bluuebunny/crossref_metadata_2025 huggingface dataset:
Debye size microprobes for electric field measurements in laboratory plasmas
Authors: Pribyl P. , Gekelman W. , Nakamoto M. , Lawrence E. , Chiang F. , Stillman J. , Judy J. , Katz N. , Kintner P. , Niknejadi P.
Published: July 2006

Microelectromechanical systems (MEMS) have led to the development of a host of tiny machines and sensors over the past decade. Plasma physics is in great need of small detectors for several reasons. First of all, very small detectors do not disturb a plasma, and secondly some detectors can only work because they are very small. We report on the first of a series of small (sub-Debye length) probes for laboratory plasmas undertaken at the basic Plasma Science Facility at UCLA. The goal of the work is to develop robust and sensitive diagnostic probes that can survive in a plasma. The probes must have electronics packages in close proximity. We report on the construction and testing of probes that measure the electric field.
Ion-induced multiply reentrant liquid-liquid transitions and the nature of criticality in ethanol-water mixture
Authors: Bagchi Debjani , Kumar Anil , Menon Reghu
Published: July 2006

We report a quite unusual feature of four liquid-liquid reentrant transitions in ethanol (E)+water (W)+ammonium sulfate mixture by meticulous tuning of the ammonium sulfate concentration in a narrow range, as a function of temperature, at atmospheric pressure. Detailed exploration of the intricate phase behavior in terms of E/W sections shows that the range of triple reentrance shrinks with increasing E/W. The behavior of osmotic susceptibility is investigated by light scattering, near the critical point, in the one-phase region by varying the temperature at fixed concentration of the components, in a particular E/W section. The critical exponent of susceptibility (γ) and correlation length (ν) are observed to have Fisher renormalized Ising values [Phys. Rev. 176, 237 (1968)], with γr=1.41 and νr=0.718. The effective susceptibility exponent, γeff, exhibits a sharp, nonmonotonic crossover from Ising to mean-field critical behavior, which is completed outside the critical regime. The amplitude of the correlation length, ξo(=21.2±0.4Å), deduced from light scattering experiment, is an order of magnitude larger than the typical values in usual aqueous electrolyte systems. This value of ξo is further verified from small-angle x-ray scattering (SAXS) experiments and found to be consistent. SAXS experiments on the critical sample reveal the presence of long-ranged intermolecular correlations, leading to supramolecular structuring, at a temperature far away from the critical point. These results convincingly demonstrate that the finite length scale arising due to the structuring competes with the diverging correlation length of critical concentration fluctuations, which influences the nonasymptotic critical behavior in this aqueous electrolyte system. The sulphate ions play a dominant role in both structuring and the complex phase behavior.
A theoretical analysis on hydration thermodynamics of proteins
Authors: Imai Takashi , Harano Yuichi , Kinoshita Masahiro , Kovalenko Andriy , Hirata Fumio
Published: July 2006

The hydration free energy (HFE) of several proteins modeled using the all-atom force field is calculated by employing the three-dimensional reference interaction site model theory, a recently developed integral equation theory of molecular solvation. The HFE is decomposed into the energetic and entropic components under the isochoric condition. The former comprises the protein-water interaction energy and the water reorganization energy arising from the structural changes induced in water. Each component is further decomposed into the nonelectrostatic and electrostatic contributions. It is found that the HFE is governed by the nonelectrostatic hydration entropy and the electrostatic hydration energy. The nonelectrostatic hydration entropy is almost exclusively ascribed to the translational entropy loss of water upon the protein insertion. It asymptotically becomes proportional to the excluded volume (EV) for water molecules as the protein size increases. The hydration energy is determined by the protein-water interaction energy which is half compensated by the water reorganization energy. These energy terms are approximately proportional to the water-accessible surface area (ASA). The energetic and entropic contributions are balanced with each other and the HFE has no apparent linear relation with the EV and ASA.
Study on the intermolecular interaction of C60 and simulations on the orientational properties of C60 in crystals
Authors: Kita Yukiumi , Wako Kei , Goto Hiromitsu , Naito Takeshi , Kawai Hidemi , Okada Isamu
Published: July 2006

We developed the new intermolecular interaction model of C60 with the quantitative accuracy for the molecular orientational properties in crystals. The energy difference (ΔE) and the activation barrier (Ebarrier) between the two stable orientations (P and H orientations) in crystals are in the values of +14.7 and +260meV in our model, respectively; these values are in fairly good agreement with the experimental values (ΔE≃+11meV, Ebarrier=+235–+290meV in experiments). The relaxation calculation for C60 crystals using our model revealed that there is the reversal of the stable orientations between the P and H orientations under the high H-orientation occupancy (pH) in crystals, when pH>0.83, ΔE<0. From the molecular dynamics calculations for C60 crystals using our model, it is found that the phase transition is induced at TC=200–260K, which is consistent with the experimental value of 260K. Immediately below TC, we found a great variety of molecular rotational jumps involving that between the P and H orientations every about 10−9s due to the thermal activation. In the high temperature phase (>TC), all molecules rotate irregularly like in Brownian motion involving the rotational “slumber” for ≃10−12–10−11s.
An interaction site model integral equation study of molecular fluids explicitly considering the molecular orientation
Authors: Sumi Tomonari , Sekino Hideo
Published: July 2006

