bluuebunny/crossref_metadata_2025 huggingface dataset:
Water in hydrated orthorhombic lysozyme crystal: Insight from atomistic simulations
Authors: Hu Zhongqiao , Jiang Jianwen , Sandler Stanley I.
Published: August 2008

Biologically important water in orthorhombic lysozyme crystal is investigated using atomistic simulations. A distinct hydration shell surrounding lysozyme molecules is found from the number distribution of water molecules. While the number of water molecules in the hydration shell increases, the percentage decreases as the hydration level rises. Adsorption of water in the lysozyme crystal shows type-IV behavior. At low hydration levels, water molecules primarily intercalate the minor pores and cavity in the crystal due to the strong affinity between protein and water. At high hydration levels, the major pores are filled with liquidlike water as capillary condensation occurs. A type-H4 hysteresis loop is observed in the adsorption and desorption isotherms. The locations of the water molecules identified from simulation match fairly well with the experimentally determined crystallographic hydration sites. As observed in experiment, water exhibits anomalous subdiffusion because of the geometric restrictions and interactions of protein. With increasing hydration level, this anomaly is reduced and the diffusion of water tends to progressively approach normal Brownian diffusion. The flexibility of protein framework slightly enhances water mobility, but this enhancement decreases with increasing hydration level.
Lu
2
O
3
∕
Al
2
O
3
gate dielectrics for germanium metal-oxide-semiconductor devices
Authors: Darmawan P. , Chan M. Y. , Zhang T. , Setiawan Y. , Seng H. L. , Chan T. K. , Osipowicz T. , Lee P. S.
Published: August 2008

Effect of Ge out diffusion into Lu2O3∕Al2O3 high-k dielectric stack was investigated. Increasing Ge signal intensity with increasing annealing temperature was observed, which suggests that there may be excessive Ge incorporation into the high-k film. The electrical measurement shows an improvement of the k value with annealing temperature, as well as an increasing trend in the leakage current density suggesting degradation in electrical performance due to Ge incorporation. Our work suggests that 8.8at.% of Ge in the film is excessive and result in degradation of the electrical performance of the device due to the increased leakage current.
Lamb waves in phononic crystal slabs with square or rectangular symmetries
Authors: Brunet Thomas , Vasseur Jérôme , Bonello Bernard , Djafari-Rouhani Bahram , Hladky-Hennion Anne-Christine
Published: August 2008

We report on both numerical and experimental results showing the occurrence of band gaps for Lamb waves propagating in phononic crystal plates. The structures are made of centered rectangular and square arrays of holes drilled in a silicon plate. A supercell plane wave expansion method is used to calculate the band structures and to predict the position and the magnitude of the gaps. The band structures of phononic crystal slabs are then measured using a laser ultrasonic technique. Lamb waves in the megahertz range and with wave vectors ranging over more than the first two reduced Brillouin zones are investigated.
Laser pulse induced gold nanoparticle gratings
Authors: Hung Wen-Chi , Cheng Wood-Hi , Tsai Ming-Shan , Chung Wei-Chih , Jiang I-Min , Yeh Pochi
Published: August 2008

We report the results of our experimental investigation of laser induced gold nanoparticle gratings and their optical diffraction properties. A single shot of a pair Nd-YAG laser pulses with the same polarization is directed toward a 6 nm thick gold film on a substrate of polymethyl methacrylate. As a result of the laser illumination, the thin gold film is fragmented into an array of nanoparticles. Through the observation of scanning electron and dark-field optical microscopes, we discovered that the morphology of the gold nanoparticle grating is dependent on the fluence of laser pulse. The spectrum of first order diffraction shows the dependence on the absorbance property due to the presence of the nanoparticles. The ablation of nanothickness thin films via the use of laser pulses may provide a simple and efficient method for the fabrication of nanoscale structures, including two dimensional arrays of nanoparticles.
Sharp thermal emission and absorption from conformally coated metallic photonic crystal with triangular lattice
Authors: Biswas R. , Zhou D. , Puscasu I. , Johnson E. , Taylor A. , Zhao W.
Published: August 2008

A metallic photonic crystal consisting of a triangular lattice of holes in a silicon layer coated with gold is fabricated at a lattice pitch of 3.75 μm using conventional lithographic methods. The photonic crystal exhibits a deep reflection minimum and sharp thermal emission peak near the lattice spacing. Scattering matrix simulations agree well with measurements. This simple structure with a single patterned metallic layer has no emission sidebands and can be scaled to other lattice spacings to tune the wavelength of the absorption and emission peak.
Energy alignment induced negative differential resistance: The role of hybrid states in aromatic molecular devices
Authors: Fan Wei , Zhang R. Q. , Rocha A. Reily , Sanvito Stefano
Published: August 2008

