bluuebunny/crossref_metadata_2025 huggingface dataset:
Relaxor characteristics of Pb(Fe2∕3W1∕3)O3–BiFeO3 solid solution prepared by mechanosynthesis route
Authors: Choudhary R. N. P. , Pradhan Dillip K. , Tirado C. M. , Bonilla G. E. , Katiyar R. S.
Published: October 2006

The polycrystalline nanosize (∼60nm) of (1−x)Pb(Fe2∕3W1∕3)O3–x(BiFeO3) solid solutions with a wide range of concentrations (0⩽x⩽0.20) were fabricated using a mechanical activation followed by a conventional solid-state reaction technique. The formation of single-phase material and better solubility of two phases [i.e., BiFeO3 (BFO) and Pb(Fe2∕3W1∕3)O3 (PFW)] were confirmed using an x-ray diffraction technique. Studies of frequency and temperature dependences of dielectric parameters of solid solutions have provided unique relaxor characteristics of PFW on substitution of a critical composition (i.e., 10%) of BFO in it. The loss tangent (tanδ) peaks of PFW are frequency dependent above room temperature. The sharp tanδ peaks of PFW diffuse on increasing BFO content in PFW–BFO solid solution. This exhibits the induction of relaxation properties in the nonrelaxor PFW material. An ac conductivity (σac) of solid solutions is very much dependent on the frequency and temperature. The nature of temperature dependent conductivity and values of activation energies suggest that space charge and oxygen ion vacancies play an important role in the conduction mechanism in the material.
Brillouin spectrometer interfaced with synchrotron radiation for simultaneous x-ray density and acoustic velocity measurements
Authors: Sinogeikin Stanislav , Bass Jay , Prakapenka Vitali , Lakshtanov Dmitry , Shen Guoyin , Sanchez-Valle Carmen , Rivers Mark
Published: October 2006

We describe a new Brillouin spectrometer that has been installed on a synchrotron x-ray beamline for simultaneous measurements of sound velocities (by Brillouin scattering) and density (by x-ray diffraction). The spectrometer was installed at the 13-BM-D station (GSECARS) of the Advanced Photon Source. This unique facility has been tested in studies of transparent single crystal and polycrystalline materials at high pressure and temperature. The equation of state, acoustic velocities, and, hence, elastic moduli of materials as a function of pressure and temperature can now be determined without resort to a secondary pressure standard, such as the ruby fluorescence scale, or the equation of state of standard materials such as Au, Pt, or MgO, thus offering the potential to determine an absolute pressure scale. This article describes the design of the combined Brillouin-x-ray system and the first experimental results obtained. As a general-user facility, the system was designed to require minimal setup time and alignment of sensitive optics, run-time control and adjustments of optics from outside the experimental station, compatibility with powder and single crystal x-ray diffraction measurements, and no interference with other experimental techniques used on the beamline. To satisfy these requirements we adopted a novel optical design for the Brillouin system with a vertical scattering plane. Examples of measurements of acoustic velocities and elastic moduli on single crystal NaCl (B1) and polycrystalline NaCl (B2) at high pressure and single crystal velocities and elastic moduli of MgO at high temperature (to 600°C) and at high pressure are presented.
Development of battery powered 100kV dc power supply
Authors: Verma Rishi , Shyam A. , Nair Lakshmi
Published: October 2006

The increased interest in pulsed power field applications has generated the need for development of compact and remotely operated chargers driven by rechargeable batteries. With this objective, a compact and portable dc to dc Converter has been developed which has an output rating of 100kV, 0.4mA. The high voltage generation scheme uses a hybrid approach. The overall idea behind implementation of hybrid concept is to optimize voltage upliftment with suitable techniques for maximizing power delivered per unit volume. The proposed converter provides this feature and uses flyback converter in association with Cockcroft-Walton Multiplier [M. Jullian, Cockcroft-Walton Multiplier Optimum Design Guide V2.0, August 2005 (http//www.blazelabes.com)] for the generation of 100kV dc from 12V dc source, i.e., normal battery. In the first stage 12V dc is modulated/chopped into series of high frequency pulses by pulse width modulator and then increased in level up to 16kVpp by step up flyback transformer. Further by using n stage half wave series Cockcroft-Walton multiplier the voltage is stepped up to the level of 100kV. As switching device, state of the art metal-oxide-semiconductor field-effect transistor has been used. The obtained voltage multiplier cascade efficiency is 82.64%, whereas overall power conversion efficiency of the charging power supply is 85.47%. The control unit has been fiber optically isolated from high voltage unit due to safety consideration. The presented article explores complete design and development approach of compact and portable 100kV dc power supply which can be used for a variety of applications such as x-ray generation, ion implantation, charge particle acceleration, radio isotope production, etc.
One-photon photodetachment of I− in glycerol: Spectra and yield of solvated electrons in the temperature range 329⩽T⩽536K
Authors: Chandrasekhar N. , Krebs P. , Unterreiner A.-N.
Published: October 2006