We implemented an interaction site model integral equation for rigid molecules based on a density-functional theory where the molecular orientation is explicitly considered. In this implementation of the integral equation, multiple integral of the degree of freedom of the molecular orientation is performed using efficient quadrature methods, so that the site-site pair correlation functions are evaluated exactly in the limit of low density. We apply this method to Cl2, HCl, and H2O molecular fluids that have been investigated by several integral equation studies using various models. The site-site pair correlation functions obtained from the integral equation are in good agreement with the one from a simulation of these molecules. Rotational invariant coefficients, which characterize the microscopic structure of molecular fluids, are determined from the integral equation and the simulation in order to investigate the accuracy of the integral equation.
Electronic states and potential energy curves of molybdenum carbide and its ions
Authors: Denis Pablo A. , Balasubramanian K.
Published: July 2006

The potential energy curves and spectroscopic constants of the ground and 29 low-lying excited states of MoC with different spin and spatial symmetries within 48000cm−1 have been investigated. We have used the complete active space multiconfiguration self-consistent field methodology, followed by multireference configuration interaction (MRCI) methods. Relativistic effects were considered with the aid of relativistic effective core potentials in conjunction with these methods. The results are in agreement with previous studies that determined the ground state as XΣ−3. At the MRCISD+Q level, the transition energies to the 1Δ3 and 4Δ1 states are 3430 and 8048cm−1, respectively, in fair agreement with the results obtained by DaBell et al. [J. Chem. Phy. 114, 2938 (2001)], namely, 4003 and 7834cm−1, respectively. The three band systems located at 18 611, 20 700, and 22520cm−1 observed by Brugh et al. [J. Chem. Phy. 109, 7851 (1998)] were attributed to the excited 11Σ−3, 14Π3, and 15Π1 states respectively. At the MRCISD level, these states are 17 560, 20 836, and 20952cm−1 above the ground state respectively. We have also identified a Π3 state lying 14309cm−1 above the ground state. The ground states of the molecular ions are predicted to be Σ−4 and Δ2 for MoC− and MoC+, respectively.
Including quantum subsystem character within classical equilibrium simulations
Authors: Gomez Maria A. , Peart Patricia
Published: July 2006

A mixed quantum/classical density matrix approximation is derived. The density matrix makes use of quantum subsystem vibrational wave functions. The diagonal of the density matrix can be used as an equilibrium distribution in Monte Carlo simulations. The approximate distribution compares well with the path integral distribution for a model system. Since it includes quantum subsystem information, it performs much better than the quadratic Feynman-Hibbs distribution. These types of distributions can aid in including quantum vibrational information in otherwise classical simulations.
Resolving the emission times of solute and solvent four-wave mixing signals by spectral interferometry
Authors: Moran Andrew M. , Nome Rene A. , Scherer Norbert F.
Published: July 2006

Electric field-resolved transient grating measurements are used to distinguish the four-wave mixing signal emission from a resonant solute and a non-resonant solvent. The two components of the solution (i.e., solute and solvent) emit signal fields at different times with respect to the arrival of the probe pulse to the sample. This gives rise to a recurrence in the temporal profile of the total signal field. We show that the origin of this interference is the difference in relaxation time scales of the holographic gratings associated with the solute and solvent. The grating of the resonant solute relaxes on the time scale of a few picoseconds due to depopulation of its excited electronic state, whereas the electronic polarizability response of the solvent relaxes on the femtosecond time scale. This separability of responses is a general phenomenon that is particularly useful for studying weakly absorbing solute dynamics in polarizable solvents.
Real-time recovery of the electron density from interferometric measurements affected by fringe jumps
Authors: Murari A. , Zabeo L. , Boboc A. , Mazon D. , Riva M.
Published: July 2006

Optical interferometers are normally used in magnetically confined plasmas to measure the refractive index of the plasma by comparing the phase shift variation between a reference and a probe laser beam, from which the line-integrated electron density can be derived. Unfortunately, interferometric measurements are affected by fringe jumps, which are basically the erroneous phase difference determination due to the loss of signals or a phase difference bigger than 2π. The multiple causes include the refraction, wavelength of the laser radiation used, sensitivity, and time resolution of the measurements. On the other hand, the plasma density has become an essential piece of information for many real-time control schemes, which can therefore be completely jeopardized by fringe jumps. To overcome this problem at JET two main approaches can be adopted. The first approach consists of performing a real-time correction of the affected chords, eliminating the spurious effect of the fringe jumps, and providing a corrected line integral of acceptable quality. This is done at JET by complex algorithms that have inputs of various interferometry and polarimetry measurements.

A second approach can be adopted based on the observation that, for many real-time experiments, an approximate estimate of the density profile is sufficient. In JET, it was demonstrated that the density profile of the vast majority of configurations could be determined with sufficient accuracy by using only the line-integrated density profile provided by two chords; one external and one internal. The various solutions were tested and results compared in order to verify the most suitable one for the various plasma configurations and operational scenarios. A “general purpose” version of the correction algorithm was implemented and is now normally running during JET operation.
Gas-phase femtosecond transient absorption spectroscopy
Authors: Chen Hsueh-Ying , Lee I-Ren , Cheng Po-Yuan
Published: July 2006

A setup for measuring femtosecond transient absorption in the gas phase is reported. The apparatus is based on a 1kHz amplified Ti:sapphire laser system and measures gas-phase transient absorption using a shot-to-shot normalization scheme with background subtraction. We have used this setup to examine the wave packet dynamics of the I2 B state in the vapor phase as a benchmark. The results are consistent with those reported by other groups using indirect transient absorption techniques.
Alloy disorder effects on the room temperature optical properties of Ga1−xInxNyAs1−y quantum wells
Authors: Bansal Bhavtosh , Kadir Abdul , Bhattacharya Arnab , Arora B. M. , Bhat Rajaram
Published: July 2006