Hybridization in aromatic molecules plays an important role in determining their electron transport properties. When an sp2 bonded aromatic ring hybridizes with a carbon pair in either sp3, sp2, or sp form, only sp2 and sp result in a delocalized state across the whole molecule, opening a channel for transport. At the same time negative differential resistance (NDR) is found only in the sp2 and sp cases. An energy alignment scheme is adopted to elucidate the NDR process. This is constructed by comparing the positions of frontier molecular levels and the states of leads. It is revealed that the alignment between lead states located around the Fermi energy with the lowest unoccupied molecular orbital of the central molecule is the main cause of the NDR.
Gallium phosphide photonic crystal nanocavities in the visible
Authors: Rivoire Kelley , Faraon Andrei , Vuckovic Jelena
Published: August 2008

Photonic crystal nanocavities at visible wavelengths are fabricated in a high refractive index (n>3.2) gallium phosphide membrane. The cavities are probed via a cross-polarized reflectivity measurement and show resonances at wavelengths as low as 645 nm at room temperature, with quality factors between 500 and 1700 for modes with volumes 0.7(λ/n)3. These structures could be employed for submicron scale optoelectronic devices in the visible, and for coupling to emitters with resonances in the visible such as nitrogen vacancy centers, and biomolecules and organic molecules.
Polarization offsets of compositionally graded Nd-substituted Bi4Ti3O12 ferroelectric thin films
Authors: Wu Di , Wu Hao , Fu Zhen , Zhao Chao , Li Aidong
Published: August 2008

The vertical offsets of hysteresis loops of compositionally graded Nd-substituted Bi4Ti3O12 (BNdT) ferroelectric films were studied as functions of the Nd gradient, the temperature, and the amplitude of driving voltage. We show that graded BNdT films may exhibit no offsets at room temperature and both graded and nongraded BNdT films exhibit pronounced offsets at elevated temperatures. The offset does not have a direct relation with the composition gradient but increases as the maximum voltage is increased. It is verified that the offset increases with the increase in asymmetry of leakage currents at positive and negative biases.
Morphological and chemical optimization of ex situ NH4F (40%) conditioned Si(111)-(1×1):H
Authors: Lublow M. , Stempel T. , Skorupska K. , Muñoz A. G. , Kanis M. , Lewerenz H. J.
Published: August 2008

Synchrotron radiation photoelectron spectroscopy was employed to investigate the chemical state of Si(111) surfaces upon anisotropic etching in concentrated NH4F solution. Minute amounts of oxidized silicon were detected and attributed to the fast Si–H–OH formation at atomic steps. Combining in situ optical and scanning probe techniques, consecutive chemical treatments were developed to achieve optimized morphological and chemical surface properties. Native oxides and a stressed SiO2/Si layer are removed by a two-step NH4F treatment leading to a terraced surface without triangular etch pits; subsequently, silicon in the Si1+/2+/3+ valence states is dissolved by HF (50%) while the surface topography is preserved.
Parallel electric fields in nonlinear magnetosonic waves in an electron-positron-ion plasma
Authors: Takahashi Seiichi , Sato Masatoshi , Ohsawa Yukiharu
Published: August 2008

The electric field E∥ along the magnetic field B in nonlinear magnetosonic waves in a three-component plasma is studied with theory based on a three-fluid model and with fully kinetic, electromagnetic, particle simulations. The theory for small-amplitude (ϵ⪡1) pulses shows that the integral of E∥ along B, F=−∫E∥ds, is proportional to ϵ(pe0−pp0) in warm plasmas, where pe0 and pp0 are, respectively, the electron and positron pressures, and proportional to ϵ2mivA2∕(1+vA2∕c2)3 in cold plasmas, where vA is the Alfvén speed. These predictions are verified with simulations. Furthermore, for shock waves with ϵ∼O(1), simulation values are consistent with the phenomenological relation ne0eF∼ϵ(ρvA2+Γepe0)(ni0∕ne0), where ρ is the mass density and Γe is the specific heat ratio. These results indicate that E∥ can be strong in strong magnetic fields.
The torsional vibration of the CO2–N2O complex determined from its infrared spectrum
Authors: Afshari Mahin , Dehghany M. , Moazzen-Ahmadi N. , McKellar A. R. W.
Published: August 2008

The spectra of the weakly bound complex CO2–N2O are studied in the regions of the ν1 and ν3 fundamentals of N2O and the ν3 fundamental of CO2 using a rapid-scan tunable diode laser spectrometer to probe a pulsed supersonic jet expansion. Five bands are measured and analyzed, of which four have not been previously studied. Two bands at 2225.75 and 1279.58 cm−1, with a/b-type rotational structure, are assigned to the ν1 and ν3 fundamentals of the N2O component of the complex. Small perturbations are noted in the ν3 band, similar to those observed previously for the nonpolar dimer (N2O)2 in the ν3 and ν1+ν3 regions. The previously known band at 2348.86 cm−1 in the region of the ν3 CO2 stretch is analyzed in improved detail. Weaker c-type bands at 2251.46 and 2374.67 cm−1 are assigned as combinations of the intermolecular torsional (out-of-plane) vibration plus the N2O ν1 and CO2 ν3 stretches, respectively. The resulting torsional frequency of CO2–N2O is experimentally determined for the first time to be 25.8 cm−1.
A method to measure the electron temperature and density of a laser-produced plasma by Raman scattering
Authors: Jang H. , Hur M. S. , Lee J. M. , Cho M. H. , Namkung W. , Suk H.
Published: August 2008