Solvated electrons in glycerol were generated via a resonant one-photon photodetachment of the charge-transfer-to-solvent (CTTS) band of I− in glycerol (Gl) after irradiation with a 248nm excimer laser. Optical absorption spectra of solvated electrons (esolv−) in Gl were recorded as a function of temperature (381⩽T⩽505K). The observed redshift of the absorption maximum, ℏωmax, yields a temperature coefficient d(ℏωmax)∕dT=−(2.67±0.07)×10−3eVK−1. For solutions with a concentration c(I−)≈10−3M, the absorbance of esolv− at ℏωmax increases by a factor of about 65 when the temperature is raised from 329to536K. This effect can be partially explained by a temperature-dependent redshift of the CTTS spectrum of I− in Gl with respect to the laser wavelength. The main contribution to the increasing yield of esolv− is determined by diffusion controlled escape dynamics of the electron in the contact pair (I:e−)solv which is formed very fast during the detachment process. At room temperature no absorption of esolv− (absorbance<1.0×10−3) could be observed which is probably a result of an extremely small self-diffusion coefficient of Gl (a factor of 1250 lower than that of water at 298K). The results are compared with a previous study of I− in ethylene glycol.
Unsteady motion of two solid spheres in Stokes flow
Authors: Ardekani A. M. , Rangel R. H.
Published: October 2006

This study is concerned with the unsteady motion of two solid spherical particles in an unbounded incompressible Newtonian flow. The background flow is uniform and can be time dependent. In addition, the particle Reynolds numbers 2aVa∕ν and 2bVb∕ν, based on characteristic particles velocities Va and Vb, are assumed to remain small throughout the motion. Here, a and b denote the particle radii and ν is the kinematic viscosity of the fluid. Two approximate methods are employed in order to calculate the unsteady force exerted on each particle. In the first approach, a simplified method of reflections in combination with the point-force method is employed. In the second approach, a simplified method of reflections combined with Burger’s unsteady flow solution is considered. The forces due to the background flow and the disturbed flow created by the presence of particles are treated separately. The equation of motion for each particle is derived and some special cases are presented in detail including the motion with constant acceleration and the motion in a gravitational field. The results indicate that using the Basset force corresponding to the motion of two spheres gives rise to a larger drag force as compared to the solution utilizing the solitary-particle Basset force.
Distinguishability of N composition profiles in SiON films on Si by angle-resolved x-ray photoelectron spectroscopy
Authors: Powell C. J. , Werner W. S. M. , Smekal W.
Published: October 2006

Photoelectron intensities of N 1s and O 1s peaks at selected emission angles are reported for a SiON film on Si with different assumed amounts and distributions of N in the film. The intensities were determined from an efficient simulation tool for x-ray photoelectron spectroscopy (XPS) that incorporates appropriate values of elastic- and inelastic-scattering parameters in each region of the specimen as well as the finite angular acceptance of the analyzer. Appreciable dispersion of the intensities was found only for the N 1s peak at an emission angle of 75° (with respect to the surface normal). Conventional analyses of angle-resolved XPS data that include such large emission angles are unlikely to be valid due to angle-dependent changes of the attenuation length.
A density functional theory study of the dissociation of H2 on gold clusters: Importance of fluxionality and ensemble effects
Authors: Barrio L. , Liu P. , Rodríguez J. A. , Campos-Martín J. M. , Fierro J. L. G.
Published: October 2006

Density functional theory was employed to calculate the adsorption/dissociation of H2 on gold surfaces, Au(111) and Au(100), and on gold particles from 0.7 (Au14) to 1.2nm (Au29). Flat surfaces of the bulk metal were not active towards H2, but a different effect was observed in gold nanoclusters, where the hydrogen was adsorbed through a dissociative pathway. Several parameters such as the coordination of the Au atoms, ensemble effects and fluxionality of the particle were analyzed to explain the observed activity. The effect of the employed functional was also studied. The flexibility of the structure, i.e., its adaptability towards the adsorbate, plays a key role in the bonding and dissociation of H2. The interaction with hydrogen leads to drastic changes in the structure of the Au nanoparticles. Furthermore, it appears that not only low coordinated Au atoms are needed because H2 adsorption/dissociation was only observed when a cooperation between several (4) active Au atoms was allowed.
Depth-resolved residual strain in MoN∕Mo nanocrystalline films
Authors: Chen Gang , Singh Dileep , Eryilmaz Osman , Routbort Jules , Larson Bennett C. , Liu Wenjun
Published: October 2006

The authors have applied cross-sectional x-ray microdiffraction to measure depth-resolved in-plane residual strain in nanocrystalline MoN∕Mo bilayer films deposited on Si. Compressive strains with large gradients were found in the as-deposited films. After thermal annealing, the strain profiles and diffraction peak widths of the MoN and Mo layers were altered. These findings provide insights on the relationship between defects introduced during film processing and the effect of annealing on the structure and properties of magnetron-sputtered nanocrystalline films.
Femtosecond nonlinear optical properties of tellurite glasses
Authors: Souza Rogério F. , Alencar Márcio A. R. C. , Hickmann Jandir M. , Kobayashi Renata , Kassab Luciana R. P.
Published: October 2006

The third-order nonlinear optical properties of tellurite glasses with different compositions were investigated in the femtosecond regime at 810nm. Using the I-scan technique, positive nonlinear refractive indices of ∼10−15cm2∕W were measured. The authors also determined that nonlinear absorption was negligible for all studied samples. This result, added to their good chemical stability, indicates that tellurite glasses are promising materials for ultrafast photonic applications.
Simulation of shock-induced plasticity including homogeneous and heterogeneous dislocation nucleations
Authors: Shehadeh Mutasem A. , Bringa E. M. , Zbib H. M. , McNaney J. M. , Remington B. A.
Published: October 2006