The effect of alloy disorder on optical density of states and average room-temperature carrier statistics in Ga1−xInxNyAs1−y quantum wells is discussed. A redshift between the peak of the room-temperature photoluminescence and the surface photovoltage spectra that systematically increases with nitrogen content y is observed. The relationship between this Stokes shift and the absorption linewidth in different samples suggests that the photoexcited carriers undergo a continuous transition—from quasithermal equilibrium with the lattice to complete trapping by quantum dot like potential fluctuations—with increase in nitrogen fraction. The “electron temperatures” inferred from photoluminescence spectra are consistent with this interpretation.
Er
3
+
excited state absorption and the low fraction of nanocluster-excitable Er3+ in SiOx
Authors: Oton C. J. , Loh W. H. , Kenyon A. J.
Published: July 2006

Despite the observation by a number of groups of a strong luminescence sensitization effect of erbium ions by excitation exchange from silicon nanoclusters, there is considerable experimental evidence that the fraction of Er ions excited by Si-nc is actually very low for much of the material reported. In this work, we examine the evidence and point out that Er excited state absorption is the likely cause.
Mirrorless lasing from nematic liquid crystals in the plane waveguide geometry without refractive index or gain modulation
Authors: Blinov L. M. , Cipparrone G. , Pagliusi P. , Lazarev V. V. , Palto S. P.
Published: July 2006

Lasing from dye doped liquid crystals was observed in the nematic and isotropic phases in the plane waveguide geometry without mirrors and special modulation of the gain or refraction index by a holographic or other technique. The light was generated in a liquid crystal layer confined by two glasses with semitransparent electrodes, which formed an optical waveguide. A strong light amplification occurred along the length of a narrow stripe produced by the pump beam with the necessary feedback provided by the walls of the waveguide in the direction perpendicular to the stripe. The conditions for lasing were fulfilled for the lowest group velocity waveguide modes bouncing at the angles very close to the total reflection angle at the waveguide-glass interface. These modes leaked into the glasses were guided therein at very grazing angles and left the cell from its edges.
Direct stimulation of T cells by membrane vesicles from antigen-presenting cells
Authors: Kovar Marek , Boyman Onur , Shen Xuefei , Hwang Inkyu , Kohler Rachel , Sprent Jonathan
Published: July 2006

Activation of naïve T cells generally requires T cell receptor-mediated contact with MHC-bound peptides on viable antigen-presenting cells such as dendritic cells (DC). Here evidence is presented that dissociated cell membrane fragments from a DC line can be used as an effective substitute for viable DC. Ultracentrifuged material derived from sonicates of IFN-γ-matured DC is enriched in small membrane vesicles that closely resemble exosomes. When complexed with MHC class I-restricted specific peptide, vesicles from DC sonicates generate strong responses by purified naïve CD8+cellsin vitroin the absence of normal antigen-presenting cells and can also efficiently prime T cells for tumor rejectionin vivo. Both in terms of total yields from DC and relative immunogenicity, membrane vesicles from DC sonicates are much more effective than classic exosomes and may be a valuable tool for tumor immunotherapy.
RNA Interference Knockdown of hU2AF35Impairs Cell Cycle Progression and Modulates Alternative Splicing of Cdc25 Transcripts
Authors: Pacheco Teresa Raquel , Moita Luís Ferreira , Gomes Anita Quintal , Hacohen Nir , Carmo-Fonseca Maria
Published: July 2006

U2AF is a heterodimeric splicing factor composed of a large (U2AF65) and a small (U2AF35) subunit. In humans, alternative splicing generates two U2AF35variants, U2AF35a and U2AF35b. Here, we used RNA interference to specifically ablate the expression of each isoform in HeLa cells. Our results show that knockdown of the major U2AF35a isoform reduced cell viability and impaired mitotic progression, leading to accumulation of cells in prometaphase. Microarray analysis revealed that knockdown of U2AF35a affected the expression level of ∼500 mRNAs, from which >90% were underrepresented relative to the control. Among mRNAs underrepresented in U2AF35a-depleted cells we identified an essential cell cycle gene, Cdc27, for which there was an increase in the ratio between unspliced and spliced RNA and a significant reduction in protein level. Furthermore, we show that depletion of either U2AF35a or U2AF35b altered the ratios of alternatively spliced isoforms of Cdc25B and Cdc25C transcripts. Taken together our results demonstrate that U2AF35a is essential for HeLa cell division and suggest a novel role for both U2AF35protein isoforms as regulators of alternative splicing of a specific subset of genes.
A Golgi-localized Hexose Transporter Is Involved in Heterotrimeric G Protein-mediated Early Development inArabidopsis
Authors: Wang Helen X. , Weerasinghe Ravisha R. , Perdue Tony D. , Cakmakci Nihal G. , Taylor J. Philip , Marzluff William F. , Jones Alan M.
Published: July 2006