A method is proposed to investigate the electron temperature and density of a laser-produced plasma simultaneously, using the temperature dependence difference of the Raman forward scattering (RFS) and backward scattering (RBS). Density and temperature dependence of spectra from the RBS and the RFS in a laser produced plasma were investigated by one-dimensional particle-in-cell simulations in the nonrelativistic regime. This technique has a great advantage as a simple diagnostic of plasma characteristics in the sense that it can be performed only with the pump laser, without any additional probe laser.
Electrical charging of a single quantum dot by a spin polarized electron
Authors: Ghali M. , Kümmell T. , Wenisch J. , Brunner K. , Bacher G.
Published: August 2008

Voltage controlled electrical charging of a single InAs quantum dot by a spin polarized electron from a ZnMnSe spin aligner is presented, and the spin information is read out optically. We demonstrate that the characteristic single quantum dot photoluminescence polarization pattern of the negative trion and the neutral exciton lines directly reflects the spin state of the electrically injected electron.
Ferromagnetism and ferroelectricity in highly resistive Pb0.7Sr0.3(Fe0.012Ti0.988)O3 nanoparticles and its conduction by variable-range-hopping mechanism
Authors: Verma Kuldeep Chand , Singh M. , Kotnala R. K. , Negi N. S.
Published: August 2008

The enhancement in ferromagnetism and ferroelectricity at room temperature for Pb0.7Sr0.3(Fe0.012Ti0.988)O3 (PSFT) nanoparticles is proved by magnetization and polarization hysteresis loop. The x-ray diffraction and micrograph show that the PSFT nanoparticles have distorted tetragonal single phase, and their average particle’s size is 8 nm. The effect of Sr content reduces the particle size, and hence the multiferroic system becomes more resistive, which dominates the superparamagnetic/paraelectric relaxation. The variable-range-hopping conduction mechanism explained the high resistivity of PSFT nanoparticles, which suggests that the room temperature movement of electrons involves short-range order through defect states.
Implications of habitat-specific growth and physiological condition on juvenile crab population structure
Authors: Amaral Valter , Cabral Henrique N. , Paula José
Published: August 2008

Post-settlement processes can regulate the size and structure of marine invertebrate and fish populations. Faster growth and better physiological condition generally increase the survival potential of early juveniles, being usually associated with structurally complex habitats. Successive cohorts of early juvenile Carcinus maenas were followed in sandy and seagrass (Zostera noltii) habitats in the Mira Estuary, Portugal, to estimate growth and physiological condition (evaluated by RNA/DNA ratio) of juvenile populations. Mean cohort growth was similar in both habitats. However, in the sandy habitat, population size structure progressed to cohorts of larger carapace width (CW) and the RNA/DNA ratio was always higher than in the Z. noltii habitat. In this habitat, cohorts of low CW prevailed throughout and RNA/DNA ratio only increased after ~5.0 mm CW. Higher densities characterising seagrass areas may result in higher competition for resources, limiting growth and condition and leading to dispersal to less populated habitats. Larger juveniles had the best physiological condition, especially early in the season. Seagrass habitats do not necessarily yield enhanced growth rates and physiological condition of early juvenile crabs in relation to sandy areas. Knowledge of such trends is vital to understand distribution and abundance patterns of fish and marine invertebrate populations.
Freshwater fishes, their biodiversity, habitats and fisheries in the Nordic countries
Authors: Lehtonen Hannu , Rask Martti , Pakkasmaa Susanna , Hesthagen Trygve
Published: August 2008

Finland, Norway and Sweden have in total about 126500 lakes larger than four hectares. In Finland and Sweden, approximately 10% of the surface area is freshwater; whereas in Norway, it is about 6%. Altogether 56 fish species are reproducing in the Nordic freshwaters, including four lamprey species. Due to geographical differences, the freshwater fish fauna differs considerably in the northern and southern parts; but species richness increases also from west to east. The proportion of recreational fishermen in Norway, Finland and Sweden was about 50%, 40% and 27 %, respectively, in 2004. Professional freshwater fishing is declining, but is still important in some lakes in Finland and Sweden. In all three countries, fishing rights belong to the water or land owner, with some exceptions.

Water quality has improved in recent decades due to decreased nutrient loads from point sources, but the limitation of scattered nutrient loads has been less successful. This development can also be seen in the responses of fish communities. Some 30–40 years ago, waters close to many cities or industrial plants were heavily polluted and had only limited recreational or fisheries value. Recently, they are often inhabited by healthy fish populations. On the other hand, there are many highly eutrophic lakes in agricultural areas of southern and western Finland and Sweden that regularly suffer from algal blooms and high biomasses of cyprinid fish. The increasing acidification problem of oligotrophic lakes was related to long distance air pollution in recent years, but the situation has now improved. Lake regulation impacts the littoral ecosystems in hundreds of lakes and causes considerable negative impacts on feeding and reproduction areas for fish. The main measure used for compensating the damaged fish numbers has been stocking. Many large rivers have been modified for hydropower production. Most activities of fish habitat restoration are directed at rivers. Fisheries management includes several tools: regulations on use and structure of fishing gear, temporal and regional fishing restrictions, the size limits of target fish, the limitations of fishing efficiency, and amount of catch. The general goal is to meet the principles of sustainable use of natural resources.
Spatially resolved Hα-emission simulation with EIRENE in TJ-II to study hydrogen atomic and molecular physics in low density, high temperature fusion edge plasmas
Authors: de la Cal E. , Guasp J. , Salas A. , Reiter D. , Börner P. , Alonso J.A. , Balbín R. , Carralero D. , Hidalgo C. , de Pablos J.L. , Tabarés F.L. , Tafalla D.
Published: August 2008