A model of plasticity that couples discrete dislocation dynamics and finite element analysis is used to investigate shock-induced dislocation nucleation in copper single crystals. Homogeneous nucleation of dislocations is included based on large-scale atomistic shock simulations. The resulting prodigious rate of dislocation production takes the uniaxialy compressed material to a hydrostatically compressed state after a few tens of picoseconds. The density of dislocations produced in a sample with preexisting dislocation sources decreases slightly as shock rise time increases, implying that relatively lower densities would be expected for isentropic loading using extremely long rise times as suggested experimentally.
Two-photon pumped random laser in nanocrystalline ZnO
Authors: Chelnokov E. V. , Bityurin N. , Ozerov I. , Marine W.
Published: October 2006

Thin film of ZnO nanoparticles with dimension of about 5–10nm were fabricated by the pulsed laser ablation method. By using a femtosecond laser beam at 700nm to pump micrometer-thick films the authors observed two-photon-induced lasing at 385nm. Experimentally obtained dependence of the threshold on the excitation spot radius r0 is closer to (1∕r02) than to (1∕r0), thus suggesting efficiency of the feedback by scattering-random lasing. The experimental data on nonlinear transmission of the film at the wavelength of pumping are presented.
Characteristics of 1.3μm quantum-dot lasers with high-density and high-uniformity quantum dots
Authors: Amano Takeru , Sugaya Takeyoshi , Komori Kazuhiro
Published: October 2006

The authors realized a five-layered 1.3μm InAs quantum dot (QD) with a high density and uniformity of 8.0×1010cm−2/sheet and 23meV, respectively, by employing an As2 source and a gradient-composition strain reducing layer. Further, the authors demonstrated the 1.3μm wavelength emission of this five-layered QD laser with a 0.5mm cavity length and cleaved facet at room temperature. Moreover, the authors could achieve a high modal gain of 43cm−1 at 1.3μm because of the high density and uniformity of the QDs.
Differences in survival and neonatal metabolism in lambs from flocks selected for or against staple strength
Authors: Thompson M. J. , Briegel J. R. , Thompson A. N. , Adams N. R.
Published: October 2006

In the field, we found that lamb mortality was lower (P < 0.01) in a flock selected for wool staple strength (SS+) than in a flock selected against staple strength (SS–), or a random-bred control flock (R); mortality rates calculated from 4200 records were 17.0, 22.8, and 24.1%, respectively. The proportion of twins was similar in all flocks, but birth weights differed (P < 0.01), being 4.40, 4.25, and 4.14 kg, respectively. Biochemical profiles were measured in lambs from 20 ewes from each flock around the time of birth in an animal-house study, to define potential causes of the genetic difference in survival. In the intensive study, birth weight was similar for all groups; however, gestation length was slightly shorter in the SS+ lambs (P < 0.05 for SS+ v. R). All lambs had low plasma concentrations of the essential amino acids and glucose at birth, compared with after suckling. Plasma concentrations of glucose, non-esterified fatty acids (NEFA), and blood urea nitrogen (BUN) at birth differed between lambs from the flocks with the greatest difference in mortality (i.e. SS+ v. R); that is, SS+ lambs had higher concentrations of glucose (1.84 v. 1.23 mm; P < 0.01) and NEFA (1.52 v. 1.08 mm; P < 0.05), and lower concentrations of BUN (7.7 v. 9.7 mm; P < 0.01) at birth, and for the next 9 h. The semimembranosus and semitendinosus muscle of the SS+ lambs also had lower concentrations of ATP (7.4 v. 5.0 μmol/g, respectively) compared with lambs from the other flocks, immediately post-partum. Muscle phosphocreatinine was also slightly lower in the SS+ lambs. No differences between the genotypes were observed in reserves of glycogen, carcass fat, brown adipose tissue, or in neonatal thyroid hormones. In summary, sheep selected for high wool staple strength had lower lamb mortality than the other 2 flocks. This was accompanied by metabolic differences at birth that can be associated with greater metabolic maturity, rather than greater energy reserves.
Botrytis grey mould of chickpea: a review of biology, epidemiology, and disease management
Authors: Pande S. , Galloway J. , Gaur P. M. , Siddique K. H. M. , Tripathi H. S. , Taylor P. , MacLeod M. W. J. , Basandrai A. K. , Bakr A. , Joshi S. , Kishore G. Krishna , Isenegger D. A. , Rao J. Narayana , Sharma M.
Published: October 2006

Botrytis grey mould (BGM), caused by Botrytis cinerea Pers. ex. Fr., is an economically important disease of chickpea (Cicer arietinum L.), especially in areas where cool, cloudy, and humid weather persists. Several epidemics of BGM causing complete crop loss in the major chickpea-producing countries have been reported. The pathogen B. cinerea mainly survives between seasons on infected crop debris and seeds. Despite extensive investigations on pathological, physiological, and molecular characteristics of B. cinerea causing grey mould type diseases on chickpea and several other hosts, the nature of infection processes and genetic basis of pathogen variability have not been clearly established. This lack of information coupled with the need for repeated application of chemical fungicides forced the deployment of host plant resistance (HPR) as a major option for BGM management. Effective and repeatable controlled-environment and field-screening techniques have been developed for identification of HPR. Of the selected portion of chickpea germplasm evaluated for BGM resistance, only few accessions belonging to both cultivated and wild Cicer spp. were tolerant to BGM, and the search for higher levels of disease resistance continues. Fungicide application based on disease predictive models is helpful in precision-based fungicide application. Integrated disease management (IDM) of BGM has proved more effective than any of the individual disease management components in large-scale, on-farm studies conducted in India, Nepal, and Bangladesh. Further information on the biology of B. cinerea and epidemiology of the disease is needed to strengthen the IDM programs. In this paper the biology of B. cinerea including its variability, epidemiology of BGM, identified sources of resistance, and other management options, and available information on biochemical and genetic basis of disease resistance have been reviewed with a mention of future research priorities.
Fibrosis, not cell size, delineates β-myosin heavy chain reexpression during cardiac hypertrophy and normal aging
in vivo
Authors: Pandya Kumar , Kim Hyung-Suk , Smithies Oliver
Published: October 2006

