes in the B-cell repertoire, we show that the reduced B-cell generative capacity of “aged” long-term reconstituting hematopoietic stem cells (LT-HSCs) alters the representation of antigen specificities in the peripheral B-cell repertoire. Further, we show that reconstitution using suboptimal numbers of fully functional LT-HSCs results in the generation of a similarly altered B-cell repertoire. This may be an important factor to consider when deciding the number of bone marrow cells to transplant in the clinical setting. In conclusion, when B lymphopoiesis is limited peripheral B-cell homeostasis is altered. This is reflected in reduced diversity of the B-cell repertoire, which likely reduces the protective quality of the immune response.
The effect of gestures on second language memorisation by young children
Authors: Tellier Marion
Published: August 2008

This article examines the impact of gesture on second language memorisation in teaching to very young learners. Twenty French children (mean age 5;5) took part in an experiment. They had to learn eight words in a foreign language (English). One group of children (N = 10) were taught words with pictures and another group (N = 10) words with accompanying gestures. Children in this group had to reproduce the gestures while repeating the words. Results show that gestures and especially their reproduction significantly influence the memorisation of second language (L2) lexical items as far as the active knowledge of the vocabulary is concerned (being able to produce words and not only understand them). This finding is consistent with theories on multimodal storage in memory. When reproduced, gestures not only act as a visual modality but also as a motor modality and thus leave a richer trace in memory.
Definitional verbal patterns for semantic relation extraction
Authors: Sierra Gerardo , Alarcón Rodrigo , Aguilar César , Bach Carme
Published: August 2008

In this paper we present a description of the role of definitional verbal patterns for the extraction of semantic relations. Several studies show that semantic relations can be extracted from analytic definitions contained in machine-readable dictionaries (MRDs). In addition, definitions found in specialised texts are a good starting point to search for different types of definitions where other semantic relations occur. The extraction of definitional knowledge from specialised corpora represents another interesting approach for the extraction of semantic relations. Here, we present a descriptive analysis of definitional verbal patterns in Spanish and the first steps towards the development of a system for the automatic extraction of definitional knowledge.
Regulation of ovarian UT‐OC‐2 carcinoma cells by cytokines: Effects on cell proliferation, activation of transcription factors and apoptosis
Authors: SEPPÄNEN MARJO , LIN LIN , SAARINEN RIITTA , PUNNONEN REIJO , VIHKO KIMMO K.
Published: August 2008

Background. It is known that immunologic factors are involved in the regulation of the growth of ovarian carcinoma and that granulocytes are often found on the site of ovarian cancer. Therefore, we chose to investigate the effects of cytokines on UT‐OC‐2 ovarian endometrioid adenocarcinoma cells in vitro. In order to investigate the molecular mechanisms involved, the activation of two key DNA‐binding proteins, AP‐1 and transcription factor NF‐κB (NF‐κB), was studied. Since DNA extracted from the UT‐OC‐2 cells showed fragmentation typical of apoptosis, we also studied the effects of cytokines on this event. Methods. The effects of the studied cytokines on the proliferation of UT‐OC‐2 cells were investigated by 125I‐deoxyuridine incorporation. The activation of DNA‐binding proteins was studied by electrophoretic mobility shift assay. Statistical analyses were performed by Student's t‐test. Results. Interferon α (IFN‐α), transforming growth factor β1 (TGF‐β1), tumor necrosis factor α (TNF‐α) and interferon γ (IFN‐γ) all had a significant inhibitory effect on cell proliferation. Granulocyte colony stimulating factor (GM‐CSF) did not alter cell proliferation significantly. Transcription factors AP‐1 and NF‐κB were both found to be constitutively active in UT‐OC‐2 ovarian carcinoma cells. We were able to show that IFN‐γ, TGF‐β1 and TNF‐α all increased the binding activity of transcription factor AP‐1 (AP‐1). The binding activity of transcription factor NF‐κB was not altered by any of the cytokines studied, with the exception of IFN‐γ. IFN‐γ had also a clear inhibitory effect on the apparent magnitude of apoptosis, whereas TNF‐α and TGF‐β1 showed no effect. Conclusion. The results of this study show that TNF‐α, TGF‐β1, and IFN‐γ are able to inhibit the proliferation of UT‐OC‐2 ovarian carcinoma cells. Activation of AP‐1 seems to be involved in the growth‐regulating processes induced by IFN‐γ, TGF‐β1 and TNF‐α; IFN‐γ is also able to increase the binding activity of NF‐κB and inhibited apoptosis in ovarian cancer cells.
Identification and Characterization of a Novel Efficient Resistance Response to the Furoviruses SBWMV and SBCMV in Barley
Authors: Lyons Rebecca , Hammond-Kosack Kim E. , Kanyuka Kostya
Published: August 2008

The interaction between the furoviruses Soilborne cereal mosaic virus (SBCMV) and Soilborne wheat mosaic virus (SBWMV) and their main host wheat is well documented; however, to date, only a few reports have addressed the response of other cereal species to these viruses. Here, we show that, in contrast to wheat, barley germplasm is a rich source of resistance to furoviruses. Moreover, we demonstrate that barley genotypes respond differentially to SBCMV and SBWMV, thereby providing an additional biological basis for classification of these viruses as two separate species. Following natural (soil) inoculation, some barley genotypes permitted foliar infection by SBWMV, whereas all 22 genotypes tested were resistant to SBCMV. Resistance is unlikely to be directed toward the virus vector, because Polymyxa graminis DNA was detected in the roots of all tested genotypes. Resistance to SBCMV in some barley genotypes was overcome by artificial virus inoculation onto the leaves, suggesting a block on virus translocation from roots to shoots as in resistant wheat genotypes. However, other genotypes were fully resistant following both inoculation techniques. One barley genotype, ‘Dayton,’ exhibited extreme resistance to both furoviruses. Further molecular analyses suggested that this novel and highly efficient resistance to furoviruses in barley operates by limiting virus spread from the primary inoculated cells.