This paper is a continuation of previous studies (de la Cal et al 2007 J. Nucl. Mater.
363–365 764, de la Cal et al 2007 Proc. 34th EPS Conf. (Poland, Warsaw) P 2.029), where hydrogen recycling under ionizing plasma conditions was analysed by spatially resolved Hα-emission spectroscopy with a tangentially viewing camera looking at a poloidal limiter of the TJ-II stellarator operated with a low density, high temperature plasma edge (n
e = (1–10) × 1012 cm−3 and T
e = 40–400 eV). In this study, the first objective is to validate for hydrogen the recently implemented EIRENE codea
www.eirene.de by comparing simulated Hα-emission chords with that obtained experimentally. The second objective is to analyse the atom and molecular neutral distributions in front of the limiter and at other plasma and chamber locations. The third one is to study the atomic and molecular reactions involved in the dissociation, ionization and excitation reactions, as calculated from the EIRENE code, in order to study hydrogen atomic and molecular physics in a low density, high temperature fusion plasma edge, with special focus on interpretation of Hα-emission. The contribution of the different reactions to the emission is analysed as a function of plasma radius. A relevant result obtained from EIRENE under this item is that the main precursor of the molecular Hα-emission is not H2 as proposed in many previous studies, but
.
Phase Transition and Oxygen Ion Diffusion in (La1xLnx)2Mo2O9 (Ln = Nd, Gd,x= 0.05-0.25) Using Dielectric Relaxation Method
Authors: Fang Qian-feng , Zhuang Zhong , Wang Xian-ping , Li Dan , Wang Jian-xin
Published: August 2008

Dielectric relaxation method was employed to study the properties of oxygen ion diffusion and phase transition in the oxide-ion conductors (La1xLnx)2Mo2O9 (Ln = Nd, Gd, x = 0.05-0.25). Two dielectric loss peaks were observed: peak Pd at about 600 K and peak Ph around 720 K. Peak Pd is a relaxational peak and associated with the short-range diffusion of oxygen ions, while peak Ph hardly changes its position and dramatically decreases in height with increasing frequency, exhibiting non-relaxational nature. With increasing Ln3+ concentration, the heights of peak Ph and Pd increase at first and then decrease after passing a maximum at 15% doping. It is suggested that peak Ph is related to the phase transition of a static disordered state to a dynamic disordered state in oxygen ions/vacancies distribution. It is found that the 15%Gd or 15%Nd doped La2Mo2O9 samples exhibit the highest conductivity in accordance with the highest height of peak Pd at this doping content.
Regulation of Chk1 by Its C-terminal Domain
Authors: Kosoy Ana , O'Connell Matthew J.
Published: August 2008

Chk1 is a protein kinase that is the effector molecule in the G2 DNA damage checkpoint. Chk1 homologues have an N-terminal kinase domain, and a C-terminal domain of ∼200 amino acids that contains activating phosphorylation sites for the ATM/R kinases, though the mechanism of activation remains unknown. Structural studies of the human Chk1 kinase domain show an open conformation; the activity of the kinase domain alone is substantially higher in vitro than full-length Chk1, and coimmunoprecipitation studies suggest the C-terminal domain may contain an autoinhibitory activity. However, we show that truncation of the C-terminal domain inactivates Chk1 in vivo. We identify additional mutations within the C-terminal domain that activate ectopically expressed Chk1 without the need for activating phosphorylation. When expressed from the endogenous locus, activated alleles show a temperature-sensitive loss of function, suggesting these mutations confer a semiactive state to the protein. Intragenic suppressors of these activated alleles cluster to regions in the catalytic domain on the face of the protein that interacts with substrate, suggesting these are the regions that interact with the C-terminal domain. Thus, rather than being an autoinhibitory domain, the C-terminus of Chk1 also contains domains critical for adopting an active configuration.
Microtubule-mediated Src Tyrosine Kinase Trafficking in Neuronal Growth Cones
Authors: Wu Bingbing , Decourt Boris , Zabidi Muhammad A. , Wuethrich Levi T. , Kim William H. , Zhou Zhigang , MacIsaac Keira , Suter Daniel M.
Published: August 2008