Signal transduction involving heterotrimeric G proteins is universal among fungi, animals, and plants. In plants and fungi, the best understood function for the G protein complex is its modulation of cell proliferation and one of several important signals that are known to modulate the rate at which these cells proliferate is d-glucose. Arabidopsis thaliana seedlings lacking the β subunit (AGB1) of the G protein complex have altered cell division in the hypocotyl and are d-glucose hypersensitive. With the aim to discover new elements in G protein signaling, we screened for gain-of-function suppressors of altered cell proliferation during early development in the agb1-2 mutant background. One agb1-2-dependent suppressor, designated sgb1-1Dfor suppressor of G protein beta1 (agb1-2), restored to wild type the altered cell division in the hypocotyl and sugar hypersensitivity of the agb1-2 mutant. Consistent with AGB1 localization, SGB1 is found at the highest steady-state level in tissues with active cell division, and this level increases in hypocotyls when grown on d-glucose and sucrose. SGB1 is shown here to be a Golgi-localized hexose transporter and acts genetically with AGB1 in early seedling development.
Chs5/6 Complex: A Multiprotein Complex That Interacts with and Conveys Chitin Synthase III from theTrans-Golgi Network to the Cell Surface
Authors: Sanchatjate Siraprapha , Schekman Randy
Published: July 2006

In Saccharomyces cerevisiae, the polysaccharide chitin is deposited at the mother bud junction by an integral membrane enzyme, chitin synthase 3 (Chs3p). The traffic of Chs3p to the cell surface from the trans-Golgi network (TGN) depends on two proteins, Chs5p and Chs6p, which sort selected cargo proteins into secretory vesicles. We have found that Chs5p forms a large higher-order complex of around 1 MDa with Chs6p and three Chs6 paralogs: Bch1p, Bud7p, and Bch2p. The Chs5/6 complex transiently interacts with its cargo, Chs3p, and the presence of Chs3p in the complex is dependent on every subunit. Chs5p and Chs6p have unique and crucial roles in Chs3p transport because either a chs5Δ or chs6Δ mutant drastically reduces the level of Chs3p bound to the remaining subunits of the complex. Bch1p and Bud7p appear to have a redundant function in Chs3p transport because deletion of both is necessary to displace Chs3p from the complex. The role of Bch2p in Chs3p binding is the least important. Chs5p is essential for structural integrity of the Chs5/6 complex and may act as a scaffold through which the other subunits assemble. Our results suggest a model of protein sorting at the TGN that involves a peripheral, possibly coat, complex that includes multiple related copies of a specificity determining subunit.
Inbreeding and disease resistance in a social insect: effects of heterozygosity on immunocompetence in the termite
Zootermopsis angusticollis
Authors: Calleri Daniel V , McGrail Reid Ellen , Rosengaus Rebeca B , Vargo Edward L , Traniello James F.A
Published: July 2006

Recent research has shown that low genetic variation in individuals can increase susceptibility to infection and group living may exacerbate pathogen transmission. In the eusocial diploid termites, cycles of outbreeding and inbreeding characterizing basal species can reduce genetic variation within nestmates during the life of a colony, but the relationship of genetic heterogeneity to disease resistance is poorly understood. Here we show that, one generation of inbreeding differentially affects the survivorship of isolated and grouped termites (
Zootermopsis angusticollis)
depending on the nature of immune challenge and treatment. Inbred and outbred isolated and grouped termites inoculated with a bacterial pathogen, exposed to a low dose of fungal pathogen or challenged with an implanted nylon monofilament had similar levels of immune defence. However, inbred grouped termites exposed to a relatively high concentration of fungal conidia had significantly greater mortality than outbred grouped termites. Inbred termites also had significantly higher cuticular microbial loads, presumably due to less effective grooming by nestmates. Genetic analyses showed that inbreeding significantly reduced heterozygosity and allelic diversity. Decreased heterozygosity thus appeared to increase disease susceptibility by affecting social behaviour or some other group-level process influencing infection control rather than affecting individual immune physiology.
Photosensitive neurogenic heart of the isopod crustaceanLigia exotica
Authors: Miyamoto Hiroshi , Horiguchi Hiroko , Hariyama Takahiko , Takano Satoshi , Yamagishi Hiroshi
Published: July 2006

The heart of animals is regulated through the central nervous system in response to external sensory stimuli. We found, however, that the adult neurogenic heart of the isopod crustaceanLigia exoticahas photosensitivity. The beat frequency of the isolated heart decreased in response to a light stimulus. Magnitude of the response was stimulus intensity dependent and the heartbeat frequency decreased to less than 80% of the dark value during illumination of the white light with an intensity of 6.0 mW cm−2. The spectral sensitivity curve of the heart photoresponse peaked at a wavelength around 520 nm. In response to 530 nm monochromatic light, the relationship between light intensity and response magnitude was linear and the threshold intensity was 7.26×1012 quanta cm−2 s−1. Bursting activity of the cardiac ganglion, which is located in the heart and acts as the cardiac pacemaker deceased in frequency in response to illumination by white light. This fact suggests that the heart photoresponse ofL. exoticaresults from the photosensitivity of the cardiac ganglion neurons. The photoresponse of the heart therefore contributes to regulation of cardiac output in addition to other regulatory systems.
Phased rotation, conformation and translation function: theory and computer program
Authors: Pavelcik Frantisek
Published: July 2006

A new crystallographic function, phased rotation conformation and translation (PRCTF), has been developed. The function is designed for automatic interpretation of electron density utilizing molecular fragments with some conformational freedom. A computer program,NUT, has been written for the calculation of the PRCTF.
Mammalian target of rapamycin inhibition induces cell cycle arrest in diffuse large B cell lymphoma (DLBCL) cells and sensitises DLBCL cells to rituximab
Authors: Wanner Kathrin , Hipp Susanne , Oelsner Madlene , Ringshausen Ingo , Bogner Christian , Peschel Christian , Decker Thomas
Published: July 2006