Reexpression of the fetally expressed β-myosin heavy chain (β-MHC) gene is a well documented marker of pathological cardiac hypertrophy and normal aging in many experimental models. To gain insights into factors affecting this reexpression of β-MHC within the complex anatomical structure of the heart, we investigated the spatial pattern of its expression at the level of single cells during aging and hypertrophy. We generated mice that express yellow fluorescent protein fused to the N terminus of the β-MHC and examined its expression pattern during normal aging and in mice with hypertrophy induced by constitutive expression of a renin transgene. The localization of fibrosis within the hearts also was determined by using a fluorescent lectin. The results show that reexpression of β-MHC occurs in discrete subsets of myocytes within the subendocardium rather than uniformly throughout the heart, that β-MHC induction is not an obligatory consequence of cellular hypertrophy, and that β-MHC-expressing cells in the normal aging heart and the hypertrophic heart are distributed predominantly in clusters within and surrounding foci of fibrosis. We conclude that β-MHC gene expression in the normal aging adult and hypertrophic mouse heart is a marker of fibrosis rather than of cellular hypertrophy.
Commonly Studied Single-Nucleotide Polymorphisms and Breast Cancer: Results From the Breast Cancer Association Consortium
Authors:   The Breast Cancer Association Consortium
Published: October 2006

Background: The Breast Cancer Association Consortium (BCAC) is an international collaboration that was established to provide large sample sizes for examining genetic associations. We conducted combined analyses on all single-nucleotide polymorphisms (SNPs) whose associations with breast cancer have been investigated by at least three participating groups. Methods: Data from up to 12 studies were pooled for each SNP ( ADH1C I350V, AURKA F31I, BRCA2 N372H, CASP8 D302H, ERCC2 D312N, IGFBP3 −202 c > a , LIG4 D501D, PGR V660L, SOD2 V16A, TGFB1 L10P, TP53 R72P, XRCC1 R399Q, XRCC2 R188H, XRCC3 T241M, XRCC3 5′ UTR, and XRCC3 IVS7-14). Genotype frequencies in case and control subjects were compared, and genotype-specific odds ratios for the risk of breast cancer in heterozygotes and homozygotes for the rare allele compared with homozygotes for the common allele were estimated with logistic regression. Statistical tests were two-sided. Results: The total number of subjects for analysis of each SNP ranged from 12 013 to 31 595. For five SNPs— CASP8 D302H, IGFBP3 −202 c > a , PGR V660L, SOD2 V16A, and TGFB1 L10P—the associations with breast cancer were of borderline statistical significance ( P = .016, .060, .047, .056, and .0088 respectively). The remaining 11 SNPs were not associated with breast cancer risk; genotype-specific odds ratios were close to unity. There was some evidence for between-study heterogeneity ( P <.05) for four of the 11 SNPs ( ADH1C I350V, ERCC2 D312N, XRCC1 R399Q, and XRCC3 IVS5-14). Conclusion: Pooling data within a large consortium has helped to clarify associations of SNPs with breast cancer. In the future, consortia such as the BCAC will be important in the analysis of rare polymorphisms and gene × gene or gene × environment interactions, for which individual studies have low power to identify associations, and in the validation of associations identified from genome-wide association studies.
Eosinophilic cellulitis presented with semicircular pattern
Authors: KARABUDAK Ozlem , DOGAN Bilal , TASKAPAN Oktey , HARMANYERI Yavus
Published: October 2006

Eosinophilic cellulitis (Wells’ syndrome) is a rare condition of unknown etiology and pathogenesis. It is characterized by erythematous plaques and a histological picture of dermal eosinophilic infiltration with “flame figures”. The typical clinical presentation of eosinophilic cellulitis is mildly pruritic cellulite‐like plaques. Urticarial, vesiculo‐bullous, nodular and papulonodular variants were also reported. Herein, we describe a patient with annular and semicircular manifestations of eosinophilic cellulitis. It was treated successfully with low‐dose cyclosporine A treatment.
Effects of skin care and makeup under instructions from dermatologists on the quality of life of female patients with acne vulgaris
Authors: MATSUOKA Yoshie , YONEDA Kozo , SADAHIRA Chieko , KATSUURA Junko , MORIUE Tetsuya , KUBOTA Yasuo
Published: October 2006

Acne vulgaris significantly affects patients’ quality of life (QOL) and their lives in various ways, including social behavior and body dissatisfaction. This may be heightened by acne's typical involvement of the face. We investigated whether the use of skin care and makeup could influence the QOL of affected patients without deteriorating conventional acne treatments. Fifty female patients with acne were recruited for our study. Twenty‐five patients were instructed how to use skin care and cosmetics, while 25 patients received no specific instructions from dermatologists. Both groups received conventional topical and/or oral medication for acne during the study period for 4 weeks. Both groups did not show any significant difference in clinical improvement of acne severity. Two validated QOL questionnaires, World Health Organization (WHO)QOL26 and the Dermatology Life Quality Index (DLQI) were administered to all patients at first visit and 4 weeks later. The mean scores of psychological and overall domains in WHOQOL26 for patients with instructions were improved significantly, while only the overall score was significantly improved for patients without instructions. The total mean scores and all domains except work/school in DLQI for patients with instructions were improved significantly, while the total scores and all domains except discomfort for treatment in DLQI were significantly improved for patients without instructions. Thus, instructions on the use of skin care and cosmetics for female acne patients did not deteriorate acne treatment and influenced patients’ QOL effectively. We therefore suggest that instructions for using skin care and cosmetics complement conventional medical treatments for acne.
Combination of pulse therapy with terbinafine tablets and topical terbinafine cream for the treatment of dermatophyte onychomycosis: A pilot study
Authors: NAKANO Naomi , HIRUMA Masataro , SHIRAKI Yumi , CHEN Xuejun , PORGPERMDEE Sarawan , IKEDA Shigaku
Published: October 2006