Src family tyrosine kinases are important signaling enzymes in the neuronal growth cone, and they have been implicated in axon guidance; however, the detailed localization, trafficking, and cellular functions of Src kinases in live growth cones are unclear. Here, we cloned two novel Aplysia Src kinases, termed Src1 and Src2, and we show their association with both the plasma membrane and the microtubule cytoskeleton in the growth cone by live cell imaging, immunocytochemistry, and cell fractionation. Activated Src2 is enriched in filopodia tips. Interestingly, Src2-enhanced green fluorescent protein–positive endocytic vesicles and tubulovesicular structures undergo microtubule-mediated movements that are bidirectional in the central domain and mainly retrograde in the peripheral domain. To further test the role of microtubules in Src trafficking in the growth cone, microtubules were depleted with either nocodazole or vinblastine treatment, resulting in an increase in Src2 plasma membrane levels in all growth cone domains. Our data suggest that microtubules regulate the steady-state level of active Src at the plasma membrane by mediating retrograde recycling of endocytosed Src. Expression of constitutively active Src2 results in longer filopodia that protrude from smaller growth cones, implicating Src2 in controlling the size of filopodia and lamellipodia.
Sharing the burden: antigen transport and firebreaks in immune responses
Authors: Handel Andreas , Yates Andrew , Pilyugin Sergei S , Antia Rustom
Published: August 2008

Communication between cells is crucial for immune responses. An important means of communication during viral infections is the presentation of viral antigen on the surface of an infected cell. Recently, it has been shown that antigen can be shared between infected and uninfected cells through gap junctions, connexin-based channels, that allow the transport of small molecules. The uninfected cell receiving antigen can present it on its surface. Cells presenting viral antigen are detected and killed by cytotoxic T lymphocytes. The killing of uninfected cells can lead to increased immunopathology. However, the immune response might also profit from killing those uninfected bystander cells. One benefit might be the removal of future ‘virus factories’. Another benefit might be through the creation of ‘firebreaks’, areas void of target cells, which increase the diffusion time of free virions, making their clearance more likely. Here, we use theoretical models and simulations to explore how the mechanism of gap junction-mediated antigen transport (GMAT) affects the dynamics of the virus and immune response. We show that under the assumption of a well-mixed system, GMAT leads to increased immunopathology, which always outweighs the benefit of reduced virus production due to the removal of future virus factories. By contrast, a spatially explicit model leads to quite different results. Here we find that the firebreak mechanism reduces both viral load and immunopathology. Our study thus shows the potential benefits of GMAT and illustrates how spatial effects may be crucial for the quantitative understanding of infection dynamics and immune responses.
Anomalous diffusion of heterogeneous populations characterized by normal diffusion at the individual level
Authors: Hapca Simona , Crawford John W , Young Iain M
Published: August 2008

The characterization of the dispersal of populations of non-identical individuals is relevant to most ecological and epidemiological processes. In practice, the movement is quantified by observing relatively few individuals, and averaging to estimate the rate of dispersal of the population as a whole. Here, we show that this can lead to serious errors in the predicted movement of the population if the individuals disperse at different rates. We develop a stochastic model for the diffusion of heterogeneous populations, inspired by the movement of the parasitic nematode
Phasmarhabditis hermaphrodita
. Direct observations of this nematode in homogeneous and heterogeneous environments reveal a large variation in individual behaviour within the population as reflected initially in the speed of the movement. Further statistical analysis shows that the movement is characterized by temporal correlations and in a heterogeneously structured environment the correlations that occur are of shorter range compared with those in a homogeneous environment. Therefore, by using the first-order correlated random walk techniques, we derive an effective diffusion coefficient for each individual, and show that there is a significant variation in this parameter among the population that follows a gamma distribution. Based on these findings, we build a new dispersal model in which we maintain the classical assumption that individual movement can be described by normal diffusion, but due to the variability in individual dispersal rates, the diffusion coefficient is not constant at the population level and follows a continuous distribution. The conclusions and methodology presented are relevant to any heterogeneous population of individuals with widely different diffusion rates.
Influence of automated screening and confirmation of extended-spectrum β-lactamase-producing members of the Enterobacteriaceae on prescribing of antibiotics
Authors: Nicasio Anthony M. , Kuti Joseph L. , Aslanzadeh Jaber , Nicolau David P.
Published: August 2008

This study investigated the clinician response to the extended-spectrum β-lactamase (ESBL) confirmation report generated by an automated detection system, MicroScan Walkaway. The study compared two cohorts (pre- and post-automated detection) of patients with an ESBL-producing Escherichia coli or Klebsiella species non-urinary infection over the period October 2001–December 2006. Acceptance of the report, as defined by the initiation of carbapenem therapy, was observed in 69.2 % of the post-automated detection cohort (n=78) versus 20 % in the pre-automated detection period (n=15) (P ≤0.001). The utilization of a carbapenem increased progressively over the course of the study. Moreover, the time to initiation of carbapenem therapy was reduced from 15.7±4.9 to 0.1±2.0 days (P ≤0.001) after implementation of this automated detection system. Overall, clinicians responded positively to the ESBL automated detection report, as gauged by the increased utilization of a carbapenem and the earlier initiation of appropriate therapy; however, reductions in length of stay and mortality were not observed in this infected population.
Acanthamoeba and the blood–brain barrier: the breakthrough
Authors: Khan Naveed Ahmed
Published: August 2008