Diffuse large B‐cell lymphoma (DLBCL) is a common lymphoma entity. Although a significant amount of DLBCL patients can be cured with modern chemotherapeutic regimens, a substantial proportion of patients die because of progressive disease. Therefore, new therapeutic strategies are clearly needed. Inhibitors of mTOR [mammalian target of rapamycin (Rap)] represent a new class of antiproliferative drugs with applications as immunosuppressive and anticancer agents. Extensive safety data exist on the mTOR inhibitor RAD001, which is already approved as an immunosuppressant in organ transplant recipients. Rap and RAD001 inhibited cell cycle progression in DLBCL cells by inducing a G1 arrest without inducing apoptosis. Phosphorylation of the main targets of mTOR, p70 s6 kinase and 4‐EBP‐1 was reduced in cells cultured in the presence of RAD001. Cell cycle arrest was accompanied by reduced phosphorylation of the retinoblastoma protein (RB) as well as reduced expression of cyclin D3 and A in all cell lines. Although the effect of the chemotherapeutic agent vincristine (vin) was not enhanced by RAD001, rituximab‐induced cytotoxicity was augmented in the rituximab‐sensitive cell lines. mTOR inhibition is a promising therapeutic strategy in DLBCL by inducing a G1 arrest and augments rituximab‐induced cytotoxicity. Therefore, combination of these drugs might be an interesting new therapeutic approach in DLBCL patients.
Testosterone and innate immune function inversely covary in a wild population of breeding Dark‐Eyed Juncos (Junco hyemalis)
Authors: GREIVES T. J. , MCGLOTHLIN J. W. , JAWOR J. M. , DEMAS G. E. , KETTERSON E. D.
Published: July 2006

Innate immunity refers to the non‐specific components of the primary immune response, which act broadly to destroy pathogens. Effective innate immune responses may save an individual the energetic costs associated with activating subsequent specific immune responses.

Testosterone can suppress immune function in vitro and in vivo. Most studies examining testosterone's effects on immunity have focused on experimentally elevated testosterone and acquired immune responses (e.g. humoral and cell‐mediated responses to foreign antigens). Few studies have investigated the relationship between endogenous levels of testosterone and innate immunity.

In a wild breeding population of Dark‐Eyed Juncos (Junco hyemalis Linnaeus), we asked whether endogenous levels of testosterone measured at several points during the breeding season covaried with two components of innate immunity: total levels of non‐specific immunoglobulin‐G (IgG), and complement levels.

Testosterone levels were significantly negatively correlated with both total IgG and complement activity. Both immune measures were also positively correlated with body mass. Taken together with experimental results from the same species, these results suggest that elevated testosterone levels may compromise innate as well as acquired immune function.
The phosphorylated C‐terminal domain of Xenopus Cut5 directly mediates ATR‐dependent activation of Chk1
Authors: Hashimoto Yoshitami , Tsujimura Tsuyoshi , Sugino Akio , Takisawa Haruhiko
Published: July 2006

ATR‐dependent activation of the kinase Chk1 is the initial step in signal transduction in the DNA replication checkpoint, which allows a cell to enter mitosis only after the completion of DNA replication. TopBP1‐related proteins in higher eukaryotes are implicated in the replication checkpoint, but their exact role remains elusive because of their requirements for replication initiation. Here we report that the initiation function of Xenopus Cut5/TopBP1 could be entirely separated from its checkpoint function: the N‐terminal half fragment, a region of Cut5 conserved through evolution, is sufficient for initiation, but is incapable of activating the checkpoint; the C‐terminal half fragment, which is unique in metazoan species, is by itself capable of activating the checkpoint response without initiating replication. Upon the activation of Chk1, the Ser1131 within the C‐terminal region of Cut5 is phosphorylated, and this phosphorylation is critical for the checkpoint response. Furthermore, Cut5 directly stimulated Chk1 phosphorylation in the in vitro kinase assay reconstituted with recombinant proteins and ATR immunoprecipitated from extracts. On the basis of replication protein A (RPA)‐dependent loading of Cut5 on to replicating and replication‐arrested chromatin, we propose that Cut5 plays a crucial role in the initial amplification step of the ATR‐Chk1 signaling pathway at the stalled replication fork.
Changes in soil carbon and nitrogen properties and microbial communities in relation to growth of Pinus radiata and Nothofagus fusca trees after 6 years at ambient and elevated atmospheric CO2
Authors: ROSS DES. J. , GRAYSTON SUSAN J. , WHITEHEAD DAVID
Published: July 2006