We performed a pilot study to assess the safety and efficacy of pulse therapy with terbinafine tablets in 66 patients with dermatophyte onychomycosis. One pulse consisted of oral terbinafine tablets (500 mg/day) given for 1 week followed by a 3‐week interval. Topical 1% terbinafine cream was applied daily. The number of pulses was determined by the extent of improvement in the affected nails and by the patient's requests, up to a maximum of six pulses. Efficacy was assessed based on both clinical and mycological examinations 1 year after treatment initiation. We observed a complete cure in 51 patients (77.3%), marked improvement in five patients (7.6%), improvement in five patients (7.6%) and slight improvement in one patient (1.5%). Four patients (6.0%) showed no change. In the patients who were completely cured, the average number of pulses used was 3.7 ± 1.4 pulses and the treatment duration was 3.3 ± 1.6 months. Nine patients experienced adverse effects, consisting of gastrointestinal disturbance (eight patients) and drug‐induced eruption (one patient). There were no abnormal findings in the laboratory tests, including liver function tests. In summary, terbinafine pulse therapy in combination with topical application of terbinafine cream appeared safe and effective in this pilot study.
Review article: interactions between genotype and response to therapy in inflammatory bowel diseases
Authors: HERRLINGER K. R. , JEWELL D. P.
Published: October 2006

Background

More than half of the patients with inflammatory bowel diseases are candidates for immunosuppressive therapy. However, even the most effective drugs used in inflammatory bowel disease are only successful in about two‐thirds of patients. Adverse events limit their use in a further substantial proportion of patients. Recent research has focussed on the possibility of predicting a drugs’ efficacy and/or toxicity by identifying polymorphic variants in the genes encoding enzymes involved in metabolic pathways.

Aim

To highlight recent advances and limitations in the field of pharmacogenetics in inflammatory bowel disease.

Results

Recent pharmacogenetic studies have mainly focussed on immunosuppressive agents including corticosteroids, azathioprine, methotrexate and infliximab. Several polymorphic genes encoding enzymes involved in the metabolism of these drugs have been identified including the inosine triphosphate pyrophosphatase in thiopurine therapy, the methylene tetrahydrofolate reductase in methotrexate therapy and polymorphisms in apoptosis genes in infliximab therapy. However, at the present time, genotyping for the variants of the thiopurine methyltransferase gene, an enzyme important for the metabolism of the thiopurine drugs, is the only useful test in clinical practice.

Conclusions

Although the field of pharmacogenetics in inflammatory bowel disease is promising most new targets have so far failed to translate into clinical practice. Future pharmaceutical trials should include pharmacogenetic research to test appropriate candidate genes in a prospective manner.
Persistence and recolonisation determine success of bog restoration for aquatic invertebrates: a comment on Mazerolle et al. (2006)
Authors: VAN DUINEN G. A. , VERBERK W. C. E. P. , ESSELINK H.
Published: October 2006

1. Mazerolle et al. (2006) concluded that some aquatic invertebrate species, including bog‐associated species, readily colonise man‐made bog pools. In contrast, in Dutch bog remnants Van Duinen et al. (2003) found that a considerable number of bog‐associated species do not colonise newly created bog pools.

2. The conclusion of Mazerolle et al. (2006) is based on vagile aquatic invertebrates. Here, we question whether their conclusion can be extended to more sedentary species, which were not captured in the Canadian study, but made up an important part of the invertebrate assemblage in the Dutch study. This discrepancy could be caused by sampling artefacts, low colonisation rates of these species or an incomplete restoration of site conditions.

3. In Canada, chances of recolonisation may be higher than in the Netherlands, as natural and near‐natural bogs are more extensive. In the Netherlands, with low chances of recolonisation, persistence of species may be more important. To disentangle the relative importance of persistence and recolonisation, evaluations of the success of restoration projects need to cover the entire invertebrate assemblage, including both vagile and more sedentary species.
Carbohydrate metabolism genes and pathways in insects: insights from the honey bee genome
Authors: Kunieda T. , Fujiyuki T. , Kucharski R. , Foret S. , Ament S. A. , Toth A. L. , Ohashi K. , Takeuchi H. , Kamikouchi A. , Kage E. , Morioka M. , Beye M. , Kubo T. , Robinson G. E. , Maleszka R.
Published: October 2006