Acanthamoeba granulomatous encephalitis is a rare disease that almost always proves fatal. Death occurs mainly due to neurological complications; however, the pathogenesis and pathophysiology associated with this disease remain incompletely understood. Haematogenous spread is a key step in the development of Acanthamoeba encephalitis, but it is not clear how circulating amoebae breakthrough the blood–brain barrier to gain entry into the central nervous system to produce the disease. This review of the literature describes the parasite factors and immune-mediated mechanisms involved in the blood–brain barrier dysfunction leading to neuropathogenesis.
Graft versus host disease-related Hafnia alvei colonization and probable infection
Authors: Savini Vincenzo , Di Bartolomeo Erminia , Catavitello Chiara , Talia Marzia , Manna Assunta , Febbo Fabio , Balbinot Andrea , Di Bonaventura Giovanni , Di Bartolomeo Paolo , Piccolomini Raffaele , D'Antonio Domenico
Published: August 2008

We describe the case of a graft versus host disease (GvHD) patient, in whom Hafnia alvei was cultured as a single organism, and at high bacterial counts from stool samples, from the onset of the disease until its resolution. This case is a further example of the contentious role of this species in causing human intestinal disease. Furthermore, it focuses on enteric damage by GvHD as a risk factor for acquiring H. alvei colonization, and probably infection.
Differential glycosaminoglycan binding of Chlamydia trachomatis OmcB protein from serovars E and LGV
Authors: Fadel Sanaa , Eley Adrian
Published: August 2008

We recently showed that OmcB protein from Chlamydia trachomatis serovar LGV1 functions as an adhesin. In this study, we produced Escherichia coli expressing OmcB from serovar E and compared this OmcB to OmcB from serovar LGV1. Infectivity inhibition assays carried out with serovars LGV1 and E of C. trachomatis in the presence of recombinant OmcB showed considerable (∼60 %) inhibition of infectivity. In the presence of heparan sulphate, there was significant inhibition (68 %) of adherence of E. coli expressing OmcB from serovar LGV1 only. In a further experiment, recombinant OmcB from serovar LGV1 showed minimal binding to glycosaminoglycan (GAG)-deficient cells, whilst to the same cells, recombinant OmcB from serovar E showed binding equal to that to the wild-type cells. Our experiments strongly suggest that OmcB from serovar E, in contrast to that from serovar LGV1, is not binding to host cells through a GAG-dependent mechanism.
Comparative prevalence of superantigenic toxin genes in meticillin-resistant and meticillin-susceptible Staphylococcus aureus isolates
Authors: Hu Dong-Liang , Omoe Katsuhiko , Inoue Fumio , Kasai Takesi , Yasujima Minoru , Shinagawa Kunihiro , Nakane Akio
Published: August 2008

A total of 118 meticillin-resistantStaphylococcus aureus(MRSA) and 140 meticillin-susceptibleS. aureus(MSSA) isolates from different patients in the same time period were comprehensively searched using a multiplex PCR for the classical and recently described superantigenic toxin gene family comprising the staphylococcal enterotoxin genesseatoserand the toxic shock syndrome toxin 1 gene,tst-1. Both MRSA and MSSA isolates carried a number of superantigenic toxin genes, but the MRSA isolates harboured more superantigenic toxin genes than the MSSA isolates. The most frequent genotype of the MRSA isolates wassec,sellandtst-1together with the gene combinationseg,sei,selm,selnandselo, which was found strictly in combination in 69.5 % of the isolates tested. In contrast, possession of thesec,sellandtst-1genes in MSSA isolates was significantly less than in MRSA (2.1 vs 77.1 %, respectively), although they also often contained the combination genes (25.0 %). This notable higher prevalence in MRSA isolates indicated that possession of thesec,sellandtst-1genes in particular appeared to be a habitual feature of MRSA. Moreover, these were mainly due to the fixed combinations of the mobile genetic elements type I νSa4 encodingsec,sellandtst-1, and type I νSaβencodingseg,sei,selm,selnandselo. Analysis of the relationship between toxin genotypes and the toxin gene-encoding profiles of mobile genetic elements has a possible role in determining superantigenic toxin genotypes inS. aureus.
A dedicated software for aircraft sheet metal parts
Authors: Sedighi M. , Abolghasemi M.S.
Published: August 2008

Purpose

Traditional procedures in flat pattern design of aircraft sheet metal parts are generally based on technicians' personal idea and experiences which can cause unwanted inconsistency and errors. The main objective of this paper is to present an automated system for decreasing the time and increasing the accuracy in providing templates used in aircraft sheet metal parts manufacturing.

Design/methodology/approach

The paper discusses the software (Developer) which is able to receive 2D drawing of a part and create the flat pattern template after applying the necessary changes. The system is also capable of supplying other components of sheet metal part template such as support, tooling hole, and lightening hole. AutoLISP has been used as a tool for internal access to a commercial software such as AutoCAD. An interface has been written by Visual Basic for Application (VBA) to enable the user easily to apply the subroutines related to the software system.

Findings

Several algorithms have been developed and the necessary subroutines have been written in an integrated user‐friendly package. To clarify the process and its application, an application example is demonstrated.