Increasing atmospheric CO2 concentration can influence the growth and chemical composition of many plant species, and thereby affect soil organic matter pools and nutrient fluxes. Here, we examine the effects of ambient (initially 362 μL L−1) and elevated (654 μL L−1) CO2 in open‐top chambers on the growth after 6 years of two temperate evergreen forest species: an exotic, Pinus radiata D. Don, and a native, Nothofagus fusca (Hook. F.) Oerst. (red beech). We also examine associated effects on selected carbon (C) and nitrogen (N) properties in litter and mineral soil, and on microbial properties in rhizosphere and hyphosphere soil. The soil was a weakly developed sand that had a low initial C concentration of about 1.0 g kg−1 at both 0–100 and 100–300 mm depths; in the N. fusca system, it was initially overlaid with about 50 mm of forest floor litter (predominantly FH material) taken from a Nothofagus forest. A slow‐release fertilizer was added during the early stages of plant growth; subsequent foliage analyses indicated that N was not limiting. After 6 years, stem diameters, foliage N concentrations and C/N ratios of both species were indistinguishable (P>0.10) in the two CO2 treatments. Although total C contents in mineral soil at 0–100 mm depth had increased significantly (P<0.001) after 6 years growth of P. radiata, averaging 80±0.20 g m−2 yr−1, they were not significantly influenced by elevated CO2. However, CO2‐C production in litter, and CO2‐C production, microbial C, and microbial C/N ratios in mineral soil (0–100 mm depth) under P. radiata were significantly higher under elevated than ambient CO2. CO2‐C production, microbial C, and numbers of bacteria (but not fungi) were also significantly higher under elevated CO2 in hyphosphere soil, but not in rhizosphere soil. Under N. fusca, some incorporation of the overlaid litter into the mineral soil had probably occurred; except for CO2‐C production and microbial C in hyphosphere soil, none of the biochemical properties or microbial counts increased significantly under elevated CO2. Net mineral‐N production, and generally the potential utilization of different substrates by microbial communities, were not significantly influenced by elevated CO2 under either tree species. Physiological profiles of the microbial communities did, however, differ significantly between rhizosphere and hyphosphere samples and between samples under P. radiata and N. fusca. Overall, results support the concept that a major effect on soil properties after prolonged exposure of trees to elevated CO2 is an increase in the amounts, and mineralization rate, of labile organic components.
Immobilized Glucose Isomerase Use in Mirin Production
Authors: TAKAYAMA TAKUMI , OYASHIKI HARUO , SAKAI TAKUO
Published: July 2006

The conversion of glucose in mirin (an alcoholic seasoning) to fructose using immobilized glucose isomerase (IGI) was studied in order to produce sweetened mirin without chill haze. The initial conversion velocity (Cm/tm) with IGI was affected by temperature, pH, and ethanol concentration. This reaction was first order, for which the temperature coefficient (Q10) over the range 20–55°C was 2.0. The value of Cm/tm was a maximum at pH 8.0, and decreased with an increase in ethanol. Conversions carried out in a continuous column reaction system had Cm/tm values 36 times higher than that in a batch system. Mirin treated with IGI did not form chill haze.
Soybean Flour Lipoxygenase Isozymes Effects on Wheat Flour Dough Rheological and Breadmaking Properties
Authors: CUMBEE B. , HILDEBRAND D.F. , ADDO K.
Published: July 2006

The effects of soy flour from LOX null mutant isolines and purified LOX isozymes on the rheological and breadmaking properties of a commercial hard wheat flour were investigated. Wheat flours were fortified with either 3% soy mutant flours alone, or in the presence of 0.2% and 1% linoleic acid. Purified LOX 2 isozyme had the greatest effect among LOX isozymes on dough extensibility and strength. Linoleic acid substrate addition reduced dough extensibility and strength. The L2L3 null isoline mutant for L1 resulted in the largest increase in bread volume. A reduction in bread firmness occurred after 5 day storage for all three single null mutant‐containing samples in the presence of 1.0% linoleic acid substrate.
Factors Affecting the Gelation Properties of Hydrolyzed Sunflower Proteins
Authors: SANCHEZ ANA C. , BURGOS JUSTINO
Published: July 2006

The effects of temperature and several chemicals on gelation time and strength of gels formed by heating (pH 8) 5% solutions of trypsin hydrolyzed sunflower proteins were studied by dynamic rheological methods. The storage modulus reached a maximum at 80°C. Ca2Cl (and NaCl at > 0.2M) accelerated gelation and weakened the gel. NaCOCH3Na2SO4 and NaSCN decreased the storage modulus. Urea decreased gelstrength and at high concentrations slowed gelation. Time for gelation diminished and gel strength increased with increasing mercaptoethanol concentration up to 0.1M. Propylene glycol at 5–20% concentrations accelerated gelation and at 5% also increased gel strength. Trypsin hydrolyzed sunflower proteins could be useful in products requiring strong gels at high temperatures.
Quality Assessment of Sardines During Storage by Measurement of Fluorescent Compounds
Authors: AUBOURG SANTIAGO P. , SOTELO CARMEN G. , GALLARDO JOSÉ M.
Published: July 2006

Sardine alterations during chilled storage (0°C) were investigated by measuring the fluorescence ratio between two excitation/emission maxima (393/463 nm, 327/415 nm) and compared with common quality indices. Sardines were also maintained at 15°C to accelerate all reactions occurring at 0°C. Other quality indices (total volatile base‐nitrogen, free fatty acids, formation of conjugated dienes, and thiobarbituric acid values) were determined and the use of the fluorescence ratio (fluorescence shift, δF) was analyzed. A high correlation was found between the δF and the total volatile base‐nitrogen (r = 0.93, at 0°C; r = 0.92, at 15°C).
Whey Improves Oxidative Stability of Soybean Oil
Authors: BROWDY A.A. , HARRIS N.D.
Published: July 2006

Whey powder and Maillard reaction products (MRP) produced from whey suppressed the formation of hydroperoxides and thiobarbituric acid‐reactive substances, and lowered oxygen uptake in the model system. The antioxidant activity of whey was dependent on concentration and preheating treatment. Unheated whey and whey heated for at 24 hr were most effective in retarding lipid oxidation. Whey solutions of 16% were most effective antioxidants followed by 10% and 3% solutions. As MRP indicators increased antioxidant activity increased. Whey may be useful as an antioxidant in some processed foods.
Kinetics of Casein Degradation during Ripening of Fynbo Cheese Salted with NaCl/KCl Brine
Authors: ZORRILLA SUSANA E. , RUBIOLO AMELIA C.
Published: July 2006