Carbohydrate‐metabolizing enzymes may have particularly interesting roles in the honey bee, Apis mellifera, because this social insect has an extremely carbohydrate‐rich diet, and nutrition plays important roles in caste determination and socially mediated behavioural plasticity. We annotated a total of 174 genes encoding carbohydrate‐metabolizing enzymes and 28 genes encoding lipid‐metabolizing enzymes, based on orthology to their counterparts in the fly, Drosophila melanogaster, and the mosquito, Anopheles gambiae. We found that the number of genes for carbohydrate metabolism appears to be more evolutionarily labile than for lipid metabolism. In particular, we identified striking changes in gene number or genomic organization for genes encoding glycolytic enzymes, cellulase, glucose oxidase and glucose dehydrogenases, glucose‐methanol‐choline (GMC) oxidoreductases, fucosyltransferases, and lysozymes.
Image Segmentation and Bruise Identification on Potatoes Using a Kohonen's Self‐Organizing Map
Authors: Marique Thierry , Pennincx Stephanie , Kharoubi Ammar
Published: October 2006

Potato quality includes a low incidence of colored bruises resulting from bad storage or manipulation practices. We developed a procedure to process and segment potato images by using Kohonen's self‐organizing map. Anomalous regions could be distinguished on 3 potato varieties. Bruises that were very dissimilar in appearance were correctly identified, and some particular defects such as green spots could be located as well.
Evaluation of High Pressure Processing as an Additional Hurdle to Control Listeria monocytogenes and Salmonella enterica in Low‐Acid Fermented Sausages
Authors: Marcos Begonya , Aymerich Teresa , Garriga Margarita
Published: October 2006

Low‐acid fermented sausages (fuet and chorizo) were manufactured to evaluate the combined effect of high pressure processing (HPP) and ripening on foodborne pathogens. Raw sausages inoculated with a three‐strain cocktail of Salmonella ser. Derby, London, and Schwarzengrund, and a three‐strain cocktail of L. monocytogenes ser. 1/2 c and 4b were pressurized at 300 MPa for 10 min at 17 °C. Afterwards, sausages were ripened at 12 °C and 80% RH for 27 d. Salmonella counts decreased in all studied sausages during ripening. However, the application of HPP as an additional hurdle to the ripening process produced a greater decrease in the Salmonella population, showing lower counts (3 MPN/g) in ripened sausages. By contrast, lower values of L. monocytogenes counts were obtained in non‐treated (NT) than in pressurized sausages due to the delay of pH drop caused by HPP inactivation of endogenous lactic acid bacteria. After pressurization of raw sausages at 300 MPa, a discoloration of sausages was observed, coinciding with an increase in L* values.
Effect of Water Activity on Thermal Inactivation of Salmonella in Ground Turkey
Authors: Carlson Tausha R. , Marks Bradley P. , Booren Alden M. , Ryser Elliot T. , Orta‐Ramirez Alicia
Published: October 2006

Many factors, such as fat content and pH, are known to affect thermal inactivation of pathogens in meat products, and a few studies have suggested that the humidity of the cooking environment also affects thermal inactivation. However, the effect of process humidity has not been previously isolated from the effect of water activity on Salmonella inactivation. Therefore, the objective of this study was to directly test the effect of meat water activity on thermal inactivation of Salmonella. Ground turkey was dried to achieve water activities of 0.95 to 0.99, inoculated with an 8‐strain Salmonella cocktail, and heated isothermally (60 °C) in a water bath. The rate of thermal inactivation of Salmonella decreased 64% (P < 0.01) when decreasing meat water activity from 0.99 to 0.95. Inclusion of water activity improved the accuracy of a 1st‐order/Arrhenius‐type inactivation model from 1.94 log10 to 0.8 log10 (colony‐forming units [CFU]/g).
Sporulation and Heat Resistance of Spores from a Clostridium sp. RKD
Authors: Dixit Aparna , Alam Syed Imteyaz , Dhaked Ram Kumar , Singh Lokendra
Published: October 2006

A Clostridium sp. RKD isolated from the intestine of decaying fish, showing 99% sequence identity with Clostridium tetani at a 16S rRNA level, produced a neurotoxin that was neutralized by botulinum antitoxin (A+B+E). It also showed an amplification of near‐expected size when polymerase chain reaction (PCR) was performed using group‐ and type‐specific primers for botulinum neurotoxin type B. The isolate exhibited differences with both C. tetani and Clostridium botulinum with respect to phenotypic characteristics and chemotaxo‐nomic markers. Spore production was optimized with respect to media composition and stage of growth. Time‐dependant examination of sporulation revealed 2.6% to 49.0% spores in the late stationary phase culture when grown in different broth media. A simpler method for spore production and isolation from culture grown in tryptose sulfite cycloserine (TSC)/anaerobic agar sandwich resulted in >95% sporulation, which could be purified to near homogeneity by a simple 2‐step procedure. Thermal resistance of spores revealed a biphasic inactivation at lower temperatures with D values for linear inactivation varying from 26.6, 8.0, and 4.3 min at 70 °C, 80 °C, and 90 °C, respectively. The z values of 7.86 °C and 10.47 °C were obtained in the linear and tail regions, respectively. The Weibull parameter b values at 70 °C, 80 °C, and 90 °C were 27.38, 3.55, and 0.99, respectively, with a z’ value of 13.869 °C. The shape parameter n at 70 °C, 80 °C, and 90 °C were 0.63, 0.55, 0.45, respectively. Spores produced on 2 different media (cooked meat medium [CMM] and trypticase peptone yeast‐extract glucose [TPYG] agar) exhibited differences in heat resistance. The addition of lysozyme (50 jj.g/mL) before heat treatment resulted in increased thermal resistance of spores.
Umami Taste Enhancement of MSG/NaCl Mixtures by Subthreshold L‐α‐Aromatic Amino Acids
Authors: Lioe Hanifah N. , Apriyantono Anton , Takara Kensaku , Wada Koji , Yasuda Masaaki
Published: October 2006