Originality/value

The paper can provide automatically components that are not originally provided in other commercial software. It also has the ability to calculate spring‐back and provide unfold drawing. The known standard templates can also be created.
Workpiece temperature prediction by model and measurement by pyrometer
Authors: Longbottom J.M. , Dailami F.
Published: August 2008

Purpose

This paper aims to examine the use of a commercial pyrometer to measure the surface temperature of workpieces as machining takes place. The pyrometer readings are to be compared with model predictions.

Design/methodology/approach

The pyrometer was mounted on an industrial milling machine and the temperature of the workpiece was measured behind the cutting tool as it traversed the workpiece. A mathematical spreadsheet model was used to predict the temperatures at the point measured by the pyrometer and at the point where cutting took place.

Findings

It was found by selecting the “partition ratio” of the power being transmitted to the workpiece that agreement could be found between measured and predicted results.

Research limitations/implications

The work was mainly carried out on aluminium samples, which exhibited low cutting temperatures.

Originality/value

The paper describes a method of finding the partition ratio of heat going into the workpiece.
Effect of humic acid on the corrosion behavior of carbon steel in natural freshwaters
Authors: Jiang Li , Mao Xuhui , Yu Jianfei , Gan Fuxing
Published: August 2008

Purpose

The purpose of this paper is to study corrosion behavior and corrosion mechanism of carbon steel in natural freshwaters with humic acid (HA).

Design/methodology/approach

The weight‐loss method, electrochemical measurements and surface analysis technique were used to study the corrosion behavior of carbon steel in freshwaters with HA.

Findings

General corrosion occurred when carbon steel was exposed to test solutions (fresh lake water with and without HA). The presence of HA in test solution can accelerated the corrosion rate of carbon steel.

Originality/value

There have been few reports on the effect of HA on the corrosion behavior of carbon steel. In this study, it is clearly shown that the presence of HA in fresh lake water can accelerate the corrosion rate of carbon steel. This research not only can offer theoretical guidelines for the prevention of pipelines and facilities from corroding, but also can provide a reference for suitable material selection and the further protection of carbon steel in hydraulic engineering.
Assessing export performance in the Greek food and beverage industry
Authors: Mavrogiannis Miltiadis , Bourlakis Michael A. , Dawson Philip J. , Ness Mitchell R.
Published: August 2008

Purpose

The purpose of this paper is to develop and estimate an integrated empirical model of export performance. The paper aims to adopt an eclectic approach, which synthesises the literature to identify key determinants and then applies the model to Greek food and beverage exporters.

Design/methodology/approach

This paper identifies the determinants of export performance from a literature review. An integrated structural equation model is then developed to estimate the directions and magnitudes of their interdependencies.

Findings

Results show that the determinants of export performance are the export marketing mix, entrepreneurial orientation, trade barriers and export problems. In turn, the export marketing mix is indirectly determined by export market attractiveness, export competencies, and management.

Practical implications

The multidimensional approach of this paper provides for a more integrated understanding of export performance than many of the partial studies found in the literature hitherto.

Originality/value

The paper identifies generic factors that are important for successful export marketing. These are incorporated into a structural equation model, which estimates their impacts and interdependencies on export performance simultaneously. The findings can aid Greek food and beverage exporters to formulate effective export marketing strategies.
Segmentation of US consumers based on food safety attitudes
Authors: Kennedy Jean , Worosz Michelle , Todd Ewen C. , Lapinski Maria K.
Published: August 2008

Purpose

The purpose of this research paper is to segment US consumers based on their attitudes towards food safety and to demographically characterize each segment so that effective risk communication strategies and outreach programs may be developed to target vulnerable groups.

Design/methodology/approach

Factor analysis and hierarchical cluster analysis were applied to data on consumer food safety attitudes of a probability sample of US adults, collected by telephone questionnaires (n=1,014).

Findings

The diversity of consumer attitudes was based on five factors; concern, trust, desire for a high level of regulation, acceptance for the number of people who are ill, hospitalized or die from foodborne illness, and preference for the right to purchase foods that are not guaranteed to be safe. The consumer segments identified on the bases of these factors can be classified as “confident,” “independent”, “trusting”, “cautious”, or “apprehensive” consumers. Socio‐demographic characteristics; education, income, person with allergy in the household, and person under the age of six living in the household, varied significantly between each consumer segment.

Practical implications

This study can inform effective food safety intervention strategies and target consumers most in need of food safety education that may enhance overall food safety knowledge and/or lead to changes in their behavior.

Originality/value

This paper uses exploratory factor analysis to identify the factors that underlie consumers' attitudes towards food safety. It is the first study to segment US consumers based on these factors and to demographically characterize each segment.
Asceticism and hedonism in research discourses of veg*anism
Authors: Cole Matthew
Published: August 2008

Purpose

The purpose of this paper is to critically examine the dominance of an ascetic discourse of veg*anism in social research literature, and to relate it to a dominant hierarchical ordering of Western diets (to refer collectively to veganism and vegetarianism).

Design/methodology/approach

A review of the extant social research literature on veg*anism was undertaken in order to discern whether a consistent type of descriptive language existed. This facilitated an understanding of the way in which that language is constitutive of research generated understandings of veg*anism.