First‐order kinetics with respect to the αs1‐casein concentration was used to study casein degradation during low‐fat Fynbo cheese ripening. Effects of partial NaCl replacement by KCI during cheese salting were studied by statistical treatment of the casein degradation results. Four zones from cheeses at 1, 5, 10, 20, and 30 ripening days were analyzed by a polyacrylamide gel electrophoresis method. Similar kinetic parameters were obtained for a cheese salted with a NaCl/KCl brine and for a control cheese during ripening. Results were more affected by salt concentration than by salt substitution. KCl did not strongly influence kinetics of Fynbo cheese proteolysis.
Trisodium Phosphate Treatment of Pork Carcasses
Authors: MORRIS C.A. , LUCIA L.M. , SAVELL J.W. , ACUFF G.R.
Published: July 2006

Pork skin samples, naturally contaminated or inoculated with Salmonella typhimurium, were treated with varying levels of trisodium phosphate (TSP). Aerobic plate counts (APC) of the samples were unaffected by treatment; however, S. typhimurium was reduced (P < 0.05). Using levels most effective for reducing S. typhimurium on skin, TSP was investigated for use on whole pork carcasses during slaughter/processing and did not affect APC of pork carcasses. Due to a lack of detectable presence, any effects of TSP on native Salmonella contamination of pork carcass surfaces could not be determined. TSP had negligible effect on visual pork color, texture or odor.
Bacteriocins Applied to Food Packaging Materials to Inhibit Listeria monocytogenes on Meats
Authors: MING XINTAIN , WEBER GEORGE H. , AYRES JAMES W. , SANDINE WILLIAM E.
Published: July 2006

Bacteriocins in powders were produced from milk‐based media and applied to food packaging films. Nisin and pediocin “powders” were retained in casings during dialysis. Antilisterial casings were prepared by internal coating with pediocin. Antilisterial activity applied in powdered form was retained during processing and retained on contact food packaging surfaces. Pediocin powder was applied to plastic packaging bags at 7.75 μg/cm2. Meats and poultry samples were inoculated with Listeria monocytogenes. The bags coated with pediocin powder completely inhibited growth of inoculated L. monocytogenes through 12 wk storage at 4°C. Applying bacteriocins to food packaging films is an effective approach to reduce L. monocytogenes contamination in meats and poultry.
Red Wine and Model Wine Astringency as Affected by Malic and Lactic Acid
Authors: KALLITHRAKA S. , BAKKER J. , CLIFFORD M.N.
Published: July 2006

Red wines and model solutions containing grape seed phenols were assessed for perceived astringency, bitterness and sourness by a panel of trained assessors using time‐intensity (T–I) methodology. The effect of lactic and malic acid on perception of these attributes was evaluated at two pH values, by adding different amounts of acids. Maximum intensity (Imax) and total duration (Ttot) of astringency increased with decreasing pH in model solutions and red wine, but no differences were found between malic and lactic acid on perception of astringency. The pH and the acid type did not affect any of the bitterness T‐I parameters. However, sourness showed an increase in 1max and Ttot with decreasing pH.
Dried Soy Tofu Powder Effects on Frankfurters and Pork Sausage Patties
Authors: HO KAI‐LAI G. , WILSON LESTER A. , SEBRANEK JOSEPH G.
Published: July 2006

Regular frankfurters treated with tofu powder had decreased fat with no significant differences in color, texture, or overall acceptability compared to a control by sensory analysis. Lean frankfurters with tofu powder had lower moisture and color, better texture, and overall acceptability with no flavor differences from controls. Except for fracturability, there were no differences in texture‐related parameters by Texture Profile Analysis (TPA) between regular and control frankfurters but treated lean frankfurters had improved texture. Lean pork sausages treated with tofu powder were lower in fat, higher in protein, and moisture with no differences in sensory attributes compared to controls.
Enzymatic Browning Inhibition in Cloudy Apple Juice by Electrodialysis
Authors: TRONC JEAN‐SÉBASTIEN , LAMARCHE FRANÇOIS , MAKHLOUF JOSEPH
Published: July 2006

Cloudy apple juice (pH 3.8) was acidified to pH 2.7, at 16–24°C and at a constant current density of 40 mA/cm2, in an electrodialysis (ED) unit composed of an AB electrocell with three compartments, a bipolar membrane (Neosepta BP‐1) and two ion‐exchange membranes (anion‐ and cation‐exchange). The treatment inhibited 81% of the activity of polyphenoloxidase and slowed enzymatic browning, indicated by a decrease in indice “a” and an increase in “L” on the Hunter Lab colorimeter scale. During ED treatments, conductivity and K+ concentration in apple juice decreased by, respectively, 21% and 86%.
Analysis of Visual Quality Attributes of White Shrimp by Machine Vision
Authors: LUZURIAGA DIEGO A. , BALABAN MURAT O. , YERALAN SENCER
Published: July 2006

An important component of shrimp quality evaluation is determination of visual attributes by trained inspectors. This is subjective, time consuming, and difficult to quantify. An automated device was developed for repeatable, objective measurement of visual quality of shrimp. The device measured the count, uniformity ratio, color, melanosis, and detected foreign objects. Shrimp area viewed by a camera was used to estimate weight after calibration, and count and uniformity ratio was calculated. The system quantified color changes in white shrimp during iced storage. Melanosis was quantified and correlated with the grading of a trained inspector. The method objectively measured visual quality attributes of white shrimp in less than 1 min per sample.
Nutritional Value of Veal Bone Hydrolysate
Authors: LINDER MICHEL , ROZAN P. , EL KOSSORI R. LAMGHARI , FANNI J. , VILLAUME C. , MEJEAN L. , PARMENTIER M.
Published: July 2006