l‐Phenylalanine (l‐Phe) and l‐tyrosine (l‐Tyr) are L‐α‐aromatic amino acids that have recently been discovered to be important components of the savory fractions of soy sauce in addition to l‐glutamate. Their effects are evaluated on the umami or savory taste of monosodium L‐glutamate (MSG), with or without sodium chloride (NaCl). Because l‐Phe at subthreshold concentration (1.0 mM) significantly enhances an umami taste of a MSG/NaCl mixture (P= 0.000), combinations of 4 subthreshold concentrations (0, 0.5, 1.5, and 5.0 mM) of l‐Phe with a weakly suprathreshold MSG (4.0 mM) and NaCl (80 mM) mixture were then rated for salty and umami intensities relative to those of standard solutions. L‐Phe was found to significantly enhance the umami tastes of the MSG/NaCl mixtures when it was added in a concentration range of 0.5 to 5.0 mM (P= 0.000). However, neither the umami taste of MSG alone nor the salty taste of NaCl alone was intensified. In a further experiment, l‐Tyr at the 3 subthreshold concentrations (0, 0.5, and 1.5 mM) studied was shown to have the same activity as L‐Phe. The phenomenon of umami or savory enhancement by subthreshold aromatic amino acids in the soy sauce system has been established.
Sensory Evaluation of Butterfat‐Vegetable Oil Blend Spread Prepared with Structured Lipid Containing Canola Oil and Caprylic Acid
Authors: Kim Byung Hee , Shewfelt Robert L. , Lee Hyoungil , Akoh Casimir C.
Published: October 2006

Structured lipid (SL) was synthesized from canola oil and caprylic acid with sn‐1,3 specific lipase from Rhizomucor miehei. Cold‐spreadable butter was made by blending butterfat with the SL at a weight ratio of 80:20. Its sensory attributes were compared with pure butter and butterfat‐canola oil 80:20 blend spread by headspace solid‐phase microextraction (SPME) procedure and sensory analyses (descriptive analysis and triangle test) to determine the effect of the SL on the sensory profiles of the spread. Butterfat‐SL blend had significantly (P < 0.05) lower contents of hypercholesterolemic fatty acids (FAs) and the lowest atherogenic index (AI) compared with the others. In the volatile compounds analysis, free caprylic acid was detected in the butterfat‐SL blend spread only. Descriptive analysis results indicated that butterfat‐SL blend spread was significantly (P < 0.05) more cold‐spreadable than pure butter, whereas its overall textural profile was very similar to that of butterfat‐canola oil blend spread. However, no significant (P < 0.05) differences were found between all the spread samples in the flavor attributes including caprylic acid flavor. Triangle test results also showed that significant (P < 0.001) difference was found in cold‐spreadability between pure butter and butterfat‐SL blend spread, but there was no significant (P < 0.05) difference between butterfat‐canola oil blend spread and butterfat‐SL blend spread. Our results indicate that SL can counterbalance the hypercholester‐olemic attributes of butterfat as well as improve the cold‐spreadability of the experimental spread without any adverse effect on the flavor attributes of the spread.
Composition and Structure of Fat Bloom in Untempered Chocolate
Authors: Kinta Yasuyoshi , Hatta Tamao
Published: October 2006

It is generally accepted that visual fat bloom is caused by the separation of cocoa butter toward the surface. However, this is not always true for all types of bloom. One type of fat bloom, which can occur due to lack of tempering, has still not been completely elucidated. We performed a compositional and structural study of this type of fat bloom in plain chocolate. More specifically, we performed (1) an investigation of its crystallographic properties, (2) investigation of fat content, (3) analysis of the composition of triacylglycerol (TAG), (4) stereomicroscopic observations, and (5) observation and elemental analysis using a scanning electron microscope with an energy‐dispersive X‐ray spectrometer (SEM‐EDS). In the bloomed chocolate, the fat content in the light brown phase was lower than that in the black phase. Concerning fat composition, the content of sn‐1,3‐saturated acyl, sn‐2‐oleoyl glycerols (Sat‐O‐Sat type TAGs) in the light brown phase was lower. The lower fat content is thought to result in its lighter color. The results of our composition analysis and morphological observations suggest that the mechanism of the bloom generation due to nontempering involves not the separation of fat toward the surface but the crystallization of fat which leads to withdrawal of fat from the vicinity of the growing crystal, leading to differences in fat content.
Effects of Long‐term Storage on Sensory and Nutritional Quality of Rolled Oats
Authors: McEwan Michael , Ogden Lynn V. , Pike Oscar A.
Published: October 2006

Sixteen samples of regular and quick‐cooking rolled oats stored up to 28 y in a reduced oxygen atmosphere in nr 10 cans at ambient temperatures were analyzed for sensory and nutritional quality. A consumer panel evaluated aroma, texture, flavor, aftertaste, and overall acceptability using a 9‐point hedonic scale. Hedonic scores varied from 4.8 to 6.7. Although there was a loss of sensory quality in samples over time, all samples were considered acceptable by at least 3/4 of panelists for use in an emergency. Vitamin B1 amounts ranged from 2.7 to 6.6 μg/g and were highest in some older samples. Vitamin E amounts ranged from 1.3 to 37.8 μg/g and were negatively correlated with headspace hexanal levels. Rolled oats can be included in long‐term food storage regimens because of their sensory and nutritional stability when properly packaged and stored.
Quality Changes of Shrimp (Pandalus borealis) Stored under Different Cooling Conditions
Authors: Zeng Qing Zhu , Thorarinsdottir Kristin A. , Olafsdottir Gudrun
Published: October 2006