Findings

An ascetic discourse of veg*anism is dominant in social research. This is reflected in the phraseology used by authors. Typical descriptive terms of a veg*an diet include “strict”, “restrictive”, or “avoidance”. This ascetic discourse reproduces the hierarchical ordering of Western diets such that veg*anism is denigrated and made to seem “difficult” and abnormal.

Research limitations/implications

Veg*anism arguably promises multiple benefits for human, environmental, and nonhuman animal well‐being. The potential to realize those benefits is hampered by the perpetuation of an understanding of veg*anism as an ascetic practice.

Originality/value

This paper provides the first comprehensive examination of the language used to describe veg*anism within social research. It can enhance reflexivity on the part of social researchers interested in veg*anism, and help inform research design. In providing an alternative hedonic discourse of veg*anism, this paper also makes a contribution towards realizing the potential benefits of veg*anism through making it a more attractive dietary practice.
Effect of probiotics on biotechnological characteristics of yoghurt
Authors: Sarkar S.
Published: August 2008

Purpose

Probiotics are known to extend health benefits and therefore may be included during yoghurt manufacture to enhance its prophylactic properties. Different probiotic strains may exhibit diverse biotechnological behaviour in association with yoghurt cultures, therefore interactive behaviour amongst probiotic and yoghurt cultures must be evaluated prior to their commercial application. This paper aims to assess the effect of inclusion of different probiotic cultures on various biotechnological (technological, dietetic and prophylactic) characteristics of yoghurt cultures.

Design/methodology/approach

Yoghurt was assessed for technological characteristics based on acidification and flavour production, dietetic characteristics based on proteolytic activity, vitamin synthesis and L (+) lactic acid production and prophylactic characteristics based onβ‐galactosidase activity, antibacterial spectrum, viability in product as well as during gastro‐intestinal transit, intestinal colonization, immunomodulation, anti‐carcinogenicity and hypocholesterolemic effect.

Findings

Different probiotic cultures exhibited diverse technological, dietetic and prophylactic behaviour in association with yoghurt cultures. Functional properties of traditional yoghurt could be enhanced with the combined introduction of probiotic cultures such asBifidobacterium bifidum,Bifidobacterium infantisandLactobacillus acidophilusand the resultant product may be recommended for consumption as a dietary adjunct.

Originality/value

The paper shows that combined introduction of probiotic cultures such asB. bifidum,B. infantisandL. acidophilus,as microbial additives during the manufacture of yoghurt would result in a product with enhanced functional properties.
Understanding and addressing bullying in the workplace
Authors: Townend Anni
Published: August 2008

Purpose

The purpose of this paper is to better understand bullying behaviours in the workplace and how these behaviours can be addressed as part of an ongoing and integral approach to diversity through building bigger and more assertive relationships in which there is greater awareness and understanding of each other – our differences and similarities

Design/methodology/approach

A psychological approach is taken in order to better understand the phenomena of bullying and the kinds of interventions that can facilitate individuals, groups and organisations in becoming more inclusive and assertive

Findings

Incidents of bullying behaviour in organisations towards people most typically are directed at individuals from the very groups of people who are regularly targeted for bullying simply for being different from the majority and not because of something that they have done or not done

Originality/value

A deeper understanding of the dynamics of bullying behaviour in organisations leading to suggestions as to how organisations can promote attitudes, values and behaviours that are inclusive and allowing of difference.
An epistemological critique of gap theory based library assessment: the case of SERVQUAL
Authors: Yu Liangzhi , Hong Qiulan , Gu Song , Wang Yazun
Published: August 2008

Purpose

The purpose of this paper is twofold: first, to investigate the epistemological underpinning of SERVQUAL and its limitations; and second, to propose ways to enhance the utility of SERVQUAL as a library assessment tool.

Design/methodology/approach

The study first conceptualises quality judgment as a knowing process and locates the epistemological stance of SERVQUAL within the general framework of epistemology demarcation; it then examines related SERVQUAL assumptions and their implications for library assessment in general and for service quality assessment in particular based on two empirical investigations: a questionnaire survey and an interview survey. The questionnaire survey applies the SERVQUAL instrument to three Chinese university libraries, with a view to examining the SERVQUAL score in light of epistemological considerations; the interview survey interviews 50 faculty users in one of the three universities with a view to illuminating the naturalistic process through which users develop their judgement of the library's service quality and through which the SERVQUAL score is formed.

Findings

The study shows that the actual SERVQUAL score is distributed in a very scattered manner in all three libraries, and that it is formed through a very complex process rooted primarily in the user's personal experiences with the library, which are in turn shaped by factors from both the library world and the user's life‐world. Based on these findings, this research questions a number of SERVQUAL assumptions and proposes three concepts which may help to contextualise the SERVQUAL score and enhance its utility in actual library assessment: library planning based variance of user perception, perception‐dependent user expectation and library‐sophistication based user differentiation.

Originality/value

The research presented in the paper questions a number of SERVQUAL assumptions and proposes three concepts that may help to contextualise the SERVQUAL score and enhance its utility in actual library assessment.