Industrial veal hydrolysate was produced enzymatically for possible use as a gelatin‐replacing ingredient for human consumption. Protein digestibility and nutritional value were determined in vitro and in vivo. Net protein ratio (= 2.65) and true digestibility (= 80.3) were compared with gelatin and caseinate. Protein digestibility was determined by pH‐stat method and cell dialysis. Amino acid composition including 4‐hydroxyproline, allowed determination of connective tissue, amino acid score and protein digestibility corrected amino acid score. High correlation was found between true digestibility and pH‐stat method (R2= 0.99). Meaty flavor and gelling properties of veal hydrolysate could make it useful for high‐quality soups, sauces and gravies.
Fat, Protein, and Mineral Components of Added Ingredients Affect Flavor Qualities of Tomato Soups
Authors: ROSETT TERRI R. , KENDREGAN SHERRY L. , KLEIN BARBARA P.
Published: July 2006

Ten tomato soups were prepared with deionized, distilled water, skim or whole milk, or deionized, distilled water with added fat (corn oil), protein (calcium caseinate), and/or minerals (NaCl, KCl, CaCl2) to equal the composition of whole milk. Tomato soups prepared with whole or skim milk were perceived as sweetest by a sensory panel of 12 trained subjects. Salt taste was probably masked by sweetness from lactose in milk. Added minerals may have increased saltiness either by adding to total Na+content or by freeing Na+from other ingredients making it more available for perception. Saltiness was suppressed by added protein, which increased pH, and may have affected Na+binding. Salt taste intensity correlated positively with tomato flavor.
Physicochemical Properties of Whey Protein‐Stabilized Emulsions as affected by Heating and Ionic Strength
Authors: DEMETRIADES K. , COUPLAND J.N. , McCLEMENTS D.J.
Published: July 2006

Corn oil‐in‐water emulsions (19.6 wt%; d32∼ 0.6 μm) stabilized by 2 wt% whey protein isolate (WPI) were prepared with a range of pH (3–7) and salt concentrations (0–100 mM NaCl). These emulsions were heated between 30 and 90°C and their particle size distribution, rheological properties and susceptibility to creaming measured. Emulsions had a paste‐like texture around the isoelectric point of WPI (∼φ 5) at all temperatures, but tended to remain fluid‐like at pH >6 or <4. Heating caused flocculation in pH 7 emulsions between 70 and 80°C (especially at high salt concentrations), but had little effect on pH 3 emulsions. Flocculation increased emulsion viscosity and creaming. Results were interpreted in terms of colloidal interactions between droplets.
Use of Ultrasound to Determine Cod Fillet Composition
Authors: GHAEDIAN REZA , DECKER ERIC ANDREW , McCLEMENTS DAVID JULIAN
Published: July 2006

The relationships between the composition and ultrasonic properties of Atlantic cod (Gadus morhua) fillets were examined. The lipid, protein, moisture and ash contents of cod fillets were determined by official methods. The ultrasonic velocity and attenuation coefficient of the fillets were measured using a pulse‐echo technique. The ultrasonic velocity of the fillets varied between 1575 and 1595 m s−1, decreasing linearly with increasing moisture content (r2 > 0.8 for 26 samples). No systematic relationship was observed between the attenuation coefficient and moisture content. Our experiments highlight the potential of using ultrasonic velocity measurements to rapidly and nondestructively determine the moisture content of cod fillets (and possibly their protein content by deduction).
Heat Inactivation Kinetics of Apple Polyphenoloxidase and Activation of its Latent Form
Authors: YEMENICIOĞLU AHMET , ÖZKAN MEHMET , CEMEROĞLU BEKIR
Published: July 2006

Heat inactivation kinetics of crude polyphenoloxidase (PPO) from six apple cultivars (Golden Delicious, Starking Delicious, Granny Smith; Gloster, Starcrimson and Amasya) were studied at three temperatures (68°, 73° and 78°C). PPO activity initially increased and then decreased with heat, following a first order kinetic model. Increase in activity indicated presence of latent PPO. Regression coefficients for the linear portions of inactivation curves were computed to determine inactivation parameters. Reaction data at 78°C revealed that PPO in Amasya was the least and Starking Delicious the most heat‐stable. Rate constants for heat inactivation at 78°C ranged from 15.99–28.27. 10−2 min−1. Activation energies varied between 54.7–77.2 kcal. mol−1 with z values of 7.1–10.0C°.PPO in apples was generally more heat‐stable than PPO in most fruits.
Hydrolysis of Milk Protein by a Bacillus licheniformis Protease Specific for Acidic Amino Acid Residues
Authors: MADSEN J.S. , QVIST K.B.
Published: July 2006

A serine protease, which preferentially cleaves peptide bonds at the carboxylic site of Glu and Asp was evaluated with milk proteins as substrate. The enzyme hydrolyzed casein almost 10 times more efficiently than whey protein. In the casein assay, whey protein did not inhibit the protease, but the enzyme activity in a chromogenic assay was severely inhibited by one whey protein, β‐lactoglobulin. Capillary electrophoresis of β‐lactoglobulin hydrolysate revealed a peptide profile corresponding to the numbers of susceptible bonds, The enzyme may provide advantages in preparation of functional protein fractions and in cheese ripening.