The influence of different cooling techniques and storage temperatures (‐1.5 °C or 1.5 °C) to prolong the shelf life of shrimp was evaluated by sensory analysis, physical methods, chemical analysis, and microbial analysis. Storage in liquid ice was more effective than flake ice or brine mixed with flake ice in delaying spoilage of the shrimp by slowing down microbial growth and formation of total volatile basic nitrogen (TVB‐N) and trimethylamine (TMA). Total viable counts (TVC) showed that bacteria grew most quickly in shrimp stored in flake ice and in brine mixed with flake ice, followed by those in liquid ice at 1.5 °C and ‐1.5 °C, respectively. Lowest counts were observed in shrimp stored in liquid ice at ‐1.5 °C where the lag phase of growth was apparently extended at the beginning of storage. Principal component analysis (PCA) showed a good correlation between quality indicators related to microbial growth, TVC, pH, TVB‐N, TMA, responses of an electronic nose and sensory evaluation.
Cloning and nucleotide sequence analysis of the serotype 2 fimbrial subunit gene of Bordetella pertussis
Authors: Livey I. , Duggleby C.J. , Robinson A.
Published: October 2006

An oligonucleotide probe complementary to the beginning of the gene encoding the serotype 2 (ST2) fimbrlal subunit of Bordetella pertussis was synthesized and a cloned DNA fragment hybridizing with the probe identified and sequenced. Several lines of evidence indicate that an open reading frame with coding Information for a polypeptide of 207 amino acids, including a 26‐amino‐acid signal sequence, is the ST2 gene. The protein deduced from the nucleotide sequence shows good agreement with the NH2‐terminal amino acid sequence, amino acid composition and molecular weight of the purified fimbrial subunit. In addition, the proposed ST2 subunit is shown to have homology with other fimbrial subunits.
Reassortment of DNA recognition domains and the evolution of new specificities
Authors: Gann A. A. F. , Campbell A. J. B. , Collins J. F. , Coulson A. F. W. , Murray N. E.
Published: October 2006

Type I restriction enzymes comprise three subunits only one of which, the S polypeptide, dictates the specificity of the DNA sequence recognized. Recombination between two different hsdS genes, SP and SB, led to the isolation of a system, SQ, which had a different specificity from that of either parent. The finding that the nucleotide sequence recognized by SQ is a hybrid containing components from both the SP and SB target sequences suggested that DNA recognition is carried out by two separable domains within each specificity polypeptide. To test this we have made the recombinant gene of reciprocal structure and demonstrate that it encodes a polypeptide whose recognition sequence, deduced In vivo, is as predicted by this model. We also report the sequence of the SB specificity gene, so that information is now available for the five known members of this family of enzymes. Ali show a similar organization of conserved and variable regions. Comparisons of the predicted amino acid sequences reveal large non‐conserved areas which may not even be structurally similar. This is remarkable since these different S subunits are functionally identical, except for the specificity with respect to the DNA sequence with which they interact. We discuss the correlation of the variation in polypeptide sequence with recognition specificities.
Use of a β‐lactamase fusion vector to investigate the organization of penicillin‐binding protein 1B in the cytoplasmic membrane of Escherichia coli
Authors: Edelman A. , Bowler L. , Broome‐Smith J. K. , Spratt† B. G.
Published: October 2006

The coding region for the mature form of TEM β–lactamase was fused to random positions within the coding region of the penicillin–binding protein 1B (PBP 1B) gene and the nucleotide sequences across the fusion junctions of 100 in–frame fusions were determined. All fusion proteins that contained at least the NH2–terminal 94 residues of PBP 1B provided individual cells of E. coli with substantial levels of ampicillin resistance, suggesting that the β–lactamase moiety had been translocated to the periplasm. Fusion proteins that contained ≤ 63 residues of PBP 1B possessed β–lactamase activity, but could not protect single cells of E. coli from ampicillin, indicating that the 3–lactamase moiety of these fusion proteins remained in the cytoplasm. The β–lactamase fusion approach suggested a model for the organization of PBP 1B in which the protein is embedded in the cytoplasmic membrane by a single hydrophobic trans–membrane segment (residues 64–87), with a short NH2–terminal domain (residues 1–63), and the remainder of the polypeptide (residues 68–844) exposed on the periplasmic side of the cytoplasmic membrane. The proposed model for the organization of PBP 1B was supported by experiments which showed that the protein was completely digested by proteinase K added from the periplasmic side of the cytoplasmic membrane but was only slightly reduced in size by protease attack from the cytoplasmic side of the membrane.
Regulation of alcR, the positive regulatory gene of the ethanol utilization regulon of Aspergillus nidulans
Authors: Locklngton R. , Scazzocchio C. , Sequeval D. , Mathieu M. , Felenbok B.
Published: October 2006

The alcR positive control gene is necessary for the expression of both alcA (coding for alcohol dehydro‐genase ADH I.) and aldA (coding for aldehyde dehydro‐genase, AldDH) in Aspergillus nidulans. Using a cloned alcR probe and Northern blots analysis we show that: (1)alcR itself is inducible; (2)alcR inducibility depends on the expression of the alcR gene Itself; and (3) alcR is subject to carbon catabolite repression and its expression Is controlled by the negatively acting creA wide specificity gene. The repression of alcR is sufficient to explain the cariaon catabolite repression of ADH I and AldDH.